1/* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package java.lang; 18 19import java.net.MalformedURLException; 20import java.net.URL; 21import java.security.ProtectionDomain; 22import java.util.ArrayList; 23import java.util.Enumeration; 24import java.util.NoSuchElementException; 25 26class VMClassLoader { 27 28 /** 29 * Get a resource from a file in the bootstrap class path. 30 * 31 * It would be simpler to just walk through the class path elements 32 * ourselves, but that would require reopening Jar files. 33 * 34 * We assume that the bootclasspath can't change once the VM has 35 * started. This assumption seems to be supported by the spec. 36 */ 37 static URL getResource(String name) { 38 int numEntries = getBootClassPathSize(); 39 int i; 40 41 for (i = 0; i < numEntries; i++) { 42 String urlStr = getBootClassPathResource(name, i); 43 if (urlStr != null) { 44 try { 45 return new URL(urlStr); 46 } 47 catch (MalformedURLException mue) { 48 mue.printStackTrace(); 49 // unexpected; keep going 50 } 51 } 52 } 53 54 return null; 55 } 56 57 /* 58 * Get an enumeration with all matching resources. 59 */ 60 static Enumeration<URL> getResources(String name) { 61 ArrayList<URL> list = null; 62 int numEntries = getBootClassPathSize(); 63 int i; 64 65 for (i = 0; i < numEntries; i++) { 66 String urlStr = getBootClassPathResource(name, i); 67 if (urlStr != null) { 68 if (list == null) 69 list = new ArrayList<URL>(); 70 71 try { 72 list.add(new URL(urlStr)); 73 } 74 catch (MalformedURLException mue) { 75 mue.printStackTrace(); 76 // unexpected; keep going 77 } 78 } 79 } 80 81 if (list == null) 82 return null; 83 else 84 return new EnumerateListArray<URL>(list); 85 } 86 87 /** 88 * Load class with bootstrap class loader. 89 */ 90 native static Class loadClass(String name, boolean resolve) 91 throws ClassNotFoundException; 92 93 native static Class getPrimitiveClass(char type); 94 95 /* 96 * TODO(Google) Ticket 156: Native implementation does nothing, just throws 97 * OperationNotSupportedException. 98 */ 99 native static Class defineClass(ClassLoader cl, String name, 100 byte[] data, int offset, int len, ProtectionDomain pd) 101 throws ClassFormatError; 102 103 /* 104 * TODO(Google) Ticket 156: Native implementation does nothing, just throws 105 * OperationNotSupportedException. 106 */ 107 native static Class defineClass(ClassLoader cl, 108 byte[] data, int offset, int len, ProtectionDomain pd) 109 throws ClassFormatError; 110 111 native static Class findLoadedClass(ClassLoader cl, String name); 112 113 /** 114 * Boot class path manipulation, for getResources(). 115 */ 116 native private static int getBootClassPathSize(); 117 native private static String getBootClassPathResource(String name, 118 int index); 119 120 /* 121 * Create an Enumeration for an ArrayList. 122 */ 123 private static class EnumerateListArray<T> implements Enumeration<T> { 124 private final ArrayList mList; 125 private int i = 0; 126 127 EnumerateListArray(ArrayList list) { 128 mList = list; 129 } 130 131 public boolean hasMoreElements() { 132 return i < mList.size(); 133 } 134 135 public T nextElement() { 136 if (i >= mList.size()) 137 throw new NoSuchElementException(); 138 return (T) mList.get(i++); 139 } 140 }; 141} 142 143