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^t%p1R
} DlCN
for(int i=0;i<nEndPos.length-1;i++) Wo&22,EB
{ +I5\`By=
nEndPos = nStartPos[i+1]; X8Z) W?vu
} QDYuJ&!h
nEndPos[nEndPos.length-1] = nFileLength; C2rG3X^~Jm
} S\N l|U[
} " J9
5fk A?Ecqq
j7&#R+f
//启动子线程 M**Sus87Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gD)M7`4
for(int i=0;i<nStartPos.length;i++) s3A(`heoq
{ 9U<WR*H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S>x@9$( ym
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "vybVWEE
nStartPos,nEndPos,i); &M@ .d$<C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |GQq:MB;z
fileSplitterFetch.start(); W gyRK2#!
} `?=3[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A nl1+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]*a(^*}A%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0O'M^[=d.8
nEndPos = " + nFileLength); #0r^<Yn
// fileSplitterFetch[nPos.length-1].start(); {'zS8
)XonFI
r&R~a9+)
//等待子线程结束 )R `d x
//int count = 0; UUWRC1EtI
//是否结束while循环 >b\|%=(x!*
boolean breakWhile = false; v0) %S
E!}'cxb^
g0biw?
while(!bStop) fsOlg9
{ PtuRXx
write_nPos(); BDfMFH[1
Utility.sleep(500); 90+Vw`Gz=
breakWhile = true; /'{vDxZf R
<fBJ@>
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for(int i=0;i<nStartPos.length;i++) [K #$W
{ XO?WxL9k]
if(!fileSplitterFetch.bDownOver) +?6]Vu&|f
{ SPb`Q"
breakWhile = false; g~21|Sa$[
break; /xgC`]-
} y'>9'/&
} OcF_x/#
if(breakWhile) bl!pKOY
break; l5^Q
Yl au
W<&/5s
//count++; 5KB Z-,
//if(count>4) nWCJY:q;5
// siteStop(); n+=7u[AZi
} ).,twf58
<k1muSe
Yqh-U%"'
System.err.println("文件下载结束！"); ES,JdImZ|
} k"[AV2UW1
catch(Exception e){e.printStackTrace ();} *fi`DiO
} ,.{M1D6'R`
W="pu5q$5
rJf{YUZe
//获得文件长度 BPW.&2?<
public long getFileSize() @)Vb?|3
{ nO6UlY
int nFileLength = -1; 2va[= >_
try{ p?Ux1S
URL url = new URL(siteInfoBean.getSSiteURL()); ]{i0?c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =zAFsRoD_B
httpConnection.setRequestProperty("User-Agent","NetFox"); ?8grK
=\8 x
)$Ib6tYY
int responseCode=httpConnection.getResponseCode(); ]Y$Wv9S6
if(responseCode>=400) nO`[C=|
{ ^WWr8-
processErrorCode(responseCode); s +S6'g--
return -2; //-2 represent access is error W)Y-^i5
} #('R`~
8yI4=P"F,
^K[xVB(&
String sHeader; ]Y?ZUSCJ
-|#/KKF
JK{2hr_a
for(int i=1;;i++) y<IHZq`C3
{ L6qK3xa}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L1lDDS#
//Utility.log(in.readLine()); E}w5.1
sHeader=httpConnection.getHeaderFieldKey(i); ;gHcDnH)
if(sHeader!=null) e"EGqn&!
{ Qj [p/H$
if(sHeader.equals("Content-Length")) JUGq\b&m
{ 0"@J*e#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QN#Lbsd
break; ?zsRs?rc0
} 3:sc%IDP
} 1A;,"8kBd
else A Ef@o+A
break; ]_s;olKNI
} HIj:?y
} o|84yT!~
catch(IOException e){e.printStackTrace ();} A0.xPru1p
catch(Exception e){e.printStackTrace ();} ={h^X0<s9
CO ZfR~}
JeVbFZ8
Utility.log(nFileLength); wuCZz{c7
PCDvEbpG
'q/C: Yo
return nFileLength; w5-^Py
} ~ c~j
P-^-~/>n
Lo[;{A$u
//保存下载信息（文件指针位置） ='Oxy
private void write_nPos() .d#Hh&jj
{ 92,@tNQQ}
try{ (ux9"r^g;x
output = new DataOutputStream(new FileOutputStream(tmpFile)); ga1b%5]v.
output.writeInt(nStartPos.length); ZS3T1 <z
for(int i=0;i<nStartPos.length;i++) o+^e+ptc
{ +N~{6*@uz,
// output.writeLong(nPos); ^LSD_R^N
output.writeLong(fileSplitterFetch.nStartPos); \ X6y".|-
output.writeLong(fileSplitterFetch.nEndPos); zuJ` 704
} GXv2B%i8
output.close(); [m x}n+~
} - 3<&sTR
catch(IOException e){e.printStackTrace ();} /'v!{m
catch(Exception e){e.printStackTrace ();} `x L@%
} yYaYuf
)zP"Uuu
Z>NA 9:
//读取保存的下载信息（文件指针位置） F')E)tV
private void read_nPos() \"yR[.Q?
{ T sJ71
try{ /3"S_KE1@+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &7,/^ >">
int nCount = input.readInt(); M-!#-l
nStartPos = new long[nCount]; Z +<Y.*6
nEndPos = new long[nCount]; :w4H$+j
for(int i=0;i<nStartPos.length;i++) ,:81DA
{ $Ixd;`l*
nStartPos = input.readLong(); da8 R.1o
nEndPos = input.readLong(); ~Ty6]A
} 4g.S!-H@R
input.close(); S[rfcL"
} A}"uEk(R
catch(IOException e){e.printStackTrace ();} oY@]&A^ah
catch(Exception e){e.printStackTrace ();} m1p%,
} hB:+_[=Kj.
K^I$05idi
)gR3S%Ju
private void processErrorCode(int nErrorCode) dt>!=<|k
{ Z%-uyT@a
System.err.println("Error Code : " + nErrorCode); 6|Rj YX
} brn>FFAwO
@:9mTP7
gr>FLf
//停止文件下载 R,zp&L
public void siteStop() 4 >D5t)254
{ fG7-07
bStop = true; PO2]x:
for(int i=0;i<nStartPos.length;i++) r7)iNTQ1
fileSplitterFetch.splitterStop(); E?mW4?
.e:+Ek+
NXE1v~9V
} "yXqf%CGE
} Y}x_ud,
//负责部分文件的抓取 zWdz9;=_
**FileSplitterFetch.java m]\d9%-AT&
*/ OL&VisJ{75
package NetFox; NL ceBok
0g@*N4
RQn3y-N]
import java.io.*; 7nPm{=BG
import java.net.*; wi:d!,P`e
wK%x|%R[
tkix@Q!;\
public class FileSplitterFetch extends Thread { 9+>%U~U<
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k.F(*kh
String sURL; //File URL IZ_ B $mo
long nStartPos; //File Snippet Start Position 9l7 youZ]
long nEndPos; //File Snippet End Position Q[Tbdc%1EG
int nThreadID; //Thread's ID Nk>6:Ho{G
boolean bDownOver = false; //Downing is over ZOzyf/?.
boolean bStop = false; //Stop identical w?c~be$
FileAccessI fileAccessI = null; //File Access interface 4_Rv}Yd
&-Z#+>=H(
:Z5kiEwYM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >LB x\/
{ h6Hop mWVx
this.sURL = sURL; odq3@ ziO
this.nStartPos = nStart; l_=kW!l
this.nEndPos = nEnd; <gr2k8m6$
nThreadID = id; m9m~2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z;i4F.p
} x\(yjNZH
TGPHjSZ1
7o M]qLF
public void run() q/YO5>s15
{ =0mGfTc
while(nStartPos < nEndPos && !bStop) o Bp.|8-
{ 5s2/YG=
>5]w\^QN9_
!]WC~#|{B
try{ 4>[tjz.?k
URL url = new URL(sURL); B.[5N;c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ["?WVXCF8|
httpConnection.setRequestProperty("User-Agent","NetFox"); < 'qtqUL\
String sProperty = "bytes="+nStartPos+"-"; kI$p~
httpConnection.setRequestProperty("RANGE",sProperty); M7IQJFra
Utility.log(sProperty); DWJkN4}o
qT_E=)1
2$QuR~
InputStream input = httpConnection.getInputStream(); t!vlZNc
//logResponseHead(httpConnection); x1*@PiO,.
Z{.L_]$I
D61e
byte[] b = new byte[1024]; ,}42]%$G
int nRead; 9]/ju
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W.U|mNJ$
{ \~q cYp
nStartPos += fileAccessI.write(b,0,nRead); o!t1EPJE*
//if(nThreadID == 1) -wV0Nv(V8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 38q0iAH
} 3H47 vm(`
[ w1"
\8X8NCM
Utility.log("Thread " + nThreadID + " is over!"); h!>NS ?X7
bDownOver = true; \\~4$Ai[
//nPos = fileAccessI.write (b,0,nRead); t]%!vXo
} kOuQR$9s
catch(Exception e){e.printStackTrace ();} ^l/$ 13=
} }u7&SU
} q&wXs/$a
\it<]BN
,o j\=2
//打印回应的头信息 u~d&<_Z
public void logResponseHead(HttpURLConnection con) DK;/eZe
{ OECXNx
for(int i=1;;i++) X{riI^(
{ <ByDT$E_
String header=con.getHeaderFieldKey(i); IN9o$CZ:
if(header!=null) MRHkQE+K@8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P1l@K2r
Utility.log(header+" : "+con.getHeaderField(header)); #[#dc]D
else KBFAV&
break; DWH)<\?
} S\UM0G}v
} k||DcwO
I2=Kq{
RsDI7v
public void splitterStop() #8d$%F))
{ &^YY>]1Py
bStop = true; ,/>~J]:\;
} b511qc"i>M
57b;{kl
VI`x fmVOQ
} way-Q7
X_eV<]zA+
|"Oazll
/* MPd#C*c
**FileAccess.java /_554q
*//文件访问(定位，写) Lsozl<@
package NetFox; %rRpUrnm
import java.io.*; 5+O#5"v_
4[&6yHJ^
6l$o^R^D
public class FileAccessI implements Serializable{ '17u Wq
rbP3&L
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yx}Z:t
RandomAccessFile oSavedFile; .ODtduURe
long nPos; =;$&:Zjy/%
kB]|4CG{
n%<.,(.(S
public FileAccessI() throws IOException zj;y`ENj
{ F<w/@.&m
this("",0); &,&oTd.
} vP'R7r2Yx
3-8Vw$u
{UYqRfgbZ
public FileAccessI(String sName,long nPos) throws IOException uyG4zV\h*
{ $P@P}%2
oSavedFile = new RandomAccessFile(sName,"rw"); t5N4d
this.nPos = nPos; |R*fw(=W
oSavedFile.seek(nPos); _H8)O2mJ
} +o/;bm*U<K
O'-lBf+<
1|cmmUM-'v
public synchronized int write(byte[] b,int nStart,int nLen) u-k?ef
{ {+t'XkA
int n = -1; ~ab"q%
try{ *qBMt[a
oSavedFile.write(b,nStart,nLen); Qzh:*O
n = nLen; R/O_*XY
} 1ck2Gxn
catch(IOException e) W^+bgg<.
{ =8dCk\/
e.printStackTrace (); R4JO)<'K&
} l>&)_:\
a4: PufS
e:V,>RbC0s
return n; ]@?3,N
} tXKhkt`
y9)l,@D
Qw5M\
} C.(ZXU7
`?6m0|\@
L6A6|+H%E
/* y~S[0]y>
**SiteInfoBean.java <qRw! 'S^
*/ `g :<$3}
package NetFox; u%[*;@;9+
jv|IV
kxUGd)S
public class SiteInfoBean { LbYI{|_Js
>LU*F|F]B
[bOy,^@4
private String sSiteURL; //Site's URL >PGm}s_
private String sFilePath; //Saved File's Path |_=jXf\TL
private String sFileName; //Saved File's Name zPkg3H
private int nSplitter; //Count of Splited Downloading File 0`ib_&yI
X}usyO'pW
7_Q86o
public SiteInfoBean() xZhD6'Zzz
{//nSplitter的缺省值为5 5^d%+*l;q
//default value of nSplitter is 5 s_*eX N
this("","","",5); &gEu%s^wR
} Vd1K{rH#
y?unI~4tC
7T2W%JT-,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "+Qh,fTt
{ #/jHnRrQ
sSiteURL= sURL; q2<J`G(tZ
sFilePath = sPath; 7R2)Klt
sFileName = sName; 9vj:=,TNu
this.nSplitter = nSpiltter; R&alq
4*9Dh
F#<PFT4i
} .$OInh
1)PR]s:-m@
ntkinbbD
public String getSSiteURL() bA^a@ lv a
{ z vYDE]
return sSiteURL; n `Xz<Q!
} 2E1TJ.[BS
=91'.c<
vaxg^n|v9
public void setSSiteURL(String value) G[^G~U\+!
{ V[bc-m
sSiteURL = value; \S@A /t6pa
} N7jRdT2k%
x> q3w# B
`k\1vum
public String getSFilePath() mcXakWmi
{ q7PRJX
return sFilePath; Z{CL!
} jI V? p
/&|pXBY$;
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public void setSFilePath(String value) LK%B6-;~-
{ =Ffq =<
sFilePath = value; X}=f{/\S
} xXYens}
B*AMo5
w:LCm `d
public String getSFileName() 4>Y\2O?**
{ &B85;
return sFileName; ,6bMfz
} JS:lysu
D7(t6C=FP
xq)/QR
public void setSFileName(String value) Zll^tF#
{ zn x_p/V
sFileName = value; 0X-2).nu
} \O?B9_
stG&(M
&sgwY
public int getNSplitter() *u>\&`h=
{ 3.H-G~
return nSplitter; ;E"mB4/)
} 8JrGZ8Q4RM
!491 \W0ZH
W9Lg}[>:)
public void setNSplitter(int nCount) V<pqc&f.
{ -Mvw'#(0
nSplitter = nCount; vWovR`
} htRZ}e
} Pb;`'<*U
F)5Aq H/p
79x9<,a)
/* 7x]nY.\
**Utility.java {4 d$]o0V
*/ 4<K`yU]"
package NetFox; "poTM[]tZ7
=4 H K
bx^EaXj(r
public class Utility { fYjsSUnf
]."c4S_)|
W>bW1h
public Utility() kw~H%-,]
{ $Ig,cTR.b
S:uEK
SkA'+(
} XXcf!~uO
EXcjF
//线程睡眠 xi\RUAW
public static void sleep(int nSecond) wIj2 IAD
{ E<SEFn
try{ G0>Wk#or
Thread.sleep(nSecond); IyN9 +
} Y]K]]Ehp
catch(Exception e) CEq]B:[IC
{ Kc\'s65.]
e.printStackTrace (); {:X];A$
} ,O)\,tg
} TkoXzG8yE<
3/=QZ8HA&-
//日志 jFTV\|C
public static void log(String sMsg) 26VdRy{[
{ 2H+DT-hK
System.err.println(sMsg); :t S"sM
} WGluY>C;
ee^_Dh4
:*'?Ac ?
public static void log(int sMsg) :+Ax3
{ _5w?v~65
System.err.println(sMsg); N:[;E3?O
} 5)5bt q)[
} M9g\/]Io;
PjW+V`
c\{}FGC
/* C'2 =0oou
**TestMethod.java Pq>[q?>?
*/ I 47GQho
package NetFox; HHTsHb{7
U hhmG+
XWQ0V
public class TestMethod { >#U<#
i!oj&&
dKQV4dc>
public TestMethod() DjzBG*f/
{ ///xx/weblogic60b2_win.exe o[[r_v_d
try{ r{R7"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "HfU,$[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L{A-0Ffh
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]</4#?_
fileFetch.start(); +()t8,S,
} ^MHn2Cv/~
catch(Exception e){e.printStackTrace ();} *Yu\YjLPG
-yQ\3wli`
^r_lj$:+$
} LA`VqJ
[ky6E*dV`
![]I%'s
public static void main(String[] args) )c >B23D
{ <ii1nz
new TestMethod(); E5BgQ5'
} 'b?.\Bm;
} |z]2KjF&w-
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