Android中Socket大文件断点上传

什么是Socket?

所谓Socket通常也称作“套接字”，用于描述IP地址和端口，是一个通信连的句柄，应用程序通常通过“套接字”向网络发送请求或者应答网络请求，它就是网络通信过程中端点的抽象表示。它主要包括以下两个协议：

TCP (Transmission Control Protocol 传输控制协议)：传输控制协议,提供的是面向连接、可靠的字节流服务。当客户和服务器彼此交换数据前，必须先在双方之间建立一个TCP连接，之后才能传输 数据。TCP提供超时重发，丢弃重复数据，检验数据，流量控制等功能，保证数据能从一端传到另一端。

UDP (User Datagram Protocl
用户数据报协议)：用户数据报协议，是一个简单的面向数据报的运输层协议。UDP不提供可靠性，它只是把应用程序传给IP层的数据报发送出去，但是并不能
保证它们能到达目的地。由于UDP在传输数据报前不用在客户和服务器之间建立一个连接，且没有超时重发等机制，故而传输速度很快。

详细解说如下:

TCP传输和UDP不一样，TCP传输是流式的，必须先建立连接，然后数据流沿已连接的线路(虚电路)传输。因此TCP的数据流不会像UDP数据报一样，
每个数据报都要包含目标地址和端口，因为每个数据报要单独路由。TCP传输则只需要在建立连接时指定目标地址和端口就可以了。

　　形象的讲，TCP就像打电话，UDP就像发电报。宏观上来看UDP是不分客户端和服务端的。通信双方是平等的。微
观上来讲只相对一个报文，发送端是客户端，监听端是服务端。发送端把数据报发给路由器就像把电报发给了邮局，后面的事情就是发送者无法控制，也无从知晓的
了。所以说是不可靠的，可能会出现报文丢失而无从知晓。就像每张电报都要有收件人一样，每个数据报都要有目的地址和端口。

　　而TCP每次连接都
是分客户端和服务端的。连接的发起者(相当与拨号打电话的人)是客户端，监听者(相当于在电话边等着接电话的人)是服务端。发起者指定要连接的服务器地址
和端口(相当于拨号)，监听者通过和发起者三次握手建立连接(相当于听到电话响去接电话)。建立连接后双方可以互相发送和接受数据(打电话)。

Java如何操作Socket?

值得一提的是，Java分别为TCP和UDP提供了相应的类,TCP是java.net中提供了两个类Socket和ServerSocket，分别用来
表示双向连接的客户端和服务端。这是两个封装得非常好的类，使用起来很方便！UDP是java.net.DatagramSocket.

127.0.0.1是回路地址,用于测试,相当于localhost本机地址,没有网卡,不设DNS都可以访问,端口地址在0~65535之间,其中
0~1023之间的端口是用于一些知名的网络服务和应用,用户的普通网络应用程序应该使用1024以上的端口.

Socket通信模型如下：



如果大家对Java Socket编程还有模糊的地方抓紧温习(/article/1352627.html),本文不在此赘述,下面我们以最常用的TCP协议举例:

服务器，使用ServerSocket监听指定的端口，端口可以随意指定（由于1024以下的端口通常属于保留端口，在一些操作系统中不可以随意使用，所以建议使用大于1024的端口），等待客户连接请求，客户连接后，会话产生；在完成会话后，关闭连接。

客户端，使用Java socket通信对网络上某一个服务器的某一个端口发出连接请求，一旦连接成功，打开会话；会话完成后，关闭Socket。客户端不需要指定打开的端口，通常临时的、动态的分配一个1024以上的端口。

TCP网络连接模型：





Android客户端程序代分析:

[java] view plaincopy

UploadActivity.java

package com.android.upload;

import java.io.File;

import java.io.OutputStream;

import java.io.PushbackInputStream;

import java.io.RandomAccessFile;

import java.net.Socket;

import android.app.Activity;

import android.os.Bundle;

import android.os.Environment;

import android.os.Handler;

import android.os.Message;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.ProgressBar;

import android.widget.TextView;

import android.widget.Toast;

import com.android.service.UploadLogService;

import com.android.socket.utils.StreamTool;

public class UploadActivity extends Activity {

private EditText filenameText;

private TextView resulView;

private ProgressBar uploadbar;

private UploadLogService logService;

private boolean start=true;

private Handler handler = new Handler(){

@Override

public void handleMessage(Message msg) {

int length = msg.getData().getInt("size");

uploadbar.setProgress(length);

float num = (float)uploadbar.getProgress()/(float)uploadbar.getMax();

int result = (int)(num * 100);

resulView.setText(result+ "%");

if(uploadbar.getProgress()==uploadbar.getMax()){

Toast.makeText(UploadActivity.this, R.string.success, 1).show();

}

}

};

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

logService = new UploadLogService(this);

filenameText = (EditText)this.findViewById(R.id.filename);

uploadbar = (ProgressBar) this.findViewById(R.id.uploadbar);

resulView = (TextView)this.findViewById(R.id.result);

Button button =(Button)this.findViewById(R.id.button);

Button button1 =(Button)this.findViewById(R.id.stop);

button1 .setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

start=false;

}

});

button.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

start=true;

String filename = filenameText.getText().toString();

if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){

File uploadFile = new File(Environment.getExternalStorageDirectory(), filename);

if(uploadFile.exists()){

uploadFile(uploadFile);

}else{

Toast.makeText(UploadActivity.this, R.string.filenotexsit, 1).show();

}

}else{

Toast.makeText(UploadActivity.this, R.string.sdcarderror, 1).show();

}

}

});

}

/**

* 上传文件

* @param uploadFile

*/

private void uploadFile(final File uploadFile) {

new Thread(new Runnable() {

@Override

public void run() {

try {

uploadbar.setMax((int)uploadFile.length());

String souceid = logService.getBindId(uploadFile);

String head = "Content-Length="+ uploadFile.length() + ";filename="+ uploadFile.getName() + ";sourceid="+

(souceid==null? "" : souceid)+"\r\n";

Socket socket = new Socket("192.168.1.78",7878);

OutputStream outStream = socket.getOutputStream();

outStream.write(head.getBytes());

PushbackInputStream inStream = new PushbackInputStream(socket.getInputStream());

String response = StreamTool.readLine(inStream);

String[] items = response.split(";");

String responseid = items[0].substring(items[0].indexOf("=")+1);

String position = items[1].substring(items[1].indexOf("=")+1);

if(souceid==null){//代表原来没有上传过此文件，往数据库添加一条绑定记录

logService.save(responseid, uploadFile);

}

RandomAccessFile fileOutStream = new RandomAccessFile(uploadFile, "r");

fileOutStream.seek(Integer.valueOf(position));

byte[] buffer = new byte[1024];

int len = -1;

int length = Integer.valueOf(position);

while(start&&(len = fileOutStream.read(buffer)) != -1){

outStream.write(buffer, 0, len);

length += len;

Message msg = new Message();

msg.getData().putInt("size", length);

handler.sendMessage(msg);

}

fileOutStream.close();

outStream.close();

inStream.close();

socket.close();

if(length==uploadFile.length()) logService.delete(uploadFile);

} catch (Exception e) {

e.printStackTrace();

}

}

}).start();

}

}

StreamTool.java

package com.android.socket.utils;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.PushbackInputStream;

public class StreamTool {

public static void save(File file, byte[] data) throws Exception {

FileOutputStream outStream = new FileOutputStream(file);

outStream.write(data);

outStream.close();

}

public static String readLine(PushbackInputStream in) throws IOException {

char buf[] = new char[128];

int room = buf.length;

int offset = 0;

int c;

loop: while (true) {

switch (c = in.read()) {

case -1:

case '\n':

break loop;

case '\r':

int c2 = in.read();

if ((c2 != '\n') && (c2 != -1)) in.unread(c2);

break loop;

default:

if (--room < 0) {

char[] lineBuffer = buf;

buf = new char[offset + 128];

room = buf.length - offset - 1;

System.arraycopy(lineBuffer, 0, buf, 0, offset);

}

buf[offset++] = (char) c;

break;

}

}

if ((c == -1) && (offset == 0)) return null;

return String.copyValueOf(buf, 0, offset);

}

/**

* 读取流

* @param inStream

* @return 字节数组

* @throws Exception

*/

public static byte[] readStream(InputStream inStream) throws Exception{

ByteArrayOutputStream outSteam = new ByteArrayOutputStream();

byte[] buffer = new byte[1024];

int len = -1;

while( (len=inStream.read(buffer)) != -1){

outSteam.write(buffer, 0, len);

}

outSteam.close();

inStream.close();

return outSteam.toByteArray();

}

}

UploadLogService.java

package com.android.service;

import java.io.File;

import android.content.Context;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

public class UploadLogService {

private DBOpenHelper dbOpenHelper;

public UploadLogService(Context context){

this.dbOpenHelper = new DBOpenHelper(context);

}

public void save(String sourceid, File uploadFile){

SQLiteDatabase db = dbOpenHelper.getWritableDatabase();

db.execSQL("insert into uploadlog(uploadfilepath, sourceid) values(?,?)",

new Object[]{uploadFile.getAbsolutePath(),sourceid});

}

public void delete(File uploadFile){

SQLiteDatabase db = dbOpenHelper.getWritableDatabase();

db.execSQL("delete from uploadlog where uploadfilepath=?", new Object[]{uploadFile.getAbsolutePath()});

}

public String getBindId(File uploadFile){

SQLiteDatabase db = dbOpenHelper.getReadableDatabase();

Cursor cursor = db.rawQuery("select sourceid from uploadlog where uploadfilepath=?",

new String[]{uploadFile.getAbsolutePath()});

if(cursor.moveToFirst()){

return cursor.getString(0);

}

return null;

}

}

DBOpenHelper.java

package com.android.service;

import android.content.Context;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;

public class DBOpenHelper extends SQLiteOpenHelper {

public DBOpenHelper(Context context) {

super(context, "upload.db", null, 1);

}

@Override

public void onCreate(SQLiteDatabase db) {

db.execSQL("CREATE TABLE uploadlog (_id integer primary key autoincrement, uploadfilepath varchar(100), sourceid varchar(10))");

}

@Override

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

db.execSQL("DROP TABLE IF EXISTS uploadlog");

onCreate(db);

}

}

main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

<TextView

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/filename"

/>

<EditText

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="022.jpg"

android:id="@+id/filename"

/>

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="@string/button"

android:id="@+id/button"

/>

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="暂停"

android:id="@+id/stop"

/>

<ProgressBar

android:layout_width="fill_parent"

android:layout_height="20px"

style="?android:attr/progressBarStyleHorizontal"

android:id="@+id/uploadbar"

/>

<TextView

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:gravity="center"

android:id="@+id/result"

/>

</LinearLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.android.upload"

android:versionCode="1"

android:versionName="1.0" >

<uses-sdk android:minSdkVersion="8" />

<application

android:icon="@drawable/ic_launcher"

android:label="@string/app_name" >

<activity

android:name=".UploadActivity"

android:label="@string/app_name" >

<intent-filter>

<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />

</intent-filter>

</activity>

</application>

<!-- 访问网络的权限 -->

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

<!-- 在SDCard中创建与删除文件权限 -->

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

<!-- 往SDCard写入数据权限 -->

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

</manifest>

Java服务端:

[java] view plaincopy

SocketServer.javapackage com.android.socket.server;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.OutputStream;

import java.io.PushbackInputStream;

import java.io.RandomAccessFile;

import java.net.ServerSocket;

import java.net.Socket;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.HashMap;

import java.util.Map;

import java.util.Properties;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import com.android.socket.utils.StreamTool;

public class SocketServer {

private String uploadPath="D:/uploadFile/";

private ExecutorService executorService;// 线程池

private ServerSocket ss = null;

private int port;// 监听端口

private boolean quit;// 是否退出

private Map<Long, FileLog> datas = new HashMap<Long, FileLog>();// 存放断点数据，最好改为数据库存放

public SocketServer(int port) {

this.port = port;

// 初始化线程池

executorService = Executors.newFixedThreadPool(Runtime.getRuntime()

.availableProcessors() * 50);

}

// 启动服务

public void start() throws Exception {

ss = new ServerSocket(port);

while (!quit) {

Socket socket = ss.accept();// 接受客户端的请求

// 为支持多用户并发访问，采用线程池管理每一个用户的连接请求

executorService.execute(new SocketTask(socket));// 启动一个线程来处理请求

}

}

// 退出

public void quit() {

this.quit = true;

try {

ss.close();

} catch (IOException e) {

e.printStackTrace();

}

}

public static void main(String[] args) throws Exception {

SocketServer server = new SocketServer(7878);

server.start();

}

private class SocketTask implements Runnable {

private Socket socket;

public SocketTask(Socket socket) {

this.socket = socket;

}

@Override

public void run() {

try {

System.out.println("accepted connenction from "

+ socket.getInetAddress() + " @ " + socket.getPort());

PushbackInputStream inStream = new PushbackInputStream(

socket.getInputStream());

// 得到客户端发来的第一行协议数据：Content-Length=143253434;filename=xxx.3gp;sourceid=

// 如果用户初次上传文件，sourceid的值为空。

String head = StreamTool.readLine(inStream);

System.out.println(head);

if (head != null) {

// 下面从协议数据中读取各种参数值

String[] items = head.split(";");

String filelength = items[0].substring(items[0].indexOf("=") + 1);

String filename = items[1].substring(items[1].indexOf("=") + 1);

String sourceid = items[2].substring(items[2].indexOf("=") + 1);

Long id = System.currentTimeMillis();

FileLog log = null;

if (null != sourceid && !"".equals(sourceid)) {

id = Long.valueOf(sourceid);

log = find(id);//查找上传的文件是否存在上传记录

}

File file = null;

int position = 0;

if(log==null){//如果上传的文件不存在上传记录,为文件添加跟踪记录

String path = new SimpleDateFormat("yyyy/MM/dd/HH/mm").format(new Date());

File dir = new File(uploadPath+ path);

if(!dir.exists()) dir.mkdirs();

file = new File(dir, filename);

if(file.exists()){//如果上传的文件发生重名，然后进行改名

filename = filename.substring(0, filename.indexOf(".")-1)+ dir.listFiles().length+ filename.substring(filename.indexOf("."));

file = new File(dir, filename);

}

save(id, file);

}else{// 如果上传的文件存在上传记录,读取上次的断点位置

file = new File(log.getPath());//从上传记录中得到文件的路径

if(file.exists()){

File logFile = new File(file.getParentFile(), file.getName()+".log");

if(logFile.exists()){

Properties properties = new Properties();

properties.load(new FileInputStream(logFile));

position = Integer.valueOf(properties.getProperty("length"));//读取断点位置

}

}

}

OutputStream outStream = socket.getOutputStream();

String response = "sourceid="+ id+ ";position="+ position+ "\r\n";

//服务器收到客户端的请求信息后，给客户端返回响应信息：sourceid=1274773833264;position=0

//sourceid由服务生成，唯一标识上传的文件，position指示客户端从文件的什么位置开始上传

outStream.write(response.getBytes());

RandomAccessFile fileOutStream = new RandomAccessFile(file, "rwd");

if(position==0) fileOutStream.setLength(Integer.valueOf(filelength));//设置文件长度

fileOutStream.seek(position);//移动文件指定的位置开始写入数据

byte[] buffer = new byte[1024];

int len = -1;

int length = position;

while( (len=inStream.read(buffer)) != -1){//从输入流中读取数据写入到文件中

fileOutStream.write(buffer, 0, len);

length += len;

Properties properties = new Properties();

properties.put("length", String.valueOf(length));

FileOutputStream logFile = new FileOutputStream(new File(file.getParentFile(), file.getName()+".log"));

properties.store(logFile, null);//实时记录文件的最后保存位置

logFile.close();

}

if(length==fileOutStream.length()) delete(id);

fileOutStream.close();

inStream.close();

outStream.close();

file = null;

}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

if(socket != null && !socket.isClosed()) socket.close();

} catch (IOException e) {}

}

}

}

public FileLog find(Long sourceid) {

return datas.get(sourceid);

}

// 保存上传记录

public void save(Long id, File saveFile) {

// 日后可以改成通过数据库存放

datas.put(id, new FileLog(id, saveFile.getAbsolutePath()));

}

// 当文件上传完毕，删除记录

public void delete(long sourceid) {

if (datas.containsKey(sourceid))

datas.remove(sourceid);

}

private class FileLog {

private Long id;

private String path;

public FileLog(Long id, String path) {

super();

this.id = id;

this.path = path;

}

public Long getId() {

return id;

}

public void setId(Long id) {

this.id = id;

}

public String getPath() {

return path;

}

public void setPath(String path) {

this.path = path;

}

}

}

ServerWindow.javapackage com.android.socket.server;

import java.awt.BorderLayout;

import java.awt.Frame;

import java.awt.Label;

import java.awt.event.WindowEvent;

import java.awt.event.WindowListener;

public class ServerWindow extends Frame{

private SocketServer server;

private Label label;

public ServerWindow(String title){

super(title);

server = new SocketServer(7878);

label = new Label();

add(label, BorderLayout.PAGE_START);

label.setText("服务器已经启动");

this.addWindowListener(new WindowListener() {

@Override

public void windowOpened(WindowEvent e) {

new Thread(new Runnable() {

@Override

public void run() {

try {

server.start();

} catch (Exception e) {

e.printStackTrace();

}

}

}).start();

}

@Override

public void windowIconified(WindowEvent e) {

}

@Override

public void windowDeiconified(WindowEvent e) {

}

@Override

public void windowDeactivated(WindowEvent e) {

}

@Override

public void windowClosing(WindowEvent e) {

server.quit();

System.exit(0);

}

@Override

public void windowClosed(WindowEvent e) {

}

@Override

public void windowActivated(WindowEvent e) {

}

});

}

/**

* @param args

*/

public static void main(String[] args) {

ServerWindow window = new ServerWindow("文件上传服务端");

window.setSize(300, 300);

window.setVisible(true);

}

}

StreamTool.javapackage com.android.socket.utils;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.PushbackInputStream;

public class StreamTool {

public static void save(File file, byte[] data) throws Exception {

FileOutputStream outStream = new FileOutputStream(file);

outStream.write(data);

outStream.close();

}

public static String readLine(PushbackInputStream in) throws IOException {

char buf[] = new char[128];

int room = buf.length;

int offset = 0;

int c;

loop: while (true) {

switch (c = in.read()) {

case -1:

case '\n':

break loop;

case '\r':

int c2 = in.read();

if ((c2 != '\n') && (c2 != -1)) in.unread(c2);

break loop;

default:

if (--room < 0) {

char[] lineBuffer = buf;

buf = new char[offset + 128];

room = buf.length - offset - 1;

System.arraycopy(lineBuffer, 0, buf, 0, offset);

}

buf[offset++] = (char) c;

break;

}

}

if ((c == -1) && (offset == 0)) return null;

return String.copyValueOf(buf, 0, offset);

}

/**

* 读取流

* @param inStream

* @return 字节数组

* @throws Exception

*/

public static byte[] readStream(InputStream inStream) throws Exception{

ByteArrayOutputStream outSteam = new ByteArrayOutputStream();

byte[] buffer = new byte[1024];

int len = -1;

while( (len=inStream.read(buffer)) != -1){

outSteam.write(buffer, 0, len);

}

outSteam.close();

inStream.close();

return outSteam.toByteArray();

}

}

运行效果如下:

Android前端控制:



后台监控日志:



下载后的文件路径: