http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); ><Z`)}f
} ;p}X]e l}
for(int i=0;i<nEndPos.length-1;i++) D/= AU
{ auP6\kpMe
nEndPos = nStartPos[i+1]; p .^#mN
} (0/)vZc
nEndPos[nEndPos.length-1] = nFileLength; drZ1D s
} V`MV_zA2
} 9e:}qO5)
}R -azN;
Q #%C)7)
//启动子线程 @hE$x-TP0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; HX]pcX^K
for(int i=0;i<nStartPos.length;i++) umD[4aP~;
{ A&~<qgBTp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FOU^Wcop%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :RnFRAcr
nStartPos,nEndPos,i); E"P5rT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]EzX$T
fileSplitterFetch.start(); ?/,sKF74i
} dU~DlaEy(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H' [#x2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +|w-1&-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z=vzF0
nEndPos = " + nFileLength); jBvZ>H+w~
// fileSplitterFetch[nPos.length-1].start(); *qLOr6
){.J`X5r
IiV#V
//等待子线程结束 (HUGgX"=
//int count = 0; ;-koMD!2F
//是否结束while循环 ;S FmbZ%~
boolean breakWhile = false; lilKYrUmG
fJ?$Z|
]eJjffx
while(!bStop) !:[kS1s>M
{ tilL7
write_nPos(); 79>8tOuo
Utility.sleep(500); +r+H`cT@
breakWhile = true; b7:B[7yK.x
ms%Ot:uA
o9:GKc
for(int i=0;i<nStartPos.length;i++) F+`DfI]/m
{ 3??*G8Yp
if(!fileSplitterFetch.bDownOver) om"q[Tudc
{ *Iu .>nw
breakWhile = false; ZhWtY
break; # Z*nc0C
} a?IL6$z
} K_Jo^BZ
if(breakWhile) Xj\SJ*
break; o'3t(dyyH
Xjal6e)[
3huTT"G
//count++; bm{L6D E
//if(count>4) |xTf:@hgHf
// siteStop(); ZcXqH7`r
} U~SOHfZ%(
=%:mZ@x'
}@pe`AF^
System.err.println("文件下载结束！"); _J51:pi
} HHbkR2H1
catch(Exception e){e.printStackTrace ();} ms8PFu(f
} r"a4;&mf
}31z 35
7^bO`
//获得文件长度 %NbhR(
public long getFileSize() 0;-S){
{ {.We%{4V
int nFileLength = -1; 1R/=as,R
try{ 7/;Xt&
URL url = new URL(siteInfoBean.getSSiteURL()); =W9;rQm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k!]Tg"]JAh
httpConnection.setRequestProperty("User-Agent","NetFox"); wR;_x x
]FLuiC
W"mkNqH
int responseCode=httpConnection.getResponseCode(); %$ ^yot
if(responseCode>=400) Te"<.0~1
{ _|MY/SN4A
processErrorCode(responseCode); j.GpJDq
return -2; //-2 represent access is error /tno`su;
} 4QnJ;&~
K5Fzmo a
'|e5cW6z
String sHeader; Dg_/Iu>OAE
^P-!pK*
3<x_[0v`K1
for(int i=1;;i++) p&F=<<C
{ PX](hc=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _4z>I/R>Z
//Utility.log(in.readLine()); G!uQ|<(
sHeader=httpConnection.getHeaderFieldKey(i); yZaQ{]"
if(sHeader!=null) x3L3K/qMg
{ $-VW)~Sl
if(sHeader.equals("Content-Length")) R Nr=M^Zn
{ l_LfVON
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AA}M"8~2
break; O{rgZ/4Au
} Rww"Z=F
} r+HJ_R,5A
else &X^~%\F:2
break; !+cRtCaA::
} ru)%0Cyx
} kTG}>I
catch(IOException e){e.printStackTrace ();} n<7#?X7
catch(Exception e){e.printStackTrace ();} M`umfw T
H7)(<6b,z
^HHJ.QR
Utility.log(nFileLength); =5_8f
7/(C1II.Q
u~?]/-.TY
return nFileLength; <;x+?j
} dL")E|\\k
~s{$&N
oZ%t!Fl1
//保存下载信息（文件指针位置） rQK2&37-,@
private void write_nPos() tiwhG%?2
{ Y(/VW&K&:
try{ n$}c+1
output = new DataOutputStream(new FileOutputStream(tmpFile)); a2iaP
output.writeInt(nStartPos.length); jHB,r^:'
for(int i=0;i<nStartPos.length;i++) bdqo2ZO
{ lN1T\
// output.writeLong(nPos); D?]aYCT
output.writeLong(fileSplitterFetch.nStartPos); hGF:D#jyT
output.writeLong(fileSplitterFetch.nEndPos); k+-u4W
} 6R@ v>}
output.close(); G\TyXq_4
} 8Md*9E#J("
catch(IOException e){e.printStackTrace ();} <"CG%RGP
catch(Exception e){e.printStackTrace ();} =Ze~6vS,
} %Q}#x
6ssZg@}nf{
(XT^<#Ga
//读取保存的下载信息（文件指针位置） VX&KGG.6
private void read_nPos() +YhTb
{ O" ['.b
try{ +S|y)W8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E](Ood
int nCount = input.readInt(); p=9G)VO
nStartPos = new long[nCount]; 1h]Dc(Oc#=
nEndPos = new long[nCount]; "xS",6Sy
for(int i=0;i<nStartPos.length;i++) wamqeb{u
{ " I`<s<
nStartPos = input.readLong(); `-Gs*#(/
nEndPos = input.readLong(); Tb}`]Y`X
} (q*T.
input.close(); )R{4"&&2
} s<z{(a
catch(IOException e){e.printStackTrace ();} 4jis\W}%L3
catch(Exception e){e.printStackTrace ();} 6}Y^X
} @<},-u
ksm=<I"C
EEn}Gw
private void processErrorCode(int nErrorCode) ~|Gtm[9Ru
{ !=cW+=1
System.err.println("Error Code : " + nErrorCode); jbC7U9t7
} CbS9fc&
|,t#Au}61
fVo)# Bj
//停止文件下载 }RDhI1x[mk
public void siteStop() 6P?
{ ]t7<$L
bStop = true; dB_\0?jJ-
for(int i=0;i<nStartPos.length;i++) ]O7I7K
fileSplitterFetch.splitterStop(); <8r%_ ']
2}I1z_dq~
C/_W>H_
} O,9KhX+
} b V;R}3)
//负责部分文件的抓取 O>|Q Zd
**FileSplitterFetch.java Q?7UiTZ
*/ n`0}g_\q
package NetFox; 3boINmX
+Medu?K `
|nz,srr~
import java.io.*; 398}a!XM
import java.net.*; gjL>FOe8u
lXW.G
WZ@nuK.39T
public class FileSplitterFetch extends Thread { #\@*C=
mWUQF"q8
cl1h;w9s
String sURL; //File URL M*8Ef^-U`t
long nStartPos; //File Snippet Start Position /S\P=lcb
long nEndPos; //File Snippet End Position 1/6G&RB
int nThreadID; //Thread's ID vy1:>N?#5
boolean bDownOver = false; //Downing is over JL`n12$m
boolean bStop = false; //Stop identical *8,]fBUq
FileAccessI fileAccessI = null; //File Access interface MBXumc_g
sh:sPzQ%Jv
ga6M8eOI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~e ]83?
{ m}Kn!21
this.sURL = sURL; 5RI"gf
this.nStartPos = nStart; <.s[x~b\`
this.nEndPos = nEnd; vDv:3qN7(
nThreadID = id; a0CmCv2#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ArbfA~jXB
} cZZ-K?_
FuLP{]Y+AM
9'\18_w
public void run() :)cPc7$8
{ Kt;h'?
while(nStartPos < nEndPos && !bStop) _CciU.1k&,
{ 536H*HdN
(Pbdwzao
\;.\g6zX
try{ +P6q wh\v
URL url = new URL(sURL); t]2~aK<]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tO)mKN+ (
httpConnection.setRequestProperty("User-Agent","NetFox"); 2^E.sf$f
String sProperty = "bytes="+nStartPos+"-"; e%U0^! 8
httpConnection.setRequestProperty("RANGE",sProperty); vtv|H
Utility.log(sProperty); 5yuj}/PZ
xWU0Ev)4U
D7olu29
InputStream input = httpConnection.getInputStream(); &^{HD }/{b
//logResponseHead(httpConnection); |t!kD(~r
Vqb4 MWW
L#M9!
byte[] b = new byte[1024]; r|{h7'
int nRead; (@pE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #K"jtAm
{ !WR(H&uBr\
nStartPos += fileAccessI.write(b,0,nRead); # ~} 26
//if(nThreadID == 1) bezT\F/\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uv/I`[@HK8
} F(Pe@ #)A
Ky8sLm@
imZi7o
Utility.log("Thread " + nThreadID + " is over!"); 3uZY.H+H
bDownOver = true; ^j0Mu.+_
//nPos = fileAccessI.write (b,0,nRead); V&eti2&zO
} UMma|9l(i
catch(Exception e){e.printStackTrace ();} Gvb>M=9
} wbyY?tH
} +5JCbT@y
l|/h4BJ'
B-@6m
//打印回应的头信息 Tu?+pz`h
public void logResponseHead(HttpURLConnection con) e_kP=|u)g
{ Nh^T,nv*l
for(int i=1;;i++) {W)Kz_
{ `M6!V
String header=con.getHeaderFieldKey(i); E*:!G
if(header!=null) 1j`-lD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M$B9?N6
Utility.log(header+" : "+con.getHeaderField(header)); _*>bf G
else +\fr3@Yc
break; =!*e; L
} j#f+0
} N/p9Ws
2%m H
0~iC#lHO
public void splitterStop() zcF~6-aQ
{ eB%KXPhMm
bStop = true; AE={P*g
} %g5TU 6WP
9TIyY`2!
h3Nwxj~E
} ms{:=L2$$
Kyt.[" p
1XSA3;ZEc
/* &=Gz[1 L
**FileAccess.java jrbEJ.
*//文件访问(定位，写) W2D^%;mw
package NetFox; GpMKOjVm|
import java.io.*; AON";&dLq-
g{.>nE^Sc5
"w9LQ=mW
public class FileAccessI implements Serializable{ ^VK-[Sz&
Nwr.mtvh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :3^b>(W.
RandomAccessFile oSavedFile; 11glFe
long nPos; %<lfe<;^t
(%}T\~`1z#
0#pjfc `:
public FileAccessI() throws IOException A[oLV"J6x5
{ W$B&asO
this("",0); *;"N kCf
} bY|%ois4
}__g\?Yf
R7;SZo
public FileAccessI(String sName,long nPos) throws IOException IfzHe8>
{ veFl0ILd
oSavedFile = new RandomAccessFile(sName,"rw"); Gtd!Y x
this.nPos = nPos; )xX(Et6+`
oSavedFile.seek(nPos); 9I0/KuZd O
} :y==O4
]sjYxe
^m;dEe&@F
public synchronized int write(byte[] b,int nStart,int nLen) dB+x,+%u+
{ ?VrZM
int n = -1; r5jiB L~
try{ >!s=f
oSavedFile.write(b,nStart,nLen); $/90('D
n = nLen; f#_XR
} +-&N<U
catch(IOException e) F's($n
{ ?Z0T9e<
e.printStackTrace (); /=w9bUj5v
} d"<Q}Ay
^.5L\
E1IRb':
return n; A ${b]
} kq6S`~J^R
@[#U_T- I
;>QED
} RqgH,AN
|:$D[=
y3F13 Z@%
/* 3v)v92;
**SiteInfoBean.java +(0Fab8g
*/ 9r-]@6;
package NetFox; TC[_Ip&
lTJ1]7)
o90SXa&l/
public class SiteInfoBean { Qj5~ lX`W
}ddwL
xoF]r$sC8
private String sSiteURL; //Site's URL -fw0bL%0
private String sFilePath; //Saved File's Path h>-JXuN
private String sFileName; //Saved File's Name DE|r~TQ
private int nSplitter; //Count of Splited Downloading File aDFu!PLB{)
3t22KY[`
%ANo^~8
public SiteInfoBean() .yE!,^j.gB
{//nSplitter的缺省值为5 AN7WMX
//default value of nSplitter is 5 OLJb8kO
this("","","",5); $C0NvJf
} /%C6e )7BL
_+g5;S5
"'h?O*V]u{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $gT+Ue|7
{ jXvGL
sSiteURL= sURL; p.^mOkpt
sFilePath = sPath; Z m9 e|J
sFileName = sName; :LBG6J
this.nSplitter = nSpiltter; lS]<~
$3S6{"
fI>>w)5
} ?#!Hm`\.
kKVd4B[#*
%[\: 8
public String getSSiteURL() n"vl%!B
{ a]'sby
return sSiteURL; wNL!T6"G
} z!;n\CV@
8*kZ.-T B
)QE7$|s
public void setSSiteURL(String value) *cxmQ
{ 9+"D8J7
sSiteURL = value; QW#]i
} r`XIn#o
\s?OvqI:
s^ rO I~
public String getSFilePath() y ,isK
{ `l@[8H%aw
return sFilePath; @%&;V(
} $r|R`n=
Yh_H$uW
fiz2544
public void setSFilePath(String value) PxzeN6f
{ (RG\U[
sFilePath = value; 95Bw;U3E
} 1}#v<b$
@?iLz7SPk
P7QOlTQI
public String getSFileName() n={}='
{ \kcJF'JFA0
return sFileName; z_R^n#A~r
} JL $6Fw;
fpf1^TZ
ozH7c_ <
public void setSFileName(String value) W)JUMW2|
{ 4O_z|K_k|
sFileName = value; r|4jR6%<'m
} BM=`zGh"
`?LQd2p
ta"/R@ k*
public int getNSplitter() ;tTM3W-h
{ 'c5#M,G~
return nSplitter; \eF5* {9
} 4"1OtBU3
6l&m+!i
&i"33.#]
public void setNSplitter(int nCount) jm&?;~>O
{ 16/+ O$#y
nSplitter = nCount; <_@ K4zV
} 6} "?eW
} 2A|^6#XN'
*6 -;iT8
6la# 0U23
/* ?xh_qy;
**Utility.java ,6Sa
*/ J XKps#,(#
package NetFox; _?>!Bz m
4NN-'Z>a
3lH#+@
public class Utility { 7vUfA"
c_clpMx=
,OWdp<z
public Utility() w,TyV%b[_
{ !+Z"7e nj
ANtp7ad
sj a;NL
} J7$1+|"
N[X%tf\L]F
//线程睡眠 rg+28tlDn
public static void sleep(int nSecond) nR4L4tdS
{ GjZ@fnF
try{ VaC#9Tp2X
Thread.sleep(nSecond); 1Lz`.%k`:
} o/buU{)y
catch(Exception e) 0CS^S1/[B`
{ nV38Mj2U
e.printStackTrace (); x&sT )=#
} :p@H
} MbLG8T:y
u_.V]Rjc
//日志 84L!r
public static void log(String sMsg) r5Ej
{ zk5sAHQ
System.err.println(sMsg); +*,rOK`C
} zf$&+E-
Hb'fEo r
Pc{D,/EpR
public static void log(int sMsg) lMAmico
{ !jY/}M~F1
System.err.println(sMsg); heoOOP(#
} SFoF]U09
} vM~/|)^0sW
i0/gyK
RtH[OZu(8
/* %(;jx
**TestMethod.java C&D]!ZvF
*/ W~p^AHco`
package NetFox; Tj*o[2mD
-cyJjLL*
=YF\mhMQ:
public class TestMethod { 5FqUFzVqsl
n>>hfxv(O!
Hf+A52lrf
public TestMethod() /:"%m:-P
{ ///xx/weblogic60b2_win.exe Djx9TBZ5
try{ Lv,~Mf1|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gJi11^PK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Wd$N[|
SiteFileFetch fileFetch = new SiteFileFetch(bean); Rg)\o(J
fileFetch.start(); 9 U1)sPH;
} 9bgKu6-X
catch(Exception e){e.printStackTrace ();} M_MiY|%V/K
$>'}6?C.
.6!]RA5!=
} Cih}
Oz^+;P1
]@l~z0^|[_
public static void main(String[] args) &k\7fvF
{ 6_;3
new TestMethod(); ERL(>)
} ;G!X?(%+
} @SPmb o
点击下载更多相关资料