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)); '7el`Ff
} !2.BLJE>
for(int i=0;i<nEndPos.length-1;i++) vio>P-2Eho
{ $Q8 &TM}E
nEndPos = nStartPos[i+1]; uOLShNo
} =/46;844T
nEndPos[nEndPos.length-1] = nFileLength; ').)0;
} }q@#M8b
} z``wqK
MXcW &b
\\<=J[R.M
//启动子线程 T8z?_ *k
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !`I@Rk]`c
for(int i=0;i<nStartPos.length;i++) E|f[#+:+
{ f; |fS~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zVw5(Tc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rnj$u-8
nStartPos,nEndPos,i); K#wA ;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <Pt?N2]A|
fileSplitterFetch.start(); Yu3S3aRE
} PtbaC6"\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Vz/w.%_g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #mu L-V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F,p0OL.
nEndPos = " + nFileLength); U*$P"sS`
// fileSplitterFetch[nPos.length-1].start(); >Dr(%z6CN
nFEJO&1+
0Xh_.PF
//等待子线程结束 ~#*C,4m
//int count = 0; =9a2+v0
//是否结束while循环 b/z-W`gw
boolean breakWhile = false; Bxm,?=h
>5~#BrpwG
\QK@wgu
while(!bStop) Kk8}m;
{ LN5LT'CE
write_nPos(); $5&%X'jk
Utility.sleep(500); #,d~t
breakWhile = true; K4!-%d$
}UW7py!TN
(E0
for(int i=0;i<nStartPos.length;i++) &ry*~"xoh
{ |q77
if(!fileSplitterFetch.bDownOver) ~:z.Xu5m
{ [b3!H{b#
breakWhile = false; `Y?VQ~ci>
break; -XV,r<''
} e,p"=/!aY
} sxREk99lL
if(breakWhile) l'+3 6
break; +NPL.b|
tUv>1) [
hC:'L9Y
//count++; ,&t+D-s<f
//if(count>4) ebk>e*
// siteStop(); At(88(y-W
} g<:Lcg"u
?gE=hh
XQ]K,# i
System.err.println("文件下载结束！"); ]ZY2\'
} xo"GNFh!
catch(Exception e){e.printStackTrace ();} ;t&q|}x"
} r6m^~Wq!}
ob.<j
k)p`x"To
//获得文件长度 !Z!)$3bB
public long getFileSize() q#K{~:
{ vhrf89-q
int nFileLength = -1; (g##wa)L
try{ AjVC{\Ik
URL url = new URL(siteInfoBean.getSSiteURL()); t%=7v)IOE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r6DLShP-Ur
httpConnection.setRequestProperty("User-Agent","NetFox"); :;k?/KU7
;,4*uU'vq
Nm*(?1
int responseCode=httpConnection.getResponseCode(); )pWgt5:7~
if(responseCode>=400) 9z7_D_yN2
{ NdXHpq;
processErrorCode(responseCode); *QC6zJ
return -2; //-2 represent access is error `a83RX_\
} w 3t,S3!
n1-p/a.
Xoe|]@U`
String sHeader; 7H7 Xbi@
RHF"$6EAFG
@.t +
for(int i=1;;i++) 5nG\J g7
{ PUdv1__C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `~GXK
//Utility.log(in.readLine()); "-4|HA
sHeader=httpConnection.getHeaderFieldKey(i); C;BO6$*_e
if(sHeader!=null) k6tCfq;
{ 'P.y?
if(sHeader.equals("Content-Length")) L!Jx`zM^
{ ~;"eNg{T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2I.FSR_G?
break; uyj!$}4
} #7uH>\r
} Ia2WBs=
else _J,**AZ~z
break; 1iT_mtXK$
} 8FsQLeOE
} -)A:@+GF
catch(IOException e){e.printStackTrace ();} nW=6nCyvo
catch(Exception e){e.printStackTrace ();} g\aO::
</I%VHP,[f
bmT%?it
Utility.log(nFileLength); (hc!!:N~q
uKx:7"KD
m#+0m!
return nFileLength; Qf:e;1F!
} #$WnMJ@
@nH3nn
@rhS[^1wi+
//保存下载信息（文件指针位置） %Wtf24'o;v
private void write_nPos() M"z=114
{ 2CC"Z
try{ rJ/HIda
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ar%*NxX
output.writeInt(nStartPos.length); Au2^ T1F
for(int i=0;i<nStartPos.length;i++) -jjB2xP
{ ?V`-z#y7
// output.writeLong(nPos); =Uk#7U"P
output.writeLong(fileSplitterFetch.nStartPos); 49"C'n0wST
output.writeLong(fileSplitterFetch.nEndPos); -x?Z2EA!
} '6D"QDZB
output.close(); +Xg:*b9So
} =eA|gt
catch(IOException e){e.printStackTrace ();} /KH85/s
catch(Exception e){e.printStackTrace ();} A!Tl
} TG=A]--_a
dV$[O`F*b
LJrH_h8C
//读取保存的下载信息（文件指针位置） >W >Ei(f
private void read_nPos() +XO\#$o>W
{ VJTO:}Q
try{ p[xGL } +\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K,! V _
int nCount = input.readInt(); 8kdJtEW3
nStartPos = new long[nCount]; A-uIZ zC
nEndPos = new long[nCount]; VZr:yE
for(int i=0;i<nStartPos.length;i++) -@_v@]:
{ y9d"sqyh
nStartPos = input.readLong(); \5!7zPc
nEndPos = input.readLong(); 1,;zX^
} y2jw3R
input.close(); 2'-"&d+O
} NNbdP;=:u
catch(IOException e){e.printStackTrace ();} 2YKa <?_
catch(Exception e){e.printStackTrace ();} I-g/)2
} j:'g*IxM_
6MY<6t0a
6*>Lud
private void processErrorCode(int nErrorCode) *n EkbI/
{ /; Bmh=
System.err.println("Error Code : " + nErrorCode); RQo a
} n}A!aC
!YjxCx
<C(o0u&/
//停止文件下载 0stc$~~v
public void siteStop() qT(6TP
{ u)<s*jk
bStop = true; cXqYO|3/M
for(int i=0;i<nStartPos.length;i++) Z#H<+S(
fileSplitterFetch.splitterStop(); ]nB|8k=J
$+7uB-KsU
KB](W
} U3V5Jor#
} Su2{nNC>
//负责部分文件的抓取 Q7XOO3<):
**FileSplitterFetch.java 1\&j)3mC
*/ ySmbX
package NetFox; edq,:
u>"0>U
pCh v;
import java.io.*; ={ms@/e/T
import java.net.*; V9v20iX
&R%'s1]o
qtZ? kJ
public class FileSplitterFetch extends Thread { rYr*D[m]
'q)g,2B%
jhm??Af
String sURL; //File URL )|lxzlk
long nStartPos; //File Snippet Start Position MY@&^71i4
long nEndPos; //File Snippet End Position }<0N)dpT
int nThreadID; //Thread's ID >SK:b/i
boolean bDownOver = false; //Downing is over |R0f--;
boolean bStop = false; //Stop identical w]0@V}}u$o
FileAccessI fileAccessI = null; //File Access interface ;Y^'$I2fR#
T^1 Z_|A
E7MSoBX9M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~Ba=nn8Cq
{ *i]?J
this.sURL = sURL; {?H5Pw>{%h
this.nStartPos = nStart; f0P,j~]
this.nEndPos = nEnd; 2TGND-(j
nThreadID = id; |X@s {?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zY/Oh9`=v
} tav@a)
t?9J'.p
HS|Gz3~
public void run() .u mqyU~
{ x<I[?GT=
while(nStartPos < nEndPos && !bStop) h;q&B9
{ dOv\]
QPm[4Fd{G
"E+;O,N-
try{ GP+=b:C{E
URL url = new URL(sURL); H!Gw@u]E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U-DQ?OtmC@
httpConnection.setRequestProperty("User-Agent","NetFox"); {N]WVp*R
String sProperty = "bytes="+nStartPos+"-"; 5QqU.9M
httpConnection.setRequestProperty("RANGE",sProperty); >r`O@`^U
Utility.log(sProperty); '=nmdqP
'A|c\sy
ou0TKE9 _
InputStream input = httpConnection.getInputStream(); |ufT)+:
//logResponseHead(httpConnection); }@LIb<Y
r)~?5d
}V]*FCpQ
byte[] b = new byte[1024]; RF*>U a
int nRead; c) Eu(j\#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qt.4dTd:_
{ `XF[A8@h
nStartPos += fileAccessI.write(b,0,nRead); !84Lvg0&
//if(nThreadID == 1) Q@}SR%p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sDs.da#*2
} Mxw-f4j
Xc+YoA0Ez
xJw" 8V<
Utility.log("Thread " + nThreadID + " is over!"); n',7=~
bDownOver = true; 6 wd
//nPos = fileAccessI.write (b,0,nRead); 0#GnmH
} Q}Ah{H0C
catch(Exception e){e.printStackTrace ();} cFie;k
} ()j)}F#Z`
} N@_y<7#C
7kD?xHpe
Ng<ic
//打印回应的头信息 K?M~x&Q
public void logResponseHead(HttpURLConnection con) c611&
{ S7J.(; 82
for(int i=1;;i++) 7V^j9TC
{ \1-lda
String header=con.getHeaderFieldKey(i); dH0>lV
if(header!=null) ?lqqu#;8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Nq9pory^
Utility.log(header+" : "+con.getHeaderField(header)); m.6uLaD"!}
else Dd0yQgCu
break; R4)l4rnO
} ,h%n5R$:
} K HNU=k
})!-
lpd~U2&
public void splitterStop() ZH=Bm^
{ PRYm1Y
bStop = true; AvIheR
} W@GU;Nr
VwBw!,%Ab
e7iQG@i7
} b+RU <qR
{a>JQW5=
p? +!*BZ
/* j AoI`J
**FileAccess.java mGwJ>'+d
*//文件访问(定位，写) <b4} B
package NetFox; zB7^L^Y
import java.io.*; D}{]5R
(.z0.0W
OvC@E]/+
public class FileAccessI implements Serializable{ ]9<H[5>$R
$Y$s*h_-/<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b!QRD'31'j
RandomAccessFile oSavedFile; 5^qs>k[mN
long nPos; B'B0e`
qbD_
b V_<5PHP
public FileAccessI() throws IOException K^/.v<w
{ 2 =>3B
this("",0); IAmMO[9H
} CJ3/8*;w
O#^qd0e'P!
RY,L'GtO
public FileAccessI(String sName,long nPos) throws IOException djdSD
{ EcR[b@YI
oSavedFile = new RandomAccessFile(sName,"rw"); qIy9{LF
this.nPos = nPos; w(Mi?
oSavedFile.seek(nPos); C-Y7n5
} ldKLTO*&
tuo'Uk)
=(<7o_gJ
public synchronized int write(byte[] b,int nStart,int nLen) +miL naO~L
{ OtZtl*5
int n = -1; FGo)]U
try{ I=E\=UTG,5
oSavedFile.write(b,nStart,nLen); Pl|*+g
n = nLen; t/]za4w/
} 7pH[_]1"
catch(IOException e) P6'0:M@5
{ @a]`C $6
e.printStackTrace (); PB:r+[91
} m}m|(;T
^'vWv C
O4W2X@
return n; n>lQ:l~
} kgX"I ?>d
Ban"H~
Je#3
} .6i +_B|
$yZP"AsAR
y$|OE%S
/* #/K71Y
**SiteInfoBean.java {*Qx^e`h$.
*/ cn ;2&
package NetFox; $O9#4A;
!`dn# j
< $rXQ
public class SiteInfoBean { ~HX'8\5
)]JQlm:H
38RyUHL=
private String sSiteURL; //Site's URL <*4r6UFR
private String sFilePath; //Saved File's Path -fx$)d~
private String sFileName; //Saved File's Name Xu[A,6
private int nSplitter; //Count of Splited Downloading File wIQt f|ZI>
z0tm3ovp
YR~)07
public SiteInfoBean() ?CuwA-j
{//nSplitter的缺省值为5 0 !F!Y_
//default value of nSplitter is 5 u+]8Sq
this("","","",5); `HM?Fc58
} eq36mIo
`c_Wk]i
?7aeY5p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k Rp$[^ma
{ &;%LTF@I,
sSiteURL= sURL; ohB@ijC!
sFilePath = sPath; !JwR[X\f
sFileName = sName; h!]=)7x;
this.nSplitter = nSpiltter; >VvA&p71b
e:WKb9nT
>o!~T}J7
} ,tHV H7[
fUS1`
/.[78:G\,
public String getSSiteURL() lyyRyFfQ
{ FO xZkU\e=
return sSiteURL; !&vPG>V
} 5*Y(%I<
.d%CD`8!
Zm/I&
public void setSSiteURL(String value) :0j_I\L
{ ~~3 BV,
sSiteURL = value; 76cLf~|d~
} 4i7+'F
f0&%
&P7Z_&34Z
public String getSFilePath() _;M3=MTM9
{ {B-*w%}HU
return sFilePath; Y'C1L4d
} o$Ju\(Y$<+
Z+=M_{`{
s }Ql9
public void setSFilePath(String value) rCUGaf~
{ BU#3fPl
sFilePath = value; dTjDVq&Hz
} p(6 sN=
s'|t2`K("
?4^ 0xGyE
public String getSFileName() />6ECT
{ T+e*'<!O
return sFileName; 5] LfJh+"n
} (x fN=Te,-
lvs XL
ToXWFX
public void setSFileName(String value) )ZG;.j
{ -aoYoJ '
sFileName = value; {Su?*M2y
} ]?eZDf~
Q]:O#;"<
diq}\'f
public int getNSplitter() K:PH:e
{ jjs/6sSRk
return nSplitter; z:Ml;y
} t un}rdb
(o^tmH*
F^i3e31*t
public void setNSplitter(int nCount) 1|bXIY.J*
{ LD$5KaOW
nSplitter = nCount; 9mF'
} jkAjYR.
} S$6|KY u
Ma YU%h0
j#NyNv(jE1
/* JzyCeM =
**Utility.java fqNh\~kja
*/ %()d$.F
package NetFox; X8Z?G,[H
FXQWT9Kk~_
P"YdB|I
public class Utility { wq)*bIv
i'>6Qo
48^-]};
public Utility() '\:4Ijp<"
{ om3 %\
`MtzA^Xr
Ltlp9 S
} rTPgHK]?l
XJ18(Q|w'
//线程睡眠 @CprC]X
public static void sleep(int nSecond) @Jt$92i5PS
{ *t@A-Sn
try{ ]a $6QS
Thread.sleep(nSecond); du65=w4E!
} d?,'$$aB
catch(Exception e) inP2y?j
{ :@A&HkF
e.printStackTrace (); }:Z.g
} Y:^hd809
} /6x&%G:m#
["-rDyP
//日志 bA;OphO(
public static void log(String sMsg) 3I)~;>meo
{ l;?:}\sI=
System.err.println(sMsg); mF4W4~"
} l:HQ@FX
7?P'f3)fG
``MO5${
public static void log(int sMsg) *x36;6~W;
{ byHc0ktI\
System.err.println(sMsg); L/k35x8
} L.n@;*
} MZgaQUg
hkK>h
73Dxf -
/* 7?.uAiM'zT
**TestMethod.java ^<;W+dWdU
*/ P1#g{f
package NetFox; L&\W+k
-[mmT'sS
OC! {8MR
public class TestMethod { ~q>jXi
I?T !
x]^d'o:cDP
public TestMethod() wL;OQhI
{ ///xx/weblogic60b2_win.exe N,`@Q7
try{ 7nt(Rtbsu
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z+xkN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .k#PrT1C
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,&[o:jTk
fileFetch.start(); c <TEA
} x{H+fq,M
catch(Exception e){e.printStackTrace ();} <spG]Xa<
~WrpJjI[
[R]V4Hb
} 2;)IBvK
=?]`Xo,v~
lMv6QL\>'
public static void main(String[] args) 1P)K@j
{ VL#:oyWA
new TestMethod(); Zpd-ob
} Dj/Hz\
} ju2H0AQ
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