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)); YM`pNtQ
} p &>A5
for(int i=0;i<nEndPos.length-1;i++) /;AZ/Ocy!
{ 1G%PXrEj8
nEndPos = nStartPos[i+1]; l&*)r;9
} y?n2`l7f
nEndPos[nEndPos.length-1] = nFileLength; UMuuf6
} EWIc|b:
} kLt9;<L
;#s}b1
2BDan^:-Av
//启动子线程 Wi[m`#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :z.Y$]F@
for(int i=0;i<nStartPos.length;i++) drKjLo[y
{ 9xn23*Fo
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S tnv>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :KSor}t
nStartPos,nEndPos,i); vo ;F;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t-i6FS-
fileSplitterFetch.start(); ]<T8ZA_Y;
} Jh4&Qh|t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3;MjO*-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xDJ+BQ<1A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l(#ke
nEndPos = " + nFileLength); yW^IN8fm
// fileSplitterFetch[nPos.length-1].start(); IT`=\K/[4
^qO=~U!{
!UoU#YU
//等待子线程结束 /;&+< }
//int count = 0; 8ts+'65|F
//是否结束while循环 vA"niO
boolean breakWhile = false; c5E#QV0&v~
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RO{@RhnV
while(!bStop) iv:/g|MBI&
{ a4(?]ND~6
write_nPos(); ]}[Yf
Utility.sleep(500); kAN;S<jSE
breakWhile = true; eR-=<0Iw;
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q{cp|#m#G
for(int i=0;i<nStartPos.length;i++) {HHh.K
{ r1oku0o
if(!fileSplitterFetch.bDownOver) ]hE+$sKd
{ .S!>9X,
breakWhile = false; 5m^Hi}S_
break; a-5HIY5
} "f|(@a
} >u5g?yzw
if(breakWhile) AB"1(PbG
break; 'DzBp
8.CKH4h
~#"7,rQp
//count++; aLKMDiT
//if(count>4) v0`qMBr1y
// siteStop(); #_?TIY:h
} 'sRg4?PT
3G%wZ,)C
qA/#IUi)1
System.err.println("文件下载结束！"); mT6q}``vtG
} /e|[SITe
catch(Exception e){e.printStackTrace ();} Jf?S9r5Q
} Er"R;l]xJ
U.RW4df%E
lMBX!9z
//获得文件长度 \ I^nx+l
public long getFileSize() W""*hJ
{ O[IR|
int nFileLength = -1; 4r1<,{gCS
try{ NTm<6Is`
URL url = new URL(siteInfoBean.getSSiteURL()); RQ^m6)BTo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CYtjY~
httpConnection.setRequestProperty("User-Agent","NetFox"); | "Jx
j?\$G.Y
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int responseCode=httpConnection.getResponseCode(); d$fvg8^
if(responseCode>=400) "($Lx
{ 9jO`gWxV8*
processErrorCode(responseCode); &_9YLXtMi;
return -2; //-2 represent access is error 4[TS4p
} VyecTU"W
C5es2!^-]O
"H>r-cyh
String sHeader; 894r;UA7
q Vm"f,ruo
4D^ M<Xn
for(int i=1;;i++) =`qRu
{ #%?FM>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -uA3Y
//Utility.log(in.readLine()); Z}8k[*.
sHeader=httpConnection.getHeaderFieldKey(i); ]By0Xifew
if(sHeader!=null) |*^8~u3J"
{ uW}Hvj;0a*
if(sHeader.equals("Content-Length")) M=5d95*-}
{ =U4f}W;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &|Lh38s@$#
break; #puQi
} ih>a~U<
} Z+Yeg
else (9mbF%b
break; VK2@2`$
} :`0'GM" `
} l`@0zw+
catch(IOException e){e.printStackTrace ();} oL<BLr9>
catch(Exception e){e.printStackTrace ();} 3ty4D2y
k"">2#V
"7=bL7wM&
Utility.log(nFileLength); ;asm 0H(
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w4\BD&7V
return nFileLength; P<%v+O
} -xJX_6}A
Ci~f#{
tm(v~L%$>]
//保存下载信息（文件指针位置） JY{X,?s
private void write_nPos() tg~A}1o`0
{ 7\IL
try{ C,o:
output = new DataOutputStream(new FileOutputStream(tmpFile)); VmN}FMGN
output.writeInt(nStartPos.length); DH5bpg&T
for(int i=0;i<nStartPos.length;i++) b,#`n
{ 8y$5oD6g9
// output.writeLong(nPos); m</]D WJ
output.writeLong(fileSplitterFetch.nStartPos); }>2t&+v+
output.writeLong(fileSplitterFetch.nEndPos); gaQ[3g
} NW z9C=y
output.close(); N0+hejz
} b-PSm=`
catch(IOException e){e.printStackTrace ();} D=$4/D:;
catch(Exception e){e.printStackTrace ();} kMM'[w
} jcE Msc
'KH lrmnr
.iFViVZC
//读取保存的下载信息（文件指针位置） ^6Yd}
private void read_nPos() ~gP7s_qr{
{ qQ^d9EK'?~
try{ swttp`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]k[x9,IU\y
int nCount = input.readInt(); E W`W~h[
nStartPos = new long[nCount]; jDR')ascn
nEndPos = new long[nCount]; P{?;T5ap6
for(int i=0;i<nStartPos.length;i++) lbRzx4=\y
{ zm>>} 5R
nStartPos = input.readLong(); Gb;99mE
nEndPos = input.readLong(); z&O#v9.NE|
} elu=9d];@
input.close(); )1WMlG
} Z a! gbt
catch(IOException e){e.printStackTrace ();} `19qq]
catch(Exception e){e.printStackTrace ();} U_]=E<el
} yE#g5V&
4sTMgBzw
Tr~sieL
private void processErrorCode(int nErrorCode) rWA6XDM7
{ I?B,sl_w
System.err.println("Error Code : " + nErrorCode); 42&v% ;R
} ML=eL*}l
J,??x0GDx,
wTxbDT@H5
//停止文件下载 I_ONbJ9]
public void siteStop() dPsLZ"I
{ }MP>]8Aq
bStop = true; ]Ko^G_Rm
for(int i=0;i<nStartPos.length;i++) _BbvhWN&+
fileSplitterFetch.splitterStop(); n+2%tW
P$_&
~(P&g7u
} ,]ga[
} 30s; }
//负责部分文件的抓取 D93gH1z
**FileSplitterFetch.java {Ur7#h5
*/ gljo;f:
package NetFox; V@[rf<,
m^<p8KZ
|jsb@
import java.io.*; uAUp5XP|Z
import java.net.*; |d[5l^6
dN< ,%}R
$E\^v^LW
public class FileSplitterFetch extends Thread { w9MoT.kI}
M7rIi\4K4
zEj#arSE4
String sURL; //File URL ?E6^!4=,
long nStartPos; //File Snippet Start Position qw<HY$3=
long nEndPos; //File Snippet End Position /&r|ec5
int nThreadID; //Thread's ID TN\|fzj
boolean bDownOver = false; //Downing is over R:M,tL-l
boolean bStop = false; //Stop identical h$`#YNd'
FileAccessI fileAccessI = null; //File Access interface nBkh:5E5%
O#)jr-vXdV
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X3',vey
{ A|L'ih/
this.sURL = sURL; iPvuz7j=h
this.nStartPos = nStart; V^TbP.
this.nEndPos = nEnd; Ird|C[la
nThreadID = id; 2s\BY%XY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /,2rjJ#b
} $5NKFJc
py @( <
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public void run() vQ1 v#Z
{ nn+_TMu
while(nStartPos < nEndPos && !bStop) u#@RM^738d
{ 2z\e\I
(5a1P;_Y
rQb7?O@-
try{ ; b*i3*!g
URL url = new URL(sURL); Y%@hbUc}x9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \vRd}
httpConnection.setRequestProperty("User-Agent","NetFox"); GSi>l,y'
String sProperty = "bytes="+nStartPos+"-"; "hQgLG
httpConnection.setRequestProperty("RANGE",sProperty); #$E)b:xj
Utility.log(sProperty); jo9gCP.
((bTwx
O$D?A2eI
InputStream input = httpConnection.getInputStream(); uOd&XW
//logResponseHead(httpConnection); K\u_Ji]k
=n+ \\D
eTbg7"waA
byte[] b = new byte[1024]; A%XX5*
int nRead; rS7)6h7(7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v-Qmx-N
{ r^1+cwy/7P
nStartPos += fileAccessI.write(b,0,nRead); X!>eiYK)
//if(nThreadID == 1) r@kP*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |ZiC`Nt
} %S \8.
`\CVV*hP
SwW['c'*]B
Utility.log("Thread " + nThreadID + " is over!"); H43MoC
bDownOver = true; =r9r~SR#
//nPos = fileAccessI.write (b,0,nRead); G8J*Wnwu[K
} 2VoKr)
catch(Exception e){e.printStackTrace ();} KzV 2MO-$
} aG%,cQ1
} F(,UA+$A
Qdf=XG5
2=iH$v
//打印回应的头信息 Vsnuy8~k
public void logResponseHead(HttpURLConnection con) 5Qh?>n>*
{ [p;E~-S
for(int i=1;;i++) `5~3G2T
{ B9,^mE#
String header=con.getHeaderFieldKey(i); 5d\q-d
if(header!=null) XYrJ/!*.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); = ieag7!
Utility.log(header+" : "+con.getHeaderField(header)); 2RM+W2!!
else 0#*Lw }qi
break; .6f%?oo
} '#/G,%m<!i
} >>{FzR
Ch \&GzQ
hrGH}CU"
public void splitterStop() YXo|~p;=Y
{ Pr ]Ka
bStop = true; uxaYCa?
} ^Yj xeNY
y|wlq3o
~m^ #FJu
} ^vilgg~
L;Z0`mdz
??60,m:]
/* qqrq11W
**FileAccess.java svf|\p>]H
*//文件访问(定位，写) jz58E}
package NetFox; ?L&|Uw+
import java.io.*; rgmF:C
9o*,P,j'}
O3DmNq$dz
public class FileAccessI implements Serializable{ 7\FXz'hA
,JU@|`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G)v #+4
RandomAccessFile oSavedFile; W6H,6v
long nPos; l<0}l^C.
+5VLw
QTX8 L
public FileAccessI() throws IOException w@JKl5
{ 8{`?=&%6
this("",0); 1$qh`<\
} ,1OyN]f3
c:Wze*vI;
om?-WJI
public FileAccessI(String sName,long nPos) throws IOException g<{xC_J
{ )q7UxzE+
oSavedFile = new RandomAccessFile(sName,"rw"); m<FOu<y
this.nPos = nPos; 8#!i[UFdj
oSavedFile.seek(nPos); 5%sE]Y#
} 2MZCw^s>
Vq;dJ%sY
;4N;D
public synchronized int write(byte[] b,int nStart,int nLen) >h0-;
{ M9zfT!-
int n = -1; J+d1&Tw&
try{ ok|qyN+
oSavedFile.write(b,nStart,nLen); V,rq0xW
n = nLen; 3gd&i
} oy<WsbnS
catch(IOException e) 8JmFi
{ (=~&+z
e.printStackTrace (); V3 ~~
} P ;IrBq6|o
y WV#Up
AL>$HB$
return n; Jgnhn>dHe
} T)r9-wOq
Yn8=
C z\Ppq
} t%F0:SH
)iFJz/n>
/cU<hApK
/* Um&(&?Xf
**SiteInfoBean.java J9~g|5
*/ /0Ax*919j
package NetFox; c("_bOAT
S)DnPjN{
pb~pN
public class SiteInfoBean { dAy?EO0\7
Q-1vw6d
r Tz$^a}/
private String sSiteURL; //Site's URL OpHsob~
private String sFilePath; //Saved File's Path C*P7-oE2rh
private String sFileName; //Saved File's Name B(M6@1m_
private int nSplitter; //Count of Splited Downloading File rtc9wu
l\C.",CEcc
=UV`.d2[
public SiteInfoBean() u*hSj)vr1
{//nSplitter的缺省值为5 Z?\>JM >;
//default value of nSplitter is 5 B ~OZ2-~
this("","","",5); fkac_X$7
} *QH28%^
1dK*y'rx
-Z's@'*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VNY%R,6
{ <>Hj ;q5p
sSiteURL= sURL; (DI>5.x"
sFilePath = sPath; P-9<YN
sFileName = sName; :Y[LN
this.nSplitter = nSpiltter; <i,U )Tt^C
)==Jfn y
WYr/oRO
} aTt12Sc
'*3h!lW1.
kBffF@{
public String getSSiteURL() j:VbrR
{ b9l;a+]d
return sSiteURL; OLE[UXD-E
} k?,1x~
^0 -:G6H
:5{wf Am
public void setSSiteURL(String value) DP|D\+YyYA
{ xoN3
sSiteURL = value; i*Z"Me
} -PfX0y9n
mGK|ihYu
cI4K+
public String getSFilePath() u?}(P_9
{ b}"N`,0dO
return sFilePath; }|pwz
} R#I0|;q4|p
1]p ZrBh"E
:>C2gS@
public void setSFilePath(String value) 0.@&_XTPl
{ "/wyZ
sFilePath = value; h-[VH%
} $69oV:
=o$sxb E(
y]f"@9G#
public String getSFileName() 2I,^YWR
{ 9J2NH|]c
return sFileName; W>j!Q^?
} M r5v<
c_4[e5z
^y<<>Y'I
public void setSFileName(String value) xjKR R?
{ GU( _
sFileName = value; `)_dS&_\
} r2,.abo
a m|F?|1
73/P&hT
public int getNSplitter() *Qg_F6y
{ >LOjV0K/
return nSplitter; f}9zgWU
} f,kZ\Ia'r
']2E {V
mjW8Q\D
public void setNSplitter(int nCount) aWR}R>E
{ ,X`)ct
nSplitter = nCount; 6">+ ~ G
} xHD=\,{ig
} 2#c<\s|C
"eB$k40-
uM_wjP
/* @`q:IIgW
**Utility.java h4T5+~rw
*/ Bu#VMkchJ
package NetFox; wAf\|{Vn
qVH1}9_
.\)U@L~
public class Utility { NQJq6S4@
[OC5l>
E2R&[Q"%
public Utility() 6ZP(E^.
{ < t,zaIi
leTf&W
W\d{a(*
} =THpdtL
J IUx
//线程睡眠 JB<Sl4
public static void sleep(int nSecond) um!J]N^
{ Rh_np
try{ n\*!CXc
Thread.sleep(nSecond); |)(VsVG&
} E&2OD [iX
catch(Exception e) S4Y&
{ u)}$~E>
e.printStackTrace (); UC]\yUK1J
} 0IBhb(X
} Lr$go6s
~A'!2
//日志 pNepC<rY
public static void log(String sMsg) xhVO3LW'
{ jB%lB1Q|
System.err.println(sMsg); n<O}hM ZT
} vHry&#Pl+
}$SavB#SBP
k_ & :24Lj
public static void log(int sMsg) mr*JJF0Z
{ ON=@O
System.err.println(sMsg); 7%Gwc?[x
} J??-j
} g jDh?I
K1 EynU I
I>]oS(GNT
/* lr>oYS0
**TestMethod.java 5m\<U`
*/ 8']M^|1
package NetFox; M+||rct
q&s3wDl/
,(d)Qg
public class TestMethod { Wbr|_W
!t$'AoVBq
2Rw&C6("w
public TestMethod() sFT.Oxg<
{ ///xx/weblogic60b2_win.exe \<JSkr[h!"
try{ >s>1[W@*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 52:HNA\E/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]O+Ma}dxz:
SiteFileFetch fileFetch = new SiteFileFetch(bean); #5cEV'm;
fileFetch.start(); +ga k#M"n\
} HHDl8lo
catch(Exception e){e.printStackTrace ();} DFZkh^PFd
I`-8Air5f
5na~@-9p
} ;RDh~EV
@XLy7_}
`Q|*1
public static void main(String[] args) [Dk=? +
{ KHe=O1 %QO
new TestMethod(); *X'Y$x>f
} adCU61t
} -lbm* -(
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