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)); rR9|6l 3
} "uuVy$6C
for(int i=0;i<nEndPos.length-1;i++) so"$m
{ Izhee%c
nEndPos = nStartPos[i+1]; _,xc[ 07
} g!$!F>[
nEndPos[nEndPos.length-1] = nFileLength; KM}f:_J*lg
} qfL~Wp2E;
} Y ;u<GOe
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<(-= 'QA
//启动子线程 $FlW1E j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0vEoGgY0*:
for(int i=0;i<nStartPos.length;i++) vy0X_DPCr
{ p<TpK )
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?]Pmxp H}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CN#+U,NZV
nStartPos,nEndPos,i); qUjmB sB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {;N,t]>8M
fileSplitterFetch.start(); 6|aKL[%6
} jGXO\:sO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;i Fz?d3;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !lf|7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ap&?r`Tu
nEndPos = " + nFileLength); 4]h =yc R
// fileSplitterFetch[nPos.length-1].start(); $ et0s;GBv
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zo+nq%=
//等待子线程结束 [q/Abz'i
//int count = 0; 2"Ecd
//是否结束while循环 @6{~05.p
boolean breakWhile = false; b%<9Sn
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while(!bStop) B8B; y^b>i
{ 0J?~N`#O|
write_nPos(); Y' %^NP}o
Utility.sleep(500); Fy`(BF\
breakWhile = true; iz8Bf;
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[z9`)VIe
for(int i=0;i<nStartPos.length;i++) aa>xIW,u
{ >#hO).`C
if(!fileSplitterFetch.bDownOver) `8^TTQ
{ CjlKMbnBH
breakWhile = false; Svondc 4
break; LXbP 2
} 4*Q#0`um
} ^.1c{0Y^0
if(breakWhile) 0Uo\wyd
break; FrTi+& <
AWP"b?^G|
k`0>36
//count++; A%`[mc]4#
//if(count>4) V'kX)$
// siteStop(); zUKmxy@
} p3 w
ptDY3n~'
NF+iza;DP
System.err.println("文件下载结束！"); Z&|Kki*
} n^z]q;IN2.
catch(Exception e){e.printStackTrace ();} :?/cPg'D
} 8-BflejX
gW-V=LV (
'yL%3h _@
//获得文件长度 Ag&0wN+jTM
public long getFileSize() H-~6Z",1
{ QA<Jr5Ys
int nFileLength = -1; XmEq2v
try{ GM3f-\/
URL url = new URL(siteInfoBean.getSSiteURL()); cm?\ -[cV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~ ip,Nl
httpConnection.setRequestProperty("User-Agent","NetFox"); S-k8jm
K{[%7AM
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int responseCode=httpConnection.getResponseCode(); nq6@6GRG
if(responseCode>=400) QlJ)F{R8il
{ yp$_/p O=2
processErrorCode(responseCode); %]>KvoA
return -2; //-2 represent access is error pgOQIzu
} @^T1XX
_~piZmkG$
5\e9@1Rc
String sHeader; "tB;^jhRs
JKGc3j,+#
Vm3v-=6
for(int i=1;;i++) !Cr(Pe]
{ $4/yZaVb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .u4 W /
//Utility.log(in.readLine()); ig/%zA*Bo
sHeader=httpConnection.getHeaderFieldKey(i); -?mfE+kt
if(sHeader!=null) Z/t+8;TMR,
{ (>r[-Bft
if(sHeader.equals("Content-Length")) Cq%IE^g<
{ pov)Z):}G<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gLy&esJl1
break; #wV8X`g
} ](&{:>RNJ
} O+]Ifm[
else ;`^WGS(3.%
break; ;~D)~=|ZZ
} 7PtN?;rP
} ^R# E:3e
catch(IOException e){e.printStackTrace ();} [N/"5 [
catch(Exception e){e.printStackTrace ();} h&--,A >
%`r?c<P}
N7O-2Z *
Utility.log(nFileLength); 9D7+[`r(-
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hJZV}a|
return nFileLength; y *fDwd~
} f}x.jxY?
22.8PO0
Bs O+NP
//保存下载信息（文件指针位置） prTw'~(B
private void write_nPos() FLGk?.x$\
{ Zo g']=
try{ ;xzUE`uUfJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); q U]gj@R
output.writeInt(nStartPos.length); kzt(i Y_6
for(int i=0;i<nStartPos.length;i++) MP!d4
{ PX<J&rx
// output.writeLong(nPos); hFH*B~*:#
output.writeLong(fileSplitterFetch.nStartPos); )?X-(4
output.writeLong(fileSplitterFetch.nEndPos); v 8$>rwB
} (=* cK-3
output.close(); R,pX:H&#+
} TrLu~4
catch(IOException e){e.printStackTrace ();} k3)dEH1z
catch(Exception e){e.printStackTrace ();} mg*qiScfW
} UFp,a0|
oxz OA
x "^Xj]-
//读取保存的下载信息（文件指针位置） 0V'nK V"|
private void read_nPos() Mf&{7%
{ (]Y 5eM
try{ rvXWcu-"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K95p>E`9e
int nCount = input.readInt(); SjwyLc
nStartPos = new long[nCount]; cp#JBHO
nEndPos = new long[nCount]; P!+'1KR
for(int i=0;i<nStartPos.length;i++) cm&I* 0\
{ `C$:Yf]%nG
nStartPos = input.readLong(); bO'Sgc[]
nEndPos = input.readLong(); @I_8T$N=
} =8; {\
input.close(); aC%m-m
} aVK3?y2
catch(IOException e){e.printStackTrace ();} *Df,Ijh$
catch(Exception e){e.printStackTrace ();} \E%'Y
} r=X}%~_8X
qoj$]
S"OR%
private void processErrorCode(int nErrorCode) "CUty"R8
{ 1n:8s'\
System.err.println("Error Code : " + nErrorCode); DGAX3N;r6{
} c6X}2a'
w8Sp<6*
1oN^HG6O
//停止文件下载 ENGg ~D
public void siteStop() /+\uqF8F
{ dt`{!lts'
bStop = true; -Xxqm%([71
for(int i=0;i<nStartPos.length;i++) x)rM/Kq
fileSplitterFetch.splitterStop(); K)Q]a30
<xgTS[k
ML( Eo
} %2XHNW
} rld67'KcE
//负责部分文件的抓取 `eIenA
**FileSplitterFetch.java rmE"rf
*/ W!6qqi{
package NetFox; .)<(Oj|4
j}~86JO+Cw
2Fq<*pxAY
import java.io.*; BPdfYu,il
import java.net.*; 34d3g
\hM|(*DL
WIv?}gi: X
public class FileSplitterFetch extends Thread { =y/8^^
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b#K:_ac5
String sURL; //File URL ? P( ZA
long nStartPos; //File Snippet Start Position BI $
long nEndPos; //File Snippet End Position " e}3:U5n
int nThreadID; //Thread's ID rfNm&!K
boolean bDownOver = false; //Downing is over {|1Y:&M?
boolean bStop = false; //Stop identical .8y3O]
FileAccessI fileAccessI = null; //File Access interface lsy?Ac
t=-SH^$SR
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +eX@U;J,g
{ qeL5D*
this.sURL = sURL; JvT"bZk(o
this.nStartPos = nStart; "87ghj_}
this.nEndPos = nEnd; K00 87}H
nThreadID = id; s;64N'HH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V}SBuQp"
} XI9js{p
,B0_MDA +
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public void run() 72oF,42y
{ p\JfFfC
while(nStartPos < nEndPos && !bStop) Um: Hrjw
{ /k<WNZM
4Rvf
Oh'Y0_oB>
try{ %7gkNa
URL url = new URL(sURL); R0L&*Bjm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4(1(e
httpConnection.setRequestProperty("User-Agent","NetFox"); w\DVzeW(
String sProperty = "bytes="+nStartPos+"-"; pGK;1gVj
httpConnection.setRequestProperty("RANGE",sProperty); N9vP7
Utility.log(sProperty); .]sf0S!
^",ACWF4Sk
$`-4Ax4%
InputStream input = httpConnection.getInputStream(); =Q[b'*o7
//logResponseHead(httpConnection); T+<A`k: -
`/~8}Y{
5<ux6,E1{
byte[] b = new byte[1024]; j'BMAn ?
int nRead; m q{];
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ea~:}!-P
{ ;Hj~n+
nStartPos += fileAccessI.write(b,0,nRead); Vgyew9>E
//if(nThreadID == 1) 6p?JAT5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,I_^IitN
} &bp=`=*
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Utility.log("Thread " + nThreadID + " is over!"); K"[AxB'F
bDownOver = true; 9>g,
//nPos = fileAccessI.write (b,0,nRead); W"k8KODOY
} stk9Ah
catch(Exception e){e.printStackTrace ();} y;AL'vm9
} H03jDM8Q
} &ZX{R#[L
8kIR y
=n' 4?W@
//打印回应的头信息 ^-[?#]
public void logResponseHead(HttpURLConnection con) gW1b~( fD
{ %0mMz.f
for(int i=1;;i++) SJ};TEA
{ vJU*>U,
String header=con.getHeaderFieldKey(i); K a(J52
if(header!=null) #~.w&~:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /M*a,o
Utility.log(header+" : "+con.getHeaderField(header)); zdEPDdB
else }LijnHH.
break; LI6hEcM=
} Iz{R}#8CZ
} sPb=82~z
`QUy;%+
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public void splitterStop() Zt&6Ua[Y}
{ @bnG:np
bStop = true; K&U7H:
} z ly unJD(
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DVkB$2]
} FA}_(Hf.[
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QEu=-7@>
/* aKd+CO:
**FileAccess.java 5n ^TRB
*//文件访问(定位，写) ^-a8V'
package NetFox; d'|,[p
import java.io.*; Zb134b'
UD)e:G[Gat
9Y<#=C
public class FileAccessI implements Serializable{ C>[fB|^
A,)VM9M_l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >N?2""
RandomAccessFile oSavedFile; yx<WSgWZ[
long nPos; XbZ*&
60)iw4<wf
hAjM1UQ,Y
public FileAccessI() throws IOException d)"?mD:m/M
{ bC3 F
this("",0); 4ON_$FUe
} _%x4ty
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s#S%#LM
public FileAccessI(String sName,long nPos) throws IOException vc]cNz:mQ
{ *\o/q[
oSavedFile = new RandomAccessFile(sName,"rw"); 1<h>B:
this.nPos = nPos; Vm|Y$C
oSavedFile.seek(nPos); {" 4e+y
} p*8-W(u)
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public synchronized int write(byte[] b,int nStart,int nLen) #%FN>v3e
{ 3w!c`;c%
int n = -1; /2RajsK
try{ )Y8",Ig
oSavedFile.write(b,nStart,nLen); ZJjTzEV%^B
n = nLen; {h KjD"?
} ?9X&tK)E-
catch(IOException e) ne>g?"Pex{
{ LjH*rjS4
e.printStackTrace (); 033T>qY
} N<L`c/
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return n; 0ilCS[`b
} fof2 xcH!
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\@;\t7~
} '/I:^9
n6(.{M;
tdF9NFMD
/* A~dQ\M
**SiteInfoBean.java L}yyaM)
*/ gBf4's
package NetFox; o|j*t7
IjfxR mV
$j5,%\4<
public class SiteInfoBean { G8IY#
T'fcc6D5p
oQ7]=|
private String sSiteURL; //Site's URL /V?H4z[G
private String sFilePath; //Saved File's Path {gKN d*[*
private String sFileName; //Saved File's Name w~@-9<^K]v
private int nSplitter; //Count of Splited Downloading File (.Lrmf@hI7
lZQ/W:OE
$oLU; q%
public SiteInfoBean() %ObD2)s6:^
{//nSplitter的缺省值为5 3[XQR8o
//default value of nSplitter is 5 h)v^q: ='
this("","","",5); Ft@Wyo`^
} #2tCV't
ZE`lr+_Y
XTDE53Js&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 60Z]M+8y8
{ w&BGJYI
sSiteURL= sURL; E&B{5/rv
sFilePath = sPath; -~4+w
sFileName = sName; w^1Fi8+
this.nSplitter = nSpiltter; R1-k3;v^
= zl=SLe
?R5'#|EyX
} )n=ARDd^e
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rQP"Y[
public String getSSiteURL() @:x"]!1
{ AA:no=
return sSiteURL; 7);:ZpDv%L
} |8)Xc=Hz
t!_x(u
Be}$I_95\P
public void setSSiteURL(String value) o/,NGU
{ > 4oY3wk8
sSiteURL = value; M_``'gw
} {?{U,&
2BzqY`O
:ZxLJK9x1
public String getSFilePath() 'xFYUU]#T^
{ (}:C+p 'I
return sFilePath; :Au /2
} hFvi5I-b
9zgNjjCl]
Z v0C@r
public void setSFilePath(String value) P=H+ #
{ o7+>G~i
sFilePath = value; L<(VG{)Z
} Zwe[_z!*D
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public String getSFileName() mh;X~.98
{ Icp0A\L@
return sFileName; 8G ]w,eF
} [$ :
^^(<c,NX#M
;5<-)
public void setSFileName(String value) FyG6!t%
{ 0>!/rR7
sFileName = value; V)D-pV V
} Poa?Ej
&C-;Sa4
P ,K\
public int getNSplitter() H:a|x#"
{ AH.9A_dG
return nSplitter; /f1'm@8;
} *rqm8z50a
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2r];V'r
public void setNSplitter(int nCount) he)ulB
{ 1h"_[`L'
nSplitter = nCount; #/j={*-
} wAbp3hX
} {4ptu~8
#B\=Aa`*
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/* ^Y^"'"
**Utility.java YDiN^q7
*/ {@M14)-x>_
package NetFox; z^sST
`HUf v@5
!v!N>f4S$
public class Utility { )u@t.)ChAV
"E*8h/4u
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public Utility() {U <tc4^
{ M@?"t_e1
J"[3~&em
=8{*@>CX
} N"DY?6
?gV'(3 !
//线程睡眠 ~Sy-gaJ
public static void sleep(int nSecond) \iMyo
{ ma}}Sn)Q
try{ 6b:DJ
Thread.sleep(nSecond); $cK^23H/Fj
} +0pW/4x
catch(Exception e) PW_`qP:
{ i+~QDo(Pi
e.printStackTrace (); ~4s-S3YzaM
} Um ;kd&#x
} KR3-Hb4
:'w?ye[e
//日志 g'G8 3F
public static void log(String sMsg) 3kLOoL?
{ Kp_jy.e7&
System.err.println(sMsg); *d l"wH&
} I=YCQ VvA
$e/*/.
IYNMU\s
public static void log(int sMsg) MOV =n75
{ uFe'$vI
System.err.println(sMsg); /!bx`cKG
} ci7~KewJ*
} U5rxt^
0]a15
WzG07 2w
/* *4#on>
**TestMethod.java P`sN&Y~m
*/ Tcs3>lJ}
package NetFox; v_-ls"l
f-vK}'Z`,
* NMQ
public class TestMethod { z\[(g
q<}PM
Kcn\g.
public TestMethod() EW5]!%
{ ///xx/weblogic60b2_win.exe I2*oTUSik
try{ ^"`Z1)V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (^S5Sc=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `9EVB;
SiteFileFetch fileFetch = new SiteFileFetch(bean); L;C|ow^c
fileFetch.start(); _z:Qhe
} 'aPCb`^;w
catch(Exception e){e.printStackTrace ();} wU0K3qZL
Ak|b0l>^
&9h
} n49s3|#)G
f)tc4iV
~\bHfiIDy
public static void main(String[] args) Fhi5LhWe+.
{ *'^:S#=
new TestMethod(); %EB;1
} 0HPO"x3-O
} Q}z{AZ
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