org.apache.jasper.el.ELContextImpl 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 org.apache.jasper.el;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
import javax.el.ArrayELResolver;
import javax.el.BeanELResolver;
import javax.el.BeanNameELResolver;
import javax.el.BeanNameResolver;
import javax.el.CompositeELResolver;
import javax.el.ELContext;
import javax.el.ELManager;
import javax.el.ELResolver;
import javax.el.ExpressionFactory;
import javax.el.FunctionMapper;
import javax.el.ListELResolver;
import javax.el.MapELResolver;
import javax.el.ResourceBundleELResolver;
import javax.el.StandardELContext;
import javax.el.StaticFieldELResolver;
import javax.el.ValueExpression;
import javax.el.VariableMapper;
import javax.servlet.jsp.el.ImplicitObjectELResolver;
import javax.servlet.jsp.el.ScopedAttributeELResolver;
import io.undertow.jsp.ImportedClassELResolver;
import org.apache.jasper.Constants;
/**
* Implementation of ELContext
*
* @author Jacob Hookom
*/
public final class ELContextImpl extends ELContext {
private static final FunctionMapper NullFunctionMapper = new FunctionMapper() {
@Override
public Method resolveFunction(String prefix, String localName) {
return null;
}
};
private static final class VariableMapperImpl 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 final CompositeELResolver DefaultResolver;
static {
if (Constants.IS_SECURITY_ENABLED) {
DefaultResolver = null;
} else {
DefaultResolver = new CompositeELResolver();
((CompositeELResolver) DefaultResolver).add(ELManager.getExpressionFactory().getStreamELResolver());
((CompositeELResolver) DefaultResolver).add(new StaticFieldELResolver());
((CompositeELResolver) DefaultResolver).add(new MapELResolver());
((CompositeELResolver) DefaultResolver).add(new ResourceBundleELResolver());
((CompositeELResolver) DefaultResolver).add(new ListELResolver());
((CompositeELResolver) DefaultResolver).add(new ArrayELResolver());
((CompositeELResolver) DefaultResolver).add(new BeanELResolver());
}
}*/
//private final ELResolver resolver;
//private FunctionMapper functionMapper = new DefaultFunctionMapper();
/*private VariableMapper variableMapper;
*/
/*public ELContextImpl(ExpressionFactory factory) {
super(factory);
}
public ELContextImpl(ELResolver resolver){
super(ELManager.getExpressionFactory());
//addELResolver(resolver);
addELResolver(new ImplicitObjectELResolver());
addELResolver(new ScopedAttributeELResolver());
//this.resolver = resolver;
}*/
/*
* The ELResolver for this ELContext.
*/
private ELResolver elResolver;
/*
* The list of the custom ELResolvers added to the ELResolvers.
* An ELResolver is added to the list when addELResolver is called.
*/
private CompositeELResolver customResolvers;
/*
* The ELResolver implementing the query operators.
*/
private ELResolver streamELResolver;
/*
* The FunctionMapper for this ELContext.
*/
private FunctionMapper functionMapper;
/*
* The pre-confured init function map;
*/
private Map initFunctionMap;
/*
* The VariableMapper for this ELContext.
*/
private VariableMapper variableMapper;
/*
* If non-null, indicates the presence of a delegate ELContext.
* When a Standard is constructed from another ELContext, there is no
* easy way to get its private context map, therefore delegation is needed.
*/
private ELContext delegate = null;
/**
* A bean repository local to this context
*/
private Map beans = new HashMap();
/**
* Construct a default ELContext for a stand-alone environment.
*
* @param factory The ExpressionFactory
*/
public ELContextImpl(ExpressionFactory factory) {
this.streamELResolver = factory.getStreamELResolver();
initFunctionMap = factory.getInitFunctionMap();
}
/**
* Construct a StandardELContext from another ELContext.
*
* @param context The ELContext that acts as a delegate in most cases
*/
public ELContextImpl(ELContext context) {
this.delegate = context;
// Copy all attributes except map and resolved
CompositeELResolver elr = new CompositeELResolver();
elr.add(new BeanNameELResolver(new LocalBeanNameResolver()));
customResolvers = new CompositeELResolver();
elr.add(customResolvers);
elr.add(context.getELResolver());
elResolver = elr;
functionMapper = context.getFunctionMapper();
variableMapper = context.getVariableMapper();
setLocale(context.getLocale());
}
@Deprecated
public ELContextImpl(ELResolver context,ExpressionFactory factory) {
this(factory);
getELResolver();
addELResolver(context);
}
@Override
public void putContext(Class key, Object contextObject) {
if (delegate != null) {
delegate.putContext(key, contextObject);
} else {
super.putContext(key, contextObject);
}
}
@Override
public Object getContext(Class key) {
if (delegate != null) {
return delegate.getContext(key);
} else {
return super.getContext(key);
}
}
/**
* Construct (if needed) and return a default ELResolver.
* Retrieves the ELResolver associated with this context.
* This is a CompositeELResover consists of an ordered list of
* ELResolvers.
*
* - A {@link BeanNameELResolver} for beans defined locally
* - Any custom
ELResolvers
* - An
ELResolver supporting the collection operations
* - A {@link StaticFieldELResolver} for resolving static fields
* - A {@link MapELResolver} for resolving Map properties
* - A {@link ResourceBundleELResolver} for resolving ResourceBundle properties
* - A {@link ListELResolver} for resolving List properties
* - An {@link ArrayELResolver} for resolving array properties
* - A {@link BeanELResolver} for resolving bean properties
*
*
*
* @return The ELResolver for this context.
*/
@Override
public ELResolver getELResolver() {
if (elResolver == null) {
CompositeELResolver resolver = new CompositeELResolver();
customResolvers = new CompositeELResolver();
resolver.add(new ImplicitObjectELResolver());
resolver.add(customResolvers);
resolver.add(new BeanNameELResolver(new LocalBeanNameResolver()));
if (streamELResolver != null) {
resolver.add(streamELResolver);
}
resolver.add(new StaticFieldELResolver());
resolver.add(new ImportedClassELResolver());//to make static fields & methods work
resolver.add(new MapELResolver());
resolver.add(new ResourceBundleELResolver());
resolver.add(new ListELResolver());
resolver.add(new ArrayELResolver());
resolver.add(new BeanELResolver());
resolver.add(new ScopedAttributeELResolver());
elResolver = resolver;
}
return elResolver;
}
/**
* Add a custom ELResolver to the context. The list of the custom
* ELResolvers will be accessed in the order they are added.
* A custom ELResolver added to the context cannot be removed.
*
* @param cELResolver The new ELResolver to be added to the context
*/
public void addELResolver(ELResolver cELResolver) {
getELResolver(); // make sure elResolver is constructed
customResolvers.add(cELResolver);
}
/**
* Get the local bean repository
*
* @return the bean repository
*/
Map getBeans() {
return beans;
}
/**
* Construct (if needed) and return a default FunctionMapper.
*
* @return The default FunctionMapper
*/
@Override
public FunctionMapper getFunctionMapper() {
if (functionMapper == null) {
functionMapper = new DefaultFunctionMapper(initFunctionMap);
}
return functionMapper;
}
public void setFunctionMapper(FunctionMapper functionMapper) {
this.functionMapper = functionMapper;
}
/**
* Construct (if needed) and return a default VariableMapper() {
*
* @return The default Variable
*/
@Override
public VariableMapper getVariableMapper() {
if (variableMapper == null) {
variableMapper = new DefaultVariableMapper();
}
return variableMapper;
}
private static class DefaultFunctionMapper extends FunctionMapper {
private Map functions = null;
DefaultFunctionMapper(Map initMap) {
functions = (initMap == null) ?
new HashMap() :
new HashMap(initMap);
}
@Override
public Method resolveFunction(String prefix, String localName) {
return functions.get(prefix + ":" + localName);
}
@Override
public void mapFunction(String prefix, String localName, Method meth) {
functions.put(prefix + ":" + localName, meth);
}
}
private static class DefaultVariableMapper extends VariableMapper {
private Map variables = null;
@Override
public ValueExpression resolveVariable(String variable) {
if (variables == null) {
return null;
}
return variables.get(variable);
}
@Override
public ValueExpression setVariable(String variable,
ValueExpression expression) {
if (variables == null) {
variables = new HashMap();
}
ValueExpression prev = null;
if (expression == null) {
prev = variables.remove(variable);
} else {
prev = variables.put(variable, expression);
}
return prev;
}
}
private class LocalBeanNameResolver extends BeanNameResolver {
@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) {
beans.put(beanName, value);
}
@Override
public boolean isReadOnly(String beanName) {
return false;
}
@Override
public boolean canCreateBean(String beanName) {
return true;
}
}
}