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)); F*-+5nJ&@
} b6NGhkr'\
for(int i=0;i<nEndPos.length-1;i++) Y[0mTL4IO
{ ,4HZ-|EOZ
nEndPos = nStartPos[i+1]; puAjAvIax
} Oq*;GR(Q
nEndPos[nEndPos.length-1] = nFileLength; Oy_%U*
} \7PC2IsT3
} -&EU#Wqh
A5E^1j}h@
F4]=(T
//启动子线程 `-w,6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WX* uhR
for(int i=0;i<nStartPos.length;i++) 8o i{%C&-
{ u<JkP <"S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x~QZVL=:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2. q\!V}yQ
nStartPos,nEndPos,i); l4gZHMh'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #.{ddY{
fileSplitterFetch.start(); kgHZaQnD
} ?kULR0uL+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W3gHzT?{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "&C>=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O>"T*
nEndPos = " + nFileLength); ~"VM_Lz]5
// fileSplitterFetch[nPos.length-1].start(); ue1g(;
F~sUfqiJ'
f^)iv ]p
//等待子线程结束 JAX`iQd
//int count = 0; \h/)un5
//是否结束while循环 ;}H*|"z;!
boolean breakWhile = false; VVbFn9+V
E[Q2ZqhgbP
wGw<z[:f
while(!bStop) op($+Q
{ VCzb[.
write_nPos(); G 2`hEX%
Utility.sleep(500); ++ZP X'|
breakWhile = true; a@^)?cH!z
biG :Xn
w7c0jIf{
for(int i=0;i<nStartPos.length;i++) XS$#\UQ
{ :_|Xr'n`A
if(!fileSplitterFetch.bDownOver) ojyP.R
{ D63?f\
breakWhile = false; Z*n4$?%W
break; qpjiQ,\:b
} \]0#jI/:
} C;?<WtH
if(breakWhile) \dbaY:(
break; GX=U6n>
J"-/ok(<@
7 lSR
//count++; {:#c1d2@8
//if(count>4) "E@A~<RKP
// siteStop(); DzIV5FG
} 6rM{r>
5me#/NqLHY
'Ck:=V%}g
System.err.println("文件下载结束！"); LLL;SNY
} Zrzv';
catch(Exception e){e.printStackTrace ();} Yx&d\/9
} a ?\:,5=
H43d[@h
Z<*"sFpAO
//获得文件长度 hW9U%-D
public long getFileSize() ,/qY 9eh
{ T 0qM"
int nFileLength = -1; caxOxRo\
try{ d@tf+_Ih
URL url = new URL(siteInfoBean.getSSiteURL()); A"1%E.1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }~p%e2<
httpConnection.setRequestProperty("User-Agent","NetFox"); _gEojuaN
_U9.u#>sV
Jpc%i8
int responseCode=httpConnection.getResponseCode(); /A+5q\8G
if(responseCode>=400) /Ny#+$cfk
{ hj\A-Yf
processErrorCode(responseCode); bYmk5fpRG
return -2; //-2 represent access is error &fsk ESV0
} wD/jN:
Dw>)\\n{Kl
QQ=Kj%R
String sHeader; <\$?.tTZ{
&Xc=PQ:I
)%<,JD
for(int i=1;;i++) gD;T"^S+
{ bM2x (E\O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 96S$Y~G#&
//Utility.log(in.readLine()); !K+hXQE1
sHeader=httpConnection.getHeaderFieldKey(i); 1h#/8X
if(sHeader!=null) NZO86y/
{ ac6@E4 _
if(sHeader.equals("Content-Length")) :9e4(7~ona
{ ("YWJJ'H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @NL37C
break; 1!yd(p=cL
} xLms|jS
} Xpv<v[a
else -zWNQp$
break; D2J)qCK1)
} C^c<s
} bc NyB$S
catch(IOException e){e.printStackTrace ();} \qTp#sF
catch(Exception e){e.printStackTrace ();} ^y%8_r&
JDW/Mc1bh
1Y%lt5,*
Utility.log(nFileLength); -0TI7 @
HXX9D&c4R
a^\F9^j
return nFileLength; g}IOHE
} zl|+YjR
Qn~{TZz
\y6Y}Cv
//保存下载信息（文件指针位置） ko|M2\
private void write_nPos() _v(5vx_ {
{ #s' `bF^
try{ 2bG92
output = new DataOutputStream(new FileOutputStream(tmpFile)); FS!9 j8
output.writeInt(nStartPos.length); _z1Qr?cY
for(int i=0;i<nStartPos.length;i++) 7IQaXcl
{ 'T(Q
// output.writeLong(nPos); |onLJY7)
output.writeLong(fileSplitterFetch.nStartPos); s Ytn'&$\
output.writeLong(fileSplitterFetch.nEndPos); 4>2\{0r
} O9m sPb:
output.close(); zo("v*d*q
} I[b{*g2Zw
catch(IOException e){e.printStackTrace ();} F/,6Jh
catch(Exception e){e.printStackTrace ();} "kC6G%
} &ld<fa(w+2
:5'hd^Q
n*i&o;5
//读取保存的下载信息（文件指针位置） TtnJ u*
private void read_nPos() 97<Z,q72Y
{ epG]$T![
try{ 1]Cbi7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xFJT&=Af W
int nCount = input.readInt(); wWSw0 H/
nStartPos = new long[nCount]; a8v\H8@X
nEndPos = new long[nCount]; >rSCf=
for(int i=0;i<nStartPos.length;i++) C1(RgY|
{ & P%#
nStartPos = input.readLong(); ,izp^,`
nEndPos = input.readLong(); Zop/ MeI
} 4^k8|#c
input.close(); Dx=RLiU9
} 1r*yYm'
catch(IOException e){e.printStackTrace ();} s&+`>
catch(Exception e){e.printStackTrace ();} q(WGvl^r
} Lsai8 B
.gNziDO
UtC<TBr
private void processErrorCode(int nErrorCode) \So)g)K
{ P[$idRS&
System.err.println("Error Code : " + nErrorCode); P.g./8N`z
} Nq^o8q_
OoRg:"9{#
he@Y1CY
//停止文件下载 <%W&xk
public void siteStop() S,udpQ7
{ U>00B|<GJ
bStop = true; kGC*\?<LmR
for(int i=0;i<nStartPos.length;i++) ^CM@VmPp
fileSplitterFetch.splitterStop(); `:R9M+ OX
,_/\pX0
O2yD{i#l*#
} wDSwcNS
} v-^<,|vm2f
//负责部分文件的抓取 GMkni'pV
**FileSplitterFetch.java 8|$g"?CU
*/ 9~2iA,xs
package NetFox; @HnahD
osmCwM4O
'66nqJb*
import java.io.*; QFN9j
import java.net.*; M?;YpaSe+
90,UhNz9D
;49sou
public class FileSplitterFetch extends Thread { m6H+4@Z-;(
@MoCEtt
:cIPX%S
String sURL; //File URL |}:q@]dC#
long nStartPos; //File Snippet Start Position !6sR|c"~j
long nEndPos; //File Snippet End Position O'xp"e,
int nThreadID; //Thread's ID Os]. IL$
boolean bDownOver = false; //Downing is over :oYSvK7>
boolean bStop = false; //Stop identical 3q@H8%jcw
FileAccessI fileAccessI = null; //File Access interface 69Z`mR
7l09
^^24a_+2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d_f*'M2Gv
{ (&V)D?/hS
this.sURL = sURL; .QA1'_9
this.nStartPos = nStart; wlh%{l
this.nEndPos = nEnd; L_+Fin
nThreadID = id; O*N:.|dUw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ar'VoL}
} m(1ot M9
foY]RkW9
<VQ@I
public void run() &oJ[ *pQ
{ NXz/1ut%
while(nStartPos < nEndPos && !bStop) >HzTaXCR[
{ kp!(e0n
EFu$>Z4
kQ_Vj7
try{ 9x(t"VPuS
URL url = new URL(sURL); &|Rww\oJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7fd,I%v
httpConnection.setRequestProperty("User-Agent","NetFox"); 9"L!A,&'
String sProperty = "bytes="+nStartPos+"-"; { i4`-w
httpConnection.setRequestProperty("RANGE",sProperty); ,6f6r
Utility.log(sProperty); Se\iMs
Q&@<?K9
>}C:EnECy
InputStream input = httpConnection.getInputStream(); 0C"2?etMx
//logResponseHead(httpConnection); P!)F1U]!
a^X% (@Sg
Nv=%R
byte[] b = new byte[1024]; y1Wb/ d
int nRead; \q^dhY>)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4(Y-TFaf
{ uKJo5%>
nStartPos += fileAccessI.write(b,0,nRead); EpCNp FQT<
//if(nThreadID == 1) $bBUL C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CG J_k?h
} sebuuL.l0<
jxq89x
P8w56
Utility.log("Thread " + nThreadID + " is over!"); }XRfHQk
bDownOver = true; ^L\w"`,~
//nPos = fileAccessI.write (b,0,nRead); up~p_{x)Q
} 5g'aNkF6>
catch(Exception e){e.printStackTrace ();} (tT%rj!
} w*(1qUF#%
} ,wHlU-%
=BV_?
0&Iu+hv
//打印回应的头信息 ~X'hRNFx~
public void logResponseHead(HttpURLConnection con) })q8{Qj!
{ NID2$p
for(int i=1;;i++) O-~cj7 0\
{ MRK3Cey}%
String header=con.getHeaderFieldKey(i); OKj\>3
if(header!=null) *Ct ^jU7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P`_Q-vu
Utility.log(header+" : "+con.getHeaderField(header)); a+9_sUq
else \!0~$?_)P
break; 3cNr~`7
} Y]B9*^d<
} q'Y)Y(d
u=#_8e(9Z
Cs,t:ajP
public void splitterStop() ,ob)6P^rw
{ Q%V530 P;
bStop = true; u2U+uD@yA
} wNh\pWA
]*{tno
'X_%m~}N
} \@^` G
^~bAixH^k
H4M`^r@)'
/* 4]%MrSjS
**FileAccess.java `{}DLaD9
*//文件访问(定位，写) "M %WV>
package NetFox; !;Ctz'wz
import java.io.*; E-?JHJloU
>bO}sx1?
VrT0S
public class FileAccessI implements Serializable{ 'm/`= QX
RNcnE1=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f4|ir3oy
RandomAccessFile oSavedFile; }|c-i.0=
long nPos; 7|)K!
C}:_&^DQ
yoBR'$-=
public FileAccessI() throws IOException Uo|T6N
{ NnY+=#j7L
this("",0); _o>?\:A
} T{F 'Y%
sB'~=1m^
d! _8+~
public FileAccessI(String sName,long nPos) throws IOException Cg^1(dBd[9
{ dQNW1-s
oSavedFile = new RandomAccessFile(sName,"rw"); 1%N[DA^<\
this.nPos = nPos; Y1{*AV6ev6
oSavedFile.seek(nPos); eTY(~J#'
} ]; B`'Ia
M-C>I;a
#ePtfRzJ
public synchronized int write(byte[] b,int nStart,int nLen) A_5M\iN\
{ ]Lm?3$u$
int n = -1; ( D@U%
try{ Qf}}/k|)k
oSavedFile.write(b,nStart,nLen); TM,Fab &
n = nLen; g6.Tx]?b$
} (.g?|c
catch(IOException e) OX{2@+f#
{ FyllVrK
e.printStackTrace (); }eLth0d`'o
} 73+)> "x>
r}#,@<
qu/b:P
return n; 8fb<hq<
} a0&R! E;
b5^-qc6X
;k,#o!>
} IvB)d}p
5VE9DTE
A_|X54}w&
/* Twk,R. O
**SiteInfoBean.java \U HI%1^
*/ xG,L*3c{o
package NetFox; tI+P&L"
I@I-QiI
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public class SiteInfoBean { U#(#U0s*-
%I%OHs
\7*"M y*
private String sSiteURL; //Site's URL qW9~S0sl
private String sFilePath; //Saved File's Path *<ww~^a
private String sFileName; //Saved File's Name ?&@a{-
private int nSplitter; //Count of Splited Downloading File '2S?4Z
>s>{+6e
Uc]sWcR
public SiteInfoBean() `& ]H`KNa
{//nSplitter的缺省值为5 OUtMel_
//default value of nSplitter is 5 &MP +
this("","","",5); w(!COu
} Uk0 0lPG.U
sN@=Ri?\
kaNK@a=e|/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R9^RG-x
{ s.>;(RiJd
sSiteURL= sURL; `SG8w_
sFilePath = sPath; ::p(ViYG
sFileName = sName; )'axJ
this.nSplitter = nSpiltter; L9,O,f
k6^!G"
eq7>-Dmi@
} jmn<gJ2Of
#;s5=aH
q#P@,|nc:
public String getSSiteURL() H.!\j&4j
{ Bx ru7E"
return sSiteURL; Cg];UB}k
} nT/Azg
xtX`3=s
yMKVF`D*
public void setSSiteURL(String value) t@3y9U$
{ OEXa^M4x
sSiteURL = value; fH?s~X]
} [?moS!
Kb*X2#;*
A%%Vyz
public String getSFilePath() ac#I$V-
{ VK^m]??s_
return sFilePath; ?m:,hI
} 75*q^ui
# 4;(^`?
9=p/'d8
public void setSFilePath(String value) .%x%(olf
{ V-w{~
sFilePath = value; Y]:Ch (Q
} |&AZ95v
9"b =W@
9{XV=a v
public String getSFileName() pij%u<
{ O <"\G!y~
return sFileName; N:&EFfg3
} >\ x!a:}
+L|-W9"@3
%p8#pt\$7
public void setSFileName(String value) w)xfP^M#
{ oS#PBql4
sFileName = value; noQS bI @
} 4ZrRgx2MD
P,={ C6*
V D.T=(
public int getNSplitter() fW3NH7aUG
{ >A ?,[p`<
return nSplitter; )^LiALh
} I9O%/^5^[w
T1g3`7C3
lkaWwjv_D
public void setNSplitter(int nCount) cX4I+Mf
{ )6:1`&6
nSplitter = nCount; wlw`%z-B2
} yp"h$
} _j}jh[M
7'idjcR
%>!$eCX
/* 1Y(NxC0P=g
**Utility.java 4)NbQ[
*/ Vl%UT@D|
package NetFox; \,-e>
DW0N}>Gp*
\<W/Z.}/
public class Utility { 5LJ0V
]jgMN7
BY`vs+]XY
public Utility() MWJ}
{ Tga%-xr+
n'qWS/0U=
);=0cnr3
} .njk^,N
-SUK[<=X
//线程睡眠 a9g~(#?a
public static void sleep(int nSecond) ;2[o>73F
{ 0t2n7Y?N
try{ =;~*YD(%/
Thread.sleep(nSecond); sny$[!)
} U%rq(`;
catch(Exception e) H_FT%`iM
{ ob]j1gYb
e.printStackTrace (); UM:]QbaIn
} j]J-#J
} ,C0D|q4/!.
tui5?\
//日志 Hd57Iw
public static void log(String sMsg) L'u*WHj|v
{ <HH\VG\H6
System.err.println(sMsg); #T++5G
} K8RV=3MBLD
l-$5CO
U<I]_]
public static void log(int sMsg) _f"KB=A_x
{ rVZlv3
System.err.println(sMsg); tP4z#0r2
} 9xaieR
} sQBKzvFO3
Q PrP3DK
I+W:}}"j
/* k|`Qk!tr
**TestMethod.java eL88lV]I
*/ cy0j>-z
package NetFox; !3`X Gg
jx14/E+^
qi$nG_<<Z
public class TestMethod { %>Mcme>(W
%\T#Ik~3
m\G45%m
public TestMethod() *R3^:Y&
{ ///xx/weblogic60b2_win.exe <b-OdOg
try{ [xo-ZDIoG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _o? I=UN2:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `t3w|%La}
SiteFileFetch fileFetch = new SiteFileFetch(bean); LjCUkbzQF
fileFetch.start(); rqz48~\lJ
} Nr?CZFN#
catch(Exception e){e.printStackTrace ();} +<bvh<]Od
^Q9K]Vo
KzQuLD(e
} = OzpI
QYc/f"9
z&yVU<;
public static void main(String[] args) Mh]4K"cs
{ j937tn!Q
new TestMethod(); BAojP1}+,
} ;:/C.%d
} zMh`Uqid
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