android 與servlet json數據交互

android客戶

package com.comingx.xzz;
 
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONObject;
 
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
 
public class Main extends Activity {
 
	private static final String TAG = "Main";
	private EditText nameEdit;
	private EditText phoneEdit;
	private EditText resultEdit;
	private Button sendBtn;
	private ProgressDialog progressDialog;
 
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
 
		nameEdit = (EditText) findViewById(R.id.name);
		phoneEdit = (EditText) findViewById(R.id.phone);
		resultEdit = (EditText) findViewById(R.id.result);
		sendBtn = (Button) findViewById(R.id.sendBtn);
		progressDialog = new ProgressDialog(this);
 
		sendBtn.setOnClickListener(new Button.OnClickListener() {
			@Override
			public void onClick(View v) {
				new AT().execute(nameEdit.getText().toString() , phoneEdit.getText().toString());
			}
		});
	}
	class AT extends AsyncTask{
 
		@Override
		protected void onPreExecute() {
			progressDialog.show();
		}
 
		@Override
		protected String doInBackground(String... params) {
			try {
				//請求數據
				HttpClient hc = new DefaultHttpClient();
				HttpPost hp = new HttpPost(
						"http://192.168.1.102:8080/JSONServlet/JSONServlet");
				//請求json報文
				JSONObject jo = new JSONObject();
				if (params.length > 1) {
					jo.put("name", params[0]);
					jo.put("phone", params[1]);
				} else {
					jo.put("err", "error");
				}
				Log.d(TAG, "params : " + jo.toString());
				hp.setEntity(new StringEntity(jo.toString()));
				HttpResponse hr = hc.execute(hp);
				String result = null;
				//獲取返回json報文
				if(hr.getStatusLine().getStatusCode() == 200){
					result = EntityUtils.toString(hr.getEntity());
					Log.d(TAG, "result : " + result);
				}
				//關閉連接
				if (hc != null) {
					hc.getConnectionManager().shutdown();
				}
				return result;
			} catch (Exception e) {
				e.printStackTrace();
				return null;
			}
		}
 
		@Override
		protected void onPostExecute(String result) {
			resultEdit.setText(result);
			progressDialog.cancel();
		}
	}
}

服務器代碼:

package com.comingx.xzz;
 
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Enumeration;
 
import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
/**
 * Servlet implementation class JSONServlet
 */
public class JSONServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
 
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		String result = "";
		try {
			/* 讀取數據 */
			BufferedReader br = new BufferedReader(
					new InputStreamReader((ServletInputStream) req.getInputStream(), "utf-8"));
			StringBuffer sb =new StringBuffer("");
			String temp;
			while((temp=br.readLine())!=null){
				sb.append(temp);
			}
			br.close();
			result = sb.toString();
			System.out.println("請求報文:" + result);
		} catch (Exception e) {
			result = "{err:\"error\"}";
		} finally {
			/* 返回數據 */
			System.out.println("返回報文:" + result);
			PrintWriter pw = resp.getWriter();
			pw.write(result);
			pw.flush();
			pw.close();
		}
	}
 
}

服務器就只有一個servlet來處理.

代碼很明顯.

android利用的是apache的httpClient來實現網絡連接,將json數據儲存與StringEntity中,在設置httpPost的實體setEntity()。利用HttpClient實現網絡請求，再獲取數據result = EntityUtils.toStirng(hr.getEntity());最後將結果顯示於Edittext上。

服務器代碼也很簡單。

利用BufferReader封轉request獲取的InputStream來讀取請求實體，獲取請求json報文，在將報文結果輸出流中，返回給客戶端。