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)); W NCdk$
} xE:p)B-]
for(int i=0;i<nEndPos.length-1;i++) :v+39
{ zB4gnVhus|
nEndPos = nStartPos[i+1]; juM?y'A
} H~&'`h1
nEndPos[nEndPos.length-1] = nFileLength; !^%b|=[
} :DEZ$gi
} mOBS[M5*
zc_3\N
1 OX(eXF>
//启动子线程 @YRBZ6FH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Yd9y8TqJ
for(int i=0;i<nStartPos.length;i++) I#0$5a},u^
{ LY7'wONx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (_D#gr{S=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rTcH~s D`
nStartPos,nEndPos,i); 4r %NtXAa
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <D?`*#K
fileSplitterFetch.start(); uKplPze?
} )Fbkt(1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !.!Ervi!N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q[ IaA"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4GJsVA(d|
nEndPos = " + nFileLength); +'l@t bP
// fileSplitterFetch[nPos.length-1].start(); #qzozQ4
^K8Ey#T
.- w*&Hd7b
//等待子线程结束 p AD@oPC
//int count = 0; hP #>`)aNY
//是否结束while循环 dS-l2 $n
boolean breakWhile = false; 2Tp.S3
:`d& |BB
+=*ZH`qX
while(!bStop) 7yKadM~)
{ (RQ kwu/
write_nPos(); :Q89j4,
Utility.sleep(500); v6FYlKU@8
breakWhile = true; H}d&>!\}F
nI-\HAX
Gk<h_1WWK
for(int i=0;i<nStartPos.length;i++) >zhbOkR9c
{ tH$Z_(5
if(!fileSplitterFetch.bDownOver) 9G&l{7=
{ <)&;9C
breakWhile = false; <~]s+"oVc
break; 3]T2Zp&;
} m}k rG
} Rh%x5RFFc
if(breakWhile) *@dqAr%
break; t>^An:xT
C{4[7
WVKzh
//count++; Pr" 2d\
//if(count>4) ,+0_kndR
// siteStop(); dx|j,1e
} {'JoVJKv
0q81H./3
A^G%8 )\
System.err.println("文件下载结束！"); V^"5cW
} /Ue~W,|
catch(Exception e){e.printStackTrace ();} 2x0[@cTi?
} V5m4dQ>t
S?&ntUah
uSH.c>
//获得文件长度 (JOge~U
public long getFileSize() B#8!8
{ qWdL|8
int nFileLength = -1; mI-$4st]
try{ \qKh9
URL url = new URL(siteInfoBean.getSSiteURL()); @hp@*$#& 9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \G2&
httpConnection.setRequestProperty("User-Agent","NetFox"); ,_HVPE
.:E%cL +h
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int responseCode=httpConnection.getResponseCode(); yy@g=<okt\
if(responseCode>=400) I;9>$?t[
{ c<|;<8ew
processErrorCode(responseCode); ftRf~5d2
return -2; //-2 represent access is error dG\dGSZ\h
} "4Cb dD//
Y'wQ(6ok
yi PMJ
String sHeader; aVEg%8
;BsyN[bF
}Til $TT%H
for(int i=1;;i++) ZJ1%
{ ry0P\wY}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R]H/Jv\'
//Utility.log(in.readLine()); }9=VhC%J
sHeader=httpConnection.getHeaderFieldKey(i); Bg{"{poy
if(sHeader!=null) *Mk5*_
{ NvY%sx,
if(sHeader.equals("Content-Length")) mGb,oj7l
{ (V5_q,2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @uApm~}
break; 63 F@Ft
} Eu2@%2}P
} ;.+sz(:hm
else pKMy:j
break; P`0}( '"U
} @uXF(KDX
} >La!O~d
catch(IOException e){e.printStackTrace ();} 1?\G6T
catch(Exception e){e.printStackTrace ();} qXcHf6
Jsde+G,N
-pvF~P?8U
Utility.log(nFileLength); :+06M@
`ZhDoLpH<
hX;JMQ915
return nFileLength; e'Njl?>3
} 5o-WA1
`saDeur#X
D<%/:M
//保存下载信息（文件指针位置） >NDI<9<'0}
private void write_nPos() Gf*|f"O
{ hj[&.w
try{ u 6A!Sw
output = new DataOutputStream(new FileOutputStream(tmpFile)); Xy0*1$IS]
output.writeInt(nStartPos.length); SHWD@WLE4
for(int i=0;i<nStartPos.length;i++) g$+ $@~
{ j6}/pe*;;T
// output.writeLong(nPos); [TRHcz n
output.writeLong(fileSplitterFetch.nStartPos); |L wn<y
output.writeLong(fileSplitterFetch.nEndPos); ROb2g|YXG
} kyR=U`OW
output.close(); &V"9[0
} P3Ocfpf Bp
catch(IOException e){e.printStackTrace ();} ?QR13l(
catch(Exception e){e.printStackTrace ();} VEFUj&t;xW
} :Aq==N_/2
f_'#wc6
$^~dqmE2,
//读取保存的下载信息（文件指针位置） _!_%Afz
private void read_nPos() K FMx(fD
{ w\SfzJN
try{ x`9IQQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0q}k"(9
int nCount = input.readInt(); GE?M. '!{{
nStartPos = new long[nCount]; ^I!u H1G
nEndPos = new long[nCount]; 1!/WC.0
for(int i=0;i<nStartPos.length;i++) x:dI:G
{ n3x<L:)
nStartPos = input.readLong(); BeFCt;
nEndPos = input.readLong(); -aSj-
} n06T6oc
input.close(); P~xP@?I%
} uPh/u!
catch(IOException e){e.printStackTrace ();} 3FetyWl'
catch(Exception e){e.printStackTrace ();} pd%h5|*n;
} 'fo.1
):<9j"Z;At
{zhajY7
private void processErrorCode(int nErrorCode) r" 4u)H>
{ +t[i68,%
System.err.println("Error Code : " + nErrorCode); <gfkbDP2
} Lfr>y_i;F
i?^lEqy[
?OD43y1rzd
//停止文件下载 ^&8FwV]
public void siteStop() <e)u8+(
{ 7:Cq[u fl
bStop = true; 7j,u&%om
for(int i=0;i<nStartPos.length;i++) 7^bde<0
fileSplitterFetch.splitterStop(); J)I|Xot
(?y (0%q
lE|Hp
} 3]MSS\uB
} ']Z1nb
//负责部分文件的抓取 Cr&,*lUo
**FileSplitterFetch.java =pa F6!AB
*/ xryXO(
package NetFox; y*oH"]D
?hfyQhR
QP?eKW9 :
import java.io.*; ^s.necg0
import java.net.*; vXI2u;=y
pXap<T
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public class FileSplitterFetch extends Thread { 4;;K1< 1
P[q 'Y^\
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String sURL; //File URL =hAH6C
long nStartPos; //File Snippet Start Position fY|P+{BO2
long nEndPos; //File Snippet End Position ^E]Xq]vd"
int nThreadID; //Thread's ID e<Bwduy
boolean bDownOver = false; //Downing is over X<p'&
boolean bStop = false; //Stop identical x9Oo.[
FileAccessI fileAccessI = null; //File Access interface -mfdngp3
f?Am)
XSBh+)0Ww
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {BI5lvx:
{ F'Lav?^
this.sURL = sURL; yb4Jsk5%
this.nStartPos = nStart; LFwRTY,G
this.nEndPos = nEnd; | > t,1T.
nThreadID = id; ]:g;S,{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \A%s" O/
} 'O:QS)
W`k||U9
9$Dsm@tX
public void run() pVN) k
{ (U?*Z/
while(nStartPos < nEndPos && !bStop) wgPkSsuBuC
{ '.$va<
hO?RsYJ.F
f%gdFtJ &
try{ q'9}Hz
URL url = new URL(sURL); ] -}Zd\Rs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W|,Y*l
httpConnection.setRequestProperty("User-Agent","NetFox"); I 7 B$X=
String sProperty = "bytes="+nStartPos+"-"; ~E^lKe
httpConnection.setRequestProperty("RANGE",sProperty); Gm1[PAj
Utility.log(sProperty); P(|+1$#[
C]01(UoSZ
Pbo759q1
InputStream input = httpConnection.getInputStream(); m,|)$R
//logResponseHead(httpConnection); 0x1#^dII
jt6q8
#]vs*Sz
byte[] b = new byte[1024]; Ex`!C]sQ
int nRead; ]>_Ie?L)<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) S9VD/
{ lO+6|oF0
nStartPos += fileAccessI.write(b,0,nRead); &l-1.muQ
//if(nThreadID == 1) FG@ ')N!g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,z@"pI b
} 552yzn1
ipi^sCYp
_&U.DMt2 C
Utility.log("Thread " + nThreadID + " is over!"); +3wVcL
bDownOver = true; 6jaol'{SuH
//nPos = fileAccessI.write (b,0,nRead); j~;kh_
} bd& /B&a
catch(Exception e){e.printStackTrace ();} Xe. az
} xhTiOt6l
} >3SZD
W? SFtz
uKF)'gj
//打印回应的头信息 |f}1bJE+
public void logResponseHead(HttpURLConnection con) !kG2$/lR
{ $kD;*v=
for(int i=1;;i++) ?ypX``3#s7
{ 93]67PL#+
String header=con.getHeaderFieldKey(i); ]hHL[hoFC
if(header!=null) 9esMr0*=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); W!=X_
Utility.log(header+" : "+con.getHeaderField(header)); xZc].l6
else X8uAwHa6F
break; xa&5o`>1G
} PN"s^]4
} xC}9W6
l.3|0lopX)
IMT]!j&Y,
public void splitterStop() |08'd5
{ p~bx
bStop = true; fFiFS\''V
} ='z4bU
0*{2^\
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} o1^Rx5
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b>]MZhLJe
/* X={Z5Xxr"
**FileAccess.java w;=g$Bn
*//文件访问(定位，写) *%p`Jk-U
package NetFox; JQ"R%g`8
import java.io.*; g\~n5=-D
8nKb mjM
>\s8S}p
public class FileAccessI implements Serializable{ U9/6F8D1Y1
q:a-tdv2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d(!g9H
RandomAccessFile oSavedFile; !QXPn}q^0
long nPos; {I^@BW-
,B8u?{O
s+a} _a:
public FileAccessI() throws IOException 8{)j"rghah
{ l1#F1q`^t
this("",0); }T1.~E
} FA7q pc
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3<A$lG
public FileAccessI(String sName,long nPos) throws IOException qC4Q+"'
{ `-)Hot)
oSavedFile = new RandomAccessFile(sName,"rw"); 1n-+IR"
this.nPos = nPos; FofeQ
oSavedFile.seek(nPos); A(v5VvgZE
} {1Hs5bg@
Q xm:5P
)0UXTyw^
public synchronized int write(byte[] b,int nStart,int nLen) ~M Mv+d88
{ Wfp>BC
int n = -1; hcX`X2^
try{ )8@|+'q
oSavedFile.write(b,nStart,nLen); O+ghw1/
n = nLen; <4%cKW0
} ;,7/>Vt
catch(IOException e) al@Hr*'
{ 2Sb68hJIE
e.printStackTrace (); cD JeYduK
} `c.P`@KA
;t\oM7J|
Je &O
return n; #C#*yE
} h*B7UzCg
{"WfA
hRaX!QcG3
} D\0qlCAs
zbgH}6b
({!S!k
/* 1G`zwfmh~
**SiteInfoBean.java }[mLtv%&
*/ b2Oj 1dP1
package NetFox; Zp qb0ro
S17 c#6vT
z;Yo76P
public class SiteInfoBean { L{F[>^1Sb
pz0Q@n/X
peD7X:K\s
private String sSiteURL; //Site's URL ^SvGSxi
private String sFilePath; //Saved File's Path }O+`X) 9
private String sFileName; //Saved File's Name oa<%R8T?@
private int nSplitter; //Count of Splited Downloading File M"!{Dx~
F|bg2)|du8
.g?Ppma
public SiteInfoBean() ~v|NC([(
{//nSplitter的缺省值为5 -I'Jm=q3]
//default value of nSplitter is 5 )l6(ss!J
this("","","",5); W'! I+nh
} 35 d:r:
ArVW2gL
uWDWf5@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4`zK`bRcK#
{ PFI^+';
sSiteURL= sURL; &1Cif$Y4w
sFilePath = sPath; sDl@
sFileName = sName; 7?"-:q
this.nSplitter = nSpiltter; zJH:`~GxE
tb/`*Yl@
9(pF!}1%\
} }P\J?8
k, >*.Yoh
(MzThGJK_
public String getSSiteURL() 7!PU}[:
{ +. tcEbFL
return sSiteURL; oZ\zi> Y,
} ]Wg&r Y0
z*e`2n#\
,{Ga7rH*
public void setSSiteURL(String value) vWVQ8S.
{ +HkEbR'G0
sSiteURL = value; w[]\%`69}Z
} 7RCVqc"
4WXr~?Vq9
TR'<D9kn
public String getSFilePath() 5gKXe4}\/|
{ =z*SzG
return sFilePath; N~vK8j@
} OICH:(t_
MmH(dp+
Y$0K}`{
public void setSFilePath(String value) [oG Sy5bB
{ "?S>}G\
sFilePath = value; Rc(E';uc
} R/P9=yvg0
auHP^O>4L
0w!:YB,}
public String getSFileName() *0/%R{+S
{ YJB/*SV^
return sFileName; ge|Cvv
} rYO~/N
'k9Qd:a}
Z)!#+m83>-
public void setSFileName(String value) %TYe]^/'y
{ m2v'zJd}g
sFileName = value; 2Q)pT$
} ]zh6[0V7V
Yv"-_
/E^j}H{
public int getNSplitter() f{+X0Oj
{ tvOyT6]
return nSplitter; o+g\\5s
} iJb-F*_y
>2ny/AK|
O2S{*D={
public void setNSplitter(int nCount) (".WJXB\
{ 8V@\$4@b!#
nSplitter = nCount; C]M{
} [[uZCKi
} UUEbtZH;
j"9Zaq_
1O+$"5H
/* l 9bg
**Utility.java PBb'`PV
*/ \OVw
package NetFox; :~\ y<
p!7(ayu
S4D~`"4$/
public class Utility { 8X)1bNGqhe
,lQfsntk'
cB_3~=fV
public Utility() 9 =D13s(C
{ 9d8U@=
fKNDl\SD
N >k,"=N/
} MrhJk
Hh'o:j(^
//线程睡眠 vPM2cc/o
public static void sleep(int nSecond) -5Aqf\
{ +t}<e(
try{ @] 3`S
Thread.sleep(nSecond); LX7<+`aa
} [='<K
catch(Exception e) F32U;fp3
{ 0pA>w8mh
e.printStackTrace (); B+lnxr0t
} aj}#~v1
} hD,@>ky
VL2ACv(
//日志 UQ~gjnb[c
public static void log(String sMsg) 3$PGLM
{ pXf5/u8&
System.err.println(sMsg); |3=tF"h
} :s#&nY
YQaL)t$0
%kL]-Z
public static void log(int sMsg) 9`G}GU]@}
{ !uN_<!
System.err.println(sMsg); FmhN*ZXr#
} z6'l" D'h
} :PP!v!vk
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;k8U5=6a
/* fX}dQN~z
**TestMethod.java !==C@cH<N
*/ 5mg] su&#
package NetFox; c{!XDiT]P
vf?m-wh
XT\Q"=FD
public class TestMethod { \"l/D?+Q
L lVE5f?
/igbn
public TestMethod() A#CGD0T
{ ///xx/weblogic60b2_win.exe xcC^9BAj
try{ 7jYW3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :+UahwiRD"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dgW/5g
SiteFileFetch fileFetch = new SiteFileFetch(bean); kx07Ium
fileFetch.start(); #RP7?yGM,
} Df0m
catch(Exception e){e.printStackTrace ();} yYvv!w+@Q
PZhpp"
bf$4Z: Y
} fe7DS)U
zwdi$rM5
Q9sxI}D )R
public static void main(String[] args) \O+Hmi^
{ ux1SQ8C*
new TestMethod(); OB\jq!"
} JV;-P=o1B
} HKYJgx
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