Java和c#使用hessian通信
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：http://hessian.caucho.com/ Hssiancharp.dll 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：
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。