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)); i[N=.
} g?1! /+
for(int i=0;i<nEndPos.length-1;i++) av:9kPKm
{ 9J(jbJ7p
nEndPos = nStartPos[i+1]; D6NgdE7b
} H"vy[/UcR
nEndPos[nEndPos.length-1] = nFileLength; KwxO%/-}S
} LO@='}D=
} M\L^ Wf9
uk<JV*R=
nm{J
//启动子线程 qP4vH]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; haoQr)S
for(int i=0;i<nStartPos.length;i++) Sf"]enwB
{ oRZ--1oR_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;cfmMt!QWJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Re]7G.y
nStartPos,nEndPos,i); s+7#TdhA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -+,3aK<[
fileSplitterFetch.start(); i8+[-mh
} :@c\a99Kx
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VqBb=1r%o7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t(Sjo8, b
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mZ!1Vh
nEndPos = " + nFileLength); N[j*Q 8X_
// fileSplitterFetch[nPos.length-1].start(); dHJ#xmE!pP
o^*k
W"&Y7("y
//等待子线程结束 Qk#`e
//int count = 0; Izr_]%
//是否结束while循环 )zYm]\@
boolean breakWhile = false; 2nkUvb%=
Ce-D^9kC
%D $+Z(
while(!bStop) uYy&<_r
{ K'u66%wAL
write_nPos(); Ow f:Kife
Utility.sleep(500); l6z}D;4
breakWhile = true; @yxF/eeEy+
nhb: y
JR^#NefJ
for(int i=0;i<nStartPos.length;i++) L.R4 iN
{ ZT1IN6;8W
if(!fileSplitterFetch.bDownOver) &vHfuM`
{ S*9qpes-m|
breakWhile = false; Lcow2 SbH
break; EN/e`S$)
} +L>?kr[i[
} p*OpO&oodu
if(breakWhile) ]aqg{XdGt
break; EI!e0V1!
ai@hQJ*
jc-$l
//count++; SZ3UR
//if(count>4) rQM$lJ[x
// siteStop(); ml\2%07
} Aat-938FP6
zilM+BZ8
m%[`NP (
System.err.println("文件下载结束！"); 1?hx/02
} ,'c?^ $J|z
catch(Exception e){e.printStackTrace ();} p|,3X*-ynx
} 2Pz)vnV"
2uy<wJE>
7'1 +i
//获得文件长度 lk`,s
public long getFileSize() _DAj$$ Ru4
{ 9W+RUh^W
int nFileLength = -1; %SJ2W>e
try{ KVA~|j B
URL url = new URL(siteInfoBean.getSSiteURL()); 5ON\Ve_H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 22_%u=p-|
httpConnection.setRequestProperty("User-Agent","NetFox"); h.WvPZ2U
6-!U\R2Z>
=}^J6+TVL
int responseCode=httpConnection.getResponseCode(); T=D|jt
if(responseCode>=400) (>usa||
{ 9fQFsI
processErrorCode(responseCode); *Z:'jV<
return -2; //-2 represent access is error 5*P+c(=
} @M_p3[c\
b<1+q{0r
s%xhT
String sHeader; "B"Yfg[
I?Fv!5p
yhzZ[vw7k
for(int i=1;;i++) 6(as.U>K
{ ^p}|""\j
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rmh 1.W
//Utility.log(in.readLine()); L^><APlX
sHeader=httpConnection.getHeaderFieldKey(i); fq,LXQ#G
if(sHeader!=null) m&!4*D
{ 5zk^zn)
if(sHeader.equals("Content-Length")) @&fAR2
{ guc[du
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _Cnl|'
break; }{#ty uzAo
} R m^$Dn
} U\~9YX8
else PTZ/jg@71
break; S#{gCc
} `j)S7KN
} !eE;MaS>
catch(IOException e){e.printStackTrace ();} W _JGJV.^f
catch(Exception e){e.printStackTrace ();} ) u Sg;B4
m?)REE
}XcYIo#+t
Utility.log(nFileLength); o.|P7{v}
@B#\3WNt
t'{IE!_
return nFileLength; Z\. n6
} %!X9>i>
6zR9(c:a~
g*]/HS>e<G
//保存下载信息（文件指针位置） CaE1h9
private void write_nPos() 6#gS`X23Y
{ ]qpLaBD
try{ TG^?J`
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7G]v(ay
output.writeInt(nStartPos.length); '^10sf`"
for(int i=0;i<nStartPos.length;i++) Ql8s7%
{ :XFr"aSt
// output.writeLong(nPos); n> tru L
output.writeLong(fileSplitterFetch.nStartPos); 0s'h2={iI
output.writeLong(fileSplitterFetch.nEndPos); 1XXuFa&
} G~mLc
output.close(); 3[F9qDAy
} @]F1J
catch(IOException e){e.printStackTrace ();} j0`)mR}
catch(Exception e){e.printStackTrace ();} 3Z%~WE;I
} )Bw}T
2&o jQhe
w]O[{3"
//读取保存的下载信息（文件指针位置） "&Rt&S
private void read_nPos() o|G[/o2
{ iO@UzD#v
try{ ;Y9-0W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dtx3;d<NsJ
int nCount = input.readInt(); U]AJWC6
nStartPos = new long[nCount]; n4sO#p)'
nEndPos = new long[nCount]; KBOp}MEz
for(int i=0;i<nStartPos.length;i++) *YO^+]nmY
{ M~eXC
nStartPos = input.readLong(); $H8B%rT]
nEndPos = input.readLong(); i9koh3R\
} N}gPf i
input.close(); PrqyJ
} @s.civ!Yk
catch(IOException e){e.printStackTrace ();} H ]z83:Z
catch(Exception e){e.printStackTrace ();} 8yDe{
} J~.`
fW=vN0Z
L+.&e4f'oj
private void processErrorCode(int nErrorCode) 7SJR_G6,{
{ 4&kC8 [r
System.err.println("Error Code : " + nErrorCode); #1De#uZ
} Ms 3Sri
zvbO q
/Os6i&;
//停止文件下载 SceK$
public void siteStop() (L<qJd1Q
{ pf$gvL
bStop = true; eXQLE]L]
for(int i=0;i<nStartPos.length;i++) rU9z? (
fileSplitterFetch.splitterStop(); p|+TgOYOc
0,whTnH|
D/YMovH%
} {n\Ai3F-
} SA?lDRF
//负责部分文件的抓取 U8zCV*ag
**FileSplitterFetch.java ;-AC}jG
*/ Nsn~mY%
package NetFox; i_(6}Y&
HtV8=.^
i__f%j`!W
import java.io.*; MfZamu5+F
import java.net.*; 0bG#'.-
Ao+6^z_
wxo*\WLe
public class FileSplitterFetch extends Thread { [Ob09#B%:5
Tq?7-_MLC$
k+BY3a
String sURL; //File URL *,|x p
long nStartPos; //File Snippet Start Position E#R1
long nEndPos; //File Snippet End Position mw&'@M_(7
int nThreadID; //Thread's ID U"RA*|
boolean bDownOver = false; //Downing is over Z!-V&H.
boolean bStop = false; //Stop identical [,3E#+y
FileAccessI fileAccessI = null; //File Access interface #mYe@[p@
a+RUSz;DL
)#8}xAjV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6of9lO:
{ iG#92e4
this.sURL = sURL; U(gYx@
this.nStartPos = nStart; 2wu\.{6Zp
this.nEndPos = nEnd; 0t[ 1#!=k
nThreadID = id; *q"1I9zvT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T+q5~~\d
} w75Ro6y
0V?7'Em
^WF_IH&
public void run() P?^%i
{ k t'[
while(nStartPos < nEndPos && !bStop) %(|-+cLW+
{ [dFe-2u ,$
]ddH>y&o
Vqcw2
try{ 8"TlWHF`
URL url = new URL(sURL); 4V c``Um
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +IMt$}7[
httpConnection.setRequestProperty("User-Agent","NetFox"); Jd~Mq9(
String sProperty = "bytes="+nStartPos+"-"; k!bG![Ie|
httpConnection.setRequestProperty("RANGE",sProperty); |qVM`,%L
Utility.log(sProperty); m&yHtnt
hXvC>ie(i
"[-W(=
InputStream input = httpConnection.getInputStream(); ?9%$g?3Z
//logResponseHead(httpConnection); V>`9ey!U
~k%XW$cV
6VS_L@
byte[] b = new byte[1024]; S=W^iA6>
int nRead; 6q8PLyIp
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1;PI%++
{ (>,b5g
nStartPos += fileAccessI.write(b,0,nRead); nBLb1T
//if(nThreadID == 1) XD" 4t4~>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9R">l5u
} R#i`H(N
bN6i*)}
tt CC] Q
Utility.log("Thread " + nThreadID + " is over!"); bc:3 5.
bDownOver = true; nN^lY=3
//nPos = fileAccessI.write (b,0,nRead); ~1aM5Ba{
} x0%yz+i{:
catch(Exception e){e.printStackTrace ();} <EdNF&S-
} f]mVM(XZN
} 9-vQn/O^D
CMyz!jZ3
e+<|
//打印回应的头信息 G*,7pc
public void logResponseHead(HttpURLConnection con) 3[m2F O,Z
{ t BG 9Mn
for(int i=1;;i++) U(Bmffn4Z
{ 7G7"Zule*j
String header=con.getHeaderFieldKey(i); |WpJen*?Y
if(header!=null) ;)SWwhQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ur7S K(#
Utility.log(header+" : "+con.getHeaderField(header)); rVRv*W
else R,BINp
break; <>Ha<4A =E
} NTO.;S|2%
} mg>wv[ 7
CJDNS21m
mxu!$wx
public void splitterStop() Kr<UPr
{ <r(D\rmD
bStop = true; ks %arm&
} 1 .[OS
Oqt{ uTI~
US"UkY-\
} "!fwIEG
HuKOb4g
m8G/;V[x
/* 0LSJQ9\p
**FileAccess.java [0]J 2
*//文件访问(定位，写) cct/mX2&~
package NetFox; ie>mOsz
import java.io.*; F-M)6&T
5R%y3::$S
s?&S<k-=fr
public class FileAccessI implements Serializable{ ?<5KLvGv
ZR"qrCSw`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IS`ADDU[S
RandomAccessFile oSavedFile; rx@i.+
long nPos; QC&,C}t,
?Iij[CbU
;Bw3@c
public FileAccessI() throws IOException (ip3{d{CT]
{ jGo\_O<of
this("",0); /[ft{:#&t
} -v|lM8
-}( o+!nl
Kb-m
public FileAccessI(String sName,long nPos) throws IOException ^#K^WV
{ )K`tnb.Pf
oSavedFile = new RandomAccessFile(sName,"rw"); 4x?I,cAN
this.nPos = nPos; A:(qF.Tm
oSavedFile.seek(nPos); 52,'8` ]
} R6:m@
ne3t|JZ
'A\0^EvVv
public synchronized int write(byte[] b,int nStart,int nLen) 1jAuW~
{ ?'"BX
int n = -1; %K7;ePu
try{ \OWxf[
oSavedFile.write(b,nStart,nLen); }w2Et
n = nLen; ;B(16&l=q
} Asq&Z$bB_
catch(IOException e) L|1~'Fz#w
{ -7o-d-d F
e.printStackTrace (); sJl>evw
} |z&7KoYK'
Y%@;\
RyM29uD
return n; l|vT[X/g
} ] \!,yiVeU
Gl6:2
!YlEXaS
} /^I!)|At
;TwqZw[.
TIaiJvo
/* p6)6Gcx
**SiteInfoBean.java Bsd~_y}8
*/ ljz=u;O)
package NetFox; +%~me?
N+H[Y4c?F&
g2 mq?q(g
public class SiteInfoBean { BJLeE}=H
&zVXd
HzuG- V
private String sSiteURL; //Site's URL A2\3.3
private String sFilePath; //Saved File's Path f9IqcCSW
private String sFileName; //Saved File's Name }*aj&
private int nSplitter; //Count of Splited Downloading File YhooD,[.
!|9k&o
f}ch1u>
public SiteInfoBean() D`.\c#;cN
{//nSplitter的缺省值为5 YfseX;VX
//default value of nSplitter is 5 CWB<I
this("","","",5); "+ k}#<P4\
} u09D`QPP]
&g0r#K
l2wu>Ar7.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b.}J'?yLm
{ W3^^aD-
sSiteURL= sURL; ="Azg8W
sFilePath = sPath; (hRg0Z=
sFileName = sName; kK0zb{
this.nSplitter = nSpiltter; J@IKXhb7_
')2LP;(
' 8Q}pp`
} c`\qupnY
3#\C!T0y
55,2eg#{O
public String getSSiteURL() XXD4T9Wy
{ 77]lpmC
return sSiteURL; 0j}@lOt(
} ;rnhv:Iw
1&Mpx!K*T
Wrt5eYy
public void setSSiteURL(String value) a\B?J
{ 3J3wKw!`
sSiteURL = value; 9c5DEq
} 6\y?+H1
)<e,-XujY
GNW.n(a
public String getSFilePath() GK3cQw
{ o+- 0`!yj
return sFilePath; "=$uv
} muhu` k`C
y~VLa
/NuO>kQa
public void setSFilePath(String value) ?-<>he
{ F9r|EU#;
sFilePath = value; )L_@l5l
} 7dR]$~+*e
^^YP kh6sS
P"[{s^mb
public String getSFileName() o,$K=#Iv
{ oTTE<Ct[
return sFileName; $j4/ohwTDY
} 2cZgG^
`y{[e j
}5Km \OI
public void setSFileName(String value) $9W,1wg
{ bJw{U.
sFileName = value; P\@efq@!
} 3k/X;:,.
VLfKN)g
FB3}M)G>M
public int getNSplitter() D23 c/8K
{ }yd!UU
return nSplitter; fW=eB'Sl
} @S&QxE^
XXXQAY-,C
B!4~A{
public void setNSplitter(int nCount) Sb}=j;F
{ +{%)}?F
nSplitter = nCount; j&q%@%Gm
} ghTue*A
} K :>O X
T5dnj&N ]
[7,q@>:CS
/* q-/t?m0
**Utility.java h"f_T [
*/ lx> ."rW
package NetFox; 8KsPAK_
N%)q.'M
Sf2xI'
public class Utility { ,G[Y< ~Hy
}-T,cA_H|
s|k&@jH)
public Utility() }:!X@C~
{ )G*xI`(@
xrv0%
wVc^l
} @E>I<j,D
g|tclBx
//线程睡眠 2G_]Y8
public static void sleep(int nSecond) )^ PWr^
{ msQ?V&+<
try{ d-z[=1m
Thread.sleep(nSecond); %8xKBL]J
} Q(x/&]7=V
catch(Exception e) SF da?>
{ >Sb3]$$
e.printStackTrace (); bRr3:"=sE
} `^|l+TJG
} aj<r=
^z51f>C
//日志 rE0%R+4?
public static void log(String sMsg) ZKM@U?PK
{ AS'+p%(
System.err.println(sMsg); R*2F)e\|
} [2!C^\t
FrE#l.)?!
Mh{>#Gs
public static void log(int sMsg) l(\F2_,2W
{ R*r"};
System.err.println(sMsg); }y vH)q
} \ _?d?:#RD
} #$F*.vQSs+
k$>5v +r0
#w:nj1{_
/* *]nk{jo2
**TestMethod.java ls~9qkAyLx
*/ 0%)T]SDS
package NetFox; >]uu?!PU
EV7lgKM^
gdq6jz
public class TestMethod { 7k00lKA\w
d]MpE9@'v
ce; zn\
public TestMethod() e3?z^AUXm
{ ///xx/weblogic60b2_win.exe Y?L>KiM$
try{ ^;tB,7:*V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nzbAQ3v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =^\?{oV
SiteFileFetch fileFetch = new SiteFileFetch(bean); f>|<5zm#<
fileFetch.start(); zg$ag4%Qgg
} ~Yc!~Rz
catch(Exception e){e.printStackTrace ();} [ako8
%0Qq~J@Lu
(/s~L*gF{
} TKgN31`
*z.rOY= 8
_dmG#_1
public static void main(String[] args) ]2 $T 6
{ Et0)6^-v
new TestMethod(); [HL>Lp&A?
} M?GkHJ%!
} UtQCTNjC{
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