Merge pull request #312 from cyb3r4nt/jsonrpc4j-issue-303

Remove usage of org.springframework.remoting.support.RemoteExporter #303

Author: briandilley

README.md

@@ -16,7 +16,7 @@ JSON-RPC).
   * HTTP Server (`HttpServletRequest` \ `HttpServletResponse`)
   * Portlet Server (`ResourceRequest` \ `ResourceResponse`)
   * Socket Server (`StreamServer`)
-  * Integration with the Spring Framework (`RemoteExporter`)
+  * Integration with the Spring Framework
   * Streaming client
   * HTTP client
   * Dynamic client proxies
@@ -66,7 +66,7 @@ that take `InputStream`s and `OutputStream`s.  Also in the library is a `JsonRpc
 which extends the `JsonRpcClient` to add HTTP support.
 
 ## Spring Framework
-jsonrpc4j provides a `RemoteExporter` to expose java services as JSON-RPC over HTTP without
+jsonrpc4j provides support for exposing java services as JSON-RPC over HTTP without
 requiring any additional work on the part of the programmer.  The following example explains
 how to use the `JsonServiceExporter` within the Spring Framework.
 
@@ -113,7 +113,9 @@ public class UserServiceImpl
 }
 ```
 
-Configure your service in spring as you would any other RemoteExporter:
+Configure your service in Spring as you would do it for any other Beans,
+and then add a reference of your service Bean into `JsonServiceExporter`
+by specifying the `service` and `serviceInterface` properties:
 
 ```xml
 <?xml version="1.0" encoding="UTF-8"?>

src/main/java/com/googlecode/jsonrpc4j/spring/AbstractCompositeJsonServiceExporter.java

@@ -93,7 +93,7 @@ public final void afterPropertiesSet()
 	 *
 	 * @throws Exception on error
 	 */
-	void exportService()
+	protected void exportService()
 			throws Exception {
 		// no-op
 	}

src/main/java/com/googlecode/jsonrpc4j/spring/AbstractJsonServiceExporter.java

@@ -2,23 +2,25 @@
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.googlecode.jsonrpc4j.*;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.beans.factory.BeanFactoryUtils;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
-import org.springframework.remoting.support.RemoteExporter;
+import org.springframework.util.ClassUtils;
 
 import java.util.List;
 import java.util.concurrent.ExecutorService;
 
 /**
- * {@link RemoteExporter} that exports services using Json
- * according to the JSON-RPC proposal specified at:
- * <a href="http://groups.google.com/group/json-rpc">
- * http://groups.google.com/group/json-rpc</a>.
+ * Exports user defined services using JSON-RPC protocol
  */
 @SuppressWarnings("unused")
-abstract class AbstractJsonServiceExporter extends RemoteExporter implements InitializingBean, ApplicationContextAware {
+abstract class AbstractJsonServiceExporter implements InitializingBean, ApplicationContextAware {
+	private static final Logger logger = LoggerFactory.getLogger(AbstractJsonServiceExporter.class);
 
 	private ObjectMapper objectMapper;
 	private JsonRpcServer jsonRpcServer;
@@ -36,6 +38,8 @@ abstract class AbstractJsonServiceExporter extends RemoteExporter implements Ini
 	private List<JsonRpcInterceptor> interceptorList;
 	private ExecutorService batchExecutorService = null;
 	private long parallelBatchProcessingTimeout;
+	private Object service;
+	private Class<?> serviceInterface;
 
 	/**
 	 * {@inheritDoc}
@@ -49,7 +53,7 @@ public void afterPropertiesSet() throws Exception {
 			try {
 				objectMapper = BeanFactoryUtils.beanOfTypeIncludingAncestors(applicationContext, ObjectMapper.class);
 			} catch (Exception e) {
-				logger.debug(e);
+				logger.debug("Failed to obtain objectMapper from application context", e);
 			}
 		}
 		if (objectMapper == null) {
@@ -93,7 +97,7 @@ public void afterPropertiesSet() throws Exception {
 	 *
 	 * @throws Exception on error
 	 */
-	void exportService()
+	protected void exportService()
 			throws Exception {
 		// no-op
 	}
@@ -214,4 +218,96 @@ public void setBatchExecutorService(ExecutorService batchExecutorService) {
     public void setParallelBatchProcessingTimeout(long parallelBatchProcessingTimeout) {
         this.parallelBatchProcessingTimeout = parallelBatchProcessingTimeout;
     }
+
+	/**
+	 * Set the service to export.
+	 * Typically populated via a bean reference.
+	 */
+	public void setService(Object service) {
+		this.service = service;
+	}
+
+	/**
+	 * Return the service to export.
+	 */
+	public Object getService() {
+		return this.service;
+	}
+
+	/**
+	 * Set the interface of the service to export.
+	 * The interface must be suitable for the particular service and remoting strategy.
+	 */
+	public void setServiceInterface(Class<?> serviceInterface) {
+		if (serviceInterface == null) {
+			throw new IllegalArgumentException("'serviceInterface' must not be null");
+		}
+		if (!serviceInterface.isInterface()) {
+			throw new IllegalArgumentException("'serviceInterface' must be an interface");
+		}
+		this.serviceInterface = serviceInterface;
+	}
+
+	/**
+	 * Return the interface of the service to export.
+	 */
+	public Class<?> getServiceInterface() {
+		return this.serviceInterface;
+	}
+
+
+	/**
+	 * Check whether a service reference has been set,
+	 * and whether it matches the specified service.
+	 * @see #setServiceInterface
+	 * @see #setService
+	 */
+	protected void checkServiceInterface() throws IllegalArgumentException {
+		Class<?> serviceInterface = getServiceInterface();
+		if (serviceInterface == null) {
+			throw new IllegalArgumentException("Property 'serviceInterface' is required");
+		}
+
+		Object service = getService();
+		if (service instanceof String) {
+			throw new IllegalArgumentException(
+				"Service [" + service + "] is a String rather than an actual service reference:"
+					+ " Have you accidentally specified the service bean name as value "
+					+ " instead of as reference?"
+			);
+		}
+		if (!serviceInterface.isInstance(service)) {
+			throw new IllegalArgumentException(
+				"Service interface [" + serviceInterface.getName()
+				+ "] needs to be implemented by service [" + service + "] of class ["
+				+ service.getClass().getName() + "]"
+			);
+		}
+	}
+
+
+	/**
+	 * Get a proxy for the given service object, implementing the specified
+	 * service interface.
+	 * <p>Used to export a proxy that does not expose any internals but just
+	 * a specific interface intended for remote access.
+	 *
+	 * @return the proxy
+	 * @see #setServiceInterface
+	 * @see #setService
+	 */
+	protected Object getProxyForService() {
+		Object targetService = getService();
+		if (targetService == null) {
+			throw new IllegalArgumentException("Property 'service' is required");
+		}
+		checkServiceInterface();
+
+		ProxyFactory proxyFactory = new ProxyFactory();
+		proxyFactory.addInterface(getServiceInterface());
+		proxyFactory.setTarget(targetService);
+		proxyFactory.setOpaque(true);
+
+		return proxyFactory.getProxy(ClassUtils.getDefaultClassLoader());
+	}
 }

src/main/java/com/googlecode/jsonrpc4j/spring/AutoJsonRpcServiceExporter.java

@@ -44,7 +44,6 @@ public class AutoJsonRpcServiceExporter implements BeanFactoryPostProcessor {
 
 	private ObjectMapper objectMapper;
 	private ErrorResolver errorResolver = null;
-	private Boolean registerTraceInterceptor;
 	private boolean backwardsCompatible = true;
 	private boolean rethrowExceptions = false;
 	private boolean allowExtraParams = false;
@@ -141,10 +140,6 @@ private void registerServiceProxy(DefaultListableBeanFactory defaultListableBean
 			builder.addPropertyValue("invocationListener", invocationListener);
 		}
 
-		if (registerTraceInterceptor != null) {
-			builder.addPropertyValue("registerTraceInterceptor", registerTraceInterceptor);
-		}
-
 		if (httpStatusCodeProvider != null) {
 			builder.addPropertyValue("httpStatusCodeProvider", httpStatusCodeProvider);
 		}
@@ -225,12 +220,16 @@ public void setAllowLessParams(boolean allowLessParams) {
 	}
 
 	/**
-	 * See {@link org.springframework.remoting.support.RemoteExporter#setRegisterTraceInterceptor(boolean)}
+	 * See {@code org.springframework.remoting.support.RemoteExporter#setRegisterTraceInterceptor(boolean)}
+	 * <p>
+	 * Note: this method is deprecated and marked for removal.
+	 * {@code RemoteExporter} and {@code TraceInterceptor-s} are no longer supported.
 	 *
 	 * @param registerTraceInterceptor the registerTraceInterceptor value to set
 	 */
+	@Deprecated
 	public void setRegisterTraceInterceptor(boolean registerTraceInterceptor) {
-		this.registerTraceInterceptor = registerTraceInterceptor;
+		// NOOP
 	}
 
 	/**

src/main/java/com/googlecode/jsonrpc4j/spring/AutoJsonRpcServiceImplExporter.java

@@ -50,7 +50,6 @@ public class AutoJsonRpcServiceImplExporter implements BeanFactoryPostProcessor
 
 	private ObjectMapper objectMapper;
 	private ErrorResolver errorResolver = null;
-	private Boolean registerTraceInterceptor;
 	private boolean backwardsCompatible = true;
 	private boolean rethrowExceptions = false;
 	private boolean allowExtraParams = false;
@@ -181,11 +180,7 @@ private void registerServiceProxy(DefaultListableBeanFactory defaultListableBean
 		if (invocationListener != null) {
 			builder.addPropertyValue("invocationListener", invocationListener);
 		}
-		
-		if (registerTraceInterceptor != null) {
-			builder.addPropertyValue("registerTraceInterceptor", registerTraceInterceptor);
-		}
-		
+
 		if (httpStatusCodeProvider != null) {
 			builder.addPropertyValue("httpStatusCodeProvider", httpStatusCodeProvider);
 		}
@@ -280,14 +275,18 @@ public void setAllowExtraParams(boolean allowExtraParams) {
 	public void setAllowLessParams(boolean allowLessParams) {
 		this.allowLessParams = allowLessParams;
 	}
-	
+
 	/**
-	 * See {@link org.springframework.remoting.support.RemoteExporter#setRegisterTraceInterceptor(boolean)}
+	 * See {@code org.springframework.remoting.support.RemoteExporter#setRegisterTraceInterceptor(boolean)}
+	 * <p>
+	 * Note: this method is deprecated and marked for removal.
+	 * {@code RemoteExporter} and {@code TraceInterceptor-s} are no longer supported.
 	 *
 	 * @param registerTraceInterceptor the registerTraceInterceptor value to set
 	 */
+	@Deprecated
 	public void setRegisterTraceInterceptor(boolean registerTraceInterceptor) {
-		this.registerTraceInterceptor = registerTraceInterceptor;
+		// NOOP
 	}
 
 	/**

src/main/java/com/googlecode/jsonrpc4j/spring/JsonServiceExporter.java

@@ -9,10 +9,7 @@
 import java.io.IOException;
 
 /**
- * {@link HttpRequestHandler} that exports services using Json
- * according to the JSON-RPC proposal specified at:
- * <a href="http://groups.google.com/group/json-rpc">
- * http://groups.google.com/group/json-rpc</a>.
+ * {@link HttpRequestHandler} that exports user services using JSON-RPC over HTTP protocol
  */
 public class JsonServiceExporter extends AbstractJsonServiceExporter implements HttpRequestHandler {
 

src/main/java/com/googlecode/jsonrpc4j/spring/JsonStreamServiceExporter.java

@@ -11,11 +11,7 @@
 
 
 /**
- * {@link org.springframework.remoting.support.RemoteExporter RemoteExporter}
- * that exports services using Json according to the JSON-RPC proposal specified
- * at:
- * <a href="http://groups.google.com/group/json-rpc">
- * http://groups.google.com/group/json-rpc</a>.
+ * Exports user defined services as streaming server, which provides JSON-RPC over sockets.
  */
 @SuppressWarnings("unused")
 public class JsonStreamServiceExporter extends AbstractJsonServiceExporter implements DisposableBean {

src/test/java/com/googlecode/jsonrpc4j/spring/JsonServiceExporterIntegrationTest.java

@@ -0,0 +1,53 @@
+package com.googlecode.jsonrpc4j.spring;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+import com.googlecode.jsonrpc4j.spring.service.Service;
+import com.googlecode.jsonrpc4j.spring.service.ServiceImpl;
+
+import static org.junit.Assert.*;
+
+/**
+ * This test ensures that {@link com.googlecode.jsonrpc4j.spring.JsonServiceExporter} bean is
+ * constructed according to Spring Framework configuration.
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration("classpath:serverApplicationContextC.xml")
+public class JsonServiceExporterIntegrationTest {
+
+	private static final String BEAN_NAME_AND_URL_PATH = "/UserService.json";
+
+	@Autowired
+	private ApplicationContext applicationContext;
+
+	@Test
+	public void testExportedService() {
+		assertNotNull(applicationContext);
+
+		// check that the bean was only exported on the configured path.
+		{
+			Object bean = applicationContext.getBean(BEAN_NAME_AND_URL_PATH);
+			assertEquals(JsonServiceExporter.class, bean.getClass());
+
+			String[] names = applicationContext.getBeanNamesForType(JsonServiceExporter.class);
+			assertNotNull(names);
+			assertEquals(1, names.length);
+			assertEquals(BEAN_NAME_AND_URL_PATH, names[0]);
+		}
+
+		// check that service classes were also successfully configured in the context.
+
+		{
+			Service service = applicationContext.getBean(Service.class);
+			assertTrue(service instanceof ServiceImpl);
+
+			ServiceImpl serviceImpl = applicationContext.getBean(ServiceImpl.class);
+			assertNotNull(serviceImpl);
+		}
+	}
+}

src/test/resources/serverApplicationContextC.xml

@@ -0,0 +1,14 @@
+<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns="http://www.springframework.org/schema/beans"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
+
+    <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/>
+
+    <bean id="userService" class="com.googlecode.jsonrpc4j.spring.service.ServiceImpl">
+    </bean>
+
+    <bean name="/UserService.json" class="com.googlecode.jsonrpc4j.spring.JsonServiceExporter">
+        <property name="service" ref="userService"/>
+        <property name="serviceInterface" value="com.googlecode.jsonrpc4j.spring.service.Service"/>
+    </bean>
+</beans>