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)); Rk=B;
} C[pDPx,#:G
for(int i=0;i<nEndPos.length-1;i++) s_[?(Ip{
{ Iu[EUi!"
nEndPos = nStartPos[i+1]; Mm;)O'XDE
} pE<' '`
nEndPos[nEndPos.length-1] = nFileLength; !eq]V9
} Yru[{h8hw`
} xpxm9ySwu
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4_Jdh48-d
//启动子线程 OS 6 )`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -Gpj^aBU
for(int i=0;i<nStartPos.length;i++) @CmxH(-i-
{ ?MYD}`Cv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a#IJ<^[8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GEA;9TU|V
nStartPos,nEndPos,i); v(^rq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i/~J0qQ
fileSplitterFetch.start(); t>fB@xHBB
} MH?B.2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T42g4j/l~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _:L*{=N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J]0#M:w&
nEndPos = " + nFileLength); =/;_7|ssd
// fileSplitterFetch[nPos.length-1].start(); *LRGfk+h
yjq )}y,tF
nf4P2<L!
//等待子线程结束 IMZKlU3
//int count = 0; 'dzp@-\
//是否结束while循环 L@Z &v'A
boolean breakWhile = false; 4.'EEuRw\}
+ LwoBn>6
D$cMPFa2Nt
while(!bStop) *ls6#j@
{ bwJi[xF
write_nPos(); WGmCQE[/c
Utility.sleep(500); eFQi K6`i
breakWhile = true; 4Le5Ms/
Z|c9%.,
Lvq]SzOw
for(int i=0;i<nStartPos.length;i++) FQFENq''B
{ ej;taKzj
if(!fileSplitterFetch.bDownOver) pJz8e&wyLM
{ {yHfE,
breakWhile = false; o0'av+e7
break; \bOjb\ w$
} fhmr*E'J
} -z$0S%2?
if(breakWhile) .;b> T
break; uKy*N*}
=T)2wcXBB
lt4jnV2"a
//count++; fn OkH
//if(count>4) d_uy;-3
// siteStop(); *u/|NU&X
} wIF ":'
!5j3gr~
>~rd5xlk
System.err.println("文件下载结束！"); 1Q SIZoK7
} yU"G|Ex
catch(Exception e){e.printStackTrace ();} *fSM'q;
} %j">&U.[
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jtv Q<4
//获得文件长度 ogqV]36Idh
public long getFileSize() wsrx|n[]
{ V|\A?
int nFileLength = -1; dV{Hn {(
try{ DA$Q-
URL url = new URL(siteInfoBean.getSSiteURL()); ^Nw]'e3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jche79B
httpConnection.setRequestProperty("User-Agent","NetFox"); o%%x'uC
=h::VB}Lv
&ZN'Ey?
int responseCode=httpConnection.getResponseCode(); 0:'jU
if(responseCode>=400) >iH).:j
{ zm+4Rl(
processErrorCode(responseCode); ]B3FTqR{i
return -2; //-2 represent access is error Qz+d[%Q}x
} 9*;isMkq<
;jU-<
-]\E}Ti
String sHeader; m5w9l"U]H
9K46>_TyH
kA%OF*%|6
for(int i=1;;i++) s2?,'es
{ `B\KS*Gya#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R+K&<Rz
//Utility.log(in.readLine()); x}<G!*3
sHeader=httpConnection.getHeaderFieldKey(i); o:8S$F`O@
if(sHeader!=null) n>:c}QAJH
{ 8EG8!,\I
if(sHeader.equals("Content-Length")) d Zz^9:C+
{ 9/daRq$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qM>OE8c#/
break; {Okik}Oh
} o+-Ge J
} >|/? Up
else udD*E~1q
break; 7G[ GHc>
} 7e4tUAiuU
} SKSAriS~
catch(IOException e){e.printStackTrace ();} ~5 pC$SC6>
catch(Exception e){e.printStackTrace ();} #/t>}lc
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z]l-?>Zbg
Utility.log(nFileLength); 1gShV ]2
o\ow{gh9
,eeL5V
return nFileLength; +%}5{lu_e
} CDW(qq-zD
EB2^]?
[wio/wc
//保存下载信息（文件指针位置） 3TiXYH
private void write_nPos() 7 Mki?EG
{ K;y\[2;}e,
try{ J4Z<Yt/
output = new DataOutputStream(new FileOutputStream(tmpFile)); k[ffs}
output.writeInt(nStartPos.length); :qCm71*
for(int i=0;i<nStartPos.length;i++) M,\|V3s
{ )/WA)fWkT
// output.writeLong(nPos); _UBJPb@=U
output.writeLong(fileSplitterFetch.nStartPos); $qlqWy-s
output.writeLong(fileSplitterFetch.nEndPos); p=-B~:
} F*4Qa
output.close(); bpF@}#fT
} |T$a+lHMD
catch(IOException e){e.printStackTrace ();} /[|}rqX(
catch(Exception e){e.printStackTrace ();} GATP
} )|Vg/S
;%rs{XO9
oX2DFgz
//读取保存的下载信息（文件指针位置） oj^5G ]_<
private void read_nPos() KSgQ:_u4}
{ X[~f:E[1J
try{ [2QY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N}+B:l]Qy
int nCount = input.readInt(); K*Nb_|~
nStartPos = new long[nCount]; `z$uw
nEndPos = new long[nCount]; v;bM.OL
for(int i=0;i<nStartPos.length;i++) -Ty<9(~S
{ qN1e{T8u
nStartPos = input.readLong(); \9>g;qPg}
nEndPos = input.readLong(); #>E3'5b
} J"D&q
input.close(); nXM9Px!
} lNh=>DPu
catch(IOException e){e.printStackTrace ();} ]*g ss'N
catch(Exception e){e.printStackTrace ();} (iCZz{l@~
} Nn,vdu{^2
K{=r.W
UPVO~hB;
private void processErrorCode(int nErrorCode) '#McY'.D T
{ iO?gF
System.err.println("Error Code : " + nErrorCode); c+E//X|
} 0i`v:Lq%
Y uw E 0
2pxWv )0
//停止文件下载 F;?TR[4!k
public void siteStop() (EOec5qXU
{ Lt;.Nw
bStop = true; ~4=]%XYz
for(int i=0;i<nStartPos.length;i++) ,<;l"v(
fileSplitterFetch.splitterStop(); M5T=Fj86
:\1rQT
2\nBqCxR
} (:&&;]sI
} X|-v0 f
//负责部分文件的抓取 |i}+t
**FileSplitterFetch.java >tmnj/=&
*/ S<y>Y
package NetFox; I5TQ>WJbf
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'FPcAW^8
import java.io.*; 45r]wT(C
import java.net.*; vu_>U({. T
=A0"0D{\
=9DhO7I'
public class FileSplitterFetch extends Thread { uS: A4tN
nxn[ ~~
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String sURL; //File URL .*RB~c t
long nStartPos; //File Snippet Start Position F1?CqN M
long nEndPos; //File Snippet End Position Ks49$w<
int nThreadID; //Thread's ID d$"G1u~%
boolean bDownOver = false; //Downing is over .KiPNTh'
boolean bStop = false; //Stop identical B%%.@[o,
FileAccessI fileAccessI = null; //File Access interface <?>I\
ny!lja5[
:Bx+WW&P.i
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dDv{9D,
{ B&%L`v2[
this.sURL = sURL; RQj`9F
this.nStartPos = nStart; ";-{~
this.nEndPos = nEnd; */%$6s~
nThreadID = id; YiIddQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sW]yuu!/
} %Lh-aP{[e
wE,=%?"
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public void run() 2cs?("8e%
{ aJK-O"0/
while(nStartPos < nEndPos && !bStop) c{'$=lR "
{ ys&"r":I
LCo1{wi
Ht`<XbQ>
try{ /32Ta
URL url = new URL(sURL); '|YtNhWZ?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lF;ziF
httpConnection.setRequestProperty("User-Agent","NetFox"); 4)z3X\u|Z2
String sProperty = "bytes="+nStartPos+"-"; T8,k77
httpConnection.setRequestProperty("RANGE",sProperty); ALE808;|
Utility.log(sProperty); D:YN_J"kV
l1-4n*fU
pTa'.m
InputStream input = httpConnection.getInputStream(); \b_-mnN"
//logResponseHead(httpConnection); otWo^CE$
a^RZsR
) >>u|#@z
byte[] b = new byte[1024]; 92P,:2`a
int nRead; VRtbHam
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &%|xc{i
{ i;[h 9=\/
nStartPos += fileAccessI.write(b,0,nRead); x\Nhix}1D
//if(nThreadID == 1) D 7Gd%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c^ixdk
} &_Cxv8
x><zGXvvp|
bajC-5R1k
Utility.log("Thread " + nThreadID + " is over!"); _N>wzkJ
bDownOver = true; kN'|,eKH4
//nPos = fileAccessI.write (b,0,nRead); w;N{>)hv
} LFEp
catch(Exception e){e.printStackTrace ();} /`7 IK
} E0sbU<11
} &GXtdO>;Zv
pj!k|F9
W@:^aH
//打印回应的头信息 ]h #WkcXQ
public void logResponseHead(HttpURLConnection con) GIl:3iB49
{ |RHO+J
for(int i=1;;i++) H/cs_i
{ |x1$b7
String header=con.getHeaderFieldKey(i); QDIsC
if(header!=null) xT{TVHdU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y,'FTP9?
Utility.log(header+" : "+con.getHeaderField(header)); <h'8w
else #Y;.>mF
break; %3]3r*e&5
} Sp<hai
} !&@2
1P5*wNF
~GNyE*t/Y
public void splitterStop() GYFgEg}
{ -(6eVI
bStop = true; .[edln
} pO\S#GnX
o&CghF
b cC\
} Ro$j1Aw(
X32RZ9y
I'x$,s
/* Q<z)q<e
**FileAccess.java * zd.
*//文件访问(定位，写) a^@+%?X
package NetFox; 5?^]1P_
import java.io.*; 0w^jls
I|$'Q$m~
{]+ jL1
public class FileAccessI implements Serializable{ TAXd,z N
F?!FD>L{`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 BfX%|CWh
RandomAccessFile oSavedFile; Z$Z`@&U=
long nPos; 2}D,df'W4
].LJt['%8
f&K}IM8& #
public FileAccessI() throws IOException Q]!6uA$A
{ !.9l4@z#
this("",0); 5r'=O2AZX
} Sq?,C&LsA
EJO.'vQ
g* %bzfk=|
public FileAccessI(String sName,long nPos) throws IOException Y3D3.T6Q
{ D5=C^`$2
oSavedFile = new RandomAccessFile(sName,"rw"); fW(;
this.nPos = nPos; *zJD$+Fo
oSavedFile.seek(nPos); #]"/{Z
} 1Pu ,:Jt
DKR<W.!*t
OdO{xG G@
public synchronized int write(byte[] b,int nStart,int nLen) {PL,VY)Z
{ BeAk21xb
int n = -1; 7^HpVcSM
try{ rZ pbu>S
oSavedFile.write(b,nStart,nLen); C=8H)Ef,l
n = nLen; cvxIp#FbW
} QT_Srw@
catch(IOException e) L+_8QK<
{ ^n t~-%
e.printStackTrace (); Xz8$Xz,O
} {>S4#^@}
ldP3n:7FS
[qSQ#Qzi2i
return n; :g&>D#{
} GX7VlI[
m{VL\ g)
R j-jAH
} m^z,,t9
/;+oz
5Lw{0uLr
/* 0"hiCGm'
**SiteInfoBean.java Ec+22X
*/ ?.8<-
package NetFox; DQcWq'yY^
0(\p<qq
ohtT O]\
public class SiteInfoBean { D^$]>-^
S=4R5igrC
V_jiOT!
private String sSiteURL; //Site's URL ,dOMW+{
private String sFilePath; //Saved File's Path vXc!Zg~
private String sFileName; //Saved File's Name /=bSt
private int nSplitter; //Count of Splited Downloading File cY{I:MA+h@
t`uc3ta"9
wtq,`'B
public SiteInfoBean() }lH;[+u3
{//nSplitter的缺省值为5 R3cg2H
//default value of nSplitter is 5 +9TV:T
this("","","",5); CDJ$hu
} Il|GCj*N
^[0"vtb
(Bsw/wv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) STw oYn
{ bea|?lK
sSiteURL= sURL; }N@n{bu+
sFilePath = sPath; f KHse$?_
sFileName = sName; M'YJ"
this.nSplitter = nSpiltter; $%B5$+
_n7%df
<H!O:Mf_p
} ~bWhth2*
JXL'\De ;
m!;G/s*
public String getSSiteURL() >n(F4C-pl
{ TFYw
return sSiteURL; t]4!{~,
} S3QaYq"v
1}`2\3,
rJX\6{V!_
public void setSSiteURL(String value) 'bl%Y).9w
{ lz- iCZ
sSiteURL = value; w\p9J0
} NfOp=X?Y
RFB(d=o5S
*G\=i A
public String getSFilePath() >C:If0S4X
{ X`D+jiQ(f
return sFilePath; p x0Sy|
} Nvhy3
=88t*dH(,"
3Mur*tj#
public void setSFilePath(String value) 0juDuE?
{ (V8?,G>
sFilePath = value; %TDXF_.[
} J,9%%S8/C
]b> pI;
1b8c67j[
public String getSFileName() wz h.$?~
{ - {0g#G
return sFileName; 4Mi~1iZj
} ;sCU[4
U[bgu#P;
0_Lm#fE U
public void setSFileName(String value) zs0hXxTY:
{ G8noQ_-
sFileName = value; 2Sjt=LOc="
} ">cqt>2 A
ZzT&$J7]`{
=E!x~S;N
public int getNSplitter() a&N%|b K
{ tq0;^L
return nSplitter; I=o'+>az
} jx'2N~$
V'C-'Ythwf
vcwK6G
public void setNSplitter(int nCount) HZ{n&iJ
{ ,2ME2@OP
nSplitter = nCount; H@Q`
} puA|NT
} cFDxjX?~
8!;$qVt
|UYED%dC
/* Ox~ 9_d
**Utility.java l0. FiO@_Q
*/ #3.\j"b
package NetFox; z(rK^RT
rpSr^slr
l^ Rm0t_
public class Utility { JCNk\@0i*
l1|~
qfa}3k8et
public Utility() ~o i)Lf1
{ l0:5q?g
j3{HkcjJG
mTJ"l(,3
} jFG5)t<D
EavX8r
//线程睡眠 S*xhX1yUi
public static void sleep(int nSecond) @UV{:]f~e
{ BKX9SL]
try{ xG8`'SNY
Thread.sleep(nSecond); 0U%Xm[:
} *%I[ ke *
catch(Exception e) 4~Dax)
{ UUH;L
e.printStackTrace (); fx]eDA|$e
} nc&Jmo7
} HA1]M`&
O)1E$#~
//日志 S+iP^*L,c
public static void log(String sMsg) $o"g73`3
{ <}]{~y
System.err.println(sMsg); C38%H
} /K@$#x_{
.yX>.>"T|
eG4>d^`c
public static void log(int sMsg) rFfy#e
{ D'nL
System.err.println(sMsg); ?&xlT+JM
} !)nD xM`p
} I-bF{
M/} aq
R:f7LRF/\
/* -%H%m`wD
**TestMethod.java [IMQIX
*/ 'bPk'pj9
package NetFox; wFb@1ae\
2f^-~dz
m!:.>y
public class TestMethod { -bm,:Iy!
}PZ=`w*O
_ eiF@G
public TestMethod() 8%-%AWF]
{ ///xx/weblogic60b2_win.exe ,VWGq@o%
try{ #%8 w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %Hwbw],kl8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !k-` eJ|
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5VKcV&D
fileFetch.start(); A0>x9XSkJ
} > H~6NBd5D
catch(Exception e){e.printStackTrace ();} . ,R4WA,
m8HYWzN
A9;0y jae
} u7#z^r
Y"*:&E2)r
LABNj{=D!
public static void main(String[] args) "{ FoA3g|
{ a_{6Qdl
new TestMethod(); i-.c=M
} mW +tV1XjG
} lhxdx
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