| package org.apache.velocity.runtime.parser.node; |
| |
| /* |
| * 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. |
| */ |
| |
| import org.apache.velocity.exception.VelocityException; |
| import org.apache.velocity.util.introspection.Introspector; |
| import org.slf4j.Logger; |
| |
| import java.lang.reflect.InvocationTargetException; |
| |
| |
| /** |
| * Executor that simply tries to execute a get(key) |
| * operation. This will try to find a get(key) method |
| * for any type of object, not just objects that |
| * implement the Map interface as was previously |
| * the case. |
| * |
| * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> |
| * @version $Id$ |
| */ |
| public class GetExecutor extends AbstractExecutor |
| { |
| private final Introspector introspector; |
| |
| // This is still threadsafe because this object is only read except in the C'tor. |
| private Object [] params = {}; |
| |
| /** |
| * @param log |
| * @param introspector |
| * @param clazz |
| * @param property |
| * @since 1.5 |
| */ |
| public GetExecutor(final Logger log, final Introspector introspector, |
| final Class clazz, final String property) |
| { |
| this.log = log; |
| this.introspector = introspector; |
| |
| // If you passed in null as property, we don't use the value |
| // for parameter lookup. Instead we just look for get() without |
| // any parameters. |
| // |
| // In any other case, the following condition will set up an array |
| // for looking up get(String) on the class. |
| |
| if (property != null) |
| { |
| this.params = new Object[] { property }; |
| } |
| discover(clazz); |
| } |
| |
| /** |
| * @param clazz |
| * @since 1.5 |
| */ |
| protected void discover(final Class clazz) |
| { |
| try |
| { |
| setMethod(introspector.getMethod(clazz, "get", params)); |
| /* get(Number) or get(integral) are NOT admissible, |
| * as the key is a string |
| */ |
| if (getMethod() != null) |
| { |
| Class<?> [] args = getMethod().getParameterTypes(); |
| if (args.length == 1 && (args[0].isPrimitive() || Number.class.isAssignableFrom(args[0]))) |
| { |
| setMethod(null); |
| } |
| } |
| } |
| /** |
| * pass through application level runtime exceptions |
| */ |
| catch( RuntimeException e ) |
| { |
| throw e; |
| } |
| catch(Exception e) |
| { |
| String msg = "Exception while looking for get('" + params[0] + "') method"; |
| log.error(msg, e); |
| throw new VelocityException(msg, e); |
| } |
| } |
| |
| /** |
| * @param o |
| * @return value |
| * @see org.apache.velocity.runtime.parser.node.AbstractExecutor#execute(java.lang.Object) |
| */ |
| public Object execute(final Object o) |
| throws IllegalAccessException, InvocationTargetException |
| { |
| return isAlive() ? getMethod().invoke(o, params) : null; |
| } |
| } |