http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); G9Tix\SpF
} cyg>hX{U
for(int i=0;i<nEndPos.length-1;i++) DU8LU*q'
{ Uiw7Y\Im|
nEndPos = nStartPos[i+1]; U{(07GNm#
} /GGu` f
nEndPos[nEndPos.length-1] = nFileLength; 8ZfIh
} V}+;bbUc-
} =lQ[%&
?Nql7F4
|3ETF|)?
//启动子线程 ZRGZ'+hw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [zEP|
for(int i=0;i<nStartPos.length;i++) ?GU!ke p
{ "\?G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), );H[lKy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~W{h-z%q
nStartPos,nEndPos,i); ;tiUOixJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P@`"MNS
fileSplitterFetch.start(); ',Pk>f]AB-
} ^I?y\:.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q.{/{9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g>P9hIl
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4{t$M}?N
nEndPos = " + nFileLength); *Bsmn!_cB{
// fileSplitterFetch[nPos.length-1].start(); e/jM+%
vK`h;
,8nZzVo
//等待子线程结束 9Ib(x0_
//int count = 0; FH`&C*/F0Y
//是否结束while循环 m-92G8'
boolean breakWhile = false; q|l|mO
UyKG$6F?3
j)6B^!
while(!bStop) [:@?,?V\N
{ $IZZ`Z]B
write_nPos(); 6 <S&~q
Utility.sleep(500); [;YBX]t
breakWhile = true; >I~z7JS
^QR'yt3e
;o459L>sW
for(int i=0;i<nStartPos.length;i++) w1(06A}/
{ v};qMceJ
if(!fileSplitterFetch.bDownOver) X$Vz
{ Go7hDmu
breakWhile = false; 5?0gC&WfN
break; aZGDtzNG5h
} )'`AX\
} f<p4Pkv
if(breakWhile) <>Ddxmw
break; `h5eej&s(
L#q9_-(#
x`vs-Y:P
//count++; :";D.{||
//if(count>4) !H=k7s
// siteStop(); .|`=mx
} g~:(EO(w
C-^%g[#
Z1&GtM
System.err.println("文件下载结束！"); [Fj+p4*N
} M8j(1&(:
catch(Exception e){e.printStackTrace ();} zTT
} AeCG2!8^0
B00wcYM<1r
^|i\d\
//获得文件长度 h21(K}
public long getFileSize() kDl4t]j
{ Zbh]SF{3F
int nFileLength = -1; #_\MD,(
try{ *u;">H*BW
URL url = new URL(siteInfoBean.getSSiteURL()); :_,]?n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "u8o?8+q~
httpConnection.setRequestProperty("User-Agent","NetFox"); G,|]a#w&v.
EZumJ."
;=\5$J9
int responseCode=httpConnection.getResponseCode(); \"`>-v"h
if(responseCode>=400) UAXF64w{
{ `pd
processErrorCode(responseCode); GKujDx+h
return -2; //-2 represent access is error |iUfM3
} n!eqzr{
p6y0W`U
&DQ4=/Z
String sHeader; ka)LK@p6
eGe[sv"k
6#x)W
for(int i=1;;i++) K[>@'P}y
{ UtBlP+bE?y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lH@E%
//Utility.log(in.readLine()); }A)36
sHeader=httpConnection.getHeaderFieldKey(i); 5ZyBP~
if(sHeader!=null) Zjic"E1
{ UQ.D!q
if(sHeader.equals("Content-Length")) nHA`B.:B
{ :e<`U~8m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Tb0;Mbr
break; PUjoi@]
} !Xx<~lIC
} hp]ng!I{\u
else +fP/|A8P
break; 'W?v.W &
} JQ/t, v$G
} [[0bhmG)
catch(IOException e){e.printStackTrace ();} ZG/8Ds
catch(Exception e){e.printStackTrace ();} ]%<Q:+38
&e]]F#
Ce5w0&VlS
Utility.log(nFileLength); hi3sOK*r;<
O? Gl4_y
<[y$D=n
return nFileLength; `f6)Q`n
} Rw/JPC"
f*T)*R_
`zzKD2y
//保存下载信息（文件指针位置） =2nn "YVP
private void write_nPos() }6CXJ+-UR
{ N;x<| %peL
try{ LE<u&9I\
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~6-"i0k
output.writeInt(nStartPos.length); si^4<$Nr%j
for(int i=0;i<nStartPos.length;i++) Z`oaaO
{ Od!F: <
// output.writeLong(nPos); eN]>l
output.writeLong(fileSplitterFetch.nStartPos); )zW%\s*'
output.writeLong(fileSplitterFetch.nEndPos); n-hvh-ZO
} ]/o12pI
output.close(); Jny)uo8
} Q$fRi[/L
catch(IOException e){e.printStackTrace ();} *TM;trfz
catch(Exception e){e.printStackTrace ();} ksu}+i,a
} '6o`^u>
hEv=T'*,K)
CP]S-o}yd
//读取保存的下载信息（文件指针位置） o=-Vt,2{
private void read_nPos() b\?7?g
{ ljYpMv.>xG
try{ aVppOxA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -3G 4vRIo
int nCount = input.readInt(); 97(Xu=tX
nStartPos = new long[nCount]; ws>WA{]gq
nEndPos = new long[nCount]; BSfm?ku"!
for(int i=0;i<nStartPos.length;i++) tM^;?HL]
{ *gd?>P7\0
nStartPos = input.readLong(); <Qcex3
nEndPos = input.readLong(); )+n,5W
} QY~<~<d+G
input.close(); Xq,UV
} ePq13!FC/
catch(IOException e){e.printStackTrace ();} cebs.sF:
catch(Exception e){e.printStackTrace ();} gV"qV
} `dv}a-Q)c
/ojO>Y[<
Sa;<B:|
private void processErrorCode(int nErrorCode) t;.^K\S4
{ @K$VV^wp
System.err.println("Error Code : " + nErrorCode); %@lV-(5q
} Lj&1K~U
n5Nan
:DdBn.
//停止文件下载 GJ1;\:cQq
public void siteStop() d~{jEg
{ L$+d.=]
bStop = true; K\{b!Cfr^
for(int i=0;i<nStartPos.length;i++) <+AIt
fileSplitterFetch.splitterStop(); N5 SLF4R1
{W5ydHXy
bJQ5- *F
} AT B\^;n.
} Hp)X^O"
//负责部分文件的抓取 n7IL7?!o
**FileSplitterFetch.java [G{rHSK5tQ
*/ CM%|pB/z
package NetFox; r}/yi
;wij}y-6
2;r]gT~
import java.io.*; \{c,,th
import java.net.*; _tWJXv~;
nG"tO'J6
@+'c+
public class FileSplitterFetch extends Thread { k}-yOP{
:/C ?FHs9
;^R A!Nj
String sURL; //File URL .:}.b"%m
long nStartPos; //File Snippet Start Position #ZG3|#Q=L
long nEndPos; //File Snippet End Position };&HhBc!g
int nThreadID; //Thread's ID kOs(?=
boolean bDownOver = false; //Downing is over :tRf@bD#
boolean bStop = false; //Stop identical <^lJr82
FileAccessI fileAccessI = null; //File Access interface }3v'Cp0L
$ A-+E\vQ@
JDLTOLG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &w+;N5}3
{ t)-*.qZh
this.sURL = sURL; (k%GY< bP
this.nStartPos = nStart; W8w3~
this.nEndPos = nEnd; 01U *_\
nThreadID = id; bTZ>@~$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j?EskT6
} h ?uqLsRl
06 QU
5Z/yhF.{
public void run() 5]jx5!N
{ M]}l^m>L
while(nStartPos < nEndPos && !bStop) yiiyqL*E
{ vB[~pQ;Z
<,\ `Psa)N
W7H&R,
try{ P @zz"~f7
URL url = new URL(sURL); }10\K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,Pn-ZF
httpConnection.setRequestProperty("User-Agent","NetFox"); (2UW_l
String sProperty = "bytes="+nStartPos+"-"; z0#-)AeS
httpConnection.setRequestProperty("RANGE",sProperty); mDE'<c`b4
Utility.log(sProperty); "r u]?{v
/:bKqAz;M
e# t3u_
InputStream input = httpConnection.getInputStream(); {vs 4vS6
//logResponseHead(httpConnection); C\ tprnY
k!5m@'f
/\ytr%7,'
byte[] b = new byte[1024]; @.'z* |z
int nRead; =WC-Sj{I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !RS9%ES_?
{ rJ'/\Hh5P
nStartPos += fileAccessI.write(b,0,nRead); puOC60zI
//if(nThreadID == 1) K*~]fy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _@Y"$V]=Vt
} MR`:5e
1%%'6cWWu
WzjL-a(
Utility.log("Thread " + nThreadID + " is over!"); yQ9ZhdQS
bDownOver = true; Mtm/}I
//nPos = fileAccessI.write (b,0,nRead); pe9@N9_5
} d')-7C
catch(Exception e){e.printStackTrace ();} sONBQ9
} o/C(4q6d
} g& k58{e
$[g_=Z
!=3Rg-'d1
//打印回应的头信息 Guh%eR'Wt
public void logResponseHead(HttpURLConnection con) #/|75 4]]
{ ['z!{Ez
for(int i=1;;i++) n|Pr/ddL
{ ?>af'o:
String header=con.getHeaderFieldKey(i); &-M]xo^
if(header!=null) f|U0s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); baee?6
Utility.log(header+" : "+con.getHeaderField(header)); f;gZ|a
else b.s9p7:J
break; Ur^j$B}
} {Hl[C]25X
} UfO7+_2
<\" .L
%a];
public void splitterStop() H6gU?9%
{ n 6{2]&sd
bStop = true; MM?`voj~`p
} Y>BP?l
m 41t(i
'Hw4j:pS
} nBN&.+3t
@wp4|G
Gih[i\%Q
/* q]\X~ 9#
**FileAccess.java &-%X:~|:X
*//文件访问(定位，写) P}V=*g
package NetFox; k;I &.H
import java.io.*; EATu KLP\
3$VxRz)
MAqLIf<G
public class FileAccessI implements Serializable{ /-4$7qd
oE?QnH3R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3xNMPm
RandomAccessFile oSavedFile; Q$ri=uB;+
long nPos; >`'O7.R
1tB[_$s
BByCMY
public FileAccessI() throws IOException .R5y:O
{ 99=s4*xzM
this("",0); R^*K6Ad
} dRI^@n
-h#mn2U~3r
N j4IQ<OV
public FileAccessI(String sName,long nPos) throws IOException <YFY{VC(
{ ]3B%8
oSavedFile = new RandomAccessFile(sName,"rw"); 15{Y9!
this.nPos = nPos; GKiukX$'
oSavedFile.seek(nPos); v>A=2i*j
} 4 o(bxs"
Xf d*D
,e`'4H
public synchronized int write(byte[] b,int nStart,int nLen) ifK%6o6
{ ~]'pY
int n = -1; U7iuY~L
try{ I]nHbghcW
oSavedFile.write(b,nStart,nLen); ;n6b%,s
n = nLen; -x`G2i
} M+`Hg_#Q
catch(IOException e) xd-XWXc
{ 9}29&O
e.printStackTrace (); BVw Wj-,
} @kFu*"
~D[?$`x:
re &E{
return n; 1l8Etp&<
} 6rN(_Oi-
B[5r|d'
xJZ@DR,#
} X|DO~{-au
fNu'((J-
>dzsQ^Nj
/* E7zm{BX]
**SiteInfoBean.java Bi3+)k>u7
*/ Pw0Ci
package NetFox; ?=;qK{)37
^Q+i=y{W
zsXoBD\h
public class SiteInfoBean { C\ZkGX
!? 5U|
sZ&G%o
private String sSiteURL; //Site's URL %\$;(#h
private String sFilePath; //Saved File's Path 1w(JEqY3h:
private String sFileName; //Saved File's Name xI*#(!x"G
private int nSplitter; //Count of Splited Downloading File DI|:p!Nx
L,,*gK
]aryV?!6
public SiteInfoBean() nqVZqX@oE
{//nSplitter的缺省值为5 kcie}Be
//default value of nSplitter is 5 =*vMA#e
this("","","",5); `Y=WMNy
} *i{Y9f8
f.B>&%JRZ
6 sxffJt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^!8P<y
{ 9Z5D\yv?H
sSiteURL= sURL; ]iNEw9
sFilePath = sPath; -62'}%?A<C
sFileName = sName; E\nv~Y?SG
this.nSplitter = nSpiltter; X>YsQrK(ig
JwnQ0 e
t*<#<a
} I zbU)ud
eM7Bc4V
F}GPZ=T;
public String getSSiteURL() YC_5YY(k
{ !QI\Fz?
return sSiteURL; 8vSse
} YW@#91.
hwN?/5
`+:.L>5([
public void setSSiteURL(String value) !HeSOzN
{ ^u}L;`L
sSiteURL = value; 7R#+Le)
} _p-t<ytnh
jOpcV|2
9+s.w25R
public String getSFilePath() ml|W~-6l
{ >odbOi+X
return sFilePath; me6OPc;:!
} cRd0S*QN2
5 <wnva
mI*[>#q>
public void setSFilePath(String value) oh"O07
{ 65h @}9,U
sFilePath = value; {U<xdG
} ~=<}\a~
rNjn~c
ZQ^r`W9_+
public String getSFileName() C98]9
{ (/-hu[:
return sFileName; ae"]\a\&1o
} Ghl'nqPlm
'0y9MXRT
"<_0A f]
public void setSFileName(String value) iRg7*MQu
{ =[\s8XH,
sFileName = value; A1P K
} r:&`$8$
53-v|'9'
;zM*bWh9
public int getNSplitter() r<F hY
{ R8rfM?"W
return nSplitter; Ev7J+TmXM
} mWR4|1(
oI)GKA_Ng7
2aJS{[
public void setNSplitter(int nCount) p~noM/*2r
{ uZfnzd)c
nSplitter = nCount; +dA,P\
} P=3RLL<l
} W^3uEm&l!)
%sHF-n5P
E9?phD
/* r]3'74j:
**Utility.java JpsPNa
*/ O+}qQNe<
package NetFox; `wF8k{Pb
Mu'8;9_6
iyj+:t/
public class Utility { ?4H i-
it]E-^2>
D]c`B
public Utility() /Q~gU<
{ A,r*%&4~
vad12WrG<
yG Wnod'
} ` PYJ^I0
f2,jh}4
//线程睡眠 =K{\p`?
public static void sleep(int nSecond) cUTE$/#s
{ %QKZT=}
try{ #2r}?hP/m
Thread.sleep(nSecond); /'31w9
} +w=AJdc
catch(Exception e) ynA|}X
{ h3dsd
e.printStackTrace (); &WNf M+
} JaB<EL-9r2
} Gmf B
u,}{I}x_
//日志 Q{B}ef
public static void log(String sMsg) K&8dA0i2u2
{ 7^w >Rj
System.err.println(sMsg); nLV9<M Zm
} wdUBg*X8
l}$ U])an#
pp7$J2s+j
public static void log(int sMsg) ox+ 3U
{ hWH:wB
System.err.println(sMsg); )T;?^kho
} keB&Bjd&
} =XXZ?P
_/wV;h~R
pZtu&R%GU
/* SPp#f~%m
**TestMethod.java `'V4PUe
*/ meOMq1
package NetFox; q$aaA`E%
0_CN/5F
sg+uBCGB
public class TestMethod { -eX5z
i+gQE!
@xB*KyUW
public TestMethod() $V1;la!
{ ///xx/weblogic60b2_win.exe JA)] _H P
try{ 2 !'A:;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dDF .qXq.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o1<_fI
SiteFileFetch fileFetch = new SiteFileFetch(bean); `X3^fg
fileFetch.start(); `F/Tv 5@L
} }[M`uZ
catch(Exception e){e.printStackTrace ();} {#)0EzV6
nxr!`^Mne
ATR!7i\|
} }fKSqB]T-
=|9H
9'r:~O
public static void main(String[] args) R9B&dvG
{ +"1NC\<*
new TestMethod(); &gjF4~W]
} qbv#I;
} q`pP$i:
点击下载更多相关资料