org.apache.catalina.util.Introspection 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.catalina.util;
import java.beans.Introspector;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.security.AccessController;
import java.security.PrivilegedAction;
import org.apache.catalina.Container;
import org.apache.catalina.Globals;
import org.apache.juli.logging.Log;
import org.apache.tomcat.util.ExceptionUtils;
import org.apache.tomcat.util.res.StringManager;
/**
* Provides introspection utilities that either require knowledge of Tomcat
* internals or are solely used by Tomcat internals.
*/
public class Introspection {
private static StringManager sm =
StringManager.getManager("org.apache.catalina.util");
/**
* Extract the Java Bean property name from the setter name.
*
* Note: This method assumes that the method name has already been checked
* for correctness.
*/
public static String getPropertyName(Method setter) {
return Introspector.decapitalize(setter.getName().substring(3));
}
/**
* Determines if a method has a valid name and signature for a Java Bean
* setter.
*
* @param method The method to test
*
* @return true if the method does have a valid name and
* signature, else false
*/
public static boolean isValidSetter(Method method) {
if (method.getName().startsWith("set")
&& method.getName().length() > 3
&& method.getParameterTypes().length == 1
&& method.getReturnType().getName().equals("void")) {
return true;
}
return false;
}
/**
* Obtain the declared fields for a class taking account of any security
* manager that may be configured.
*/
public static Field[] getDeclaredFields(final Class clazz) {
Field[] fields = null;
if (Globals.IS_SECURITY_ENABLED) {
fields = AccessController.doPrivileged(
new PrivilegedAction(){
@Override
public Field[] run(){
return clazz.getDeclaredFields();
}
});
} else {
fields = clazz.getDeclaredFields();
}
return fields;
}
/**
* Obtain the declared methods for a class taking account of any security
* manager that may be configured.
*/
public static Method[] getDeclaredMethods(final Class clazz) {
Method[] methods = null;
if (Globals.IS_SECURITY_ENABLED) {
methods = AccessController.doPrivileged(
new PrivilegedAction(){
@Override
public Method[] run(){
return clazz.getDeclaredMethods();
}
});
} else {
methods = clazz.getDeclaredMethods();
}
return methods;
}
/**
* Attempt to load a class using the given Container's class loader. If the
* class cannot be loaded, a debug level log message will be written to the
* Container's log and null will be returned.
*/
public static Class loadClass(Container container, String className) {
ClassLoader cl = container.getLoader().getClassLoader();
Log log = container.getLogger();
Class clazz = null;
try {
clazz = cl.loadClass(className);
} catch (ClassNotFoundException e) {
log.debug(sm.getString("introspection.classLoadFailed"), e);
} catch (NoClassDefFoundError e) {
log.debug(sm.getString("introspection.classLoadFailed"), e);
} catch (ClassFormatError e) {
log.debug(sm.getString("introspection.classLoadFailed"), e);
} catch (Throwable t) {
ExceptionUtils.handleThrowable(t);
log.debug(sm.getString("introspection.classLoadFailed"), t);
}
return clazz;
}
}