org.apache.myfaces.shared_tomahawk.util.ClassUtils Maven / Gradle / Ivy
The newest version!
/*
* 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.myfaces.shared_tomahawk.util;
import javax.el.ExpressionFactory;
import javax.faces.FacesException;
import javax.faces.context.FacesContext;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
public final class ClassUtils
{
//~ Static fields/initializers -----------------------------------------------------------------
//private static final Log log = LogFactory.getLog(ClassUtils.class);
private static final Logger log = Logger.getLogger(ClassUtils.class.getName());
public static final Class BOOLEAN_ARRAY_CLASS = boolean[].class;
public static final Class BYTE_ARRAY_CLASS = byte[].class;
public static final Class CHAR_ARRAY_CLASS = char[].class;
public static final Class SHORT_ARRAY_CLASS = short[].class;
public static final Class INT_ARRAY_CLASS = int[].class;
public static final Class LONG_ARRAY_CLASS = long[].class;
public static final Class FLOAT_ARRAY_CLASS = float[].class;
public static final Class DOUBLE_ARRAY_CLASS = double[].class;
public static final Class OBJECT_ARRAY_CLASS = Object[].class;
public static final Class BOOLEAN_OBJECT_ARRAY_CLASS = Boolean[].class;
public static final Class BYTE_OBJECT_ARRAY_CLASS = Byte[].class;
public static final Class CHARACTER_OBJECT_ARRAY_CLASS = Character[].class;
public static final Class SHORT_OBJECT_ARRAY_CLASS = Short[].class;
public static final Class INTEGER_OBJECT_ARRAY_CLASS = Integer[].class;
public static final Class LONG_OBJECT_ARRAY_CLASS = Long[].class;
public static final Class FLOAT_OBJECT_ARRAY_CLASS = Float[].class;
public static final Class DOUBLE_OBJECT_ARRAY_CLASS = Double[].class;
public static final Class STRING_OBJECT_ARRAY_CLASS = String[].class;
public static ClassLoaderExtension [] classLoadingExtensions = new ClassLoaderExtension[0];
public static final Map COMMON_TYPES = new HashMap(64);
static
{
COMMON_TYPES.put("byte", Byte.TYPE);
COMMON_TYPES.put("char", Character.TYPE);
COMMON_TYPES.put("double", Double.TYPE);
COMMON_TYPES.put("float", Float.TYPE);
COMMON_TYPES.put("int", Integer.TYPE);
COMMON_TYPES.put("long", Long.TYPE);
COMMON_TYPES.put("short", Short.TYPE);
COMMON_TYPES.put("boolean", Boolean.TYPE);
COMMON_TYPES.put("void", Void.TYPE);
COMMON_TYPES.put("java.lang.Object", Object.class);
COMMON_TYPES.put("java.lang.Boolean", Boolean.class);
COMMON_TYPES.put("java.lang.Byte", Byte.class);
COMMON_TYPES.put("java.lang.Character", Character.class);
COMMON_TYPES.put("java.lang.Short", Short.class);
COMMON_TYPES.put("java.lang.Integer", Integer.class);
COMMON_TYPES.put("java.lang.Long", Long.class);
COMMON_TYPES.put("java.lang.Float", Float.class);
COMMON_TYPES.put("java.lang.Double", Double.class);
COMMON_TYPES.put("java.lang.String", String.class);
COMMON_TYPES.put("byte[]", BYTE_ARRAY_CLASS);
COMMON_TYPES.put("char[]", CHAR_ARRAY_CLASS);
COMMON_TYPES.put("double[]", DOUBLE_ARRAY_CLASS);
COMMON_TYPES.put("float[]", FLOAT_ARRAY_CLASS);
COMMON_TYPES.put("int[]", INT_ARRAY_CLASS);
COMMON_TYPES.put("long[]", LONG_ARRAY_CLASS);
COMMON_TYPES.put("short[]", SHORT_ARRAY_CLASS);
COMMON_TYPES.put("boolean[]", BOOLEAN_ARRAY_CLASS);
COMMON_TYPES.put("java.lang.Object[]", OBJECT_ARRAY_CLASS);
COMMON_TYPES.put("java.lang.Boolean[]", BOOLEAN_OBJECT_ARRAY_CLASS);
COMMON_TYPES.put("java.lang.Byte[]", BYTE_OBJECT_ARRAY_CLASS);
COMMON_TYPES.put("java.lang.Character[]", CHARACTER_OBJECT_ARRAY_CLASS);
COMMON_TYPES.put("java.lang.Short[]", SHORT_OBJECT_ARRAY_CLASS);
COMMON_TYPES.put("java.lang.Integer[]", INTEGER_OBJECT_ARRAY_CLASS);
COMMON_TYPES.put("java.lang.Long[]", LONG_OBJECT_ARRAY_CLASS);
COMMON_TYPES.put("java.lang.Float[]", FLOAT_OBJECT_ARRAY_CLASS);
COMMON_TYPES.put("java.lang.Double[]", DOUBLE_OBJECT_ARRAY_CLASS);
COMMON_TYPES.put("java.lang.String[]", STRING_OBJECT_ARRAY_CLASS);
// array of void is not a valid type
}
/** utility class, do not instantiate */
private ClassUtils()
{
// utility class, disable instantiation
}
//~ Methods ------------------------------------------------------------------------------------
public synchronized static void addClassLoadingExtension(ClassLoaderExtension extension, boolean top)
{
/**
* now at the first look this looks somewhat strange
* but to get the best performance access we assign new native
* arrays to our static variable
*
* we have to synchronized nevertheless because if two threads try to register
* loaders at the same time none of them should get lost
*/
ClassLoaderExtension [] retVal = new ClassLoaderExtension[classLoadingExtensions.length+1];
ArrayList extensions = new ArrayList(classLoadingExtensions.length+1);
if(!top)
{
extensions.addAll(Arrays.asList(classLoadingExtensions));
}
extensions.add(extension);
if(top)
{
extensions.addAll(Arrays.asList(classLoadingExtensions));
}
classLoadingExtensions = (ClassLoaderExtension []) extensions.toArray(retVal);
}
/**
* Tries a Class.loadClass with the context class loader of the current thread first and
* automatically falls back to the ClassUtils class loader (i.e. the loader of the
* myfaces.jar lib) if necessary.
*
* @param type fully qualified name of a non-primitive non-array class
* @return the corresponding Class
* @throws NullPointerException if type is null
* @throws ClassNotFoundException
*/
public static Class classForName(String type)
throws ClassNotFoundException
{
//we now assign the array to safekeep the reference on
// the local variable stack, that way
//we can avoid synchronisation calls
ClassLoaderExtension [] loaderPlugins = classLoadingExtensions;
int plugins = loaderPlugins.length;
for(int cnt = 0; cnt < loaderPlugins.length; cnt ++)
{
ClassLoaderExtension extension = loaderPlugins[cnt];
Class retVal = extension.forName(type);
if(retVal != null)
{
return retVal;
}
}
if (type == null)
{
throw new NullPointerException("type");
}
try
{
// Try WebApp ClassLoader first
return Class.forName(type,
false, // do not initialize for faster startup
getContextClassLoader());
}
catch (ClassNotFoundException ignore)
{
// fallback: Try ClassLoader for ClassUtils (i.e. the myfaces.jar lib)
return Class.forName(type,
false, // do not initialize for faster startup
ClassUtils.class.getClassLoader());
}
}
/**
* Same as {@link #classForName(String)}, but throws a RuntimeException
* (FacesException) instead of a ClassNotFoundException.
*
* @return the corresponding Class
* @throws NullPointerException if type is null
* @throws FacesException if class not found
*/
public static Class simpleClassForName(String type)
{
try
{
return classForName(type);
}
catch (ClassNotFoundException e)
{
log.log(Level.SEVERE, "Class " + type + " not found", e);
throw new FacesException(e);
}
}
/**
* Similar as {@link #classForName(String)}, but also supports primitive types
* and arrays as specified for the JavaType element in the JavaServer Faces Config DTD.
*
* @param type fully qualified class name or name of a primitive type, both optionally
* followed by "[]" to indicate an array type
* @return the corresponding Class
* @throws NullPointerException if type is null
* @throws ClassNotFoundException
*/
public static Class javaTypeToClass(String type)
throws ClassNotFoundException
{
if (type == null)
{
throw new NullPointerException("type");
}
// try common types and arrays of common types first
Class clazz = (Class) COMMON_TYPES.get(type);
if (clazz != null)
{
return clazz;
}
int len = type.length();
if (len > 2 && type.charAt(len - 1) == ']' && type.charAt(len - 2) == '[')
{
String componentType = type.substring(0, len - 2);
Class componentTypeClass = classForName(componentType);
return Array.newInstance(componentTypeClass, 0).getClass();
}
return classForName(type);
}
/**
* This method is similar to shared ClassUtils.javaTypeToClass,
* but the default package for the type is java.lang
*
* @param type
* @return
* @throws ClassNotFoundException
*/
public static Class javaDefaultTypeToClass(String type)
throws ClassNotFoundException
{
if (type == null)
{
throw new NullPointerException("type");
}
// try common types and arrays of common types first
Class clazz = (Class) ClassUtils.COMMON_TYPES.get(type);
if (clazz != null)
{
return clazz;
}
int len = type.length();
if (len > 2 && type.charAt(len - 1) == ']' && type.charAt(len - 2) == '[')
{
String componentType = type.substring(0, len - 2);
Class componentTypeClass = ClassUtils.classForName(componentType);
return Array.newInstance(componentTypeClass, 0).getClass();
}
if (type.indexOf('.') == -1)
{
type = "java.lang." + type;
}
return ClassUtils.classForName(type);
}
/**
* Same as {@link #javaTypeToClass(String)}, but throws a RuntimeException
* (FacesException) instead of a ClassNotFoundException.
*
* @return the corresponding Class
* @throws NullPointerException if type is null
* @throws FacesException if class not found
*/
public static Class simpleJavaTypeToClass(String type)
{
try
{
return javaTypeToClass(type);
}
catch (ClassNotFoundException e)
{
log.log(Level.SEVERE, "Class " + type + " not found", e);
throw new FacesException(e);
}
}
public static URL getResource(String resource)
{
URL url = getContextClassLoader().getResource(resource);
if (url == null)
{
url = ClassUtils.class.getClassLoader().getResource(resource);
}
return url;
}
public static InputStream getResourceAsStream(String resource)
{
InputStream stream = getContextClassLoader()
.getResourceAsStream(resource);
if (stream == null)
{
// fallback
stream = ClassUtils.class.getClassLoader().getResourceAsStream(resource);
}
return stream;
}
/**
* @param resource Name of resource(s) to find in classpath
* @param defaultObject The default object to use to determine the class loader
* (if none associated with current thread.)
* @return Iterator over URL Objects
*/
public static Iterator getResources(String resource, Object defaultObject)
{
try
{
Enumeration resources = getCurrentLoader(defaultObject).getResources(resource);
List lst = new ArrayList();
while (resources.hasMoreElements())
{
lst.add(resources.nextElement());
}
return lst.iterator();
}
catch (IOException e)
{
log.log(Level.SEVERE, e.getMessage(), e);
throw new FacesException(e);
}
}
public static Object newInstance(String type)
throws FacesException
{
if (type == null)
{
return null;
}
return newInstance(simpleClassForName(type));
}
public static Object newInstance(String type, Class expectedType) throws FacesException
{
return newInstance(type, expectedType == null ? null : new Class[] {expectedType});
}
public static Object newInstance(String type, Class[] expectedTypes)
{
if (type == null)
{
return null;
}
Class clazzForName = simpleClassForName(type);
if(expectedTypes != null)
{
for (int i = 0, size = expectedTypes.length; i < size; i++)
{
if (!expectedTypes[i].isAssignableFrom(clazzForName))
{
throw new FacesException("'" + type + "' does not implement expected type '" + expectedTypes[i]
+ "'");
}
}
}
return newInstance(clazzForName);
}
public static T newInstance(Class clazz)
throws FacesException
{
try
{
return clazz.newInstance();
}
catch(NoClassDefFoundError e)
{
log.log(Level.SEVERE, "Class : "+clazz.getName()+" not found.",e);
throw new FacesException(e);
}
catch (InstantiationException e)
{
log.log(Level.SEVERE, e.getMessage(), e);
throw new FacesException(e);
}
catch (IllegalAccessException e)
{
log.log(Level.SEVERE, e.getMessage(), e);
throw new FacesException(e);
}
}
public static T newInstance(Class clazz,
Class[] constructorArgClasses,
Object... constructorArgs) throws NoSuchMethodException
{
if (constructorArgs.length == 0)
{
// no args given - use normal newInstance()
return newInstance(clazz);
}
// try to get a fitting constructor (throws NoSuchMethodException)
Constructor constructor = clazz.getConstructor(constructorArgClasses);
try
{
// actually create instance
return (T) constructor.newInstance(constructorArgs);
}
catch (Exception e)
{
throw new FacesException(e);
}
}
public static Object convertToType(Object value, Class desiredClass)
{
if (value == null)
{
return null;
}
try
{
ExpressionFactory expFactory = FacesContext.getCurrentInstance().getApplication().getExpressionFactory();
return expFactory.coerceToType(value, desiredClass);
}
catch (Exception e)
{
String message = "Cannot coerce " + value.getClass().getName()
+ " to " + desiredClass.getName();
log.log(Level.SEVERE, message, e);
throw new FacesException(message, e);
}
}
/**
* Gets the ClassLoader associated with the current thread. Returns the class loader associated with
* the specified default object if no context loader is associated with the current thread.
*
* @param defaultObject The default object to use to determine the class loader
* (if none associated with current thread.)
* @return ClassLoader
*/
protected static ClassLoader getCurrentLoader(Object defaultObject)
{
ClassLoader loader = getContextClassLoader();
if(loader == null)
{
loader = defaultObject.getClass().getClassLoader();
}
return loader;
}
/**
* Gets the ClassLoader associated with the current thread. Includes a check for priviledges
* against java2 security to ensure no security related exceptions are encountered.
*
* @since 3.0.6
* @return ClassLoader
*/
public static ClassLoader getContextClassLoader()
{
// call into the same method on ClassLoaderUtils. no need for duplicate code maintenance.
return ClassLoaderUtils.getContextClassLoader();
}
/**
* Creates ApplicationObjects like NavigationHandler or StateManager and creates
* the right wrapping chain of the ApplicationObjects known as the decorator pattern.
* @param
* @param interfaceClass The class from which the implementation has to inherit from.
* @param classNamesIterator All the class names of the actual ApplicationObject implementations
* from the faces-config.xml.
* @param defaultObject The default implementation for the given ApplicationObject.
* @return
*/
public static T buildApplicationObject(Class interfaceClass,
Collection classNamesIterator, T defaultObject)
{
return buildApplicationObject(interfaceClass, null, null, classNamesIterator, defaultObject);
}
/**
* Creates ApplicationObjects like NavigationHandler or StateManager and creates
* the right wrapping chain of the ApplicationObjects known as the decorator pattern.
* @param
* @param interfaceClass The class from which the implementation has to inherit from.
* @param extendedInterfaceClass A subclass of interfaceClass which specifies a more
* detailed implementation.
* @param extendedInterfaceWrapperClass A wrapper class for the case that you have an ApplicationObject
* which only implements the interfaceClass but not the
* extendedInterfaceClass.
* @param classNamesIterator All the class names of the actual ApplicationObject implementations
* from the faces-config.xml.
* @param defaultObject The default implementation for the given ApplicationObject.
* @return
*/
@SuppressWarnings("unchecked")
public static T buildApplicationObject(Class interfaceClass, Class extendedInterfaceClass,
Class extendedInterfaceWrapperClass,
Collection classNamesIterator, T defaultObject)
{
T current = defaultObject;
for (String implClassName : classNamesIterator)
{
Class implClass = ClassUtils.simpleClassForName(implClassName);
// check, if class is of expected interface type
if (!interfaceClass.isAssignableFrom(implClass))
{
throw new IllegalArgumentException("Class " + implClassName + " is no " + interfaceClass.getName());
}
if (current == null)
{
// nothing to decorate
current = (T) ClassUtils.newInstance(implClass);
}
else
{
// let's check if class supports the decorator pattern
T newCurrent = null;
try
{
Constructor delegationConstructor = null;
// first, if there is a extendedInterfaceClass,
// try to find a constructor that uses that
if (extendedInterfaceClass != null
&& extendedInterfaceClass.isAssignableFrom(current.getClass()))
{
try
{
delegationConstructor =
implClass.getConstructor(new Class[] {extendedInterfaceClass});
}
catch (NoSuchMethodException mnfe)
{
// just eat it
}
}
if (delegationConstructor == null)
{
// try to find the constructor with the "normal" interfaceClass
delegationConstructor =
implClass.getConstructor(new Class[] {interfaceClass});
}
// impl class supports decorator pattern at this point
try
{
// create new decorator wrapping current
newCurrent = delegationConstructor.newInstance(new Object[] { current });
}
catch (InstantiationException e)
{
log.log(Level.SEVERE, e.getMessage(), e);
throw new FacesException(e);
}
catch (IllegalAccessException e)
{
log.log(Level.SEVERE, e.getMessage(), e);
throw new FacesException(e);
}
catch (InvocationTargetException e)
{
log.log(Level.SEVERE, e.getMessage(), e);
throw new FacesException(e);
}
}
catch (NoSuchMethodException e)
{
// no decorator pattern support
newCurrent = (T) ClassUtils.newInstance(implClass);
}
// now we have a new current object (newCurrent)
// --> find out if it is assignable from extendedInterfaceClass
// and if not, wrap it in a backwards compatible wrapper (if available)
if (extendedInterfaceWrapperClass != null
&& !extendedInterfaceClass.isAssignableFrom(newCurrent.getClass()))
{
try
{
Constructor wrapperConstructor
= extendedInterfaceWrapperClass.getConstructor(
new Class[] {interfaceClass, extendedInterfaceClass});
newCurrent = wrapperConstructor.newInstance(new Object[] {newCurrent, current});
}
catch (NoSuchMethodException e)
{
log.log(Level.SEVERE, e.getMessage(), e);
throw new FacesException(e);
}
catch (InstantiationException e)
{
log.log(Level.SEVERE, e.getMessage(), e);
throw new FacesException(e);
}
catch (IllegalAccessException e)
{
log.log(Level.SEVERE, e.getMessage(), e);
throw new FacesException(e);
}
catch (InvocationTargetException e)
{
log.log(Level.SEVERE, e.getMessage(), e);
throw new FacesException(e);
}
}
current = newCurrent;
}
}
return current;
}
}