android和javaEE更完美的通信-传递对象

the5fire

发布于 2019-02-28 15:45:55

5400

发布于 2019-02-28 15:45:55

继续完善上一篇中的那个代码片，《android和javaEE通信的代码片》中只是简单的向服务器发送请求，没有获取服务器返回数据的操作。

继续看着新浪SDK中的代码，它是通过json来实现的，其实说json，不过是一种数据格式，就算是服务器端传送过来一样要本地解析成数组（新浪是这么做的），代码实现思路到不复杂，只要把json字符串放到json类中（这个类是json提供的），可直接转换对象，或者数组。

不过考虑到新浪是由android和php服务器端进行通信的，json必然是一个简单的方法。但是对于android和javaEE服务器端通信，用json的话还是需要一些操作来处理的，不如直接在网络中传递java对象来的方便（当然，仅仅是一个小实验，两者的安全性如何还不知晓）。

于是写下这些代码，供以后参考：

需要提示的一点：在网络上传递的类，在两端一定要属于相同的包，最起码所属的的包名应该一样。

HttpClient.java:

import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

public class HttpClient {
	public static Response httpRequest(String url, PostParameter[] postParams,
             String httpMethod) {
		int responseCode = -1;
		Response res = null;

		try {
			HttpURLConnection con = null;
			OutputStream osw = null;
			try {
				con = (HttpURLConnection) new URL(url).openConnection();

				con.setDoInput(true);
				if (null != postParams || "POST".equals(httpMethod)) {
				   con.setRequestMethod("POST");
				   con.setRequestProperty("Content-Type",
				           "application/x-www-form-urlencoded");
				   con.setDoOutput(true);
				   String postParam = "";
				   if (postParams != null) {
				   		postParam = encodeParameters(postParams);
				   }
				   byte[] bytes = postParam.getBytes("UTF-8");

				   con.setRequestProperty("Content-Length",
				           Integer.toString(bytes.length));
				   osw = con.getOutputStream();
				   osw.write(bytes);
				   osw.flush();
				   osw.close();
				} 
				responseCode = con.getResponseCode();

				res = new Response(con);

			} finally {

			}
		} catch (Exception e){
			e.printStackTrace();
		}
		return res;
	}

	private static String encodeParameters(PostParameter[] postParams) {
	    StringBuffer buf = new StringBuffer();
	    for (int j = 0; j < postParams.length; j++) {
	        if (j != 0) {
	            buf.append("&");
	        }
	        try {
	            buf.append(URLEncoder.encode(postParams[j].getName(), "UTF-8"))
	            	.append("=").append(URLEncoder.encode(postParams[j].getValue(), "UTF-8"));
	        } catch (java.io.UnsupportedEncodingException neverHappen) {
	        }
	    }
	    return buf.toString();
	}

	public static void main(String[] args) {
		PostParameter[] postParameters = new PostParameter[1];
		postParameters[0] = new PostParameter("loginName","demo");
		Response res = httpRequest("http://localhost:8090/mlabs/user/checkLoginName.action", postParameters,
	             "POST");
		System.out.println("获得服务器端返回对象：" + res.getObjectList());
	}
}

PostParamenter.java

public class PostParameter implements java.io.Serializable, Comparable {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	@Override
	public int compareTo(Object o) {
		// TODO Auto-generated method stub
		return 0;
	}

	public PostParameter(String name, String value) {
		super();
		this.name = name;
		this.value = value;
	}
public PostParameter(){

}
	private String name;
	private String value;

	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getValue() {
		return value;
	}
	public void setValue(String value) {
		this.value = value;
	}
}

Response.java

public class Response {
	private HttpURLConnection con = null;

	public Response(){	}

	public Response(HttpURLConnection con) {
		this.con = con;
	}

	/**
	 * 获取数据
	 */
	public List getObjectList() {
		InputStream is;
		List stus = null;
		try {
			is = con.getInputStream();
			ObjectInputStream ois = new ObjectInputStream(is);
			stus = (List)ois.readObject();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
		return stus;
	}
}

Student.java

public class Student implements java.io.Serializable, Comparable {
    private static final long serialVersionUID = 1L;

     public int compareTo(Object o) {
         // TODO Auto-generated method stub
         return 0;
     }

    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;
    }

	@Override
	public String toString() {
		return "Student [name=" + name + ", age=" + age + "]";
	}
}

另外在服务器端返回数据的代码片段，我是写在一个Action中的：

System.out.println("loginName:"+loginName);
        HttpServletRequest request = ServletActionContext.getRequest();
        HttpServletResponse response = ServletActionContext.getResponse();
        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/plain");
         Student  student = new Student();
        student.setName("huyang");
        student.setAge(24);
         Student  student1 = new Student();
        student1.setName("the5fire");
        student1.setAge(21);
        List list = new ArrayList(2);
        list.add(student);

        list.add(student1);
         System.out.println(list);
         //TODO 仅仅为了测试
        OutputStream outs = response.getOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(outs);
        oos.writeObject(list);
        return null;

最终结果展示：