1 package com.ch.day8_asynctaskdemo;

 2

 3 import java.util.ArrayList;

 4

 5 import com.ch.myutils.NetWorkUtil;

 6

 7 import android.os.AsyncTask;

 8 import android.os.Bundle;

 9 import android.app.Activity;

10 import android.content.Context;

11 import android.util.Log;

12 import android.view.Menu;

13 import android.view.View;

14 import android.view.View.OnClickListener;

15 import android.widget.Button;

16 import android.widget.EditText;

17

18 public class MainActivity extends Activity {

19     private EditText name;

20     private EditText pass;

21     private Button login;

22     Context mcontext;

23

24     @Override

25     protected void onCreate(Bundle savedInstanceState) {

26         super.onCreate(savedInstanceState);

27         setContentView(R.layout.activity_main);

28         mcontext = this;

29         init();

30     }

31

32     public void init(){

33         name = (EditText) findViewById(R.id.username);

34         pass = (EditText) findViewById(R.id.userpass);

35         login = (Button) findViewById(R.id.login);

36

37         login.setOnClickListener(new OnClickListener() {

38             @Override

39             public void onClick(View v) {

40                 String nameV = name.getText().toString();

41                 String passV = pass.getText().toString();

42

43                 //判断网路是否畅通加权限

44                 if(NetWorkUtil.isNetAvailable(mcontext)){//网络畅通

45                     //通过AsyncTask访问服务器

46

47                     new MyAsyncTask().execute(nameV,passV,NetWorkUtil.LOGIN_URL);//调用MyAsyncTask执行请求

48                 }

49             }

50         });

51     }

52     class MyAsyncTask extends AsyncTask<String, Integer, String>{

53         // 后台执行，比较耗时的操作都可以放在这里

54         @Override

55         protected String doInBackground(String... params) {//params的类型和AsyncTask类的第一个泛型对应

56             // TODO Auto-generated method stub

57             String uname = params[0];//得到用户名

58             String upass = params[1];//得到密码

59             String url = params[2];//得到url

60             String rs = NetWorkUtil.loginCheck_Get_HttpClient(uname, upass, url);//请求服务器。得到结果

61

62             return rs;//把请求的结果传递到onPostExecute方法中

63         }

64         //相当于Handler 处理UI的方式，在这里面可以使用在doInBackground 得到的结果处理操作UI

65         @Override

66         protected void onPostExecute(String result) {//result的类型和AsyncTask类的第三个泛型对应

67             // TODO Auto-generated method stub

68             login.setText(result);

69             //判断登陆的结果，决定是否跳转

70

71 //            super.onPostExecute(result);

72         }

73

74     }

75

76

77 }

package com.ch.myutils;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.util.ArrayList;

import java.util.List;

import org.apache.http.HttpEntity;

import org.apache.http.HttpResponse;

import org.apache.http.NameValuePair;

import org.apache.http.client.ClientProtocolException;

import org.apache.http.client.HttpClient;

import org.apache.http.client.entity.UrlEncodedFormEntity;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.impl.client.DefaultHttpClient;

import org.apache.http.message.BasicNameValuePair;

import org.apache.http.params.BasicHttpParams;

import org.apache.http.params.HttpConnectionParams;

import org.apache.http.params.HttpParams;

import org.apache.http.util.EntityUtils;

import android.content.Context;

import android.net.ConnectivityManager;

import android.net.NetworkInfo;

public class NetWorkUtil {

    public static final String LOGIN_URL = "http://169.254.109.73:8080/serverof1407a/loginServlet";

    public static boolean isNetAvailable(Context context){

        //获得网络管理器

        ConnectivityManager connM =

                (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo netInfo = connM.getActiveNetworkInfo();//得到网络详情

        if(netInfo == null || !netInfo.isAvailable())

            return false;

        return true;

    }

    public static String loginCheck_Get_HttpClient(String name,String pass,String url){

        //通过StringBuffer来加工url

        StringBuffer sb = new StringBuffer(url);

        sb.append("?username=");

        sb.append(name);

        sb.append("&userpass=");

        sb.append(pass);

        String result = "";

        HttpGet get = new HttpGet(sb.toString());//创建httpClient的get请求对象

        //设置请求参数

        HttpParams params = new BasicHttpParams();

        HttpConnectionParams.setConnectionTimeout(params, 5*1000);

        HttpConnectionParams.setSoTimeout(params, 5*1000);

        HttpClient client = new DefaultHttpClient(params);//创建HttpClient对象

        try {

            HttpResponse res = client.execute(get);//执行请求，获得结果

            if(res.getStatusLine().getStatusCode() == 200){

                HttpEntity entity = res.getEntity();//获得相应结果，是一个HttpEntity对象

                result = EntityUtils.toString(entity, "utf-8");//转换为字符串

            }

        } catch (ClientProtocolException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return result;

    }

}