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)); f4&k48Ds
} },vVc/
for(int i=0;i<nEndPos.length-1;i++) P*9L3R*=N
{ nIv/B/>pZ
nEndPos = nStartPos[i+1]; F/0x`l
} #5mnSky+s
nEndPos[nEndPos.length-1] = nFileLength; *","u;&
} Mx=L lC)
} ,=y8[(h
UjH+BC+9`b
<R8!fc{`
//启动子线程 lBfG#\rdW~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; J]qx4c
for(int i=0;i<nStartPos.length;i++) hdurT
{ ~A-VgBbU>_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~+Ows
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x).`nZ1
nStartPos,nEndPos,i); bb"x^DtT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,[)f-FmcU
fileSplitterFetch.start(); uqK[p^{
} [C(>e0r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xZp`Ke!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Rb_+C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c4xXsUBQk
nEndPos = " + nFileLength); A.(xa+z?
// fileSplitterFetch[nPos.length-1].start(); h/\/dp/tt
>y^zagC*
If%**o
//等待子线程结束 1}b1RKKj<
//int count = 0; ]|)M /U *
//是否结束while循环 _dynqF8*
boolean breakWhile = false; VU(#5X%Pn
hwdZP=X
LOlj8T8Z
while(!bStop) >;OwBzB
{ pQOT\- bD
write_nPos(); (S k+nD
Utility.sleep(500); _-bEnF+/0
breakWhile = true; \%/zf
6'QlC+E
1JO@G3,
for(int i=0;i<nStartPos.length;i++) 4-{f$Z@
{ \_PD@A9
if(!fileSplitterFetch.bDownOver) 6yPh0n
{ WU<C7
breakWhile = false; b5d;_-~d
break; r[y3@SE5
} oM)4""|
} -MT.qhx
if(breakWhile) 3hbUus
break; ]^?V8*zL]
b1frAA
^+q4*X6VB
//count++; 8WL*Pr1I
//if(count>4) o9L$B
// siteStop(); 5sK1rDN
} :} 9Lb)Yp
DJ<F8-sb2r
0FEn&\2<
System.err.println("文件下载结束！"); hNGD`"U
} ;mLbgiqQ J
catch(Exception e){e.printStackTrace ();} =9'px3:'WR
} `]\:%+-
T1c.ER}17
jq"iLgEMO
//获得文件长度 |_`wC
public long getFileSize() 5W~-|8m
{ aO>Nev
int nFileLength = -1; >KMTxHE`+
try{ 0I \l_St@
URL url = new URL(siteInfoBean.getSSiteURL()); TNK~ETE4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o? {rPFR
httpConnection.setRequestProperty("User-Agent","NetFox"); 0xe*\CAo
kmfxk/F}
u&s>UkR
int responseCode=httpConnection.getResponseCode(); GK-__Y.
if(responseCode>=400) b_xGCBC
{ k>dzeH
processErrorCode(responseCode); )A H)*Mg
return -2; //-2 represent access is error C'Z6l^{>
} 9q|36CAO_
E]IPag8C
;L.RfP"5<
String sHeader; !w-`:d?
YR} P;
(jB_uMuS
for(int i=1;;i++) -Rz%<`
{ biw2f~V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [n{c,U F
//Utility.log(in.readLine()); *^b<CZd9
sHeader=httpConnection.getHeaderFieldKey(i); ;fnE"}
if(sHeader!=null) "=ogO/_Q"
{ 8{iFxTz
if(sHeader.equals("Content-Length")) { WW!P,w
{ N J_#;t#j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tyyfMA?'L;
break; ww(.
} 5u3SP?.&
} ]6 ]Nr
else &H<n76G
break; M<"H1>q@
} e[AwR?=
} xfJ&11fG2
catch(IOException e){e.printStackTrace ();} Z>+Tzvfud
catch(Exception e){e.printStackTrace ();} ra*(.<&
TScI_8c>
C=|X]"*:u0
Utility.log(nFileLength); /WX 0}mWu
6}9`z8
Ko|p&-Z;
return nFileLength; _pS!sY~d
} 7y2-8eL
fPLi8`r
QN$Ac.F
//保存下载信息（文件指针位置） xIh,UW#
private void write_nPos() x%\m/_5w%
{ Kgw_c:/'
try{ s$ v<p(yl
output = new DataOutputStream(new FileOutputStream(tmpFile)); "P_PqM
output.writeInt(nStartPos.length); G)'(%rl
for(int i=0;i<nStartPos.length;i++) ;$= GrR
{ 2%F!aeX
// output.writeLong(nPos); N)H _4L
output.writeLong(fileSplitterFetch.nStartPos); ek3,ss3
output.writeLong(fileSplitterFetch.nEndPos); HD&Ag
} 4`mF6%UC
output.close(); -w#Hy>E
} ?c!W*`yP
catch(IOException e){e.printStackTrace ();} auKGm:
catch(Exception e){e.printStackTrace ();} +zup+=0e
} '7Aj0U(
ID1/N)56
iig ({b
//读取保存的下载信息（文件指针位置） 0`L>t
private void read_nPos() ?6[X=GeUs
{ c3NUJ~>=y
try{ sF=8E8qa
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D+:}D*_&
int nCount = input.readInt(); etHkyF
nStartPos = new long[nCount]; JIobs*e0m
nEndPos = new long[nCount]; x\m?*5p
for(int i=0;i<nStartPos.length;i++) HECZZnM
{ r{~@hd'Aj
nStartPos = input.readLong(); y$n`+%_
nEndPos = input.readLong(); O%n=n3
} DKGZm<G>
input.close(); 9:l@8^_o
} ^%:syg_RM[
catch(IOException e){e.printStackTrace ();} ==z,vxr
catch(Exception e){e.printStackTrace ();} 6+;B2;*3
} c8 xZT
d].(x)|st
pd1V8PZSG
private void processErrorCode(int nErrorCode) #g6*s+Gm
{ KW~fW r8
System.err.println("Error Code : " + nErrorCode); vKvT7Zxc
} /EpsJb`kj
2]f"(X4jp
(.DX</f/4
//停止文件下载 H!+T2<F9R
public void siteStop() x$'0}vnT
{ tbP ;iK'
bStop = true; [qEd`8V(
for(int i=0;i<nStartPos.length;i++) ~!Q\\_
fileSplitterFetch.splitterStop(); lN-[2vT<
!]-ET7
Vu`O%[Q/
} BVt)~HZ
} c!{]Z_d\
//负责部分文件的抓取 QE8aYPSFf
**FileSplitterFetch.java IO4 8sV }
*/ < x==T4n/
package NetFox; 34$qV{Y%y
@9wug!,
;1&7v
import java.io.*; bz=B&YR
import java.net.*; 8+irul{H_
5ma*&Q8+
A]FjV~PB
public class FileSplitterFetch extends Thread { #q5 L4uM9
3~%wA(|A
?l3PDorR
String sURL; //File URL sBo|e]m#
long nStartPos; //File Snippet Start Position w53+k\.
long nEndPos; //File Snippet End Position '*PJ-=G
int nThreadID; //Thread's ID r^$4]@Wn
boolean bDownOver = false; //Downing is over dIUg e`O9
boolean bStop = false; //Stop identical k7\h- yn{
FileAccessI fileAccessI = null; //File Access interface :&/b}b!)AX
* @QC:1k
/4R|QD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException '{t&!M`
{ 'z=QV{ni
this.sURL = sURL; hu G]kv3F:
this.nStartPos = nStart; ;U^7]JO;
this.nEndPos = nEnd; 5ecAev^1-
nThreadID = id; TZ]D6.mD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O'G,
} ft"B,
yE\dv)(<
z}" Xt=G?
public void run() uH6QK\
{ oA _,jsD4
while(nStartPos < nEndPos && !bStop) }h6N.vz
{ {bSi3oI
B[]v[q<
KV!!D{VS`@
try{ whzV7RT
URL url = new URL(sURL); Z|z+[V}[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `qjiC>9
httpConnection.setRequestProperty("User-Agent","NetFox"); A7;|~??
String sProperty = "bytes="+nStartPos+"-"; FTihxC?.L
httpConnection.setRequestProperty("RANGE",sProperty); jM E==)Y
Utility.log(sProperty); 1i.t^PY
<R6$ kom`
Rw54`_kFEB
InputStream input = httpConnection.getInputStream(); <oE(I)r4,
//logResponseHead(httpConnection); UY_'F5X
!1:364
{hr+ENgV
byte[] b = new byte[1024]; Wa8?o~0"L
int nRead; 0;b%@_E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J(\]39y
{ m|RA@sY%`
nStartPos += fileAccessI.write(b,0,nRead); p.gaw16}>
//if(nThreadID == 1) \s.c.c*eh;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y+k)d^6r
} /uc*V6Xd (
?E@9Nvr
)_bR"!Z
Utility.log("Thread " + nThreadID + " is over!"); O~r.sJ}
bDownOver = true; +~6gP!
//nPos = fileAccessI.write (b,0,nRead); Wm5/>Cu,
} gCMwmanX
catch(Exception e){e.printStackTrace ();} @q?zh'@;
} O>=D1no*
} %CxrXU
S}=euY'i
.H,wdzg)
//打印回应的头信息 `XwFH#_
public void logResponseHead(HttpURLConnection con) KT)A{i
{ (Ut)APM
for(int i=1;;i++) FQbF)K~e
{ +$eEZ;4
String header=con.getHeaderFieldKey(i); Yxal%
if(header!=null) xp395ub6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .@Z-<P"
Utility.log(header+" : "+con.getHeaderField(header)); fE\;Cbi
else UqaLTdYG
break; %n3lm(-0U
} m17H#!`
} {%S>!RA
"g)@jqq:>
p&nIUx"
public void splitterStop() g,5r)FU`
{ qL6Rs
bStop = true; u0;FQr2
} xZ*.@Pkr
7R 40t3
( aGwe@AS
} 1!@KRV
Zd/ACZ[
cG|ihG5)
/* 8+Y+\XZG
**FileAccess.java .[v4'ww^
*//文件访问(定位，写) ,8KD-"l^g
package NetFox; 0L "+,
import java.io.*; PKoB~wLH
zCdQI
~aK@M4
public class FileAccessI implements Serializable{ Wx;`=9
/7$3RV(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s V70a3#
RandomAccessFile oSavedFile; !5rja-h
long nPos; SBnwlM"AN
0ciPH:V
Yg5m=Lis
public FileAccessI() throws IOException wG1A]OJl1
{ kI>Iq Q-h
this("",0); Fd:A^]
} -saisH6
sv<U$M~)X
yq{k:)
public FileAccessI(String sName,long nPos) throws IOException QGtKu:c.81
{ 'CqWF"
oSavedFile = new RandomAccessFile(sName,"rw"); \vBpH'hR,'
this.nPos = nPos; #tyHjk
oSavedFile.seek(nPos); S!0ocS!t
} 5*=a*nD11
[vuqH:Ln
.JNU3%s
public synchronized int write(byte[] b,int nStart,int nLen) fmDU
{ fqaysy
int n = -1; 5>J{JW|
try{ A^PCI*SN[
oSavedFile.write(b,nStart,nLen); CD\k.
n = nLen; ]XX8l:+
} BJgg-z{Y
catch(IOException e) IS;F9{
{ [KIK}:
e.printStackTrace (); _yQ*
} Pdc- 3
p?OwcMT]M
WN?1J4H
return n; Y[=Gv6Fr
} S/j~1q_|G
8U8l 5r
uf;^yQi
} $9v:(:!Bm
y6|&bJ @
T<*i($ [
/* ~Uw**PT3M
**SiteInfoBean.java 6,j6,Q(67
*/ JO:40V?op
package NetFox; k^3|A3A
`3!ERQU
38IVSK_
public class SiteInfoBean { #t /.fd
{K-]nh/
9Ny{2m=Ye
private String sSiteURL; //Site's URL \~4uEk"]
private String sFilePath; //Saved File's Path V#;6<H"
private String sFileName; //Saved File's Name H R$\jJ
private int nSplitter; //Count of Splited Downloading File &P>wIbE
k> I;mEV
Cj?X+#J/@d
public SiteInfoBean() HH[b1z2D
{//nSplitter的缺省值为5 (`}O!;/E}
//default value of nSplitter is 5 .@#i
this("","","",5); " &B/v"nj
} ,fQc0gM=[
lc/q0
g2b%.X4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0r=:l/Pz
{ Y|FJ1x$r
sSiteURL= sURL; l^x5m]Kt
sFilePath = sPath; DXj_\ R(}
sFileName = sName; /[YH W]
this.nSplitter = nSpiltter; MF/359r)Et
Ob+L|FbnN
EB'(%dH
} 24_F`" :-=
g_Wf3o857J
8M m,a
public String getSSiteURL() S/CT;M@W
{ "WOY`su>
return sSiteURL; Pb$ep|`u
} ai% fj*
7MreBs(M
vKppXm1
public void setSSiteURL(String value) 1_uq46
{ hPt(7E2ke~
sSiteURL = value; ]qCAog
} +D|y))fE
uGl+"/uDu
yu~~"Rq)
public String getSFilePath() rt] @Z`w
{ [nBlHI;&
return sFilePath; mT\!LpX
} GuMsw*{>
k WYjqv
~JY<DW7
public void setSFilePath(String value) zm rQ7(y
{ IH?.s k
sFilePath = value; F,^Q'$!
} HaI
ou6|;*>d
IbAGnl{
public String getSFileName() $-9m8}U(Y
{ R?g qPi-
return sFileName; UPgjf
} Riid,n
RrSo`q-h+
C,:3z
public void setSFileName(String value) Oa=0d;_
{ o|G.tBpKg
sFileName = value; @qH{;
} ?g2Wu0<
Gc}d#oo*k
aloP@U/\Sn
public int getNSplitter() D^P_3 B+
{ w~sr2;rp<
return nSplitter; PNgj 8J4
} ZiodJ"r
DPIiGRw
>_h*N H
public void setNSplitter(int nCount) vsg"!y@v
{ v0`E lkaN
nSplitter = nCount; p;Kw$fQ?
} *b9=&:pU(
} R+IT)2
gTZ1LJ
'~A~gK0
/* n?vrsqmZ
**Utility.java ~0r:Wcj x
*/ bY7d
package NetFox; K:/%7A_{
5=/H2T!F
i[A$K~f
public class Utility { ,o\vumx
Yd:8iJA
fLl~a[(5
public Utility() ai[st+1
{ "#^11o8
4Y8/>uL
A?'Tigi
} 9r!psRA:`)
<<K GS
//线程睡眠 EXUjdJs"
public static void sleep(int nSecond) mu0ER 3o
{ ;_)&#X,?(
try{ jI!}}K)d
Thread.sleep(nSecond); wN8-Me
} Hj"`z6@7
catch(Exception e) _c?&G`
{ g|8G!7O
e.printStackTrace (); jV`xRjh
} HYf&0LT<11
} 0t?:
ax&,
//日志 $5T3JOFz
public static void log(String sMsg) _!kL7qJ"
{ %{g<{\@4(;
System.err.println(sMsg); n#,|C`2r
} 1foy.3g-
.<j\"X(
C]K|;VQ
public static void log(int sMsg) lO>w|=<
{ -kT *gIJ}
System.err.println(sMsg); j-@3jFu
} }N!I|<"/
} ju`x
x;2tmof=L
u{maE ,
/* 4~=/CaG~
**TestMethod.java Q)S0z2
*/ $+qJ#0OE$
package NetFox; 0q(}nv
EOWLGleD1
pme5frM|
public class TestMethod { 'v iF8?_
k\X1`D}R
sui3(wb
public TestMethod() q"4{GCavN
{ ///xx/weblogic60b2_win.exe <5 G+(vP
try{ #-kG\}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SbI %|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rAq2
SiteFileFetch fileFetch = new SiteFileFetch(bean); p5&:>>
fileFetch.start(); +m kub}<a
} (mIw3d8Tz
catch(Exception e){e.printStackTrace ();} AdDlS~\?
'H-: >'k
nn!W-Bsqjh
} &OD)e@Tc
E!w%oTx{OR
H@o3u>}
public static void main(String[] args) Ha{#
{ ^%tmHDNL.
new TestMethod(); G$&SlJZEk
} +@>K]hdr
} 9T#d.c24
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