android socket 客戶端實例

   整個流程爲：點擊連接按鈕後，客戶端請求與服務器連接，同時開啓接受數據的新線程。成功後可在文本框裏輸入發送的內容，點擊發送則發送，同時程序可以不斷地接收服務器信息。

下面在講述幾點比較坑的點：
1、切忌，一定要在一個新線程中編寫socket，或者添加以下代碼

//*******解決主線程訪問網絡的問題
        StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
                .detectDiskReads()
                .detectDiskWrites()
                .detectNetwork() // or .detectAll() for all detectable problems
                .penaltyLog()
                .build());
        StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
                .detectLeakedSqlLiteObjects()
                .detectLeakedClosableObjects()
                .penaltyLog()
                .penaltyDeath()
                .build());
//        ************

2、在配置文件中添加以下代碼

  <uses-permission android:name= "android.permission.INTERNET"/>

3、使用如下代碼傳輸數據時

BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()));

每次發送完數據，一定要調用flush()和close()方法。不然會一直接收不到數據

下面附上完整的代碼

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.StrictMode;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.Socket;
import java.net.UnknownHostException;



/**
 * Created by liyongqi on 2016/8/7.
 */
public class Client extends Activity
{
    private EditText mEditText = null;
    private Button connectButton = null;
    private Button sendButton = null;
//    private TextView mTextView = null;
    private Socket clientSocket = null;
    private OutputStream outStream = null;
    private Handler mHandler = null;
    private ReceiveThread mReceiveThread = null;
    private boolean stop = true;
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mian);
        //*******解決主線程訪問網絡的問題
        StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
                .detectDiskReads()
                .detectDiskWrites()
                .detectNetwork() // or .detectAll() for all detectable problems
                .penaltyLog()
                .build());
        StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
                .detectLeakedSqlLiteObjects()
                .detectLeakedClosableObjects()
                .penaltyLog()
                .penaltyDeath()
                .build());
//        ************
        mEditText = (EditText) this.findViewById(R.id.edittext);
//        mTextView = (TextView) this.findViewById(R.id.retextview);
        connectButton = (Button) this.findViewById(R.id.connectbutton);
        sendButton = (Button) this.findViewById(R.id.sendbutton);
        sendButton.setEnabled(false);
        // 連接按鈕監聽
        connectButton.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v) {
                try
                {
                    // 實例化對象並連接到服務器
                    clientSocket = new Socket("192.168.1.157",8889);
                } catch (UnknownHostException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                Log.d("Client","連接成功");
                // 連接按鈕使能
                connectButton.setEnabled(false);
                // 發送按鈕使能
                sendButton.setEnabled(true);
                mReceiveThread = new ReceiveThread(clientSocket);
                stop = false;
                // 開啓線程
                mReceiveThread.start();
            }
        });
        //發送數據按鈕監聽
        sendButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                BufferedWriter bufferedWriter=null;
                try {
                    bufferedWriter = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()));
                } catch (IOException e) {
                    Log.d("Client","BufferedWriter出錯");
                    e.printStackTrace();
                }
                // 獲得EditTex的內容
                String text = mEditText.getText().toString();
                Log.d("Client","即將發送的信息爲："+text);
                try {
                    // 發送數據
                   bufferedWriter.write(text);
                    bufferedWriter.flush();
                    bufferedWriter.close();
                } catch (IOException e) {
                    Log.d("Client","發送數據出錯");
                    e.printStackTrace();
                }
                Log.d("Client","成功發送數據");
                // 清空內容
                mEditText.setText("");

            }
        });
    }

    private class ReceiveThread extends Thread
    {

        private  BufferedReader in = null;
        private String str = null;
        ReceiveThread(Socket s) {
            try {
                // 獲得輸入流
                in = new BufferedReader(new InputStreamReader(s.getInputStream()));
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        @Override
        public void run() {
            while (!stop) {
                // 讀取輸入的數據(阻塞讀)
                try {
                    String s=in.readLine();
                    Log.d("Client",s);
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        }
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        if (mReceiveThread != null) {
            stop = true;
            mReceiveThread.interrupt();
        }
    }
}