com.opensymphony.xwork.ObjectFactory Maven / Gradle / Ivy
/*
* Copyright (c) 2002-2006 by OpenSymphony
* All rights reserved.
*/
package com.opensymphony.xwork;
import com.opensymphony.util.ClassLoaderUtil;
import com.opensymphony.xwork.config.ConfigurationException;
import com.opensymphony.xwork.config.entities.ActionConfig;
import com.opensymphony.xwork.config.entities.InterceptorConfig;
import com.opensymphony.xwork.config.entities.ResultConfig;
import com.opensymphony.xwork.interceptor.Interceptor;
import com.opensymphony.xwork.util.OgnlUtil;
import com.opensymphony.xwork.util.XWorkContinuationConfig;
import com.opensymphony.xwork.validator.Validator;
import com.uwyn.rife.continuations.ContinuationConfig;
import com.uwyn.rife.continuations.ContinuationInstrumentor;
import com.uwyn.rife.continuations.util.ClassByteUtil;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* ObjectFactory is responsible for building the core framework objects. Users may register their own implementation of
* the ObjectFactory to control instantiation of these Objects.
*
* This default implementation uses the {@link #buildBean(Class,java.util.Map) buildBean} method to create all classes
* (interceptors, actions, results, etc).
*
* @author Jason Carreira
*/
public class ObjectFactory {
private static final Log LOG = LogFactory.getLog(ObjectFactory.class);
private static ContinuationsClassLoader ccl;
private static ObjectFactory FACTORY = new ObjectFactory();
private static String continuationPackage;
public static void setContinuationPackage(String continuationPackage) {
ContinuationConfig.setInstance(new XWorkContinuationConfig());
ObjectFactory.continuationPackage = continuationPackage;
ObjectFactory.ccl = new ContinuationsClassLoader(continuationPackage, Thread.currentThread().getContextClassLoader());
}
public static String getContinuationPackage() {
return continuationPackage;
}
protected ObjectFactory() {
}
public static void setObjectFactory(ObjectFactory factory) {
FACTORY = factory;
}
public static ObjectFactory getObjectFactory() {
return FACTORY;
}
/**
* Allows for ObjectFactory implementations that support
* Actions without no-arg constructors.
*
* @return true if no-arg constructor is required, false otherwise
*/
public boolean isNoArgConstructorRequired() {
return true;
}
/**
* Utility method to obtain the class matched to className. Caches look ups so that subsequent
* lookups will be faster.
*
* @param className The fully qualified name of the class to return
* @return The class itself
* @throws ClassNotFoundException
*/
public Class getClassInstance(String className) throws ClassNotFoundException {
if (ccl != null) {
return ccl.loadClass(className);
}
return ClassLoaderUtil.loadClass(className, this.getClass());
}
/**
* Build an instance of the action class to handle a web request
* @param actionName the name the action configuration is set up with in the configuration
* @param namespace the namespace the action is configured in
* @param config the action configuration found in the config for the actionName / namespace
* @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork.ActionContext}
* @return instance of the action class to handle a web request
* @throws Exception
*/
public Object buildAction(String actionName, String namespace, ActionConfig config, Map extraContext) throws Exception {
return buildBean(config.getClassName(), extraContext);
}
/**
* Build a generic Java object of the given type.
*
* @param clazz the type of Object to build
* @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork.ActionContext}
*/
public Object buildBean(Class clazz, Map extraContext) throws Exception {
return clazz.newInstance();
}
/**
* Build a generic Java object of the given type.
*
* @param className the type of Object to build
* @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork.ActionContext}
*/
public Object buildBean(String className, Map extraContext) throws Exception {
Class clazz = getClassInstance(className);
return buildBean(clazz, extraContext);
}
/**
* Builds an Interceptor from the InterceptorConfig and the Map of
* parameters from the interceptor reference. Implementations of this method
* should ensure that the Interceptor is parameterized with both the
* parameters from the Interceptor config and the interceptor ref Map (the
* interceptor ref params take precedence), and that the Interceptor.init()
* method is called on the Interceptor instance before it is returned.
*
* @param interceptorConfig the InterceptorConfig from the configuration
* @param interceptorRefParams a Map of params provided in the Interceptor reference in the
* Action mapping or InterceptorStack definition
*/
public Interceptor buildInterceptor(InterceptorConfig interceptorConfig, Map interceptorRefParams) throws ConfigurationException {
String interceptorClassName = interceptorConfig.getClassName();
Map thisInterceptorClassParams = interceptorConfig.getParams();
Map params = (thisInterceptorClassParams == null) ? new HashMap() : new HashMap(thisInterceptorClassParams);
params.putAll(interceptorRefParams);
String message;
Throwable cause;
try {
// interceptor instances are long-lived and used across user sessions, so don't try to pass in any extra context
Interceptor interceptor = (Interceptor) buildBean(interceptorClassName, null);
OgnlUtil.setProperties(params, interceptor);
interceptor.init();
return interceptor;
} catch (InstantiationException e) {
cause = e;
message = "Unable to instantiate an instance of Interceptor class [" + interceptorClassName + "].";
} catch (IllegalAccessException e) {
cause = e;
message = "IllegalAccessException while attempting to instantiate an instance of Interceptor class [" + interceptorClassName + "].";
} catch (ClassCastException e) {
cause = e;
message = "Class [" + interceptorClassName + "] does not implement com.opensymphony.xwork.interceptor.Interceptor";
} catch (Exception e) {
cause = e;
message = "Caught Exception while registering Interceptor class " + interceptorClassName;
} catch (NoClassDefFoundError e) {
cause = e;
message = "Could not load class " + interceptorClassName + ". Perhaps it exists but certain dependencies are not available?";
}
throw new ConfigurationException(message, cause, interceptorConfig);
}
/**
* Build a Result using the type in the ResultConfig and set the parameters in the ResultConfig.
*
* @param resultConfig the ResultConfig found for the action with the result code returned
* @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork.ActionContext}
*/
public Result buildResult(ResultConfig resultConfig, Map extraContext) throws Exception {
String resultClassName = resultConfig.getClassName();
Result result = null;
if (resultClassName != null) {
result = (Result) buildBean(resultClassName, extraContext);
OgnlUtil.setProperties(resultConfig.getParams(), result, extraContext);
}
return result;
}
/**
* Build a Validator of the given type and set the parameters on it
*
* @param className the type of Validator to build
* @param params property name -> value Map to set onto the Validator instance
* @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork.ActionContext}
*/
public Validator buildValidator(String className, Map params, Map extraContext) throws Exception {
Validator validator = (Validator) buildBean(className, null);
OgnlUtil.setProperties(params, validator);
return validator;
}
static class ContinuationsClassLoader extends ClassLoader {
private String base;
private ClassLoader parent;
public ContinuationsClassLoader(String base, ClassLoader parent) {
super(parent);
this.base = base;
this.parent = parent;
}
public Class loadClass(String name) throws ClassNotFoundException {
if (validName(name)) {
Class clazz = findLoadedClass(name);
if (clazz == null) {
try {
byte[] bytes = ClassByteUtil.getBytes(name, parent);
if (bytes == null) {
throw new XworkException("Continuation error: no bytes loaded");
}
byte[] resume_bytes = null;
try {
resume_bytes = ContinuationInstrumentor.instrument(bytes, name, false);
} catch (ClassNotFoundException e) {
// this can happen when the Rife Continuations code gets broken (there are bugs in it still, ya know!)
// rather than making a big deal, we'll quietly log this and move on
// when more people are using continuations, perhaps we'll raise the log level
LOG.debug("Error instrumenting with RIFE/Continuations, " +
"loading class normally without continuation support", e);
}
if (resume_bytes == null) {
return parent.loadClass(name);
} else {
return defineClass(name, resume_bytes, 0, resume_bytes.length);
}
} catch (IOException e) {
throw new XworkException("Continuation error", e);
}
} else {
return clazz;
}
} else {
return parent.loadClass(name);
}
}
private boolean validName(String name) {
return name.startsWith(base + ".");
}
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy