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)); ZP4y35&%y
} 5pxw[c53#
for(int i=0;i<nEndPos.length-1;i++) U;U19[]
{ H<3ayp$
nEndPos = nStartPos[i+1]; M9(Kxux#
} HwBJUr91]
nEndPos[nEndPos.length-1] = nFileLength; U]iZ3^8VT
} )dRBI)P
} DV~g
04!akPP<
1F[W~@jW
//启动子线程 l`EKL2n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r 4+%9)
for(int i=0;i<nStartPos.length;i++) 'u%SI]*;>
{ YM +4:P2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .!g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,k6V?{ZA
nStartPos,nEndPos,i); )s8{|)-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]nx5E_j2
fileSplitterFetch.start(); #D8u#8Dz
} BHIC6i%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]Cc8[ZC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -Rr Qv(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T=T1?@2C
nEndPos = " + nFileLength); <ta#2
// fileSplitterFetch[nPos.length-1].start(); S>EO6z#
Jgzg[6
<Lfo5:.
//等待子线程结束 Qr*7bE(a
//int count = 0; Jnq}SUev
//是否结束while循环 W0N*c*k
boolean breakWhile = false; JO|xX<#:
T2MXwd&l
-f%J_`
while(!bStop) b:6e2|xf?
{ Ve|=<7%%S
write_nPos(); ~&Y%yN^
Utility.sleep(500); JcI~8;Z@Z~
breakWhile = true; Zl=IZ?F
'FmnlC1
6kHb*L Je
for(int i=0;i<nStartPos.length;i++) #s|/5[i
{ FDIOST !
if(!fileSplitterFetch.bDownOver) Gbc2\A\
{ 0D^c4[Y'l
breakWhile = false; 2g_2$)2
break; `EzC'e
} {~~'
} iea7*]vW
if(breakWhile) `:;fc
break; vI+X9C?
Mp`i@pm+
0z=^_Fb
//count++; '645Fr[lg
//if(count>4) LP5@ID2G
// siteStop(); rsC^Re:*jr
} mpDQhD[n
aA&}=lm
=F90SyzTy
System.err.println("文件下载结束！"); E|omC_h
} S"Mm_<A$@
catch(Exception e){e.printStackTrace ();} y@u,Mv
} y>_*}>2,O
Q%^!j_#
.V\:)\<|
//获得文件长度 Tq!.M1{&
public long getFileSize() s_Gf7uC
{ jL9to6 Hmr
int nFileLength = -1; |s*tRag
try{ ~YCZvJ
URL url = new URL(siteInfoBean.getSSiteURL()); w2o5+G=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ub=Bz1._
httpConnection.setRequestProperty("User-Agent","NetFox"); xC.Tipn>
"*0h=x$
zT"W(3
int responseCode=httpConnection.getResponseCode(); "gGv>]3
if(responseCode>=400) eUm,=s
{ WxI_wRKx
processErrorCode(responseCode); dI$M9;
return -2; //-2 represent access is error R}Z2rbt
} |;(0]
6`sS8Ar&u
?cD2EX%(
String sHeader; >p@v'h/Cr
\}+b_J6-
c:sk1I,d~^
for(int i=1;;i++) O2C&XeB:4
{ $jgEB+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )0p7d:%mV
//Utility.log(in.readLine()); FW--|X]8
sHeader=httpConnection.getHeaderFieldKey(i); qQx5n
if(sHeader!=null) :x/L.Bz
{ n6s[q-td
if(sHeader.equals("Content-Length")) k&SI-jxj
{ ^h\Y.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p}O[A`
break; kxVR#:
} +LeM[XX
} x4nmDEpa
else 7\sRf/
break; $mq@g
} w@"l0gm+u[
} JN:EcVuy
catch(IOException e){e.printStackTrace ();} e!JC5Al7
catch(Exception e){e.printStackTrace ();} c6Z\ecH9
m(?ZNtBQt
{|ChwM\x
Utility.log(nFileLength); OVgx2_F
4J6,_8`U
}E]&,[4&M
return nFileLength; j9]H~:g$d
} O[/l';i
BARs1^pR4
leomm+f^
//保存下载信息（文件指针位置） y(uE
private void write_nPos() ej&ZE n
{ La#otuw+?
try{ STY\c5
output = new DataOutputStream(new FileOutputStream(tmpFile)); :r,o-D
output.writeInt(nStartPos.length); `' "125T
for(int i=0;i<nStartPos.length;i++) l&LrcM
{ UpIt"+d2&
// output.writeLong(nPos); yCLDJ%8
output.writeLong(fileSplitterFetch.nStartPos); |#_`aT"
output.writeLong(fileSplitterFetch.nEndPos); Eggdj+
} wEJ) h1=)^
output.close(); /!L#cUog
} !Al?B9KJ
catch(IOException e){e.printStackTrace ();} 22gk1'~dO
catch(Exception e){e.printStackTrace ();} .S=^)
} qe"t0w|U?
7G<v<&
uy^vQ/
//读取保存的下载信息（文件指针位置） "ZU CYYre
private void read_nPos() /,m!SRJ
{ ui$JQ_P
try{ ?YTngIa
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H^N 5yOj/
int nCount = input.readInt(); DEcsFC/SK
nStartPos = new long[nCount]; a2tRmil
nEndPos = new long[nCount]; E |BE(F;K
for(int i=0;i<nStartPos.length;i++) NHjZ`=Js
{ C/L+gU&
nStartPos = input.readLong(); 7xr@$-U
nEndPos = input.readLong(); ;Q&|-`NK
} ;)nV
input.close(); ~xSAR;8
} ollk {N
catch(IOException e){e.printStackTrace ();} sq~9 l|F
catch(Exception e){e.printStackTrace ();} A:-r2;xB
} quEP"
G^Q8B^Lg
C_~hX G
private void processErrorCode(int nErrorCode) X|iWnz+^
{ V<%eWT)x7C
System.err.println("Error Code : " + nErrorCode); 9;*-y$@
} &>]c"?C*
;5(ptXX1W
8vL2<VT;
//停止文件下载 2y0J~P!I
public void siteStop() SlRQi:
{ cB ,l=/?
bStop = true; vm y?8E6+
for(int i=0;i<nStartPos.length;i++) bb]r
fileSplitterFetch.splitterStop(); 6bXR?0$*M.
ToVi;
WzwH;!
} 2a3RRP
} WFTXSHcG
//负责部分文件的抓取 yaD_c;
**FileSplitterFetch.java X/l{E4Ex
*/ 3r]:k)J
package NetFox; ~Os1ir.
SL O~
I}S~,4
import java.io.*; {hmC=j
import java.net.*; [_pw|BGp
MY]<^/Q
6?C|pO
public class FileSplitterFetch extends Thread { ?mCino
n8dJ6"L<"
>ARZ=x[
String sURL; //File URL I\DH
long nStartPos; //File Snippet Start Position XFiP8aX<
long nEndPos; //File Snippet End Position &=-ZNWNo
int nThreadID; //Thread's ID qlJzXq{|`
boolean bDownOver = false; //Downing is over (WISf}[l;
boolean bStop = false; //Stop identical z9B""ws
FileAccessI fileAccessI = null; //File Access interface bkvm-$/
..5rW0lr
(&)PlIi7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8wXnc%
{ WX9ABh&5
this.sURL = sURL; -xXz}2S4
this.nStartPos = nStart; :47bf<w|Y
this.nEndPos = nEnd; &# ?2zbZ
nThreadID = id; Z@G[\"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 TJY [s-
} 2`?58&
ip`oL_c
jrl'?`O
public void run() EL?6x
{ qZS]eQW.
while(nStartPos < nEndPos && !bStop) @3Lh/&
{ Duu)8ru
&P@dx=6d
Q,f~7IVX
try{ >$RQ
URL url = new URL(sURL); Pd"=&Az|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z3bRV{{YqN
httpConnection.setRequestProperty("User-Agent","NetFox"); nN]GO}
String sProperty = "bytes="+nStartPos+"-"; 1j!LK-
httpConnection.setRequestProperty("RANGE",sProperty); w I7iE4\vz
Utility.log(sProperty); 1_of;=9V
;tZ;C(;<
k"z ~>
InputStream input = httpConnection.getInputStream(); s)L\D$;+O
//logResponseHead(httpConnection); t{ R\\j
<U]!1
qq,#bRe
byte[] b = new byte[1024]; 5!b+^UR;z
int nRead; $Sx(vq6(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /~O>He
{ j^Vr!y
nStartPos += fileAccessI.write(b,0,nRead); @X?7a]+;8
//if(nThreadID == 1) OABMIgX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?DwI>< W
} 4Ucs9w3[
aJ{-m@/5
e}u68|\EC
Utility.log("Thread " + nThreadID + " is over!"); 1LK`
bDownOver = true; EDA%qNd]j
//nPos = fileAccessI.write (b,0,nRead); S#{jyU9 ]
} b5@sG^
catch(Exception e){e.printStackTrace ();} sYG:\>}ie
} vR)f'+_Nz
} s<XAH7?0
o _G,Ph!7
ieL7jN,'m
//打印回应的头信息 n?[JPG2X
public void logResponseHead(HttpURLConnection con) i0TbsoKh:
{ (\8~W*ej"
for(int i=1;;i++) RXD*;B$v
{ X>la!}sV
String header=con.getHeaderFieldKey(i); UD!-.I]
if(header!=null) t4P`#,:8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nZbINhls
Utility.log(header+" : "+con.getHeaderField(header)); W0 n?S "
else "PD^]m
break; kF@Z4MB}yr
} IW{}l=D/
} d$H
hb.^&
@,:6wKMc
public void splitterStop() \`:nmFO(9
{ AbExJ~JV\g
bStop = true; sy]hMGH:3W
} x_+-TC4IXn
k',#T932x1
%4QpDt
} li37*
[pRRBMho
1`Ig A0V`"
/* iCtDV5
**FileAccess.java Nt w?~%
*//文件访问(定位，写) V"Sa9P{y"
package NetFox; !0Mx Bem
import java.io.*; -\9K'8 C
+e87/\5
PU2^4h/[`
public class FileAccessI implements Serializable{ o}p^q:T*
+Zg@X.z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cFZcBiw
RandomAccessFile oSavedFile; *8I"7'xh
long nPos; 'nT#c[x[0
WqJrDj~
jl"su:y
public FileAccessI() throws IOException ! }>CEE
{ =G9I7Y@
this("",0); rk-GQ#SKU
} fpa~~E-
:OFs"bC
PWBcK_4i%
public FileAccessI(String sName,long nPos) throws IOException KDS}"/
{ 7C9_;81_Dt
oSavedFile = new RandomAccessFile(sName,"rw"); -hY@r 7y
this.nPos = nPos; |kGQ~:k+P
oSavedFile.seek(nPos); +WjX@rSq[
} ~+)>D7
ZYS]Et[Q
|JLXgwML
public synchronized int write(byte[] b,int nStart,int nLen) oMNSQMlI
{ T'> MXFLh
int n = -1; &\y`9QpVF
try{ AGGT] 58|
oSavedFile.write(b,nStart,nLen); ^~;"$=Wf
n = nLen; 7|PB6h3
} Ii&\LJ
catch(IOException e) RG.wu6Av
{ v{X<6^g
e.printStackTrace (); !$hi:3{U,
} I<rT\':9
)~0TGy|
4Ql9VM%y
return n; #:NY9.\o
} ni85Ne$
IG Ax+3V
}a%1$>sj
} GO)5R,
$Jo4n>/
ph$vP;}
/* bO` SBq$
**SiteInfoBean.java @h9QfJ_f
*/ DF>3)oTF
package NetFox; SLW|)Q24
{2)).g
h343$,))u
public class SiteInfoBean { 2FcNzAaV
brX[-
5ZX
private String sSiteURL; //Site's URL v5\5:b{/
private String sFilePath; //Saved File's Path V}Ee1C
private String sFileName; //Saved File's Name :,ucJ|
private int nSplitter; //Count of Splited Downloading File #g/m^8n?s
U=WS]
x5|^p=
public SiteInfoBean() j5[Y0)pV\
{//nSplitter的缺省值为5 $XI.`L *g
//default value of nSplitter is 5 M-Ek(K3SRf
this("","","",5); %Gl1Qi+Po_
} PIAE6,*
ed2r<H$
!QpOrg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S Rk%BJ? ~
{ Ci4;e
sSiteURL= sURL; U&ytZ7iB
sFilePath = sPath; #jh5%@
sFileName = sName; THlQifA!
this.nSplitter = nSpiltter; l8khu)\n4R
la}cGZ; p.
f^ja2.*%?
} a^8PB|G
L~%7=]m
%!r.)Wx|2
public String getSSiteURL() pC]XbokES
{ Re2&qxE
return sSiteURL; snWe&-
} tpblm|sW
_, E/HAX
qW`?,N)r
public void setSSiteURL(String value) fwvwmZW
{ !1=*"H%t
sSiteURL = value; v;`>pCal
} U.5R3z
=Oq*9=v|
v[2&0&!K#
public String getSFilePath() qX*xQA|ak,
{ wTD}c1J(
return sFilePath; RRXp9{x`
} 51u\am'T
@dUN3,}
rvlvk"
public void setSFilePath(String value) 9;'#,b*(
{ IJ~j(.W
sFilePath = value; |RXQ_|
} _!E&%=f
)o<^6Ic%7
KIcIYCBz
public String getSFileName() Z+u.LXc|c
{ 51`&%V{daL
return sFileName; }h=PW'M{
} M\/hK2J# #
L$i:~6
*:Rs\QH
public void setSFileName(String value) [}M!ez
{ q-+:1E
sFileName = value; Rpv[rvK'
} 0-[naGz
4=ovm[
,zdGY]$
public int getNSplitter() i!RfUod
{ lm 96:S
return nSplitter; =@0J:"c
} YVwpqOE.=
Xl<iR]lda
|iI dm
public void setNSplitter(int nCount) 3C<G8*4);/
{ <zL_6Y2
nSplitter = nCount; 3LT~-SvL
} w|6/i/X
} q" f65d4c
lcm3wJ'w
/OWwC%tM/
/* xnt)1Q
**Utility.java ;Y[D#Ja-
*/ ^~.AV]t|
package NetFox; lOp.cU
[{Jo(X
:-5[0Mx=
public class Utility { F3EAjO)ch
Uns%6o
:09NZ !!
public Utility() jLVG=rOn
{ Ny^f'tsA
}%8ZN :
0cE9O9kE
} 0U@#&pUc
}L)[>
//线程睡眠 GTM0Qvf?
public static void sleep(int nSecond) u\Ylo.)b
{ $TmEVC^0
try{ g{Al:}u>
Thread.sleep(nSecond); (^35cj{s
} AU3Rz&~
catch(Exception e) [B#XA}w
{ 9zb1t1[W
e.printStackTrace (); $Yt|XT+!&
} 0M"n
} W`_JERo
1,%`vlYv
//日志 F5qA!jZ1]
public static void log(String sMsg) Q{|%kU"
{ P,ueLG=
System.err.println(sMsg); 953qz]Q8
} vII{i
s`_EkFw>Gl
h/t;ZLUAZP
public static void log(int sMsg) (<r)xkn
{ tg@61V?>
System.err.println(sMsg); >jsY'Bm
} U?sHh2*
} Tj#S')s8
< j:\;mi;
12z!{k7N
/* oj - `G
**TestMethod.java [j-?)
*/ /iFn=pk1?
package NetFox; Vml 6\X
wn5OgXxG<
"D _r</b
public class TestMethod { x[)-h/&Fh
RJ'[m~yl5X
} +}nrJv
public TestMethod() hm1s~@oEm
{ ///xx/weblogic60b2_win.exe Jg;[k
try{ a]u.Uqyx2w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q38+`EhLA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <E4(KE
SiteFileFetch fileFetch = new SiteFileFetch(bean); Tse#{
fileFetch.start(); GIM/T4!)
} q$:7j5E
catch(Exception e){e.printStackTrace ();} a#=d{/ab
C P}fxDW
A7Ql%$v7^
} 94+^K=lAX
}ouGxs+^[
{&n- @$?
public static void main(String[] args) zsXgpnlHT
{ Pp-N2t86#2
new TestMethod(); *~)6 sm
} Gk*u^J(
} IQPu%n{0v
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