本文实例为大家分享了Android实现断点续传的具体代码，供大家参考，具体内容如下
断点续传功能，在文件上传中断时，下次上传同一文件时，能在上次的断点处继续上传，可节省时间和流量
总结规划步骤：
1.给大文件分片，每一个大文件发送前，相对应的创建一个文件夹存放所有分片
2.上传接口，每一个分片上传完成就删掉，直到所有分片上传完成，再删掉存放分片的文件夹，服务器把分片合成完整的文件。
先看分片功能，传入的3个参数分别为源文件地址，分片大小，存放分片的文件夹地址。返回的是分片个数。
/**
*
* @param sourceFilePath 源文件地址
* @param partFileLength 分割文件的每一个片段大小标准
* @param splitPath 分割之后片段所在文件夹
* @return
* @throws Exception
*/
public static int splitFile(String sourceFilePath, int partFileLength, String splitPath) throws Exception {
File sourceFile = null;
File targetFile = null;
InputStream ips = null;
OutputStream ops = null;
OutputStream configOps = null;//该文件流用于存储文件分割后的相关信息，包括分割后的每个子文件的编号和路径,以及未分割前文件名
Properties partInfo = null;//properties用于存储文件分割的信息
byte[] buffer = null;
int partNumber = 1;
sourceFile = new File(sourceFilePath);//待分割文件
ips = new FileInputStream(sourceFile);//找到读取源文件并获取输入流
//创建一个存放分片的文件夹
File tempFile = new File(splitPath);
if (!tempFile.exists()) {
tempFile.mkdirs();
}
configOps = new FileOutputStream(new File(tempFile.getAbsolutePath() + File.separator + "config.properties"));
buffer = new byte[partFileLength];//开辟缓存空间
int tempLength = 0;
partInfo = new Properties();//key:1开始自动编号 value:文件路径
int sliceCount = 0;
while ((tempLength = ips.read(buffer, 0, partFileLength)) != -1) {
String targetFilePath = tempFile.getAbsolutePath() + File.separator + "part_" + (partNumber);//分割后的文件路径+文件名
sliceCount = partNumber;
partInfo.setProperty((partNumber++) + "", targetFilePath);//将相关信息存储进properties
targetFile = new File(targetFilePath);
ops = new FileOutputStream(targetFile);//分割后文件
ops.write(buffer, 0, tempLength);//将信息写入碎片文件
ops.close();//关闭碎片文件
}
partInfo.setProperty("name", sourceFile.getName());//存储源文件名
partInfo.setProperty("sliceCount", sliceCount + "");//存储分片个数
partInfo.store(configOps, "ConfigFile");//将properties存储进实体文件中
ips.close();//关闭源文件流
return sliceCount;
}
接下来，和服务器协商接口，一共2个接口
1.uploadLargeFilePre，传入参数除了常规上传文件参数之外加了分片个数sliceCount和fileHashcode。这一步是给服务器开辟存放分片的控件的，不执行上传操作，文件哈希值作为识别分片归属的唯一标准。返回int类型rCode，根据rCode结果判断是否执行第2步上传动作
2.uploadLargeFile，传入参数除了常规上传文件参数之外加了分片path，分片index，isFinished。isFinished是最后一片的依据。客户端就在上传接口的response里继续上传下一个分片，直到最后一片上传完成，服务器才会返给这个大文件的url。
看代码
protected void addFileMsg(String path) {
forceLogin();
if (path == null) {
return;
}
File file = new File(path);
if (file.exists()) {
ImMsg msg = new ImMsg();
msg.setType(ImMsg.MSG_TYPE_FILE);
msg.setTime(System.currentTimeMillis());
msg.setMsgReaded();
msg.setReceiveTime(System.currentTimeMillis());
AccountInfo accountInfo = IMApp.instance().getAccountInfo();
msg.setUserId(accountInfo.getUserId());
msg.setSex(accountInfo.getSex());
msg.setUserName(accountInfo.mNickName);
msg.setHeadUrl(accountInfo.mHead);
msg.mMasterId = mMasterId;
msg.setMsg(new File(path).getName());
msg.setPicPath(path);
msg.setState(ImMsg.STATE_SEND_UPLOADING);
String ext = null;
if (path.endsWith("doc") || path.endsWith("docx")) {
ext = "doc";
} else if (path.endsWith("xls") || path.endsWith("xlsx")) {
ext = "xls";
} else if (path.endsWith("ppt") || path.endsWith("pptx")) {
ext = "ppt";
} else if (path.endsWith("pdf")) {
ext = "pdf";
}
msg.setMsg_extend3(ext);
msg.mFileSize = (int) new File(path).length();
msg.setHasAtt(hasAtt());
addMsgToDB(msg);
isFileListSingle = fileList.size() == 1;
SPHelper spHelper = SPHelper.build();
int lastSlices = spHelper.get(slice_old, 0);
String aesPath = spHelper.get(slice_aesEncPath, "");
String lastPath = spHelper.get(slice_picPath, "");
int tempTotalCount = spHelper.get(CommonUtils.FAILED_TEMP_SEND_TOTAL_COUNT, 0);//实际发送总个数
if (lastSlices == 1 && tempTotalCount > 1) {
/**
* 读取上次失败文件的进度，如果还剩一个失败文件，但是上次发送的总文件个数大于1，
* 则fileList.size() == 1这个判断不能用，在所有判断处加一个标志
*/
isFileListSingle = false;
}
//根据文件大小，判断是否用分片上传 modify hexiaokang 2019年11月5日11点01分
if (new File(path).length() < Global.FILE_SPILT_LENGTH) {//文件小于5M,常规上传方式
upLoadFile(msg);
} else {
File sourceFile = new File(path);
//分片所在文件夹,以未做AES加密的源文件名作为 分片文件夹名字
String sliceDir = sourceFile.getParent() + File.separator + sourceFile.getName() + "_split";
if (lastSlices == 1
&& path.equals(lastPath)
&& new File(sliceDir).exists()
&& !aesPath.equals("")
&& new File(aesPath).exists()) {//发送上次的旧文件中断的分片
//只走一次
spHelper.put(slice_old, 0);
sliceIndex = spHelper.get(slice_sliceIndex, 0);
int count = spHelper.get(slice_sliceCount, 0);
LogUtil2.i(TAG + "&onUploadComplete", "sendOldFiles sliceIndex = " + sliceIndex + ", sliceCount = " + count);
largeFilePre = true;
upLoadLargeFilePre(msg, count, sliceDir, aesPath);
} else {//发送大文件正常流程
//给文件分片
int partFileLength = Global.FILE_SPILT_LENGTH;//指定分割的子文件大小为5M
//先对文件做AES加密,再进行分片,这里很重要
String aesEncPath = EncryptMgr.encFile(path, accountInfo.getEncTime(), accountInfo.getEncKey());
File f = new File(aesEncPath);
LogUtil2.i(TAG + "&onUploadComplete", "ChatMsgActivity.addFileMsg: big file enc path=" + path);
try {
sliceCount = FileSliceUtil.splitFile(aesEncPath, partFileLength, sliceDir);//将文件分割
} catch (Exception e) {
LogUtil2.e(TAG, "split.e:" + e.getMessage());
e.printStackTrace();
}
// LogUtil2.e(TAG+"&onUploadComplete", "ChatMsgActivity.addFileMsg: sliceCount:" + sliceCount);
//分片上传
largeFilePre = false;
upLoadLargeFilePre(msg, sliceCount, sliceDir, aesEncPath);
}
}
}
}
上面这一块代码，除了小文件常规上传，就是大文件上传方式了。大文件上传这里分了2种情况，
1.发送上次中断的大文件分片，这里就不用分片了，直接从sp拿到上次中断的分片count、index等信息直接上传
2.从分片到发送的全部流程，因为我这里对文件做了AES加密，所以是加密之后再分片
接下来就是上传过程
public void upLoadLargeFilePre(final ImMsg msg, final int sliceCount, final String sliceDir, final String aesEncPath) {
if (msg.getState() != ImMsg.STATE_SEND_WAITING) {
msg.setState(ImMsg.STATE_SEND_UPLOADING);
mListAdapter.notifyDataSetChanged();
}
AccountInfo accountInfo = IMApp.instance().getAccountInfo();
UploadFileHelper helper = new UploadFileHelper(accountInfo.getEncTime(), accountInfo.getEncKey(),
new UploadFileCallback() {
@Override
public void onError(Call call, Exception e) {
e.printStackTrace();
LogUtil2.e("onUploadComplete", "ChatMsgActivity.onError: error(split_upload):" + e.toString()+", call = "+call);
failCount++;
// if (msg.getPicPath() != null && msg.getPicPath().contains(SDCardUtil.getSDcardPathEx())) {
// new File(msg.getPicPath()).delete();
// }
btn_other_sendfile.setClickable(true);
CommonUtils.isSendBtnClickable = true;
Intent comIntent = new Intent();
comIntent.setAction(CommonUtils.USBFILE_COMPLETE_SEND);
comIntent.putExtra("fail_count", failCount);
sendBroadcast(comIntent);
tempProgress = 0;
largeFilePre = false;
//todo 上传失败，上传任务终止 (需要保存失败msg的信息，以及分片信息)
String picPath = msg.getPicPath();
// 保存picPath, sliceIndex, sliceCount, aesEncPath
SPHelper spHelper = SPHelper.build();
spHelper.put(slice_picPath, picPath);
spHelper.put(slice_sliceIndex, sliceIndex);
spHelper.put(slice_sliceCount, sliceCount);
spHelper.put(slice_aesEncPath, aesEncPath);
spHelper.put(slice_old, 1);//标记，1表示有上次失败的碎片，处理完上次失败的碎片之后设置为0
return;
}
@Override
public void onResponse(UploadFileAckPacket uploadFileAckPacket) {
LogUtil2.i("onUploadComplete", "ChatMsgActivity.onResponse: pre upload ack packet code="+uploadFileAckPacket.getRetCode()+", desc="+uploadFileAckPacket.getRetDesc());
if (getMsgFromDB(msg.getId()) == null) {
msg.setState(ImMsg.STATE_SEND_FAILED);
LogUtil2.i("onUploadComplete", "msg not exist d = (split_upload)" + msg.getId());
updateMsgToDB(msg);
mListAdapter.notifyDataSetChanged();
failCount++;
btn_other_sendfile.setClickable(true);
CommonUtils.isSendBtnClickable = true;
Intent comIntent = new Intent();
comIntent.setAction(CommonUtils.USBFILE_COMPLETE_SEND);
sendBroadcast(comIntent);
tempProgress = 0;
return;
}
if (uploadFileAckPacket != null && uploadFileAckPacket.isSuccess()) {
LogUtil2.i("onUploadComplete", "msg exist and sucess(uploadFileAckPacket.sliceIndex(split_upload)):" + uploadFileAckPacket.sliceIndex+", sliceCount="+sliceCount+", url="+uploadFileAckPacket.mUrl);
if (sliceIndex < sliceCount && TextUtils.isEmpty(uploadFileAckPacket.mUrl)) {
//更新进度条
if (isFileListSingle) {//单个大文件
int pro = 100 * sliceIndex / sliceCount;
Intent uploadIntent = new Intent();
uploadIntent.setAction(CommonUtils.USBFILE_PROGRESS_SEND);
uploadIntent.putExtra("sentCount", -1);//-1 代表发送的是单个文件
uploadIntent.putExtra("sentPro", pro);
sendBroadcast(uploadIntent);
} else {//一次发送多个文件，包括大文件
}
//删除掉上传成功的分片
String slicePath = sliceDir + File.separator + "part_" + (sliceIndex);
new File(slicePath).delete();
sliceIndex++;
//还有待上传的分片
upLoadLargeFilePre(msg, sliceCount, sliceDir, aesEncPath);
} else {
//所有分片上传完成
largeFilePre = false;
LogUtil2.i("onUploadComplete", "ChatMsgActivity.onResponse: 所有分片上传完成 largeFilePre="+largeFilePre);
msg.updateImageUpLoadProgress(100);
msg.setPicBigUrl(uploadFileAckPacket.mUrl);
//这里删除原文件
if (msg.getPicPath() != null && msg.getPicPath().contains(SDCardUtil.getSDcardPathEx())) {
File file = new File(msg.getPicPath());
//删除分片所在的文件夹
FileUtil.deleteFolderFile(sliceDir, true);
//删除文件
file.delete();
// EventBus.getDefault().post(new EncFileEvent(EncFileEvent.COM_FILE_DELETE, msg.getPicPath(), 0));
msg.setPicPath("");
}
if (msg.getType() == ImMsg.MSG_TYPE_IMAGE) {
msg.setPicSmallUrl(uploadFileAckPacket.mThumbnail);
msg.mThumbWidth = this.mThumbWidth;
msg.mThumbHeight = this.mThumbHeight;
}
LogUtil2.i("onUploadComplete", "msg exist and sucess(msg.getPicBigUrl()(split_upload)):" + msg.getPicBigUrl());
sendMsg(msg);
sentCount++;
sliceIndex = 1;
if (isFileListSingle) {//单个文件不用处理
} else {
//传递上传进度
Intent uploadIntent = new Intent();
uploadIntent.setAction(CommonUtils.USBFILE_PROGRESS_SEND);
uploadIntent.putExtra("sentCount", sentCount);
sendBroadcast(uploadIntent);
}
//继续上传下一个文件
if (sentCount < fileList.size()) {
addFileMsg(fileList.get(sentCount).getAbsolutePath());
} else {
//所有文件上传完成
btn_other_sendfile.setClickable(true);
CommonUtils.isSendBtnClickable = true;
Intent comIntent = new Intent();
comIntent.setAction(CommonUtils.USBFILE_COMPLETE_SEND);
sendBroadcast(comIntent);
tempProgress = 0;
}
}
} else {
LogUtil2.e("onUploadComplete", "rCode(split_upload)):" + uploadFileAckPacket.getRetCode()+", sliceIndex="+uploadFileAckPacket.sliceIndex);
if(uploadFileAckPacket.getRetCode()==1343688774){
LogUtil2.e("onUploadComplete", "ChatMsgActivity.onResponse: 缺片了！");
}
msg.setState(ImMsg.STATE_SEND_FAILED);
updateMsgToDB(msg);
if (!IMMsgMgr.notifyActivity(IMMsgMgr.IM_CMD_IMP2PMSG_ACK, msg.getUserId(), msg.hasAtt(), false, msg)) {
}
mListAdapter.notifyDataSetChanged();
}
}
@Override
public void inProgress(float progress) {
super.inProgress(progress);
// LogUtil2.i("onUploadProgress", "inProgress " + progress+", path="+msg.getPicPath()+", sliceDir="+sliceDir);
LogUtil2.i("onUploadProgress", "ChatMsgActivity.inProgress: sliceCount="+sliceCount+", sliceIndex="+sliceIndex+", sentCount="+sentCount+", list.size="+fileList.size()+", progress="+progress+", tempProgress="+tempProgress);
int pro = (int) (progress * 100);
if (new File(msg.getPicPath()).length() < Global.FILE_SPILT_LENGTH) {
//
}else{
int allPro= (int)(100*(progress+(sliceIndex-1))/sliceCount);
if (isFileListSingle && allPro - tempProgress >= 1) {
//todo 分片上传，进度条重新计算,
//多个文件上传不用考虑，这里重新计算单个文件的上传问题
LogUtil2.i("onUploadProgress", "ChatMsgActivity.inProgress: big file allPro="+allPro);
Intent uploadIntent = new Intent();
uploadIntent.setAction(CommonUtils.USBFILE_PROGRESS_SEND);
uploadIntent.putExtra("sentCount", -1);//-1代表发送的是单个文件，这里是针对用户感知而言的代码逻辑
uploadIntent.putExtra("sentPro", allPro);
tempProgress = allPro;
sendBroadcast(uploadIntent);
}
}
// 更新
mListAdapter.notifyDataSetChanged();
}
}, msg);
LogUtil2.i("onUploadComplete", "ChatMsgActivity.upLoadLargeFilePre: largeFilePre="+largeFilePre);
if (largeFilePre) {//todo 是否有过预处理
String slicePath = sliceDir + File.separator + "part_" + (sliceIndex);
int isFinished = sliceIndex == sliceCount ? 1 : 0;
helper.upLoadLargeFile(aesEncPath, slicePath, sliceIndex, isFinished);
} else {
//上传大文件 预处理
int rCode = helper.upLoadLargeFilePre(aesEncPath, sliceCount);
if (rCode == 0) {//预处理成功，可以执行上传任务
largeFilePre = true;
String slicePath = sliceDir + File.separator + "part_" + (sliceIndex);
int isFinished = sliceIndex == sliceCount ? 1 : 0;
helper.upLoadLargeFile(aesEncPath, slicePath, sliceIndex, isFinished);
} else {
//预处理失败，不执行上传任务
LogUtil2.i("onUploadComplete", "somewordsrCode:" + rCode+", before plus faileCount="+failCount);
msg.setState(ImMsg.STATE_SEND_FAILED);
updateMsgToDB(msg);
mListAdapter.notifyDataSetChanged();
failCount++;
btn_other_sendfile.setClickable(true);
CommonUtils.isSendBtnClickable = true;
Intent comIntent = new Intent();
comIntent.putExtra("upload_error", 0);
comIntent.putExtra("fail_count",failCount);
comIntent.setAction(CommonUtils.USBFILE_COMPLETE_SEND);
LogUtil.LogShow("onUploadComplete", "ChatMsgActivity.upLoadLargeFilePre: before sendIntent failCount="+failCount);
sendBroadcast(comIntent);
failCount=0;
tempProgress = 0;
}
}
}
上面这一块就是上传过程
int rCode = helper.upLoadLargeFilePre(aesEncPath, sliceCount); 这一句为第一个接口预处理，根据结果决定是否执行上传。
helper.upLoadLargeFile(aesEncPath, slicePath, sliceIndex, isFinished); 这一句执行上传，在onResponse里处理上传结果，我这里有多个文件连续上传，所以结果处理看起来有点凌乱。