| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.commons.text; |
| |
| import java.util.ArrayList; |
| import java.util.Enumeration; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Properties; |
| |
| import org.apache.commons.lang3.Validate; |
| import org.apache.commons.text.lookup.StringLookup; |
| import org.apache.commons.text.lookup.StringLookupFactory; |
| import org.apache.commons.text.matcher.StringMatcher; |
| import org.apache.commons.text.matcher.StringMatcherFactory; |
| |
| /** |
| * Substitutes variables within a string by values. |
| * <p> |
| * This class takes a piece of text and substitutes all the variables within it. The default definition of a variable is |
| * <code>${variableName}</code>. The prefix and suffix can be changed via constructors and set methods. |
| * <p> |
| * Variable values are typically resolved from a map, but could also be resolved from system properties, or by supplying |
| * a custom variable resolver. |
| * <p> |
| * The simplest example is to use this class to replace Java System properties. For example: |
| * |
| * <pre> |
| * StringSubstitutor |
| * .replaceSystemProperties("You are running with java.version = ${java.version} and os.name = ${os.name}."); |
| * </pre> |
| * <p> |
| * Typical usage of this class follows the following pattern: First an instance is created and initialized with the map |
| * that contains the values for the available variables. If a prefix and/or suffix for variables should be used other |
| * than the default ones, the appropriate settings can be performed. After that the <code>replace()</code> method can be |
| * called passing in the source text for interpolation. In the returned text all variable references (as long as their |
| * values are known) will be resolved. The following example demonstrates this: |
| * |
| * <pre> |
| * Map valuesMap = HashMap(); |
| * valuesMap.put("animal", "quick brown fox"); |
| * valuesMap.put("target", "lazy dog"); |
| * String templateString = "The ${animal} jumped over the ${target}."; |
| * StringSubstitutor sub = new StringSubstitutor(valuesMap); |
| * String resolvedString = sub.replace(templateString); |
| * </pre> |
| * |
| * yielding: |
| * |
| * <pre> |
| * The quick brown fox jumped over the lazy dog. |
| * </pre> |
| * <p> |
| * Also, this class allows to set a default value for unresolved variables. The default value for a variable can be |
| * appended to the variable name after the variable default value delimiter. The default value of the variable default |
| * value delimiter is ':-', as in bash and other *nix shells, as those are arguably where the default ${} delimiter set |
| * originated. The variable default value delimiter can be manually set by calling |
| * {@link #setValueDelimiterMatcher(StringMatcher)}, {@link #setValueDelimiter(char)} or |
| * {@link #setValueDelimiter(String)}. The following shows an example with variable default value settings: |
| * |
| * <pre> |
| * Map valuesMap = HashMap(); |
| * valuesMap.put("animal", "quick brown fox"); |
| * valuesMap.put("target", "lazy dog"); |
| * String templateString = "The ${animal} jumped over the ${target}. ${undefined.number:-1234567890}."; |
| * StringSubstitutor sub = new StringSubstitutor(valuesMap); |
| * String resolvedString = sub.replace(templateString); |
| * </pre> |
| * |
| * yielding: |
| * |
| * <pre> |
| * The quick brown fox jumped over the lazy dog. 1234567890. |
| * </pre> |
| * <p> |
| * In addition to this usage pattern there are some static convenience methods that cover the most common use cases. |
| * These methods can be used without the need of manually creating an instance. However if multiple replace operations |
| * are to be performed, creating and reusing an instance of this class will be more efficient. |
| * <p> |
| * Variable replacement works in a recursive way. Thus, if a variable value contains a variable then that variable will |
| * also be replaced. Cyclic replacements are detected and will cause an exception to be thrown. |
| * <p> |
| * Sometimes the interpolation's result must contain a variable prefix. As an example take the following source text: |
| * |
| * <pre> |
| * The variable ${${name}} must be used. |
| * </pre> |
| * |
| * Here only the variable's name referred to in the text should be replaced resulting in the text (assuming that the |
| * value of the <code>name</code> variable is <code>x</code>): |
| * |
| * <pre> |
| * The variable ${x} must be used. |
| * </pre> |
| * |
| * To achieve this effect there are two possibilities: Either set a different prefix and suffix for variables which do |
| * not conflict with the result text you want to produce. The other possibility is to use the escape character, by |
| * default '$'. If this character is placed before a variable reference, this reference is ignored and won't be |
| * replaced. For example: |
| * |
| * <pre> |
| * The variable $${${name}} must be used. |
| * </pre> |
| * <p> |
| * In some complex scenarios you might even want to perform substitution in the names of variables, for instance |
| * |
| * <pre> |
| * ${jre-${java.specification.version}} |
| * </pre> |
| * |
| * <code>StringSubstitutor</code> supports this recursive substitution in variable names, but it has to be enabled |
| * explicitly by setting the {@link #setEnableSubstitutionInVariables(boolean) enableSubstitutionInVariables} property |
| * to <b>true</b>. |
| * <p> |
| * This class is <b>not</b> thread safe. |
| * </p> |
| * |
| * @since 1.3 |
| */ |
| public class StringSubstitutor { |
| |
| /** |
| * The default variable default separator. |
| * |
| * @since 1.5. |
| */ |
| public static final String DEFAULT_VAR_DEFAULT = ":-"; |
| |
| /** |
| * The default variable end separator. |
| * |
| * @since 1.5. |
| */ |
| public static final String DEFAULT_VAR_END = "}"; |
| |
| /** |
| * The default variable start separator. |
| * |
| * @since 1.5. |
| */ |
| public static final String DEFAULT_VAR_START = "${"; |
| |
| /** |
| * Constant for the default escape character. |
| */ |
| public static final char DEFAULT_ESCAPE = '$'; |
| |
| /** |
| * Constant for the default variable prefix. |
| */ |
| public static final StringMatcher DEFAULT_PREFIX = StringMatcherFactory.INSTANCE.stringMatcher(DEFAULT_VAR_START); |
| |
| /** |
| * Constant for the default variable suffix. |
| */ |
| public static final StringMatcher DEFAULT_SUFFIX = StringMatcherFactory.INSTANCE.stringMatcher(DEFAULT_VAR_END); |
| |
| /** |
| * Constant for the default value delimiter of a variable. |
| */ |
| public static final StringMatcher DEFAULT_VALUE_DELIMITER = StringMatcherFactory.INSTANCE.stringMatcher(DEFAULT_VAR_DEFAULT); |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Replaces all the occurrences of variables in the given source object with their matching values from the map. |
| * |
| * @param <V> |
| * the type of the values in the map |
| * @param source |
| * the source text containing the variables to substitute, null returns null |
| * @param valueMap |
| * the map with the values, may be null |
| * @return the result of the replace operation |
| */ |
| public static <V> String replace(final Object source, final Map<String, V> valueMap) { |
| return new StringSubstitutor(valueMap).replace(source); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables in the given source object with their matching values from the map. |
| * This method allows to specify a custom variable prefix and suffix |
| * |
| * @param <V> |
| * the type of the values in the map |
| * @param source |
| * the source text containing the variables to substitute, null returns null |
| * @param valueMap |
| * the map with the values, may be null |
| * @param prefix |
| * the prefix of variables, not null |
| * @param suffix |
| * the suffix of variables, not null |
| * @return the result of the replace operation |
| * @throws IllegalArgumentException |
| * if the prefix or suffix is null |
| */ |
| public static <V> String replace(final Object source, final Map<String, V> valueMap, final String prefix, |
| final String suffix) { |
| return new StringSubstitutor(valueMap, prefix, suffix).replace(source); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables in the given source object with their matching values from the |
| * properties. |
| * |
| * @param source |
| * the source text containing the variables to substitute, null returns null |
| * @param valueProperties |
| * the properties with values, may be null |
| * @return the result of the replace operation |
| */ |
| public static String replace(final Object source, final Properties valueProperties) { |
| if (valueProperties == null) { |
| return source.toString(); |
| } |
| final Map<String, String> valueMap = new HashMap<>(); |
| final Enumeration<?> propNames = valueProperties.propertyNames(); |
| while (propNames.hasMoreElements()) { |
| final String propName = (String) propNames.nextElement(); |
| final String propValue = valueProperties.getProperty(propName); |
| valueMap.put(propName, propValue); |
| } |
| return StringSubstitutor.replace(source, valueMap); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables in the given source object with their matching values from the system |
| * properties. |
| * |
| * @param source |
| * the source text containing the variables to substitute, null returns null |
| * @return the result of the replace operation |
| */ |
| public static String replaceSystemProperties(final Object source) { |
| return new StringSubstitutor(StringLookupFactory.INSTANCE.systemPropertyStringLookup()).replace(source); |
| } |
| |
| /** |
| * Stores the escape character. |
| */ |
| private char escapeChar; |
| |
| /** |
| * Stores the variable prefix. |
| */ |
| private StringMatcher prefixMatcher; |
| |
| /** |
| * Stores the variable suffix. |
| */ |
| private StringMatcher suffixMatcher; |
| |
| /** |
| * Stores the default variable value delimiter. |
| */ |
| private StringMatcher valueDelimiterMatcher; |
| |
| /** |
| * Variable resolution is delegated to an implementor of {@link StringLookup}. |
| */ |
| private StringLookup variableResolver; |
| |
| /** |
| * The flag whether substitution in variable names is enabled. |
| */ |
| private boolean enableSubstitutionInVariables; |
| |
| /** |
| * Whether escapes should be preserved. Default is false; |
| */ |
| private boolean preserveEscapes = false; |
| |
| /** |
| * The flag whether substitution in variable values is disabled. |
| */ |
| private boolean disableSubstitutionInValues; |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Creates a new instance with defaults for variable prefix and suffix and the escaping character. |
| */ |
| public StringSubstitutor() { |
| this((StringLookup) null, DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_ESCAPE); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. Uses defaults for variable prefix and suffix and the escaping |
| * character. |
| * |
| * @param <V> |
| * the type of the values in the map |
| * @param valueMap |
| * the map with the variables' values, may be null |
| */ |
| public <V> StringSubstitutor(final Map<String, V> valueMap) { |
| this(StringLookupFactory.INSTANCE.mapStringLookup(valueMap), DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_ESCAPE); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. Uses a default escaping character. |
| * |
| * @param <V> |
| * the type of the values in the map |
| * @param valueMap |
| * the map with the variables' values, may be null |
| * @param prefix |
| * the prefix for variables, not null |
| * @param suffix |
| * the suffix for variables, not null |
| * @throws IllegalArgumentException |
| * if the prefix or suffix is null |
| */ |
| public <V> StringSubstitutor(final Map<String, V> valueMap, final String prefix, final String suffix) { |
| this(StringLookupFactory.INSTANCE.mapStringLookup(valueMap), prefix, suffix, DEFAULT_ESCAPE); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. |
| * |
| * @param <V> |
| * the type of the values in the map |
| * @param valueMap |
| * the map with the variables' values, may be null |
| * @param prefix |
| * the prefix for variables, not null |
| * @param suffix |
| * the suffix for variables, not null |
| * @param escape |
| * the escape character |
| * @throws IllegalArgumentException |
| * if the prefix or suffix is null |
| */ |
| public <V> StringSubstitutor(final Map<String, V> valueMap, final String prefix, final String suffix, |
| final char escape) { |
| this(StringLookupFactory.INSTANCE.mapStringLookup(valueMap), prefix, suffix, escape); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. |
| * |
| * @param <V> |
| * the type of the values in the map |
| * @param valueMap |
| * the map with the variables' values, may be null |
| * @param prefix |
| * the prefix for variables, not null |
| * @param suffix |
| * the suffix for variables, not null |
| * @param escape |
| * the escape character |
| * @param valueDelimiter |
| * the variable default value delimiter, may be null |
| * @throws IllegalArgumentException |
| * if the prefix or suffix is null |
| */ |
| public <V> StringSubstitutor(final Map<String, V> valueMap, final String prefix, final String suffix, |
| final char escape, final String valueDelimiter) { |
| this(StringLookupFactory.INSTANCE.mapStringLookup(valueMap), prefix, suffix, escape, valueDelimiter); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. |
| * |
| * @param variableResolver |
| * the variable resolver, may be null |
| */ |
| public StringSubstitutor(final StringLookup variableResolver) { |
| this(variableResolver, DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_ESCAPE); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. |
| * |
| * @param variableResolver |
| * the variable resolver, may be null |
| * @param prefix |
| * the prefix for variables, not null |
| * @param suffix |
| * the suffix for variables, not null |
| * @param escape |
| * the escape character |
| * @throws IllegalArgumentException |
| * if the prefix or suffix is null |
| */ |
| public StringSubstitutor(final StringLookup variableResolver, final String prefix, final String suffix, |
| final char escape) { |
| this.setVariableResolver(variableResolver); |
| this.setVariablePrefix(prefix); |
| this.setVariableSuffix(suffix); |
| this.setEscapeChar(escape); |
| this.setValueDelimiterMatcher(DEFAULT_VALUE_DELIMITER); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. |
| * |
| * @param variableResolver |
| * the variable resolver, may be null |
| * @param prefix |
| * the prefix for variables, not null |
| * @param suffix |
| * the suffix for variables, not null |
| * @param escape |
| * the escape character |
| * @param valueDelimiter |
| * the variable default value delimiter string, may be null |
| * @throws IllegalArgumentException |
| * if the prefix or suffix is null |
| */ |
| public StringSubstitutor(final StringLookup variableResolver, final String prefix, final String suffix, |
| final char escape, final String valueDelimiter) { |
| this.setVariableResolver(variableResolver); |
| this.setVariablePrefix(prefix); |
| this.setVariableSuffix(suffix); |
| this.setEscapeChar(escape); |
| this.setValueDelimiter(valueDelimiter); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. |
| * |
| * @param variableResolver |
| * the variable resolver, may be null |
| * @param prefixMatcher |
| * the prefix for variables, not null |
| * @param suffixMatcher |
| * the suffix for variables, not null |
| * @param escape |
| * the escape character |
| * @throws IllegalArgumentException |
| * if the prefix or suffix is null |
| */ |
| public StringSubstitutor(final StringLookup variableResolver, final StringMatcher prefixMatcher, |
| final StringMatcher suffixMatcher, final char escape) { |
| this(variableResolver, prefixMatcher, suffixMatcher, escape, DEFAULT_VALUE_DELIMITER); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. |
| * |
| * @param variableResolver |
| * the variable resolver, may be null |
| * @param prefixMatcher |
| * the prefix for variables, not null |
| * @param suffixMatcher |
| * the suffix for variables, not null |
| * @param escape |
| * the escape character |
| * @param valueDelimiterMatcher |
| * the variable default value delimiter matcher, may be null |
| * @throws IllegalArgumentException |
| * if the prefix or suffix is null |
| */ |
| public StringSubstitutor(final StringLookup variableResolver, final StringMatcher prefixMatcher, |
| final StringMatcher suffixMatcher, final char escape, final StringMatcher valueDelimiterMatcher) { |
| this.setVariableResolver(variableResolver); |
| this.setVariablePrefixMatcher(prefixMatcher); |
| this.setVariableSuffixMatcher(suffixMatcher); |
| this.setEscapeChar(escape); |
| this.setValueDelimiterMatcher(valueDelimiterMatcher); |
| } |
| |
| /** |
| * Checks if the specified variable is already in the stack (list) of variables. |
| * |
| * @param varName |
| * the variable name to check |
| * @param priorVariables |
| * the list of prior variables |
| */ |
| private void checkCyclicSubstitution(final String varName, final List<String> priorVariables) { |
| if (!priorVariables.contains(varName)) { |
| return; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(256); |
| buf.append("Infinite loop in property interpolation of "); |
| buf.append(priorVariables.remove(0)); |
| buf.append(": "); |
| buf.appendWithSeparators(priorVariables, "->"); |
| throw new IllegalStateException(buf.toString()); |
| } |
| |
| // Escape |
| // ----------------------------------------------------------------------- |
| /** |
| * Returns the escape character. |
| * |
| * @return the character used for escaping variable references |
| */ |
| public char getEscapeChar() { |
| return this.escapeChar; |
| } |
| |
| // Resolver |
| // ----------------------------------------------------------------------- |
| /** |
| * Gets the StringLookup that is used to lookup variables. |
| * |
| * @return the StringLookup |
| */ |
| public StringLookup getStringLookup() { |
| return this.variableResolver; |
| } |
| |
| // Variable Default Value Delimiter |
| // ----------------------------------------------------------------------- |
| /** |
| * Gets the variable default value delimiter matcher currently in use. |
| * <p> |
| * The variable default value delimiter is the character or characters that delimite the variable name and the |
| * variable default value. This delimiter is expressed in terms of a matcher allowing advanced variable default |
| * value delimiter matches. |
| * <p> |
| * If it returns null, then the variable default value resolution is disabled. |
| * |
| * @return the variable default value delimiter matcher in use, may be null |
| */ |
| public StringMatcher getValueDelimiterMatcher() { |
| return valueDelimiterMatcher; |
| } |
| |
| // Prefix |
| // ----------------------------------------------------------------------- |
| /** |
| * Gets the variable prefix matcher currently in use. |
| * <p> |
| * The variable prefix is the character or characters that identify the start of a variable. This prefix is |
| * expressed in terms of a matcher allowing advanced prefix matches. |
| * |
| * @return the prefix matcher in use |
| */ |
| public StringMatcher getVariablePrefixMatcher() { |
| return prefixMatcher; |
| } |
| |
| // Suffix |
| // ----------------------------------------------------------------------- |
| /** |
| * Gets the variable suffix matcher currently in use. |
| * <p> |
| * The variable suffix is the character or characters that identify the end of a variable. This suffix is expressed |
| * in terms of a matcher allowing advanced suffix matches. |
| * |
| * @return the suffix matcher in use |
| */ |
| public StringMatcher getVariableSuffixMatcher() { |
| return suffixMatcher; |
| } |
| |
| /** |
| * Returns a flag whether substitution is disabled in variable values.If set to <b>true</b>, the values of variables |
| * can contain other variables will not be processed and substituted original variable is evaluated, e.g. |
| * |
| * <pre> |
| * Map valuesMap = HashMap(); |
| * valuesMap.put("name", "Douglas ${surname}"); |
| * valuesMap.put("surname", "Crockford"); |
| * String templateString = "Hi ${name}"; |
| * StrSubstitutor sub = new StrSubstitutor(valuesMap); |
| * String resolvedString = sub.replace(templateString); |
| * </pre> |
| * |
| * yielding: |
| * |
| * <pre> |
| * Hi Douglas ${surname} |
| * </pre> |
| * |
| * @return the substitution in variable values flag |
| */ |
| public boolean isDisableSubstitutionInValues() { |
| return disableSubstitutionInValues; |
| } |
| |
| // Substitution support in variable names |
| // ----------------------------------------------------------------------- |
| /** |
| * Returns a flag whether substitution is done in variable names. |
| * |
| * @return the substitution in variable names flag |
| */ |
| public boolean isEnableSubstitutionInVariables() { |
| return enableSubstitutionInVariables; |
| } |
| |
| /** |
| * Returns the flag controlling whether escapes are preserved during substitution. |
| * |
| * @return the preserve escape flag |
| */ |
| public boolean isPreserveEscapes() { |
| return preserveEscapes; |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Replaces all the occurrences of variables with their matching values from the resolver using the given source |
| * array as a template. The array is not altered by this method. |
| * |
| * @param source |
| * the character array to replace in, not altered, null returns null |
| * @return the result of the replace operation |
| */ |
| public String replace(final char[] source) { |
| if (source == null) { |
| return null; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(source.length).append(source); |
| substitute(buf, 0, source.length); |
| return buf.toString(); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables with their matching values from the resolver using the given source |
| * array as a template. The array is not altered by this method. |
| * <p> |
| * Only the specified portion of the array will be processed. The rest of the array is not processed, and is not |
| * returned. |
| * |
| * @param source |
| * the character array to replace in, not altered, null returns null |
| * @param offset |
| * the start offset within the array, must be valid |
| * @param length |
| * the length within the array to be processed, must be valid |
| * @return the result of the replace operation |
| */ |
| public String replace(final char[] source, final int offset, final int length) { |
| if (source == null) { |
| return null; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(length).append(source, offset, length); |
| substitute(buf, 0, length); |
| return buf.toString(); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables with their matching values from the resolver using the given source as |
| * a template. The source is not altered by this method. |
| * |
| * @param source |
| * the buffer to use as a template, not changed, null returns null |
| * @return the result of the replace operation |
| */ |
| public String replace(final CharSequence source) { |
| if (source == null) { |
| return null; |
| } |
| return replace(source, 0, source.length()); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables with their matching values from the resolver using the given source as |
| * a template. The source is not altered by this method. |
| * <p> |
| * Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, and is not |
| * returned. |
| * |
| * @param source |
| * the buffer to use as a template, not changed, null returns null |
| * @param offset |
| * the start offset within the array, must be valid |
| * @param length |
| * the length within the array to be processed, must be valid |
| * @return the result of the replace operation |
| */ |
| public String replace(final CharSequence source, final int offset, final int length) { |
| if (source == null) { |
| return null; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(length).append(source, offset, length); |
| substitute(buf, 0, length); |
| return buf.toString(); |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Replaces all the occurrences of variables in the given source object with their matching values from the |
| * resolver. The input source object is converted to a string using <code>toString</code> and is not altered. |
| * |
| * @param source |
| * the source to replace in, null returns null |
| * @return the result of the replace operation |
| */ |
| public String replace(final Object source) { |
| if (source == null) { |
| return null; |
| } |
| final TextStringBuilder buf = new TextStringBuilder().append(source); |
| substitute(buf, 0, buf.length()); |
| return buf.toString(); |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Replaces all the occurrences of variables with their matching values from the resolver using the given source |
| * builder as a template. The builder is not altered by this method. |
| * |
| * @param source |
| * the builder to use as a template, not changed, null returns null |
| * @return the result of the replace operation |
| */ |
| public String replace(final TextStringBuilder source) { |
| if (source == null) { |
| return null; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(source.length()).append(source); |
| substitute(buf, 0, buf.length()); |
| return buf.toString(); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables with their matching values from the resolver using the given source |
| * builder as a template. The builder is not altered by this method. |
| * <p> |
| * Only the specified portion of the builder will be processed. The rest of the builder is not processed, and is not |
| * returned. |
| * |
| * @param source |
| * the builder to use as a template, not changed, null returns null |
| * @param offset |
| * the start offset within the array, must be valid |
| * @param length |
| * the length within the array to be processed, must be valid |
| * @return the result of the replace operation |
| */ |
| public String replace(final TextStringBuilder source, final int offset, final int length) { |
| if (source == null) { |
| return null; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(length).append(source, offset, length); |
| substitute(buf, 0, length); |
| return buf.toString(); |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Replaces all the occurrences of variables with their matching values from the resolver using the given source |
| * string as a template. |
| * |
| * @param source |
| * the string to replace in, null returns null |
| * @return the result of the replace operation |
| */ |
| public String replace(final String source) { |
| if (source == null) { |
| return null; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(source); |
| if (!substitute(buf, 0, source.length())) { |
| return source; |
| } |
| return buf.toString(); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables with their matching values from the resolver using the given source |
| * string as a template. |
| * <p> |
| * Only the specified portion of the string will be processed. The rest of the string is not processed, and is not |
| * returned. |
| * |
| * @param source |
| * the string to replace in, null returns null |
| * @param offset |
| * the start offset within the array, must be valid |
| * @param length |
| * the length within the array to be processed, must be valid |
| * @return the result of the replace operation |
| */ |
| public String replace(final String source, final int offset, final int length) { |
| if (source == null) { |
| return null; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(length).append(source, offset, length); |
| if (!substitute(buf, 0, length)) { |
| return source.substring(offset, offset + length); |
| } |
| return buf.toString(); |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Replaces all the occurrences of variables with their matching values from the resolver using the given source |
| * buffer as a template. The buffer is not altered by this method. |
| * |
| * @param source |
| * the buffer to use as a template, not changed, null returns null |
| * @return the result of the replace operation |
| */ |
| public String replace(final StringBuffer source) { |
| if (source == null) { |
| return null; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(source.length()).append(source); |
| substitute(buf, 0, buf.length()); |
| return buf.toString(); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables with their matching values from the resolver using the given source |
| * buffer as a template. The buffer is not altered by this method. |
| * <p> |
| * Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, and is not |
| * returned. |
| * |
| * @param source |
| * the buffer to use as a template, not changed, null returns null |
| * @param offset |
| * the start offset within the array, must be valid |
| * @param length |
| * the length within the array to be processed, must be valid |
| * @return the result of the replace operation |
| */ |
| public String replace(final StringBuffer source, final int offset, final int length) { |
| if (source == null) { |
| return null; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(length).append(source, offset, length); |
| substitute(buf, 0, length); |
| return buf.toString(); |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Replaces all the occurrences of variables within the given source builder with their matching values from the |
| * resolver. |
| * |
| * @param source |
| * the builder to replace in, updated, null returns zero |
| * @return true if altered |
| */ |
| public boolean replaceIn(final TextStringBuilder source) { |
| if (source == null) { |
| return false; |
| } |
| return substitute(source, 0, source.length()); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables within the given source builder with their matching values from the |
| * resolver. |
| * <p> |
| * Only the specified portion of the builder will be processed. The rest of the builder is not processed, but it is |
| * not deleted. |
| * |
| * @param source |
| * the builder to replace in, null returns zero |
| * @param offset |
| * the start offset within the array, must be valid |
| * @param length |
| * the length within the builder to be processed, must be valid |
| * @return true if altered |
| */ |
| public boolean replaceIn(final TextStringBuilder source, final int offset, final int length) { |
| if (source == null) { |
| return false; |
| } |
| return substitute(source, offset, length); |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Replaces all the occurrences of variables within the given source buffer with their matching values from the |
| * resolver. The buffer is updated with the result. |
| * |
| * @param source |
| * the buffer to replace in, updated, null returns zero |
| * @return true if altered |
| */ |
| public boolean replaceIn(final StringBuffer source) { |
| if (source == null) { |
| return false; |
| } |
| return replaceIn(source, 0, source.length()); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables within the given source buffer with their matching values from the |
| * resolver. The buffer is updated with the result. |
| * <p> |
| * Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, but it is |
| * not deleted. |
| * |
| * @param source |
| * the buffer to replace in, updated, null returns zero |
| * @param offset |
| * the start offset within the array, must be valid |
| * @param length |
| * the length within the buffer to be processed, must be valid |
| * @return true if altered |
| */ |
| public boolean replaceIn(final StringBuffer source, final int offset, final int length) { |
| if (source == null) { |
| return false; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(length).append(source, offset, length); |
| if (!substitute(buf, 0, length)) { |
| return false; |
| } |
| source.replace(offset, offset + length, buf.toString()); |
| return true; |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Replaces all the occurrences of variables within the given source buffer with their matching values from the |
| * resolver. The buffer is updated with the result. |
| * |
| * @param source |
| * the buffer to replace in, updated, null returns zero |
| * @return true if altered |
| */ |
| public boolean replaceIn(final StringBuilder source) { |
| if (source == null) { |
| return false; |
| } |
| return replaceIn(source, 0, source.length()); |
| } |
| |
| /** |
| * Replaces all the occurrences of variables within the given source builder with their matching values from the |
| * resolver. The builder is updated with the result. |
| * <p> |
| * Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, but it is |
| * not deleted. |
| * |
| * @param source |
| * the buffer to replace in, updated, null returns zero |
| * @param offset |
| * the start offset within the array, must be valid |
| * @param length |
| * the length within the buffer to be processed, must be valid |
| * @return true if altered |
| */ |
| public boolean replaceIn(final StringBuilder source, final int offset, final int length) { |
| if (source == null) { |
| return false; |
| } |
| final TextStringBuilder buf = new TextStringBuilder(length).append(source, offset, length); |
| if (!substitute(buf, 0, length)) { |
| return false; |
| } |
| source.replace(offset, offset + length, buf.toString()); |
| return true; |
| } |
| |
| /** |
| * Internal method that resolves the value of a variable. |
| * <p> |
| * Most users of this class do not need to call this method. This method is called automatically by the substitution |
| * process. |
| * <p> |
| * Writers of subclasses can override this method if they need to alter how each substitution occurs. The method is |
| * passed the variable's name and must return the corresponding value. This implementation uses the |
| * {@link #getStringLookup()} with the variable's name as the key. |
| * |
| * @param variableName |
| * the name of the variable, not null |
| * @param buf |
| * the buffer where the substitution is occurring, not null |
| * @param startPos |
| * the start position of the variable including the prefix, valid |
| * @param endPos |
| * the end position of the variable including the suffix, valid |
| * @return the variable's value or <b>null</b> if the variable is unknown |
| */ |
| protected String resolveVariable(final String variableName, final TextStringBuilder buf, final int startPos, |
| final int endPos) { |
| final StringLookup resolver = getStringLookup(); |
| if (resolver == null) { |
| return null; |
| } |
| return resolver.lookup(variableName); |
| } |
| |
| /** |
| * Sets a flag whether substitution is done in variable values (recursive). |
| * |
| * @param disableSubstitutionInValues |
| * true if substitution in variable value are disabled |
| * @return this, to enable chaining |
| */ |
| public StringSubstitutor setDisableSubstitutionInValues(final boolean disableSubstitutionInValues) { |
| this.disableSubstitutionInValues = disableSubstitutionInValues; |
| return this; |
| } |
| |
| /** |
| * Sets a flag whether substitution is done in variable names. If set to <b>true</b>, the names of variables can |
| * contain other variables which are processed first before the original variable is evaluated, e.g. |
| * <code>${jre-${java.version}}</code>. The default value is <b>false</b>. |
| * |
| * @param enableSubstitutionInVariables |
| * the new value of the flag |
| * @return this, to enable chaining |
| */ |
| public StringSubstitutor setEnableSubstitutionInVariables(final boolean enableSubstitutionInVariables) { |
| this.enableSubstitutionInVariables = enableSubstitutionInVariables; |
| return this; |
| } |
| |
| /** |
| * Sets the escape character. If this character is placed before a variable reference in the source text, this |
| * variable will be ignored. |
| * |
| * @param escapeCharacter |
| * the escape character (0 for disabling escaping) |
| * @return this, to enable chaining |
| */ |
| public StringSubstitutor setEscapeChar(final char escapeCharacter) { |
| this.escapeChar = escapeCharacter; |
| return this; |
| } |
| |
| /** |
| * Sets a flag controlling whether escapes are preserved during substitution. If set to <b>true</b>, the escape |
| * character is retained during substitution (e.g. <code>$${this-is-escaped}</code> remains |
| * <code>$${this-is-escaped}</code>). If set to <b>false</b>, the escape character is removed during substitution |
| * (e.g. <code>$${this-is-escaped}</code> becomes <code>${this-is-escaped}</code>). The default value is |
| * <b>false</b> |
| * |
| * @param preserveEscapes |
| * true if escapes are to be preserved |
| * @return this, to enable chaining |
| */ |
| public StringSubstitutor setPreserveEscapes(final boolean preserveEscapes) { |
| this.preserveEscapes = preserveEscapes; |
| return this; |
| } |
| |
| /** |
| * Sets the variable default value delimiter to use. |
| * <p> |
| * The variable default value delimiter is the character or characters that delimite the variable name and the |
| * variable default value. This method allows a single character variable default value delimiter to be easily set. |
| * |
| * @param valueDelimiter |
| * the variable default value delimiter character to use |
| * @return this, to enable chaining |
| */ |
| public StringSubstitutor setValueDelimiter(final char valueDelimiter) { |
| return setValueDelimiterMatcher(StringMatcherFactory.INSTANCE.charMatcher(valueDelimiter)); |
| } |
| |
| /** |
| * Sets the variable default value delimiter to use. |
| * <p> |
| * The variable default value delimiter is the character or characters that delimite the variable name and the |
| * variable default value. This method allows a string variable default value delimiter to be easily set. |
| * <p> |
| * If the <code>valueDelimiter</code> is null or empty string, then the variable default value resolution becomes |
| * disabled. |
| * |
| * @param valueDelimiter |
| * the variable default value delimiter string to use, may be null or empty |
| * @return this, to enable chaining |
| */ |
| public StringSubstitutor setValueDelimiter(final String valueDelimiter) { |
| if (valueDelimiter == null || valueDelimiter.length() == 0) { |
| setValueDelimiterMatcher(null); |
| return this; |
| } |
| return setValueDelimiterMatcher(StringMatcherFactory.INSTANCE.stringMatcher(valueDelimiter)); |
| } |
| |
| /** |
| * Sets the variable default value delimiter matcher to use. |
| * <p> |
| * The variable default value delimiter is the character or characters that delimite the variable name and the |
| * variable default value. This delimiter is expressed in terms of a matcher allowing advanced variable default |
| * value delimiter matches. |
| * <p> |
| * If the <code>valueDelimiterMatcher</code> is null, then the variable default value resolution becomes disabled. |
| * |
| * @param valueDelimiterMatcher |
| * variable default value delimiter matcher to use, may be null |
| * @return this, to enable chaining |
| */ |
| public StringSubstitutor setValueDelimiterMatcher(final StringMatcher valueDelimiterMatcher) { |
| this.valueDelimiterMatcher = valueDelimiterMatcher; |
| return this; |
| } |
| |
| /** |
| * Sets the variable prefix to use. |
| * <p> |
| * The variable prefix is the character or characters that identify the start of a variable. This method allows a |
| * single character prefix to be easily set. |
| * |
| * @param prefix |
| * the prefix character to use |
| * @return this, to enable chaining |
| */ |
| public StringSubstitutor setVariablePrefix(final char prefix) { |
| return setVariablePrefixMatcher(StringMatcherFactory.INSTANCE.charMatcher(prefix)); |
| } |
| |
| /** |
| * Sets the variable prefix to use. |
| * <p> |
| * The variable prefix is the character or characters that identify the start of a variable. This method allows a |
| * string prefix to be easily set. |
| * |
| * @param prefix |
| * the prefix for variables, not null |
| * @return this, to enable chaining |
| * @throws IllegalArgumentException |
| * if the prefix is null |
| */ |
| public StringSubstitutor setVariablePrefix(final String prefix) { |
| Validate.isTrue(prefix != null, "Variable prefix must not be null!"); |
| return setVariablePrefixMatcher(StringMatcherFactory.INSTANCE.stringMatcher(prefix)); |
| } |
| |
| /** |
| * Sets the variable prefix matcher currently in use. |
| * <p> |
| * The variable prefix is the character or characters that identify the start of a variable. This prefix is |
| * expressed in terms of a matcher allowing advanced prefix matches. |
| * |
| * @param prefixMatcher |
| * the prefix matcher to use, null ignored |
| * @return this, to enable chaining |
| * @throws IllegalArgumentException |
| * if the prefix matcher is null |
| */ |
| public StringSubstitutor setVariablePrefixMatcher(final StringMatcher prefixMatcher) { |
| Validate.isTrue(prefixMatcher != null, "Variable prefix matcher must not be null!"); |
| this.prefixMatcher = prefixMatcher; |
| return this; |
| } |
| |
| /** |
| * Sets the VariableResolver that is used to lookup variables. |
| * |
| * @param variableResolver |
| * the VariableResolver |
| * @return this, to enable chaining |
| */ |
| public StringSubstitutor setVariableResolver(final StringLookup variableResolver) { |
| this.variableResolver = variableResolver; |
| return this; |
| } |
| |
| /** |
| * Sets the variable suffix to use. |
| * <p> |
| * The variable suffix is the character or characters that identify the end of a variable. This method allows a |
| * single character suffix to be easily set. |
| * |
| * @param suffix |
| * the suffix character to use |
| * @return this, to enable chaining |
| */ |
| public StringSubstitutor setVariableSuffix(final char suffix) { |
| return setVariableSuffixMatcher(StringMatcherFactory.INSTANCE.charMatcher(suffix)); |
| } |
| |
| /** |
| * Sets the variable suffix to use. |
| * <p> |
| * The variable suffix is the character or characters that identify the end of a variable. This method allows a |
| * string suffix to be easily set. |
| * |
| * @param suffix |
| * the suffix for variables, not null |
| * @return this, to enable chaining |
| * @throws IllegalArgumentException |
| * if the suffix is null |
| */ |
| public StringSubstitutor setVariableSuffix(final String suffix) { |
| Validate.isTrue(suffix != null, "Variable suffix must not be null!"); |
| return setVariableSuffixMatcher(StringMatcherFactory.INSTANCE.stringMatcher(suffix)); |
| } |
| |
| /** |
| * Sets the variable suffix matcher currently in use. |
| * <p> |
| * The variable suffix is the character or characters that identify the end of a variable. This suffix is expressed |
| * in terms of a matcher allowing advanced suffix matches. |
| * |
| * @param suffixMatcher |
| * the suffix matcher to use, null ignored |
| * @return this, to enable chaining |
| * @throws IllegalArgumentException |
| * if the suffix matcher is null |
| */ |
| public StringSubstitutor setVariableSuffixMatcher(final StringMatcher suffixMatcher) { |
| Validate.isTrue(suffixMatcher != null, "Variable suffix matcher must not be null!"); |
| this.suffixMatcher = suffixMatcher; |
| return this; |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Internal method that substitutes the variables. |
| * <p> |
| * Most users of this class do not need to call this method. This method will be called automatically by another |
| * (public) method. |
| * <p> |
| * Writers of subclasses can override this method if they need access to the substitution process at the start or |
| * end. |
| * |
| * @param buf |
| * the string builder to substitute into, not null |
| * @param offset |
| * the start offset within the builder, must be valid |
| * @param length |
| * the length within the builder to be processed, must be valid |
| * @return true if altered |
| */ |
| protected boolean substitute(final TextStringBuilder buf, final int offset, final int length) { |
| return substitute(buf, offset, length, null) > 0; |
| } |
| |
| /** |
| * Recursive handler for multiple levels of interpolation. This is the main interpolation method, which resolves the |
| * values of all variable references contained in the passed in text. |
| * |
| * @param buf |
| * the string builder to substitute into, not null |
| * @param offset |
| * the start offset within the builder, must be valid |
| * @param length |
| * the length within the builder to be processed, must be valid |
| * @param priorVariables |
| * the stack keeping track of the replaced variables, may be null |
| * @return the length change that occurs, unless priorVariables is null when the int represents a boolean flag as to |
| * whether any change occurred. |
| */ |
| private int substitute(final TextStringBuilder buf, final int offset, final int length, |
| List<String> priorVariables) { |
| final StringMatcher pfxMatcher = getVariablePrefixMatcher(); |
| final StringMatcher suffMatcher = getVariableSuffixMatcher(); |
| final char escape = getEscapeChar(); |
| final StringMatcher valueDelimMatcher = getValueDelimiterMatcher(); |
| final boolean substitutionInVariablesEnabled = isEnableSubstitutionInVariables(); |
| final boolean substitutionInValuesDisabled = isDisableSubstitutionInValues(); |
| |
| final boolean top = priorVariables == null; |
| boolean altered = false; |
| int lengthChange = 0; |
| char[] chars = buf.buffer; |
| int bufEnd = offset + length; |
| int pos = offset; |
| while (pos < bufEnd) { |
| final int startMatchLen = pfxMatcher.isMatch(chars, pos, offset, bufEnd); |
| if (startMatchLen == 0) { |
| pos++; |
| } else { |
| // found variable start marker |
| if (pos > offset && chars[pos - 1] == escape) { |
| // escaped |
| if (preserveEscapes) { |
| pos++; |
| continue; |
| } |
| buf.deleteCharAt(pos - 1); |
| chars = buf.buffer; // in case buffer was altered |
| lengthChange--; |
| altered = true; |
| bufEnd--; |
| } else { |
| // find suffix |
| final int startPos = pos; |
| pos += startMatchLen; |
| int endMatchLen = 0; |
| int nestedVarCount = 0; |
| while (pos < bufEnd) { |
| if (substitutionInVariablesEnabled && pfxMatcher.isMatch(chars, pos, offset, bufEnd) != 0) { |
| // found a nested variable start |
| endMatchLen = pfxMatcher.isMatch(chars, pos, offset, bufEnd); |
| nestedVarCount++; |
| pos += endMatchLen; |
| continue; |
| } |
| |
| endMatchLen = suffMatcher.isMatch(chars, pos, offset, bufEnd); |
| if (endMatchLen == 0) { |
| pos++; |
| } else { |
| // found variable end marker |
| if (nestedVarCount == 0) { |
| String varNameExpr = new String(chars, startPos + startMatchLen, |
| pos - startPos - startMatchLen); |
| if (substitutionInVariablesEnabled) { |
| final TextStringBuilder bufName = new TextStringBuilder(varNameExpr); |
| substitute(bufName, 0, bufName.length()); |
| varNameExpr = bufName.toString(); |
| } |
| pos += endMatchLen; |
| final int endPos = pos; |
| |
| String varName = varNameExpr; |
| String varDefaultValue = null; |
| |
| if (valueDelimMatcher != null) { |
| final char[] varNameExprChars = varNameExpr.toCharArray(); |
| int valueDelimiterMatchLen = 0; |
| for (int i = 0; i < varNameExprChars.length; i++) { |
| // if there's any nested variable when nested variable substitution disabled, |
| // then stop resolving name and default value. |
| if (!substitutionInVariablesEnabled && pfxMatcher.isMatch(varNameExprChars, i, |
| i, varNameExprChars.length) != 0) { |
| break; |
| } |
| if (valueDelimMatcher.isMatch(varNameExprChars, i, 0, |
| varNameExprChars.length) != 0) { |
| valueDelimiterMatchLen = valueDelimMatcher.isMatch(varNameExprChars, i, 0, |
| varNameExprChars.length); |
| varName = varNameExpr.substring(0, i); |
| varDefaultValue = varNameExpr.substring(i + valueDelimiterMatchLen); |
| break; |
| } |
| } |
| } |
| |
| // on the first call initialize priorVariables |
| if (priorVariables == null) { |
| priorVariables = new ArrayList<>(); |
| priorVariables.add(new String(chars, offset, length)); |
| } |
| |
| // handle cyclic substitution |
| checkCyclicSubstitution(varName, priorVariables); |
| priorVariables.add(varName); |
| |
| // resolve the variable |
| String varValue = resolveVariable(varName, buf, startPos, endPos); |
| if (varValue == null) { |
| varValue = varDefaultValue; |
| } |
| if (varValue != null) { |
| final int varLen = varValue.length(); |
| buf.replace(startPos, endPos, varValue); |
| altered = true; |
| int change = 0; |
| if (!substitutionInValuesDisabled) { // recursive replace |
| change = substitute(buf, startPos, varLen, priorVariables); |
| } |
| change = change + varLen - (endPos - startPos); |
| pos += change; |
| bufEnd += change; |
| lengthChange += change; |
| chars = buf.buffer; // in case buffer was |
| // altered |
| } |
| |
| // remove variable from the cyclic stack |
| priorVariables.remove(priorVariables.size() - 1); |
| break; |
| } |
| nestedVarCount--; |
| pos += endMatchLen; |
| } |
| } |
| } |
| } |
| } |
| if (top) { |
| return altered ? 1 : 0; |
| } |
| return lengthChange; |
| } |
| } |