1 /* 2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 package jdk.test.lib.combo; 25 26 import java.util.regex.Matcher; 27 import java.util.regex.Pattern; 28 29 /** 30 * A combo parameter represents an 'hole' in a template that can be replaced with a given string. 31 * The schema of such holes is defined in {@link ComboParameter#pattern}; the main routine for 32 * replacing holes in a template scheme is {@link ComboParameter#expandTemplate(String, Resolver)}. 33 */ 34 public interface ComboParameter { 35 36 /** 37 * A combo parameter can take the form: 38 * <p> 39 * #{MAJOR} 40 * #{MAJOR.} 41 * #{MAJOR.MINOR} 42 * <p> 43 * where MAJOR can be IDENTIFIER or IDENTIFIER[NUMERIC_INDEX] 44 * and MINOR can be an identifier. 45 */ 46 Pattern pattern = Pattern.compile("#\\{([A-Z_][A-Z0-9_]*(?:\\[\\d+\\])?)(?:\\.([A-Z0-9_]*))?\\}"); 47 48 /** 49 * Entry point for the customizable replacement logic. Subclasses must implement this method to 50 * specify how a given template hole should be expanded. An optional contextual argument is passed 51 * in as parameter, to make expansion more flexible. 52 */ 53 String expand(String optParameter); 54 55 /** 56 * Helper class for defining 'constant' combo parameters - i.e. parameters that always expand 57 * as a given string value - regardless of the context. 58 */ 59 class Constant<D> implements ComboParameter { 60 61 D data; 62 63 public Constant(D data) { 64 this.data = data; 65 } 66 67 @Override 68 public String expand(String _unused) { 69 return String.valueOf(data); 70 } 71 } 72 73 /** 74 * Helper interface used to lookup parameters given a parameter name. 75 */ 76 interface Resolver { 77 ComboParameter lookup(String name); 78 } 79 80 /** 81 * Main routine for replacing holes in a template string. Holes are repeatedly searches, their 82 * corresponding parameters retrieved, and replaced through expansion; since an expansion can 83 * lead to more holes, the process has to be applied until a fixed point is reached. 84 */ 85 static String expandTemplate(String template, Resolver resolver) { 86 CharSequence in = template; 87 StringBuffer out = new StringBuffer(); 88 while (true) { 89 boolean more = false; 90 Matcher m = pattern.matcher(in); 91 while (m.find()) { 92 String parameterName = m.group(1); 93 String minor = m.group(2); 94 ComboParameter parameter = resolver.lookup(parameterName); 95 if (parameter == null) { 96 throw new IllegalStateException("Unhandled parameter name " + parameterName); 97 } 98 99 String replacement = parameter.expand(minor); 100 more |= pattern.matcher(replacement).find(); 101 m.appendReplacement(out, replacement); 102 } 103 m.appendTail(out); 104 if (!more) 105 return out.toString(); 106 else { 107 in = out; 108 out = new StringBuffer(); 109 } 110 } 111 } 112 }