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)); zt]8F)l@
} p\I3fI0i
for(int i=0;i<nEndPos.length-1;i++) _`C|K>:
{ ?mV2|;
nEndPos = nStartPos[i+1]; rp @%0/[
} fFC9:9<
nEndPos[nEndPos.length-1] = nFileLength; _@?I)4n|
} LDw.2E
} y+wy<[u
k^JgCC+
Gn6\n'r0
//启动子线程 q~18JB4WPJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7^)yo#i4
for(int i=0;i<nStartPos.length;i++) rY&lx}
{ 6_8yQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U4a8z<l$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kyJKai
nStartPos,nEndPos,i); p? +!*BZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZQR)k:k7
fileSplitterFetch.start(); A$~H`W<yxB
} i+Ne.h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q}'<[Wg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <b4} B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _;x`6LM
nEndPos = " + nFileLength); f[`&3+
// fileSplitterFetch[nPos.length-1].start(); ~6u|@pnI
cWQ &zc
;eFV}DWW
//等待子线程结束 zb~;<:<
//int count = 0; Tz:,l$
//是否结束while循环 .1h\r, #
boolean breakWhile = false; 4y.'O
Z5wDf+
@d5t%V\
while(!bStop) BVv-1$ U^
{ o|n+;h
write_nPos(); 7 mA3&<&q
Utility.sleep(500); ~s?y[yy6i
breakWhile = true; DjZTr}%q
blG?("0!
I8W9Kzf
for(int i=0;i<nStartPos.length;i++) :[PA.Upi
{ hOqNZ66{
if(!fileSplitterFetch.bDownOver) v!S(T];)
{ lS2`#l>
breakWhile = false; `LwZ(M-hI
break; %0u5d$bq
} bLggh]Fh
} Mu" vj*F
if(breakWhile) <X5V]f
break; _s=<Y^l%x
/K,@{__JP
|e+r~).4B
//count++; T/%k1Hsa4H
//if(count>4) kDiR2K&
// siteStop(); sBxCi~
} )DW".c
*xeJ4h
]G! APE
System.err.println("文件下载结束！"); kmJ<AnK
} tsB}'+!v#
catch(Exception e){e.printStackTrace ();} g]b%<DJ
} 21?>rezJ
pXNH
aO:A pOAO
//获得文件长度 xy)W_~Mk
public long getFileSize() +miL naO~L
{ '7]9q#{su
int nFileLength = -1; 5"x1Pln
try{ >G0ihhVt
URL url = new URL(siteInfoBean.getSSiteURL()); ]VN1Y)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =*?XZA)c
httpConnection.setRequestProperty("User-Agent","NetFox"); nwDW<J{f|U
c)QOgXv
Z 2uU'T
int responseCode=httpConnection.getResponseCode(); "LZv\c~v,%
if(responseCode>=400) 3\B~`=*q/
{ `1 Tg8
processErrorCode(responseCode); }V+&o\4
return -2; //-2 represent access is error _=qk.|p/
} m}m|(;T
{X\FS
|z)7XK
String sHeader; O4W2X@
XQ Si
X=k|SayE8
for(int i=1;;i++) X*r?@uK5
{ /5XdZu6k`h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0NSCeq%;6q
//Utility.log(in.readLine()); %)r1?H} #%
sHeader=httpConnection.getHeaderFieldKey(i); i?F~]8
if(sHeader!=null) mndNkK5o
{ H//,qxDc
if(sHeader.equals("Content-Length")) 4d-"kx3X
{ 6A} 45
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y|#Fu
break; `]2y=f<{X
} x1`Jlzrp,
} j+3=&PkA.]
else )5U7w
break; ; JHf0
} e5sQl1
} CakB`q(8
catch(IOException e){e.printStackTrace ();} {<Vw55)#0Q
catch(Exception e){e.printStackTrace ();} h`:gMhn
}4*~*NoQ
,xC@@>f
Utility.log(nFileLength); =NL(L
3{- 8n/4 k
9\R+g5
return nFileLength; v$|cF'yyF=
} bO gVCg
2MKB(;k
9C1\?)"D^e
//保存下载信息（文件指针位置） ]*AQT7PH
private void write_nPos() !2g*=oY
{ yKOC1( ~
try{ NFb<fD[C
output = new DataOutputStream(new FileOutputStream(tmpFile)); %t,Fxj4F
output.writeInt(nStartPos.length); AhSN'gWpbF
for(int i=0;i<nStartPos.length;i++) &;%LTF@I,
{ E"Y[k8-:2/
// output.writeLong(nPos); Ivc/g,
output.writeLong(fileSplitterFetch.nStartPos); sMWNzt
output.writeLong(fileSplitterFetch.nEndPos); y)+lU
} h!]=)7x;
output.close(); i}LVBx"K(
} $%3%&+z$I
catch(IOException e){e.printStackTrace ();} ,y*|f0&"~
catch(Exception e){e.printStackTrace ();} $[*<e~?
} DqBiBH[%h
mp>Ne6\Tu
,A!0:+
//读取保存的下载信息（文件指针位置） 8}!WJ2[R
private void read_nPos() 'di(5
{ Eg#WR&Uq"
try{ ksli-Px
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^/$bd4,z
int nCount = input.readInt(); kt hy9<!$
nStartPos = new long[nCount]; m2PI^?|e
nEndPos = new long[nCount]; `9p;LZC1K
for(int i=0;i<nStartPos.length;i++) a.s5>:Ct
{ g,5Tr_
nStartPos = input.readLong(); zM|Y X<
nEndPos = input.readLong(); sb*)K,U
} =E-V-?N\
input.close(); ]9NA3U7F
} 6n$g73u<=3
catch(IOException e){e.printStackTrace ();} ~~3 BV,
catch(Exception e){e.printStackTrace ();} xEqr3(
} :PDyc(s{
E(Y}*.\]#s
XlU`jv+
private void processErrorCode(int nErrorCode) 77p8|63
{ pu6@X7W"
System.err.println("Error Code : " + nErrorCode); pK@8=+
} i}r|Zo
ORo,.#<
(<xl _L:*.
//停止文件下载 xr1,D5
public void siteStop() TKZ[H$Z
{ W(,3j{d2i
bStop = true; _T.k/a
for(int i=0;i<nStartPos.length;i++) 5}"9)LT@@w
fileSplitterFetch.splitterStop(); EHX/XM
@PyZ u7'
|#`qP^E
} me&'BQ
} {Z(kzJwN
//负责部分文件的抓取 :c`Gh< u
**FileSplitterFetch.java vAjvW&'g
*/ (E]q>'X
package NetFox; ~~X-$rtU
i5jsM\1j
[^2c9K^NK
import java.io.*; 0hM!#BU5K
import java.net.*; R>n=_C
($r-&]y
Ipyr+7/zJ
public class FileSplitterFetch extends Thread { Ud'/ 9:P
`ehcj G1nY
i9j#Tu93 f
String sURL; //File URL .h[yw$z6
long nStartPos; //File Snippet Start Position LF\HmKM,
long nEndPos; //File Snippet End Position bOS; 1~~
int nThreadID; //Thread's ID X6SWcJtSw
boolean bDownOver = false; //Downing is over J>p6')Y6~
boolean bStop = false; //Stop identical ;dZuO[4\
FileAccessI fileAccessI = null; //File Access interface B 42t
B0|!s
'nSo0cyQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rki0!P`
{ }*s`R;B|,
this.sURL = sURL; w0`8el;
this.nStartPos = nStart; #l#8-m8g)
this.nEndPos = nEnd; K:(E"d;
nThreadID = id; $bsD'Io
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S>V+IKW;(
} I> BGp4AQ
T?HW=v_a
}YCpd)@
public void run() 0<#>LWaM_
{ GYwU3`{
while(nStartPos < nEndPos && !bStop) jcL%_of
{ +Fa!<txn
^c|_%/
&r)[6a$fW
try{ Yh2[ nF_
URL url = new URL(sURL); G[$g-NU+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v,^W& W.
httpConnection.setRequestProperty("User-Agent","NetFox"); Z|$M 9E
String sProperty = "bytes="+nStartPos+"-"; x ?24oO
httpConnection.setRequestProperty("RANGE",sProperty); 1U6z2i+y
Utility.log(sProperty); _kXq0~
K$/&C:,Q
&$g{i:)Z
InputStream input = httpConnection.getInputStream(); ;7E c'nC4
//logResponseHead(httpConnection); 2xK v;
V;29ieE!
3>QkO.b
byte[] b = new byte[1024]; w?:tce
int nRead; @A'@%Zv-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'M!M$<j
{ Lz{z~xNHW.
nStartPos += fileAccessI.write(b,0,nRead); aI;-NnC
//if(nThreadID == 1) h5<eU;Rw+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G4](!f!Kv
} K*S3{s%UR
#g=
z}w7X6&e
Utility.log("Thread " + nThreadID + " is over!"); #pcgfVl
bDownOver = true; W`v$-o-
//nPos = fileAccessI.write (b,0,nRead); @8*lqV2
} #+#^cqjZ
catch(Exception e){e.printStackTrace ();} AF\Jh+ynT!
} 0TWd.+
} g5:?O,?
'S%H"W\
{hFH6]TA
//打印回应的头信息 $Da?)Hz'F
public void logResponseHead(HttpURLConnection con) y#zO1Nig`
{ Z5|BwM
for(int i=1;;i++) i936+[
{ V:h7}T95
String header=con.getHeaderFieldKey(i); O',Vce$
if(header!=null) LyH1tF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !|Wf mU
Utility.log(header+" : "+con.getHeaderField(header)); ;2P
else }`.d4mm
break; &EmG\vfE
} {B-*w%}HU
} IGNU_w4j
)$ M2+_c
LhRd0
public void splitterStop() Swr4De_5
{ Z C<+BKS
bStop = true; G>Hg0u0!,
} $b(CN+#
rCUGaf~
nF B]#LLv
} MXiQWg$
dTjDVq&Hz
9y&bKB2,
/* J6Vx7
**FileAccess.java s'|t2`K("
*//文件访问(定位，写) F?^L^N^
package NetFox; :gO5#HIm
import java.io.*; />6ECT
&~=r .T
.cm2L,1h
public class FileAccessI implements Serializable{ "VDMO^
Al=ByX@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B"8jEYT5
RandomAccessFile oSavedFile; -9::M}^2
long nPos; k%BU&%?1
.,20_<j%=
#q4uS~
public FileAccessI() throws IOException df!i}L
{ ^t:dcY7
this("",0); TJ1h[
} PV:J>!]
>n^780S|
U*b7 Pxq;
public FileAccessI(String sName,long nPos) throws IOException Z?xRSi2~7
{ IVY)pS"pR"
oSavedFile = new RandomAccessFile(sName,"rw"); @{W"mc+
this.nPos = nPos; R0%M9;>1
oSavedFile.seek(nPos); AmC?qoEWQ7
} zy5FO<->
sn"z'=ch
xv&h>GOg
public synchronized int write(byte[] b,int nStart,int nLen) oC-v>&bW
{ yzv"sd[8N
int n = -1; f,4erTBH
try{ . P+Qu
oSavedFile.write(b,nStart,nLen); MqJ5|C.q
n = nLen; t1]/Bw`j/
} Vd(n2JMtG
catch(IOException e) Nte$cTjX
{ 9z..LD(
e.printStackTrace (); ES?*w@x
} ?w+ V:D
_OC@J*4.
BlQX$s]
return n; ^Kg n:l
} fjOq@thD
T;?k]4.X
aydNSgu
} ^H&U_
> K?OsvX
[}]yJ+)
/* rlD!%gG2x
**SiteInfoBean.java *= ?|n
*/ 15hqoo9!
package NetFox; Fj(GyPFG
/0 4US5En
P:t .Nr"
public class SiteInfoBean { FF~r&h8H
%4f.<gz~r|
~`C_B]3|
private String sSiteURL; //Site's URL O`Gq7=X
private String sFilePath; //Saved File's Path vaGF(hfTA
private String sFileName; //Saved File's Name N@L{9ak1
private int nSplitter; //Count of Splited Downloading File e"52'zAV-
~7U~
r4fHD~#l{
public SiteInfoBean() ^:]$m;v]
{//nSplitter的缺省值为5 6tndC o;`
//default value of nSplitter is 5 ,|B-Nq
this("","","",5); H#DvCw
} 8'HS$J;C
wV"`Du7E;
"J`&"_CyZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +l/v`=C
{ {BT/P!
sSiteURL= sURL; S.)Jp-&K
sFilePath = sPath; }&t>j[
sFileName = sName; avL_>7q
this.nSplitter = nSpiltter; r]UF<*$
V@!)Pw
4uo`XJuQ
} dniU{v
:#pdyJQ_
6oNcj_?7?q
public String getSSiteURL() ~e 1l7H;
{ b.@a,:"
return sSiteURL; =i&,I{3
} 'Vo8|?.WhX
%^pi
XS[L-NHG
public void setSSiteURL(String value) Ch_rV+
{ 8s@N NjV
sSiteURL = value; b1.*cIv}
} sfj+-se(K.
DzQBWY] )
/N"3kK,N
public String getSFilePath() UnF8#~
{ RhH1nf2UR
return sFilePath; g4$(%]
} n%s%i-[5B
\A"o[A2v
by X!,
public void setSFilePath(String value) B6Vlc{c5SO
{ e~9O#rQI
sFilePath = value; BVNW1<_:
} V@G#U[D
X,7y|tb
6!ve6ZB[p
public String getSFileName() KLg1(W(
{ 3}0\W.jH
return sFileName; 6'r8.~O
} Sw\*$g]
$'498%K2
t'vt'[~,U
public void setSFileName(String value) 0jf6 z-4
{ \ ;npdFy
sFileName = value; ,vJt!}}
} :TH cI;PG8
tcuwGs>_
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public int getNSplitter() QO/0VB42
{ f'^uuO#x
return nSplitter; d,b4q&^X8
} 5^u$zfR
`hi=y BO
<+i(CGw
public void setNSplitter(int nCount) $zMshLT
{ mll:rWC)
nSplitter = nCount; _h~ksNm5u
} amu;grH
} qN)y-N.LI(
~#A}=,4>
&9p!J(C
/* Z<-_Y]4j
**Utility.java %9J@##+
*/ {ALEK
package NetFox; nqcq3o*B
J:L+q}A
MzJCiX^
public class Utility { AK2Gm-hHK
6pt_cpbR
L*(9Hti
public Utility() hmO2s/~
{ _M&TT]a
= xO03|T;6
n/+X3JJ
} /BL:"t@-
nT6y6F_e
//线程睡眠 ,,'jyqD
public static void sleep(int nSecond) H}^'
{ +I3jI <
try{ :v&[!
Thread.sleep(nSecond); SS=<\q#MS
} >cu%Cs=m
catch(Exception e) ,ks2&e
{ +$dJA
e.printStackTrace (); Z*%;;&?
} k~Ex_2;#
} m[9.'@ye
v= 55{
//日志 {3~VLdy
public static void log(String sMsg) ^\\3bW9}H
{ _R4}\3}!
System.err.println(sMsg); A6N6e\*
} 7L{1S v
~MC|
Xz+%Ym
public static void log(int sMsg) -Zt!H%U
{ u6qK4*eAD
System.err.println(sMsg); e7vm3<m4
} CdolZW-!"
} 2"Os9 KD
TR"C<&y$j
1K72}Gj)ZL
/* \iuR+I
**TestMethod.java $^Fl*:6
*/ l& :EKh
package NetFox; 'solCAy
Q#bW"},^k
9mF'
public class TestMethod { K`4rUEf}V"
(!~cOx
h [TwaR
public TestMethod() h3ygL"k
{ ///xx/weblogic60b2_win.exe jh5QIZf=
try{ NVyBEAoh
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w_9^YO!!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8Sbz)X
SiteFileFetch fileFetch = new SiteFileFetch(bean); [);oj<
fileFetch.start(); ZoW1Cc&p
} z+"tAVB[i
catch(Exception e){e.printStackTrace ();} uZqL'l+/y
B=_w9iVN
o`U}uqrO
} ,+=9Rp`md
}V?m =y [
%b6$N_M{H1
public static void main(String[] args) _:x]'w%
{ 9^gYy&+>6]
new TestMethod(); E C?}iP
} Ss3p6%V/
} ^QK`z@B
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