Currently, most web services are XML-based due to the advantage of XML self-describing and well support. However, the bandwidth and performance may be the issues for XML based web service.
Binary Web Service, by design, attempts to solve the above issues.
Hessian (
http://hessian.caucho.com/) is one of binary web service implementation. We used it and it is proved to be a good approach. Following is the simple code of showing how to use Hessian.
First we create interface with two methods, hello and hiClient
public interface Basic {
public String hello();
public MyOutputResponse hiClient(MyInputRequest input);
}
Server Side:
1. Create implementation of that interface.
public class BasicService implements Basic {
private String _greeting = "My Hello world";
public void setGreeting(String greeting) {
_greeting = greeting;
}
public String hello() {
return _greeting;
}
public MyOutputResponse hiClient(MyInputRequest input) {
System.out.println(" from client: " + input.toString());
MyOutputResponse response = new MyOutputResponse();
response.setMsg("HI there from " + input.getFirstName());
return response;
}
}
2. Standard web.xml for Hessian service
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<servlet>
<servlet-name>hello</servlet-name>
<servlet-class>com.caucho.hessian.server.HessianServlet</servlet-class>
<init-param>
<param-name>home-class</param-name>
<param-value>example.service.BasicService</param-value>
</init-param>
<init-param>
<param-name>home-api</param-name>
<param-value>example.interfaces.Basic</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>hello</servlet-name>
<url-pattern>/hello</url-pattern>
</servlet-mapping>
</web-app>
Where home-api refers defined interface and home-class is implementation of the interfaces.
Client Side:
public class BasicClient {
public static void main(String []args)
throws Exception
{
String url = "http://localhost/hessian_webapp/hello";
HessianProxyFactory factory = new HessianProxyFactory();
Basic basic = (Basic) factory.create(Basic.class, url);
//test first API hello
System.out.println("Hello from server: " + basic.hello());
//test second API hiClient
MyInputRequest input = new MyInputRequest();
input.setFirstName("Michael");
input.setLastName("W");
MyOutputResponse response = basic.hiClient(input);
System.out.println("hiClient from server: " + response.toString());
}
}
The url of http://localhost/hessian_webapp/hello is the servlet for the service.
HessianProxyFactory factory = new HessianProxyFactory();
Basic basic = (Basic) factory.create(Basic.class, url);
Get reference of the interface
Build/Deploy
I used maven to build Hessian web service and deployed to jboss.
Here is pom file:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>example</groupId>
<artifactId>hessian_webapp</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>hessian_webapp Maven Webapp</name>
<url>http://maven.apache.org</url>
<build>
<finalName>hessian_webapp</finalName>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.5</source>
<target>1.5</target>
</configuration>
</plugin>
</plugins>
</build>
<profiles>
<profile>
<id>client</id>
<build>
<defaultGoal>test</defaultGoal>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<executions>
<execution>
<phase>test</phase>
<goals>
<goal>java</goal>
</goals>
<configuration>
<mainClass>example.client.BasicClient</mainClass>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
</profiles>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.caucho</groupId>
<artifactId>hessian</artifactId>
<version>3.1.5</version>
</dependency>
</dependencies>
</project>
Build/Deploy
1. build: mvn clean package
2. deploy: copy target\hessian_webapp.war to your web server
3. start server.
4. test service with following URL: http://localhost/hessian_webapp/hello
You will get "Hessian Requires POST"
5. Run client BasicClient
In command line:
mvn -Pclient
In Eclipse:
Right click BasicClient, and Run As Java Application.
Source code:
click here to download source code.
