/* | |
* 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; | |
/** | |
* 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> | |
* StrSubstitutor.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}."; | |
* StrSubstitutor sub = new StrSubstitutor(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(StrMatcher)}, | |
* {@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}."; | |
* StrSubstitutor sub = new StrSubstitutor(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>StrSubstitutor</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 1.0 | |
* @deprecated Deprecated as of 1.3, use {@link StringSubstitutor} instead. This class will be removed in 2.0. | |
*/ | |
@Deprecated | |
public class StrSubstitutor { | |
/** | |
* Constant for the default escape character. | |
*/ | |
public static final char DEFAULT_ESCAPE = '$'; | |
/** | |
* Constant for the default variable prefix. | |
*/ | |
public static final StrMatcher DEFAULT_PREFIX = StrMatcher.stringMatcher("${"); | |
/** | |
* Constant for the default variable suffix. | |
*/ | |
public static final StrMatcher DEFAULT_SUFFIX = StrMatcher.stringMatcher("}"); | |
/** | |
* Constant for the default value delimiter of a variable. | |
*/ | |
public static final StrMatcher DEFAULT_VALUE_DELIMITER = StrMatcher.stringMatcher(":-"); | |
/** | |
* Stores the escape character. | |
*/ | |
private char escapeChar; | |
/** | |
* Stores the variable prefix. | |
*/ | |
private StrMatcher prefixMatcher; | |
/** | |
* Stores the variable suffix. | |
*/ | |
private StrMatcher suffixMatcher; | |
/** | |
* Stores the default variable value delimiter. | |
*/ | |
private StrMatcher valueDelimiterMatcher; | |
/** | |
* Variable resolution is delegated to an implementor of VariableResolver. | |
*/ | |
private StrLookup<?> 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; | |
//----------------------------------------------------------------------- | |
/** | |
* 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 StrSubstitutor(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 StrSubstitutor(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 StrSubstitutor.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 StrSubstitutor(StrLookup.systemPropertiesLookup()).replace(source); | |
} | |
//----------------------------------------------------------------------- | |
/** | |
* Creates a new instance with defaults for variable prefix and suffix | |
* and the escaping character. | |
*/ | |
public StrSubstitutor() { | |
this((StrLookup<?>) 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> StrSubstitutor(final Map<String, V> valueMap) { | |
this(StrLookup.mapLookup(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> StrSubstitutor(final Map<String, V> valueMap, final String prefix, final String suffix) { | |
this(StrLookup.mapLookup(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> StrSubstitutor(final Map<String, V> valueMap, final String prefix, final String suffix, | |
final char escape) { | |
this(StrLookup.mapLookup(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> StrSubstitutor(final Map<String, V> valueMap, final String prefix, final String suffix, | |
final char escape, final String valueDelimiter) { | |
this(StrLookup.mapLookup(valueMap), prefix, suffix, escape, valueDelimiter); | |
} | |
/** | |
* Creates a new instance and initializes it. | |
* | |
* @param variableResolver the variable resolver, may be null | |
*/ | |
public StrSubstitutor(final StrLookup<?> 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 StrSubstitutor(final StrLookup<?> 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 StrSubstitutor(final StrLookup<?> 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 StrSubstitutor( | |
final StrLookup<?> variableResolver, final StrMatcher prefixMatcher, final StrMatcher 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 StrSubstitutor( | |
final StrLookup<?> variableResolver, final StrMatcher prefixMatcher, final StrMatcher suffixMatcher, | |
final char escape, final StrMatcher valueDelimiterMatcher) { | |
this.setVariableResolver(variableResolver); | |
this.setVariablePrefixMatcher(prefixMatcher); | |
this.setVariableSuffixMatcher(suffixMatcher); | |
this.setEscapeChar(escape); | |
this.setValueDelimiterMatcher(valueDelimiterMatcher); | |
} | |
//----------------------------------------------------------------------- | |
/** | |
* 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 StrBuilder buf = new StrBuilder(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 StrBuilder buf = new StrBuilder(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 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 StrBuilder buf = new StrBuilder(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 StrBuilder buf = new StrBuilder(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 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 StrBuilder buf = new StrBuilder(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 StrBuilder buf = new StrBuilder(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 StrBuilder buf = new StrBuilder(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 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 StrBuilder source) { | |
if (source == null) { | |
return null; | |
} | |
final StrBuilder buf = new StrBuilder(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 StrBuilder source, final int offset, final int length) { | |
if (source == null) { | |
return null; | |
} | |
final StrBuilder buf = new StrBuilder(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 StrBuilder buf = new StrBuilder().append(source); | |
substitute(buf, 0, buf.length()); | |
return buf.toString(); | |
} | |
//----------------------------------------------------------------------- | |
/** | |
* 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 StrBuilder buf = new StrBuilder(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 StrBuilder buf = new StrBuilder(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 | |
* 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 StrBuilder 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 StrBuilder source, final int offset, final int length) { | |
if (source == null) { | |
return false; | |
} | |
return substitute(source, offset, length); | |
} | |
//----------------------------------------------------------------------- | |
/** | |
* 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 StrBuilder 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 StrBuilder buf, final int offset, final int length, List<String> priorVariables) { | |
final StrMatcher pfxMatcher = getVariablePrefixMatcher(); | |
final StrMatcher suffMatcher = getVariableSuffixMatcher(); | |
final char escape = getEscapeChar(); | |
final StrMatcher 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 StrBuilder bufName = new StrBuilder(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) { | |
valueDelimiterMatchLen = valueDelimMatcher.isMatch(varNameExprChars, i); | |
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; | |
} | |
/** | |
* 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 StrBuilder buf = new StrBuilder(256); | |
buf.append("Infinite loop in property interpolation of "); | |
buf.append(priorVariables.remove(0)); | |
buf.append(": "); | |
buf.appendWithSeparators(priorVariables, "->"); | |
throw new IllegalStateException(buf.toString()); | |
} | |
/** | |
* 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 #getVariableResolver()} 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 StrBuilder buf, | |
final int startPos, | |
final int endPos) { | |
final StrLookup<?> resolver = getVariableResolver(); | |
if (resolver == null) { | |
return null; | |
} | |
return resolver.lookup(variableName); | |
} | |
// Escape | |
//----------------------------------------------------------------------- | |
/** | |
* Returns the escape character. | |
* | |
* @return the character used for escaping variable references | |
*/ | |
public char getEscapeChar() { | |
return this.escapeChar; | |
} | |
/** | |
* 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) | |
*/ | |
public void setEscapeChar(final char escapeCharacter) { | |
this.escapeChar = escapeCharacter; | |
} | |
// 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 StrMatcher getVariablePrefixMatcher() { | |
return prefixMatcher; | |
} | |
/** | |
* 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 StrSubstitutor setVariablePrefixMatcher(final StrMatcher prefixMatcher) { | |
Validate.isTrue(prefixMatcher != null, "Variable prefix matcher must not be null!"); | |
this.prefixMatcher = prefixMatcher; | |
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 StrSubstitutor setVariablePrefix(final char prefix) { | |
return setVariablePrefixMatcher(StrMatcher.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 StrSubstitutor setVariablePrefix(final String prefix) { | |
Validate.isTrue(prefix != null, "Variable prefix must not be null!"); | |
return setVariablePrefixMatcher(StrMatcher.stringMatcher(prefix)); | |
} | |
// 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 StrMatcher getVariableSuffixMatcher() { | |
return suffixMatcher; | |
} | |
/** | |
* 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 StrSubstitutor setVariableSuffixMatcher(final StrMatcher suffixMatcher) { | |
Validate.isTrue(suffixMatcher != null, "Variable suffix matcher must not be null!"); | |
this.suffixMatcher = suffixMatcher; | |
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 StrSubstitutor setVariableSuffix(final char suffix) { | |
return setVariableSuffixMatcher(StrMatcher.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 StrSubstitutor setVariableSuffix(final String suffix) { | |
Validate.isTrue(suffix != null, "Variable suffix must not be null!"); | |
return setVariableSuffixMatcher(StrMatcher.stringMatcher(suffix)); | |
} | |
// 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 StrMatcher getValueDelimiterMatcher() { | |
return valueDelimiterMatcher; | |
} | |
/** | |
* 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 StrSubstitutor setValueDelimiterMatcher(final StrMatcher valueDelimiterMatcher) { | |
this.valueDelimiterMatcher = valueDelimiterMatcher; | |
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 StrSubstitutor setValueDelimiter(final char valueDelimiter) { | |
return setValueDelimiterMatcher(StrMatcher.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 StrSubstitutor setValueDelimiter(final String valueDelimiter) { | |
if (valueDelimiter == null || valueDelimiter.length() == 0) { | |
setValueDelimiterMatcher(null); | |
return this; | |
} | |
return setValueDelimiterMatcher(StrMatcher.stringMatcher(valueDelimiter)); | |
} | |
// Resolver | |
//----------------------------------------------------------------------- | |
/** | |
* Gets the VariableResolver that is used to lookup variables. | |
* | |
* @return the VariableResolver | |
*/ | |
public StrLookup<?> getVariableResolver() { | |
return this.variableResolver; | |
} | |
/** | |
* Sets the VariableResolver that is used to lookup variables. | |
* | |
* @param variableResolver the VariableResolver | |
*/ | |
public void setVariableResolver(final StrLookup<?> variableResolver) { | |
this.variableResolver = variableResolver; | |
} | |
// 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; | |
} | |
/** | |
* 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 | |
*/ | |
public void setEnableSubstitutionInVariables( | |
final boolean enableSubstitutionInVariables) { | |
this.enableSubstitutionInVariables = enableSubstitutionInVariables; | |
} | |
/** | |
* 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 | |
* | |
* @since 1.2 | |
*/ | |
public boolean isDisableSubstitutionInValues() { | |
return disableSubstitutionInValues; | |
} | |
/** | |
* Sets a flag whether substitution is done in variable values (recursive). | |
* | |
* @param disableSubstitutionInValues true if substitution in variable value are disabled | |
* | |
* @since 1.2 | |
*/ | |
public void setDisableSubstitutionInValues(final boolean disableSubstitutionInValues) { | |
this.disableSubstitutionInValues = disableSubstitutionInValues; | |
} | |
/** | |
* Returns the flag controlling whether escapes are preserved during | |
* substitution. | |
* | |
* @return the preserve escape flag | |
*/ | |
public boolean isPreserveEscapes() { | |
return preserveEscapes; | |
} | |
/** | |
* 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 | |
*/ | |
public void setPreserveEscapes(final boolean preserveEscapes) { | |
this.preserveEscapes = preserveEscapes; | |
} | |
} |