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)); ?l @=}WN
} ?uP5("c
for(int i=0;i<nEndPos.length-1;i++) e iH&<AH
{ '< >Q20
nEndPos = nStartPos[i+1]; I'n}6D.M
} U_Mag(^-
nEndPos[nEndPos.length-1] = nFileLength; -<T>paE9
} +Qzl-eN/+
} } 21!b :a
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bng/v
//启动子线程 /=#~8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &FZ~n?;hQ
for(int i=0;i<nStartPos.length;i++) ) R5[aO
{ &K=)YpT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,PKUgL}w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v-!Spf
nStartPos,nEndPos,i); <+%y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1`Bhis9X8
fileSplitterFetch.start(); }+u<w{-7/
} ,ag* /
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R Eo{E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ] ONmWo77o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .]<iRf[\[
nEndPos = " + nFileLength); c5KciTD^
// fileSplitterFetch[nPos.length-1].start(); JH2-'
Rf=-Q %
$|!3ks
//等待子线程结束 HG5E,^1n
//int count = 0; Pum&\.l
//是否结束while循环 Y~#.otBL&
boolean breakWhile = false; "18cD5-#
RR/?"d?&
F6+4Yy+
while(!bStop) *Kq;xM6Ck
{ 2`FDY3n
write_nPos(); PCc{0Rp\vk
Utility.sleep(500); D7B g!*
breakWhile = true; "1DlusmCCB
r=RiuxxTq
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for(int i=0;i<nStartPos.length;i++) Rp_}_hL0
{ 0Uk;&a0s
if(!fileSplitterFetch.bDownOver) l u{6
{ M4d4b
breakWhile = false; -"2%+S{
break; t|UM2h
} c,G[Rk
} VIod6Vk
if(breakWhile) oHV!>K_D
break; {p(6bsn_#]
NVf_#p"h
5GJa+St?
//count++; dg(sRTi{
//if(count>4) k$7Kz"
// siteStop(); Mt~2&$>
} <fgf L9-
J/Ch /Sa
THCvcU?X
System.err.println("文件下载结束！"); WE /1h
} 1wggYX
catch(Exception e){e.printStackTrace ();} C,<FV+r=^
} uCWBM
Je K0><
8ux
//获得文件长度 o7v9xm+
public long getFileSize() 73ABop
{ m^tf=O<
int nFileLength = -1; {~Q}{ha
try{ 2jxh7\zE
URL url = new URL(siteInfoBean.getSSiteURL()); bl|)/)6o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PvxU.
httpConnection.setRequestProperty("User-Agent","NetFox"); mMK 93Ng"&
qUQP.4Z95
'|&?$g(\h
int responseCode=httpConnection.getResponseCode(); og*ti!Z
if(responseCode>=400) >T\^dHtz
{ eFQz G+/
processErrorCode(responseCode); H]{`q
return -2; //-2 represent access is error )@.0ai
} OeQ~g-n
j#H&~f
O&dh<
String sHeader; W#x~x|(c
?,eq86-M
(S&D
for(int i=1;;i++) `cRRdD:dA
{ t6%zfm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R:44Gv7
//Utility.log(in.readLine()); qFY>/fCP4
sHeader=httpConnection.getHeaderFieldKey(i); {^R"V ,)
if(sHeader!=null) sA,2gbW
{ PiNf;b^9
if(sHeader.equals("Content-Length")) J$yJ2G
{ ?y~"\iP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k& ]I;Aq
break; S=`#X,Wo
} ~(.&nysZ-
} GM0pHmC
else tRTJQ
break; ;,@Fz
} YJZ`Clp?
} _J_QB]t
catch(IOException e){e.printStackTrace ();} L^ U.h
catch(Exception e){e.printStackTrace ();} aq^OzKP?
m9$lOk4/
% )}rQqQ
Utility.log(nFileLength); 4tp}
)u=a+T
/jn0Xh
return nFileLength; #b;TjnC5{$
} 19\ V@d^
Z4T{CwD`D
t8~isuiK
//保存下载信息（文件指针位置） `k9a$@Xg
private void write_nPos() )6U^!95
{ ,Q+.kAh !G
try{ 90a!_8o
output = new DataOutputStream(new FileOutputStream(tmpFile)); LH q~`
output.writeInt(nStartPos.length); @u-CR8^
for(int i=0;i<nStartPos.length;i++) D.w6/DxaXa
{ '=ydU+X
// output.writeLong(nPos); .fNLhyd
output.writeLong(fileSplitterFetch.nStartPos); U~8, N[
output.writeLong(fileSplitterFetch.nEndPos); #sf1,k5'
} Es1T{<G|w
output.close(); *HQ>tvUh
} zi+NQOhR
catch(IOException e){e.printStackTrace ();} edfb7prfTl
catch(Exception e){e.printStackTrace ();} mfgUf
} 7hKfxw-X@
SJ&+"S&
}Y3*X:i7
//读取保存的下载信息（文件指针位置） JuRx>F4
private void read_nPos() `t]8 [P5
{ AZbFj-^4
try{ %07vH&<C.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7@!3.u1B
int nCount = input.readInt(); D.x&N~-
nStartPos = new long[nCount]; @F!oRm5
nEndPos = new long[nCount]; _Q\<|~
for(int i=0;i<nStartPos.length;i++) Q.l3F3;
{ ?; tz
nStartPos = input.readLong(); WWVQJ{,}
nEndPos = input.readLong(); "'I|#dKoG
} rCdTn+O2
input.close(); %u*HNo
} G~zP&9N|
catch(IOException e){e.printStackTrace ();} )1Z @}o 9
catch(Exception e){e.printStackTrace ();} Vx=tP.BO]
} !/EN
n,b6|Y0
A7GWU{i
private void processErrorCode(int nErrorCode) E*#5OT
{ :gx]zxK
System.err.println("Error Code : " + nErrorCode); i [2bz+Z?
} >d^DN;p
dPF*G$
_#6*C%ax
//停止文件下载 6'1Lu1w
public void siteStop() R"O,2+@<.
{ '6f)^DYA'?
bStop = true; Zy^ wS1io
for(int i=0;i<nStartPos.length;i++) cbv%1DT3
fileSplitterFetch.splitterStop(); Ak,T{;rD
wl%I(Cw{]
B3&ETi5NTU
} S+-V16{i
} X->` ~-aj
//负责部分文件的抓取 dwUs[v
**FileSplitterFetch.java A=BT2j'l)
*/ Q6%Pp_$k
package NetFox; 8:"s3xaO3
md/NMC \
x UTlM
import java.io.*; ~{{@m]P
import java.net.*; C9nCSbGMY{
y:R+;91
Y?JB%%WWI
public class FileSplitterFetch extends Thread { ST[E$XL6
?2Sm f
W$Z8AZ{E
String sURL; //File URL Ca#T?HL
long nStartPos; //File Snippet Start Position &*o{-kw
long nEndPos; //File Snippet End Position Qsr+f~"W
int nThreadID; //Thread's ID (bGk=q=M
boolean bDownOver = false; //Downing is over NnO%D^P]
boolean bStop = false; //Stop identical u~1 ,88&U
FileAccessI fileAccessI = null; //File Access interface @6{F4
eZmwF@
;^ YpQP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }n?D#Pk,
{ 88A,ll%
this.sURL = sURL; q$jwH] .
this.nStartPos = nStart; Fz@U\\94z
this.nEndPos = nEnd; )S|&3\
nThreadID = id; #++D|oE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2:&QBwr+;
} [&:dPd1_
~5n?=
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public void run() E&> 2=$~
{ F&D,y-CQ
while(nStartPos < nEndPos && !bStop) Rh{`#dI~=
{ O2oF\E_6
8l>YpS*S^
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try{ G3.\x_;k
URL url = new URL(sURL); So}pA2[0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /=:Fw}vt
httpConnection.setRequestProperty("User-Agent","NetFox"); HnY.=_G
String sProperty = "bytes="+nStartPos+"-"; e@g=wN"@
httpConnection.setRequestProperty("RANGE",sProperty); !+n'0{
Utility.log(sProperty); O]Q8&(
M~g@y$
{R7m qzt
InputStream input = httpConnection.getInputStream(); N'I9J?e Q
//logResponseHead(httpConnection); IgKrcpK#}?
MN_1^T5
Q@cYHFi~+
byte[] b = new byte[1024]; #[y2nK3zF
int nRead; |5\: E}1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *):s**BJ$
{ Nd**":i$
nStartPos += fileAccessI.write(b,0,nRead); =Kt!+^\")
//if(nThreadID == 1) ;tfGhHpQn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -z>m]YDH
} SHqz&2u
Gc<^b
L:Me
Utility.log("Thread " + nThreadID + " is over!"); q`L}\}o
bDownOver = true; BJnysQ
//nPos = fileAccessI.write (b,0,nRead); z=qxZuFkDs
} rz5@E
catch(Exception e){e.printStackTrace ();} PH=O>a`a_O
} oX?~
} c)SQ@B@q
Q,R|VI6Co
M&0U@ r-
//打印回应的头信息 1c:/c|shQ_
public void logResponseHead(HttpURLConnection con) /B5rWJ2AS
{ +l>X Z
for(int i=1;;i++) e(jD[q
{ "_ON0._(/
String header=con.getHeaderFieldKey(i); Ob|v$C
if(header!=null) W ZW:q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EP6@5PNZ
Utility.log(header+" : "+con.getHeaderField(header)); KZ|p_{0&
else ^-s`$lTp
break; ,/UuXX
} ab*O7v
} UZu.B!4
u\=yY.
&&te(DC\
public void splitterStop() pwo @ S"
{ - 4B&{P
bStop = true; h]k1vp)Q y
} %wIb@km
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sh}eKwh
} 'HvJ]}p
GX%r-
T,v5cc:nO
/* G[Jz(/yNH
**FileAccess.java TGI`}#
*//文件访问(定位，写) q(}#{OO
package NetFox; M[^EHa<i
import java.io.*; ?1Uq ud
;i&t|5y~
y@dTdR2Wc
public class FileAccessI implements Serializable{ 9+:<RFJ
M|qJZ#{4>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {\ogw0X
RandomAccessFile oSavedFile; >C}KSyV;
long nPos; zq]:.s
d>x(Bj6
@|@6pXR.
public FileAccessI() throws IOException -p f9Wk
{ u$+nl~p[&
this("",0); NzbHg p
} MDfC%2Q
u{|^5%)
mlbSs_LT^
public FileAccessI(String sName,long nPos) throws IOException d&%}u1 .
{ 0Yfz?:e
oSavedFile = new RandomAccessFile(sName,"rw"); jYsg'Rl
this.nPos = nPos; u7bji>j
oSavedFile.seek(nPos); nLnzl
} kl#)0yqN0
oNRp
&p.7SPQ8/
public synchronized int write(byte[] b,int nStart,int nLen) 49dN~k=
{ VBe&of+
int n = -1; }1Pv6L(o)
try{ jW]Fx:mQi
oSavedFile.write(b,nStart,nLen); P.O/ZW>g
n = nLen; }K9Ji]tOK:
} 7OLchf
catch(IOException e) 8V+
{ ':|?M B
e.printStackTrace (); #v:A-u
} #YB3Ug]z
)!d_Td\-
hr/|Fn+kA
return n; OCI{)r<O2m
} 0Y/k/)Ul]
ou[Wz{
NucLf6
} . "`f~s\G
OZE.T-{
}62Q{>`
/* $"`e^J9!!
**SiteInfoBean.java c.h_&~0qf
*/ .,gVquqMY
package NetFox; P;p;o]
sW!MVv
$>=w<=r|;
public class SiteInfoBean { zWf(zxGAz
9v76A~~
mH!\]fmR~
private String sSiteURL; //Site's URL o.>Yj)U
private String sFilePath; //Saved File's Path =<z~OE'lV
private String sFileName; //Saved File's Name BHZSc(-o
private int nSplitter; //Count of Splited Downloading File I7jIA>ZZi
'jBtBFzP-
1:Xg&4s
public SiteInfoBean() !4mAZF b
{//nSplitter的缺省值为5 |@*
//default value of nSplitter is 5 UymhBh
this("","","",5); QjyJmW("Z
} jN2Xoh9
()yOK$"
<"x *ZT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Owm2/
{ +c\uBrlZQ;
sSiteURL= sURL; P!~B07y
sFilePath = sPath; jQ5FvuNOy
sFileName = sName; #5_pE1
this.nSplitter = nSpiltter; mJS-x-@
-|_io,eL;
Fo&ecWhw
} kud2O>>
J*]JH{
E1Rz<&L
public String getSSiteURL() 73(5.'F
{ ??XtN.]7
return sSiteURL; "gq_^&
} )LE#SGJP
_<l9j;6
@wW)#!Mou
public void setSSiteURL(String value) I}1<epd ,
{ }3y Q*<
sSiteURL = value; Ui;PmwQc&
} xwu,<M v`
UJGmaE
a8r+G]Z
public String getSFilePath() StM)lVeF
{ pqxBu
return sFilePath; DP4l %2m0
} 0/?=FM>
k{pn~)xg
nokMS
public void setSFilePath(String value) %{^kmlO
{ d15E$?ZLH
sFilePath = value; BG2Z'WOH
} @!s(Zkpev
BZ@v8y _TA
Wx-rW
public String getSFileName() ,ikn%l#cm
{ /BfCh(B
return sFileName; B,RHFlp{
} ~n!7 ?4%U
C~:!WRCz
iVb#X#
public void setSFileName(String value) wq`\p['Q,
{ p?eQN Y
sFileName = value; HZzdelo
} ,Y2){8#l
+0FmeM&`h_
6Pu5 k;H
public int getNSplitter() ' $X}'u
{ @)m+b;
return nSplitter; Q-Rt
} Q OP8{~O
O,!4 W\s
6'vt '9
public void setNSplitter(int nCount) ?kM53zbT#
{ `PvGfmYOl
nSplitter = nCount; T1pMe{
} }8&L?B;90
} O8S"B6?$~'
j8#B
>l|dLyiae
/* YfOO]{x,X
**Utility.java O{`r.H1',
*/ CF+:9PG
package NetFox; .=-K7.X.)
@X*r5hjc
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public class Utility { "M5&&\uT
Og3bV_,"
(_O_zu8_
public Utility() 9:jZ3U
{ mbRN W
B$cx '_zF
sy.U]QG
} NX4}o&mDwn
9b*1-1"
//线程睡眠 aj*%$!SU+
public static void sleep(int nSecond) zMQ|j_l9E
{ Qr l>A*
try{ _w>9Z>PR
Thread.sleep(nSecond); cYMlcwS
} :N([s(}!$2
catch(Exception e) 7A[`%.!F6
{ &-1;3+#w
e.printStackTrace (); y1:#0
} <sq@[\l}a
} 7lz"^
jNA^ (|:
//日志 d>qxaX;
public static void log(String sMsg) |);-{=.OdQ
{ ^~%zPlv
System.err.println(sMsg); Skd,=r
} 7`f',ZK%
y-c2tF@'v
&D 4Ci_6k
public static void log(int sMsg) _GK3]F0
{ kGSB6
System.err.println(sMsg); H:HJHd"W
} L'Fy\K\
} A_WtmG_9
&u/T,jy`
zWh[U'6
/* ]o]*&[C
**TestMethod.java cCH2=v4hU
*/ X%._:st
package NetFox; W+0VrH 0F
e-#!3j!'
7}<057Xn'
public class TestMethod { s$ 2@|;
*rk!`n&
Mo2b"A;}|
public TestMethod() s) vHLf4T
{ ///xx/weblogic60b2_win.exe |VL(#U
try{ IL]VY1'#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;9R;D,Gk!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Jh'\ nDz@e
SiteFileFetch fileFetch = new SiteFileFetch(bean); E5<}7Pt
fileFetch.start(); VfiMR%i}
} NN9`jP2
catch(Exception e){e.printStackTrace ();} H `V3oS~}
(fjAsbT
]7, mo
} 6DG:imGl
a9GLFA8Vq
Vnv9<=R
public static void main(String[] args) eiaLzI,O
{ {rG`Upp
new TestMethod(); [J|)DUjt
} THM\-abz
} 'MHbXFM
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