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)); 3_ly"\I\
} ZZn$N-
for(int i=0;i<nEndPos.length-1;i++) PU,%Y_xR
{ Mbp7%^E"A
nEndPos = nStartPos[i+1]; 6CCm1F{`
} ]h?q1
nEndPos[nEndPos.length-1] = nFileLength; 5-hnk' ~
} /%mT2
} e\em;GTy
/9e?uC6
byFO^pce
//启动子线程 \xlG3nz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lSg[7lt
for(int i=0;i<nStartPos.length;i++) _U_O0@xi
{ _%[po%]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 31~nay15
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >%ovL8F
nStartPos,nEndPos,i); :r(dMU3%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZTibF'\5N
fileSplitterFetch.start(); kO5lLqE
} aeISb83Y|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GsmXcBzDw2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <.mH-Y5i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g)5mr:\
nEndPos = " + nFileLength); CLTkyS)C
// fileSplitterFetch[nPos.length-1].start(); oOLey!uZw
rlaeqG
ae2Q^yLA
//等待子线程结束 &JXb) W
//int count = 0; |his8\C+x
//是否结束while循环 0,nz*UDk
boolean breakWhile = false; XZ . T%g
p#CjkL
tYXE$i
while(!bStop) ESNI$[`
{ *f3StX
write_nPos(); ^DN:.qQ
Utility.sleep(500); o K>(yC[
breakWhile = true; jQ,Vs=*H
x9,jXd
{"+M%%`*#
for(int i=0;i<nStartPos.length;i++) \"1>NJn&k)
{ j)2I+[aoB
if(!fileSplitterFetch.bDownOver) <)p.GAZ
{ r=&,2meo
breakWhile = false; 59O-"Sc[
break; >v%js!`f
} ?+))J~@t
} kzjuW
if(breakWhile) Jup)A`64
break; +]s,VSL5`
@uH!n~QV
!uQT4<g
//count++; Bz<hP*.O
//if(count>4) ]bJz-6u#:
// siteStop(); 6,A|9UX=`
} \4L ur
{YgU23;q
{2h*NFp
System.err.println("文件下载结束！"); R>*z8n
} V6X )L>!xx
catch(Exception e){e.printStackTrace ();} VD$5 Djq
} ;NR|Hi]
lcie6'<
N#K)Z5J)b
//获得文件长度 8u2k-_9
public long getFileSize() GLn=*Dh#
{ Zp>v
int nFileLength = -1; 3uocAmY
try{ x%l(0K
URL url = new URL(siteInfoBean.getSSiteURL()); ? `p/jA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {+WBi(=W
httpConnection.setRequestProperty("User-Agent","NetFox"); M bWby'
b^VRpv
J, -.5
int responseCode=httpConnection.getResponseCode(); Hw o _;fV
if(responseCode>=400) UZI:st
{ sfyLG3$/
processErrorCode(responseCode); 6sBt6?_T
return -2; //-2 represent access is error >$JE!.p%o
} Y"H`+UV
|%C2 cx
]SCHni_
String sHeader; gz~oQ l)zJ
J'}+0mln
bzFac5n)Q
for(int i=1;;i++) <D/K[mz-
{ |9jK-F6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J8emz8J
//Utility.log(in.readLine()); LDr?'M!D
sHeader=httpConnection.getHeaderFieldKey(i); $@L;j
if(sHeader!=null) 0vqVE]C
{ DyN[Yp|V
if(sHeader.equals("Content-Length")) `;j1H<L
{ Ddr.6`VJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6Qkjr</
break; tnJ7m8JmC
} NV* 2
} f)*?Ji|5F
else <D.E.^Y
break; \6|y~5Hw{r
} WqA)V,E
} K=N&kda
catch(IOException e){e.printStackTrace ();} 9<u&27.
catch(Exception e){e.printStackTrace ();} m^QoB
cb^IJA9}
C~h#pAh
Utility.log(nFileLength); F_qApyU,7
nLm'a_
epsRv&LfC
return nFileLength; nX (bVT4i
} H1k)ya x4_
P8YnKyI,.
rN&fFI
//保存下载信息（文件指针位置） }!iopu
private void write_nPos() 6>WkisxG
{ (2;Aqx5i
try{ 5;XC!Gz
output = new DataOutputStream(new FileOutputStream(tmpFile)); c,r6+oX
output.writeInt(nStartPos.length); >V^8<^?G
for(int i=0;i<nStartPos.length;i++) <9]"p2
{ k M/:n
// output.writeLong(nPos); fz|*Plv
output.writeLong(fileSplitterFetch.nStartPos); 5S4Nx>
output.writeLong(fileSplitterFetch.nEndPos); ^VYR}1Mw
} &E]) sJ0
output.close(); fQ9af)d
} Q,.dIPla
catch(IOException e){e.printStackTrace ();} TIp\-
catch(Exception e){e.printStackTrace ();} vu.ug$T
} RhJ3>DL
\;-Yz
aUMiRm-
//读取保存的下载信息（文件指针位置） Xn"#Zy_
private void read_nPos() d[h=<?E5
{ !*c%Dj
try{ $D`Kz*/.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '@24<T]
int nCount = input.readInt(); W _[9
nStartPos = new long[nCount]; mg*iW55g
nEndPos = new long[nCount]; :30daKo
for(int i=0;i<nStartPos.length;i++) d*TH$-F!p
{ %;wDB2k*
nStartPos = input.readLong(); %{ U (y#
nEndPos = input.readLong(); hzAuj0-A
} F~v0CBcAL
input.close(); t,Tq3zB
} AIP0PJI3
catch(IOException e){e.printStackTrace ();} C,ldi"|
catch(Exception e){e.printStackTrace ();} VnN(lJ
} ;-i)}<
}G(#jOYk
ZXhNn<
private void processErrorCode(int nErrorCode) =glG |
{ *[>{9V
System.err.println("Error Code : " + nErrorCode); +v%+E{F$+
} ([m4dr
6oWFjeZ0
]@_|A, ]
//停止文件下载 Z2;~{$&M+
public void siteStop() P=_W{6
{ N/C$8D34
bStop = true; kJ* N`=
for(int i=0;i<nStartPos.length;i++) )3F}IgD
fileSplitterFetch.splitterStop(); h1'm[Y
nF-l4=
(;Bh7Ft
} S!-t{Q+j^
} 87pu\(,'
//负责部分文件的抓取 4[Ko|
**FileSplitterFetch.java {#=o4~u%;H
*/ (Rs;+S
package NetFox; a'q&[08
t%y i3
s4Jy96<
import java.io.*; 6d5q<C_3t
import java.net.*; ^Ux.s Q
zl, Vj%d
ra ,.vJuT
public class FileSplitterFetch extends Thread { B&(/,.
eiA$) rzy
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String sURL; //File URL 2L.6!THG
long nStartPos; //File Snippet Start Position ocS}4.a@
long nEndPos; //File Snippet End Position Dl?:Mh
int nThreadID; //Thread's ID 1n)YCSA
boolean bDownOver = false; //Downing is over ?>R(;B|ER
boolean bStop = false; //Stop identical )*}?EI4.
FileAccessI fileAccessI = null; //File Access interface Dz$dJF1 8
&?j\=%
p`"Ic2xPJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qus%?B{b}
{ 1Si$Q
this.sURL = sURL; P#:nXc$
this.nStartPos = nStart; 9+Wf*:*EW
this.nEndPos = nEnd; Tj2pEOu
nThreadID = id; 5o^\jTEl^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z0 c|;
} %4wHiCOg
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public void run() O^~nf%
{ I 'ha=PeVn
while(nStartPos < nEndPos && !bStop) S2 -J1x2N
{ TD/ 4lL~(x
b. :2x4
gP!k[E,Q8
try{ `Gg,oCQg
URL url = new URL(sURL); a3[,3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]~pM;6Pu0
httpConnection.setRequestProperty("User-Agent","NetFox"); %mS>v|
String sProperty = "bytes="+nStartPos+"-"; Sq`Zuu9t
httpConnection.setRequestProperty("RANGE",sProperty); K7,Sr1O `
Utility.log(sProperty); OP``+z>
GCrsf
(Kw%fJT
InputStream input = httpConnection.getInputStream(); +WCV"m
//logResponseHead(httpConnection); =Nz;R2{@
Xk:_aJ
z|<?=c2P
byte[] b = new byte[1024]; %y+v0.aWH+
int nRead; Rf!$n7& \
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Tog'3k9Uw
{ p3IhK>
nStartPos += fileAccessI.write(b,0,nRead); IRsyy\[kp8
//if(nThreadID == 1) dFk$rr>q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^HWa owy=
} nKch:g
^aqBL
F ^)( 7}ph
Utility.log("Thread " + nThreadID + " is over!"); Vo(bro4ZQi
bDownOver = true; G4EuW *~
//nPos = fileAccessI.write (b,0,nRead); i@ehD@.dH
} LKM;T-
catch(Exception e){e.printStackTrace ();} fHgvh&FU
} \ Ju7.3.
} C:vVFU|4
' $"RQ=
3oApazH*
//打印回应的头信息 5?>ES*
public void logResponseHead(HttpURLConnection con) K#x|/b'5d
{ % 3<7HY]~
for(int i=1;;i++) m :2A[H+
{ cJ'OqV F
String header=con.getHeaderFieldKey(i); I(qFIV+HR
if(header!=null) R-Gg= l5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ugs9>`fF&
Utility.log(header+" : "+con.getHeaderField(header)); mv#*%St5
else +-Z `v
break; d*LW32B@
} =F46v{la
} ` c"
Ed1y%mR>
6P02=
public void splitterStop() FlT5R*m
{ wB"`lY
bStop = true; bg^<e}{<H
} !d1a9los
5Rae?*XH
!9_'_8
} `r&]Ydu:
h*\u0yD)
>LW}N!IBy
/* L fZF
**FileAccess.java C40o_1g
*//文件访问(定位，写) ]&X}C{v)G
package NetFox; ">vi=Tr
import java.io.*; ur[^/lxx0
FzG>iC}
-[[(Zx
public class FileAccessI implements Serializable{ M<P8u`)>4H
!i\ gCLg2_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y;kiU
RandomAccessFile oSavedFile; xcH&B%;f
long nPos; I5ZM U
mB"1QtD
6!wk5#
public FileAccessI() throws IOException 664D5f#EJ
{ wYQEm
this("",0); $CZ'[`+
} ?@;#|^k9
%Rk DR
ygQe'S{!S\
public FileAccessI(String sName,long nPos) throws IOException `UTUrM
{ 5<YL^m{/L
oSavedFile = new RandomAccessFile(sName,"rw"); n/S+0uT
this.nPos = nPos; "<LWz&e^^
oSavedFile.seek(nPos); gyuBmY
} /@I`V?Q!a
JX{_,2*$
"uFwsjz&B
public synchronized int write(byte[] b,int nStart,int nLen) ',/2J0_
{ lSc=c-iOv
int n = -1; iUk#hLLC
try{ tHK>w%|\R
oSavedFile.write(b,nStart,nLen); zjOOEvi
n = nLen; B<0Kl.V
} Y=5P=wE
catch(IOException e) [v\m)5
{ h J0U-m
e.printStackTrace (); ?wFL\C
} "lSh4X
`46z D ?
T"<)B^8f
return n; 'by+hXk
} @0d"^
dCeLW
3#Bb4\_v
} 8:>V'j
eze%RjO}
gd*2*o$g(
/* eTuKu(0 E
**SiteInfoBean.java fP\q?X@]E
*/ ,Vw>3|C
package NetFox; w ?*eBLJ(G
ZvMU3])u
N$x&k$w R
public class SiteInfoBean { EC 1|$Co
)Yv=:+f
?^W1WEBm
private String sSiteURL; //Site's URL &{UqGD#1&
private String sFilePath; //Saved File's Path B(ktIy
private String sFileName; //Saved File's Name *UJ4\
private int nSplitter; //Count of Splited Downloading File tRZ4\Bu
G]4Ca5;Z!N
Qd{8.lB~LQ
public SiteInfoBean() b $JS|
{//nSplitter的缺省值为5 ]Yw$A
//default value of nSplitter is 5 gdA2u;q
this("","","",5); x~vNUyEN)
} ],k~t5+
O9ps?{g
JO+tY[q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }ML2-k
{ E6ZkO/
sSiteURL= sURL; =$fz</S=J
sFilePath = sPath; ]%FAJ\
sFileName = sName; gXJBb+P
this.nSplitter = nSpiltter; N+@ Ff3M
owQ,op#
3h d30o
} ?5J#
^9:`D@Z+
.<F46?HS
public String getSSiteURL() bXOKC
{ O~6%Iz`
return sSiteURL; UaF~[toX
} OtmDZ.t;`
d]`6N
|w}j!}u
public void setSSiteURL(String value) CV.|~K0O
{ ws+'*7
sSiteURL = value; 2&>t,;v@
} d#a/J.Z$A
N=KtW?C
7I XWv-
public String getSFilePath() zMFTkDY
{ jDpA>{O[
return sFilePath; H3<tsK=:
} uR5+")r@S
R~kO5jpW
(.cA'f?h
public void setSFilePath(String value) :J]'c}
{ jRU:un4
sFilePath = value; w\o6G7
} $t):r@L
AX8~w(sv
p%>sc
public String getSFileName() fq6Obh=A#
{ 6r<a
return sFileName; 5 ix*wu`,
} U 5J _Y
<v|"eq}
eV|N@
public void setSFileName(String value) k773h`;
{ 'NhQBk
sFileName = value; I"88O4\@
} FT-.gi0
eyDV911
=#Sw.N
public int getNSplitter() z_$c_J
{ UJI2L-;Ul
return nSplitter; E{u6<B*
} LUMbRrD-
O D}RnKL
q>2bkcGY#
public void setNSplitter(int nCount) uGMzU&+
{ \dtiv&x
nSplitter = nCount; u]IbTJ'
} \N*([{X
} wc;n= %
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.d1ff];
/* (4+P7Z,Nc
**Utility.java ,IjZQ53q~
*/ $9,&BW_*
package NetFox; M,]|L ch
10FiA;
]$@a.#}
public class Utility { =b%}x >>
6eV#x%z@v'
2|je{
public Utility() AEyvljv
{ XDemdMy$
8F}drK9>F
YZg#H)w%
} |sZqqgZ-
~5N}P>4*
//线程睡眠 l{k_;i!D
public static void sleep(int nSecond) Y$=jAN
{ D<SC `
try{ =u<:'\_
Thread.sleep(nSecond); p~$cwbQ!
} DzAZv/h76
catch(Exception e) 4@PA+(kvS
{ yH/A9L,Z
e.printStackTrace (); yajdRU
} RxP H[7oZ
} -'&/7e6>y
%j7b0pb
//日志 <Y]LY_(
public static void log(String sMsg) 3z8i0
{ X94a
System.err.println(sMsg); C-&ymJC|
} w' 7sh5
<`}P
/WuYg OI
public static void log(int sMsg) ~non_pJ
{ &9yZfp
System.err.println(sMsg); I!sT=w8V
} _'=,c"
} C96/
IO%kXF.[
jeC=s~
/* 0fsVbC
**TestMethod.java @5>#<LV=E#
*/ #<*Vc6pC
package NetFox; 39X~<\&'
FdU]!GO-X
s2<!Zb4
public class TestMethod { GK@OdurAR
MEDh
'cD?0ou`o
public TestMethod() I|@+O#
{ ///xx/weblogic60b2_win.exe s3>a
try{ da$FY7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }3(!kW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aO'#!k*R
SiteFileFetch fileFetch = new SiteFileFetch(bean); $L/`nd
fileFetch.start(); s0SzO,Vi
} ]VI^ hhf
catch(Exception e){e.printStackTrace ();} jI-a+LnEm
^m>4<~/
98[uRywI
} Itl8#LpLM
Ca2r<|uA
<:S qMf
public static void main(String[] args) |L2>|4
{ -&Rv=q>
new TestMethod(); DH(<{ #u
} qmrT dG
} ].d2CJ'
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