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)); g/2eY$6Z
} :Jz@`s1n
for(int i=0;i<nEndPos.length-1;i++) AzwG_XgM)
{ Sjogv
nEndPos = nStartPos[i+1]; pP`KI'aUN
} %I&[:
nEndPos[nEndPos.length-1] = nFileLength; ;g M$%!&
} BRu/pyxG
} mF|7:zSo
[`u3SN/P
ELlTR/NW
//启动子线程 GG KD8'j]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /J-:?./
for(int i=0;i<nStartPos.length;i++) g'F{;Ur
{ _Coh11
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T<\!7RnLc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <o\2-fWvY
nStartPos,nEndPos,i); aeP 6JHj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Xw|t.0
fileSplitterFetch.start(); ~gjREl,+D#
} m3La;%aA0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T==(Pw7R7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rTR4j>Ua~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ai 9UB=[R
nEndPos = " + nFileLength); 6jGPmOM/
// fileSplitterFetch[nPos.length-1].start(); %kcyE<c
D)u 9Y
>*5+{~k~4
//等待子线程结束 RH+'"f
//int count = 0; r-ldqj
//是否结束while循环 /%fa_+,|-
boolean breakWhile = false; 0%9Nf!j
mM&*_#( 6
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while(!bStop) x9c/;Q&m
{ UX9r_U5)
write_nPos(); $h({x~Oj9
Utility.sleep(500); JpFfO<uO
breakWhile = true; :-I~-Yj
3e<FlH{
FzDZ<dJ
for(int i=0;i<nStartPos.length;i++) |#r[{2sS
{ 8, >YB+Hb
if(!fileSplitterFetch.bDownOver) TvEN0RV2
{ (Nky?*
breakWhile = false; +&w=*IAKZ
break; q $Hg\ {c
} e2SU)Tr%b
} |+^-b}0
if(breakWhile) I^5T9}>Q
break; ]G0`W6;$]
YEEgDw]BQ
QTN _Z#'
//count++; g' xR$6t
//if(count>4) V ifQ@
// siteStop(); /<HEcB
} Y[A`r0
=s2dD3Fr|
t5%\`Yo?
System.err.println("文件下载结束！"); HlkG^:)
} :uAW
catch(Exception e){e.printStackTrace ();} s[V$fvW
} <By6%<JTn
p8>.Q/4
?ah<Qf]
//获得文件长度 =ZsM[wd
public long getFileSize() MZ(TST"
{ q+MV@8w
int nFileLength = -1; M>mk=-l
try{ v}=3
URL url = new URL(siteInfoBean.getSSiteURL()); b9ON[qOMN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {\OIowa
httpConnection.setRequestProperty("User-Agent","NetFox"); @$5GxIw<l
e$k]z HlQ
>bf29tr
int responseCode=httpConnection.getResponseCode(); 0L34)W
if(responseCode>=400) -XVC,.Ly
{ hSgfp
processErrorCode(responseCode); ZWC-<QO"<
return -2; //-2 represent access is error 6,"fH{Bd
} }),tk?\
AxaabS$\
Pez 7HKW:
String sHeader; TK)Kq
iY=M67V
lWv3c!E`
for(int i=1;;i++) _]"5]c&*3
{ 'L*nC T;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OIF0X!
//Utility.log(in.readLine()); &&0,;r,-)
sHeader=httpConnection.getHeaderFieldKey(i); |(gq:O
if(sHeader!=null) Lx-ofN\
{ Lp; {&=PIo
if(sHeader.equals("Content-Length")) c2}?[\U]
{ E^.y$d~dS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f`5e0;zm
break; uzO%+B!
} f\Bd lOJ>
} }+[H~8)5
else y.AF90Q>)
break; UFxQ-GV4
} m6aq_u{W
} +\FTR
catch(IOException e){e.printStackTrace ();} 5!ll #/ {`
catch(Exception e){e.printStackTrace ();} /B$"fxFf
D6iHkDTg
ti:qOSIDTA
Utility.log(nFileLength); 7$(>Z^ Em
a!,q\p8<t0
~q]+\qty4
return nFileLength; mPNT*pAO
} f>)k<-<yj
r\y~ :
%]JSDb=C
//保存下载信息（文件指针位置） u>Z0ug6x
private void write_nPos() Epm\=s
{ $oO9N^6yF
try{ eRC /Pr
output = new DataOutputStream(new FileOutputStream(tmpFile)); .:tAZZ
output.writeInt(nStartPos.length); )5Ddvz>+
for(int i=0;i<nStartPos.length;i++) A KO#$OJE
{ n*6b*fl
// output.writeLong(nPos); \UI7H1XDH
output.writeLong(fileSplitterFetch.nStartPos); ]X,C9
output.writeLong(fileSplitterFetch.nEndPos); [&n2 yt
} m~%\f8w-x
output.close(); @O}%sjC1
} ;z;O}<8s
catch(IOException e){e.printStackTrace ();} i,R<`K0
catch(Exception e){e.printStackTrace ();} Kk2PWJ7
} X>w(^L*>
L]L-000D(
-LL49P6
//读取保存的下载信息（文件指针位置） \|Pp%U [
private void read_nPos() (W3~r
{ jX^uNmb
try{ 8kQ >M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Vx@JP93|
int nCount = input.readInt(); SI=vA\e
nStartPos = new long[nCount]; Z~^)B8
nEndPos = new long[nCount]; .g.v
for(int i=0;i<nStartPos.length;i++) 'rJkxU{
{ A4.Q\0
nStartPos = input.readLong(); WJ$D]7
nEndPos = input.readLong(); * B!uYP
} YC#N],#
input.close(); j )6A
} +E7s[9/r
catch(IOException e){e.printStackTrace ();} -QL_a8NL
catch(Exception e){e.printStackTrace ();} dzMlfJp
} 4l+"J:,
`_C4L=q"
OD!b*Iy|
private void processErrorCode(int nErrorCode) EnXNTat})
{ !T/^zc;G
System.err.println("Error Code : " + nErrorCode); {-IH?!&v
} 5BCHWX*y
Hc1S:RW
:T(3!}4
//停止文件下载 )J4XM(
public void siteStop() hjywYd]8
{ DjK:)
bStop = true; '#REbY5ev
for(int i=0;i<nStartPos.length;i++) oJJ2y
fileSplitterFetch.splitterStop(); 0R&$P6
b f.__3{
5LU8QHj3
} ; F% 3b47
} ~aKxwH
//负责部分文件的抓取 bD[W`yW0
**FileSplitterFetch.java s^F6sXhyPi
*/ W'w;cy:H
package NetFox; BtS#I[-p_
5q<AMg
Lu!o!>b
import java.io.*; X(Gp3lG
import java.net.*; :,03)[u{8
UN'[sHjOnD
6('2.^8
public class FileSplitterFetch extends Thread { ?zW4|0
Vo^ i7
_oK*1#Rm8
String sURL; //File URL /?<o?IR~6
long nStartPos; //File Snippet Start Position H'E(gc)>)
long nEndPos; //File Snippet End Position $s-/![ 6
int nThreadID; //Thread's ID VWqmqR%
boolean bDownOver = false; //Downing is over .}Va~[0j
boolean bStop = false; //Stop identical f0+)%gO{
FileAccessI fileAccessI = null; //File Access interface &GF@9BXI3
zil^^wT0J
;5qZQ8`4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oUrNz#U
{ Vvk1 D(
this.sURL = sURL; @&(0]kZ6
this.nStartPos = nStart; {2Jo|z
this.nEndPos = nEnd; rnW(<t"
nThreadID = id; rM/Ona2x
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -0rc4<};h
} +~b@W{
qScc~i Oq
9<BC6M_/
public void run() X}*\/(fzl
{ 8UiRirw
while(nStartPos < nEndPos && !bStop) o NX-vN-
{ 2fIHFo\8
/<7'[x<
?7>G\0G
try{ KITC,@xE_O
URL url = new URL(sURL); )Y.H*ca
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [w&B>z=g$
httpConnection.setRequestProperty("User-Agent","NetFox"); .} al s
String sProperty = "bytes="+nStartPos+"-"; +?r,Nn
httpConnection.setRequestProperty("RANGE",sProperty); wWjZXsOd
Utility.log(sProperty); #[$^M:X.
5Fa.X|R~
Fq\vFt|m<
InputStream input = httpConnection.getInputStream(); S"+X+Oxp7?
//logResponseHead(httpConnection); jroR2*
0;9X`z J
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byte[] b = new byte[1024]; r]JV!'R
int nRead; jpijnz{M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @@->A9'L
{ i+rh&,
nStartPos += fileAccessI.write(b,0,nRead); ]\DZW4?'
//if(nThreadID == 1) 4mYJi#e6x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9Z,K
} !R@v\Eu
(55k70>i3
G)~/$EF,_
Utility.log("Thread " + nThreadID + " is over!"); 6! `^}4
bDownOver = true; #Bu W
//nPos = fileAccessI.write (b,0,nRead); h=:Ls]ZU
} FfEP@$
catch(Exception e){e.printStackTrace ();} o@T-kAEf-.
} b]A9$-
} WBc,/lgZ
ux>wa+XFa
->"Z1
//打印回应的头信息 `^_c&y K
public void logResponseHead(HttpURLConnection con) 2z*EamF
{ #6okd*^
for(int i=1;;i++) f8ucJ.{"
{ >#pZ`oPEAv
String header=con.getHeaderFieldKey(i); '0ks`a4q
if(header!=null) E~]37!,\\9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oUSv)G.zb
Utility.log(header+" : "+con.getHeaderField(header)); (rTn6[*
else 3Lg)237&j
break; vGX L'k
} LR`]C]
} *z?Vy<u G
\tCxz(vKz
U+[ p>iP
public void splitterStop() Go;fQ yG
{ GN0s`'#"3%
bStop = true; 3.0t5F<B
} pUV4oyGV
Uw!N;QsC
rJz`v/:|P
} >]dH1@@
P:8qmDXo
v?6g. [;?
/* {wK|C<K
**FileAccess.java czG]rl\1
*//文件访问(定位，写) *3R3C+ L
package NetFox; OV>JmYe1{/
import java.io.*; ;*+wg5|
5EX Ghc'
.#Vup{.
public class FileAccessI implements Serializable{ Al}D~6MD
Sv#S_jh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b=$(`y
RandomAccessFile oSavedFile; UiE 1TD{
long nPos; Bjc<d,]
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Y'&rSHI"
public FileAccessI() throws IOException ,#V}qSKUS
{ !pJd^|4A]
this("",0); 4QZ|e{t
} pB;8yz=
59k[A~)~
XbaUmCuh
public FileAccessI(String sName,long nPos) throws IOException cqd}.D
{ <>71;%e;'
oSavedFile = new RandomAccessFile(sName,"rw"); +eUWf{(_
this.nPos = nPos; Bx" eX>A8
oSavedFile.seek(nPos); (qyT,K8
} u%24% Q
Rlwewxmr
G2 {R5F !
public synchronized int write(byte[] b,int nStart,int nLen) >{1 i8 b@
{ SoJ=[5W
int n = -1; (8Inf_59
try{ &@U)
oSavedFile.write(b,nStart,nLen); -]~KQvIH!
n = nLen; *S= c0
} -\I".8"YE
catch(IOException e) 2~B9 (|
{ ; 8B)J<y
e.printStackTrace (); Oj]4jRew
} ~TfN*0
8?4/
-Cc2|~n
return n; g3*J3I-O
} bAwFC2jO[
}trQ<*D
k:i}xKu
} E``\Jre@
wf""=;
\$Q?
/* qBDhCE
**SiteInfoBean.java .~Gt=F+`s
*/ Vjqs\
package NetFox; |T+YC[T#v
CFW#+U#U
~{00moN"m
public class SiteInfoBean { d`sIgll&n
kE[Hq-J=N
AAc*\K
private String sSiteURL; //Site's URL XCyAt;neon
private String sFilePath; //Saved File's Path f+V^q4
private String sFileName; //Saved File's Name /oC@:7
private int nSplitter; //Count of Splited Downloading File P ~rTuj
=u<jxV9
q]rqFP0C
public SiteInfoBean() e13' dCG
{//nSplitter的缺省值为5 78h!D[6
//default value of nSplitter is 5 %pUA$oUt
this("","","",5); 4NDT5sL
} Wagb|B\
/I~(*X
$,8}3R5}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J/>9w
{ ["BD,mB
sSiteURL= sURL; Xf%wW[~
sFilePath = sPath; zL=PxFw0
sFileName = sName; ,/Al'
this.nSplitter = nSpiltter; s<'WTgy1i
#McX
'9tV-whw
} XJ6=Hg4_O
N?l
b~Un=-@5a
public String getSSiteURL() qk_YFR?R
{ ['_W<
return sSiteURL; (Y~gItej
} FB }8
8Y P7'Fz
c+N\uG4
public void setSSiteURL(String value) hOR1RB
{ xY@<<
sSiteURL = value; J|@kF!6
} ftRzgW);
s0/y> ok
2B[I- K s
public String getSFilePath() 'tJ@+(tqw
{ vC%Hc/&.}
return sFilePath; "7}e~*bM?`
} I'c rH/z9
bF c %
fp2uk3Bm[
public void setSFilePath(String value) WVdF/H
{ [;$9s=:[
sFilePath = value; (dHil#l
} # 5b
6g 5Lf)yG
v{O(}@
public String getSFileName() &H:2TL!
{ k{E!X
return sFileName; v O@7o
} EeDK ^W8N
gT#hF]c:
_Eus7
public void setSFileName(String value) xi}3)5
{ NU(YllPB
sFileName = value; d_)VeuE2
} =@s{H +
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%3es+A@
public int getNSplitter() f<LRM
{ aB2t/ua
return nSplitter; g;\_MbfP
} \!df)qdu
Ak+MREG
g&fq)d
public void setNSplitter(int nCount) <4RP:2#
{ sG:tyvln
nSplitter = nCount; A ^X1
} Dz<vIMLF{
} Q)93+1]
W3]?>sLE*
N(Xg#m
/* kA{eT
**Utility.java E=RX^ 3+}
*/ gi JjE
package NetFox; j7 \y1$w
nrJW.F]S8[
P*3PDa@
public class Utility { f;]C8/W
j)Y68fKK
^wMZG'/
public Utility() x2Dg92
{ 0jMS!"k
zTW)SX_O
Qkx}A7sK
} MOIMW+n
Vy@0Got5=
//线程睡眠 W7?f_E\>W
public static void sleep(int nSecond) I2e@_[ 1
{ Km!~zG7<
try{ NzG] nsw
Thread.sleep(nSecond); *s6(1S
} rk< 3QXv
catch(Exception e) P"<,@Mn
{ Ag_I'
e.printStackTrace (); DUWSY?^c
} aSQvtv)91
} hg+0!DVx
OJXK]dZ
//日志 \>)#cEX5
public static void log(String sMsg) /YD2F
{ #GIjU1-
System.err.println(sMsg); LseS8F/q
} ]C5/-J,F
O"m(C[+[
LNI]IITx/
public static void log(int sMsg) lJdwbuB6
{ ^u$?& #
System.err.println(sMsg); 1wt(pkNk
} >f-*D25f%
} 7|^5E*8/
1Gh3o}z
f/tJ>^N5
/* J:G~9~V^
**TestMethod.java "cx#6Bo|
*/ :qrCqFl
package NetFox; r"x/,!_E
on)$y&lu
UCI !>G
public class TestMethod { \@F!h8e4
9q>rUoK^
@%4tWE
public TestMethod() i3U_G^8
{ ///xx/weblogic60b2_win.exe Ztj~Q9mu
try{ Z=[?Tf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xOBzT&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TY]-L1$
SiteFileFetch fileFetch = new SiteFileFetch(bean); ),&tF_z:
fileFetch.start(); 0/,Dy2h
} +hzS'z)n&
catch(Exception e){e.printStackTrace ();} %TS8 9/
*."a>?D~
Erq%Ck(
} *;Gnod<
d <Rv~F@
GOj<>h}r
public static void main(String[] args) ?@5#p*u0
{ \@hq7:Q
new TestMethod(); X'.*I])
} *k<{nj@y
} GcCMCR3
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