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)); % ;6e@U}
} yiI&>J))
for(int i=0;i<nEndPos.length-1;i++) qvYw[D#.
{ gCwg ;c-
nEndPos = nStartPos[i+1]; Z,u:g c+*
} ld2\/9+n
nEndPos[nEndPos.length-1] = nFileLength; :&TOQ<vM
} k#&y
} >_&+gn${
L"('gc!W
gL}K84T$S
//启动子线程 roRZE[ya
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }A2@1TTPX
for(int i=0;i<nStartPos.length;i++) g7d)YUc
{ $>#PhOC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /- kMzL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X8*q[@$
nStartPos,nEndPos,i); y'E)iI*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fNB*o={r|
fileSplitterFetch.start(); k92189B9j/
} yl3iU:+V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t0?BU~f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -JUv'fk
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yY,.GzIjCj
nEndPos = " + nFileLength); YjG0: 9
// fileSplitterFetch[nPos.length-1].start(); [_H9l)
$9ON3>
B>~E6j7[Mp
//等待子线程结束 S!g&&RDx
//int count = 0; <y`yKXzBUV
//是否结束while循环 R8HA X
boolean breakWhile = false; *(r85lEou)
p]pFZ";70
<pPI:D@G
while(!bStop) P^1rNB
{ r*,]=M W
write_nPos(); :.sK:W("v
Utility.sleep(500); 1S_KX.
breakWhile = true; }b,a*4pN
nre8 F
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for(int i=0;i<nStartPos.length;i++) ][qZOIk@
{ &|9?B!,`
if(!fileSplitterFetch.bDownOver) h!)(R<
{ %7V?7BE
breakWhile = false; y0=BL
break; a2YdkdjT
} AY *
} G-} zkax
if(breakWhile) !)&-\!M>
break; y8,es$
kuUH2:L
][0HJG{{g
//count++; j[Et+V?
//if(count>4) )ns;S
// siteStop(); 8K1+ttjm
} \>jK\j
fxiq,o0
)fCl<KG*
System.err.println("文件下载结束！"); Kk??}
} JXvHsCd?
catch(Exception e){e.printStackTrace ();} &=s{ +0
} DpTQPu9
3HfT9
-98bX]8
//获得文件长度 ;N4mR6
public long getFileSize() wV(_=LF
{ dn5T7a~
int nFileLength = -1; /+66y=`UJ
try{ /=-E`%R}!
URL url = new URL(siteInfoBean.getSSiteURL()); 2U#OBvNU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @c.QrKSaD
httpConnection.setRequestProperty("User-Agent","NetFox"); Xv'64Nc!;
tc# rL
r4_ c~\jH
int responseCode=httpConnection.getResponseCode(); ,@>B#%Nz
if(responseCode>=400) !X#=Pt[,
{ y6G[-?"/Q
processErrorCode(responseCode); R4qS,2E
return -2; //-2 represent access is error =8<SKY&\X
} V:IoeQ]-
[;tbNVZK
{qh`8
String sHeader; LfK <%(:
3 #jPQ[+
"h)+fAT|,
for(int i=1;;i++) tb_}w@:kU
{ 6%:'2;xM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ou,B3kuQ+
//Utility.log(in.readLine()); &Cdd
sHeader=httpConnection.getHeaderFieldKey(i); x#pTB.
if(sHeader!=null) 1_<'S34
{ zzPgLE55
if(sHeader.equals("Content-Length")) ..n-&(c32
{ 9-L.?LG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h{>8W0W*
break; `cVG_=2
} |@Z QoH
} B\N,%vsx#U
else \7Zk[)!FL
break; WRD^S:`BH
} WXGLo;+>I
} `)SkA?yKI
catch(IOException e){e.printStackTrace ();} PRf2@0ZV
catch(Exception e){e.printStackTrace ();} \d v9:X$
Aja'`Mu
k.0$~juu
Utility.log(nFileLength); +fKLCzj
o>j3<#?
I,q3J1K
return nFileLength; Z/a]oR@
} *jDzh;H!w
i\,#Z!
<;_X=s`f,
//保存下载信息（文件指针位置） |ss_<
private void write_nPos() QvqX3FU
{ ;i Ud3'*
try{ T#h`BtET[
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6h;$^3x$
output.writeInt(nStartPos.length); UG1^G07s
for(int i=0;i<nStartPos.length;i++) ="Dmfy7
{ n {^D_S
// output.writeLong(nPos); ;2&(]1X
output.writeLong(fileSplitterFetch.nStartPos); o2Z# 5-
output.writeLong(fileSplitterFetch.nEndPos); E#ti
} X;zy1ZH
output.close(); }X}fX#[
} !9V_U
catch(IOException e){e.printStackTrace ();} M|76,2u
catch(Exception e){e.printStackTrace ();} j>P>MdZtk
} BcA:M\dK%
B;_M52-B
5a4;d+
//读取保存的下载信息（文件指针位置） et)A$'Q
private void read_nPos() E[e ''
{ 8Gs{Zfp!D
try{ N<O^%!buR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *Q5/d9B8TN
int nCount = input.readInt(); wYNh0QlBH
nStartPos = new long[nCount]; ].`i`.T
nEndPos = new long[nCount]; N"FQMxqm
for(int i=0;i<nStartPos.length;i++) Z?1.Y7Npr
{ -YRF^72+
nStartPos = input.readLong(); 8]+hfB/
nEndPos = input.readLong(); 8+ Hho@=
} 'rU5VrK
input.close(); h.G/HHz
} oXb}6YC
catch(IOException e){e.printStackTrace ();} [%YCupr#
catch(Exception e){e.printStackTrace ();} !a4pKN`qLY
} H?^Poe(=(
!=eui$]
;-U:t4
private void processErrorCode(int nErrorCode) X[|-F3o
{ eX$u
System.err.println("Error Code : " + nErrorCode); 42X[Huy]
} 2z&HT SI
QnVYZUgJeV
\vojF\
//停止文件下载 /R@eOl}D
public void siteStop() &o:wSe
{ 6uR:/PTG
bStop = true; bi[vs|
for(int i=0;i<nStartPos.length;i++) JZ80|-c
fileSplitterFetch.splitterStop(); ?v `0KF
[ 98)7
lYD-U8
} LB U]^t@ M
} dsrzXmE0
//负责部分文件的抓取 BTGPP@p4
**FileSplitterFetch.java If2f7{b
*/ _ jF, k>F
package NetFox; M>8#is(pV
#t po@pJsE
*|ubH?71%Y
import java.io.*; I}$Y[Jve
import java.net.*; B0nkHm.Sj
Ws.F=kS>h
dk-Y!RfNx
public class FileSplitterFetch extends Thread { 4GeWo@8h
;1K.SDj
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String sURL; //File URL )Q&:$]
long nStartPos; //File Snippet Start Position 0P&rTtU6
long nEndPos; //File Snippet End Position Z[Uz~W6M]
int nThreadID; //Thread's ID 0ir]
boolean bDownOver = false; //Downing is over ^JJ*pT:
boolean bStop = false; //Stop identical qAHQZKk
FileAccessI fileAccessI = null; //File Access interface >t3%-Kc
T"XZ[q
-7$7TD`'7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DMsxHAE1
{ 7_ZfV? .
this.sURL = sURL; b-yfBO
this.nStartPos = nStart; C.Y]PdYyj
this.nEndPos = nEnd; kk )9!7
nThreadID = id; F@)wi0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M7BJ$fA0E
} ^4h/6^b0c
b~WiE?
bK<'J=#1
public void run() Mb"i}Yt{
{ gW$X8ECX
while(nStartPos < nEndPos && !bStop) `o)rAD^e
{ %N=-i]+Id
oj;Rh!O
fiES6VL
try{ QI.{M$,m~
URL url = new URL(sURL); {D 9m//x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G;>b}\Ng
httpConnection.setRequestProperty("User-Agent","NetFox"); 9jCn|+
String sProperty = "bytes="+nStartPos+"-"; &r;-=ASYzV
httpConnection.setRequestProperty("RANGE",sProperty); TW7jp
Utility.log(sProperty); q`{crY30
oGu-:X=`9
2dFC{US'
InputStream input = httpConnection.getInputStream(); 48Vmz
//logResponseHead(httpConnection); .|G([O^H
vB hpD
QcU&G*
byte[] b = new byte[1024]; u|BD=4*
int nRead; !Z3iu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DwMq
{ /YKg.DA|
nStartPos += fileAccessI.write(b,0,nRead); [daUtKz
//if(nThreadID == 1) x4r\cL1!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [>U'P1@ql
} j;WZ[g#t
/2Y t\=S=
:&S6AP
Utility.log("Thread " + nThreadID + " is over!"); h;u8{t"
bDownOver = true; |$f.Qs~?
//nPos = fileAccessI.write (b,0,nRead); &"p7X>bd
} >ZTRwy`_(
catch(Exception e){e.printStackTrace ();} kn:X^mDXC/
} ?>92OuG%W?
} ^7G@CBic"
jgQn^
8' M43n
//打印回应的头信息 ]DHB'NOh,
public void logResponseHead(HttpURLConnection con) u!S^lV@
{ kc Q~}uFB
for(int i=1;;i++) |_xU{Pu
{ p%/Z
String header=con.getHeaderFieldKey(i); LZG?M|(6D
if(header!=null) _lcx?IV
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k)U9%Pr
Utility.log(header+" : "+con.getHeaderField(header)); V^sZXdDNL
else e`27 ?
break; P-[6'mw`
} Ha>Hb`
} Ka%u#};
gY9HEfB
&FHzd/
public void splitterStop() FZf{kWH
{ /@h)IuW
bStop = true; `@!4#3H
} I?<5 %
GTgG0Ifeh
8vpB(VxV+
} #e|G!'wdj
~\B1\ G
DyhW_PH2J
/* Tk\?$n
**FileAccess.java t@m!k+0
*//文件访问(定位，写) OMgFp|^
package NetFox; <Ih)h$8`
import java.io.*; r{R879
n]{sBI3
Q"rQVO
public class FileAccessI implements Serializable{ `>'%!E9G
WD.td
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4}-{sS}MP
RandomAccessFile oSavedFile; +||y/}1
long nPos; jRdmQmTJ
h]WPWa)M
.S4c<pMap
public FileAccessI() throws IOException Y=0D[o8
{ #2 Gy=GvV
this("",0); ~nLE?>x|Z
} %+gK5aVab
%QYW0lE
2E7vuFH4c
public FileAccessI(String sName,long nPos) throws IOException gkkT<hEV=
{ -|_#6-9
oSavedFile = new RandomAccessFile(sName,"rw"); "]H_;:{f
this.nPos = nPos; %? 87#|
oSavedFile.seek(nPos); `_"F7Czn
} .l1uqCuB
JO3"$s|t
N(ov.l;
public synchronized int write(byte[] b,int nStart,int nLen) [9N>*dKB
{ T'C^,,if
int n = -1; 'Z;8-1M?O
try{ :]]#X ~J
oSavedFile.write(b,nStart,nLen); jgpSFb<9F
n = nLen; 5 1&||.
} olLVT<
catch(IOException e) q%&JAX=
{ 'tyblj C
e.printStackTrace (); d-k`DJ!
} q)N]*~
~|CWy
dbVMG-z8
return n; |-+IF,j
} 9pF@#A9p
<?8aM7W7
z.d1>w
} `_;sT8
WZh%iuI{C
L<dJWxf?D
/* >G#SfE$0
**SiteInfoBean.java WlJ=X$
*/ r~2>_LK
package NetFox; 'aV/\a:*
o*5iHa(Qm
yq7gBkS
public class SiteInfoBean { ~(v7:?
c2E*A+V#u
B:X,vE
private String sSiteURL; //Site's URL =5l20 Um
private String sFilePath; //Saved File's Path _EEOBaZ
private String sFileName; //Saved File's Name IJ[r!&PY
private int nSplitter; //Count of Splited Downloading File |^:qJ;dOP
3:]c>GPQ
pHNo1-k\
public SiteInfoBean() UA0j#
{//nSplitter的缺省值为5 .Tm m
//default value of nSplitter is 5 t@"i/@8x$
this("","","",5); arWP]%E0W
} $:l>g)c
A.YXK%A%
E&z`BPd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Vf*Z}'
{ @yImR+^.7
sSiteURL= sURL; S&JsDPzSd
sFilePath = sPath; ! )x2
sFileName = sName; WgTD O3
this.nSplitter = nSpiltter; od=x?uBVd
dilom#2l
<@448,9&
} a]S0|\BkN
ovXU +8
*r90IS}A$2
public String getSSiteURL() d94Le/E
{ .D8|_B
return sSiteURL; Tf*DFyr
} .91@T.
1SK|4Am
ybY[2g2QJ
public void setSSiteURL(String value) _GbwyfA n#
{ 3bN]2\
sSiteURL = value; chC= $(5t
} _uf,7R-
Y W9+.Dc`
hj4mbL
public String getSFilePath() F$6JzF$|F
{ je#OV,uHM
return sFilePath; h<0&|s*a)
} }mdk+IEt
b0|;v-v
"h`oT4j5q
public void setSFilePath(String value) :3N&&]
{ Y n7z#bu
sFilePath = value; YZdV0-S
} $*')Sma
$o%:ST4
zB68%
public String getSFileName() )q|a Sd
{ VFI\2n`
return sFileName; ^:cc3wt'3[
} I<+i87=
EA``G8Vn>
+bDBc?HZ{$
public void setSFileName(String value) 8\VP)<<
{ rNN,!
sFileName = value; 3YO%$
} J\l'nqS"
[k<.BCE
e2_p7
public int getNSplitter() DD fw& y
{ ;.U<Lr^9#
return nSplitter; {A`J0ol<B9
} E (.~[-K4
"$krK7Z
)&{<gyS1
public void setNSplitter(int nCount) ,_M
{ HD_ #-M
nSplitter = nCount; : *8t,f~s^
} J?%ecCN
} w.o>G2u
3j7Na#<tL3
@#QaaR;4
/* `e[>S
**Utility.java 7R7e3p,K
*/ 6>NK2} `
package NetFox; ){I!orQ
"$#<+H>O
-T=sY/O
public class Utility { {2.zzev'
&V(;zy4(R
#ZyY(S1.
public Utility() 34F;mr"yp
{ j"r7M|Z+V
!nDiAjj
q|ZzGEj:OV
} J3QL%#
i4}+n^oSYo
//线程睡眠 2|A?9aE%0
public static void sleep(int nSecond) k?;@5r)y-
{ qYP;`L}o#
try{ J{U 171
Thread.sleep(nSecond); ]o?r(1
} f=hT o!i
catch(Exception e) Y(&rlL(sPK
{ eq(1'?7]`G
e.printStackTrace (); uGpLh0
} 8RA
} -2B3 xIZJ
QV[#^1
//日志 nrV!<nNBk
public static void log(String sMsg) "F:V$,mJ
{ Vji:,k=3\
System.err.println(sMsg); |)*9BN
} {,B.OM)J
Wud-(19
^{Fo,7
public static void log(int sMsg) }2hU7YWt
{ NjbIt=y
System.err.println(sMsg); \GPTGi5A
} l T#WM]
} )kEH}P&
{X10,
3Z}v%=5 "
/* Hxx]q+DAS
**TestMethod.java \SN>Yy
*/ \Mzr[dI
package NetFox; N4l}5(e
aTwBRm
muMd9\p
public class TestMethod { qVssw* GDB
88KQ) NU
Vg(FF"
public TestMethod() .hRtQU
{ ///xx/weblogic60b2_win.exe Dkg^B@5Xr
try{ M%Zh{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A|(!\J0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `=lo.c
SiteFileFetch fileFetch = new SiteFileFetch(bean); BtrMv6
fileFetch.start(); @E4ya$A)F
} Q`!^EyRA:^
catch(Exception e){e.printStackTrace ();} ~t1?oJ
DQ@M?~1hp
2f6BZ8H+Z
} BvS!P8
NJCSo(O
&2nICAN[
public static void main(String[] args) L[^.pO
{ D*/fY=gK
new TestMethod(); g:s|D hE[
} E/<n"'0ek
} [!#}#
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