javax.el.BeanELResolver 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.beans.BeanInfo;
import java.beans.FeatureDescriptor;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Objects;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentHashMap;
public class BeanELResolver extends ELResolver {
private static final int CACHE_SIZE;
private static final String CACHE_SIZE_PROP =
"org.apache.el.BeanELResolver.CACHE_SIZE";
static {
String cacheSizeStr;
if (System.getSecurityManager() == null) {
cacheSizeStr = System.getProperty(CACHE_SIZE_PROP, "1000");
} else {
cacheSizeStr = AccessController.doPrivileged(
new PrivilegedAction() {
@Override
public String run() {
return System.getProperty(CACHE_SIZE_PROP, "1000");
}
});
}
CACHE_SIZE = Integer.parseInt(cacheSizeStr);
}
private final boolean readOnly;
private final ConcurrentCache cache =
new ConcurrentCache<>(CACHE_SIZE);
public BeanELResolver() {
this.readOnly = false;
}
public BeanELResolver(boolean readOnly) {
this.readOnly = readOnly;
}
@Override
public Class getType(ELContext context, Object base, Object property) {
Objects.requireNonNull(context);
if (base == null || property == null) {
return null;
}
context.setPropertyResolved(base, property);
return this.property(context, base, property).getPropertyType();
}
@Override
public Object getValue(ELContext context, Object base, Object property) {
Objects.requireNonNull(context);
if (base == null || property == null) {
return null;
}
context.setPropertyResolved(base, property);
Method m = this.property(context, base, property).read(context, base);
try {
return m.invoke(base, (Object[]) null);
} catch (InvocationTargetException e) {
Throwable cause = e.getCause();
Util.handleThrowable(cause);
throw new ELException(Util.message(context, "propertyReadError",
base.getClass().getName(), property.toString()), cause);
} catch (Exception e) {
throw new ELException(e);
}
}
@Override
public void setValue(ELContext context, Object base, Object property,
Object value) {
Objects.requireNonNull(context);
if (base == null || property == null) {
return;
}
context.setPropertyResolved(base, property);
if (this.readOnly) {
throw new PropertyNotWritableException(Util.message(context,
"resolverNotWriteable", base.getClass().getName()));
}
Method m = this.property(context, base, property).write(context, base);
try {
m.invoke(base, value);
} catch (InvocationTargetException e) {
Throwable cause = e.getCause();
Util.handleThrowable(cause);
throw new ELException(Util.message(context, "propertyWriteError",
base.getClass().getName(), property.toString()), cause);
} catch (Exception e) {
throw new ELException(e);
}
}
/**
* @since EL 2.2
*/
@Override
public Object invoke(ELContext context, Object base, Object method,
Class[] paramTypes, Object[] params) {
Objects.requireNonNull(context);
if (base == null || method == null) {
return null;
}
ExpressionFactory factory = ELManager.getExpressionFactory();
String methodName = (String) factory.coerceToType(method, String.class);
// Find the matching method
Method matchingMethod =
Util.findMethod(base.getClass(), base, methodName, paramTypes, params);
Object[] parameters = Util.buildParameters(
matchingMethod.getParameterTypes(), matchingMethod.isVarArgs(),
params);
Object result = null;
try {
result = matchingMethod.invoke(base, parameters);
} catch (IllegalArgumentException | IllegalAccessException e) {
throw new ELException(e);
} catch (InvocationTargetException e) {
Throwable cause = e.getCause();
Util.handleThrowable(cause);
throw new ELException(cause);
}
context.setPropertyResolved(base, method);
return result;
}
@Override
public boolean isReadOnly(ELContext context, Object base, Object property) {
Objects.requireNonNull(context);
if (base == null || property == null) {
return false;
}
context.setPropertyResolved(base, property);
return this.readOnly || this.property(context, base, property).isReadOnly(base);
}
@Override
public Iterator getFeatureDescriptors(ELContext context, Object base) {
if (base == null) {
return null;
}
try {
BeanInfo info = Introspector.getBeanInfo(base.getClass());
PropertyDescriptor[] pds = info.getPropertyDescriptors();
for (int i = 0; i < pds.length; i++) {
pds[i].setValue(RESOLVABLE_AT_DESIGN_TIME, Boolean.TRUE);
pds[i].setValue(TYPE, pds[i].getPropertyType());
}
return Arrays.asList((FeatureDescriptor[]) pds).iterator();
} catch (IntrospectionException e) {
//
}
return null;
}
@Override
public Class getCommonPropertyType(ELContext context, Object base) {
if (base != null) {
return Object.class;
}
return null;
}
static final 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));
}
if (System.getSecurityManager() != null) {
// When running with SecurityManager, some classes may be
// not accessible, but have accessible interfaces.
populateFromInterfaces(type);
}
} catch (IntrospectionException ie) {
throw new ELException(ie);
}
}
private void populateFromInterfaces(Class aClass) throws IntrospectionException {
Class interfaces[] = aClass.getInterfaces();
if (interfaces.length > 0) {
for (Class ifs : interfaces) {
BeanInfo info = Introspector.getBeanInfo(ifs);
PropertyDescriptor[] pds = info.getPropertyDescriptors();
for (PropertyDescriptor pd : pds) {
if (!this.properties.containsKey(pd.getName())) {
this.properties.put(pd.getName(), new BeanProperty(
this.type, pd));
}
}
populateFromInterfaces(ifs);
}
}
Class superclass = aClass.getSuperclass();
if (superclass != null) {
populateFromInterfaces(superclass);
}
}
private BeanProperty get(ELContext ctx, String name) {
BeanProperty property = this.properties.get(name);
if (property == null) {
throw new PropertyNotFoundException(Util.message(ctx,
"propertyNotFound", type.getName(), name));
}
return property;
}
private Class getType() {
return type;
}
}
static final 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(Object base) {
return this.write == null &&
(null == (this.write = Util.getMethod(this.owner, base, descriptor.getWriteMethod())));
}
private Method write(ELContext ctx, Object base) {
if (this.write == null) {
this.write = Util.getMethod(this.owner, base, descriptor.getWriteMethod());
if (this.write == null) {
throw new PropertyNotWritableException(Util.message(ctx,
"propertyNotWritable", new Object[] {
owner.getName(), descriptor.getName() }));
}
}
return this.write;
}
private Method read(ELContext ctx, Object base) {
if (this.read == null) {
this.read = Util.getMethod(this.owner, base, descriptor.getReadMethod());
if (this.read == null) {
throw new PropertyNotFoundException(Util.message(ctx,
"propertyNotReadable", new Object[] {
owner.getName(), descriptor.getName() }));
}
}
return this.read;
}
}
private final 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 final 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) {
synchronized (longterm) {
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) {
synchronized (longterm) {
this.longterm.putAll(this.eden);
}
this.eden.clear();
}
this.eden.put(key, value);
}
}
}
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