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.lang.reflect.Modifier;
import java.security.AccessController;
import java.security.PrivilegedAction;
import org.apache.catalina.Context;
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 final 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.
*
* @param setter The setter method
*
* @return the bean property name
*/
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;
}
/**
* Determines if a method is a valid lifecycle callback method.
*
* @param method The method to test
*
* @return true if the method is a valid lifecycle callback method, else false
*/
public static boolean isValidLifecycleCallback(Method method) {
if (method.getParameterTypes().length != 0 || Modifier.isStatic(method.getModifiers()) ||
method.getExceptionTypes().length > 0 || !method.getReturnType().getName().equals("void")) {
return false;
}
return true;
}
/**
* Obtain the declared fields for a class taking account of any security manager that may be configured.
*
* @param clazz The class to introspect
*
* @return the class fields as an array
*/
public static Field[] getDeclaredFields(final Class clazz) {
Field[] fields = null;
if (Globals.IS_SECURITY_ENABLED) {
fields = AccessController.doPrivileged((PrivilegedAction) 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.
*
* @param clazz The class to introspect
*
* @return the class methods as an array
*/
public static Method[] getDeclaredMethods(final Class clazz) {
Method[] methods = null;
if (Globals.IS_SECURITY_ENABLED) {
methods = AccessController.doPrivileged((PrivilegedAction) 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.
*
* @param context The class loader of this context will be used to attempt to load the class
* @param className The class name
*
* @return the loaded class or null if loading failed
*/
public static Class loadClass(Context context, String className) {
ClassLoader cl = context.getLoader().getClassLoader();
Log log = context.getLogger();
Class clazz = null;
try {
clazz = cl.loadClass(className);
} catch (ClassNotFoundException | NoClassDefFoundError | ClassFormatError e) {
log.debug(sm.getString("introspection.classLoadFailed", className), e);
} catch (Throwable t) {
ExceptionUtils.handleThrowable(t);
log.debug(sm.getString("introspection.classLoadFailed", className), t);
}
return clazz;
}
/**
* Converts the primitive type to its corresponding wrapper.
*
* @param clazz Class that will be evaluated
*
* @return if the parameter is a primitive type returns its wrapper; otherwise returns the same class
*/
public static Class convertPrimitiveType(Class clazz) {
if (clazz.equals(char.class)) {
return Character.class;
} else if (clazz.equals(int.class)) {
return Integer.class;
} else if (clazz.equals(boolean.class)) {
return Boolean.class;
} else if (clazz.equals(double.class)) {
return Double.class;
} else if (clazz.equals(byte.class)) {
return Byte.class;
} else if (clazz.equals(short.class)) {
return Short.class;
} else if (clazz.equals(long.class)) {
return Long.class;
} else if (clazz.equals(float.class)) {
return Float.class;
} else {
return clazz;
}
}
}