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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.FeatureDescriptor;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Iterator;
import java.util.Objects;
/**
* @since EL 3.0
*/
public class StaticFieldELResolver extends ELResolver {
@Override
public Object getValue(ELContext context, Object base, Object property) {
Objects.requireNonNull(context);
if (base instanceof ELClass && property instanceof String) {
context.setPropertyResolved(base, property);
Class<?> clazz = ((ELClass) base).getKlass();
String name = (String) property;
Exception exception = null;
try {
Field field = clazz.getField(name);
int modifiers = field.getModifiers();
JreCompat jreCompat = JreCompat.getInstance();
if (Modifier.isStatic(modifiers) && Modifier.isPublic(modifiers) && jreCompat.canAccess(null, field)) {
return field.get(null);
}
} catch (IllegalArgumentException | IllegalAccessException | NoSuchFieldException | SecurityException e) {
exception = e;
}
String msg = Util.message(context, "staticFieldELResolver.notFound", name, clazz.getName());
if (exception == null) {
throw new PropertyNotFoundException(msg);
} else {
throw new PropertyNotFoundException(msg, exception);
}
}
return null;
}
@Override
public void setValue(ELContext context, Object base, Object property, Object value) {
Objects.requireNonNull(context);
if (base instanceof ELClass && property instanceof String) {
Class<?> clazz = ((ELClass) base).getKlass();
String name = (String) property;
throw new PropertyNotWritableException(
Util.message(context, "staticFieldELResolver.notWritable", name, clazz.getName()));
}
}
@Override
public Object invoke(ELContext context, Object base, Object method, Class<?>[] paramTypes, Object[] params) {
Objects.requireNonNull(context);
if (base instanceof ELClass && method instanceof String) {
context.setPropertyResolved(base, method);
Class<?> clazz = ((ELClass) base).getKlass();
String methodName = (String) method;
if ("<init>".equals(methodName)) {
Constructor<?> match = Util.findConstructor(context, clazz, paramTypes, params);
Object[] parameters =
Util.buildParameters(context, match.getParameterTypes(), match.isVarArgs(), params);
Object result = null;
try {
result = match.newInstance(parameters);
} catch (InvocationTargetException e) {
Throwable cause = e.getCause();
Util.handleThrowable(cause);
throw new ELException(cause);
} catch (ReflectiveOperationException e) {
throw new ELException(e);
}
return result;
} else {
// Static method so base should be null
Method match = Util.findMethod(context, clazz, null, methodName, paramTypes, params);
// Note: On Java 9 and above, the isStatic check becomes
// unnecessary because the canAccess() call in Util.findMethod()
// effectively performs the same check
if (match == null || !Modifier.isStatic(match.getModifiers())) {
throw new MethodNotFoundException(
Util.message(context, "staticFieldELResolver.methodNotFound", methodName, clazz.getName()));
}
Object[] parameters =
Util.buildParameters(context, match.getParameterTypes(), match.isVarArgs(), params);
Object result = null;
try {
result = match.invoke(null, parameters);
} catch (IllegalArgumentException | IllegalAccessException e) {
throw new ELException(e);
} catch (InvocationTargetException e) {
Throwable cause = e.getCause();
Util.handleThrowable(cause);
throw new ELException(cause);
}
return result;
}
}
return null;
}
@Override
public Class<?> getType(ELContext context, Object base, Object property) {
Objects.requireNonNull(context);
if (base instanceof ELClass && property instanceof String) {
context.setPropertyResolved(base, property);
Class<?> clazz = ((ELClass) base).getKlass();
String name = (String) property;
Exception exception = null;
try {
Field field = clazz.getField(name);
int modifiers = field.getModifiers();
JreCompat jreCompat = JreCompat.getInstance();
if (Modifier.isStatic(modifiers) && Modifier.isPublic(modifiers) && jreCompat.canAccess(null, field)) {
return field.getType();
}
} catch (IllegalArgumentException | NoSuchFieldException | SecurityException e) {
exception = e;
}
String msg = Util.message(context, "staticFieldELResolver.notFound", name, clazz.getName());
if (exception == null) {
throw new PropertyNotFoundException(msg);
} else {
throw new PropertyNotFoundException(msg, exception);
}
}
return null;
}
@Override
public boolean isReadOnly(ELContext context, Object base, Object property) {
Objects.requireNonNull(context);
if (base instanceof ELClass && property instanceof String) {
context.setPropertyResolved(base, property);
}
return true;
}
/**
* Always returns <code>null</code>.
*/
@Override
public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base) {
return null;
}
/**
* @return This resolver always returns <code>String.class</code>
*/
@Override
public Class<?> getCommonPropertyType(ELContext context, Object base) {
return String.class;
}
}
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