代码示例：
实现文件断点续传
先编写一个服务端和客户端都会用到的流解析类：
StreamTool.java：
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();
}
} 1）服务端的实现：
socket管理与多线程管理类：
FileServer.java：
public class FileServer {
private ExecutorService executorService;//线程池
private int port;//监听端口
private boolean quit = false;//退出
private ServerSocket server;
private Map<Long, FileLog> datas = new HashMap<Long, FileLog>();//存放断点数据
public FileServer(int port){
this.port = port;
//创建线程池，池中具有(cpu个数*50)条线程
executorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * 50);
}
/**
* 退出
*/
public void quit(){
this.quit = true;
try {
server.close();
} catch (IOException e) {
}
}
/**
* 启动服务
* @throws Exception
*/
public void start() throws Exception{
server = new ServerSocket(port);
while(!quit){
try {
Socket socket = server.accept();
//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));
} catch (Exception e) {
// e.printStackTrace();
}
}
}
private final class SocketTask implements Runnable{
private Socket socket = null;
public SocketTask(Socket socket) {
this.socket = socket;
}
public void run() {
try {
System.out.println("accepted connection "+ 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){
//下面从协议数据中提取各项参数值
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();//生产资源id，如果需要唯一性，可以采用UUID
FileLog log = null;
if(sourceid!=null && !"".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("file/"+ 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{// 如果存在上传记录,读取已经上传的数据长度
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"));//读取已经上传的数据长度
}
}
}
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由服务器端生成，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);//指定从文件的特定位置开始写入数据
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);//实时记录已经接收的文件长度
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 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;
}
public FileLog(Long id, String path) {
this.id = id;
this.path = path;
}
}
} 服务端界面类:ServerWindow.java：
public class ServerWindow extends Frame {
private FileServer s = new FileServer(12345);
private Label label;
public ServerWindow(String title) {
super(title);
label = new Label();
add(label, BorderLayout.PAGE_START);
label.setText("服务器已经启动");
this.addWindowListener(new WindowListener() {
public void windowOpened(WindowEvent e) {
new Thread(new Runnable() {
public void run() {
try {
s.start();
} catch (Exception e) {
// e.printStackTrace();
}
}
}).start();
}
public void windowIconified(WindowEvent e) {
}
public void windowDeiconified(WindowEvent e) {
}
public void windowDeactivated(WindowEvent e) {
}
public void windowClosing(WindowEvent e) {
s.quit();
System.exit(0);
}
public void windowClosed(WindowEvent e) {
}
public void windowActivated(WindowEvent e) {
}
});
}
/**
* @param args
*/
public static void main(String[] args) throws IOException {
InetAddress address = InetAddress.getLocalHost();
ServerWindow window = new ServerWindow("文件上传服务端：" + address.getHostAddress());
window.setSize(400, 300);
window.setVisible(true);
}
}2）客户端(Android端)
首先是布局文件：activity_main.xml：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:padding="5dp">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="文件名"
android:textSize="18sp" />
<EditText
android:id="@+id/edit_fname"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Nikki Jamal - Priceless.mp3" />
<Button
android:id="@+id/btn_upload"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="上传" />
<Button
android:id="@+id/btn_stop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="停止" />
<ProgressBar
android:id="@+id/pgbar"
style="@android:style/Widget.ProgressBar.Horizontal"
android:layout_width="fill_parent"
android:layout_height="40px" />
<TextView
android:id="@+id/txt_result"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center" />
</LinearLayout> 因为断点续传，我们需要保存上传的进度，我们需要用到数据库，这里我们定义一个数据库 管理类：DBOpenHelper.java：：
/**
* Created by Jay on 2015/9/17 0017.
*/
public class DBOpenHelper extends SQLiteOpenHelper {
public DBOpenHelper(Context context) {
super(context, "jay.db", null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE IF NOT EXISTS uploadlog (_id integer primary key autoincrement, path varchar(20), sourceid varchar(20))");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}然后是数据库操作类：UploadHelper.java：
/**
* Created by Jay on 2015/9/17 0017.
*/
public class UploadHelper {
private DBOpenHelper dbOpenHelper;
public UploadHelper(Context context) {
dbOpenHelper = new DBOpenHelper(context);
}
public String getBindId(File file) {
SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
Cursor cursor = db.rawQuery("select sourceid from uploadlog where path=?", new String[]{file.getAbsolutePath()});
if (cursor.moveToFirst()) {
return cursor.getString(0);
}
return null;
}
public void save(String sourceid, File file) {
SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
db.execSQL("insert into uploadlog(path,sourceid) values(?,?)",
new Object[]{file.getAbsolutePath(), sourceid});
}
public void delete(File file) {
SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
db.execSQL("delete from uploadlog where path=?", new Object[]{file.getAbsolutePath()});
}
}对了，别忘了客户端也要贴上那个流解析类哦，最后就是我们的MainActivity.java了：
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private EditText edit_fname;
private Button btn_upload;
private Button btn_stop;
private ProgressBar pgbar;
private TextView txt_result;
private UploadHelper upHelper;
private boolean flag = true;
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
pgbar.setProgress(msg.getData().getInt("length"));
float num = (float) pgbar.getProgress() / (float) pgbar.getMax();
int result = (int) (num * 100);
txt_result.setText(result + "%");
if (pgbar.getProgress() == pgbar.getMax()) {
Toast.makeText(MainActivity.this, "上传成功", Toast.LENGTH_SHORT).show();
}
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bindViews();
upHelper = new UploadHelper(this);
}
private void bindViews() {
edit_fname = (EditText) findViewById(R.id.edit_fname);
btn_upload = (Button) findViewById(R.id.btn_upload);
btn_stop = (Button) findViewById(R.id.btn_stop);
pgbar = (ProgressBar) findViewById(R.id.pgbar);
txt_result = (TextView) findViewById(R.id.txt_result);
btn_upload.setOnClickListener(this);
btn_stop.setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_upload:
String filename = edit_fname.getText().toString();
flag = true;
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
File file = new File(Environment.getExternalStorageDirectory(), filename);
if (file.exists()) {
pgbar.setMax((int) file.length());
uploadFile(file);
} else {
Toast.makeText(MainActivity.this, "文件并不存在~", Toast.LENGTH_SHORT).show();
}
} else {
Toast.makeText(MainActivity.this, "SD卡不存在或者不可用", Toast.LENGTH_SHORT).show();
}
break;
case R.id.btn_stop:
flag = false;
break;
}
}
private void uploadFile(final File file) {
new Thread(new Runnable() {
public void run() {
try {
String sourceid = upHelper.getBindId(file);
Socket socket = new Socket("172.16.2.54", 12345);
OutputStream outStream = socket.getOutputStream();
String head = "Content-Length=" + file.length() + ";filename=" + file.getName()
+ ";sourceid=" + (sourceid != null ? sourceid : "") + "\r\n";
outStream.write(head.getBytes());
PushbackInputStream inStream = new PushbackInputStream(socket.getInputStream());
String response = StreamTool.readLine(inStream);
String[] items = response.split(";");
String responseSourceid = items[0].substring(items[0].indexOf("=") + 1);
String position = items[1].substring(items[1].indexOf("=") + 1);
if (sourceid == null) {//如果是第一次上传文件，在数据库中不存在该文件所绑定的资源id
upHelper.save(responseSourceid, file);
}
RandomAccessFile fileOutStream = new RandomAccessFile(file, "r");
fileOutStream.seek(Integer.valueOf(position));
byte[] buffer = new byte[1024];
int len = -1;
int length = Integer.valueOf(position);
while (flag && (len = fileOutStream.read(buffer)) != -1) {
outStream.write(buffer, 0, len);
length += len;//累加已经上传的数据长度
Message msg = new Message();
msg.getData().putInt("length", length);
handler.sendMessage(msg);
}
if (length == file.length()) upHelper.delete(file);
fileOutStream.close();
outStream.close();
inStream.close();
socket.close();
} catch (Exception e) {
Toast.makeText(MainActivity.this, "上传异常~", Toast.LENGTH_SHORT).show();
}
}
}).start();
}
}
最后，还有，记得往**AndroidManifest.xml**中写入这些权限哦！<!-- 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"/> <!-- 访问internet权限 --> <uses-permission android:name="android.permission.INTERNET"/>
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介绍
Socket服务端的编写：
服务端要做的事有这些：
Step 1：创建ServerSocket对象，绑定监听的端口
Step 2：调用accept()方法监听客户端的请求
Step 3：连接建立后，通过输入流读取客户端发送的请求信息
Step 4：通过输出流向客户端发送响应信息
Step 5：关闭相关资源
代码实现：
直接在Eclipse下创建一个Java项目，然后把Java代码贴进去即可！
public class SocketServer {
public static void main(String[] args) throws IOException {
//1.创建一个服务器端Socket，即ServerSocket，指定绑定的端口，并监听此端口
ServerSocket serverSocket = new ServerSocket(12345);
InetAddress address = InetAddress.getLocalHost();
String ip = address.getHostAddress();
Socket socket = null;
//2.调用accept()等待客户端连接
System.out.println("~~~服务端已就绪，等待客户端接入~，服务端ip地址: " + ip);
socket = serverSocket.accept();
//3.连接后获取输入流，读取客户端信息
InputStream is=null;
InputStreamReader isr=null;
BufferedReader br=null;
OutputStream os=null;
PrintWriter pw=null;
is = socket.getInputStream(); //获取输入流
isr = new InputStreamReader(is,"UTF-8");
br = new BufferedReader(isr);
String info = null;
while((info=br.readLine())!=null){//循环读取客户端的信息
System.out.println("客户端发送过来的信息" + info);
}
socket.shutdownInput();//关闭输入流
socket.close();
}
}然后我们把代码run起来，控制台会打印：
好的，接下来到Android客户端了！
4.Socket客户端的编写：
客户端要做的事有这些：
Step 1：创建Socket对象，指明需要链接的服务器的地址和端号
Step 2：链接建立后，通过输出流向服务器发送请求信息
Step 3：通过输出流获取服务器响应的信息
Step 4：关闭相关资源
代码实现：
MainActivity.java：
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn_accept = (Button) findViewById(R.id.btn_accept);
btn_accept.setOnClickListener(this);
}
@Override
public void onClick(View v) {
new Thread() {
@Override
public void run() {
try {
acceptServer();
} catch (IOException e) {
e.printStackTrace();
}
}
}.start();
}
private void acceptServer() throws IOException {
//1.创建客户端Socket，指定服务器地址和端口
Socket socket = new Socket("172.16.2.54", 12345);
//2.获取输出流，向服务器端发送信息
OutputStream os = socket.getOutputStream();//字节输出流
PrintWriter pw = new PrintWriter(os);//将输出流包装为打印流
//获取客户端的IP地址
InetAddress address = InetAddress.getLocalHost();
String ip = address.getHostAddress();
pw.write("客户端：~" + ip + "~ 接入服务器！！");
pw.flush();
socket.shutdownOutput();//关闭输出流
socket.close();
}
}因为Android不允许在主线程(UI线程)中做网络操作，所以这里需要我们自己 另开一个线程来连接Socket！
5.增强版案例：简易聊天室
只是点击个按钮，然后服务器返回一串信息，肯定是很无趣的是吧，接下来我们来 搭建一个超简单的聊天室，我们需要用到线程池，存储Socket链接的集合，我们还需要 字节写一个线程，具体的我们在代码中来体会！
实现的效果图：
先把我们的服务端跑起来：
接着把我们的程序分别跑到两台模拟器上：
接下来我们来写代码：
首先是服务端，就是将读写socket的操作放到自定义线程当中，创建ServerSocket后，循环 调用accept方法，当有新客户端接入，将socket加入集合当中，同时在线程池新建一个线程！
另外，在读取信息的方法中，对输入字符串进行判断，如果为bye字符串，将socket从集合中 移除，然后close掉！
Server.java：
public class Server {
//定义相关的参数,端口,存储Socket连接的集合,ServerSocket对象
//以及线程池
private static final int PORT = 12345;
private List<Socket> mList = new ArrayList<Socket>();
private ServerSocket server = null;
private ExecutorService myExecutorService = null;
public static void main(String[] args) {
new Server();
}
public Server()
{
try
{
server = new ServerSocket(PORT);
//创建线程池
myExecutorService = Executors.newCachedThreadPool();
System.out.println("服务端运行中...\n");
Socket client = null;
while(true)
{
client = server.accept();
mList.add(client);
myExecutorService.execute(new Service(client));
}
}catch(Exception e){e.printStackTrace();}
}
class Service implements Runnable
{
private Socket socket;
private BufferedReader in = null;
private String msg = "";
public Service(Socket socket) {
this.socket = socket;
try
{
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
msg = "用户:" +this.socket.getInetAddress() + "~加入了聊天室"
+"当前在线人数:" +mList.size();
this.sendmsg();
}catch(IOException e){e.printStackTrace();}
}
@Override
public void run() {
try{
while(true)
{
if((msg = in.readLine()) != null)
{
if(msg.equals("bye"))
{
System.out.println("~~~~~~~~~~~~~");
mList.remove(socket);
in.close();
msg = "用户:" + socket.getInetAddress()
+ "退出:" +"当前在线人数:"+mList.size();
socket.close();
this.sendmsg();
break;
}else{
msg = socket.getInetAddress() + " 说: " + msg;
this.sendmsg();
}
}
}
}catch(Exception e){e.printStackTrace();}
}
//为连接上服务端的每个客户端发送信息
public void sendmsg()
{
System.out.println(msg);
int num = mList.size();
for(int index = 0;index < num;index++)
{
Socket mSocket = mList.get(index);
PrintWriter pout = null;
try {
pout = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(mSocket.getOutputStream(),"UTF-8")),true);
pout.println(msg);
}catch (IOException e) {e.printStackTrace();}
}
}
}
}接着到客户端，客户端的难点在于要另外开辟线程的问题，因为Android不允许直接在 主线程中做网络操作，而且不允许在主线程外的线程操作UI，这里的做法是自己新建 一个线程，以及通过Hanlder来更新UI，实际开发不建议直接这样做！！！
布局文件:activity_main.xml：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="小猪简易聊天室" />
<TextView
android:id="@+id/txtshow"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<EditText
android:id="@+id/editsend"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<Button
android:id="@+id/btnsend"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="发送"
/>
</LinearLayout>MainActivity.java：
public class MainActivity extends AppCompatActivity implements Runnable {
//定义相关变量,完成初始化
private TextView txtshow;
private EditText editsend;
private Button btnsend;
private static final String HOST = "172.16.2.54";
private static final int PORT = 12345;
private Socket socket = null;
private BufferedReader in = null;
private PrintWriter out = null;
private String content = "";
private StringBuilder sb = null;
//定义一个handler对象,用来刷新界面
public Handler handler = new Handler() {
public void handleMessage(Message msg) {
if (msg.what == 0x123) {
sb.append(content);
txtshow.setText(sb.toString());
}
}
;
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sb = new StringBuilder();
txtshow = (TextView) findViewById(R.id.txtshow);
editsend = (EditText) findViewById(R.id.editsend);
btnsend = (Button) findViewById(R.id.btnsend);
//当程序一开始运行的时候就实例化Socket对象,与服务端进行连接,获取输入输出流
//因为4.0以后不能再主线程中进行网络操作,所以需要另外开辟一个线程
new Thread() {
public void run() {
try {
socket = new Socket(HOST, PORT);
in = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF-8"));
out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(
socket.getOutputStream())), true);
} catch (IOException e) {
e.printStackTrace();
}
}
}.start();
//为发送按钮设置点击事件
btnsend.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String msg = editsend.getText().toString();
if (socket.isConnected()) {
if (!socket.isOutputShutdown()) {
out.println(msg);
}
}
}
});
new Thread(MainActivity.this).start();
}
//重写run方法,在该方法中输入流的读取
@Override
public void run() {
try {
while (true) {
if (socket.isConnected()) {
if (!socket.isInputShutdown()) {
if ((content = in.readLine()) != null) {
content += "\n";
handler.sendEmptyMessage(0x123);
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}版权声明：本文为qq_15204179原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接和本声明。