javax.el.StandardELContext Maven / Gradle / Ivy
/*
* 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 javax.el;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
/**
* @since EL 3.0
*/
public class StandardELContext extends ELContext {
private final ELContext wrappedContext;
private final VariableMapper variableMapper;
private final FunctionMapper functionMapper;
private final CompositeELResolver standardResolver;
private final CompositeELResolver customResolvers;
private final Map localBeans = new HashMap<>();
public StandardELContext(ExpressionFactory factory) {
wrappedContext = null;
variableMapper = new StandardVariableMapper();
functionMapper = new StandardFunctionMapper(factory.getInitFunctionMap());
standardResolver = new CompositeELResolver();
customResolvers = new CompositeELResolver();
ELResolver streamResolver = factory.getStreamELResolver();
// Add resolvers in order
standardResolver.add(new BeanNameELResolver(new StandardBeanNameResolver(localBeans)));
standardResolver.add(customResolvers);
if (streamResolver != null) {
standardResolver.add(streamResolver);
}
standardResolver.add(new StaticFieldELResolver());
standardResolver.add(new MapELResolver());
standardResolver.add(new ResourceBundleELResolver());
standardResolver.add(new ListELResolver());
standardResolver.add(new ArrayELResolver());
standardResolver.add(new BeanELResolver());
}
public StandardELContext(ELContext context) {
wrappedContext = context;
variableMapper = context.getVariableMapper();
functionMapper = context.getFunctionMapper();
standardResolver = new CompositeELResolver();
customResolvers = new CompositeELResolver();
// Add resolvers in order
standardResolver.add(new BeanNameELResolver(new StandardBeanNameResolver(localBeans)));
standardResolver.add(customResolvers);
// Use resolvers from context from this point on
standardResolver.add(context.getELResolver());
}
// Can't use Class because API needs to match specification
@Override
public void putContext(@SuppressWarnings("rawtypes") Class key, Object contextObject) {
if (wrappedContext == null) {
super.putContext(key, contextObject);
} else {
wrappedContext.putContext(key, contextObject);
}
}
@Override
public Object getContext(@SuppressWarnings("rawtypes") Class key) {
if (wrappedContext == null) {
return super.getContext(key);
} else {
return wrappedContext.getContext(key);
}
}
@Override
public ELResolver getELResolver() {
return standardResolver;
}
public void addELResolver(ELResolver resolver) {
customResolvers.add(resolver);
}
@Override
public FunctionMapper getFunctionMapper() {
return functionMapper;
}
@Override
public VariableMapper getVariableMapper() {
return variableMapper;
}
Map getLocalBeans() {
return localBeans;
}
private static class StandardVariableMapper extends VariableMapper {
private Map vars;
@Override
public ValueExpression resolveVariable(String variable) {
if (vars == null) {
return null;
}
return vars.get(variable);
}
@Override
public ValueExpression setVariable(String variable, ValueExpression expression) {
if (vars == null) {
vars = new HashMap<>();
}
if (expression == null) {
return vars.remove(variable);
} else {
return vars.put(variable, expression);
}
}
}
private static class StandardBeanNameResolver extends BeanNameResolver {
private final Map beans;
StandardBeanNameResolver(Map beans) {
this.beans = beans;
}
@Override
public boolean isNameResolved(String beanName) {
return beans.containsKey(beanName);
}
@Override
public Object getBean(String beanName) {
return beans.get(beanName);
}
@Override
public void setBeanValue(String beanName, Object value) throws PropertyNotWritableException {
beans.put(beanName, value);
}
@Override
public boolean isReadOnly(String beanName) {
return false;
}
@Override
public boolean canCreateBean(String beanName) {
return true;
}
}
private static class StandardFunctionMapper extends FunctionMapper {
private final Map methods = new HashMap<>();
StandardFunctionMapper(Map initFunctionMap) {
if (initFunctionMap != null) {
methods.putAll(initFunctionMap);
}
}
@Override
public Method resolveFunction(String prefix, String localName) {
String key = prefix + ':' + localName;
return methods.get(key);
}
@Override
public void mapFunction(String prefix, String localName, Method method) {
String key = prefix + ':' + localName;
if (method == null) {
methods.remove(key);
} else {
methods.put(key, method);
}
}
}
}