1 package org.apache.commons.digester3.examples.plugins.pipeline; 2 3 /* 4 * Licensed to the Apache Software Foundation (ASF) under one or more 5 * contributor license agreements. See the NOTICE file distributed with 6 * this work for additional information regarding copyright ownership. 7 * The ASF licenses this file to You under the Apache License, Version 2.0 8 * (the "License"); you may not use this file except in compliance with 9 * the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, software 14 * distributed under the License is distributed on an "AS IS" BASIS, 15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 * See the License for the specific language governing permissions and 17 * limitations under the License. 18 */ 19 20 import org.apache.commons.digester3.Digester; 21 22 /** 23 * An implementation of the Transform interface which replaces all occurrences 24 * of a specified string with a different string. 25 * <p> 26 * Because this class wishes to configure instances via nested "from" and 27 * "to" tags, it needs to define an addRules method to add rules to the 28 * Digester dynamically. Note that there are different ways of defining the 29 * rules though; for example they can be defined in a separate 30 * SubstituteTransformRuleInfo class. 31 */ 32 public class SubstituteTransform 33 implements Transform 34 { 35 36 private String from; 37 38 private String to; 39 40 public void setFrom( String from ) 41 { 42 this.from = from; 43 } 44 45 public void setTo( String to ) 46 { 47 this.to = to; 48 } 49 50 public String transform( String s ) 51 { 52 StringBuilder buf = new StringBuilder( s ); 53 while ( true ) 54 { 55 int idx = buf.indexOf( from ); 56 if ( idx == -1 ) 57 { 58 break; 59 } 60 61 buf.replace( idx, idx + from.length(), to ); 62 } 63 return buf.toString(); 64 } 65 66 public static void addRules( Digester d, String patternPrefix ) 67 { 68 d.addCallMethod( patternPrefix + "/from", "setFrom", 0 ); 69 d.addCallMethod( patternPrefix + "/to", "setTo", 0 ); 70 } 71 72 }