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)); DxD\o+:r
} z0x^HDAeC
for(int i=0;i<nEndPos.length-1;i++) vT MCZ+^g
{ ?^J%S,
nEndPos = nStartPos[i+1]; k%8kt4\wn6
} AQtOTT$
nEndPos[nEndPos.length-1] = nFileLength; j >`FZKxp
} TD-B\ @_
} +vH#xc\'
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-tx%#(?wH
//启动子线程 gV$0J?Pr.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q-A_8
for(int i=0;i<nStartPos.length;i++) -GCU6U|
{ WZjR^6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K47.zu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +K8T%GAr
nStartPos,nEndPos,i); eA3NyL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3''Uxlo\
fileSplitterFetch.start(); N"0>)tG
} *>!-t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d|`8\fq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @\:@_}Z`_}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /cVZ/"
nEndPos = " + nFileLength); ?=1i:h
// fileSplitterFetch[nPos.length-1].start(); OlptO60{ ]
asE.!g?
+ rM]RFi
//等待子线程结束 bdvpH DA
//int count = 0; ;mr*$Iu7|
//是否结束while循环 7<L!" 2VB
boolean breakWhile = false; _mQj=
D51s)?
-<AGCiLz
while(!bStop) aI|X~b
{ Ef@)y&hn
write_nPos(); VV#'d
Utility.sleep(500); #Uep|A
breakWhile = true; 7Bd=K=3u
}jP/XO1f
IL uQf-
for(int i=0;i<nStartPos.length;i++) Lo Y*,Aa&
{ +.rE|)BPy
if(!fileSplitterFetch.bDownOver) (]VY==t~
{ |VjD. ]I
breakWhile = false; 90-s@a3B-j
break; ;TK$?hrv*1
} C1qlB8(Wh>
} |N3#of(
if(breakWhile) hSN38wy
break; *.VNyay
~]9EhC'l
0QW;=@)d
//count++; Ls3r( Tf
//if(count>4) rJB/)4 mE
// siteStop(); +D[C.is>]}
} I>6zX
obv_?i1
L)S V?FBx
System.err.println("文件下载结束！"); +tG'
} <(xro/
catch(Exception e){e.printStackTrace ();} r^ '
} '$z@40u
Z Y5Pf 1
79k+R9m
//获得文件长度 +1\t0P24
public long getFileSize() ,% .)mf
{ _Kh8 <$h
int nFileLength = -1; -q nOq[
try{ 5yj6MaqJ
URL url = new URL(siteInfoBean.getSSiteURL()); r;>.*60AT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &IsPqO
httpConnection.setRequestProperty("User-Agent","NetFox"); H:WuMwD4
u?>8`]r
>66 `hZ
int responseCode=httpConnection.getResponseCode(); FF|M7/[~
if(responseCode>=400) w6-<HPW<S
{ r]aI=w<(f
processErrorCode(responseCode); ",Fvv
return -2; //-2 represent access is error uU-1;m#N?
} -[h|*G.J
qd~9uo&[Ig
YOA)paq+
String sHeader; g;7u-nP
_kBx2>qQ
R+=wSG]
for(int i=1;;i++) xX Dj4j,
{ yb0Mn*X+ N
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e nw*[D !
//Utility.log(in.readLine()); {K:]dO
sHeader=httpConnection.getHeaderFieldKey(i); e+<9Sh7&
if(sHeader!=null) FMWM:
{ Lzcea+*uw
if(sHeader.equals("Content-Length")) a(G}<
{ wLvM<p7OX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M~+DxnJ=
break; hZ"Sqm]
} !;${2Q
} 9kbczL^Y
else ,rNud]NM8
break; 2lqy<o
} F6>oGmLy
} ~)6EH`-
catch(IOException e){e.printStackTrace ();} 7")~JBH
catch(Exception e){e.printStackTrace ();} +wI<w|!
E@AV?@<sc
,K|UUosS-#
Utility.log(nFileLength); n8`WU3&
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^ohIJcI-
return nFileLength; 1y,/|Y
} . lNf.x#u
uH[:R vC0
o%0To{MAF-
//保存下载信息（文件指针位置） rZ2cC#
private void write_nPos() P?zaut
{ :H+8E5
try{ ,,BWWFg~
output = new DataOutputStream(new FileOutputStream(tmpFile)); zJ@^Bw;A^@
output.writeInt(nStartPos.length); "b%FkD
for(int i=0;i<nStartPos.length;i++) Z9Z\2t
{ BO%'/2eV
// output.writeLong(nPos); (%"9LYv
output.writeLong(fileSplitterFetch.nStartPos); c%1{l]
output.writeLong(fileSplitterFetch.nEndPos); DKkilqVM
} z\woTL6D]
output.close(); wN :"(mQ
} 9Hd_sNUu\
catch(IOException e){e.printStackTrace ();} yqB!0) <
catch(Exception e){e.printStackTrace ();} ydAiH*>
} 2(m#WK7>F
jx2{kK
l[rK)PM
//读取保存的下载信息（文件指针位置） qB&Je$_uh
private void read_nPos() |.L_c"Bc
{ C7DwA/$D
try{ Rz[3cN)?q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i83[':
int nCount = input.readInt(); ml /S|`Drk
nStartPos = new long[nCount]; 1l Cr?
nEndPos = new long[nCount]; &~2IFp
for(int i=0;i<nStartPos.length;i++) +'nMy"j1
{ bZ``*{I/
nStartPos = input.readLong(); C\B4Uu6q
nEndPos = input.readLong(); 4u"Bll
} k+vfZ9bD(J
input.close(); NRgVNE
} 8@RtL,[d
catch(IOException e){e.printStackTrace ();} 3dSC`K
catch(Exception e){e.printStackTrace ();} a6 1!j>Kx
} tw&v@HUP
* ^V?u
9%1J..c
private void processErrorCode(int nErrorCode) , 2xv
{ '4Fwh]Ee
System.err.println("Error Code : " + nErrorCode); ?~!9\dek,
} e<[ ] W4"A
v+8Ybq
>P&1or)e%
//停止文件下载 ra>2<
public void siteStop() -V;BkE76
{ NzTF2ve(
bStop = true; RZ;s_16GQ
for(int i=0;i<nStartPos.length;i++) c?u*,d) G
fileSplitterFetch.splitterStop(); 44|tCB`
/ *PHX@
6bLn8UT
} Pg{1'-
} {]Hv*{ ]
//负责部分文件的抓取 Bc[~'gn
**FileSplitterFetch.java u3GBAjPsIk
*/ nosD1sS.K8
package NetFox; :GO"bsjL
6a9$VGInU
(xRcG+3];
import java.io.*; 7.6L1srV
import java.net.*; x3Y)l1gh
kS:#|yY8%
c38XM]Jeq
public class FileSplitterFetch extends Thread { stBe ^C
VqpC@C$
~~ rR< re
String sURL; //File URL >3Q|k{97
long nStartPos; //File Snippet Start Position #mA(x@:*
long nEndPos; //File Snippet End Position /:'>-253
int nThreadID; //Thread's ID vIbM@Y4 '?
boolean bDownOver = false; //Downing is over qS FtQ4
boolean bStop = false; //Stop identical 9;?u%
FileAccessI fileAccessI = null; //File Access interface KP>9hEh
=@?[.`
S!.&#sc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h0@a"DqK
{ eY5mwJ0K
this.sURL = sURL; |f#hGk6
this.nStartPos = nStart; ,7]hjf_h
this.nEndPos = nEnd; yy7(')wKO
nThreadID = id; '=n?^EPE3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e12QYoh
} '#Au~5
_wS=*-fT
r~j [Qm"CJ
public void run() 0)332}Oh
{ dD=$$( je
while(nStartPos < nEndPos && !bStop) bj`\;_oo
{ VNHceH
0lg$zi x(
cR/Nl pX
try{ !i^"3!.l,]
URL url = new URL(sURL); ,=P&{38\q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VAz4@r7hkq
httpConnection.setRequestProperty("User-Agent","NetFox"); a(~Y:v
String sProperty = "bytes="+nStartPos+"-"; 3SP";3+
httpConnection.setRequestProperty("RANGE",sProperty); <46&R[17M
Utility.log(sProperty); ~v.mbh
fRQ,Z
"w'pIUQ3,
InputStream input = httpConnection.getInputStream(); ,X4+i8Yc
//logResponseHead(httpConnection); si]VM_w6
3' i6<
i[!|0U`p
byte[] b = new byte[1024]; o utJ/~9;
int nRead; ,Vhve'=*2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s5nw<V9$]
{ 9&n9J^3L
nStartPos += fileAccessI.write(b,0,nRead); ES~b f
//if(nThreadID == 1) .h-mFcjy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ga5Q
} cag5w~Px
da7"Q{f+
79v+ze
Utility.log("Thread " + nThreadID + " is over!"); gyw=1q+
bDownOver = true; NPT-d
//nPos = fileAccessI.write (b,0,nRead); HAxLYun(3w
} k$3pmy*
catch(Exception e){e.printStackTrace ();} i1vz{Tc
} :y-;V
} # )y`Zz{h
Qn*l,Z]US
4=L>
//打印回应的头信息 jIubJQR~
public void logResponseHead(HttpURLConnection con) EN!C5/M{&
{ .l1x~(
for(int i=1;;i++) \f9WpAY
{ IVNH.g'
String header=con.getHeaderFieldKey(i); sgfqIe1
if(header!=null) rmX*s}B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I%5vI}
Utility.log(header+" : "+con.getHeaderField(header)); ~ WWhCRq
else OcTWq
break; |Ea%nghl
} qLEYBv-3
} CvU$Fsb
ET}Z>vU}+
jY=y<R_oK
public void splitterStop() ?Q"andf
{ n _K1%
bStop = true; vB7Gx>BQd
} c]4X`3]
4Zbn8GpC
hxoajexU
} w+)${|N?
^~~Rto)Y
sX1DbEjj[o
/* $JY\q2
**FileAccess.java 50_[hC&C)
*//文件访问(定位，写) rfwJLl/
package NetFox; :nIMZRJ_!E
import java.io.*; ;fNCbyg4 I
$g>bp<9v4
vb>F)X?b_
public class FileAccessI implements Serializable{ )L b` 4B
`%Ih'(ne
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b}qfOgd5
RandomAccessFile oSavedFile; apL$`{>US
long nPos; rH7Cv/Y
:!aLa}`@
fpf]qQ W~7
public FileAccessI() throws IOException nah?V" ?Y
{ :E")Zw&sW3
this("",0); EE"8s7ZF
} 1V2]@VQF
7!J-/#!
c+FTt(\8.
public FileAccessI(String sName,long nPos) throws IOException [cB^6v
{ %6Gg&Y$j!
oSavedFile = new RandomAccessFile(sName,"rw"); NJBSVCb
this.nPos = nPos; Tt: (l/1
oSavedFile.seek(nPos); KdoI
} 'l'3&.{Yfk
d|R-K7 ~~
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public synchronized int write(byte[] b,int nStart,int nLen) #zsaQg, B
{ &{j!!LL
int n = -1; &2W"4SE]6
try{ F(VVb(\jd
oSavedFile.write(b,nStart,nLen); #da{3>z:
n = nLen; %Y~"Stmx
} t'2A)S
catch(IOException e) iy~h|YK;
{ }.g5zy
e.printStackTrace (); Z )c\B
} ^SpQtW118
zQ+Mu^|u+
cX9o'e:C
return n; Hhtl~2t!0
} 4. R(`#f
336ETrG^0
h\!8*e;RAW
} j sPavY
_*H Hdd5I
aL:|Dr3SX
/* xN*k&!1&
**SiteInfoBean.java 1 iox0
*/ J$6WUz:?
package NetFox; Rrh6-]A
*6yY>LW
6>]
public class SiteInfoBean { NFTv4$5d
/xUF@%rT
aV$kxzEc
private String sSiteURL; //Site's URL brmSJ7
private String sFilePath; //Saved File's Path L;0 NR(b!
private String sFileName; //Saved File's Name !L.R"8!
private int nSplitter; //Count of Splited Downloading File |tAkv
kTH""h{
__b4dv
public SiteInfoBean() 8gavcsVE[
{//nSplitter的缺省值为5 %%K3J<5
//default value of nSplitter is 5 t]SB.ja
this("","","",5); Z}t;:yhR
} :;_}Gxx
#HV5M1mb
rCF=m]1zxT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +rv##Z
{ ,< g%}P/
sSiteURL= sURL; 3:GwX4yW
sFilePath = sPath; |fKT@2(
sFileName = sName; Stwg[K0<
this.nSplitter = nSpiltter; x_~_/&X5
Ug+ K:YUq
x'0_lf</#
} q;#AlquY@
F^/KD<cgK
'o)Y!VYnJF
public String getSSiteURL() s[8M$YBf
{ [s$x"Ex
return sSiteURL; (-$5YKm
} [z"E"_r~%Y
LBq2({="
'yVe&5?
public void setSSiteURL(String value) VHPqEaR
{ m!KEK\5M?
sSiteURL = value; ^1~lnD~0
} ?GH/W#{o)
3ibQbk
LCSvw
public String getSFilePath() G>"n6v'^d
{ :rM2G@{
return sFilePath; l@&-be
} "8%$,rG1&
YCE *Dm
_`p-^I
public void setSFilePath(String value) $(gL#"T
{ +%j27~R>D
sFilePath = value; `D|])^"{
} vv&< 7[
p@O Ip
QDW,e]A
public String getSFileName() &[{sA;
{ k={1zl ;
return sFileName; V'#R1x"3
} x%`YV):*
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"Y^j=?1k
public void setSFileName(String value) ##BbR
{ . q -:3b
sFileName = value; zWU]4;,"
} VoYL}67c
9[JUJ,#X'0
"f 89
public int getNSplitter() ?\8
{ QY4;qA
return nSplitter; 7b08Lo7b
} UapU:>!"`
5?HwM[`
B-_b.4ND)
public void setNSplitter(int nCount) c_ncx|dUs
{ )V~=B]
nSplitter = nCount; 5-GS@fY
} y+k^CT/u
} Bk3\NPa
6QA`u*
`B"sy8}x
/* BFw_T3}zn
**Utility.java $365VTh"
*/ i,^3aZwJ'
package NetFox; UH6 7<_mK
czIAx1R9
\~A qA!)6
public class Utility { \8$~ i
^?H|RAp
>w<w*pC
public Utility() 17?YN<
{ iii|;v]+
UA*VqK)Y
vTx>z\7q,
} 2<B'PR-??y
v.<mrI#?
//线程睡眠 FfM^2`xP
public static void sleep(int nSecond) .,z6a
{ {aUTTEu
try{ -GFZFi
Thread.sleep(nSecond); v]{UH{6
} CR'%=N04^
catch(Exception e) qJ`:$U
{ \\\8{jq
e.printStackTrace (); B2j1GJEO
} f0SrPc v
} D {Ol8:
O%kUj&h^
//日志 hm73Zy
public static void log(String sMsg) \t=0rFV)t
{ ="YGR:
System.err.println(sMsg); rWL;pM<
} {>1FZsR49t
exhU!p8
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public static void log(int sMsg) T#-;>@a}
{ I)'bf/6?
System.err.println(sMsg); a)ry}E =f
} IyHbl_P ^
} Oq.ss!/z
Oh$:qu7o0&
c$ZVvu
/* PX|@D_%Y=
**TestMethod.java G~<UP(G
*/ RX>P-vp
package NetFox; }?9&xVh?\
ffmtTJFC5
&t9V
public class TestMethod { >E<ib[vK[
r+Ki`HD%
.^{%hc*w4
public TestMethod() ;Z{D@g+
{ ///xx/weblogic60b2_win.exe nFn!6,>E
try{ -Ty~lZ)TDT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lNL=Yu2p_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :_R:>n9 p
SiteFileFetch fileFetch = new SiteFileFetch(bean); (*$bTI/~
fileFetch.start(); qazA,|L!
} h`|04Q
catch(Exception e){e.printStackTrace ();} xrkl)7;
?+d`_/IB
\2s`mCY
} bGWfMu=n
Eu?z!
f(5(V %
public static void main(String[] args) U7s$';y"%
{ |GnTRahV.
new TestMethod(); !y_{mE?V(
} 4 ThFC
} NGc~%0n
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