javax.el.BeanELResolver 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 javax.el;
import java.beans.BeanInfo;
import java.beans.FeatureDescriptor;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentHashMap;
public class BeanELResolver extends ELResolver {
private final boolean readOnly;
private final ConcurrentCache cache = new ConcurrentCache(
1000);
public BeanELResolver() {
this.readOnly = false;
}
public BeanELResolver(boolean readOnly) {
this.readOnly = readOnly;
}
public Object getValue(ELContext context, Object base, Object property)
throws NullPointerException, PropertyNotFoundException, ELException {
if (context == null) {
throw new NullPointerException();
}
if (base == null || property == null) {
return null;
}
context.setPropertyResolved(true);
Method m = this.property(context, base, property).read(context);
try {
return m.invoke(base, (Object[]) null);
} catch (IllegalAccessException e) {
throw new ELException(e);
} catch (InvocationTargetException e) {
throw new ELException(message(context, "propertyReadError",
new Object[] { base.getClass().getName(),
property.toString() }), e.getCause());
} catch (Exception e) {
throw new ELException(e);
}
}
public Class getType(ELContext context, Object base, Object property)
throws NullPointerException, PropertyNotFoundException, ELException {
if (context == null) {
throw new NullPointerException();
}
if (base == null || property == null) {
return null;
}
context.setPropertyResolved(true);
return this.property(context, base, property).getPropertyType();
}
public void setValue(ELContext context, Object base, Object property,
Object value) throws NullPointerException,
PropertyNotFoundException, PropertyNotWritableException,
ELException {
if (context == null) {
throw new NullPointerException();
}
if (base == null || property == null) {
return;
}
context.setPropertyResolved(true);
if (this.readOnly) {
throw new PropertyNotWritableException(message(context,
"resolverNotWriteable", new Object[] { base.getClass()
.getName() }));
}
Method m = this.property(context, base, property).write(context);
try {
m.invoke(base, value);
} catch (IllegalAccessException e) {
throw new ELException(e);
} catch (InvocationTargetException e) {
throw new ELException(message(context, "propertyWriteError",
new Object[] { base.getClass().getName(),
property.toString() }), e.getCause());
} catch (Exception e) {
throw new ELException(e);
}
}
public boolean isReadOnly(ELContext context, Object base, Object property)
throws NullPointerException, PropertyNotFoundException, ELException {
if (context == null) {
throw new NullPointerException();
}
if (base == null || property == null) {
return false;
}
context.setPropertyResolved(true);
return this.readOnly
|| this.property(context, base, property).isReadOnly();
}
public Iterator getFeatureDescriptors(ELContext context, Object base) {
if (context == null) {
throw new NullPointerException();
}
if (base == null) {
return null;
}
try {
BeanInfo info = Introspector.getBeanInfo(base.getClass());
PropertyDescriptor[] pds = info.getPropertyDescriptors();
for (PropertyDescriptor pd : pds) {
pd.setValue(RESOLVABLE_AT_DESIGN_TIME, Boolean.TRUE);
pd.setValue(TYPE, pd.getPropertyType());
}
return Arrays.asList((FeatureDescriptor[]) pds).iterator();
} catch (IntrospectionException e) {
//
}
return null;
}
public Class getCommonPropertyType(ELContext context, Object base) {
if (context == null) {
throw new NullPointerException();
}
if (base != null) {
return Object.class;
}
return null;
}
protected final static class BeanProperties {
private final Map properties;
private final Class type;
public BeanProperties(Class type) throws ELException {
this.type = type;
this.properties = new HashMap();
try {
BeanInfo info = Introspector.getBeanInfo(this.type);
PropertyDescriptor[] pds = info.getPropertyDescriptors();
for (PropertyDescriptor pd : pds) {
this.properties.put(pd.getName(), new BeanProperty(
type, pd));
}
} catch (IntrospectionException ie) {
throw new ELException(ie);
}
}
private BeanProperty get(ELContext ctx, String name) {
BeanProperty property = this.properties.get(name);
if (property == null) {
throw new PropertyNotFoundException(message(ctx,
"propertyNotFound",
new Object[] { type.getName(), name }));
}
return property;
}
public BeanProperty getBeanProperty(String name) {
return get(null, name);
}
private Class getType() {
return type;
}
}
protected final static class BeanProperty {
private final Class type;
private final Class owner;
private final PropertyDescriptor descriptor;
private Method read;
private Method write;
public BeanProperty(Class owner, PropertyDescriptor descriptor) {
this.owner = owner;
this.descriptor = descriptor;
this.type = descriptor.getPropertyType();
}
public Class getPropertyType() {
return this.type;
}
public boolean isReadOnly() {
return this.write == null
&& (null == (this.write = getMethod(this.owner, descriptor.getWriteMethod())));
}
public Method getWriteMethod() {
return write(null);
}
public Method getReadMethod() {
return this.read(null);
}
private Method write(ELContext ctx) {
if (this.write == null) {
this.write = getMethod(this.owner, descriptor.getWriteMethod());
if (this.write == null) {
throw new PropertyNotFoundException(message(ctx,
"propertyNotWritable", new Object[] {
type.getName(), descriptor.getName() }));
}
}
return this.write;
}
private Method read(ELContext ctx) {
if (this.read == null) {
this.read = getMethod(this.owner, descriptor.getReadMethod());
if (this.read == null) {
throw new PropertyNotFoundException(message(ctx,
"propertyNotReadable", new Object[] {
type.getName(), descriptor.getName() }));
}
}
return this.read;
}
}
private BeanProperty property(ELContext ctx, Object base,
Object property) {
Class type = base.getClass();
String prop = property.toString();
BeanProperties props = this.cache.get(type.getName());
if (props == null || type != props.getType()) {
props = new BeanProperties(type);
this.cache.put(type.getName(), props);
}
return props.get(ctx, prop);
}
private static Method getMethod(Class type, Method m) {
if (m == null || Modifier.isPublic(type.getModifiers())) {
return m;
}
Class[] inf = type.getInterfaces();
Method mp;
for (Class anInf : inf) {
try {
mp = anInf.getMethod(m.getName(), m.getParameterTypes());
mp = getMethod(mp.getDeclaringClass(), mp);
if (mp != null) {
return mp;
}
} catch (NoSuchMethodException e) {
//continue
}
}
Class sup = type.getSuperclass();
if (sup != null) {
try {
mp = sup.getMethod(m.getName(), m.getParameterTypes());
mp = getMethod(mp.getDeclaringClass(), mp);
if (mp != null) {
return mp;
}
} catch (NoSuchMethodException e) {
//continue
}
}
return null;
}
private final static class ConcurrentCache {
private final int size;
private final Map eden;
private final Map longterm;
public ConcurrentCache(int size) {
this.size = size;
this.eden = new ConcurrentHashMap(size);
this.longterm = new WeakHashMap(size);
}
public V get(K key) {
V value = this.eden.get(key);
if (value == null) {
value = this.longterm.get(key);
if (value != null) {
this.eden.put(key, value);
}
}
return value;
}
public void put(K key, V value) {
if (this.eden.size() >= this.size) {
this.longterm.putAll(this.eden);
this.eden.clear();
}
this.eden.put(key, value);
}
}
public Object invoke(ELContext context, Object base, Object method, Class[] paramTypes, Object[] params) {
if (context == null) {
throw new NullPointerException("ELContext could not be nulll");
}
// Why static invocation is not supported
if(base == null || method == null) {
return null;
}
if (params == null) {
params = new Object[0];
}
ExpressionFactory expressionFactory = null;
if (ELUtils.isCachedExpressionFactoryEnabled()) {
expressionFactory = ELUtils.getCachedExpressionFactory();
}
if (expressionFactory == null) {
expressionFactory = ExpressionFactory.newInstance();
}
String methodName = (String) expressionFactory.coerceToType(method, String.class);
if (methodName.length() == 0) {
throw new MethodNotFoundException("The parameter method could not be zero-length");
}
Class targetClass = base.getClass();
if (methodName.equals("") || methodName.equals("")) {
throw new MethodNotFoundException(method + " is not found in target class " + targetClass.getName());
}
Method targetMethod = null;
if (paramTypes == null) {
int paramsNumber = params.length;
for (Method m : targetClass.getMethods()) {
if (m.getName().equals(methodName) && m.getParameterTypes().length == paramsNumber) {
targetMethod = m;
break;
}
}
if (targetMethod == null) {
for (Method m : targetClass.getMethods()) {
if (m.getName().equals(methodName) && m.isVarArgs() && paramsNumber >= (m.getParameterTypes().length - 1)) {
targetMethod = m;
break;
}
}
}
} else {
try {
targetMethod = targetClass.getMethod(methodName, paramTypes);
} catch (SecurityException e) {
throw new ELException(e);
} catch (NoSuchMethodException e) {
throw new MethodNotFoundException(e);
}
}
if (targetMethod == null) {
throw new MethodNotFoundException(method + " is not found in target class " + targetClass.getName());
}
if (paramTypes == null) {
paramTypes = targetMethod.getParameterTypes();
}
//Initial check whether the types and parameter values length
if (targetMethod.isVarArgs()) {
if (paramTypes.length - 1 > params.length) {
throw new IllegalArgumentException("Inconsistent number between argument types and values");
}
} else if (paramTypes.length != params.length) {
throw new IllegalArgumentException("Inconsistent number between argument types and values");
}
try {
Object[] finalParamValues = new Object[paramTypes.length];
//Only do the parameter conversion while the method is not a non-parameter one
if (paramTypes.length > 0) {
int iCurrentIndex = 0;
for (int iLoopSize = paramTypes.length - 1; iCurrentIndex < iLoopSize; iCurrentIndex++) {
finalParamValues[iCurrentIndex] = expressionFactory.coerceToType(params[iCurrentIndex], paramTypes[iCurrentIndex]);
}
/**
* Not sure it is over-designed. Do not find detailed description about how the parameter values are passed if the method is of variable arguments.
* It might be an array directly passed or each parameter value passed one by one.
*/
if (targetMethod.isVarArgs()) {
// varArgsClassType should be an array type
Class varArgsClassType = paramTypes[iCurrentIndex];
// 1. If there is no parameter value left for the variable argument, create a zero-length array
// 2. If there is only one parameter value left for the variable argument, and it has the same array type with the varArgsClass, pass in directly
// 3. Else, create an array of varArgsClass type, and add all the left coerced parameter values
if (iCurrentIndex == params.length) {
finalParamValues[iCurrentIndex] = Array.newInstance(varArgsClassType.getComponentType(), 0);
} else if (iCurrentIndex == params.length - 1 && varArgsClassType == params[iCurrentIndex].getClass()
&& varArgsClassType.getClassLoader() == params[iCurrentIndex].getClass().getClassLoader()) {
finalParamValues[iCurrentIndex] = params[iCurrentIndex];
} else {
Object targetArray = Array.newInstance(varArgsClassType.getComponentType(), params.length - iCurrentIndex);
Class componentClassType = varArgsClassType.getComponentType();
for (int i = 0, iLoopSize = params.length - iCurrentIndex; i < iLoopSize; i++) {
Array.set(targetArray, i, expressionFactory.coerceToType(iCurrentIndex + i, componentClassType));
}
finalParamValues[iCurrentIndex] = targetArray;
}
} else {
finalParamValues[iCurrentIndex] = expressionFactory.coerceToType(params[iCurrentIndex], paramTypes[iCurrentIndex]);
}
}
Object retValue = targetMethod.invoke(base, finalParamValues);
context.setPropertyResolved(true);
return retValue;
} catch (IllegalAccessException e) {
throw new ELException(e);
} catch (InvocationTargetException e) {
throw new ELException(e.getCause());
}
}
}