java基於Socket做一個簡單下載器

本文實例為大家分享了java基於Socket製作下載器的過程，及相關代碼，供大家參考，具體內容如下

1.首先要建立一個服務器用來處理信息並給客戶端傳輸文件(電腦)
我是用電腦開了一個WIFI，手機連上後使用scoket傳輸的
SERVERIP要根據自己實際情況更改。端口也可以隨便更改0~65535，盡量選大一點

import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileInputStream;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.net.ServerSocket;import java.net.Socket;/** * 測試Android客戶端與PC服務器通過socket進行交互服務器端：接收客戶端的信息並回送給客戶* * @author Ameyume * */public class Server implements Runnable { //定義傳輸的IP和端口信息public static final String SERVERIP = "192.168.155.1"; //定義的9888端口public static final int SERVERPORT = 9888; //定義文件private File file = null; public static void main(String[] args) { //建立調用線程執行傳輸的方法Thread desktopServerThread = new Thread(new Server()); desktopServerThread.start(); } public void run() { try { System.out.println("S: Connecting...9888"); //創建套接字ServerSocket serverSocket = new ServerSocket(SERVERPORT); while (true) { // 等待接受客戶端請求Socket client = serverSocket.accept(); System.out.println("S: Receiving...9888"); try { // 接受客戶端信息BufferedReader in = new BufferedReader( new InputStreamReader(client.getInputStream())); System.out.println("S: 接收客戶端信息"); // 讀取客戶端的信息String str = in.readLine(); String str1 = str.substring(0,2); String str2 = str.substring(2); System.out.println(str); //根據客戶端的請求找到對應的文件並把文件大小的值傳過去if (str.equals("file_size")) { //定義你要傳輸的文件（我這裡寫的是E盤下的某個文件） file = new File("E://某個文件"); //輸入流FileInputStream fis = new FileInputStream(file); //輸出流BufferedInputStream bis = new BufferedInputStream(fis); //計算將要傳輸的文件大小int sum = bis.available(); //將int型的文件大小轉成字符串String s = String.valueOf(sum); System.out.println(s); //建立輸出流以發送文件大小的信息PrintWriter out = new PrintWriter(new BufferedWriter( new OutputStreamWriter(client.getOutputStream())), true); //發送文件的大小信息out.println(s); //關閉流out.flush(); bis.close(); } else if (str1.equals("ok")) { int a = Integer.parseInt(str2); // 客戶端收到文件大小的值後，再根據客戶端傳來的“ok”將文件傳過去BufferedOutputStream bos = new BufferedOutputStream( client.getOutputStream()); System.out.println("S: 開始傳輸"); //開始傳輸if (true) { //輸入流FileInputStream fis = new FileInputStream(file); //跳過前面已經傳輸過的字節fis.skip(a); //緩衝輸入流BufferedInputStream bis = new BufferedInputStream( fis); int t = -1; while ((t = bis.read()) >= 0) { bos.write(t); } String s = "已傳輸"; //關閉流bos.flush(); bis.close(); bos.close(); // serverSocket.close(); System.out.println("S: Received: '" + s + "'"); } } else { System.out .println("Not receiver anything from client!"); } } catch (Exception e) { System.out.println("S: Error 1"); e.printStackTrace(); } finally { client.close(); System.out.println("S: Done."); } } } catch (Exception e) { System.out.println("S: Error 2"); e.printStackTrace(); } }}

2.再建立一個客戶端，我這裡用的是安卓寫的MainActivity.java（我是在手機上運行的）

 package com.xhy.zz;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;public class MainActivity extends Activity { // 定義Handler public static Handler myHandler; // 定義intent private Intent intent; // 獲取控件private TextView text_name; private TextView text_percent; private Button btn_start; private Button btn_stop; // 文件顯示private TextView text_sel_file; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); text_name = (TextView) findViewById(R.id.text_name); text_percent = (TextView) findViewById(R.id.text_percent); btn_start = (Button) findViewById(R.id.btn_start); btn_stop = (Button) findViewById(R.id.btn_stop); // 按鈕一的返回信息，顯示進度myHandler = new Handler() { @Override public void handleMessage(Message msg) { super.handleMessage(msg); if (msg.what == 0x0001) { Bundle data = msg.getData(); String str = data.getString("value"); text_percent.setText(str); } } }; // 顯式的方式調用HelloService intent = new Intent(this, DownService.class); // 設置啟動按鈕點擊事件btn_start.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // 開啟服務startService(intent); } }); // 設置停止按鈕點擊事件btn_stop.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // 關閉服務stopService(intent); } }); } /*** * 被調用Activity一旦返回值該回調方法將被系統自動調用*/ @Override protected void onActivityResult(int requestCode, int resultCode, Intent intent) { super.onActivityResult(requestCode, resultCode, intent); // 如果請求碼是0 // 並且返回的結果碼為1 // 請求的Activity可能返回多種結果碼if (requestCode == 0 && resultCode == 1) { // 取出數據Bundle data = intent.getExtras(); String str = data.getString("files"); // 顯示數據text_sel_file.setText(str); } }}

3.activity_main.xml文件

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="20dp" android:orientation="horizontal" > <TextView android:id="@+id/text_name" android:layout_width="160dp" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:text="1" /> <TextView android:id="@+id/text_percent" android:layout_width="50dp" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:layout_marginLeft="20dp" android:text="0%"/> <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="20dp" android:orientation="vertical" > <Button android:id="@+id/btn_start" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="start" /> <Button android:id="@+id/btn_stop" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="stop" /> </LinearLayout> </LinearLayout> </LinearLayout>

4.DownService用於在後台開啟線程執行下載

package com.xhy.zz;import java.io.BufferedInputStream;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileOutputStream;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.net.InetAddress;import java.net.Socket;import java.net.UnknownHostException;import android.app.Service;import android.content.Context;import android.content.Intent;import android.content.SharedPreferences;import android.os.Bundle;import android.os.Environment;import android.os.IBinder;import android.os.Message;import android.util.Log;public class DownService extends Service { private static final String TAG = "Socket_Android"; // Preferece機制操作的文件名public static final String PREFERENCE_NAME = "DownService"; // Preferece機制的操作模式public static int MODE = Context.MODE_PRIVATE; // 線程private Thread workThread; // 定義文件名private String filename="file"; // 端口號private int port = 9888; private boolean isStop = false; /*** * 必須要實現的方法*/ @Override public IBinder onBind(Intent intent) { return null; } @Override public void onCreate() { super.onCreate(); } @Override public int onStartCommand(Intent intent, int flags, int startId) { Log.v("TCP", filename); // 建立傳輸的方法Runnable backgroundWork = new Runnable() { @Override public void run() { // setTitle("測試Socket連接"); Socket socket = null; Socket socket1 = null; try { /* * 指定Server的IP地址，此地址為局域網地址，如果是使用WIFI上網，則為PC機的WIFI IP地址* 在ipconfig查看到的IP地址如下： Ethernet adapter 無線網絡連接: * Connection-specific DNS Suffix . : IP Address. . . . * . . . . . . . . : 192.168.155.1 */ InetAddress serverAddr = InetAddress .getByName("192.168.155.1");// TCPServer.SERVERIP Log.d("TCP", "C: Connecting..."); Log.d("TCP", filename + " " + port); // 應用Server的IP和端口建立Socket對象，向服務端發送請求獲取文件大小的值socket1 = new Socket(serverAddr, port); String message = "---Test_Socket_Android---"; Log.d("TCP", "C: Sending: '" + message + "'"); // 將信息通過這個對象來發送給Server PrintWriter out = new PrintWriter(new BufferedWriter( new OutputStreamWriter( socket1.getOutputStream())), true); // 把用戶輸入的內容髮送給server out.println("file_size"); out.flush(); // 接收服務器信息BufferedReader in = new BufferedReader( new InputStreamReader(socket1.getInputStream())); // 獲取文件大小String str1 = in.readLine(); Log.d("TCP", str1); // 將文件大小轉成int型int sum = Integer.parseInt(str1); Log.d("TCP", str1); // 關閉輸入流in.close(); SharedPreferences sharedPreferences = getSharedPreferences( PREFERENCE_NAME, MODE); SharedPreferences.Editor editor = sharedPreferences .edit(); //取出已經傳輸了的字節int pre = sharedPreferences.getInt("DownService", 0); int _pre = pre; //將其轉化為字符串以便發送給服務端String s = String.valueOf(_pre); // 應用Server的IP和端口建立Socket對象再次向服務端發送請求，以獲取文件內容socket = new Socket(serverAddr, port); // 向服務端發送請求獲得文件的字符PrintWriter out1 = new PrintWriter( new BufferedWriter(new OutputStreamWriter( socket.getOutputStream())), true); out1.println("ok"+s); out1.flush(); out.close(); // 定義輸入流BufferedInputStream bis = new BufferedInputStream( socket.getInputStream()); String file1 = filename; String file; // 判斷手機是否插入了SDCard，是則將文件插入內存卡if (Environment.getExternalStorageState().equals( Environment.MEDIA_MOUNTED)) { File sdCard = Environment .getExternalStorageDirectory(); // SD卡定義文件file = sdCard.getCanonicalFile() + "/" + file1; // 定義文件輸出流FileOutputStream fos = new FileOutputStream(file,true); try { int t = -1; int downloaded = pre; // 定義每次傳輸的字節數byte[] buff = new byte[8192]; Log.i("sum", sum + ""); // 開始將服務端的文件寫入手機SD卡中while ((t = bis.read(buff)) != -1) { if (isStop == true) { break; } fos.write(buff, 0, t); downloaded += t; //將傳輸的進度存儲起來editor.putInt("DownService", downloaded); editor.commit(); //當傳完了則把存儲信息歸零if (downloaded == sum) { editor.putInt("DownService", 0); editor.commit(); } // 獲得文件傳輸的進度float wb = ((downloaded * 100) / (float) sum); int wi = (int) wb; System.out.println(downloaded); String str = String.valueOf(wi) + "%"; // 將文件的傳輸進度給送給BaseActivity,以顯示給用戶Message msg = new Message(); // 生成消息// 生成消息msg.what = 0x0001; // 設置消息類型// 生成Bundle攜帶數據Bundle data = new Bundle(); data.putString("value", str); msg.setData(data); // 利用Handler發送消息MainActivity.myHandler.sendMessage(msg); } // 關閉輸入輸出流bis.close(); fos.flush(); fos.close(); } catch (Exception e) { bis.close(); fos.flush(); fos.close(); } } Log.d(TAG, "From server:'已接收" + "'"); } catch (UnknownHostException e) { Log.e(TAG, "192.168.155.1 is unkown server!"); } catch (Exception e) { e.printStackTrace(); } finally { try { socket.close(); } catch (Exception e) { e.printStackTrace(); } } } }; workThread = new Thread(backgroundWork); // isAlive方法用於判斷workThread線程是否被開啟if (!workThread.isAlive()) { // 生成新線程workThread.start(); Log.v("ServiceLife", "線程開始工作"); } else { Log.v("workThread", "線程已經被調用"); } return START_STICKY; } @Override public void onDestroy() { super.onDestroy(); // 利用interrupt方式中斷該線程isStop = true; Log.v("ServiceLife", "onDestroy方法被調用"); }}

5、最後別忘了註冊AndroidManifest.xml

 <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" > </uses-permission> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" > </uses-permission> <service android:name=".DownService" ></service>

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。