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)); ag$Vgl
} .b\$MZ"(
for(int i=0;i<nEndPos.length-1;i++) 0MV>"aV
{ (]_1
nEndPos = nStartPos[i+1]; ^?$WVB
} vK(i9>;7
nEndPos[nEndPos.length-1] = nFileLength; e'~Zo9`r6
} AGH|"EWG
} g wz7krUTe
1<+2kBuY
*eIJwXE
//启动子线程 'jmTXWq*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +${D
for(int i=0;i<nStartPos.length;i++) D*Ik7Pe
{ fKp#\tCc y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p7);uF^O%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RZ6xdq}>
nStartPos,nEndPos,i); Ys -T0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !(qsD+
fileSplitterFetch.start(); GQ*wc?f3
} z?>D_NLX6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SaC d0. h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ".SJ~`S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Kh(ZU^{n
nEndPos = " + nFileLength); /y A7%2
// fileSplitterFetch[nPos.length-1].start(); !E,A7s
KQ`qpX^d
_8Z_`@0
//等待子线程结束 R-NS,i={
//int count = 0; Q9Uf.Lh2
//是否结束while循环 /D5`
boolean breakWhile = false; ;=geHiQHA
!1n8vzs"c
fR)m%m
while(!bStop) ]BtbWKJBqe
{ 6}4'E
write_nPos(); ak->ML
Utility.sleep(500); z?[r
breakWhile = true; BJgW,huLy
}K1JU`Lz
ikSF)r;*t
for(int i=0;i<nStartPos.length;i++) $BkubWM
{ Glxuz0]
if(!fileSplitterFetch.bDownOver) N;Dni#tQ`
{ z^_*&
breakWhile = false; zS\E/.X2
break; n8uv#DsdK
} \ {qI4=
} xfy1pS.[:
if(breakWhile) _ ):d`O e
break; [vMvV4,
#?*WPq
5nTY ?<x`k
//count++; `(v='$6}
//if(count>4) O=v#{[
// siteStop(); -od!J\KCy
} fbWFLSm;
L f"i !
c~{9a_G
System.err.println("文件下载结束！"); {~h*2n
} .,7JAkB%t
catch(Exception e){e.printStackTrace ();} zUkN 0
} JoRT&rkd
bV edFm
e%4:) IV!;
//获得文件长度 S!Omy:=;i
public long getFileSize() >ELlnE8
{ }"|"Q7H
int nFileLength = -1; e{X6i^% m_
try{ Dfps gY)/?
URL url = new URL(siteInfoBean.getSSiteURL()); YY&l?*M<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S-7'it!1
httpConnection.setRequestProperty("User-Agent","NetFox"); D\@m6=L
h Ggx
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int responseCode=httpConnection.getResponseCode(); Pt@%4 :&-h
if(responseCode>=400) @HRC\OG
{ ,ldI2]
processErrorCode(responseCode); [,K.*ZQi
return -2; //-2 represent access is error CT KG9 T
} VOc8q-hK
<&&SX;
j [rB"N`0
String sHeader; neXeAU
-zp0S*iP7
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for(int i=1;;i++) k% sO 0
{ is1's[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;w6>"O$a
//Utility.log(in.readLine()); }j2Y5
sHeader=httpConnection.getHeaderFieldKey(i); rC.eyq,105
if(sHeader!=null) <V7>?U l
{ VA"*6F
if(sHeader.equals("Content-Length")) Xg=x7\V
{ 6`0mta Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j4>a(
break; e$u4vC~
} zaFt*~@X
} sp7*_&'J
else 'WI^nZM
break; ybeKiv9
} Yly@ww9t|
} \k]x;S<a
catch(IOException e){e.printStackTrace ();} B!dU>0&Ct
catch(Exception e){e.printStackTrace ();} =/u%c!
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V7Z4T6j4
Utility.log(nFileLength); o]ag"Q
t~e<z81p
~_9n.C
return nFileLength; b{d4xU8'
} ) c/% NiN
< -uc."6\
i.xXb[M+
//保存下载信息（文件指针位置） $xOI 1|d
private void write_nPos() )mJf|W!Z#
{ U9&k;`
try{ ?_oF:*~\
output = new DataOutputStream(new FileOutputStream(tmpFile)); [F_/2+e
output.writeInt(nStartPos.length); [97KBoSU
for(int i=0;i<nStartPos.length;i++) e/*$^i+S
{ |.F
// output.writeLong(nPos); j ,)P9V
output.writeLong(fileSplitterFetch.nStartPos); DbZ0e5
output.writeLong(fileSplitterFetch.nEndPos); (faK+z,*6R
} %*o8L6Hn
output.close(); 'qArf
} Bd^"=+c4
catch(IOException e){e.printStackTrace ();} Fhv2V,nZ<
catch(Exception e){e.printStackTrace ();} G/d4f?RU
} Q|,B*b
K*IxUz(
l akp
//读取保存的下载信息（文件指针位置） #Ei,(xiP
private void read_nPos() 6oinidB[l
{ l{:a1^[>y
try{ 8K;Y2 #
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GyW.2
int nCount = input.readInt(); 3;7q`
nStartPos = new long[nCount]; dLvJh#`o
nEndPos = new long[nCount]; =(EI~N
for(int i=0;i<nStartPos.length;i++) X53mzs
{ 4"@GNk~e
nStartPos = input.readLong(); x lsqj`=
nEndPos = input.readLong(); 4g}FB+[u
} R#n%cXc|
input.close(); R*zO dxY
} Y7GF$}%UL
catch(IOException e){e.printStackTrace ();} tp:\j@dB
catch(Exception e){e.printStackTrace ();} >tG+?Y'{
} ? b[n|^wS
,;<RW]r-P
sBK <zR
private void processErrorCode(int nErrorCode) 7 uMd ZpD
{ T*I?9d{k
System.err.println("Error Code : " + nErrorCode); tu>{
} [EY`am8[
nRb^<cZf
c=[q(|+O!
//停止文件下载 a`E*\O'd
public void siteStop() _Cy:]2o
{ #5&jt@NS
bStop = true; .fzu"XAPu
for(int i=0;i<nStartPos.length;i++) kvGCbRC
fileSplitterFetch.splitterStop(); 'r} zY-FM`
<w>/^|]#
?Pwx~[<1""
} D-IR!js ]
} H^~.mBP n
//负责部分文件的抓取 -fgC"2H
**FileSplitterFetch.java ' )-M\'S$E
*/ lFUWV)J\
package NetFox; NQ|xM"MqD
z[#Fog
VW@ x=m
import java.io.*; t` 8!AhOgc
import java.net.*; }wwe}E-e
\aP6_g:N}
`7+j0kV)
public class FileSplitterFetch extends Thread { (QB+%2v
4ZC!SgJo
64j|}wJ$
String sURL; //File URL hzY[ G:
long nStartPos; //File Snippet Start Position sk2%
long nEndPos; //File Snippet End Position Y'`"9Db
int nThreadID; //Thread's ID .wK1El{bf
boolean bDownOver = false; //Downing is over Y\+KoR';
boolean bStop = false; //Stop identical [m'CR 4(|
FileAccessI fileAccessI = null; //File Access interface oc{EuW{Ag
[U\(G
=l942p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d"~(T:=r
{ rrs"N3!aT
this.sURL = sURL; E1Q0k5@
this.nStartPos = nStart; ekQrW%\3
this.nEndPos = nEnd; kw,$NK'
nThreadID = id; Y7U&Q:5'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1;| LI?
} 2GWDEgI1o
b^`AJK
ohc1 ~?3b
public void run() Bmo$5$
{ {hqAnZ@]vr
while(nStartPos < nEndPos && !bStop) :Gh~fm3}
{ ad n|N
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Wv K(G3
try{ {.k)2{
URL url = new URL(sURL); 7;LO2<|1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h<p3'
httpConnection.setRequestProperty("User-Agent","NetFox"); -NM0LTF
String sProperty = "bytes="+nStartPos+"-"; hPdx(E)8!d
httpConnection.setRequestProperty("RANGE",sProperty); H5nS%D
Utility.log(sProperty); ^m7~:=K7WG
xi'<y
8NimZ(
InputStream input = httpConnection.getInputStream(); Mth6-^g5
//logResponseHead(httpConnection); 7w58L:)B.
TYjA:d9YH
=qoRS0Qa
byte[] b = new byte[1024]; 2H[)1|]l
int nRead; ~U}Mv{y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0,FC YTtj$
{ Ie'P#e'
nStartPos += fileAccessI.write(b,0,nRead); o;`!kIQ
//if(nThreadID == 1) QLbMPS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;vO@m!h}U
} 6~5$s1Yc
'pP-rdx
`1p 8C%
Utility.log("Thread " + nThreadID + " is over!"); mVm4fHEYwU
bDownOver = true; Rt= X%[YL
//nPos = fileAccessI.write (b,0,nRead); J(h3]J/Yw
} zTCP)x
catch(Exception e){e.printStackTrace ();} D\]&8w6&
} 5n:71$6[
} ;Gm>O7"|@
r(uP!n1+
(;6s)z
//打印回应的头信息 ,9ml>ji`=
public void logResponseHead(HttpURLConnection con) sms1%%~
{ 8?jxDW a
for(int i=1;;i++) bY#;E;'7
{ _|n=cC4Qu
String header=con.getHeaderFieldKey(i); U6WG?$x
if(header!=null) c<qe[iyt/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VEh]p5D
Utility.log(header+" : "+con.getHeaderField(header)); PHR#>ZD
else +cfziQ$'
break; JmWR{du
} #q4*]qGHm
} =B5E0x
w@N{@tG
fwmLJ5o N
public void splitterStop() 9[>Lp9l'
{ ^o%_W0_r
bStop = true; e)pTC97^L
} Hc!!tbBQ
jmW^`%;7
~Q!~eTw
} 5~\Kj#PBx
q]v,
c2b6B.4
/* _:,.yRez
**FileAccess.java w yD%x(
*//文件访问(定位，写) I#l;~a<9z
package NetFox; >_#)3K1y8
import java.io.*; GAJ~$AiwHH
P06.1
Ve:&'~F2 s
public class FileAccessI implements Serializable{ |(%AM*n
Z% Z"VoxH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ggCr-
RandomAccessFile oSavedFile; T <A
long nPos; ^_w*XV
@aB9%An1
}=pOiILvD
public FileAccessI() throws IOException `!kL1oUYE
{ 7x+=7,BZd
this("",0); FuMq|S
} r } 7:#XQ
Hs<n^fyf
e 2*F;.)
public FileAccessI(String sName,long nPos) throws IOException LV=^jsQ5
{ -R@JIe_28f
oSavedFile = new RandomAccessFile(sName,"rw"); ,^+#M{Z
this.nPos = nPos; 2E$i_jc
oSavedFile.seek(nPos); s*{mT6s+T
} m3%ef
LY1KQuY
ftW{C1,U7
public synchronized int write(byte[] b,int nStart,int nLen) +G\0L_B
{ O2@" w23
int n = -1; v|y<_Ya
try{ 4^MSX+zt
oSavedFile.write(b,nStart,nLen); z6}Pj>1
n = nLen; Uf[T_
} F(G<*lA
catch(IOException e) 3#<'[TF00t
{ y"Ihr5S\
e.printStackTrace (); 9C1b^^Kb
} *?b@>_1K
"0<Sd?Sz
iiehrK&T!
return n; l)iv\j
} %30T{n:
I W8.
g?$e^ls
} z-)*Q
7n<#y;wo
}RDb1~6C
/* Z3I L8
**SiteInfoBean.java xK=J.>h3
*/ IPkA7VhFF
package NetFox; ~e+0c'n\
IF$^0q
'@S,V/jy0z
public class SiteInfoBean { HD~jU>}}
J,`_,T
j`+0.Zlq
private String sSiteURL; //Site's URL 1O- E],
private String sFilePath; //Saved File's Path v?%0~!
private String sFileName; //Saved File's Name Flne=ij6g
private int nSplitter; //Count of Splited Downloading File uJm#{[
&:C{/QnA
3P3:F2S R
public SiteInfoBean() `L+~&M
{//nSplitter的缺省值为5 bA0uGLc
//default value of nSplitter is 5 xan/ay>
this("","","",5); &,_?>.\[<
} qU}lGf!dVn
hQP6@KIe)
o9~h%&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `6n!$Cxo
{ qYDj*wqf
sSiteURL= sURL; PGMv(}%;
sFilePath = sPath; % Mw'e/?
sFileName = sName; T&mbXMN
this.nSplitter = nSpiltter; e%'z=%(
vx PDC~3;
q!9^#c
} @OBHAoz%/
J]$er0`LY
)Xq@v']%~9
public String getSSiteURL() HgS<Vxmq
{ 65;|cmjv
return sSiteURL; /kAwe *)
} BQ5_s,VM
(q~R5)D
V>1D1
public void setSSiteURL(String value) XTIu(f|d_;
{ JgxE|#*7U
sSiteURL = value; L,yA<yrC
} 'E@2I9Kj
uT'-B7N
#: dR^zr<
public String getSFilePath() C,9)V5!tP2
{ B#| Z`mZ
return sFilePath; :Pj W:]
} g?w2J6Z.`J
u'#`yTB6b
uDpf2(>s
public void setSFilePath(String value) 87&KQ_
{ ev)rOcOU
sFilePath = value; 7W6eiUI'
} `4$4bXrP'
D)f5pEq'
MT;SRAmUr
public String getSFileName() 6#OL ;Y]_
{ k'6<jEbk
return sFileName; Fl8w7LcF7
} 2]?w~qjWm
/ c4;3>IS
!G+n"-h9'
public void setSFileName(String value) aW52.X z%8
{ j|3g(_v4W
sFileName = value; o+]Y=r2
} CpUI|Rs
D{Hh#x8Y
^zBjG/'7
public int getNSplitter() bEVO<x+
{ '*o7_Ez-{
return nSplitter; bd@*vu}?}
} %s~NQ;Y
N1D6D$s0
ORV}j,Ym
public void setNSplitter(int nCount) V%X:1 8j
{ c^i"}2+
nSplitter = nCount; 3bT6W,J4T
} [[";1l
} ;zfQ3$@9
< fojX\}3
Fw(b1d>E
/* ZXFAuF
**Utility.java &:!ZT=
*/ &4w\6IR
package NetFox; V6DBKq
XgwMppacw
6Tm Rc
public class Utility { \;3B?8wbIl
;'2`M
3i@ "D
public Utility() $V`KrA~]
{ 1YF+(fk
0U>t>&,"
>z fq*_
} ::3iXk)
kg/+vJ
//线程睡眠 y(aAp.S>
public static void sleep(int nSecond) )[@YHE5g
{ Z@>=&
try{ 7yqSt)/U
Thread.sleep(nSecond); I =tyQ`
} =Do3#Xe2V
catch(Exception e) 2$j Ot}
{ F_p3:l
e.printStackTrace (); &;~2sEo,
} p]1yd;Jt
} Ef,7zKG
v -|P_O&z
//日志 QoT3;<r}
public static void log(String sMsg) h a,=LV
{ 4."o.:8x
System.err.println(sMsg); U- *8%>Qp
} n!l./>N
g "K#&
jE?\Yv3
public static void log(int sMsg) Y^94iOk%T
{ (_i vN
System.err.println(sMsg); )$l9xx[
} 7 BnenHD
} .%J?T5D
U'Ja\Ek/f
I\Gp9w0f
/* d0H
**TestMethod.java \CJx=[3(
*/ ; $ ?jR c
package NetFox; c`$`0}
c:@OX[##
UpszCY4
public class TestMethod { UgD'Bi
:9!0Rm
V&4:nIS>z
public TestMethod() U Qi^udGFD
{ ///xx/weblogic60b2_win.exe uJ)=+Exii
try{ Y|0-m#1F#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q563,s
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >Xh(`^}SQ*
SiteFileFetch fileFetch = new SiteFileFetch(bean); avxn}*:X.
fileFetch.start(); U$/Hp#~X
} e>vUkP y
catch(Exception e){e.printStackTrace ();} Hh/ -^G
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CtC`:!Q
} ?`l=!>C4s
4MtqQq4%
c~L6fvS
public static void main(String[] args) ~&[P` Z$
{ PkCeV]`w
new TestMethod(); Hdq/E>u
} U@v8H!p^i
} Y?vm%t`K
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