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| 1 | /* | ||
| 2 | * Copyright (c) 2008, 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. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle in the LICENSE file that accompanied this code. | ||
| 10 | * | ||
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | ||
| 14 | * version 2 for more details (a copy is included in the LICENSE file that | ||
| 15 | * accompanied this code). | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU General Public License version | ||
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, | ||
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 20 | * | ||
| 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | package com.sun.beans.decoder; | ||
| 26 | |||
| 27 | import com.sun.beans.finder.ConstructorFinder; | ||
| 28 | |||
| 29 | import java.lang.reflect.Array; | ||
| 30 | import java.lang.reflect.Constructor; | ||
| 31 | |||
| 32 | import java.util.ArrayList; | ||
| 33 | import java.util.List; | ||
| 34 | |||
| 35 | /** | ||
| 36 | * This class is intended to handle <new> element. | ||
| 37 | * It describes instantiation of the object. | ||
| 38 | * The {@code class} attribute denotes | ||
| 39 | * the name of the class to instantiate. | ||
| 40 | * The inner elements specifies the arguments of the constructor. | ||
| 41 | * For example:<pre> | ||
| 42 | * <new class="java.lang.Long"> | ||
| 43 | * <string>10</string> | ||
| 44 | * </new></pre> | ||
| 45 | * is equivalent to {@code new Long("10")} in Java code. | ||
| 46 | * <p>The following atributes are supported: | ||
| 47 | * <dl> | ||
| 48 | * <dt>class | ||
| 49 | * <dd>the type of object for instantiation | ||
| 50 | * <dt>id | ||
| 51 | * <dd>the identifier of the variable that is intended to store the result | ||
| 52 | * </dl> | ||
| 53 | * | ||
| 54 | * @since 1.7 | ||
| 55 | * | ||
| 56 | * @author Sergey A. Malenkov | ||
| 57 | */ | ||
| 58 | class NewElementHandler extends ElementHandler { | ||
| 59 | private List<Object> arguments = new ArrayList<Object>(); | ||
| 60 | private ValueObject value = ValueObjectImpl.VOID; | ||
| 61 | |||
| 62 | private Class<?> type; | ||
| 63 | |||
| 64 | /** | ||
| 65 | * Parses attributes of the element. | ||
| 66 | * The following atributes are supported: | ||
| 67 | * <dl> | ||
| 68 | * <dt>class | ||
| 69 | * <dd>the type of object for instantiation | ||
| 70 | * <dt>id | ||
| 71 | * <dd>the identifier of the variable that is intended to store the result | ||
| 72 | * </dl> | ||
| 73 | * | ||
| 74 | * @param name the attribute name | ||
| 75 | * @param value the attribute value | ||
| 76 | */ | ||
| 77 | @Override | ||
| 78 | public void addAttribute(String name, String value) { | ||
| 79 | if (name.equals("class")) { // NON-NLS: the attribute name | ||
| 80 | this.type = getOwner().findClass(value); | ||
| 81 | } else { | ||
| 82 | super.addAttribute(name, value); | ||
| 83 | } | ||
| 84 | } | ||
| 85 | |||
| 86 | /** | ||
| 87 | * Adds the argument to the list of arguments | ||
| 88 | * that is used to calculate the value of this element. | ||
| 89 | * | ||
| 90 | * @param argument the value of the element that contained in this one | ||
| 91 | */ | ||
| 92 | @Override | ||
| 93 | protected final void addArgument(Object argument) { | ||
| 94 | if (this.arguments == null) { | ||
| 95 | throw new IllegalStateException("Could not add argument to evaluated element"); | ||
| 96 | } | ||
| 97 | this.arguments.add(argument); | ||
| 98 | } | ||
| 99 | |||
| 100 | /** | ||
| 101 | * Returns the context of the method. | ||
| 102 | * The context of the static method is the class object. | ||
| 103 | * The context of the non-static method is the value of the parent element. | ||
| 104 | * | ||
| 105 | * @return the context of the method | ||
| 106 | */ | ||
| 107 | @Override | ||
| 108 | protected final Object getContextBean() { | ||
| 109 | return (this.type != null) | ||
| 110 | ? this.type | ||
| 111 | : super.getContextBean(); | ||
| 112 | } | ||
| 113 | |||
| 114 | /** | ||
| 115 | * Returns the value of this element. | ||
| 116 | * | ||
| 117 | * @return the value of this element | ||
| 118 | */ | ||
| 119 | @Override | ||
| 120 | protected final ValueObject getValueObject() { | ||
| 121 | if (this.arguments != null) { | ||
| 122 | try { | ||
| 123 | this.value = getValueObject(this.type, this.arguments.toArray()); | ||
| 124 | } | ||
| 125 | catch (Exception exception) { | ||
| 126 | getOwner().handleException(exception); | ||
| 127 | } | ||
| 128 | finally { | ||
| 129 | this.arguments = null; | ||
| 130 | } | ||
| 131 | } | ||
| 132 | return this.value; | ||
| 133 | } | ||
| 134 | |||
| 135 | /** | ||
| 136 | * Calculates the value of this element | ||
| 137 | * using the base class and the array of arguments. | ||
| 138 | * By default, it creates an instance of the base class. | ||
| 139 | * This method should be overridden in those handlers | ||
| 140 | * that extend behavior of this element. | ||
| 141 | * | ||
| 142 | * @param type the base class | ||
| 143 | * @param args the array of arguments | ||
| 144 | * @return the value of this element | ||
| 145 | * @throws Exception if calculation is failed | ||
| 146 | */ | ||
| 147 | ValueObject getValueObject(Class<?> type, Object[] args) throws Exception { | ||
| 148 | if (type == null) { | ||
| 149 | throw new IllegalArgumentException("Class name is not set"); | ||
| 150 | } | ||
| 151 | Class<?>[] types = getArgumentTypes(args); | ||
| 152 | Constructor<?> constructor = ConstructorFinder.findConstructor(type, types); | ||
| 153 | if (constructor.isVarArgs()) { | ||
| 154 | args = getArguments(args, constructor.getParameterTypes()); | ||
| 155 | } | ||
| 156 | return ValueObjectImpl.create(constructor.newInstance(args)); | ||
| 157 | } | ||
| 158 | |||
| 159 | /** | ||
| 160 | * Converts the array of arguments to the array of corresponding classes. | ||
| 161 | * If argument is {@code null} the class is {@code null} too. | ||
| 162 | * | ||
| 163 | * @param arguments the array of arguments | ||
| 164 | * @return the array of corresponding classes | ||
| 165 | */ | ||
| 166 | static Class<?>[] getArgumentTypes(Object[] arguments) { | ||
| 167 | Class<?>[] types = new Class<?>[arguments.length]; | ||
| 168 | for (int i = 0; i < arguments.length; i++) { | ||
| 169 | if (arguments[i] != null) { | ||
| 170 | types[i] = arguments[i].getClass(); | ||
| 171 | } | ||
| 172 | } | ||
| 173 | return types; | ||
| 174 | } | ||
| 175 | |||
| 176 | /** | ||
| 177 | * Resolves variable arguments. | ||
| 178 | * | ||
| 179 | * @param arguments the array of arguments | ||
| 180 | * @param types the array of parameter types | ||
| 181 | * @return the resolved array of arguments | ||
| 182 | */ | ||
| 183 | static Object[] getArguments(Object[] arguments, Class<?>[] types) { | ||
| 184 | int index = types.length - 1; | ||
| 185 | if (types.length == arguments.length) { | ||
| 186 | Object argument = arguments[index]; | ||
| 187 | if (argument == null) { | ||
| 188 | return arguments; | ||
| 189 | } | ||
| 190 | Class<?> type = types[index]; | ||
| 191 | if (type.isAssignableFrom(argument.getClass())) { | ||
| 192 | return arguments; | ||
| 193 | } | ||
| 194 | } | ||
| 195 | int length = arguments.length - index; | ||
| 196 | Class<?> type = types[index].getComponentType(); | ||
| 197 | Object array = Array.newInstance(type, length); | ||
| 198 | System.arraycopy(arguments, index, array, 0, length); | ||
| 199 | |||
| 200 | Object[] args = new Object[types.length]; | ||
| 201 | System.arraycopy(arguments, 0, args, 0, index); | ||
| 202 | args[index] = array; | ||
| 203 | return args; | ||
| 204 | } | ||
| 205 | } | ||