/*
* 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 jakarta.el;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentHashMap;
/**
* Standard ELResolver for working with JavaBeans.
*/
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 {
CACHE_SIZE = Integer.getInteger(CACHE_SIZE_PROP, 1000).intValue();
}
private final boolean readOnly;
private final ConcurrentCache<String,BeanProperties> cache = new ConcurrentCache<>(CACHE_SIZE);
/**
* Creates a writable instance of the standard JavaBean resolver.
*/
public BeanELResolver() {
this.readOnly = false;
}
/**
* Creates an instance of the standard JavaBean resolver.
*
* @param readOnly {@code true} if the created instance should be read-only otherwise 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);
BeanProperty beanProperty = property(context, base, property);
if (readOnly || beanProperty.isReadOnly(base)) {
return null;
}
return beanProperty.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, "resolverNotWritable", 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);
}
}
@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 = factory.coerceToType(method, String.class);
// Find the matching method
Method matchingMethod = Util.findMethod(context, base.getClass(), base, methodName, paramTypes, params);
Object[] parameters =
Util.buildParameters(context, matchingMethod.getParameterTypes(), matchingMethod.isVarArgs(), params);
Object result;
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 Class<?> getCommonPropertyType(ELContext context, Object base) {
if (base != null) {
return Object.class;
}
return null;
}
abstract static class BeanProperties {
protected final Map<String,BeanProperty> properties;
protected final Class<?> type;
BeanProperties(Class<?> type) throws ELException {
this.type = type;
this.properties = new HashMap<>();
}
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;
}
}
abstract static class BeanProperty {
private final Class<?> type;
private final Class<?> owner;
private Method read;
private Method write;
BeanProperty(Class<?> owner, Class<?> type) {
this.owner = owner;
this.type = type;
}
public Class<?> getPropertyType() {
return this.type;
}
public boolean isReadOnly(Object base) {
return this.write == null && (null == (this.write = Util.getMethod(this.owner, base, getWriteMethod())));
}
private Method write(ELContext ctx, Object base) {
if (this.write == null) {
this.write = Util.getMethod(this.owner, base, getWriteMethod());
if (this.write == null) {
throw new PropertyNotWritableException(
Util.message(ctx, "propertyNotWritable", owner.getName(), getName()));
}
}
return this.write;
}
private Method read(ELContext ctx, Object base) {
if (this.read == null) {
this.read = Util.getMethod(this.owner, base, getReadMethod());
if (this.read == null) {
throw new PropertyNotFoundException(
Util.message(ctx, "propertyNotReadable", owner.getName(), getName()));
}
}
return this.read;
}
abstract Method getWriteMethod();
abstract Method getReadMethod();
abstract String getName();
}
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 = BeanSupport.getInstance().getBeanProperties(type);
this.cache.put(type.getName(), props);
}
return props.get(ctx, prop);
}
private static final class ConcurrentCache<K, V> {
private final int size;
private final Map<K,V> eden;
private final Map<K,V> longterm;
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);
}
}
}