1// 2// ======================================================================== 3// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd. 4// ------------------------------------------------------------------------ 5// All rights reserved. This program and the accompanying materials 6// are made available under the terms of the Eclipse Public License v1.0 7// and Apache License v2.0 which accompanies this distribution. 8// 9// The Eclipse Public License is available at 10// http://www.eclipse.org/legal/epl-v10.html 11// 12// The Apache License v2.0 is available at 13// http://www.opensource.org/licenses/apache2.0.php 14// 15// You may elect to redistribute this code under either of these licenses. 16// ======================================================================== 17// 18 19package org.eclipse.jetty.util; 20 21import java.io.File; 22import java.net.URL; 23import java.net.URLClassLoader; 24import java.util.Locale; 25import java.util.MissingResourceException; 26import java.util.ResourceBundle; 27 28import org.eclipse.jetty.util.resource.Resource; 29 30/* ------------------------------------------------------------ */ 31/** ClassLoader Helper. 32 * This helper class allows classes to be loaded either from the 33 * Thread's ContextClassLoader, the classloader of the derived class 34 * or the system ClassLoader. 35 * 36 * <B>Usage:</B><PRE> 37 * public class MyClass { 38 * void myMethod() { 39 * ... 40 * Class c=Loader.loadClass(this.getClass(),classname); 41 * ... 42 * } 43 * </PRE> 44 * 45 */ 46public class Loader 47{ 48 /* ------------------------------------------------------------ */ 49 public static URL getResource(Class<?> loadClass,String name, boolean checkParents) 50 { 51 URL url =null; 52 ClassLoader loader=Thread.currentThread().getContextClassLoader(); 53 while (url==null && loader!=null ) 54 { 55 url=loader.getResource(name); 56 loader=(url==null&&checkParents)?loader.getParent():null; 57 } 58 59 loader=loadClass==null?null:loadClass.getClassLoader(); 60 while (url==null && loader!=null ) 61 { 62 url=loader.getResource(name); 63 loader=(url==null&&checkParents)?loader.getParent():null; 64 } 65 66 if (url==null) 67 { 68 url=ClassLoader.getSystemResource(name); 69 } 70 71 return url; 72 } 73 74 /* ------------------------------------------------------------ */ 75 @SuppressWarnings("rawtypes") 76 public static Class loadClass(Class loadClass,String name) 77 throws ClassNotFoundException 78 { 79 return loadClass(loadClass,name,false); 80 } 81 82 /* ------------------------------------------------------------ */ 83 /** Load a class. 84 * 85 * @param loadClass 86 * @param name 87 * @param checkParents If true, try loading directly from parent classloaders. 88 * @return Class 89 * @throws ClassNotFoundException 90 */ 91 @SuppressWarnings("rawtypes") 92 public static Class loadClass(Class loadClass,String name,boolean checkParents) 93 throws ClassNotFoundException 94 { 95 ClassNotFoundException ex=null; 96 Class<?> c =null; 97 ClassLoader loader=Thread.currentThread().getContextClassLoader(); 98 while (c==null && loader!=null ) 99 { 100 try { c=loader.loadClass(name); } 101 catch (ClassNotFoundException e) {if(ex==null)ex=e;} 102 loader=(c==null&&checkParents)?loader.getParent():null; 103 } 104 105 loader=loadClass==null?null:loadClass.getClassLoader(); 106 while (c==null && loader!=null ) 107 { 108 try { c=loader.loadClass(name); } 109 catch (ClassNotFoundException e) {if(ex==null)ex=e;} 110 loader=(c==null&&checkParents)?loader.getParent():null; 111 } 112 113 if (c==null) 114 { 115 try { c=Class.forName(name); } 116 catch (ClassNotFoundException e) {if(ex==null)ex=e;} 117 } 118 119 if (c!=null) 120 return c; 121 throw ex; 122 } 123 124 125 126 /* ------------------------------------------------------------ */ 127 public static ResourceBundle getResourceBundle(Class<?> loadClass,String name,boolean checkParents, Locale locale) 128 throws MissingResourceException 129 { 130 MissingResourceException ex=null; 131 ResourceBundle bundle =null; 132 ClassLoader loader=Thread.currentThread().getContextClassLoader(); 133 while (bundle==null && loader!=null ) 134 { 135 try { bundle=ResourceBundle.getBundle(name, locale, loader); } 136 catch (MissingResourceException e) {if(ex==null)ex=e;} 137 loader=(bundle==null&&checkParents)?loader.getParent():null; 138 } 139 140 loader=loadClass==null?null:loadClass.getClassLoader(); 141 while (bundle==null && loader!=null ) 142 { 143 try { bundle=ResourceBundle.getBundle(name, locale, loader); } 144 catch (MissingResourceException e) {if(ex==null)ex=e;} 145 loader=(bundle==null&&checkParents)?loader.getParent():null; 146 } 147 148 if (bundle==null) 149 { 150 try { bundle=ResourceBundle.getBundle(name, locale); } 151 catch (MissingResourceException e) {if(ex==null)ex=e;} 152 } 153 154 if (bundle!=null) 155 return bundle; 156 throw ex; 157 } 158 159 160 /* ------------------------------------------------------------ */ 161 /** 162 * Generate the classpath (as a string) of all classloaders 163 * above the given classloader. 164 * 165 * This is primarily used for jasper. 166 * @return the system class path 167 */ 168 public static String getClassPath(ClassLoader loader) throws Exception 169 { 170 StringBuilder classpath=new StringBuilder(); 171 while (loader != null && (loader instanceof URLClassLoader)) 172 { 173 URL[] urls = ((URLClassLoader)loader).getURLs(); 174 if (urls != null) 175 { 176 for (int i=0;i<urls.length;i++) 177 { 178 Resource resource = Resource.newResource(urls[i]); 179 File file=resource.getFile(); 180 if (file!=null && file.exists()) 181 { 182 if (classpath.length()>0) 183 classpath.append(File.pathSeparatorChar); 184 classpath.append(file.getAbsolutePath()); 185 } 186 } 187 } 188 loader = loader.getParent(); 189 } 190 return classpath.toString(); 191 } 192} 193 194