Spring v3.0.2 Learning Note 16 - Integrate With Hessian

Reference Library

%SPRING%/dist/com.springsource.org.aopalliance-1.0.0.jar%SPRING%/dist/org.springframework.aop-3.0.2.RELEASE.jar

%SPRING%/dist/org.springframework.asm-3.0.4.RELEASE.jar

%SPRING%/dist/org.springframework.beans-3.0.2.RELEASE.jar

%SPRING%/dist/org.springframework.context-3.0.4.RELEASE.jar

%SPRING%/dist/org.springframework.core-3.0.2.RELEASE.jar

%SPRING%/dist/org.springframework.expression-3.0.4.RELEASE.jar

%SPRING%/dist/org.springframework.transaction-3.0.2.RELEASE.jar

%SPRING%/dist/org.springframework.web.servlet-3.0.2.RELEASE

%SPRING%/dist/org.springframework.web-3.0.4.RELEASE.jar

%SPRING_DEP%/org.apache.commons/com.springsource.org.apache.commons.logging/1.1.1/com.springsource.org.apache.commons.logging-1.1.1.jar

%SPRING_DEP%/com.caucho/com.springsource.com.caucho/3.2.1/com.springsource.com.caucho-3.2.1.jar

%SPRING_DEP%/javax.servlet/com.springsource.javax.servlet/2.5.0/com.springsource.javax.servlet-2.5.0.jar

Wiring up the DispatcherServlet for Hessian

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5">

<display-name>springhessian</display-name>

<servlet>

<servlet-name>hessianServices</servlet-name>

<servlet-class>org.springframework.web.servlet.DispatcherServlet
</servlet-class>

<load-on-startup>1</load-on-startup>

</servlet>

<servlet-mapping>

<servlet-name>hessianServices</servlet-name>

<url-pattern>/remote/*
</url-pattern>

</servlet-mapping>

</web-app>

Using Spring's DispatcherServlet principles, as known from Spring Web
MVC usage, you can easily wire up such a servlet exposing your services.

Exposing your beans by using the HessianServiceExporter


<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"

xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:component-scan base-package="com.spring.hessian.test" />

<bean id="acctService" class="com.spring.hessian.test.impl.AccountInfoImpl" />

<bean name="/acctService"

class="org.springframework.remoting.caucho.HessianServiceExporter">

<property name="service" ref="acctService" />

<property name="serviceInterface" value="com.spring.hessian.test.IAccountInfo" />

</bean>

</beans>

Above configuration should be stored in WEB-INF/hessianServices-servlet.xml

Take note the configuration file name must be
hessianServices-servlet.xml.

According to spring manual, the file name is remoting-servlet.xml, I tried it but it could not work.

>>> After several try, found the naming rule is <servlet name defined in web.xml>-servlet.xml.

For example, I defined a servlet named hessianServices, so the configure file will be hessianServices-servlet.xml

Source Code


// interface

package com.spring.hessian.test;

import com.spring.hessian.test.bean.AccountInfo;

public interface IAccountInfo {

public void createAccount(AccountInfo accountInfo);

public boolean changeEmail(int accountId, String newEmail);

public void deleteAccount(int accountId);

}

// implement class

package com.spring.hessian.test.impl;

import org.springframework.stereotype.Service;

import com.spring.hessian.test.IAccountInfo;

import com.spring.hessian.test.bean.AccountInfo;

@Service

public class AccountInfoImpl implements IAccountInfo {

@Override

public boolean changeEmail(int accountId, String newEmail) {

System.out.println("Here is the logic to change email.");

return false;

}

@Override

public void createAccount(AccountInfo accountInfo) {

System.out

.println("Here is the logic to create account with account info = "

+ accountInfo.toString());

}

@Override

public void deleteAccount(int accountId) {

System.out.println("Here is the logic to delete account with ID = "

+ accountId);

}

}

// domain class

package com.spring.hessian.test.bean;

import java.io.Serializable;

public class AccountInfo implements Serializable {

private static final long serialVersionUID = 5308953586718817188L;

private int accountId;

private String userName;

private String password;

private String email;

public AccountInfo() {

super();

}

public AccountInfo(int accountId, String userName, String password,

String email) {

super();

this.accountId = accountId;

this.userName = userName;

this.password = password;

this.email = email;

}

public int getAccountId() {

return accountId;

}

public void setAccountId(int accountId) {

this.accountId = accountId;

}

public String getUserName() {

return userName;

}

public void setUserName(String userName) {

this.userName = userName;

}

public String getPassword() {

return password;

}

public void setPassword(String password) {

this.password = password;

}

public String getEmail() {

return email;

}

public void setEmail(String email) {

this.email = email;

}

public String toString() {

return "AccountInfo:[id]=" + this.accountId + ",[userName]="

+ this.userName + ",[pwd]=" + this.password + ",[email]="

+ this.email;

}

}

// Junit test

package com.spring.hessian.test;

import org.junit.AfterClass;

import org.junit.BeforeClass;

import org.junit.Test;

import com.caucho.hessian.client.HessianProxyFactory;

import com.spring.hessian.test.bean.AccountInfo;

public class HessianTester {

@BeforeClass

public static void setUpBeforeClass() throws Exception {

}

@AfterClass

public static void tearDownAfterClass() throws Exception {

}

@Test

public void test() throws Exception {

String url = "http://localhost:8080/springhessian/remote/acctService";

HessianProxyFactory factory = new HessianProxyFactory();

IAccountInfo accountInfo = (IAccountInfo) factory.create(

IAccountInfo.class, url);

AccountInfo account = new AccountInfo(125, "myName", "myPwd",

"abc@email.com");

accountInfo.createAccount(account);

accountInfo.changeEmail(126, "def@email.com");

accountInfo.deleteAccount(129);

}

}

From tomcat console ,we can see the output if running above junit test case.
Here is the logic to create account with account info = AccountInfo:[id]=125,[userName]=myName,[pwd]=myPwd,[email]=abc@email.com

Here is the logic to change email.

Here is the logic to delete account with ID = 129

未解决的问题

以上代码和配置在tomcat中一切正常，但是移到weblogic v10.3下，当调用第一个远程方法后总会碰到空指针异常

<Oct 29, 2010 1:42:20 PM SGT> <Error> <Kernel> <BEA-000802> <ExecuteRequest failed

java.lang.NullPointerException.

java.lang.NullPointerException

at weblogic.utils.http.HttpChunkInputStream.initChunk(HttpChunkInputStream.java:66)

at weblogic.utils.http.HttpChunkInputStream.skip(HttpChunkInputStream.java:197)

at weblogic.utils.http.HttpChunkInputStream.skipAllChunk(HttpChunkInputStream.java:371)

at weblogic.servlet.internal.ServletInputStreamImpl.ensureChunkedConsumed(ServletInputStreamImpl.java:30)

at weblogic.servlet.internal.ServletRequestImpl.skipUnreadBody(ServletRequestImpl.java:192)

Truncated. see log file for complete stacktrace

>

到现在仍没找到原因，不得已还是采用hessian的配置方式

<servlet>

<servlet-name>HessianServlet</servlet-name>

<servlet-class>com.caucho.hessian.server.HessianServlet</servlet-class>

<init-param>

<param-name>home-class</param-name>

<param-value>com.spring.hessian.test.impl.AccountInfoImpl</param-value>

</init-param>

<init-param>

<param-name>home-api</param-name>

<param-value>com.spring.hessian.test.IAccountInfo</param-value>

</init-param>

</servlet>

<servlet-mapping>

<servlet-name>HessianServlet</servlet-name>

<url-pattern>/remote2</url-pattern>

</servlet-mapping>

客户端改用这个URL "http://<host>:<port>/hessian/remote2" 在weblogic下可得正确结果。

如果采用hessian的配置方式，以下依赖包就不再需要了

%SPRING%/dist/org.springframework.web.servlet-3.0.2.RELEASE

%SPRING%/dist/org.springframework.web-3.0.4.RELEASE.jar

以下配置文件不再需要

WEB-INF/hessianServices-servlet.xml

web.xml内容改为：

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5">

<display-name>springhessian</display-name>

<servlet>

<servlet-name>HessianServlet</servlet-name>

<servlet-class>com.caucho.hessian.server.HessianServlet</servlet-class>

<init-param>

<param-name>home-class</param-name>

<param-value>com.spring.hessian.test.impl.AccountInfoImpl</param-value>

</init-param>

<init-param>

<param-name>home-api</param-name>

<param-value>com.spring.hessian.test.IAccountInfo</param-value>

</init-param>

</servlet>

<servlet-mapping>

<servlet-name>HessianServlet</servlet-name>

<url-pattern>/remote2</url-pattern>

</servlet-mapping>

</web-app>

WEB-INF/classes 需要spring的配置文件，内容为：

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"

xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:component-scan base-package="com.spring.hessian.test" />

</beans>

为了部属到weblogic,还需要配置文件WEB-INF/weblogic.xml， 其内容为：

<?xml version='1.0' encoding='UTF-8'?>

<weblogic-web-app xmlns="http://www.bea.com/ns/weblogic/weblogic-web-app"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://www.bea.com/ns/weblogic/weblogic-web-app http://www.bea.com/ns/weblogic/weblogic-web-app/1.0/weblogic-web-app.xsd">
<!-- share session in clustering env. -->

<session-descriptor>

<persistent-store-type>replicated_if_clustered</persistent-store-type>

<sharing-enabled>true</sharing-enabled>

</session-descriptor>

<!-- load customized library files first -->

<container-descriptor>

<prefer-web-inf-classes>true</prefer-web-inf-classes>

</container-descriptor>

<!-- set root context -->

<context-root>/hessian</context-root>

</weblogic-web-app>