| /* |
| * Copyright 2002,2004 The Apache Software Foundation. |
| * |
| * Licensed 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.commons.jelly.tags.core; |
| |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.commons.jelly.JellyTagException; |
| import org.apache.commons.jelly.MissingAttributeException; |
| import org.apache.commons.jelly.TagSupport; |
| import org.apache.commons.jelly.XMLOutput; |
| import org.apache.commons.jelly.util.ClassLoaderUtils; |
| |
| /** |
| * A Tag which can invoke a static method on a class, without an |
| * instance of the class being needed. |
| * <p> |
| * Like the {@link InvokeTag}, this tag can take a set of |
| * arguments using the {@link ArgTag}. |
| * </p> |
| * <p> |
| * The following attributes are required:<br /> |
| * <ul> |
| * <li>var - The variable to assign the return of the method call to</li> |
| * <li>method - The name of the static method to invoke</li> |
| * <li>className - The name of the class containing the static method</li> |
| * </ul> |
| * </p> |
| * |
| * @author <a href="mailto:robert@bull-enterprises.com>Robert McIntosh</a> |
| * @version $Revision: 1.9 $ |
| */ |
| public class InvokeStaticTag extends TagSupport implements ArgTagParent { |
| |
| /** the variable exported */ |
| private String var; |
| |
| /** the variable where the method's exception is exported */ |
| private String exceptionVar; |
| |
| /** the method to invoke */ |
| private String methodName; |
| |
| /** the object to invoke the method on */ |
| private String className; |
| |
| private List paramTypes = new ArrayList(); |
| private List paramValues = new ArrayList(); |
| |
| public InvokeStaticTag() { |
| } |
| |
| /** |
| * Sets the name of the variable exported by this tag |
| * |
| * @param var The variable name |
| */ |
| public void setVar(String var) { |
| this.var = var; |
| } |
| |
| /** Sets the name of a variable that exports the exception thrown by |
| * the method's invocation (if any) |
| */ |
| public void setExceptionVar(String var) { |
| this.exceptionVar = var; |
| } |
| |
| /** |
| * Sets the name of the method to invoke |
| * |
| * @param method The method name |
| */ |
| public void setMethod(String methodName) { |
| this.methodName = methodName; |
| } |
| |
| /** |
| * Sets the fully qualified class name containing the static method |
| * |
| * @param className The name of the class |
| */ |
| public void setClassName(String className) { |
| this.className = className; |
| } |
| |
| /** |
| * Adds an argument to supply to the method |
| * |
| * @param type The Class type of the argument |
| * @param value The value of the argument |
| */ |
| public void addArgument(Class type, Object value) { |
| paramTypes.add(type); |
| paramValues.add(value); |
| } |
| |
| // Tag interface |
| //------------------------------------------------------------------------- |
| public void doTag(XMLOutput output) throws JellyTagException { |
| try { |
| if ( null == methodName) { |
| throw new MissingAttributeException( "method" ); |
| } |
| invokeBody(output); |
| |
| Object[] values = paramValues.toArray(); |
| Class[] types = (Class[])(paramTypes.toArray(new Class[paramTypes.size()])); |
| Method method = loadClass().getMethod( methodName, types ); |
| Object result = method.invoke( null, values ); |
| if(null != var) { |
| context.setVariable(var, result); |
| } |
| |
| ArgTag parentArg = (ArgTag)(findAncestorWithClass(ArgTag.class)); |
| if(null != parentArg) { |
| parentArg.setValue(result); |
| } |
| } |
| catch (ClassNotFoundException e) { |
| throw createLoadClassFailedException(e); |
| } |
| catch (NoSuchMethodException e) { |
| throw createLoadClassFailedException(e); |
| } |
| catch (IllegalAccessException e) { |
| throw createLoadClassFailedException(e); |
| } |
| catch (InvocationTargetException e) { |
| if(null != exceptionVar) { |
| context.setVariable(exceptionVar,e.getTargetException()); |
| } else { |
| throw new JellyTagException("method " + methodName + |
| " threw exception: "+ e.getTargetException().getMessage(), |
| e.getTargetException() ); |
| } |
| } |
| finally { |
| paramTypes.clear(); |
| paramValues.clear(); |
| } |
| } |
| |
| // Tag interface |
| //------------------------------------------------------------------------- |
| |
| /** |
| * Loads the class using either the class loader which loaded me or the |
| * current threads context class loader |
| */ |
| protected Class loadClass() throws ClassNotFoundException { |
| return ClassLoaderUtils.loadClass(className, getClass()); |
| } |
| |
| /** |
| * Factory method to create a new JellyTagException instance from a given |
| * failure exception |
| * @param e is the exception which occurred attempting to load the class |
| * @return JellyTagException |
| */ |
| protected JellyTagException createLoadClassFailedException(Exception e) { |
| return new JellyTagException( |
| "Could not load class: " + className + ". Reason: " + e, e |
| ); |
| } |
| } |
| |