http断点续传简单实现（java)

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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)); |vEfE{
} paMw88*u
for(int i=0;i<nEndPos.length-1;i++) *%8,G'"r?
{ %tQIKjsVaY
nEndPos = nStartPos[i+1]; Mc@p~5!M
} -4GSGR'L&y
nEndPos[nEndPos.length-1] = nFileLength; |,}QhR
} ]G|@F :
} _L# Tp
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r>osa3N'
//启动子线程 <_42h|-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q^0K8>G^
for(int i=0;i<nStartPos.length;i++) c}rRNS$F
{ ;{HxY98Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mP:mzmUw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5HOhk"
nStartPos,nEndPos,i); ;5 IS58L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X>*zA?:
fileSplitterFetch.start(); G.<9K9K
} C'zMOR6c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tx5@r;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gs0,-)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :%!SzI?
nEndPos = " + nFileLength); Txp~&a03
// fileSplitterFetch[nPos.length-1].start(); _VY]
%/S BJ
)Dqv&^
//等待子线程结束 3c-ve$8u~
//int count = 0; I94;1(Cs%
//是否结束while循环 F}.Af=<Q
boolean breakWhile = false; 39k P)cD
nz>A\H
$dwv1@M2
while(!bStop) %iJ6;V4
{ r-[z!S
write_nPos(); pCpj#+|_)
Utility.sleep(500); aIqNNR
breakWhile = true; dIM:U:c
7&HP2r
HjV^6oP
for(int i=0;i<nStartPos.length;i++) 1f}S:Z
{ jp[QA\
if(!fileSplitterFetch.bDownOver) tP3H7Yl!g
{ ?(g kkYI
breakWhile = false; 4&`66\p;
break; I~q}M!v~
} %t<Y6*g
} <v5toyA
if(breakWhile) EH,uX{`e
break; /~AwX8X
(& ~`!]
<GoE2a4Va
//count++; n.7 $*9)#
//if(count>4) QjQJ "
// siteStop(); sPd5f2'
} gHox{*hb[
mZq*o<kTA
=8tduB
System.err.println("文件下载结束！"); W^yF5
} *DG*&Me
catch(Exception e){e.printStackTrace ();} =}Cb?C[;
} wv?`3:co
dC.uK^FuJ
9&2kuLp?P
//获得文件长度 <(^-o4Cl
public long getFileSize() xRaYm
{ WP}__1!%u
int nFileLength = -1; 4Y-9W2s
try{ o+aB[+
URL url = new URL(siteInfoBean.getSSiteURL()); qrt+{5/t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H;$w^Tr
httpConnection.setRequestProperty("User-Agent","NetFox"); 5[Q44$a{
B}?/oZW4
&/7GhZRt
int responseCode=httpConnection.getResponseCode(); k+s<;{
if(responseCode>=400) Mq*Sp UR
{ !N)oi$T%
processErrorCode(responseCode); Qh{=Z^r
return -2; //-2 represent access is error gu"Agct4
} VvoJ85
aC%0jJ<eo
2b3*zB*@V
String sHeader; *nH?o* #
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|d,1mmv@K
for(int i=1;;i++) g[eI-J+F
{ y"){?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (:hPT-1
//Utility.log(in.readLine()); Gt 2rJ<>
sHeader=httpConnection.getHeaderFieldKey(i); }. ,xhF[
if(sHeader!=null) 3w^q0/GD
{ i\`[0dfY
if(sHeader.equals("Content-Length")) O %)+ w
{ @&2T0UB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bBDgyFSI<
break; *1elUI2Rg
} &Nec(q<
} *Qyw _Q
else }Y-f+qX*
break; V;)'FJ)]
} AS8T!
} 40:YJ_n
catch(IOException e){e.printStackTrace ();} |Yk23\!
catch(Exception e){e.printStackTrace ();} }"3L>%Q5
\x|(`;{
2 3>lE}^G
Utility.log(nFileLength); 778L[wYe
JBg",2w |C
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return nFileLength; 6}|/~n
} x9@%L{*
Omh(UHZBB
u2!8'-Ai
//保存下载信息（文件指针位置） 2{&|%1Jg
private void write_nPos() @gTpiV2
{ 7OW;omT`
try{ Oj<2_u
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~ae68&L6
output.writeInt(nStartPos.length); ){gOb
for(int i=0;i<nStartPos.length;i++) vqL{~tR
{ 2|Tt3/Rn
// output.writeLong(nPos); w*bVBuXs
output.writeLong(fileSplitterFetch.nStartPos); Y&gfe8%5N
output.writeLong(fileSplitterFetch.nEndPos); KAUYE^
} 2RM1-j ($
output.close(); %DRDe
} H|,{^b@9
catch(IOException e){e.printStackTrace ();} {5_*f)$[H
catch(Exception e){e.printStackTrace ();} e348^S&rG
} 40@KL$B=
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$p9XXZ"*
//读取保存的下载信息（文件指针位置） 9jvg[H
private void read_nPos() SX FF
{ Ufo-AeQo
try{ O|gb{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iPkG=*Ip(%
int nCount = input.readInt(); W<9GwMU
nStartPos = new long[nCount]; X;}_[=-
nEndPos = new long[nCount]; fA+M/}=
for(int i=0;i<nStartPos.length;i++) c85B-/
{ c%B=TAs5c
nStartPos = input.readLong(); 4CN8>J'-
nEndPos = input.readLong(); |-e=P9,
} IA+>dr
input.close(); se)I2T{J
} QZwRg&d<o
catch(IOException e){e.printStackTrace ();} C-2n2OM.
catch(Exception e){e.printStackTrace ();} -(1e!5_-@
} b<[eBXe
} g
0 TS:o/{(a
private void processErrorCode(int nErrorCode) t@4vEKw?.X
{ )}6:Ke)
System.err.println("Error Code : " + nErrorCode); zZE?G:isR
} _wX'u,HrC
rre;HJGEL
| _S9U|
//停止文件下载 ,p 'M@[
public void siteStop() O&X-)g=
{ 95(VY)_6#A
bStop = true; {+`ep\.$&
for(int i=0;i<nStartPos.length;i++) S[ 2`7'XV
fileSplitterFetch.splitterStop(); Sa<R8X'J
dm.3.xXq
s%/0WW0y^
} 8zY)0
} ( NiuAy
//负责部分文件的抓取 rhUZ9Fdv
**FileSplitterFetch.java }Rf } iG
*/ jEI!t^#
package NetFox; 1yKf=LZ^
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[hiOFmMJZ-
import java.io.*; :Z+(H+lyZ
import java.net.*; ^.<IT"
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public class FileSplitterFetch extends Thread { N4D_ 43jz
i?|SC=
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String sURL; //File URL Lh. L~M1X
long nStartPos; //File Snippet Start Position \(A>~D8Fo
long nEndPos; //File Snippet End Position ()SG
int nThreadID; //Thread's ID , n EeI&
boolean bDownOver = false; //Downing is over ;aFQP:l/
boolean bStop = false; //Stop identical pFG~XW
FileAccessI fileAccessI = null; //File Access interface *]H ./a:1
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'uPqe.#?
{ lOEbh
this.sURL = sURL; mqE&phF,
this.nStartPos = nStart; ; aMMIp
this.nEndPos = nEnd; cq!>B{
nThreadID = id; `"D7XC0x
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c(eu[vj:
} #6YNgJNk
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2h/`RefHJ
public void run() _x>u"w
{ 3*'!,gK~[
while(nStartPos < nEndPos && !bStop) FB</~ g
{ +V0uHpm
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Uh7kB`2
try{ %iX+"
URL url = new URL(sURL); sDwSEg>#B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bZKK'd$I
httpConnection.setRequestProperty("User-Agent","NetFox"); Jl4zj>8~
String sProperty = "bytes="+nStartPos+"-"; }2{%V^D)r
httpConnection.setRequestProperty("RANGE",sProperty); 1ITa6vjS
Utility.log(sProperty); yqAw7GaBN
fa6L+wt4O
%RJW@~!
InputStream input = httpConnection.getInputStream(); ;1o"Oij
//logResponseHead(httpConnection); cy? EX~s4
%f^TZ,q$
|M+ !O93
byte[] b = new byte[1024]; .E@yB`AR
int nRead; iaR'):TD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \K>6-0r|
{ i|2Q}$3t2
nStartPos += fileAccessI.write(b,0,nRead); _E?(cWC
//if(nThreadID == 1) 9BF#R<}h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .m4K ]^m
} 0Uybh.dC
udw5A*Ls
^6obxwVG
Utility.log("Thread " + nThreadID + " is over!"); j:fL_1m
bDownOver = true; bhFzu[B
//nPos = fileAccessI.write (b,0,nRead); PDtaL
} gB&'MA!
catch(Exception e){e.printStackTrace ();} > ^D10Nf*
} 2avSsN{^
} B!9<c9/ P]
*}LYMrP
TMq\}k-I5
//打印回应的头信息 I*'QD)
public void logResponseHead(HttpURLConnection con) "y62Wo6m)
{ rs<UWk<q
for(int i=1;;i++) gx#TRp}-
{ O'_D*?
String header=con.getHeaderFieldKey(i); 3F<My+J
if(header!=null) )5p0fw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cnQ( G$kh
Utility.log(header+" : "+con.getHeaderField(header)); tEZ@v(D
else Azu$F5G!n
break; #W*5=Cf
} vJK0>":G
} yn`H}@`k
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\V}?K0#bt
public void splitterStop() 8NA2C.gOZ
{ ;CFI*Wfp
bStop = true; h=?#D0
} P!1y@R>Ln
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} vz/.*u
ub7|'+5
jDOB(fE
/* 4E<iIA\x
**FileAccess.java RCgZ GP
*//文件访问(定位，写) t4~Bn<=
package NetFox; "0pu_
import java.io.*; eG=Hyc
4f'1g1@$
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public class FileAccessI implements Serializable{ E&#cU}ErN
(TgLCT[@T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `ZC_F! E
RandomAccessFile oSavedFile; p0>W}+8fF
long nPos; dXg.[|S*
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|W:xbtPNy
public FileAccessI() throws IOException ko2?q
{ MV'q_{J
this("",0); 7vF+Di(B
} F4`ud;1H
lhZXq!2p
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public FileAccessI(String sName,long nPos) throws IOException "**Tw'
{ =c8xg/
oSavedFile = new RandomAccessFile(sName,"rw"); Psm5J80}n
this.nPos = nPos; >cpT_M&C,
oSavedFile.seek(nPos); iGlg@
} +" |?P
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"}fJ 2G3
public synchronized int write(byte[] b,int nStart,int nLen) td@I ;d2
{ Y=6569U2
int n = -1; sVWOh|O[W
try{ g3B%}!|
oSavedFile.write(b,nStart,nLen); |zd+ \o
n = nLen; ( y0
} =#L\fe)q)
catch(IOException e) vLCyT=OB`
{ 57@6O-t-
e.printStackTrace (); g6aIS^mU
} 2 8>
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return n; [/E|n[Bx
} 5y^I~"_i
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kZ5;Fe\*
} aNUU' [
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q8 &\;GK|
/* o{]2W `0r
**SiteInfoBean.java $Iz*W]B!
*/ '<=77yDg
package NetFox; h8XoF1wuw
TF_wT28AU2
yjE$o?A
public class SiteInfoBean { pf% yEz
{HO,d{{
3R>"X c
private String sSiteURL; //Site's URL OV2/?
private String sFilePath; //Saved File's Path WQiIS0BJ *
private String sFileName; //Saved File's Name \JLea$TM:
private int nSplitter; //Count of Splited Downloading File ~v>3lEGn*
@b&_xT
@6"+x
public SiteInfoBean() M!R=&a=Z
{//nSplitter的缺省值为5 n:"0mWnL$y
//default value of nSplitter is 5 joA>-k04
this("","","",5); 3D}Pa
} _s18^7
imc1rY!~'
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J7pF*2
{ H-iCaXT
sSiteURL= sURL; \RS0mb
sFilePath = sPath; W"!{f
sFileName = sName; 1<G,0Lt
this.nSplitter = nSpiltter; S'(IG m4
,K15KN.'
k 1lK`p
} O03N$Jq A
P"{yV?CNg
:sX4hZK=G
public String getSSiteURL() zDf96eK
{ Q_6v3no1
return sSiteURL; m1D,#=C,_
} PDpuHHB
e}NB ,o
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public void setSSiteURL(String value) kq*IC&y
{ r ?<?0j
sSiteURL = value; GdM|?u&s"
} cwE?+vB
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"^)$MAZ
public String getSFilePath() W0S\g#
{ " 1h~P,
return sFilePath; Am<){&XT ]
} z s\N)LyM
'soll[J
8iPA^b|sz{
public void setSFilePath(String value) =)%~QK{Y
{ `j4OKZ
sFilePath = value; E~S~Ld%
} YRu/KUT$ 7
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v2ab84 C*
public String getSFileName() WtlLqD!_D
{ To;r#h
return sFileName; r.' cjUs
} F!RP *
# ';b>J
bwK1XlfD.s
public void setSFileName(String value) cS>xT cj
{ 8aY}b($*ZI
sFileName = value; n{!=gR.v.
} !]MGIh#u
=.IAd<C
au+a7~0~
public int getNSplitter() 'DUYf5nF
{ ahR-^^'$
return nSplitter; -+Z&O?pSH
} #;\tgUQ
t?FPmbjv
#Wt1Ph_;
public void setNSplitter(int nCount) RaA7 U
{ <%"CQT6g%
nSplitter = nCount; Ku8qn\2"
} T9AFL;1
} `L"l{^cH
t x1(6V&l;
mW#p&{
/* GC@U['
**Utility.java ~g&Gi)je
*/ ?V})2wwP
package NetFox; 9j1 tcT
N lB%Qu
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public class Utility { 5xc-MkIRL
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?r R, h{~
public Utility() AAK}t6
{ nn/_>%Y
&Fl*,
\)BDl
} 88+J(^y>
L)_L#]Yy
//线程睡眠 `BY&&Bv#?
public static void sleep(int nSecond) =)2!qoE
{ y_Nn%(j
try{ PxgLt2dXa
Thread.sleep(nSecond); lR3JyYY{X
} Z"a]AsG/Q#
catch(Exception e) G `JXi/#`
{ xkkW?[&
e.printStackTrace (); G 4C 7
} !J+< M~o}
} QfsTUAfR
#zw 'H9l
//日志 }P"JP[#E\
public static void log(String sMsg) VK?c='zg
{ \B D'"
System.err.println(sMsg); 30$Q5]T
} .{LJ
fm'Qifq^
Ov9kD0S
public static void log(int sMsg) hh"=|c
{ ,a?$F1Z-
System.err.println(sMsg); .+hM1OF`x
} 7I<];j
} j%OnLTZ
*27*&&=)H
&l NHNu[
/* +BE_K_56
**TestMethod.java >L>t$1hXM
*/ 7nL3+Pq
package NetFox; jaImO
tL~?)2uEN
@}@J$ g
public class TestMethod { f")*I
Um9]X@z
?$LKn2C
public TestMethod() b_T?jCyW
{ ///xx/weblogic60b2_win.exe 4`#3p@-
try{ DEkFmmw
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1f^4J~{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |KxFiH
SiteFileFetch fileFetch = new SiteFileFetch(bean); {JlW1;Jc7
fileFetch.start(); pC'GKk 8
} D#n^U `\if
catch(Exception e){e.printStackTrace ();} ;n,@[v
2v6QUf
px1{=~V/
} }$ZcC_
idr,s\$>
*n=NBkq%/!
public static void main(String[] args) Ll !J!{
{ l[q%1-N
new TestMethod(); v8xNtUxN
} tj_+0J$sw:
} d8? }69:h
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