HttpClient

在Android開發中，不可避免的會用到網絡連接，而網絡連接是用到Http協議來發送和接受數據，Android中有用到了兩種方式來進行Http通信，HttpURLConnection和HttpClient，HttpURLConnection在上一篇中已經給出，這裏再給出HttpClient的通信方式。
HttpClient中有兩種方法，DoGet和DoPost方法。

package com.example.administrator.networkdemo;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

/**
 * Created by Administrator on 2015/9/13.
 */
public class HttpClientActivity extends Activity implements View.OnClickListener {
    private Button mButtonDoget;
    private Button mButtonDopost;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_httpclient);
        mButtonDoget = (Button) findViewById(R.id.httpclient_doget);
        mButtonDoget.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.httpclient_doget:
                MyDoGetAsyncTask task = new MyDoGetAsyncTask();
                task.execute();
                break;
            case R.id.httpclient_dopost:
                MyDoPstAsyncTask task2 = new MyDoPstAsyncTask();
                task2.execute();
        }
    }
    class MyDoGetAsyncTask extends AsyncTask<String,String,String>{
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
        }

        @Override
        protected void onProgressUpdate(String... values) {
            super.onProgressUpdate(values);
        }

        @Override
        protected String doInBackground(String... strings) {
            HttpClient client = new DefaultHttpClient();
            String urlString = "http://192.168.0.198:8080/MyAndroidServlet/MyServlet?username=kangsang";
            HttpGet get = new HttpGet(urlString);
            get.setHeader("Content-type","application/x-www-form-urlencoded;charset=UTF-8");
            try {
                HttpResponse response = client.execute(get);
                StatusLine statusLine = response.getStatusLine();
                int code = statusLine.getStatusCode();
                if (code == HttpURLConnection.HTTP_OK){
                    HttpEntity entity = response.getEntity();
                    InputStream is = entity.getContent();
                    BufferedReader br = new BufferedReader(new InputStreamReader(is));
                    String line = br.readLine();
                    while (line!=null){
                        Log.d("",""+line);
                        line = br.readLine();
                    }
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            return "返回結果";
        }
    }
    class MyDoPstAsyncTask extends AsyncTask<String,String,String>{
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
        }

        @Override
        protected void onProgressUpdate(String... values) {
            super.onProgressUpdate(values);
        }

        @Override
        protected String doInBackground(String... strings) {
            String urlString = "http://192.168.0.198:8080/MyAndroidServlet/MyServlet?username=zhangsan";
            try {
                URL url = new URL(urlString);
                URLConnection connect = url.openConnection();
                HttpURLConnection httpConnection = (HttpURLConnection)connect;
                httpConnection.setRequestMethod("POST");
                //設置連接超時時間
                httpConnection.setConnectTimeout(30000);
                //讀取超時時間
                httpConnection.setReadTimeout(30000);
                //設置編碼格式
                // 設置接受的數據類型
                httpConnection.setRequestProperty("Accept-Charset", "utf-8");
                // 設置可以接受序列化的java對象
                httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                //設置請求方法
                httpConnection.setRequestMethod("POST");
                //設置客戶端可以給服務器提交數據，默認是false的。post方法必須設置爲true

                httpConnection.setDoInput(true);
                httpConnection.setDoOutput(true);
                //post方法不允許使用緩存
                httpConnection.setUseCaches(false);
                String params = "username=zhangsan&password=lisi";
                httpConnection.getOutputStream().write(params.getBytes());
                int code = httpConnection.getResponseCode();
                System.out.println("狀態碼"+code);
                if(code == HttpURLConnection.HTTP_OK){
                    InputStream is =  httpConnection.getInputStream();
                    BufferedReader br = new BufferedReader(new InputStreamReader(is));
                    String line = br.readLine();
                    while(line!=null){
                        System.out.println(line);
                        line = br.readLine();
                    }
                }

            } catch (MalformedURLException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
            return null;
        }
    }
}