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)); agkKm?xIL
} "Y4glomR[
for(int i=0;i<nEndPos.length-1;i++) Z#^|h0
{ [gZR}E
nEndPos = nStartPos[i+1]; &#gh :5
} JR&yaOws
nEndPos[nEndPos.length-1] = nFileLength; &"27U
} _V0%JE'
} Ho[]03
:V@)A/}uk
hsYE&Np_Q
//启动子线程 FgrVXb_q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Je2&7uR0
for(int i=0;i<nStartPos.length;i++) XJy.xI>;
{ 0_Elxc
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /iAhGY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Tow!5VAM
nStartPos,nEndPos,i); gSj0+|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B%kC>J
fileSplitterFetch.start(); ` vFDO$K
} 02NVdpo[wU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4sBvW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); guf*>qNr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )^"V}z t
nEndPos = " + nFileLength); K)+]as
// fileSplitterFetch[nPos.length-1].start(); 2+C:Em0yI
;4GGXT++L
0M&~;`W}
//等待子线程结束 19pFNg'kA
//int count = 0; gN73)uJ0
//是否结束while循环 D`'Cnt/
boolean breakWhile = false; kUT^o
~Cg7
PX2b(fR8_O
while(!bStop) iWFtb)3B
{ h+Yd \k
write_nPos(); `_i|\}tl
Utility.sleep(500); 5ug|crX
breakWhile = true; j(K)CHH
FUJ<gqL
rwio>4=
for(int i=0;i<nStartPos.length;i++) L%<]gJtrO
{ ZJF+./vN
if(!fileSplitterFetch.bDownOver) `g)
{ B*Om\I
breakWhile = false; HVhd#Q;
break; UugR
} K=}Eupn=
} v&d'ABeT
if(breakWhile) f1elzANy
break; :PY6J}:&#
1CSGG'J]E
[u^ fy<jdp
//count++; {.[EXMX
//if(count>4) G-K{
// siteStop(); mh`uvqY
} ur=:Ha
mW+5I-~
0 z]H=
System.err.println("文件下载结束！"); JP5en
} _8F;-7Sz
catch(Exception e){e.printStackTrace ();} C]l)Pz$
} bmi",UZ:F
nm]lPKU+Y
sDTw</@
//获得文件长度 aJF/y3
public long getFileSize() ~ qaT jSP
{ I&gd"F _v}
int nFileLength = -1; b!Nr
try{ 1LhZmv
URL url = new URL(siteInfoBean.getSSiteURL()); h(J$-SUs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C&%NO;Ole
httpConnection.setRequestProperty("User-Agent","NetFox"); gyV`]uqG
}bdoJ5
9V&+xbR&
int responseCode=httpConnection.getResponseCode(); [wiB1{/Ls.
if(responseCode>=400) 6A|XB3
{ yGrnzB6|
processErrorCode(responseCode); quC$<Y
return -2; //-2 represent access is error 1@|%{c&+9
} ?*r%*CL
ZU`~@.`i
` "-P g5
String sHeader; 4GeN<9~YS
r$'.$k\
]@Z nP,8
for(int i=1;;i++) ,O:p`"3`0=
{ 1ah,Zth2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,Shzew+
//Utility.log(in.readLine()); m|x_++3
sHeader=httpConnection.getHeaderFieldKey(i); :hW(2=%
if(sHeader!=null) {Oq8A.daJ
{ Ruq>+ }4
if(sHeader.equals("Content-Length")) MU2kA&LH
{ N;BuBm5K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1>Vq<z
break; v6Y[_1
} rz-61A) _
} Z(tO]tQE
else 0aI@m
break; <Kr`R+Q$DN
} NZADHO@0
} .f. tPm
catch(IOException e){e.printStackTrace ();} nN@ Ch
catch(Exception e){e.printStackTrace ();} E_[a|N"D
' S,g3
gzH;`,
Utility.log(nFileLength); * a1q M?
@JLN3
}NGP!
return nFileLength; hNkv lk'Ui
} PVdN)tG5
"oFi+']*
. .S3-(xW
//保存下载信息（文件指针位置） 3 Fy CD4#
private void write_nPos() H.C*IL9
{ ]q[(z
try{ gW4fwE^
output = new DataOutputStream(new FileOutputStream(tmpFile)); l,(:~KH|
output.writeInt(nStartPos.length); 4}cxSl]jf!
for(int i=0;i<nStartPos.length;i++) nnE'zk<"
{ V=5*)i/
// output.writeLong(nPos); I8B0@ZtV
output.writeLong(fileSplitterFetch.nStartPos); _h,_HW)G
output.writeLong(fileSplitterFetch.nEndPos); K"5q387!
} 61&{I>~1
output.close(); 7IkEud
} +oO7UWs>6
catch(IOException e){e.printStackTrace ();} $]}K;
catch(Exception e){e.printStackTrace ();} ;#IrHR*Bk
} K7(k_4
Jg{K!P|i
Y"KJ`Rx
//读取保存的下载信息（文件指针位置） W?P4oKsql*
private void read_nPos() 4${3e Sg_
{ _5(p=Zc
try{ wL>*WLfR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #2:?N8vz*
int nCount = input.readInt(); Lp@Al#X55
nStartPos = new long[nCount]; 5WxNH}{
nEndPos = new long[nCount]; (a-Lx2T
for(int i=0;i<nStartPos.length;i++) qp#Euq6
{ O0`ofFN
nStartPos = input.readLong(); AFvv+ ss
nEndPos = input.readLong(); 77aUuP7Iw
} n_LK8
input.close(); TvT>UBqj=
} ZU.E}Rn:
catch(IOException e){e.printStackTrace ();} Bz>f
catch(Exception e){e.printStackTrace ();} qvGmJN0
} COw!a\Jl
0Bkz)4R
'Z9UqEGV
private void processErrorCode(int nErrorCode) a MFUj+^
{ tQUKw@@Q
System.err.println("Error Code : " + nErrorCode); upZc~k!1\
} *&_cp]3-WF
5=p<"*zJ
*3@8,~_tp
//停止文件下载 O\Z!7UQ$
public void siteStop() L>E{~yh
{ B^zg#x#8
bStop = true; Lyn{Uag
for(int i=0;i<nStartPos.length;i++) ;~[}B v
fileSplitterFetch.splitterStop(); Z02EE-A
xw_$1 S
SK@ p0:
} F:jtzy"
} 9xw"NcL
//负责部分文件的抓取 dBovcc
**FileSplitterFetch.java H_x}-
*/ V:P]Ved
package NetFox; ;qbK[3.
A:z
52Dgul
import java.io.*; 5A|dhw
import java.net.*; #Hu##x|
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;1nXJ{jKw
public class FileSplitterFetch extends Thread { +|pYu<OY
gae=+@z
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String sURL; //File URL ZPq.|6&
long nStartPos; //File Snippet Start Position gV\Y>y4v
long nEndPos; //File Snippet End Position ZfVY:U:o>
int nThreadID; //Thread's ID Ik5V?
boolean bDownOver = false; //Downing is over ohJDu{V
boolean bStop = false; //Stop identical c{?SFwgd
FileAccessI fileAccessI = null; //File Access interface ,C0y3pL
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q2woCxB
{ Lpkx$QZ
this.sURL = sURL; #;@I.
this.nStartPos = nStart; a$^)~2U{
this.nEndPos = nEnd; R~[~(`/S
nThreadID = id; 2Kr>93O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }opMf6`w
} HUCJA-OZGL
>py[g0J
o~"Y_dLsW
public void run() 5_L,7\5#
{ vZ$E [EG}
while(nStartPos < nEndPos && !bStop) FyPG5-
{ qIQ 61><
VQG$$McJ
VSV]6$~H
try{ YPY,gR
URL url = new URL(sURL); ]$^HGmP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ME]89 T&
httpConnection.setRequestProperty("User-Agent","NetFox"); 98?O[=
String sProperty = "bytes="+nStartPos+"-"; -J#RGB{7
httpConnection.setRequestProperty("RANGE",sProperty); YTY(Et1i
Utility.log(sProperty); YhmveV
>g~IP>
^P]5@dv
InputStream input = httpConnection.getInputStream(); pBv,,d`
//logResponseHead(httpConnection); }oSgx
N$C+le
h#Z,ud_
byte[] b = new byte[1024]; }m5()@Q}a
int nRead; P{_%p<:V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M3F1O6=4j
{ K[/L!.Ag
nStartPos += fileAccessI.write(b,0,nRead); :?FHqfN?_
//if(nThreadID == 1) &N6[*7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /]-yZ0hX0O
} :Mh\;e
;PU'"MeB "
_FcTY5."S
Utility.log("Thread " + nThreadID + " is over!"); UHU ,zgM
bDownOver = true; ZUS5z+o
//nPos = fileAccessI.write (b,0,nRead); xaoR\H
} (&r` l&0
catch(Exception e){e.printStackTrace ();} [UC_
} W(4$.uZ)
} g.%} +5
s3Zt)xQ3
v#<{Y'K
//打印回应的头信息 xVX:kDX
public void logResponseHead(HttpURLConnection con) 7I&o
{ dtfOFag4_
for(int i=1;;i++) IO=$+c
{ $_TS]~y4}
String header=con.getHeaderFieldKey(i); UF }[%Sa
if(header!=null) =2QP7W3mg<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :&'jh/vRN
Utility.log(header+" : "+con.getHeaderField(header)); 9y5JV3
else RjO0*$>h
break; =_m3~=Z
} }BL7P-km
} cZ)mp`^n7
&nI>`Q'
Qo^(r$BD
public void splitterStop() I_Gz~qk6
{ !~R<Il|B
bStop = true; !.t D.(XP
} 74:~F)BP
rKFnivGT
$M!iQ"bb
} BKb#$95*
$U9]v5
q+*\'H>
/* P6La)U`VA
**FileAccess.java xfI0P0+
*//文件访问(定位，写) yE,qLiH
package NetFox; ,c?( |tF
import java.io.*; $ xHtI]T
^E8qI8s
LW.j)wB]
public class FileAccessI implements Serializable{ $o.Y zAo@
X/vyb^:U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $\/^O94-l
RandomAccessFile oSavedFile; JN`$Fq+
long nPos; HQ7g0:-^a>
K*b* ]hf{
l:JVt`A4?
public FileAccessI() throws IOException ;fW~Gb?"
{ yTK3eK
this("",0); cqJXZ.XC
} {I$iD
hwL`9.w
Z2})n -
public FileAccessI(String sName,long nPos) throws IOException [XDV-6KCE.
{ ">3t+A
oSavedFile = new RandomAccessFile(sName,"rw"); ZS(%!+M
this.nPos = nPos; +lVA$]d
oSavedFile.seek(nPos); 'xG J;pY
} !5?_)
_Z9d.-
.s,04xW\
public synchronized int write(byte[] b,int nStart,int nLen) _xm<zy{`S
{ }d>.Nj#zh
int n = -1; QKq4kAaJ!
try{ |%ZJN{!R
oSavedFile.write(b,nStart,nLen); :3D6OBkB
n = nLen; &QW&K
} _6r[msH"
catch(IOException e) 9s[
{ 0!ZaR6
e.printStackTrace (); &p_iAMn:9
} n^l*oEl
4uMMf
N"G\H<n
return n; w2XHY>6];
} z[<Na3]
Bt,'g*Cs
js Z"T
} RN[x\",
lMu-,Z="
,tg]Gt
/* $MwBt
**SiteInfoBean.java \<T7EV.
*/ H?Q--pG8
package NetFox; hE`d@
!z4I-a
sZr \mQ~
public class SiteInfoBean { }[UH1+`L
K\;4;6g
7.ein:M|CB
private String sSiteURL; //Site's URL V59!}kel1%
private String sFilePath; //Saved File's Path Db*b"/]
private String sFileName; //Saved File's Name Y,}h{*9Kd
private int nSplitter; //Count of Splited Downloading File A- Abj'
R13k2jLSQ
JeNX5bXW
public SiteInfoBean() % 33O)<?
{//nSplitter的缺省值为5 pt3)yj&XE
//default value of nSplitter is 5 DeNWh2
this("","","",5); [f lK
} $/g`{OI]K
a.gMH uL
KA{QGaZ/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $b{8$<;9
{ JU5,\3Lz#
sSiteURL= sURL; uM\\(g}
sFilePath = sPath; LA59O@r
sFileName = sName; cl]W]^q-Cx
this.nSplitter = nSpiltter; %r.C9
|;)_-=L0P
>yn]h4M
} lt:&lIW,3
c!wRq4
JBJ?|}5k4c
public String getSSiteURL() u?MhK#Mr
{ Hf_ pe
return sSiteURL; C6a-
} 85[ 7lO)[
~Y*.cGA
Ank_;jo
public void setSSiteURL(String value) dz/fSA
{ Cu24xP`
sSiteURL = value; {fl[BX]kZ
} LK*9`dzv=G
`fX\pOk~e
g4Dck4^!4
public String getSFilePath() 2W_[|.;'
{ BCz4 s{F
return sFilePath; _eBNbO_J
} JLoE)\Mi
R[v<mo[s
L&:A59)1k
public void setSFilePath(String value) Vraz}JV
{ DO*6gzW
sFilePath = value; ^/%Y]d$
} W|rAn2H
*dBmb
w%)RX<h dI
public String getSFileName() PyHL`PZZ
{ V/"RCqY4
return sFileName; ;Wk3>\nT-
} 6]<yR> '
+`Nu0y!rj
C\BKdx5;
public void setSFileName(String value) #<m2Xo?d]
{ h;r^9g
sFileName = value; G,Eh8HboK
} F^!O\8PFd
l?J[K
g +gcH
public int getNSplitter() OiZ-y7;k^
{ '@#(jY0_
return nSplitter; ~-lUS0duh
} )c9Xp:
e<`?$tZ3
>Jn`RsuV
public void setNSplitter(int nCount) lnjs{`^
{ "10\y{`v^
nSplitter = nCount; )AdwA+-x
} UCj+V@{
} sIaehe'B
>Sk%78={R
,d_rK\J
/* G@jx&#v
**Utility.java 4Jc~I
*/ Bt$,=k
package NetFox; _<c}iZv@
.:Wp9M
`<<9A\Y-f
public class Utility { >>C S8
zlQBBm;fE
3%o}3.P,:@
public Utility() Lp|n)29+du
{ y,n.(?!*
-OD&x%L*{3
`#`C.:/n
} ..'"kX:5
eA Fp<2g
//线程睡眠 x]%,?Vd?
public static void sleep(int nSecond) Gkfzb>_V]
{ ~/aCzx~
try{ Oz]$zRu/0
Thread.sleep(nSecond); +CSR!
} M($GZ~ b%A
catch(Exception e) v6uRzFw
{ 0ZI}eZA j
e.printStackTrace (); zYdieE\-
} ,`a8@
} Em{;l:;(W
W}zq9|p
//日志 3bo [34
public static void log(String sMsg) jll|y0
{ ;KmrBNF
System.err.println(sMsg); (0_zp`)
} |{ZdAr.;
x*TJYST
k_?OEkgUh
public static void log(int sMsg) |lzcyz
{ a[}?!G-Wt|
System.err.println(sMsg); +`B^D
} En&gI`3n
} eBmHb\
RK$(
pTTM(Hrx
/* 7aPA+gA/
**TestMethod.java :h3U^
*/ {o*$|4q4
package NetFox; >MRuoJ
`}$bJCSF.n
Jx`7W1%T
public class TestMethod { +eLL)uk
L 9cXgd
mC0Dj O
public TestMethod() w6Mv%ZO_
{ ///xx/weblogic60b2_win.exe *a{WJbau]
try{ /!p}H'jl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f;,*P,K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :1gpbfW
SiteFileFetch fileFetch = new SiteFileFetch(bean); fWs*u[S
fileFetch.start(); Q4]Od{[
} N$:-q'hX
catch(Exception e){e.printStackTrace ();} JlRNJ#h>
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Y;g\ @j
} =kK%,Mr
'`W6U]7>
dShGIH?
public static void main(String[] args) D,=#SBJ:Z
{ UFj!7gX]
new TestMethod(); DeT$4c*:[
} ,TB$D]u8
} {/aHZ<I&^h
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