diff options
Diffstat (limited to 'framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/util/ReflectUtil.java')
| -rw-r--r-- | framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/util/ReflectUtil.java | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/util/ReflectUtil.java b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/util/ReflectUtil.java new file mode 100644 index 00000000..88b7911e --- /dev/null +++ b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/util/ReflectUtil.java @@ -0,0 +1,212 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + */ +package org.apache.tools.ant.util; + +import java.lang.reflect.Constructor; +import java.lang.reflect.Field; +import java.lang.reflect.InvocationTargetException; +import java.lang.reflect.Method; + +import org.apache.tools.ant.BuildException; + +/** + * Utility class to handle reflection on java objects. + * The class contains static methods to call reflection + * methods, catch any exceptions, converting them + * to BuildExceptions. + */ +// CheckStyle:FinalClassCheck OFF - backward compatible +public class ReflectUtil { + + /** private constructor */ + private ReflectUtil() { + } + + /** + * Create an instance of a class using the constructor matching + * the given arguments. + * @since Ant 1.8.0 + */ + public static <T> T newInstance(Class<T> ofClass, + Class<?>[] argTypes, + Object[] args) { + try { + Constructor<T> con = ofClass.getConstructor(argTypes); + return con.newInstance(args); + } catch (Exception t) { + throwBuildException(t); + return null; // NotReached + } + } + + /** + * Call a method on the object with no parameters. + * @param obj the object to invoke the method on. + * @param methodName the name of the method to call + * @return the object returned by the method + */ + public static Object invoke(Object obj, String methodName) { + try { + Method method; + method = obj.getClass().getMethod( + methodName, (Class[]) null); + return method.invoke(obj, (Object[]) null); + } catch (Exception t) { + throwBuildException(t); + return null; // NotReached + } + } + + /** + * Call a method on the object with no parameters. + * Note: Unlike the invoke method above, this + * calls class or static methods, not instance methods. + * @param obj the object to invoke the method on. + * @param methodName the name of the method to call + * @return the object returned by the method + */ + public static Object invokeStatic(Object obj, String methodName) { + try { + Method method; + method = ((Class<?>) obj).getMethod( + methodName, (Class[]) null); + return method.invoke(obj, (Object[]) null); + } catch (Exception t) { + throwBuildException(t); + return null; // NotReached + } + } + + /** + * Call a method on the object with one argument. + * @param obj the object to invoke the method on. + * @param methodName the name of the method to call + * @param argType the type of argument. + * @param arg the value of the argument. + * @return the object returned by the method + */ + public static Object invoke( + Object obj, String methodName, Class<?> argType, Object arg) { + try { + Method method; + method = obj.getClass().getMethod( + methodName, new Class[] {argType}); + return method.invoke(obj, new Object[] {arg}); + } catch (Exception t) { + throwBuildException(t); + return null; // NotReached + } + } + + /** + * Call a method on the object with two argument. + * @param obj the object to invoke the method on. + * @param methodName the name of the method to call + * @param argType1 the type of the first argument. + * @param arg1 the value of the first argument. + * @param argType2 the type of the second argument. + * @param arg2 the value of the second argument. + * @return the object returned by the method + */ + public static Object invoke( + Object obj, String methodName, Class<?> argType1, Object arg1, + Class<?> argType2, Object arg2) { + try { + Method method; + method = obj.getClass().getMethod( + methodName, new Class[] {argType1, argType2}); + return method.invoke(obj, new Object[] {arg1, arg2}); + } catch (Exception t) { + throwBuildException(t); + return null; // NotReached + } + } + + /** + * Get the value of a field in an object. + * @param obj the object to look at. + * @param fieldName the name of the field in the object. + * @return the value of the field. + * @throws BuildException if there is an error. + */ + public static Object getField(Object obj, String fieldName) + throws BuildException { + try { + Field field = obj.getClass().getDeclaredField(fieldName); + field.setAccessible(true); + return field.get(obj); + } catch (Exception t) { + throwBuildException(t); + return null; // NotReached + } + } + + /** + * A method to convert an invocationTargetException to + * a buildexception and throw it. + * @param t the invocation target exception. + * @throws BuildException the converted exception. + */ + public static void throwBuildException(Exception t) + throws BuildException { + throw toBuildException(t); + } + + /** + * A method to convert an invocationTargetException to + * a buildexception. + * @param t the invocation target exception. + * @return the converted exception. + * @since ant 1.7.1 + */ + public static BuildException toBuildException(Exception t) { + if (t instanceof InvocationTargetException) { + Throwable t2 = ((InvocationTargetException) t) + .getTargetException(); + if (t2 instanceof BuildException) { + return (BuildException) t2; + } + return new BuildException(t2); + } else { + return new BuildException(t); + } + } + + /** + * A method to test if an object responds to a given + * message (method call) + * @param o the object + * @param methodName the method to check for + * @return true if the object has the method. + * @throws BuildException if there is a problem. + */ + public static boolean respondsTo(Object o, String methodName) + throws BuildException { + try { + Method[] methods = o.getClass().getMethods(); + for (int i = 0; i < methods.length; i++) { + if (methods[i].getName().equals(methodName)) { + return true; + } + } + return false; + } catch (Exception t) { + throw toBuildException(t); + } + } +} |