用java向hdfs上傳文件時，如何實現(xiàn)斷點續(xù)傳

@Component("javaLargeFileUploaderServlet")

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@WebServlet(name = "javaLargeFileUploaderServlet", urlPatterns = { "/javaLargeFileUploaderServlet" })

public class UploadServlet extends HttpRequestHandlerServlet

implements HttpRequestHandler {

private static final Logger log = LoggerFactory.getLogger(UploadServlet.class);

@Autowired

UploadProcessor uploadProcessor;

@Autowired

FileUploaderHelper fileUploaderHelper;

@Autowired

ExceptionCodeMappingHelper exceptionCodeMappingHelper;

@Autowired

Authorizer authorizer;

@Autowired

StaticStateIdentifierManager staticStateIdentifierManager;

@Override

public void handleRequest(HttpServletRequest request, HttpServletResponse response)

throws IOException {

log.trace("Handling request");

Serializable jsonObject = null;

try {

// extract the action from the request

UploadServletAction actionByParameterName =

UploadServletAction.valueOf(fileUploaderHelper.getParameterValue(request, UploadServletParameter.action));

// check authorization

checkAuthorization(request, actionByParameterName);

// then process the asked action

jsonObject = processAction(actionByParameterName, request);

// if something has to be written to the response

if (jsonObject != null) {

fileUploaderHelper.writeToResponse(jsonObject, response);

}

}

// If exception, write it

catch (Exception e) {

exceptionCodeMappingHelper.processException(e, response);

}

}

private void checkAuthorization(HttpServletRequest request, UploadServletAction actionByParameterName)

throws MissingParameterException, AuthorizationException {

// check authorization

// if its not get progress (because we do not really care about authorization for get

// progress and it uses an array of file ids)

if (!actionByParameterName.equals(UploadServletAction.getProgress)) {

// extract uuid

final String fileIdFieldValue = fileUploaderHelper.getParameterValue(request, UploadServletParameter.fileId, false);

// if this is init, the identifier is the one in parameter

UUID clientOrJobId;

String parameter = fileUploaderHelper.getParameterValue(request, UploadServletParameter.clientId, false);

if (actionByParameterName.equals(UploadServletAction.getConfig) parameter != null) {

clientOrJobId = UUID.fromString(parameter);

}

// if not, get it from manager

else {

clientOrJobId = staticStateIdentifierManager.getIdentifier();

}

// call authorizer

authorizer.getAuthorization(

request,

actionByParameterName,

clientOrJobId,

fileIdFieldValue != null ? getFileIdsFromString(fileIdFieldValue).toArray(new UUID[] {}) : null);

}

}

private Serializable processAction(UploadServletAction actionByParameterName, HttpServletRequest request)

throws Exception {

log.debug("Processing action " + actionByParameterName.name());

Serializable returnObject = null;

switch (actionByParameterName) {

case getConfig:

String parameterValue = fileUploaderHelper.getParameterValue(request, UploadServletParameter.clientId, false);

returnObject =

uploadProcessor.getConfig(

parameterValue != null ? UUID.fromString(parameterValue) : null);

break;

case verifyCrcOfUncheckedPart:

returnObject = verifyCrcOfUncheckedPart(request);

break;

case prepareUpload:

returnObject = prepareUpload(request);

break;

case clearFile:

uploadProcessor.clearFile(UUID.fromString(fileUploaderHelper.getParameterValue(request, UploadServletParameter.fileId)));

break;

case clearAll:

uploadProcessor.clearAll();

break;

case pauseFile:

ListUUID uuids = getFileIdsFromString(fileUploaderHelper.getParameterValue(request, UploadServletParameter.fileId));

uploadProcessor.pauseFile(uuids);

break;

case resumeFile:

returnObject =

uploadProcessor.resumeFile(UUID.fromString(fileUploaderHelper.getParameterValue(request, UploadServletParameter.fileId)));

break;

case setRate:

uploadProcessor.setUploadRate(UUID.fromString(fileUploaderHelper.getParameterValue(request, UploadServletParameter.fileId)),

Long.valueOf(fileUploaderHelper.getParameterValue(request, UploadServletParameter.rate)));

break;

case getProgress:

returnObject = getProgress(request);

break;

}

return returnObject;

}

ListUUID getFileIdsFromString(String fileIds) {

String[] splittedFileIds = fileIds.split(",");

ListUUID uuids = Lists.newArrayList();

for (int i = 0; i splittedFileIds.length; i++) {

uuids.add(UUID.fromString(splittedFileIds[i]));

}

return uuids;

}

private Serializable getProgress(HttpServletRequest request)

throws MissingParameterException {

Serializable returnObject;

String[] ids =

new Gson()

.fromJson(fileUploaderHelper.getParameterValue(request, UploadServletParameter.fileId), String[].class);

CollectionUUID uuids = Collections2.transform(Arrays.asList(ids), new FunctionString, UUID() {

@Override

public UUID apply(String input) {

return UUID.fromString(input);

}

});

returnObject = Maps.newHashMap();

for (UUID fileId : uuids) {

try {

ProgressJson progress = uploadProcessor.getProgress(fileId);

((HashMapString, ProgressJson) returnObject).put(fileId.toString(), progress);

}

catch (FileNotFoundException e) {

log.debug("No progress will be retrieved for " + fileId + " because " + e.getMessage());

}

}

return returnObject;

}

private Serializable prepareUpload(HttpServletRequest request)

throws MissingParameterException, IOException {

// extract file information

PrepareUploadJson[] fromJson =

new Gson()

.fromJson(fileUploaderHelper.getParameterValue(request, UploadServletParameter.newFiles), PrepareUploadJson[].class);

// prepare them

final HashMapString, UUID prepareUpload = uploadProcessor.prepareUpload(fromJson);

// return them

return Maps.newHashMap(Maps.transformValues(prepareUpload, new FunctionUUID, String() {

public String apply(UUID input) {

return input.toString();

};

}));

}

private Boolean verifyCrcOfUncheckedPart(HttpServletRequest request)

throws IOException, MissingParameterException, FileCorruptedException, FileStillProcessingException {

UUID fileId = UUID.fromString(fileUploaderHelper.getParameterValue(request, UploadServletParameter.fileId));

try {

uploadProcessor.verifyCrcOfUncheckedPart(fileId,

fileUploaderHelper.getParameterValue(request, UploadServletParameter.crc));

}

catch (InvalidCrcException e) {

// no need to log this exception, a fallback behaviour is defined in the

// throwing method.

// but we need to return something!

return Boolean.FALSE;

}

return Boolean.TRUE;

}

}

java web斷點續(xù)傳,我用的是fileupload來做的上傳。

使用Struts2上傳文件：

Struts文件上傳需要使用File Upload Filter。Filter Upload Filter使用一些默認的規(guī)則：

Form中的s:file name="image"/s:file標簽對應著Action類中的三個屬性分別是：上傳文件（java.io.File類型），文件名（java.lang.String類型），文件類型（java.lang.String類型，例如：image/jpeg）。命名規(guī)約為：

文件：名字與s:file標簽中的name屬性一致，這里為：image

文件名：文件 + FileName，這里為：imageFileName

文件類型：文件 + ContentType，這里為：imageContentType

所以針對上述s:file name="image"/s:file表示啊的上傳文件的JSP和Action類被別為：

imageUpload.jsp：

[html]?view plain?copy

%@?page?contentType="text/html;charset=UTF-8"?language="java"?%

%@taglib?prefix="s"?uri="/struts-tags"?%

html

headtitleImage?Upload/title/head

body

h1?Image?Upload?Page?/h1

s:form?action="imageUpload"?method="post"?enctype="multipart/form-data"

s:file?name="image"/s:file

s:submit/s:submit

/s:form

/body

/html

ImageUploadAction.java：

[html]?view plain?copy

package?com.jpleasure;

import?com.opensymphony.xwork2.ActionSupport;

import?java.io.File;

import?java.io.InputStream;

import?java.io.FileInputStream;

import?java.io.FileNotFoundException;

public?class?ImageUploadAction?extends?ActionSupport?{

private?File?image;

private?String?imageFileName;

private?String?imageContentType;

public?File?getImage()?{

return?image;

}

public?void?setImage(File?image)?{

this.image?=?image;

}

public?String?getImageFileName()?{

return?imageFileName;

}

public?void?setImageFileName(String?imageFileName)?{

this.imageFileName?=?imageFileName;

}

public?String?getImageContentType()?{

return?imageContentType;

}

public?void?setImageContentType(String?imageContentType)?{

this.imageContentType?=?imageContentType;

}

public?String?execute()?{

if?(image?!=?null)?{

System.out.println("file?name?is:"?+?this.imageFileName);

System.out.println("file?content?type?is:"?+?this.imageContentType);

System.out.println("file?length?is:"?+?this.image.length());

}

return?SUCCESS;

}

}

Struts.xml配置文件：

[html]?view plain?copy

action?name="imageUpload"?class="com.jpleasure.ImageUploadAction"

result/success.jsp/result

/action

這樣當我們選中上傳文件，提交的時候：文件內(nèi)容會以File類型的方式放在image聲明的變量中。文件的名字將會被放在imageFileName命名的變量中，文件的類型被放在imageContentType命名的變量中。

文件下載：

文件下載需要使用一個特殊的Result，stream類型的Result。Stream類型的Result主要用來處理文件下載操作。

處理原理為：所有的下載文件都是將一個二進制的流寫入到HttpResponse中去。在Action類中定義一個InputSream類型的二進制流，在Result返回給用戶的時候返回給用戶。

擴展上述的代碼，將上傳來的文件直接下載給用戶：

ImageUploadAction中需要追加一個InputSream類型的對象，并且指向上傳的文件，代碼如下，紅色部分表示變化：

[html]?view plain?copy

package?com.jpleasure;

import?com.opensymphony.xwork2.ActionSupport;

import?java.io.File;

import?java.io.InputStream;

import?java.io.FileInputStream;

import?java.io.FileNotFoundException;

public?class?ImageUploadAction?extends?ActionSupport?{

private?File?image;

private?String?imageFileName;

private?String?imageContentType;

private?InputStream?imageInputStream?=?null;

public?InputStream?getImageInputStream()?{

return?imageInputStream;

}

public?void?setImageInputStream(InputStream?imageInputStream)?{

this.imageInputStream?=?imageInputStream;

}

public?File?getImage()?{

return?image;

}

public?void?setImage(File?image)?{

this.image?=?image;

}

public?String?getImageFileName()?{

return?imageFileName;

}

public?void?setImageFileName(String?imageFileName)?{

this.imageFileName?=?imageFileName;

}

public?String?getImageContentType()?{

return?imageContentType;

}

public?void?setImageContentType(String?imageContentType)?{

this.imageContentType?=?imageContentType;

}

public?String?execute()?{

if?(image?!=?null)?{

System.out.println("file?name?is:"?+?this.imageFileName);

System.out.println("file?content?type?is:"?+?this.imageContentType);

System.out.println("file?length?is:"?+?this.image.length());

try?{

this.imageInputStream?=?new?FileInputStream?(image);

}?catch?(FileNotFoundException?e)?{

e.printStackTrace();

}

}

return?SUCCESS;

}

}

配置文件為，紅色為變化部分：

[html]?view plain?copy

action?name="imageUpload"?class="com.jpleasure.ImageUploadAction"

result?name="success"?type="stream"

param?name="contentType"image/pjpeg/param

param?name="inputName"imageInputStream/param

param?name="contentDisposition"attachment;filename="image.jpg"/param

param?name="bufferSize"1024/param

/result

/action

ContentType表示下載文件的類型。

InputName表示Action類中用來下載文件的字段的名字。

ContentDisposition用來控制文件下載的一些信息，包括是否打開另存對話框，下載文件名等。

BufferSize表示文件下載時使用的緩沖區(qū)的大小。

實際項目開發(fā)的考慮：

控制上傳文件的類型和最大允許上傳文件的size

使用File Upload Intercepter的參數(shù)可盈控制上傳文件的類型和最大允許上傳文件的size。例如：

[html]?view plain?copy

struts

package?name="myPackage"?extends="struts-default"

interceptor-ref?name="fileUpload"

param?name="maximumSize"2MB/param

param?name="allowedTypes"text/html,image/jpeg/param

/interceptor-ref

interceptor-ref?name="basicStack"/

action?name="imageUpload"?class="com.jpleasure.ImageUploadAction"

result?name="success"?type="stream"

param?name="contentType"image/pjpeg/param

param?name="inputName"imageInputStream/param

param?name="contentDisposition"

attachment;filename="image.jpg"

/param

param?name="bufferSize"1024/param

/result

/action

/package

/struts

上述表示允許上傳jpeg和html類型的文件，且最大文件上傳size為2MB

顯示錯誤信息：

可以使用如下key表示的message來顯示文件上傳出錯的提示信息：

消息Key ? ?說明 ?

struts.messages.error.uploading ? ?文件無法正常上傳時的公共錯誤 ?

struts.messages.error.file.too.large ? ?文件大小超過最大允許size時的錯誤提示 ?

struts.messages.error.content.type.not.allowed ? ?文件類型不在上傳文件允許類型中的錯誤提示 ?

java實現(xiàn)ftp斷點續(xù)傳問題

//嘗試移動文件內(nèi)讀取指針,實現(xiàn)斷點續(xù)傳

result

=

uploadFile(remoteFileName,

f,

ftpClient,

remoteSize);

//如果斷點續(xù)傳沒有成功，則刪除服務(wù)器上文件，重新上傳

if(result

==

UploadStatus.Upload_From_Break_Failed){

if(!ftpClient.deleteFile(remoteFileName)){

return

UploadStatus.Delete_Remote_Faild;

}

result

=

uploadFile(remoteFileName,

f,

ftpClient,

0);

}

關(guān)于JAVA斷點續(xù)傳

024字節(jié)）。第一次B接收了512字節(jié)，那么第二次連接A就應該從513字節(jié)開始傳輸。

也就是說，在第二次傳輸時，B要提供“我要從513字節(jié)開始傳送文件F”的信息，然后A使用FileInputStream構(gòu)建輸入流讀取本地文件，使用skip(512)方法跳過文件F的前512字節(jié)再傳送文件，之后B將數(shù)據(jù)追加（append）到先前接收的文件末尾即可。

進一步考慮，如果要實現(xiàn)多線程傳送，即分塊傳輸，也同樣的道理。假如B要求分作兩塊同時傳輸，那么A啟動兩個線程，一個從513字節(jié)讀到768字節(jié)（工256字節(jié)），第二個線程從769字節(jié)到1024字節(jié)即可。

如果你要從網(wǎng)絡(luò)上下載文件，就是說A方不是你實現(xiàn)的，那么你要先確認A方支不支持斷電續(xù)傳功能（HTTP1.1），然后你查閱下HTTP1.1協(xié)議，在HTTP1.1版本里，可以通過設(shè)置請求包頭某個字段的信息（使用URLConnection創(chuàng)建連接并使用setRequestProperty(String key, String value) 方法設(shè)置）從而精確讀取文件的某一段數(shù)據(jù)的。注意，基于HTTP斷點續(xù)傳的關(guān)鍵是1.1版本，1.0版本是不支持的。

補充：

嗯，查到了，是設(shè)置range屬性，即setRequestProperty("range", "bytes=513-1024").你可以使用迅雷下載某個文件，然后從”線程信息“中就可以看到這個http1.1斷點續(xù)傳的所有行為信息了。

Java Socket如何實現(xiàn)文件的斷點續(xù)傳，有代碼更好

1package com.tangshun.;

2

3import java.io.File;

4import java.io.IOException;

5import java.io.InputStream;

6import java.io.RandomAccessFile;

7import java.net.HttpURLConnection;

8import java.net.MalformedURLException;

9import java.net.URL;

10

11//斷點續(xù)傳

12public class DownLoad {

13

14 public static void down(String URL, long nPos, String savePathAndFile) {

15 try {

16 URL url = new URL(URL);

17 HttpURLConnection httpConnection = (HttpURLConnection) url

18 .openConnection();

19 // 設(shè)置User-Agent

20 httpConnection.setRequestProperty("User-Agent", "NetFox");

21 // 設(shè)置斷點續(xù)傳的開始位置

22 httpConnection.setRequestProperty("RANGE", "bytes=" + nPos);

23 // 獲得輸入流

24 InputStream input = httpConnection.getInputStream();

25 RandomAccessFile oSavedFile = new RandomAccessFile(savePathAndFile,

26 "rw");

27 // 定位文件指針到nPos位置

28 oSavedFile.seek(nPos);

29 byte[] b = new byte[1024];

30 int nRead;

31 // 從輸入流中讀入字節(jié)流，然后寫到文件中

32 while ((nRead = input.read(b, 0, 1024)) 0) {

33 (oSavedFile).write(b, 0, nRead);

34 }

35 httpConnection.disconnect();

36 } catch (MalformedURLException e) {

37 e.printStackTrace();

38 } catch (IOException e) {

39 e.printStackTrace();

40 }

41 }

42

43 public static long getRemoteFileSize(String url) {

44 long size = 0;

45 try {

46 HttpURLConnection conn = (HttpURLConnection) (new URL(url))

47 .openConnection();

48 size = conn.getContentLength();

49 conn.disconnect();

50 } catch (Exception e) {

51 e.printStackTrace();

52 }

53 return size;

54 }

55

56public static void main(String[] args) {

57 String url = " ";

58 String savePath = "F:\\";

59 String fileName = url.substring(url.lastIndexOf("/"));

60 String fileNam=fileName;

61 HttpURLConnection conn = null;

62 try {

63 conn = (HttpURLConnection) (new URL(url)).openConnection();

64 } catch (Exception e) {

65 e.printStackTrace();

66 }

67 File file = new File(savePath + fileName);

68 // 獲得遠程文件大小

69 long remoteFileSize = getRemoteFileSize(url);

70 System.out.println("遠程文件大小="+remoteFileSize);

71 int i = 0;

72 if (file.exists()) {

73 // 先看看是否是完整的，完整，換名字，跳出循環(huán)，不完整，繼續(xù)下載

74 long localFileSize = file.length();

75 System.out.println("已有文件大小為:"+localFileSize);

76

77 if (localFileSize remoteFileSize) {

78 System.out.println("文件續(xù)傳");

79 down(url, localFileSize, savePath + fileName);

80 }else{

81 System.out.println("文件存在，重新下載");

82 do{

83 i++;

84 fileName = fileNam.substring(0, fileNam.indexOf(".")) + "(" + i

85 + ")" + fileNam.substring(fileNam.indexOf("."));

86

87 file = new File(savePath + fileName);

88 }while(file.exists());

89 try {

90 file.createNewFile();

91 } catch (IOException e) {

92 e.printStackTrace();

93 }

94 down(url, 0, savePath + fileName);

95 }

96 // 下面表示文件存在，改名字

97

98 } else {

99 try {

100 file.createNewFile();

101 System.out.println("下載中");

102 down(url, 0, savePath + fileName);

103 } catch (IOException e) {

104 e.printStackTrace();

105 }

106 }

107 }}

108

如何用Java實現(xiàn)HTTP斷點續(xù)傳功能

斷點設(shè)置方法，當有臨時文件時，直接在臨時文件中讀取上次下載中斷時的斷點位置。沒有臨時文件，即第一次下載時，重新設(shè)置斷點。 rantmpfile.seek()跳轉(zhuǎn)到一個位置的目的是為了讓各個斷點存儲的位置盡量分開。