/*
* Copyright 2002-2010 the original author or authors.
*
* Licensed 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.springframework.jndi;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import javax.naming.Context;
import javax.naming.NamingException;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.util.ClassUtils;
/**
* {@link org.springframework.beans.factory.FactoryBean} that looks up a
* JNDI object. Exposes the object found in JNDI for bean references,
* e.g. for data access object's "dataSource" property in case of a
* {@link javax.sql.DataSource}.
*
* <p>The typical usage will be to register this as singleton factory
* (e.g. for a certain JNDI-bound DataSource) in an application context,
* and give bean references to application services that need it.
*
* <p>The default behavior is to look up the JNDI object on startup and cache it.
* This can be customized through the "lookupOnStartup" and "cache" properties,
* using a {@link JndiObjectTargetSource} underneath. Note that you need to specify
* a "proxyInterface" in such a scenario, since the actual JNDI object type is not
* known in advance.
*
* <p>Of course, bean classes in a Spring environment may lookup e.g. a DataSource
* from JNDI themselves. This class simply enables central configuration of the
* JNDI name, and easy switching to non-JNDI alternatives. The latter is
* particularly convenient for test setups, reuse in standalone clients, etc.
*
* <p>Note that switching to e.g. DriverManagerDataSource is just a matter of
* configuration: Simply replace the definition of this FactoryBean with a
* {@link org.springframework.jdbc.datasource.DriverManagerDataSource} definition!
*
* @author Juergen Hoeller
* @since 22.05.2003
* @see #setProxyInterface
* @see #setLookupOnStartup
* @see #setCache
* @see JndiObjectTargetSource
*/
public class JndiObjectFactoryBean extends JndiObjectLocator implements FactoryBean<Object>, BeanClassLoaderAware {
private Class[] proxyInterfaces;
private boolean lookupOnStartup = true;
private boolean cache = true;
private boolean exposeAccessContext = false;
private Object defaultObject;
private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();
private Object jndiObject;
/**
* Specify the proxy interface to use for the JNDI object.
* <p>Typically used in conjunction with "lookupOnStartup"=false and/or "cache"=false.
* Needs to be specified because the actual JNDI object type is not known
* in advance in case of a lazy lookup.
* @see #setProxyInterfaces
* @see #setLookupOnStartup
* @see #setCache
*/
public void setProxyInterface(Class proxyInterface) {
this.proxyInterfaces = new Class[] {proxyInterface};
}
/**
* Specify multiple proxy interfaces to use for the JNDI object.
* <p>Typically used in conjunction with "lookupOnStartup"=false and/or "cache"=false.
* Note that proxy interfaces will be autodetected from a specified "expectedType",
* if necessary.
* @see #setExpectedType
* @see #setLookupOnStartup
* @see #setCache
*/
public void setProxyInterfaces(Class[] proxyInterfaces) {
this.proxyInterfaces = proxyInterfaces;
}
/**
* Set whether to look up the JNDI object on startup. Default is "true".
* <p>Can be turned off to allow for late availability of the JNDI object.
* In this case, the JNDI object will be fetched on first access.
* <p>For a lazy lookup, a proxy interface needs to be specified.
* @see #setProxyInterface
* @see #setCache
*/
public void setLookupOnStartup(boolean lookupOnStartup) {
this.lookupOnStartup = lookupOnStartup;
}
/**
* Set whether to cache the JNDI object once it has been located.
* Default is "true".
* <p>Can be turned off to allow for hot redeployment of JNDI objects.
* In this case, the JNDI object will be fetched for each invocation.
* <p>For hot redeployment, a proxy interface needs to be specified.
* @see #setProxyInterface
* @see #setLookupOnStartup
*/
public void setCache(boolean cache) {
this.cache = cache;
}
/**
* Set whether to expose the JNDI environment context for all access to the target
* object, i.e. for all method invocations on the exposed object reference.
* <p>Default is "false", i.e. to only expose the JNDI context for object lookup.
* Switch this flag to "true" in order to expose the JNDI environment (including
* the authorization context) for each method invocation, as needed by WebLogic
* for JNDI-obtained factories (e.g. JDBC DataSource, JMS ConnectionFactory)
* with authorization requirements.
*/
public void setExposeAccessContext(boolean exposeAccessContext) {
this.exposeAccessContext = exposeAccessContext;
}
/**
* Specify a default object to fall back to if the JNDI lookup fails.
* Default is none.
* <p>This can be an arbitrary bean reference or literal value.
* It is typically used for literal values in scenarios where the JNDI environment
* might define specific config settings but those are not required to be present.
* <p>Note: This is only supported for lookup on startup.
* @see #setLookupOnStartup
*/
public void setDefaultObject(Object defaultObject) {
this.defaultObject = defaultObject;
}
public void setBeanClassLoader(ClassLoader classLoader) {
this.beanClassLoader = classLoader;
}
/**
* Look up the JNDI object and store it.
*/
@Override
public void afterPropertiesSet() throws IllegalArgumentException, NamingException {
super.afterPropertiesSet();
if (this.proxyInterfaces != null || !this.lookupOnStartup || !this.cache || this.exposeAccessContext) {
// We need to create a proxy for this...
if (this.defaultObject != null) {
throw new IllegalArgumentException(
"'defaultObject' is not supported in combination with 'proxyInterface'");
}
// We need a proxy and a JndiObjectTargetSource.
this.jndiObject = JndiObjectProxyFactory.createJndiObjectProxy(this);
}
else {
if (this.defaultObject != null && getExpectedType() != null &&
!getExpectedType().isInstance(this.defaultObject)) {
throw new IllegalArgumentException("Default object [" + this.defaultObject +
"] of type [" + this.defaultObject.getClass().getName() +
"] is not of expected type [" + getExpectedType().getName() + "]");
}
// Locate specified JNDI object.
this.jndiObject = lookupWithFallback();
}
}
/**
* Lookup variant that that returns the specified "defaultObject"
* (if any) in case of lookup failure.
* @return the located object, or the "defaultObject" as fallback
* @throws NamingException in case of lookup failure without fallback
* @see #setDefaultObject
*/
protected Object lookupWithFallback() throws NamingException {
ClassLoader originalClassLoader = ClassUtils.overrideThreadContextClassLoader(this.beanClassLoader);
try {
return lookup();
}
catch (TypeMismatchNamingException ex) {
// Always let TypeMismatchNamingException through -
// we don't want to fall back to the defaultObject in this case.
throw ex;
}
catch (NamingException ex) {
if (this.defaultObject != null) {
if (logger.isDebugEnabled()) {
logger.debug("JNDI lookup failed - returning specified default object instead", ex);
}
else if (logger.isInfoEnabled()) {
logger.info("JNDI lookup failed - returning specified default object instead: " + ex);
}
return this.defaultObject;
}
throw ex;
}
finally {
if (originalClassLoader != null) {
Thread.currentThread().setContextClassLoader(originalClassLoader);
}
}
}
/**
* Return the singleton JNDI object.
*/
public Object getObject() {
return this.jndiObject;
}
public Class<?> getObjectType() {
if (this.proxyInterfaces != null) {
if (this.proxyInterfaces.length == 1) {
return this.proxyInterfaces[0];
}
else if (this.proxyInterfaces.length > 1) {
return createCompositeInterface(this.proxyInterfaces);
}
}
if (this.jndiObject != null) {
return this.jndiObject.getClass();
}
else {
return getExpectedType();
}
}
public boolean isSingleton() {
return true;
}
/**
* Create a composite interface Class for the given interfaces,
* implementing the given interfaces in one single Class.
* <p>The default implementation builds a JDK proxy class for the
* given interfaces.
* @param interfaces the interfaces to merge
* @return the merged interface as Class
* @see java.lang.reflect.Proxy#getProxyClass
*/
protected Class createCompositeInterface(Class[] interfaces) {
return ClassUtils.createCompositeInterface(interfaces, this.beanClassLoader);
}
/**
* Inner class to just introduce an AOP dependency when actually creating a proxy.
*/
private static class JndiObjectProxyFactory {
private static Object createJndiObjectProxy(JndiObjectFactoryBean jof) throws NamingException {
// Create a JndiObjectTargetSource that mirrors the JndiObjectFactoryBean's configuration.
JndiObjectTargetSource targetSource = new JndiObjectTargetSource();
targetSource.setJndiTemplate(jof.getJndiTemplate());
targetSource.setJndiName(jof.getJndiName());
targetSource.setExpectedType(jof.getExpectedType());
targetSource.setResourceRef(jof.isResourceRef());
targetSource.setLookupOnStartup(jof.lookupOnStartup);
targetSource.setCache(jof.cache);
targetSource.afterPropertiesSet();
// Create a proxy with JndiObjectFactoryBean's proxy interface and the JndiObjectTargetSource.
ProxyFactory proxyFactory = new ProxyFactory();
if (jof.proxyInterfaces != null) {
proxyFactory.setInterfaces(jof.proxyInterfaces);
}
else {
Class targetClass = targetSource.getTargetClass();
if (targetClass == null) {
throw new IllegalStateException(
"Cannot deactivate 'lookupOnStartup' without specifying a 'proxyInterface' or 'expectedType'");
}
Class[] ifcs = ClassUtils.getAllInterfacesForClass(targetClass, jof.beanClassLoader);
for (Class ifc : ifcs) {
if (Modifier.isPublic(ifc.getModifiers())) {
proxyFactory.addInterface(ifc);
}
}
}
if (jof.exposeAccessContext) {
proxyFactory.addAdvice(new JndiContextExposingInterceptor(jof.getJndiTemplate()));
}
proxyFactory.setTargetSource(targetSource);
return proxyFactory.getProxy(jof.beanClassLoader);
}
}
/**
* Interceptor that exposes the JNDI context for all method invocations,
* according to JndiObjectFactoryBean's "exposeAccessContext" flag.
*/
private static class JndiContextExposingInterceptor implements MethodInterceptor {
private final JndiTemplate jndiTemplate;
public JndiContextExposingInterceptor(JndiTemplate jndiTemplate) {
this.jndiTemplate = jndiTemplate;
}
public Object invoke(MethodInvocation invocation) throws Throwable {
Context ctx = (isEligible(invocation.getMethod()) ? this.jndiTemplate.getContext() : null);
try {
return invocation.proceed();
}
finally {
this.jndiTemplate.releaseContext(ctx);
}
}
protected boolean isEligible(Method method) {
return !Object.class.equals(method.getDeclaringClass());
}
}
}
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