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)); Moldv x=M
} A`5/u"]*D
for(int i=0;i<nEndPos.length-1;i++) WfdM~k\
{ ?{)sdJe
nEndPos = nStartPos[i+1]; /Zzb7bHLK
} IInsq
nEndPos[nEndPos.length-1] = nFileLength; v+), uj
} 6w?l I
} bNH72gX2Yh
tom1u>1n
P' ";L6h
//启动子线程 @]{+9m8G@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IIZu&iZo\
for(int i=0;i<nStartPos.length;i++) wsfN \6e
{ zL^`r)H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Kyr3)1#J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O_E\(So
nStartPos,nEndPos,i); 0xN1Xm0d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u{asKUce\
fileSplitterFetch.start(); 6\+ZTw
} jD<fu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M1Frn n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lc:dKGF6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (plsL
nEndPos = " + nFileLength); E43Gk!/|(
// fileSplitterFetch[nPos.length-1].start(); Wl29xY}`{!
We8n20wf<
@W_=Z0]
//等待子线程结束 o+wG69
//int count = 0; WR;)
//是否结束while循环 Gz_[|,i
boolean breakWhile = false; &7fwYV
(G E)
u|G&CV#r
while(!bStop) vqeWt[W v
{ XEUy,>mR
write_nPos(); S-5|t]LV
Utility.sleep(500); 9Kpzj43
breakWhile = true; F0D7+-9[
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Yn~N;VUA
for(int i=0;i<nStartPos.length;i++) 8et*q3D7`
{ brdfjE8
if(!fileSplitterFetch.bDownOver) ,GU|3
{ un&Z' .
breakWhile = false; ~xp(k
break; SU`RHAo
} >u-6,[(5X*
} K> rZJ[a
if(breakWhile) P3W<a4 ==
break; ^zfO=XN
sC< B
nt5x[xa
//count++; C.#\Pz0
//if(count>4) US.7:S-r"
// siteStop(); q^I/
} h1A/:/_M6
pBbfU2p
$:4*?8K2
System.err.println("文件下载结束！"); 2#XYR>[
} Jc3Z1Tt
catch(Exception e){e.printStackTrace ();} hoDE*>i
} +H4H$H
NDqvt$
j "^V?e5
//获得文件长度 2!Gb4V
public long getFileSize() O^2@9 w
{ hoOT]Bsn
int nFileLength = -1; M'gL_Xsei
try{ ~vGX(8N
URL url = new URL(siteInfoBean.getSSiteURL()); T'K6Q cu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $;V?xZm[
httpConnection.setRequestProperty("User-Agent","NetFox"); zxo" +j4Ym
+n>_NVe
!D \u2h
int responseCode=httpConnection.getResponseCode(); h(>eHP
if(responseCode>=400) P<OSm*;U:
{ fecV[
processErrorCode(responseCode); 7gx 7NDt
return -2; //-2 represent access is error qs|{
} k%gO
O/N@Gz[g%
V~~4<?=A
String sHeader; >Av[`1a2F
p-S&Wq
45qSt2
for(int i=1;;i++) K.R4.{mo
{ f)b+>!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Dus [N< w
//Utility.log(in.readLine()); A@?Rj
sHeader=httpConnection.getHeaderFieldKey(i); ?b,x;hIO
if(sHeader!=null) jfOqE*frl!
{ 5.TeH@(
if(sHeader.equals("Content-Length")) 3+uCTn0%
{ C@ns`Eh8w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BB.^[:,dA
break; *^@{LwY\M
} d'okXCG
} d$?sS9"8(
else %Ums'<xJ
break; !,0%ZG}]7
} :,f~cdq=
} ;dR4a@
catch(IOException e){e.printStackTrace ();} ALO0yc
catch(Exception e){e.printStackTrace ();} })#SjFq<V
iL6Yk @
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Utility.log(nFileLength); $-Yq?:
Af`qe+0E
6`JY:~V"
return nFileLength; Ob~7r*q
} bZKlQ<sI
6]D%|R,Q#}
h@H8oZ[
//保存下载信息（文件指针位置） IHs^t/;Iv
private void write_nPos() F^/b!)4X
{ MJ..' $>TC
try{ )zK6>-KWA
output = new DataOutputStream(new FileOutputStream(tmpFile)); CBrC
output.writeInt(nStartPos.length); A7c*qBt
for(int i=0;i<nStartPos.length;i++) <5t2+D]]}
{ kM;fxR:-
// output.writeLong(nPos); u;/5@ADW
output.writeLong(fileSplitterFetch.nStartPos); V0O6\)/.
output.writeLong(fileSplitterFetch.nEndPos); @}oY6cW;B*
} .G~Y`0
output.close(); _s%;GWj
} GLpl
catch(IOException e){e.printStackTrace ();} x[dR5
catch(Exception e){e.printStackTrace ();} YKV?I
} ^fq^s T.$
v{44`tR
[/+}E X
//读取保存的下载信息（文件指针位置） = 9K5f#;e
private void read_nPos() `v"p""_H
{ 5IJm_oy
try{ 4b/>ZHFOF;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m.g2>r`NU
int nCount = input.readInt(); [(kC/W)!
nStartPos = new long[nCount]; QrSF1y'd
nEndPos = new long[nCount]; ,|lDR@
for(int i=0;i<nStartPos.length;i++) $E,,::oJ
{ ,Qb(uirl]
nStartPos = input.readLong(); g7-*WN<
nEndPos = input.readLong(); J4l\
} vS1#ien#
input.close(); 02RZ>m+
} CUI\:a-
catch(IOException e){e.printStackTrace ();} K4w#}gzok
catch(Exception e){e.printStackTrace ();} N7l`-y
} 6M^NZ0~J
_B6W:k|-7l
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private void processErrorCode(int nErrorCode) h|Ah\P?o
{ D9 \!97
System.err.println("Error Code : " + nErrorCode); !$Whftg
} 0tS< /G8
Pz77\DpFi
NQu.%=
//停止文件下载 (aUdPo8H^
public void siteStop() d [f,Nu'
{ aJ3.D
bStop = true; }c?W|#y`.o
for(int i=0;i<nStartPos.length;i++) *2^+QKDG
fileSplitterFetch.splitterStop(); S"Z.M _
5oTj^W8M(
;_dOYG1
} TO5#iiM)
} (`cXS5R
//负责部分文件的抓取 !V O^oD7
**FileSplitterFetch.java 'L5ih|$>
*/ *I<L1g%9d
package NetFox; BTAt9Z8qK
3vC"Q!J&
4 >`2vb
import java.io.*; /73ANQ"
import java.net.*; C &~s<tcn
hYSzr-)
Pu0 <Clh
public class FileSplitterFetch extends Thread { ~zO>Q4-k
sBq6,Iu
K*sav?c
String sURL; //File URL ZFFKv
long nStartPos; //File Snippet Start Position O =gv2e
long nEndPos; //File Snippet End Position ]*v[6 +
int nThreadID; //Thread's ID GC3WB4iY@U
boolean bDownOver = false; //Downing is over SCq:jI
boolean bStop = false; //Stop identical }v4T&/vt-
FileAccessI fileAccessI = null; //File Access interface I3^}$#>
<_ruVy0]
{^*K@c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j0uu*)Rk
{ u5O`|I@R
this.sURL = sURL; S9kA69O
this.nStartPos = nStart; N?j#=b+D
this.nEndPos = nEnd; lK"m|Z
nThreadID = id; $VNj0i. Pr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yR$ld.[uf
} jzb%?8ZJ
|6o!]~&e$1
L )53o!
public void run() (kmrWx= $
{ !4vepa}Y
while(nStartPos < nEndPos && !bStop) n]x%xnt
{ `)TuZP_)
mzm{p(.
WvN{f*
try{ i1JVvNMQ,
URL url = new URL(sURL); 0?Bv zfb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >)*0lfxTZ
httpConnection.setRequestProperty("User-Agent","NetFox"); ]WvV*FL9D3
String sProperty = "bytes="+nStartPos+"-"; S>;+zVF]
httpConnection.setRequestProperty("RANGE",sProperty); ,TlYQ/j%h
Utility.log(sProperty); 1haNpLfS>
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epGC Ta
InputStream input = httpConnection.getInputStream(); IcJQC
//logResponseHead(httpConnection); =OamN7V=
&B?*|M`)k
F&u)wI'
byte[] b = new byte[1024]; wB+X@AA
int nRead; ;2}wrX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;)23@6{R%
{ $i|d=D&t
nStartPos += fileAccessI.write(b,0,nRead); wzf
//if(nThreadID == 1) pB:/oHV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0Z1';A3
} Id^)WEK4
,(;]8G-Yj
:y1,OR/k
Utility.log("Thread " + nThreadID + " is over!"); #5yz~&
bDownOver = true; HAmAmEc,
//nPos = fileAccessI.write (b,0,nRead); FjV)QP H
} V/Q/Ujgg
catch(Exception e){e.printStackTrace ();} F10TvJ U
} [9d4 0>e
} `Rx\wfr}
%V|n2/O Y
/2>.*H_2
//打印回应的头信息 NnRX0]
public void logResponseHead(HttpURLConnection con) &a!MT^anA~
{ !X4m6gRaP
for(int i=1;;i++) CLgfNrW~
{ E RjMe'q4
String header=con.getHeaderFieldKey(i); k"F\4M
if(header!=null) 2#Du5d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NCivh&HR
Utility.log(header+" : "+con.getHeaderField(header)); dZ|x `bIgs
else $&X-ay o
break; Dg}$;PK
} Mhu|S)hn
} N oRPvFv
oH;9s-Be
s<{) X$
public void splitterStop() F% z$^ m-
{ _6.Y3+7I
bStop = true; yY_#fJj
} bKt4
"sYZ3
|f3 :9(p
} Z '~Ie~
bD`h/jYv
+1nzyD_E
/* 'x<o{Hi"\B
**FileAccess.java (W |;gQ
*//文件访问(定位，写) b6!7j
package NetFox; 0M!GoqaA
import java.io.*; ]Jo}F@\g
@a (-U.CZ
r"!xI
public class FileAccessI implements Serializable{ <UwYI_OX
6 IRa$h>H
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @plh'f}
RandomAccessFile oSavedFile; M{g.x4M@W
long nPos; zy`T! $
3z% W5[E)
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public FileAccessI() throws IOException 0i(c XB
{ ^s\T<;
this("",0); Y+{jG(rg.F
} NUFW SL>
_&N}.y)+t
rV}&G!V_t
public FileAccessI(String sName,long nPos) throws IOException v8K`cijSS
{ Lk.tEuj=82
oSavedFile = new RandomAccessFile(sName,"rw"); Y|S>{$W
this.nPos = nPos; :,V&P_
oSavedFile.seek(nPos); Jwpc8MQ
} %+oqAYm+s
Hu+GN3`sx^
$f=6>Kn|^]
public synchronized int write(byte[] b,int nStart,int nLen) ~l}\K10L*
{ !8&EkXTw,
int n = -1; [lGxys)J
try{ B+z>$6
oSavedFile.write(b,nStart,nLen); m qwJya
n = nLen; K[S)e!\.
} &WZ&Tt/)/
catch(IOException e) z"-oD*ICw
{ PYTwyqS
e.printStackTrace (); ;;+h4O )
} #gVWLm<
?JBA`,-
M(vX.kF
return n; W;?e@}
} OZEbs 7
intl?&wC
xlH3t&i7
} :!JQ<kV
mbns%%GJU
K>TEt5
/* 0\V)DV.i
**SiteInfoBean.java e,MgR\F}
*/ tX6_n%/L
package NetFox; n=?wX#rEC#
*fz#B/_o
10xza=a
public class SiteInfoBean { a(LtiO
FKUo^F?z
BjGfUQ
private String sSiteURL; //Site's URL q:=jv6T#
private String sFilePath; //Saved File's Path 2R W~jn"
private String sFileName; //Saved File's Name ^SK!?M
private int nSplitter; //Count of Splited Downloading File *c 9S.
/vC!__K9:
}X. Fm'`
public SiteInfoBean() %/ "yt}"|
{//nSplitter的缺省值为5 xQl}~G]!
//default value of nSplitter is 5 &G?"I%Vw
this("","","",5); n6G&c4g<"
} 2@IL n+#
%cBOi_}}~
iNc!zA4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _mJhY0Oc
{ 6s'n r7'0
sSiteURL= sURL; YRMe<upo
sFilePath = sPath; jib pZ)
sFileName = sName; &xZSM,
this.nSplitter = nSpiltter; )+ 'r-AF*
7 IJn9b
J*38GX+
} \(--$9
/pV N1Yt
3D^cPkX
public String getSSiteURL() qHT73_R
{ }=Xlac_U
return sSiteURL; gAVD-]`
} !cdY`f6x
K-@\";whF
"$D'gSoYe
public void setSSiteURL(String value) 'Lw8l `7
{ mn\A)RQ
sSiteURL = value; ZH*h1?\X
} zl| XZ
x6*y$D^B
={f8s,m)P,
public String getSFilePath() n_:EWm$\
{ pe<T"[X
return sFilePath; ]0BX5Z'
} R.DUfU"gp
\98N8p;,I
><S(n#EB
public void setSFilePath(String value) 8_o~0lb
{ |5ge4,}0
sFilePath = value; 3rd8mh&l
} W;l0GxOxQ
qHtIjtt[q
Z}t^i^u
public String getSFileName() 0Lb{HLT
{ luyu7`
return sFileName; ,p /{!BX
} k"C'8<T)'
<1B+@
pw5{=bD
public void setSFileName(String value) cx ("F/Jm
{ \q3ui}-9
sFileName = value; *A4eYHn@
} [S8*b^t4
MT:VQ>fC
UO#`Ak
public int getNSplitter() QleVW
{ z@w}+fYO
return nSplitter; JZ~wacDd
} Jgg<u#
l5~O}`gfh
mlCg&fnDB
public void setNSplitter(int nCount) 1e7I2g
{ ekU%^R<
nSplitter = nCount; (9kR'kr
} WUo\jm[yr
} 1Lk(G9CoY
ez.a
;<thEWH;Y
/* W amOg0
**Utility.java )B)f`(SA"<
*/ t1"#L_<e
package NetFox; hvQXYo>TZx
%4Qs|CM)m
{qbe ye!
public class Utility { :>r W`= e'
uv<_.Jq]
zx,9x*g
public Utility() So8 Dwz?
{ T:zM]%Xh
iRlpNsN
}ijQ*ECdl
} IGT9}24
SD{)Sq
//线程睡眠 DW78SoyedZ
public static void sleep(int nSecond) $evuL3GY#
{ Kd58'$
try{ `'sD(e
Thread.sleep(nSecond); !lo /L
} al-rgh
catch(Exception e) "tl$JbRTY
{ t*-cX
e.printStackTrace (); x#N_h0[i
} yjMN>L'
} deVnAu =
y+w,j]
//日志 {j;` wN
public static void log(String sMsg) |2@*?o"ll
{ ; :q
System.err.println(sMsg); m4m|?
} 4OQ,|Wm4G
h.F=Fhx/1
k4hk* 0Jq
public static void log(int sMsg) +xU({/
{ A_9J~3
System.err.println(sMsg); ^3S&LC 1;|
} V$w lOMp
} =-X-${/
7gZ}Qy
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/* f7][#EL
**TestMethod.java RLMn&j|?e
*/ e0(aRN{W
package NetFox; Cl9nmyf
..+#~3es#y
Uc'}y!R
public class TestMethod { )RvX}y-
g#^MO]pY
Iz#4!E|<
public TestMethod() .(.<
{ ///xx/weblogic60b2_win.exe !|i #g$
try{ ;H.V-~:P)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {GLGDEb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YzQ1c~+
SiteFileFetch fileFetch = new SiteFileFetch(bean); |\?u-O3
fileFetch.start(); PnaiSt9p?r
} kaB4[u
catch(Exception e){e.printStackTrace ();} |rwY
FE&:?
F;8Q`$n
} Q=fl!>P
%dg[ho
,xVAJ6_#
public static void main(String[] args) (IVhj^dQm
{ oD9n5/ozo
new TestMethod(); _"L6mcI6
} o0f`/ 6o
} 2M'dTXz
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