| /* |
| * 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.lang.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; |
| |
| /** |
| * 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> |
| * 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>. |
| * |
| * @author Apache Software Foundation |
| * @author Oliver Heger |
| * @version $Id$ |
| * @since 2.2 |
| */ |
| 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("}"); |
| |
| /** |
| * Stores the escape character. |
| */ |
| private char escapeChar; |
| /** |
| * Stores the variable prefix. |
| */ |
| private StrMatcher prefixMatcher; |
| /** |
| * Stores the variable suffix. |
| */ |
| private StrMatcher suffixMatcher; |
| /** |
| * Variable resolution is delegated to an implementor of VariableResolver. |
| */ |
| private StrLookup variableResolver; |
| /** |
| * The flag whether substitution in variable names is enabled. |
| */ |
| private boolean enableSubstitutionInVariables; |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Replaces all the occurrences of variables in the given source object with |
| * their matching values from 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 String replace(Object source, Map 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 specifiy a |
| * custom variable prefix and suffix |
| * |
| * @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 String replace(Object source, Map valueMap, String prefix, 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 |
| * @since 2.6 |
| */ |
| public static String replace(Object source, Properties valueProperties) |
| { |
| if (valueProperties == null) { |
| return source.toString(); |
| } |
| Map valueMap = new HashMap(); |
| Enumeration propNames = valueProperties.propertyNames(); |
| while (propNames.hasMoreElements()) |
| { |
| String propName = (String)propNames.nextElement(); |
| 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(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 valueMap the map with the variables' values, may be null |
| */ |
| public StrSubstitutor(Map valueMap) { |
| this(StrLookup.mapLookup(valueMap), DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_ESCAPE); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. Uses a default escaping character. |
| * |
| * @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 StrSubstitutor(Map valueMap, String prefix, String suffix) { |
| this(StrLookup.mapLookup(valueMap), prefix, suffix, DEFAULT_ESCAPE); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. |
| * |
| * @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 StrSubstitutor(Map valueMap, String prefix, String suffix, char escape) { |
| this(StrLookup.mapLookup(valueMap), prefix, suffix, escape); |
| } |
| |
| /** |
| * Creates a new instance and initializes it. |
| * |
| * @param variableResolver the variable resolver, may be null |
| */ |
| public StrSubstitutor(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(StrLookup variableResolver, String prefix, String suffix, char escape) { |
| this.setVariableResolver(variableResolver); |
| this.setVariablePrefix(prefix); |
| this.setVariableSuffix(suffix); |
| this.setEscapeChar(escape); |
| } |
| |
| /** |
| * 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( |
| StrLookup variableResolver, StrMatcher prefixMatcher, StrMatcher suffixMatcher, char escape) { |
| this.setVariableResolver(variableResolver); |
| this.setVariablePrefixMatcher(prefixMatcher); |
| this.setVariableSuffixMatcher(suffixMatcher); |
| this.setEscapeChar(escape); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * 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(String source) { |
| if (source == null) { |
| return null; |
| } |
| StrBuilder buf = new StrBuilder(source); |
| if (substitute(buf, 0, source.length()) == false) { |
| 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(String source, int offset, int length) { |
| if (source == null) { |
| return null; |
| } |
| StrBuilder buf = new StrBuilder(length).append(source, offset, length); |
| if (substitute(buf, 0, length) == false) { |
| 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(char[] source) { |
| if (source == null) { |
| return null; |
| } |
| 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(char[] source, int offset, int length) { |
| if (source == null) { |
| return null; |
| } |
| 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(StringBuffer source) { |
| if (source == null) { |
| return null; |
| } |
| 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(StringBuffer source, int offset, int length) { |
| if (source == null) { |
| return null; |
| } |
| 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(StrBuilder source) { |
| if (source == null) { |
| return null; |
| } |
| 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(StrBuilder source, int offset, int length) { |
| if (source == null) { |
| return null; |
| } |
| 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(Object source) { |
| if (source == null) { |
| return null; |
| } |
| 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(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(StringBuffer source, int offset, int length) { |
| if (source == null) { |
| return false; |
| } |
| StrBuilder buf = new StrBuilder(length).append(source, offset, length); |
| if (substitute(buf, 0, length) == false) { |
| 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(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(StrBuilder source, int offset, 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(StrBuilder buf, int offset, 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(StrBuilder buf, int offset, int length, List priorVariables) { |
| StrMatcher prefixMatcher = getVariablePrefixMatcher(); |
| StrMatcher suffixMatcher = getVariableSuffixMatcher(); |
| char escape = getEscapeChar(); |
| |
| boolean top = (priorVariables == null); |
| boolean altered = false; |
| int lengthChange = 0; |
| char[] chars = buf.buffer; |
| int bufEnd = offset + length; |
| int pos = offset; |
| while (pos < bufEnd) { |
| int startMatchLen = prefixMatcher.isMatch(chars, pos, offset, |
| bufEnd); |
| if (startMatchLen == 0) { |
| pos++; |
| } else { |
| // found variable start marker |
| if (pos > offset && chars[pos - 1] == escape) { |
| // escaped |
| buf.deleteCharAt(pos - 1); |
| chars = buf.buffer; // in case buffer was altered |
| lengthChange--; |
| altered = true; |
| bufEnd--; |
| } else { |
| // find suffix |
| int startPos = pos; |
| pos += startMatchLen; |
| int endMatchLen = 0; |
| int nestedVarCount = 0; |
| while (pos < bufEnd) { |
| if (isEnableSubstitutionInVariables() |
| && (endMatchLen = prefixMatcher.isMatch(chars, |
| pos, offset, bufEnd)) != 0) { |
| // found a nested variable start |
| nestedVarCount++; |
| pos += endMatchLen; |
| continue; |
| } |
| |
| endMatchLen = suffixMatcher.isMatch(chars, pos, offset, |
| bufEnd); |
| if (endMatchLen == 0) { |
| pos++; |
| } else { |
| // found variable end marker |
| if (nestedVarCount == 0) { |
| String varName = new String(chars, startPos |
| + startMatchLen, pos - startPos |
| - startMatchLen); |
| if (isEnableSubstitutionInVariables()) { |
| StrBuilder bufName = new StrBuilder(varName); |
| substitute(bufName, 0, bufName.length()); |
| varName = bufName.toString(); |
| } |
| pos += endMatchLen; |
| int endPos = pos; |
| |
| // 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) { |
| // recursive replace |
| int varLen = varValue.length(); |
| buf.replace(startPos, endPos, varValue); |
| altered = true; |
| int 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; |
| } else { |
| 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(String varName, List priorVariables) { |
| if (priorVariables.contains(varName) == false) { |
| return; |
| } |
| 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(String variableName, StrBuilder buf, int startPos, int endPos) { |
| 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(char escapeCharacter) { |
| this.escapeChar = escapeCharacter; |
| } |
| |
| // Prefix |
| //----------------------------------------------------------------------- |
| /** |
| * Gets the variable prefix matcher currently in use. |
| * <p> |
| * The variable prefix is the characer 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 characer 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(StrMatcher prefixMatcher) { |
| if (prefixMatcher == null) { |
| throw new IllegalArgumentException("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(char prefix) { |
| return setVariablePrefixMatcher(StrMatcher.charMatcher(prefix)); |
| } |
| |
| /** |
| * Sets the variable prefix to use. |
| * <p> |
| * The variable prefix is the characer 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(String prefix) { |
| if (prefix == null) { |
| throw new IllegalArgumentException("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 characer 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 characer 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(StrMatcher suffixMatcher) { |
| if (suffixMatcher == null) { |
| throw new IllegalArgumentException("Variable suffix matcher must not be null!"); |
| } |
| this.suffixMatcher = suffixMatcher; |
| return this; |
| } |
| |
| /** |
| * Sets the variable suffix to use. |
| * <p> |
| * The variable suffix is the characer 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(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(String suffix) { |
| if (suffix == null) { |
| throw new IllegalArgumentException("Variable suffix must not be null!"); |
| } |
| return setVariableSuffixMatcher(StrMatcher.stringMatcher(suffix)); |
| } |
| |
| // 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(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 |
| * @since 2.6 |
| */ |
| 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 |
| * @since 2.6 |
| */ |
| public void setEnableSubstitutionInVariables( |
| boolean enableSubstitutionInVariables) { |
| this.enableSubstitutionInVariables = enableSubstitutionInVariables; |
| } |
| } |