handler的使用、服务端客户端交互、Json、Gson
附件有完整代码
package com.example.knowledgedemo;import org.json.JSONException;import org.json.JSONObject;import android.app.Activity;import android.app.ProgressDialog;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.View;import android.widget.Button;import android.widget.EditText;import com.example.entity.loginPerson;import com.example.utils.HttpUtil;import com.example.utils.ToastUtil;import com.google.gson.Gson;/** * 知识点：handler的使用、服务端客户端交互、Json、Gson、 * @author somebody * */public class LoginDemo extends Activity {private EditText loginname, password;private Button login;private ProgressDialog progressdialog;private String name, pwd;@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.login);loginname = (EditText) findViewById(R.id.loginname);password = (EditText) findViewById(R.id.password);login = (Button) findViewById(R.id.login);login.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {login();//点击登录按钮}});}private void login() {showProgressDialog();//显示进度框new Thread() {public void run() {requestServer();//请求服务器}}.start();}private void showProgressDialog() {if (progressdialog == null) {progressdialog = new ProgressDialog(this);}if (progressdialog.isShowing()) {progressdialog.dismiss();}progressdialog.setTitle("提示");progressdialog.setMessage("正在登陆..");progressdialog.show();}private Handler handler = new Handler() {public void handleMessage(Message msg) {super.handleMessage(msg);progressdialog.dismiss();switch (msg.what) {case 0:ToastUtil.longToast(getApplicationContext(),R.string.network_ok);//Toast 提示信息、登录成功break;case 1:ToastUtil.longToast(getApplicationContext(),R.string.network_not_ok);//登录失败break;case 2:ToastUtil.longToast(getApplicationContext(),R.string.network_not_ok);//TimeOut 网络连接失败break;default:break;}}};private void requestServer(){name = loginname.getText().toString();pwd = password.getText().toString();//获取用户名密码loginPerson person = new loginPerson();person.setLoginName(name);person.setPassWord(pwd);Gson g = new Gson();/* * Gson将person对象转换为Json格式的字符串 * 此时obj = {"loginName":"1","passWord":"1"} * */String obj = g.toJson(person);String result = HttpUtil.httpPostCodeParams("login",obj);//请求服务端、获取返回值JSONObject resultObject;if(result.startsWith("TimeOut")||result.length()==0){handler.sendEmptyMessage(2);//请求服务端超时}else{try {//如果不超时、返回的数据格式 {"result":"0"}resultObject = new JSONObject(result);result = resultObject.getString("result");} catch (JSONException e) {e.printStackTrace();}if(result.equals("0")){handler.sendEmptyMessage(0);//登录成功}else if(result.equals("1")){handler.sendEmptyMessage(1);//登录失败}}}}package com.example.entity;public class LoginPerson {private String loginName;private String passWord;public String getLoginName() {return loginName;}public void setLoginName(String loginName) {this.loginName = loginName;}public String getPassWord() {return passWord;}public void setPassWord(String passWord) {this.passWord = passWord;}}package com.example.utils;import java.io.BufferedReader;import java.io.DataOutputStream;import java.io.IOException;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.SocketTimeoutException;import java.net.URL;public class HttpUtil {/** * 传递命令和参数 * * @param postCode * @param obj * @return */public static String httpPostCodeParams(String postCode, String obj) {StringBuilder sbResponse = new StringBuilder();URL url;try {//请求的url = http://10.33.1.204:8888/KnowledgeManagementServer/Servlet/ 加 postCode//服务端ip、端口、服务端项目名、服务端使用servlet+命令的方式响应请求url = new URL(getUrl(postCode));HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setRequestMethod("POST");conn.setReadTimeout(Constants.connectTimeout);conn.setConnectTimeout(Constants.connectTimeout);conn.setDoOutput(true);conn.setDoInput(true);DataOutputStream outStream = new DataOutputStream(conn.getOutputStream());outStream.writeUTF(obj.toString());outStream.flush();outStream.close();int cah = conn.getResponseCode();if (cah != 200) {return "TimeOut";}BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), "utf-8")); String lines;while ((lines = reader.readLine()) != null) {sbResponse.append(lines);}conn.disconnect();} catch (SocketTimeoutException e) {return "TimeOut";} catch (IOException e) {e.printStackTrace();}return sbResponse.toString();}private static String getUrl(String postCode) {return Constants.server + postCode;}}package com.ck.servlet;import java.io.DataInputStream;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.ck.entity.LoginPerson;import com.google.gson.Gson;import com.google.gson.JsonObject;public class LoginServlet extends HttpServlet{@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {resp.setContentType("text/html");resp.setCharacterEncoding("utf-8");PrintWriter out = resp.getWriter();DataInputStream dis = new DataInputStream(req.getInputStream());String param = dis.readUTF();Gson g = new Gson();LoginPerson person = g.fromJson(param, LoginPerson.class);JsonObject jsonObject = new JsonObject();if(person.getLoginName().equals("1")&&person.getPassWord().equals("1")){jsonObject.addProperty("result", "0");}else{jsonObject.addProperty("result", "1");}//{"result":"0"}out.print(jsonObject.toString());out.flush();out.close();}@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {// TODO Auto-generated method stubdoPost(req, resp);}}