在Android中除了通过http协议上传小文件外,还可以通过Socket上传较大的文件
案例具体思路:
文件被第一次上传时发送: "Content-Length="+ uploadFile.length() + ";filename="+ uploadFile.getName() + ";sourceid="+null+"\r\n";字段给服务器
服务器收到字段后,看到文件的sourceid字段值为空,则表示该文件第一次上传,服务器就会自动为其创建id,并且在本地根据文件名建立相应文件用于接收文件数据,同时把该文件路径和id保存在Map集合中,并发送:“sourceid="+ id+ ";position=0\r\n";内容给客户端,客户端收到服务器为其创建的id和应该从上传文件的什么位置开始读取信息后,在SQLite数据库中记录下本次上传文件的id和文件路径,然后上传文件。
服务器端则开始接收从客户端发来的数据并保存起来,并且时刻把该文件的上传的数据大小保存在以该文件命名的.log文件中。
当在发送的的时候突然关机或网络出现状况,当再次上传该文件时,客户端就会从SQLite中根据文件路径查找到已上传文件的id,然后发送内容给服务器端,服务器从发来的sourceid字段中读到了数据,就从map集合中找到该文件路径,然后根据路径和文件名找到.log文件,并从中读取上次上传文件的大小发送给客户端,客户端得到后遍选择从文件的指定文件读取上传,服务器则再次接收并从文件指定位置保存。
服务器端代码:
界面代码:
public class ServerWindow extends Frame{
private FileServer s = new FileServer(7878);
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() {
@Override
public void windowOpened(WindowEvent e) {
new Thread(new Runnable() {
@Override
public void run() {
try {
s.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) {
s.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);
}
}
主要类FileServer的代码
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;
}
@Override
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("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 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;
}
}
}
工具类StreamTool代码
public class StreamTool {
// 读取从客户端发来的 "Content-Length="+ uploadFile.length() + ";filename="+ uploadFile.getName() + ";sourceid="+(souceid==null? "" : souceid)+"\r\n";
// 读到回车换行前面的内容
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);
}
}
Android客户端的界面:
Android客户端主要负责上传的代码:
按钮点击后调用uploadFile方法上传文件
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
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();
}
}
});
uploadFile方法:
private void uploadFile(final File uploadFile) {
new Thread(new Runnable() {
@Override
public void run() {
try {
uploadbar.setMax((int)uploadFile.length()); // 设置进度条
String souceid = logService.getBindId(uploadFile); //调用logService获取文件的id,第一次上传没有记录会得到null
String head = "Content-Length="+ uploadFile.length() + ";filename="+ uploadFile.getName() + ";sourceid="+
(souceid==null? "" : souceid)+"\r\n";
Socket socket = new Socket("172.19.68.65", 7878); // 建立socket连接
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)); // 设置文件读取的位置
byte[] buffer = new byte[1024];
int len = -1;
int length = Integer.valueOf(position);
while( (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();
}
UploadLogService的主要方法
public class UploadLogService {
private DBOpenHelper dbOpenHelper;
public UploadLogService(Context context){
this.dbOpenHelper = new DBOpenHelper(context);
}
// 保存文件的id和文件路径
public void save(String sourceid, File uploadFile){
SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
db.execSQL("insert into uploadlog(uploadfilepath, sourceid) values(?,?)",
new Object[]{uploadFile.getAbsolutePath(),sourceid});
}
// 删除该文件记录
public void delete(File uploadFile){
SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
db.execSQL("delete from uploadlog where uploadfilepath=?", new Object[]{uploadFile.getAbsolutePath()});
}
// 根据文件路径获取文件id
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;
}
}