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)); Rw<O%i5/d
} .7+"KP:
for(int i=0;i<nEndPos.length-1;i++) ~wu\j][2
{ !Ld[`d.|R!
nEndPos = nStartPos[i+1]; },;Z<(
} [M#(su0fv
nEndPos[nEndPos.length-1] = nFileLength; )=!|^M
} y,6KU$G
} >x]ir
~"Su2{"8B
L/)eNZ
//启动子线程 N+vsQ!Qz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z2jS(N?J1
for(int i=0;i<nStartPos.length;i++) sT,*<^
{ od^o9(.W^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iM$iZ;Tp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k&:~l@?O
nStartPos,nEndPos,i); @W=:r/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I5]58Ohx
fileSplitterFetch.start(); Qnx?5R-}ZU
} }+giQw4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;<=z^1X9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1I%niQv5t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L+lX$k
nEndPos = " + nFileLength); HP=5a.
// fileSplitterFetch[nPos.length-1].start(); YXg^t$
)"g @"LJ=
?z3|^oU~d
//等待子线程结束 U^Iq]L
//int count = 0; t1p[!53(
//是否结束while循环 CQA^"Ll
boolean breakWhile = false; Hn]6re
ItE)h[86
D77$aCt
while(!bStop) P)[QC
{ ^vZu[m
write_nPos(); (hIe!"s*
Utility.sleep(500); aN';_tGvK
breakWhile = true; lr[&*v?h
gu1n0N`b
(\4YBaGd
for(int i=0;i<nStartPos.length;i++) \*#E4`Y
{ &-KQ m20n
if(!fileSplitterFetch.bDownOver) `a8&7J(
{ 91ec^g
breakWhile = false; y(j vl|z[
break; ,w,)n^
} +$R%Vbd
} }7i}dyQv}
if(breakWhile) JY9hD;`6y
break; d3p;[;`
D7C%Y^K]>E
zc1~q
//count++; f.RwV+lq
//if(count>4) 787}s`,}
// siteStop(); { /Gm|*e{
} W|6.gN]
GFZx[*+%%z
bQwiJ`B&
System.err.println("文件下载结束！"); RohD.`D
} 7mYBxE/
catch(Exception e){e.printStackTrace ();} ROj=XM:+
} J!:v`gb#@A
h)T-7b
F5<GGEQb
//获得文件长度 _p| KaT``
public long getFileSize() gWy2E;"a
{ [jF\"#A
int nFileLength = -1; :#p!&Fi
try{ 4kQL\Ld#E%
URL url = new URL(siteInfoBean.getSSiteURL()); '^.}5be&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %Tv^BYQAZ
httpConnection.setRequestProperty("User-Agent","NetFox"); ^k}jPc6
@y`7csbp
<ba+7CK]w
int responseCode=httpConnection.getResponseCode(); -* ;`~5
if(responseCode>=400) qbe9 CF'@_
{ YNi3oG]h
processErrorCode(responseCode); nLjo3yvV..
return -2; //-2 represent access is error tvG/oe .1'
} e#$ZOK)`
ocT.2/~d
1~#p3)B
String sHeader; }nJG<rY
oXkxd3
hkL[hD
for(int i=1;;i++) yjP;o`z%
{ vMOit,{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f i3<
//Utility.log(in.readLine()); Zj8aD-1]U^
sHeader=httpConnection.getHeaderFieldKey(i); eqze7EY
if(sHeader!=null) yegTKoY
{ <ctn_"p Z
if(sHeader.equals("Content-Length")) KD7RI3'?
{ Y+tXWN"8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W@x UR-}51
break; O5Xu(q5+
} |0mVK`
} }GCt)i_
else f9g#pyH4
break; 0VB~4NNR
} /*bS~7f1
} 98os4}r
catch(IOException e){e.printStackTrace ();} "oYyeT ,?
catch(Exception e){e.printStackTrace ();} lc=C
\S@;>A<J
<"@~
Utility.log(nFileLength); :sBg+MS
& ;+u.X
o~F @1
return nFileLength; @l^=&53T
} Fr)G h>
|.Bb Pfe8f
#"a?3!wr
//保存下载信息（文件指针位置） $@t-Oor;
private void write_nPos() M? oK@i
{ /}Y>_87
try{ >yn%.Uoh@
output = new DataOutputStream(new FileOutputStream(tmpFile)); /GNRu
output.writeInt(nStartPos.length); -tSWYp{
for(int i=0;i<nStartPos.length;i++) pAYH"Q6~)I
{ +n]U3b
// output.writeLong(nPos); *lg1iP{]
output.writeLong(fileSplitterFetch.nStartPos); jBV2]..
output.writeLong(fileSplitterFetch.nEndPos); =/"Of
} lkV% k1w
output.close(); dfe 9)m>
} &eT)c<yhyK
catch(IOException e){e.printStackTrace ();} x{C=rdp__
catch(Exception e){e.printStackTrace ();} 4em7PmT
} sf]y\_zU
/!UuGm
+}X?+Epm
//读取保存的下载信息（文件指针位置） )]!Ps` ,u
private void read_nPos() 2s;/*<WM
{ fEdQR->
try{ VY@uQ#&A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @?{n`K7{`
int nCount = input.readInt(); ,-t3gc1~X
nStartPos = new long[nCount]; 4-=>># P
nEndPos = new long[nCount]; fSl+;|Kn
for(int i=0;i<nStartPos.length;i++) \i "I1xU
{ 7CABM
nStartPos = input.readLong(); Nc[>CgX"@
nEndPos = input.readLong(); cg<10KT
} $# @G!
input.close(); (80]xLEBL
} R,/?p
catch(IOException e){e.printStackTrace ();} )dG7$,g
catch(Exception e){e.printStackTrace ();} \^?BC;s^C
} PX[taDN
Rs{L
B>t$Z5Q^X
private void processErrorCode(int nErrorCode) 9C$b^wHd
{ y)|Q~8r
System.err.println("Error Code : " + nErrorCode); 6t TLyI$+
} HLAWx/c,j"
F^IYx~:
Z~~{!C+G
//停止文件下载 [sTr#9Z
public void siteStop() De4UGX
{ mmAikT#k
bStop = true; LSNa
for(int i=0;i<nStartPos.length;i++) z*YkD"]B
fileSplitterFetch.splitterStop(); kG &.|
^P~%^?(
$=4T# W=m
} d%81}4f:
} ?2%d;tW
//负责部分文件的抓取 bAeC=?U
**FileSplitterFetch.java +e`f|OQ
*/ Iujly f
package NetFox; 2+TCFpv
05LVfgJ'q
_jR%o1Y}
import java.io.*; 5.]+K<:h"A
import java.net.*; rm;'/l8Y-E
Ps+0qqT*
GX&BUP\
public class FileSplitterFetch extends Thread { \s<{V7tq
m(s(2wq"f
~urIA/
String sURL; //File URL wXMKQ)$(
long nStartPos; //File Snippet Start Position BdG~y1%:
long nEndPos; //File Snippet End Position (#BkL:dg
int nThreadID; //Thread's ID ,fpu@@2
boolean bDownOver = false; //Downing is over *$Z}v&-0k
boolean bStop = false; //Stop identical lt|\$Iy(
FileAccessI fileAccessI = null; //File Access interface Sf B+;i'D
^rfY9qMJr8
w0)V3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^&zwO7cS
{ C~ t?<
this.sURL = sURL; ]iRE^o6
this.nStartPos = nStart; wOOBW0tj
this.nEndPos = nEnd; yMq&9R9F
nThreadID = id; (8TB*BhQ_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >N@tInE
} =<e|<EwSZ
`utv@9 _z
jGl8y!aM
public void run() n.ZLR=P4
{ 0^az<!!O#
while(nStartPos < nEndPos && !bStop) uz-,)
{ iZ<^p1i
9 [v=`
Bw;sg;
try{ n1m[7s.[&
URL url = new URL(sURL); dF:@BEo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4sasf94
httpConnection.setRequestProperty("User-Agent","NetFox"); k{;"Aj:iL
String sProperty = "bytes="+nStartPos+"-"; 0?KXQD
httpConnection.setRequestProperty("RANGE",sProperty); N+ZDQa[
Utility.log(sProperty); <cNXe4(
X1&Ug^
3sIW4Cs7)U
InputStream input = httpConnection.getInputStream(); ig<Eyr
//logResponseHead(httpConnection); 1j0OV9-|
4e~^G
l9KLP
byte[] b = new byte[1024]; "RMBV}<T
int nRead; W^npzgDCo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5b45u 6
{ 4YDK`:4I~
nStartPos += fileAccessI.write(b,0,nRead); Ko_Sx.
//if(nThreadID == 1) C~4_Vc*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Yv k Qh{
} BLZ#vJR
PLU8:H@X
=+5z;3
Utility.log("Thread " + nThreadID + " is over!"); JTK>[|c9oE
bDownOver = true; !>fYD8Ft,
//nPos = fileAccessI.write (b,0,nRead); 9qN4f8R
} J!5BH2bg
catch(Exception e){e.printStackTrace ();} x2x)y08
} cKuU#&FaV
} B?Ac
1{+x >Pv:
b?9c\-}
//打印回应的头信息 arJ4^ d
public void logResponseHead(HttpURLConnection con) :W]?6=
{ ^7MhnA
for(int i=1;;i++) Y$xO&\&)
{ Vij P;
String header=con.getHeaderFieldKey(i); [M>Md-pj
if(header!=null) 0q'd }DW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j_N><_Jc
Utility.log(header+" : "+con.getHeaderField(header)); <X[TjP
else h4rIt3`
break; U |I>CDp
} +Go(yS
} [-o`^;
1Vq]4_09g1
qu]ch&"?U
public void splitterStop() I)#=#eI*:
{ 0#(K}9T)
bStop = true; m|q?gX9R
} [Du@go1C
1d/-SxhZ
0dS}pd">k
} VBc[(8o
l`lo5:w
+pYrAqmO-
/* fw>@:m_bK
**FileAccess.java *r!f! eA:
*//文件访问(定位，写) >!+.M9
package NetFox; u\YH,
import java.io.*; 0kN;SSX!
8N<0|u
z;1y7W!v
public class FileAccessI implements Serializable{ |8I #`
@$FE}j_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d,=Kv
RandomAccessFile oSavedFile; >)ZX
long nPos; gfQ&U@N
\)'nxFKqV
=! v.VF\;
public FileAccessI() throws IOException WelB+P2
{ 3/IQ]8g"
this("",0); VM{`CJ2
} `-zdjc d
R"(rL5j
* d6[kY
public FileAccessI(String sName,long nPos) throws IOException Hj ]$
{ /x.TF'Z*
oSavedFile = new RandomAccessFile(sName,"rw"); o?\)!_Z|
this.nPos = nPos; }qfr&Ffh@
oSavedFile.seek(nPos); A.7:.5Cx'
} F\1nc"K/(
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j`^':!
public synchronized int write(byte[] b,int nStart,int nLen) R`=3lY;
{ ToNi<~
int n = -1; >yvP[$]!6
try{ {ZFa +
oSavedFile.write(b,nStart,nLen); >Bp%~8f
n = nLen; -oq!zi4:
} JV'd!5P
catch(IOException e) 5@c,iU-L
{ ,2S <#p!
e.printStackTrace (); BmYU#h
} k*|dX.C:
oR}ir
iHjo3_g)n
return n; Hxr2Q]c?u
} b3b 4'l
~\dpD
TRz~rW k
} 1_:1cF{w
mm$D1=h{|
o^~6RZ
/* c?) pn9
**SiteInfoBean.java 1=#r$H
*/ %Hv$PsSJ
package NetFox; *pP"u::S
DHpU?;|3
a#H=dIj
public class SiteInfoBean { V2es.I
AX**q$'R
`.aL>hf
private String sSiteURL; //Site's URL .Q"3[
private String sFilePath; //Saved File's Path ;t%L(J
private String sFileName; //Saved File's Name ,- ]2s_
private int nSplitter; //Count of Splited Downloading File Te'^O,C)y$
=D5@PHpv(
2`5(XpYe
public SiteInfoBean() 4\pA^%73
{//nSplitter的缺省值为5 dQM# -t4*
//default value of nSplitter is 5 'G(N,vu[@
this("","","",5); $ajw]2kx
} e"r'z n
3FPy"[[
I#eIm3Y?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yE9JMi0
{ i?=3RdP/R1
sSiteURL= sURL; &4*&L.hPM^
sFilePath = sPath; %>I!mD"X\
sFileName = sName; vlIdi@V
this.nSplitter = nSpiltter; qjR;c& qR
p5F[( H|9
>[|:cz
} R5]R pW=G
CyG@
bDUGzezP<
public String getSSiteURL() $L</{bXW
{ YD@V2gK
return sSiteURL; @1n0<V/
} m.K"IXD
{h9#JMIA
q<c).4
public void setSSiteURL(String value) Dj!J 4uD
{ ] {NY;|&I'
sSiteURL = value; :\80*[=;Z
} pbqa
$Z{ fKr
&)s A(
public String getSFilePath() AZl=w`;/O%
{ $ya#-pi`;
return sFilePath; D<xPx
} I*lq0&
uaU!V4-
!]kn=7
public void setSFilePath(String value) 5j]}/Aq
{ N#,4BU
sFilePath = value; Nm,vE7M
} W;KHLHp-
tAc;O[L
$u3N',&
public String getSFileName() ; $y.+5 q
{ 1Eg}qU,:
return sFileName; o.Cj+`0}5
} aaaC8;.
5lU`o
ie$=3nZJ}
public void setSFileName(String value) 8|d[45*q
{ ~(%G;fZ?x
sFileName = value; QT|mN
} K/%aoTO}
,/d-o;W
a#raUF7e
public int getNSplitter() 'm2,7]
{ MnX2sX|
return nSplitter; 5mFi)0={y
} jM7}LV1Ck
x65e,'
$~:hv7%
public void setNSplitter(int nCount) 1%-?e``.
{ hG ]jm
nSplitter = nCount; nEGku]pCH{
} &[Sw:{&*jv
} Ko%rB+d
\/$v@5
{;-$;\D
/* 3[e@mcO
**Utility.java S((8DSt*
*/ ar^`r!ABEh
package NetFox; jWoo{+=D
HFDg@@
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public class Utility { [2FXs52
5o72X k
sV*Q8b*
public Utility() m#SZI}
{ XG[%oL
-[7.VP
,2cw9?<
} bZlAK)
V2y[IeSQ
//线程睡眠 P;y/`_jo
public static void sleep(int nSecond) l%U9g
{ 3n/L;T,X
try{ ?3|ZS8y
Thread.sleep(nSecond); es6e-y@e
} FE5R ^W#u-
catch(Exception e) O^<6`ku
{ y~dW=zO
e.printStackTrace (); Qz<-xe`o8]
} 3dM6zOK
} Wu}Co
:#LB}=HQ
//日志 >:xnjEsi$/
public static void log(String sMsg) ~W#f,mf
{ 7]^Cg;EtM:
System.err.println(sMsg); Oh^X^*I$@
} i3GvTg-X
c]LH.
tb i;X=5
public static void log(int sMsg) P``hw=L
{ a=J?[qrx
System.err.println(sMsg); .dygp"*
} {NFeX'5bP
} ::R^ w"
lt*k(JD
9@j~1G%^
/* l?~ci ;lG
**TestMethod.java p"JSYF 9]
*/ UtutdkaS
package NetFox; V.4j?\#%
MPB6
a_ P[J8j
public class TestMethod { -Z Z$ 1E
?yz%r`;r
(kHR$8GFM
public TestMethod() bXW)n<y
{ ///xx/weblogic60b2_win.exe q5A+%#
try{ e%P;Jj476
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H )}WWXK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zm:=d>D..
SiteFileFetch fileFetch = new SiteFileFetch(bean); !vB%Q$!x
fileFetch.start(); R',w~1RV'
} M;9+L&p=
catch(Exception e){e.printStackTrace ();} 0 mQ3P.9
@b/2'
sHuz10
} +wSm6*j7=
)L!R~F C
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public static void main(String[] args) ]~zJ7I
{ s`J=:>9*
new TestMethod(); :6/OU9f/R
} B#MW`7c
} rrWk&;?
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