java和c#使用hessian通信的方法

本文实例讲述了java和c#使用hessian通信的方法，是非常实用的技巧。分享给大家供大家参考。具体分析如下：

首先，hessian主页为：http://hessian.caucho.com/

下面通过一个简单的例子学习hessian服务：服务端为Java，客户端为C#。

先要准备好C#和Java的第三方类库，下载地址：http://hessian.caucho.com/

下载 Hssiancharp.dll及hessian-4.0.37.jar

Hessian服务端（java）：

打开eclipse创建一个Dynamic Web Project，将hessian-4.0.37.jar放到lib下，大概如图所示：

创建一个通信接口IHello：

package hessian.test.server;
import java.util.ArrayList;
public interface IHello {
  String sayHello(String msg);
  void sayHello2(int bean);
  void print(String msg);
  HelloBean getData(HelloBean bean);
  ArrayList<HelloBean> getBeanList();
  ComplexData getComplexData();

}

IHello接口的一个实现：HelloImpl.java

package hessian.test.server;
import java.util.ArrayList;
public class HelloImpl implements IHello{
  public String sayHello(String msg){
    return "Hello " + msg;
  }
  public void sayHello2(int bean){
    System.out.println("Hello " + bean);
  }
  public void print(String msg){
    System.out.println(msg);
  }
  public HelloBean getData(HelloBean bean){
    HelloBean result = new HelloBean();
    result.setName("lu xiaoxun a new name");
    result.setAge(26);
    System.out.print(bean.getName());
    return result;
  }
  public ArrayList<HelloBean> getBeanList(){
    ArrayList<HelloBean> beans = new ArrayList<HelloBean>();

    HelloBean b1 = new HelloBean();
    b1.setName("lu1");
    b1.setAge(26);
    beans.add(b1);

    HelloBean b2 = new HelloBean();
    b2.setName("lu2");
    b2.setAge(27);
    beans.add(b2);

    return beans;
  }
  public ComplexData getComplexData(){
    ComplexData data = new ComplexData();
    ArrayList<HelloBean> beans = getBeanList();
    data.setData(beans, beans.size());
    return data;
  }
}

定义用来进行数据传输的类，两个类都必须实现Serializable接口：

HelloBean.java

package hessian.test.server;
import java.io.Serializable;
public class HelloBean implements Serializable {
  private static final long serialVersionUID = 570423789882653763L;
  private String name;
  private int age;
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
  public int getAge(){
    return age;
  }
  public void setAge(int age){
    this.age = age;
  }
}

ComplexData.java

package hessian.test.server;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

public class ComplexData implements Serializable{
  private static final long serialVersionUID = 1L;
  private ArrayList<HelloBean> helloBeans;
  //private Map<String, HelloBean> helloBeanMap;
  private int number;
  public int getNumber(){
    return number;
  }
  public ArrayList<HelloBean> getHelloBeans(){
    return helloBeans;
  }
  public void setData(ArrayList<HelloBean> beans, int num){
    this.number = num;
    this.helloBeans = beans;
//    helloBeanMap = new HashMap<String, HelloBean>();
//    for (HelloBean helloBean : beans) {
//      if(!helloBeanMap.containsKey(helloBean.getName()))
//      {
//        helloBeanMap.put(helloBean.getName(), helloBean);
//      }
//    }
  }
}

web.xml内容：

<?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_3_0.xsd"
  id="WebApp_ID" version="3.0">
  <display-name>hessian server</display-name>
  <servlet>
    <servlet-name>hessian</servlet-name>
    <servlet-class>com.caucho.hessian.server.HessianServlet</servlet-class>
    <init-param>
      <param-name>service-class</param-name>
      <param-value>hessian.test.server.HelloImpl</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>hessian</servlet-name>
    <url-pattern>/hessian</url-pattern>
  </servlet-mapping>
</web-app>

Hessian客户端（c#）：

定义一个与服务端对应的IHello接口：IHello.cs

  public interface IHello
  {
    String sayHello(String msg);
    void sayHello2(int bean);
    void print(String msg);
    HelloBean getData(HelloBean bean);
    HelloBean[] getBeanList();
    ComplexData getComplexData();
  }

定义与服务器端一致的的通信数据类：

HelloBean.cs：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace hessian.test.server
{
  public class HelloBean
  {
    public String Name
    {
      set { name = value; }
      get { return name; }
    }

    private String name; //类型和名称需要和服务器端一致

    public int Age
    {
      set { age = value; }
      get { return age; }
    }

    private int age; //类型和名称需要和服务器端一致

    public override String ToString()
    {
      return "Name: "+ name + " Age: " + age;
    }

  }
}

ComplexData.cs：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace hessian.test.server
{
  public class ComplexData
  {
    private HelloBean[] helloBeans;

    //private Dictionary<String, HelloBean> helloBeanMap;

    private int number;

    public int GetNumber()
    {
      return number;
    }

    public HelloBean[] GetBeans()
    {
      return helloBeans;
    }

    //public Dictionary<String, HelloBean> GetBeansDic()
    //{
    //  return helloBeanMap;
    //}
  }
}

在主项目中添加Hessiancsharp.dll引用。

测试代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using hessiancsharp.client;
using hessian.test.server;

namespace HessianClientTest
{
  class Program
  {
    static void Main(string[] args)
    {
      string url = @"http://localhost:8080/HessianServerTest/hessian";
      CHessianProxyFactory factory = new CHessianProxyFactory();

      IHello test = (IHello)factory.Create(typeof(IHello), url);

      //Test function
      Console.WriteLine(test.sayHello("lu"));  //打印从服务器端获取的字符串
      test.sayHello2(12);            //在服务器端控制台打印 "Hello 12"
      test.print("hessian");          //在服务器端控制台打印 "hessian" 

      //Test Object
      HelloBean bean = new HelloBean();
      //bean.setName("lu xiaoxun");
      bean.Name = "luxiaoxun";
      HelloBean result = test.getData(bean);
      Console.WriteLine(result.Name);
      Console.WriteLine(result.Age);
      Console.WriteLine(result);

      //Test Object Array
      HelloBean[] beans = test.getBeanList();
      if (beans != null)
      {
        foreach (HelloBean data in beans)
        {
          Console.WriteLine(data.ToString());
        }
      }

      //Test complex data
      ComplexData complexData = test.getComplexData();
      if (complexData != null)
      {
        Console.WriteLine("Array number: " + complexData.GetNumber());

        HelloBean[] comArray = complexData.GetBeans();
        if (comArray != null)
        {
          foreach (HelloBean data in comArray)
          {
            Console.WriteLine(data.ToString());
          }
        }

        //Dictionary<String, HelloBean> helloBeanMap = complexData.GetBeansDic();
        //if (helloBeanMap != null)
        //{
        //  foreach (String key in helloBeanMap.Keys)
        //  {
        //    Console.WriteLine(helloBeanMap[key].GetHelloBeanInfo());
        //  }
        //}
      }

      Console.ReadKey();
    }
  }
}

测试结果如下图所示：

注意事项：

1、服务端和客户端用于数据传递的对象的命名空间要一致

IHello接口所在命名空间服务端和客户端可以不一致，但是IHello中用到的HelloBean和ComplexData在Java服务端和C#客户端中两个HelloBean类所在的命名空间要一致。

2、类的字段要一致

用于数据传输的类的字段名和字段类型要一致（修饰类型可以不一致）。

3、服务端的类要序列化

4、尽量使用基本的数据类型
从上面的测试可以看出，传递基本的类型没有问题，传递普通的类对象没有问题，传递ArrayList的时候也没有问题（C#客户端使用Array数组），但是传递HashMap字典的时候会有问题，C#这边使用Dictionary没法对应一致，可能是由于hash函数内部实现不一致导致的，具体原因不明。

感兴趣的朋友可以测试一下本文实例，源码点击此处本站下载。