org.apache.struts2.views.gxp.Gxp Maven / Gradle / Ivy
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* 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.struts2.views.gxp;
import com.google.common.base.Function;
import com.google.common.collect.MapMaker;
import com.google.gxp.html.HtmlClosure;
import java.lang.reflect.Method;
import java.util.Map;
/**
* Struts 2 to GXP adapter. Can be used to write a GXP or create
* a HtmlClosure. Pulls GXP parameters from Struts 2 value stack.
*
* @author Bob Lee
*/
public class Gxp extends AbstractGxp {
Gxp(Class gxpClass) {
this(gxpClass, lookupMethodByName(gxpClass, "write"), lookupMethodByName(gxpClass, "getGxpClosure"));
}
Gxp(Class gxpClass, Method writeMethod, Method getGxpClosureMethod) {
super(gxpClass, writeMethod, getGxpClosureMethod);
}
static final Map classToGxp = new MapMaker().weakKeys().softValues().makeComputingMap(new Function() {
public Gxp apply(Class from) {
return classToGxp.containsKey(from) ? classToGxp.get(from) : new Gxp(from);
}
});
static final Map pathToGxp = new MapMaker().softValues().makeComputingMap(new Function() {
public Gxp apply(String from) {
return pathToGxp.containsKey(from) ? pathToGxp.get(from) : getInstance(getGxpClassForPath(from));
}
});
/**
* Looks up Gxp instance for GXP with given path.
*
* @param gxpPath Gxp path
*
* @return Gxp instance
*/
public static Gxp getInstance(String gxpPath) {
try {
return pathToGxp.get(gxpPath);
} catch (RuntimeException e) {
if (e.getCause() instanceof ClassNotFoundException) {
// Couldn't find or load the GXP class. Return null.
// It would be simpler if classToGxp.create() could return null,
// but the contract of ReferenceCache doesn't allow it to.
return null;
}
throw e;
}
}
/**
* Looks up Gxp instance for the given GXP class.
*
* @param gxpClass Gxp class
*
* @return Gxp instance
*/
public static Gxp getInstance(Class gxpClass) {
return classToGxp.get(gxpClass);
}
}