| 1 | /* |
| 2 | * Copyright 2002-2008 the original author or authors. |
| 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 | |
| 17 | /* |
| 18 | * Copyright 2002-2008 the original author or authors. |
| 19 | * |
| 20 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 21 | * you may not use this file except in compliance with the License. |
| 22 | * You may obtain a copy of the License at |
| 23 | * |
| 24 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 25 | * |
| 26 | * Unless required by applicable law or agreed to in writing, software |
| 27 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 28 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 29 | * See the License for the specific language governing permissions and |
| 30 | * limitations under the License. |
| 31 | */ |
| 32 | package org.springframework.batch.support; |
| 33 | |
| 34 | import java.lang.reflect.Method; |
| 35 | import java.util.Arrays; |
| 36 | |
| 37 | import org.springframework.aop.framework.Advised; |
| 38 | import org.springframework.util.Assert; |
| 39 | import org.springframework.util.ClassUtils; |
| 40 | |
| 41 | /** |
| 42 | * Simple implementation of the {@link MethodInvoker} interface that invokes a |
| 43 | * method on an object. If the method has no arguments, but arguments are |
| 44 | * provided, they are ignored and the method is invoked anyway. If there are |
| 45 | * more arguments than there are provided, then an exception is thrown. |
| 46 | * |
| 47 | * @author Lucas Ward |
| 48 | * @since 2.0 |
| 49 | */ |
| 50 | public class SimpleMethodInvoker implements MethodInvoker { |
| 51 | |
| 52 | private final Object object; |
| 53 | |
| 54 | private Method method; |
| 55 | |
| 56 | public SimpleMethodInvoker(Object object, Method method) { |
| 57 | Assert.notNull(object, "Object to invoke must not be null"); |
| 58 | Assert.notNull(method, "Method to invoke must not be null"); |
| 59 | this.method = method; |
| 60 | this.object = object; |
| 61 | } |
| 62 | |
| 63 | public SimpleMethodInvoker(Object object, String methodName, Class<?>... paramTypes) { |
| 64 | Assert.notNull(object, "Object to invoke must not be null"); |
| 65 | this.method = ClassUtils.getMethodIfAvailable(object.getClass(), methodName, paramTypes); |
| 66 | if (this.method == null) { |
| 67 | // try with no params |
| 68 | this.method = ClassUtils.getMethodIfAvailable(object.getClass(), methodName, new Class[] {}); |
| 69 | } |
| 70 | if (this.method == null) { |
| 71 | throw new IllegalArgumentException("No methods found for name: [" + methodName + "] in class: [" |
| 72 | + object.getClass() + "] with arguments of type: [" + Arrays.toString(paramTypes) + "]"); |
| 73 | } |
| 74 | this.object = object; |
| 75 | } |
| 76 | |
| 77 | /* |
| 78 | * (non-Javadoc) |
| 79 | * |
| 80 | * @see |
| 81 | * org.springframework.batch.core.configuration.util.MethodInvoker#invokeMethod |
| 82 | * (java.lang.Object[]) |
| 83 | */ |
| 84 | @Override |
| 85 | public Object invokeMethod(Object... args) { |
| 86 | |
| 87 | Class<?>[] parameterTypes = method.getParameterTypes(); |
| 88 | Object[] invokeArgs; |
| 89 | if (parameterTypes.length == 0) { |
| 90 | invokeArgs = new Object[] {}; |
| 91 | } |
| 92 | else if (parameterTypes.length != args.length) { |
| 93 | throw new IllegalArgumentException("Wrong number of arguments, expected no more than: [" |
| 94 | + parameterTypes.length + "]"); |
| 95 | } |
| 96 | else { |
| 97 | invokeArgs = args; |
| 98 | } |
| 99 | |
| 100 | method.setAccessible(true); |
| 101 | |
| 102 | try { |
| 103 | // Extract the target from an Advised as late as possible |
| 104 | // in case it contains a lazy initialization |
| 105 | Object target = extractTarget(object, method); |
| 106 | return method.invoke(target, invokeArgs); |
| 107 | } |
| 108 | catch (Exception e) { |
| 109 | throw new IllegalArgumentException("Unable to invoke method: [" + method + "] on object: [" + object |
| 110 | + "] with arguments: [" + Arrays.toString(args) + "]", e); |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | private Object extractTarget(Object target, Method method) { |
| 115 | if (target instanceof Advised) { |
| 116 | Object source; |
| 117 | try { |
| 118 | source = ((Advised) target).getTargetSource().getTarget(); |
| 119 | } |
| 120 | catch (Exception e) { |
| 121 | throw new IllegalStateException("Could not extract target from proxy", e); |
| 122 | } |
| 123 | if (source instanceof Advised) { |
| 124 | source = extractTarget(source, method); |
| 125 | } |
| 126 | if (method.getDeclaringClass().isAssignableFrom(source.getClass())) { |
| 127 | target = source; |
| 128 | } |
| 129 | } |
| 130 | return target; |
| 131 | } |
| 132 | |
| 133 | @Override |
| 134 | public boolean equals(Object obj) { |
| 135 | if (!(obj instanceof SimpleMethodInvoker)) { |
| 136 | return false; |
| 137 | } |
| 138 | |
| 139 | if (obj == this) { |
| 140 | return true; |
| 141 | } |
| 142 | SimpleMethodInvoker rhs = (SimpleMethodInvoker) obj; |
| 143 | return (rhs.method.equals(this.method)) && (rhs.object.equals(this.object)); |
| 144 | } |
| 145 | |
| 146 | @Override |
| 147 | public int hashCode() { |
| 148 | int result = 25; |
| 149 | result = 31 * result + object.hashCode(); |
| 150 | result = 31 * result + method.hashCode(); |
| 151 | return result; |
| 152 | } |
| 153 | } |