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)); 4+ yd/^S
} #UI@<0P)
for(int i=0;i<nEndPos.length-1;i++) 0^:O:X
{ &ATjDbW*(
nEndPos = nStartPos[i+1]; }g>&l.2X
} ]>*Z 1g;
nEndPos[nEndPos.length-1] = nFileLength; =GFlaGD
} |w:7).P
} ]U'KYrh
DQKhR sC
"sL#)<%
//启动子线程 J&{E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ur]5AJ
for(int i=0;i<nStartPos.length;i++) 9K FWa0G
{ L!-T`R8'c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \CU.'|X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -DU[dU*~
nStartPos,nEndPos,i); 'OkF.bs
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CW, Kw
fileSplitterFetch.start(); l(%bdy
} OC"W=[Myl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J"I{0>@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^om(6JL2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s.Yywy
nEndPos = " + nFileLength); .i@e6JE~;
// fileSplitterFetch[nPos.length-1].start(); ECU:3KH>MF
? 0nbvV5v7
(Cqhk:F
//等待子线程结束 )[G5qTO
//int count = 0; H.!M_aJH
//是否结束while循环 Sf lHSMFw
boolean breakWhile = false; b_cD >A
<:>a51HBX
:2K0/@<x
while(!bStop) Z`q?pE>R
{ @/B&R^aVZ
write_nPos(); b.;F)(
Utility.sleep(500); &YqgMC
breakWhile = true; %3'80u6BCJ
e"[o2=v;5
V mKMj'
for(int i=0;i<nStartPos.length;i++) Hco[p+
{ M(I 2M
if(!fileSplitterFetch.bDownOver) g2w0#-
{ b@z/6y!
breakWhile = false; hPD2/M
break; dhsQfWg#}
} }3=]1jH6
} NC@OmSR\0
if(breakWhile) z.P) :Er
break; VmV/~-<Z
|c dQJW
m~#98ZJ^
//count++; NR^z!+oSR
//if(count>4) T+N%KRl
// siteStop(); Z?CmD;W
} w*\)]bTs
>%'|@75K
/nGsl<
System.err.println("文件下载结束！"); hJ+>Xm@@!
} 9q;+ Al^Z
catch(Exception e){e.printStackTrace ();} rFdq \BSi
} wUW+S5"K
\ec,=7S<Zf
7 45Uo'
//获得文件长度 JX`+b
public long getFileSize() DY0G;L3
{ zF3fpEKe
int nFileLength = -1; |jO&qT]{
try{ OUS@)Tyh
URL url = new URL(siteInfoBean.getSSiteURL()); zD7\Gv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kImS'i{A
httpConnection.setRequestProperty("User-Agent","NetFox"); '-S^z"ZrI
u ;f~
V!a\:%#^Y
int responseCode=httpConnection.getResponseCode(); )TBBYCL3
if(responseCode>=400) O: :X$O7
{ e>z3\4
processErrorCode(responseCode); d%u|) =7
return -2; //-2 represent access is error \h,S1KmIBD
} 8u!!a^F
j<Lj1P3
>z.o?F
String sHeader; rpQB# Pz
,eF}`
aOA;"jR1
for(int i=1;;i++) d^!)',`
{ 89k9#i X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [8(e`6xePb
//Utility.log(in.readLine()); ~4`LOROC
sHeader=httpConnection.getHeaderFieldKey(i); -*M/,O
if(sHeader!=null) 'k{pWfn=<
{ 8{(;s$H~
if(sHeader.equals("Content-Length")) 59FAhEg
{ yL7a*C&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0!eZ&.h?4
break; NYm2fFPc
} q1.w8$
} y4w{8;Mh
else /P Qz$e-!Y
break; (kK6=Mrf
} #\GWYWkR
} a=.A/;|0*
catch(IOException e){e.printStackTrace ();} "z1\I\ ^
catch(Exception e){e.printStackTrace ();} $*\[I{Zau}
jyb/aov
Pp*|EW 1
Utility.log(nFileLength); WIa4!\Ky!
`h+sSIko
!X e
return nFileLength; wm%9>mA%
} OjCTTz
/608P:U
nNSq6 Cj
//保存下载信息（文件指针位置） soRt<83
private void write_nPos() _%?}e|epy
{ '+hiCX-_
try{ Pe6MDWR
output = new DataOutputStream(new FileOutputStream(tmpFile)); v2 T+I]I
output.writeInt(nStartPos.length); Q"h/o"-h
for(int i=0;i<nStartPos.length;i++) MRMswNQ
{ E=_M=5]
// output.writeLong(nPos); Mm;kB/1
output.writeLong(fileSplitterFetch.nStartPos); b*+Od8r
output.writeLong(fileSplitterFetch.nEndPos); /U4F\pZl
} A36dj
output.close(); K@)Hm\*
} EC<g7_0F
catch(IOException e){e.printStackTrace ();} 3P2H!r
catch(Exception e){e.printStackTrace ();} $Y5R^Y
} Fo|6 PoSo
jeFX?]Q
^i&sQQ({
//读取保存的下载信息（文件指针位置） a^hDxeG
private void read_nPos() xX.fN7[
{ k1e0kxn
try{ C!6?.\U/:c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P:eY>~m<;
int nCount = input.readInt(); f02<u
nStartPos = new long[nCount]; 8J-$+ ;
nEndPos = new long[nCount]; :G=N|3
for(int i=0;i<nStartPos.length;i++) "g;^R/sfq
{ b)"bX}
nStartPos = input.readLong(); t:B~P,r
nEndPos = input.readLong(); Rf||(KC<
} 6 9_etv
input.close(); A.8{LY;
} hsr,a{B%$
catch(IOException e){e.printStackTrace ();} A>8"8=C
catch(Exception e){e.printStackTrace ();} vq-Tq>
} ]:uJ&xUar
_Q_"_*e
xE`uFHuS}
private void processErrorCode(int nErrorCode) u(iEuF;7
{ |75>8;
System.err.println("Error Code : " + nErrorCode); F)Oe;z6
} Z7a~M3VnZ
P1tc*2Z
5v >0$Y{
//停止文件下载 r%\(5H f
public void siteStop() $lz\te
{ *8{PoD
bStop = true; :y^0]In
for(int i=0;i<nStartPos.length;i++) 'id]<<F
fileSplitterFetch.splitterStop(); puEuv6F
fTQRn
^Tgu]t
} dF$a52LS
} lO&TSPD^
//负责部分文件的抓取 Eh/B[u7T[
**FileSplitterFetch.java kcGs2Y_*&
*/ )!M %clm.
package NetFox; 7DQ{#Gf#G
Z.TYi~d/9D
pxy=edd
import java.io.*; ' P5ttI#|
import java.net.*; zg L0v5vk
{=};<;_F
E:'TZ4Z
public class FileSplitterFetch extends Thread { /qM:;:N%j
N.R,[K
*S,5
String sURL; //File URL mux_S2x9m\
long nStartPos; //File Snippet Start Position nW#UBtZ
long nEndPos; //File Snippet End Position *Y'nDv6_P
int nThreadID; //Thread's ID YL*yiZ9
boolean bDownOver = false; //Downing is over 4&]Sb}
boolean bStop = false; //Stop identical Jm0o[4
FileAccessI fileAccessI = null; //File Access interface .hO) R.
/E8{:>2
H&Jp,<\x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2 u:w
{ wtlIyE
this.sURL = sURL; >#~!03
this.nStartPos = nStart; 4B?8$&b
this.nEndPos = nEnd; $3.hZx>
nThreadID = id; av|r^zc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2wCTd:e:
} kYMKVR
2GB)K?1M
/BeA-\B
public void run() 2UqLV^ZY
{ EMK>7 aks
while(nStartPos < nEndPos && !bStop) $d\]s]}`
{ ^I2+$
mY!os91KoO
#2AKO/
try{ XL SYE
URL url = new URL(sURL); i~1bfl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fb8~2N"3
httpConnection.setRequestProperty("User-Agent","NetFox"); wNQhz.>y
String sProperty = "bytes="+nStartPos+"-"; ,n)f=q*%
httpConnection.setRequestProperty("RANGE",sProperty); 6jS:_[p
Utility.log(sProperty); #Xdj:T<*
A6-K~z^
M18<d1*
InputStream input = httpConnection.getInputStream(); L>:YGM"sL
//logResponseHead(httpConnection); D3,9X#B=
pYXusS7S
^&^~LKl~
byte[] b = new byte[1024]; _4~'K?
int nRead; ;.dyuKlI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) woI.1e5
{ r5#8Vzr
nStartPos += fileAccessI.write(b,0,nRead); Z]VmTB
//if(nThreadID == 1) m3Ma2jLWC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !mX-g]4E
} 2GRL`.1
:<Z>?x
mQ~0cwo)
Utility.log("Thread " + nThreadID + " is over!"); /<"<N<X
bDownOver = true; Y7q=]
//nPos = fileAccessI.write (b,0,nRead); B}OM:0
} Xx)PyO
catch(Exception e){e.printStackTrace ();} b# v+_7
} W.67};',
} A!xx#+M
@B e7"Fm
_'OXrT#Q
//打印回应的头信息 }wY6^JF
public void logResponseHead(HttpURLConnection con) Lt|'("($*
{ :oN$w\A
for(int i=1;;i++) jEaU;
{ <d`ksZ+
String header=con.getHeaderFieldKey(i); Jw-?7O
if(header!=null) MTyBGrs(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :_,oD
Utility.log(header+" : "+con.getHeaderField(header)); TAd~#jB9
else <4{Jm8zJ
break; uC2-T5n'
} 108cf~2&
} Qf=+%-$Y
on0MhW
r0xmDJ@y
public void splitterStop() ]; CTr0
{ DERhmJ;>H
bStop = true; V:Z}cfR.7
} L'A>IBrz
v%|S)^c?:
VyF|d?b
} >)+-:
3_5]0:?]-
h!yI(cY
/* 2*[Gm e
**FileAccess.java $27QY
*//文件访问(定位，写) N?Nu'
package NetFox; ;1gWz
import java.io.*; 8? U!PW
kuX{2h*`
655OL)|cD6
public class FileAccessI implements Serializable{ IH2V.>h
3=@lJ?Ym
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A ,$CYLj+
RandomAccessFile oSavedFile; 16cc9%
long nPos; Qo%IZw$l
/[<1D|f%
F4R0A6HL
public FileAccessI() throws IOException "kdmqvTHK0
{ @)^|U"
this("",0); X`s6lV%\
} ,SZYZ 25
O3*}L2j@
vAV{HBQ*
public FileAccessI(String sName,long nPos) throws IOException Kn#CIFbBN
{ C2a2K={
oSavedFile = new RandomAccessFile(sName,"rw"); Fk4T>8q2;
this.nPos = nPos; WL#E%6p[
oSavedFile.seek(nPos); !:^?GN#~x
} lL<LJ :L
f6$$e+
\OlB(%E7
public synchronized int write(byte[] b,int nStart,int nLen) 9CNeMoA$p:
{ Droa1_FX
int n = -1; `|2p1Ei
try{ zKllwIfi
oSavedFile.write(b,nStart,nLen); .@`5>_
n = nLen; <Na .6P
} z&Kh$ $)[
catch(IOException e) y$Rh$eK
{ N"zg)MsX
e.printStackTrace (); EvJ<X,Bo
} 0e,U&B<W
t(.jJ>|+*
<aRsogu"P
return n; #-<n@qNg[
} RF|r@/S
4))5l9kc.
*U}cj A:ZN
} W|I<hY\X
:G8:b.
]IM/R@
/* E=&":I6O
**SiteInfoBean.java 04E S>'@
*/ ,bRYqU?#0
package NetFox; VLP'3 qX
Sdr,q9+__
ZQ)vvD<
public class SiteInfoBean { OTmw/#ug
']__V[
G5T(
private String sSiteURL; //Site's URL $*S&i(z
private String sFilePath; //Saved File's Path nYE''g+x
private String sFileName; //Saved File's Name F5s`AjU
private int nSplitter; //Count of Splited Downloading File ;/R\!E
}7+`[g
"IA:,j.#g
public SiteInfoBean() tm|YUat$]r
{//nSplitter的缺省值为5 LUfo@R
//default value of nSplitter is 5 6-t:eo9
this("","","",5); 9H%dK^C
} OBEHUJ5
o @(.4+2m
iQ8T3cC+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) szw|`S>o
{ ph~d%/^jI
sSiteURL= sURL; 3DX@ggE2
sFilePath = sPath; 4SNDKFw
sFileName = sName; 3:mZ1+
this.nSplitter = nSpiltter; s*9lYk0
T/nG\WZbZn
^o-)y"GJ
} D6vhW:t8?
w^=uq3X?
M=t;t0
public String getSSiteURL() :\cid]y3
{ qbq.r&F&
return sSiteURL; -& T.rsp
} bqcwZ6r<
Fu\!'\6
OeYZLC(
public void setSSiteURL(String value) Rz:1(^oA
{ {osadXdC
sSiteURL = value; i~i ?M)
} >mUSRf4
lDVw2J'p
}Q-%ij2
public String getSFilePath() Gg# 1k TK
{ J_}Rsp ED
return sFilePath; iVZX
} o!Y61S(
xWxgv;Ah
Sh;Z\nj
public void setSFilePath(String value) u_'XUJ32!
{ )tp;2rJ/
sFilePath = value; 3\Tqs
} {D`_q|
s#4Q?<65u
%j. *YvveW
public String getSFileName() #QM9!k@9k
{ =j^wa')
return sFileName; rL23^}+^`
} `-yiVUp1:z
1{$=N2U
)F3>
public void setSFileName(String value) 5XF&yYWq
{ wfq}NK;
sFileName = value; * amZ
} "YoFUfaNg
Z11I1)%s
}_,={<g
public int getNSplitter() L5n/eg:Q
{ xW+XN`77
return nSplitter; }S=m: VKH
} @ev8"JZ1
aFd87'^
Zd~Q@+sH
public void setNSplitter(int nCount) E, ;'n
{ 5.U4P<qS
nSplitter = nCount; Mp_SL^g|
} ^wW{7Uq>
} kPezR: 31
fK;I0J
4)].{Z4q
/* V\P .uOI
**Utility.java 5z@QAQ
*/ (AswV7aGe
package NetFox; ZeE(gtM
b.mWB`59
!I+F8p
public class Utility { Np>0c-S
k!ac_}&NNv
sUN9E4
public Utility() XEb+Z7L1
{ T&u25"QOf
B/gI~e0
H5/w!y@
} WF`
NUM+tg>KM
//线程睡眠 ;s!GpO7+
public static void sleep(int nSecond) #/o1D^
{ G&@vTcF
try{ P.'$L\
Thread.sleep(nSecond); naiy] oY"
} aB)G!Rm&
catch(Exception e) @i>o+>V
{ )O$T; U
e.printStackTrace (); NzC&ctPk
} w(UZmZb}
} oG' 'my#3
=0mXTY1
//日志 $x;(C[
public static void log(String sMsg) &O|qx~(
{ UmOK7SPi
System.err.println(sMsg); pL`)^BJ
} z2god 1"
(/gMtIw
)g[7XB/w
public static void log(int sMsg) yPT\9"/
{ mJa8;X!r6
System.err.println(sMsg); *ez7Q
} M(#]NTr ~4
} YnW,6U['{g
eDL0Vw
g#r,u5<*?
/* ~vstuRRST
**TestMethod.java 41^ $
*/ Ep8 y
package NetFox; MURHv3
Z.3*sp0 yv
$##LSTA
public class TestMethod { X,ok3c4X
"xp>Vj
*%jd>e7d
public TestMethod() *FC26_pH
{ ///xx/weblogic60b2_win.exe EQ2HQz]
try{ v0,&wdi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); e|Mw9DIW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $X]Z-RCK3
SiteFileFetch fileFetch = new SiteFileFetch(bean); R*>EbOuI
fileFetch.start(); Yy4l -}"
} 0w ;#4X:m
catch(Exception e){e.printStackTrace ();} w02t9vz
Ujfs!ikh&F
vlx\hJ<I
} d1hXzJs
#b+>O+vx8
aKk0kC
public static void main(String[] args) "-A@d&5.
{ `!7QegJa"
new TestMethod(); oxJ#NGD
} ^|lG9z%Foy
} 02mu%|"
点击下载更多相关资料