前言
之前项目需要上传大文件的功能，上传大文件经常遇到上传一半由于网络或者其他一些原因上传失败。然后又得重新上传（很麻烦），所以就想能不能做个断点上传的功能。于是网上搜索，发现市面上很少有断点上传的案例，有找到一个案例也是采用SOCKET作为上传方式（大文件上传，不适合使用POST,GET形式）。由于大文件夹不适合http上传的方式，所以就想能不能把大文件切割成n块小文件，然后上传这些小文件，所有小文件全部上传成功后再在服务器上进行拼接。这样不就可以实现断点上传，又解决了http不适合上传大文件的难题了吗！！！
原理分析
Android客户端
首先，android端调用服务器接口1，参数为filename（服务器标识判断是否上传过）
如果存在filename，说明之前上传过，则续传；如果没有，则从零开始上传。
然后，android端调用服务器接口2，传入参数name，chunck（传到第几块），chuncks（总共多少块）
服务器端
接口一：根据上传文件名称filename 判断是否之前上传过，没有则返回客户端chunck=1，有则读取记录chunck并返回。
接口二：上传文件，如果上传块数chunck=chuncks，遍历所有块文件拼接成一个完整文件。
服务端源代码
服务器接口1
@WebServlet(urlPatterns = { "/ckeckFileServlet" })
public class CkeckFileServlet extends HttpServlet {
private FileUploadStatusServiceI statusService;
String repositoryPath;
String uploadPath;
@Override
public void init(ServletConfig config) throws ServletException {
ServletContext servletContext = config.getServletContext();
WebApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(servletContext);
statusService = (FileUploadStatusServiceI) context.getBean("fileUploadStatusServiceImpl");
repositoryPath = FileUtils.getTempDirectoryPath();
uploadPath = config.getServletContext().getRealPath("datas/uploader");
File up = new File(uploadPath);
if (!up.exists()) {
up.mkdir();
}
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// TODO Auto-generated method stub
String fileName = new String(req.getParameter("filename"));
//String chunk = req.getParameter("chunk");
//System.out.println(chunk);
System.out.println(fileName);
resp.setContentType("text/json; charset=utf-8");
TfileUploadStatus file = statusService.get(fileName);
try {
if (file != null) {
int schunk = file.getChunk();
deleteFile(uploadPath + schunk + "_" + fileName);
//long off = schunk * Long.parseLong(chunkSize);
resp.getWriter().write("{\"off\":" + schunk + "}");
} else {
resp.getWriter().write("{\"off\":1}");
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
服务器接口2
@WebServlet(urlPatterns = { "/uploaderWithContinuinglyTransferring" })
public class UploaderServletWithContinuinglyTransferring extends HttpServlet {
private static final long serialVersionUID = 1L;
private FileUploadStatusServiceI statusService;
String repositoryPath;
String uploadPath;
@Override
public void init(ServletConfig config) throws ServletException {
ServletContext servletContext = config.getServletContext();
WebApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(servletContext);
statusService = (FileUploadStatusServiceI) context.getBean("fileUploadStatusServiceImpl");
repositoryPath = FileUtils.getTempDirectoryPath();
System.out.println("临时目录：" + repositoryPath);
uploadPath = config.getServletContext().getRealPath("datas/uploader");
System.out.println("目录：" + uploadPath);
File up = new File(uploadPath);
if (!up.exists()) {
up.mkdir();
}
}
@SuppressWarnings("unchecked")
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
Integer schunk = null;// 分割块数
Integer schunks = null;// 总分割数
String name = null;// 文件名
BufferedOutputStream outputStream = null;
if (ServletFileUpload.isMultipartContent(request)) {
try {
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setSizeThreshold(1024);
factory.setRepository(new File(repositoryPath));// 设置临时目录
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setHeaderEncoding("UTF-8");
upload.setSizeMax(5 * 1024 * 1024 * 1024);// 设置附近大小
List<FileItem> items = upload.parseRequest(request);
// 生成新文件名
String newFileName = null;
for (FileItem item : items) {
if (!item.isFormField()) {// 如果是文件类型
name = newFileName;// 获得文件名
if (name != null) {
String nFname = newFileName;
if (schunk != null) {
nFname = schunk + "_" + name;
}
File savedFile = new File(uploadPath, nFname);
item.write(savedFile);
}
} else {
// 判断是否带分割信息
if (item.getFieldName().equals("chunk")) {
schunk = Integer.parseInt(item.getString());
//System.out.println(schunk);
}
if (item.getFieldName().equals("chunks")) {
schunks = Integer.parseInt(item.getString());
}
if (item.getFieldName().equals("name")) {
newFileName = new String(item.getString());
}
}
}
//System.out.println(schunk + "/" + schunks);
if (schunk != null && schunk == 1) {
TfileUploadStatus file = statusService.get(newFileName);
if (file != null) {
statusService.updateChunk(newFileName, schunk);
} else {
statusService.add(newFileName, schunk, schunks);
}
} else {
TfileUploadStatus file = statusService.get(newFileName);
if (file != null) {
statusService.updateChunk(newFileName, schunk);
}
}
if (schunk != null && schunk.intValue() == schunks.intValue()) {
outputStream = new BufferedOutputStream(new FileOutputStream(new File(uploadPath, newFileName)));
// 遍历文件合并
for (int i = 1; i <= schunks; i++) {
//System.out.println("文件合并:" + i + "/" + schunks);
File tempFile = new File(uploadPath, i + "_" + name);
byte[] bytes = FileUtils.readFileToByteArray(tempFile);
outputStream.write(bytes);
outputStream.flush();
tempFile.delete();
}
outputStream.flush();
}
response.getWriter().write("{\"status\":true,\"newName\":\"" + newFileName + "\"}");
} catch (FileUploadException e) {
e.printStackTrace();
response.getWriter().write("{\"status\":false}");
} catch (Exception e) {
e.printStackTrace();
response.getWriter().write("{\"status\":false}");
} finally {
try {
if (outputStream != null)
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
android端源码
UploadTask 上传线程类
package com.mainaer.wjoklib.okhttp.upload;
import android.database.sqlite.SQLiteDatabase;
import android.os.Environment;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.text.TextUtils;
import java.io.Closeable;
import java.io.File;
import java.io.IOException;
import java.text.DecimalFormat;
import java.util.HashMap;
import java.util.Map;
import okhttp3.Headers;
import okhttp3.MediaType;
import okhttp3.MultipartBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
/**
* 上传线程
*
* @author hst
* @date 2016/9/6 .
*/
public class UploadTask implements Runnable {
private static String FILE_MODE = "rwd";
private OkHttpClient mClient;
private SQLiteDatabase db;
private UploadTaskListener mListener;
private Builder mBuilder;
private String id;// task id
private String url;// file url
private String fileName; // File name when saving
private int uploadStatus;
private int chunck, chuncks;//流块
private int position;
private int errorCode;
static String BOUNDARY = "----------" + System.currentTimeMillis();
public static final MediaType MEDIA_TYPE_MARKDOWN = MediaType.parse("multipart/form-data;boundary=" + BOUNDARY);
private UploadTask(Builder builder) {
mBuilder = builder;
mClient = new OkHttpClient();
this.id = mBuilder.id;
this.url = mBuilder.url;
this.fileName = mBuilder.fileName;
this.uploadStatus = mBuilder.uploadStatus;
this.chunck = mBuilder.chunck;
this.setmListener(mBuilder.listener);
// 以kb为计算单位
}
@Override
public void run() {
try {
int blockLength = 1024 * 1024;
File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+ File.separator +fileName);
if (file.length() % blockLength == 0) {
chuncks = (int) file.length() / blockLength;
} else {
chuncks = (int) file.length() / blockLength + 1;
}
while (chunck <= chuncks&&uploadStatus!= UploadStatus.UPLOAD_STATUS_PAUSE&&uploadStatus!= UploadStatus.UPLOAD_STATUS_ERROR)
{
uploadStatus = UploadStatus.UPLOAD_STATUS_UPLOADING;
Map<String, String> params = new HashMap<String, String>();
params.put("name", fileName);
params.put("chunks", chuncks + "");
params.put("chunk", chunck + "");
final byte[] mBlock = FileUtils.getBlock((chunck - 1) * blockLength, file, blockLength);
MultipartBody.Builder builder = new MultipartBody.Builder()
.setType(MultipartBody.FORM);
addParams(builder, params);
RequestBody requestBody = RequestBody.create(MEDIA_TYPE_MARKDOWN, mBlock);
builder.addFormDataPart("mFile", fileName, requestBody);
Request request = new Request.Builder()
.url(url+ "uploaderWithContinuinglyTransferring")
.post(builder.build())
.build();
Response response = null;
response = mClient.newCall(request).execute();
if (response.isSuccessful()) {
onCallBack();
chunck++;
/* if (chunck <= chuncks) {
run();
}*/
}
else
{
uploadStatus = UploadStatus.UPLOAD_STATUS_ERROR;
onCallBack();
}
}
} catch (IOException e) {
uploadStatus = UploadStatus.UPLOAD_STATUS_ERROR;
onCallBack();
e.printStackTrace();
}
}
/* *//**
* 删除数据库文件和已经上传的文件
*//*
public void cancel() {
if (mListener != null)
mListener.onCancel(UploadTask.this);
}*/
/**
* 分发回调事件到ui层
*/
private void onCallBack() {
mHandler.sendEmptyMessage(uploadStatus);
// 同步manager中的task信息
//UploadManager.getInstance().updateUploadTask(this);
}
Handler mHandler = new Handler(Looper.getMainLooper()) {
@Override
public void handleMessage(Message msg) {
int code = msg.what;
switch (code) {
// 上传失败
case UploadStatus.UPLOAD_STATUS_ERROR:
mListener.onError(UploadTask.this, errorCode,position);
break;
// 正在上传
case UploadStatus.UPLOAD_STATUS_UPLOADING:
mListener.onUploading(UploadTask.this, getDownLoadPercent(), position);
// 暂停上传
break;
case UploadStatus.UPLOAD_STATUS_PAUSE:
mListener.onPause(UploadTask.this);
break;
}
}
};
private String getDownLoadPercent() {
String baifenbi = "0";// 接受百分比的值
if (chunck >= chuncks) {
return "100";
}
double baiy = chunck * 1.0;
double baiz = chuncks * 1.0;
// 防止分母为0出现NoN
if (baiz > 0) {
double fen = (baiy / baiz) * 100;
//NumberFormat nf = NumberFormat.getPercentInstance();
//nf.setMinimumFractionDigits(2); //保留到小数点后几位
// 百分比格式，后面不足2位的用0补齐
//baifenbi = nf.format(fen);
//注释掉的也是一种方法
DecimalFormat df1 = new DecimalFormat("0");//0.00
baifenbi = df1.format(fen);
}
return baifenbi;
}
private String getFileNameFromUrl(String url) {
if (!TextUtils.isEmpty(url)) {
return url.substring(url.lastIndexOf("/") + 1);
}
return System.currentTimeMillis() + "";
}
private void close(Closeable closeable) {
try {
closeable.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public void setClient(OkHttpClient mClient) {
this.mClient = mClient;
}
public Builder getBuilder() {
return mBuilder;
}
public void setBuilder(Builder builder) {
this.mBuilder = builder;
}
public String getId() {
if (!TextUtils.isEmpty(id)) {
} else {
id = url;
}
return id;
}
public String getUrl() {
return url;
}
public String getFileName() {
return fileName;
}
public void setUploadStatus(int uploadStatus) {
this.uploadStatus = uploadStatus;
}
public int getUploadStatus() {
return uploadStatus;
}
public void setmListener(UploadTaskListener mListener) {
this.mListener = mListener;
}
public static class Builder {
private String id;// task id
private String url;// file url
private String fileName; // File name when saving
private int uploadStatus = UploadStatus.UPLOAD_STATUS_INIT;
private int chunck;//第几块
private UploadTaskListener listener;
/**
* 作为上传task开始、删除、停止的key值，如果为空则默认是url
*
* @param id
* @return
*/
public Builder setId(String id) {
this.id = id;
return this;
}
/**
* 上传url（not null）
*
* @param url
* @return
*/
public Builder setUrl(String url) {
this.url = url;
return this;
}
/**
* 设置上传状态
*
* @param uploadStatus
* @return
*/
public Builder setUploadStatus(int uploadStatus) {
this.uploadStatus = uploadStatus;
return this;
}
/**
* 第几块
*
* @param chunck
* @return
*/
public Builder setChunck(int chunck) {
this.chunck = chunck;
return this;
}
/**
* 设置文件名
*
* @param fileName
* @return
*/
public Builder setFileName(String fileName) {
this.fileName = fileName;
return this;
}
/**
* 设置上传回调
*
* @param listener
* @return
*/
public Builder setListener(UploadTaskListener listener) {
this.listener = listener;
return this;
}
public UploadTask build() {
return new UploadTask(this);
}
}
private void addParams(MultipartBody.Builder builder, Map<String, String> params) {
if (params != null && !params.isEmpty()) {
for (String key : params.keySet()) {
builder.addPart(Headers.of("Content-Disposition", "form-data; name=\"" + key + "\""),
RequestBody.create(null, params.get(key)));
}
}
}
}
UploadManager上传管理器
package com.mainaer.wjoklib.okhttp.upload;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import okhttp3.OkHttpClient;
/**
* 上传管理器
*
* @author wangjian
* @date 2016/5/13 .
*/
public class UploadManager {
private static Context mContext;
private static SQLiteDatabase db;
private OkHttpClient mClient;
private int mPoolSize = 20;
// 将执行结果保存在future变量中
private Map<string, future=""> mFutureMap;
private ExecutorService mExecutor;
private Map<string, uploadtask=""> mCurrentTaskList;
static UploadManager manager;
/**
* 方法加锁，防止多线程操作时出现多个实例
*/
private static synchronized void init() {
if (manager == null) {
manager = new UploadManager();
}
}
/**
* 获得当前对象实例
*
* @return 当前实例对象
*/
public final static UploadManager getInstance() {
if (manager == null) {
init();
}
return manager;
}
/**
* 管理器初始化，建议在application中调用
*
* @param context
*/
public static void init(Context context, SQLiteDatabase db1) {
mContext = context;
db = db1;
getInstance();
}
public UploadManager() {
initOkhttpClient();
// 初始化线程池
mExecutor = Executors.newFixedThreadPool(mPoolSize);
mFutureMap = new HashMap<>();
mCurrentTaskList = new HashMap<>();
}
/**
* 初始化okhttp
*/
private void initOkhttpClient() {
OkHttpClient.Builder okBuilder = new OkHttpClient.Builder();
okBuilder.connectTimeout(1000, TimeUnit.SECONDS);
okBuilder.readTimeout(1000, TimeUnit.SECONDS);
okBuilder.writeTimeout(1000, TimeUnit.SECONDS);
mClient = okBuilder.build();
}
/**
* 添加上传任务
*
* @param uploadTask
*/
public void addUploadTask(UploadTask uploadTask) {
if (uploadTask != null && !isUploading(uploadTask)) {
uploadTask.setClient(mClient);
uploadTask.setUploadStatus(UploadStatus.UPLOAD_STATUS_INIT);
// 保存上传task列表
mCurrentTaskList.put(uploadTask.getId(), uploadTask);
Future future = mExecutor.submit(uploadTask);
mFutureMap.put(uploadTask.getId(), future);
}
}
private boolean isUploading(UploadTask task) {
if (task != null) {
if (task.getUploadStatus() == UploadStatus.UPLOAD_STATUS_UPLOADING) {
return true;
}
}
return false;
}
/**
* 暂停上传任务
*
* @param id 任务id
*/
public void pause(String id) {
UploadTask task = getUploadTask(id);
if (task != null) {
task.setUploadStatus(UploadStatus.UPLOAD_STATUS_PAUSE);
}
}
/**
* 重新开始已经暂停的上传任务
*
* @param id 任务id
*/
public void resume(String id, UploadTaskListener listener) {
UploadTask task = getUploadTask(id);
if (task != null) {
addUploadTask(task);
}
}
/* *//**
* 取消上传任务(同时会删除已经上传的文件，和清空数据库缓存)
*
* @param id 任务id
* @param listener
*//*
public void cancel(String id, UploadTaskListener listener) {
UploadTask task = getUploadTask(id);
if (task != null) {
mCurrentTaskList.remove(id);
mFutureMap.remove(id);
task.setmListener(listener);
task.cancel();
task.setDownloadStatus(UploadStatus.DOWNLOAD_STATUS_CANCEL);
}
}*/
/**
* 实时更新manager中的task信息
*
* @param task
*/
public void updateUploadTask(UploadTask task) {
if (task != null) {
UploadTask currTask = getUploadTask(task.getId());
if (currTask != null) {
mCurrentTaskList.put(task.getId(), task);
}
}
}
/**
* 获得指定的task
*
* @param id task id
* @return
*/
public UploadTask getUploadTask(String id) {
UploadTask currTask = mCurrentTaskList.get(id);
if (currTask == null) {
currTask = parseEntity2Task(new UploadTask.Builder().build());
// 放入task list中
mCurrentTaskList.put(id, currTask);
}
return currTask;
}
private UploadTask parseEntity2Task(UploadTask currTask) {
UploadTask.Builder builder = new UploadTask.Builder()//
.setUploadStatus(currTask.getUploadStatus())
.setFileName(currTask.getFileName())//
.setUrl(currTask.getUrl())
.setId(currTask.getId());
currTask.setBuilder(builder);
return currTask;
}
}
FileUtils文件分块类
package com.mainaer.wjoklib.okhttp.upload;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
public class FileUtils {
public static byte[] getBlock(long offset, File file, int blockSize) {
byte[] result = new byte[blockSize];
RandomAccessFile accessFile = null;
try {
accessFile = new RandomAccessFile(file, "r");
accessFile.seek(offset);
int readSize = accessFile.read(result);
if (readSize == -1) {
return null;
} else if (readSize == blockSize) {
return result;
} else {
byte[] tmpByte = new byte[readSize];
System.arraycopy(result, 0, tmpByte, 0, readSize);
return tmpByte;
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (accessFile != null) {
try {
accessFile.close();
} catch (IOException e1) {
}
}
}
return null;
}
}
UploadTaskListener 接口类
package com.mainaer.wjoklib.okhttp.upload;
import com.mainaer.wjoklib.okhttp.download.DownloadStatus;
import java.io.File;
/**
* Created by hst on 16/9/21.
*/
public interface UploadTaskListener {
/**
* 上传中
*
* @param percent
* @param uploadTask
*/
void onUploading(UploadTask uploadTask, String percent,int position)
/**
* 上传成功
*
* @param file
* @param uploadTask
*/
void onUploadSuccess(UploadTask uploadTask, File file);
/**
* 上传失败
*
* @param uploadTask
* @param errorCode {@link DownloadStatus}
*/
void onError(UploadTask uploadTask, int errorCode,int position);
/**
* 上传暂停
*
* @param uploadTask
*
*/
void onPause(UploadTask uploadTask);
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持找一找教程网。
