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)); aaa#/OWQZ
} uN?O*h/(
for(int i=0;i<nEndPos.length-1;i++) :Jsz"vCg&s
{ VQW)qOR9
nEndPos = nStartPos[i+1]; VdN+~+A:
} T\b";+!W
nEndPos[nEndPos.length-1] = nFileLength; Al-%j- j@-
} *{p&Fy55
} JNA}EY^2I.
hvv>UC/
.of:#~
//启动子线程 ] l qFht
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <=GzK:4L
for(int i=0;i<nStartPos.length;i++) /{#_Um0.
{ tV}ajs
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (HX[bG`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q.hc%s2?
nStartPos,nEndPos,i); 0g*r!aa
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HDae_.
fileSplitterFetch.start(); 4Xb}I;rM
} uZ39Vx
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d_?Zr`:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YC,.Y{oY{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5Z>pa`_$2
nEndPos = " + nFileLength); HZQ3Ht3Vh
// fileSplitterFetch[nPos.length-1].start(); {p_vR/yN
< $?}^ 0R
-~GJ; Uw
//等待子线程结束 Tk|;5^#H
//int count = 0; +Gwe%p Q
//是否结束while循环 kG7,1teMk
boolean breakWhile = false; `0WA!(W
R(Pa Q
qYiK bzy
while(!bStop) 1AkHig,
{ `h{mj|~
write_nPos(); KJ{F,fr+v
Utility.sleep(500); WuQ<AS=
breakWhile = true; pj-HLuZR
o0+BQ&A)s*
i}{Q\#=#
for(int i=0;i<nStartPos.length;i++) yt#;3
{ G#n)|p
if(!fileSplitterFetch.bDownOver) Tq_X8X#p
{ K1{nxw!`
breakWhile = false; Gy7x?
break; |[7$) $
} p:>?
} iwx0V
if(breakWhile) U;dt-3?=.h
break; yzzre>F
3EX&.OL!
"X}F%:HL
//count++; wgP3&4cSUc
//if(count>4) T@.m^|~
// siteStop(); tSLl'XeN
} ~vZzKRVS
u,9U0ua@;
v7u}nx
System.err.println("文件下载结束！"); hg/&[/eodm
} e>9{36~jh
catch(Exception e){e.printStackTrace ();} 3Ty{8oUs^
} -#M~NbI,
NGZ>:
"/h"Xg>q
//获得文件长度 NJ!#0[@C
public long getFileSize() !fjU?_[S
{ MQMy Z:
int nFileLength = -1; h#;K9#x6
try{ i4Cb&h^
URL url = new URL(siteInfoBean.getSSiteURL()); _rh.z_a7w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BCB/cBE
httpConnection.setRequestProperty("User-Agent","NetFox"); <a}|G1 h
zd]L9 _
ghR]$SG
int responseCode=httpConnection.getResponseCode(); fB}5,22
if(responseCode>=400) R*#Q=_
{ ;//qjo
processErrorCode(responseCode); W/X;|m`
return -2; //-2 represent access is error U>jk`?zW
} 3;gtuqwD$
[zd-=.:+M[
/s_$CSiB
String sHeader; )F2tV ]k\
`3s-\>
IoX9yGq
for(int i=1;;i++) BV:,bS
{ >{=RQgGy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YAG3PWmD
//Utility.log(in.readLine()); Z6ex<[`I
sHeader=httpConnection.getHeaderFieldKey(i); f TtMmz
if(sHeader!=null) [cs8/Q8+
{ WX"M_=lc-@
if(sHeader.equals("Content-Length")) `W S
{ /Loe y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2xj`cFT
break; 64s;6=
} H<?yG->
} bx6}zkf&
else jd'R2e
break; GQNiBsV
} }TLC b/+
} e@VRdhb
catch(IOException e){e.printStackTrace ();} bJ}+<##
catch(Exception e){e.printStackTrace ();} U<gw<[>f
WR1,J0UU6
}PuO$ L
Utility.log(nFileLength); OaWq8MIZ-
ir?9{t/()
:UciFIa
return nFileLength; ["/x~\c'N
} ,FO|'l
"G(/MT^C
=?aB@&
//保存下载信息（文件指针位置） __npX_4%S
private void write_nPos() #O ]IXo(5z
{ (k45k/PAP
try{ -6>rR{z
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2F{IDcJI\
output.writeInt(nStartPos.length); .[A S
for(int i=0;i<nStartPos.length;i++) =0Sa
{ Z2}b1#U?
// output.writeLong(nPos); r2w7lf66!
output.writeLong(fileSplitterFetch.nStartPos); [%Xfl7;Wh
output.writeLong(fileSplitterFetch.nEndPos); 9$i`B>C~
} $ 7!GA9Bn
output.close(); 5}ah%
} v$Z1Lh
catch(IOException e){e.printStackTrace ();} cxdM!L; `
catch(Exception e){e.printStackTrace ();} C3gz)!3
} _=#mmZkq
| w -W=v
H0 t1& :
//读取保存的下载信息（文件指针位置） M?lr#}d
private void read_nPos() B\yid@e
{ mD3#$E!A1
try{ [8#l~ |U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ".IhV<R
int nCount = input.readInt(); .}s a2-
nStartPos = new long[nCount]; WH*&MIjAr/
nEndPos = new long[nCount]; SF7 Scd
for(int i=0;i<nStartPos.length;i++) v<W++X7z
{ \PJ89u0
nStartPos = input.readLong(); iL<O|'be
nEndPos = input.readLong(); I^=M>_s4
} "?-s Qn
input.close(); *uR'eXW
} cB^lSmu5
catch(IOException e){e.printStackTrace ();} WkE;tC*
catch(Exception e){e.printStackTrace ();} l:HuG!
} ^<-SW]x
Vo()J4L
6WZp&pO
private void processErrorCode(int nErrorCode) <D}k@M Z
{ ww,'n{_
System.err.println("Error Code : " + nErrorCode); C/G[B?:h
} "H8N,eb2
7dZ!GX?\y
\)*qW[C$a
//停止文件下载 H#K|SSqY?
public void siteStop() ?*=Jq
{ tTal<4
bStop = true; (B5G?cB9
for(int i=0;i<nStartPos.length;i++) L\I/2aiE
fileSplitterFetch.splitterStop(); ~MF. M8
1)y}.y5S
4<|]k?@
} 2z:9^a/]Na
} qS>el3G
//负责部分文件的抓取 \&fK8H1
**FileSplitterFetch.java R}FN6cH
*/ G].Z| Z9
package NetFox; e6Y0G,K
]h6<o*
tEl_A"^e
import java.io.*; {1[8,Ho
import java.net.*; %Ok.XBS)
vHmn)d1pl
%0QYkHdFR`
public class FileSplitterFetch extends Thread { IV76#jL
2cL<`
\Uiw: ,
String sURL; //File URL +FI]0r
long nStartPos; //File Snippet Start Position t"Rn#V\c."
long nEndPos; //File Snippet End Position (#~063N,#
int nThreadID; //Thread's ID %"D-1&%zY
boolean bDownOver = false; //Downing is over K9c:K/H
boolean bStop = false; //Stop identical eo!{rs@f
FileAccessI fileAccessI = null; //File Access interface umk[\}Ip+P
PYGHN T
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~7|z2L
{ &LE/hA
this.sURL = sURL; wbTw\b=
this.nStartPos = nStart; 7o3f5"z
this.nEndPos = nEnd; *"wsMO
nThreadID = id; NeH^g0Q2,g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Jc*A\-qC.
} LvS`
t$b`Am
S:wmm}XQ
public void run() q-'zZ#
{ 8l6R.l
while(nStartPos < nEndPos && !bStop) j1)w1WY0@
{ :7gIm|2"]
{8eNQ-4I
sqhM[u k
try{ }QK-@T@4<
URL url = new URL(sURL); $P$OWp?b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B4%W,F:@
httpConnection.setRequestProperty("User-Agent","NetFox"); h8Gp>b
String sProperty = "bytes="+nStartPos+"-"; "\30YO>\
httpConnection.setRequestProperty("RANGE",sProperty); [1Rs~T"
Utility.log(sProperty); :0/I2:
*`[LsG]ZF
~~&M&Fe
InputStream input = httpConnection.getInputStream(); &0'BCT
//logResponseHead(httpConnection); 0=NB[eG
c(:GsoO
d4/ZOj+%
byte[] b = new byte[1024]; #-{4F?DA]y
int nRead; \7RP6o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'Q# KjY
{ o4xZaF4+
nStartPos += fileAccessI.write(b,0,nRead); ral0@\T
//if(nThreadID == 1) \O[Cae:^?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n,`&f~tap
} `3~w#?+=*
|2Q;SaI^\
rLVS#M#&e>
Utility.log("Thread " + nThreadID + " is over!"); q*>`HTPcU
bDownOver = true; O3S_P]{*ny
//nPos = fileAccessI.write (b,0,nRead); mU;TB%#)
} yA~W|q(/V
catch(Exception e){e.printStackTrace ();} N7XRk=J
} Y:O%xtGi
} g94NU X
Y`%:hvy~
L49`=p<
//打印回应的头信息 _95V"h
public void logResponseHead(HttpURLConnection con) /IODRso/!
{ ^XV$J-
for(int i=1;;i++) ^j@,N&W:lG
{ <S<(wFE@4
String header=con.getHeaderFieldKey(i); @#nB]qV:e
if(header!=null) h/d&P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bx1'
Utility.log(header+" : "+con.getHeaderField(header)); o}<}zTU
else S>nM&758
break; -YD6
} VK8 5A
} e tY9Pq
WSL_Dc
tR1 kn&w
public void splitterStop() N]gdS]pP2{
{ .pZwhb
bStop = true; ?_IRO|
} fn)c&|aCt
mjfU[2
MbYAK-l.h
} H'GyWG|Wx
{/N4/gu
))<3+^S0V\
/* RV-7y^[]^
**FileAccess.java 7cH[}v`pn
*//文件访问(定位，写) %c):^;6p
package NetFox; ]*?qaIdqu
import java.io.*; D3$}S{Yw1
\xwE4K
9 u{#S}c`
public class FileAccessI implements Serializable{ ~!\n
|nIm$p'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7i`8 c =.
RandomAccessFile oSavedFile; :`25@<*u
long nPos; -W2 !_
L]cZPfI6
ZdfIe~Oni
public FileAccessI() throws IOException lIz"mk
{ s-[_%
this("",0); xDm^f^}>
} =JY9K0S~
wj/OYnMw
&jr'vS[b
public FileAccessI(String sName,long nPos) throws IOException 8sLp! O;f2
{ b+,u_$@B
oSavedFile = new RandomAccessFile(sName,"rw"); qhc3 oRe
this.nPos = nPos; wpO-cJ!,
oSavedFile.seek(nPos); 46Vx)xX
} YQLp#
(=,p"3^
l-g+E{ZM
public synchronized int write(byte[] b,int nStart,int nLen) \^i/:
{ C[gy{40}
int n = -1; CNQ>J`4
try{ yc?+L;fN
oSavedFile.write(b,nStart,nLen); C[z5& x2
n = nLen; P >HEV a
} va[@XGaC3
catch(IOException e) )Z2HzjE
{ X H,1\J-S
e.printStackTrace (); F<VoPqHq
} Q0s!]Dk
*H8(G%a!^
$ac VJI?
return n; ,SNN[a
} D<78Tm x
?VmEbl
]X%T^3%G
} 9q(*'rAm
>fNRwmi
V*U{q%p(
/* Ey4%N`H-^
**SiteInfoBean.java bVaydJ*
*/ gP:mZ7
package NetFox; kdcr*7w
]lV\D8#
PRa#;Wb
public class SiteInfoBean { 5ELKL#(
Zl^#U c"
bxLeQWr6
private String sSiteURL; //Site's URL +zn&DG0\X
private String sFilePath; //Saved File's Path U=QfInB
private String sFileName; //Saved File's Name Z:j6AF3;
private int nSplitter; //Count of Splited Downloading File =8#$'1K,v
w,f1F;!q1
'7Q5"M'
public SiteInfoBean() z]:{ruvH
{//nSplitter的缺省值为5 qVjl8%)
//default value of nSplitter is 5 .93B@u
this("","","",5); 2j*;1
} d[eN#<
EFSln*|
(r78AZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qRC-+k:
{ oP vk ^H
sSiteURL= sURL; '@t}8J
sFilePath = sPath; K)"lq5nM
sFileName = sName; 0Rgo#`7l
this.nSplitter = nSpiltter; ='"DUQH|*
b}s)3=X@q
g?-HAk6
} csABfxib
ay4E\=k
9[31EiT
public String getSSiteURL() 6_1v~#
{ |:Q`9;
return sSiteURL; :.u[^_
} tgz
<Wqk5mR
AT$eTZ]M
public void setSSiteURL(String value) Cp{ j+Ia
{ Ky(=O1Ufu
sSiteURL = value; ixJ%wnz
} C 0@tMB7
MhT.Zg\
ti%uyXfja
public String getSFilePath() #ub!
{ 2g?O+'JD
return sFilePath; iY_E"$}P
} I#?NxP\S
u^5X@.
98"/]ERJ
public void setSFilePath(String value) [R-&5 G!x
{ GO3F[l
sFilePath = value; Y367Jr@^N
} EkWipF(
wX7|a/|@
c:>&iB-Yu
public String getSFileName() k(As^'>
{ 1"7Rs}l7
return sFileName; e&*< "WN
} |^ K"#K
q4Z9;^S
e;_ cC7
public void setSFileName(String value) CB&$tDi
{ '(N -jk
sFileName = value; Qqju6}+
} P01o:/}
{-FS+D`
kWkAfzf4a
public int getNSplitter() YTWlR]Tr6?
{ ~x}/>-d
return nSplitter; >'\cNM~nf
} &tKr ?l
WcE{1&PXx
UM?{ba9
public void setNSplitter(int nCount) HZ>8@AVa\
{ WrzyBG_
nSplitter = nCount; i]sz*\P~
} =[X..<bW9:
} Yr7%C
iPnu *29
EUxkYl
/* 4O~E4" ]
**Utility.java ?=C?3R
*/ <[N"W82p
package NetFox; w"p,6Ew
e@B+\1
JYQ.Y!X1O
public class Utility { 7x,c)QES`
67916
)qi/>GR,
public Utility() *&iSW~s
{ [5KzawV
4s{_(gy
y]z^e\qc)
} WGG Va
mn5"kYy?
//线程睡眠 3F/05}d`
public static void sleep(int nSecond) ]yzqBbV
{ }M9R5!=q
try{ }PdHR00^
Thread.sleep(nSecond); A>SXc%K
} ,<,ige
catch(Exception e) fevLu[,
{ iGCA>5UE
e.printStackTrace (); A(!nT=0o
} /~k)#44
} {|{}]B
y(I_ 6+B^
//日志 ]{` 8C
public static void log(String sMsg) M!KHBr
{ 8UAbTqB-
System.err.println(sMsg); ulcm
} 8(GH.)I+0
Mo4#UV
<ZF,3~v?
public static void log(int sMsg) F0cde
{ %TO=]>q
System.err.println(sMsg); ct,Iu+HJ
} m5m'ByX(*
} Y5J}*`[Mr
@O~
;H%&Jht
/* T2;%@Ghc
**TestMethod.java hWzjn5w3
*/ j\,HquTR
package NetFox; 37#|X*L
KK}?x6wV0,
=N_7DT
public class TestMethod { P|rsq|',
Afpj*o
41pk )8~pt
public TestMethod() l~f>ve|
{ ///xx/weblogic60b2_win.exe RC[b+J,q
try{ SAuZWA4g[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H(eGqVAq,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M7$ h
SiteFileFetch fileFetch = new SiteFileFetch(bean); Mn<G9KR
fileFetch.start(); y;0k |C
} !OM P]
catch(Exception e){e.printStackTrace ();} .d\<}\zZ7J
GrwoV~
ul{u^ j
} 6]GEn=t
[G(}`u8w"
_`Ojh0@00
public static void main(String[] args) WK{{U$:$
{ {l/]+8G^
new TestMethod(); <NIg`B@'s
} /7EeM{,~
} 3YtFO;-
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