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)ibDrX!I
} l4^8$@;s
for(int i=0;i<nEndPos.length-1;i++) SYOU&*
{ Qbj:^{`>(
nEndPos = nStartPos[i+1]; WN#dR~>
} ZQJh5.B
nEndPos[nEndPos.length-1] = nFileLength; y2C/DyuAY|
} {\=NZ\
} %cMayCaI!@
g{7?#.7
y|.dM.9V
//启动子线程 KEr?&e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Od]wh
for(int i=0;i<nStartPos.length;i++) stCFLYox
{ dnX^?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IG@@CH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4_Rv}Yd
nStartPos,nEndPos,i); j)O8&[y=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yj`xOncE}
fileSplitterFetch.start(); R2[ }
} "6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1]jUiX=T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^m^,:]I0P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M Xl!
nEndPos = " + nFileLength); &[}5yos r
// fileSplitterFetch[nPos.length-1].start(); 7)3cq}]O
SB!m&;Tb
ok9G9|HA
//等待子线程结束 9\NP)Vm$^
//int count = 0; < 'qtqUL\
//是否结束while循环 l'Z `%}R
boolean breakWhile = false; DWJkN4}o
}A_>J7w
t~]oJ5%
while(!bStop) GEf[k OQ
{ |=}v^o ZC
write_nPos(); }=."X8zOI8
Utility.sleep(500); !' @
breakWhile = true; r;aP`MVO<
gIXc-=Ut
_N`pwxpsb
for(int i=0;i<nStartPos.length;i++) [ w1"
{ /T2f~1R
if(!fileSplitterFetch.bDownOver) 1]XIF?_Dm
{ TMQu'<?V
breakWhile = false; U^X8{,8O
break; ud.Bzg:/
} ? &;d)TQ
} OKq={l
if(breakWhile) KbV%8nx!!
break; OECXNx
%4E7 Tu,1
IN9o$CZ:
//count++; 8M'6Kcr
//if(count>4) #[#dc]D
// siteStop(); "ae55ft//
} Uyyw'Ni
!P26$US%P
R OQIw
System.err.println("文件下载结束！"); a?!Joi[
} ,/>~J]:\;
catch(Exception e){e.printStackTrace ();} W\<5'9LNb
} {N,w5!cP
[%8+Fa~Wa
5OUe|mS
//获得文件长度 |KC3^
public long getFileSize() !f\6=Z?>3
{ w65 $ R
int nFileLength = -1; w,.Hdd6
try{ GS3ydN<v
URL url = new URL(siteInfoBean.getSSiteURL()); O_PC/=m1@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XfT6,h7vFL
httpConnection.setRequestProperty("User-Agent","NetFox"); {:enoV"
!<2*B^
M$gy J!Pb
int responseCode=httpConnection.getResponseCode(); }q ?iJ?P
if(responseCode>=400) \rf1#Em
{ GOwd=]e
processErrorCode(responseCode); [P{Xg:0
return -2; //-2 represent access is error 3r{'@Y =)Y
} ()>\D
%]Nz54!
3)g1e=\i$
String sHeader; Aq|LeH
^HL#)fK2I
~ab"q%
for(int i=1;;i++) ]3QQ"HLcp
{ 95wV+ q*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z9aDE@A
//Utility.log(in.readLine()); =8dCk\/
sHeader=httpConnection.getHeaderFieldKey(i); D#m+w
if(sHeader!=null) a4: PufS
{ "rjJ"u1
if(sHeader.equals("Content-Length")) y_QxJ~6t
{ ak;Z;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I( y Wct
break; 6U+#ADo
} y~S[0]y>
} xSOL4
else ^LC5orO
break; U0N[~yW(t1
} BW\R
} LbYI{|_Js
catch(IOException e){e.printStackTrace ();} WD?V1:>+
catch(Exception e){e.printStackTrace ();} &GD7ldck
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mc$c!Ax*
Utility.log(nFileLength); [7s5Vt|
!J6s^um
)v-* WreS
return nFileLength; (wY%$kW4
} tt[_+e\4
~IWi@m{
/w!' [
//保存下载信息（文件指针位置） ~V|!\CB
private void write_nPos() wRiP5U,
{ +`4}bc,G
try{ r?+u}uH
output = new DataOutputStream(new FileOutputStream(tmpFile)); J/=A f [
output.writeInt(nStartPos.length); n `Xz<Q!
for(int i=0;i<nStartPos.length;i++) */+s^{W7
{ RU>vnDaC
// output.writeLong(nPos); q,(&2./
output.writeLong(fileSplitterFetch.nStartPos); QNtr=
output.writeLong(fileSplitterFetch.nEndPos); N7jRdT2k%
} %8{_;-f
output.close(); mcXakWmi
} '_&(Iwu
catch(IOException e){e.printStackTrace ();} RtW5U8
catch(Exception e){e.printStackTrace ();} GSFT(XX
} LK%B6-;~-
:hr@>Y~r
gdZVc9_
//读取保存的下载信息（文件指针位置） z0UO<Y?9
private void read_nPos() [uY2Nh
{ ).boe& .
try{ C/vLEpP{(/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ["IJh
int nCount = input.readInt(); g|HrhUT;
nStartPos = new long[nCount]; .#eXNyCe
nEndPos = new long[nCount]; 1G;Ns] u
for(int i=0;i<nStartPos.length;i++) &zd7t6
{ $"(YE #]|
nStartPos = input.readLong(); H44&u](8{
nEndPos = input.readLong(); D6oby*_w
} Om"3Q/&
input.close(); &aQ)x
} c+{4C3z
catch(IOException e){e.printStackTrace ();} DQICD.X6R
catch(Exception e){e.printStackTrace ();} zLqp@\sT
} >z -(4Z
oMe]dK
4<K`yU]"
private void processErrorCode(int nErrorCode) T6r~OV5
{ bx^EaXj(r
System.err.println("Error Code : " + nErrorCode); gWo~o]f
} NKKOA
sZB6zTX J
kf!/9
//停止文件下载 7qz-RF#s8
public void siteStop() EXcjF
{ z\Y^x9
bStop = true; E<SEFn
for(int i=0;i<nStartPos.length;i++) IR8&4qOs
fileSplitterFetch.splitterStop(); ^ks^9*'|j
!q\w"p0X
,b(S=r
} PcHFj+:
} I{I [N &N
//负责部分文件的抓取 @e0skc
**FileSplitterFetch.java \=V[ba:q
*/ %pkq ?9
package NetFox; hb8XBBKR
PEt8,,x<"
da'E"HN@G~
import java.io.*; AJd.K'=8
import java.net.*; U(=9&c@]
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l1Q+hz5"*U
public class FileSplitterFetch extends Thread { PB67?d~
6CmFmc,
,HkhKbQ
String sURL; //File URL e=UVsYNx
long nStartPos; //File Snippet Start Position cu?(P;mQi
long nEndPos; //File Snippet End Position 0P40K
int nThreadID; //Thread's ID )9*3^v
boolean bDownOver = false; //Downing is over r{R7"
boolean bStop = false; //Stop identical Zt2@?w;
FileAccessI fileAccessI = null; //File Access interface ]</4#?_
7jH`_58
WTYFtZD[yH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m{.M,Lm:
{ kz;_f
this.sURL = sURL; 51 +M_~
this.nStartPos = nStart; 9r+O!kF(
this.nEndPos = nEnd; UZ\*]mxT
nThreadID = id; y*b.eO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5 t`ap
} .7gE^
r82o[+$u0K
lJzy)ne
public void run() _d| 62VS
{ jc.JX_/
while(nStartPos < nEndPos && !bStop) Ji:iKkI
{ l5Wa'~0qA
:sVHY2x
iQ{&&>V%
try{ +'qX sfc
URL url = new URL(sURL); W_,;eyo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 51M^yG&M
httpConnection.setRequestProperty("User-Agent","NetFox"); OW^2S_H5
String sProperty = "bytes="+nStartPos+"-"; )ozcr^
httpConnection.setRequestProperty("RANGE",sProperty); ? TT8|Os
Utility.log(sProperty); +e8>?dkq
#>:(#^Uu
CFJjh^ ~=
InputStream input = httpConnection.getInputStream(); \;*}zX
//logResponseHead(httpConnection); oCKM5AVWsv
uB<F.!3
|[37:m
byte[] b = new byte[1024]; OOBcJC
int nRead; -[pCP_`)u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rFq@]t3q
{ Y <Znv%M
nStartPos += fileAccessI.write(b,0,nRead); )jk1S
//if(nThreadID == 1) u.kYp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .i+* #djx
} pH\^1xj =
WR a+zii,
mUt,Z^ l`
Utility.log("Thread " + nThreadID + " is over!"); fNqmTRu
bDownOver = true; \POnsM)+l
//nPos = fileAccessI.write (b,0,nRead); v<%kd[N
} wt}%2x} x
catch(Exception e){e.printStackTrace ();} l7'{OB L
} v:"m
} ~n/Aq*
3Rd`Ysp
?]W~ qgA
//打印回应的头信息 ;wbUk5Tf/
public void logResponseHead(HttpURLConnection con) #H;hRl
{ 7V}]C>G
for(int i=1;;i++) kG$E tE#
{ w#xeua|*I#
String header=con.getHeaderFieldKey(i); B [+(r
if(header!=null) 7?MB8tJ5r4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m4"N+_j
Utility.log(header+" : "+con.getHeaderField(header)); feI./E
else ;+i'0$;*w
break; d@4rD}_Z
} xJ~ gT
} hV-VeKjZ(
i,#k}CNu
"!%wh6`>Md
public void splitterStop() b " ")BT
{ #v4LoNm
bStop = true; zLsb`)!
} E.J0fwyT
X*!Dc,0.k
dn ZzA
} %kh#{*q$
]cm6 |`pz
u^Nxvx3l0
/* g@~!kh,TH
**FileAccess.java ]*N:;J
*//文件访问(定位，写) 7}4'dW.
package NetFox; 5@`F.F>"
import java.io.*; ?;|@T ty%
e}42/>}#D
Wy<[(Pd
public class FileAccessI implements Serializable{ q,B3ru.?d
i;o}o*=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :O $@shV
RandomAccessFile oSavedFile; mZ~qG5@/F
long nPos; 7}be>(
7J9l.cM3
-2F@~m|
public FileAccessI() throws IOException |3}5:k
{ 4YszVT-MU~
this("",0); 6M ^IwE
} VeZey)Q
n*Q`g@`
cjuZBFl
public FileAccessI(String sName,long nPos) throws IOException q|5Q?t:,r
{ ZJ;LD*
oSavedFile = new RandomAccessFile(sName,"rw"); RMoJz6^>
this.nPos = nPos; lT.zNhz:d9
oSavedFile.seek(nPos); i+f7
} |6E .M1
CRFCqmevR
)kYOHS
public synchronized int write(byte[] b,int nStart,int nLen) 3{"byfO#%
{ ! ja[4.
int n = -1; _%Bz,C8
try{ Sw)i1S9
oSavedFile.write(b,nStart,nLen); u~W{RHClW
n = nLen; -hWC_X:9jP
} BQ#3QL't
catch(IOException e) rH&G<o&,
{ <I;5wv
e.printStackTrace (); #~^btL'dHF
} @F>F#-2
YOyp|%!
|; $Bb866/
return n; fXO_g
} z8HsYf(!
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!VwmPAMr#v
} m9$a"$c
d?A}qA[(
uWjN2#&,
/* k[\a)WcY8
**SiteInfoBean.java M;+IZr Wkl
*/ ?}}qu'N:N
package NetFox; W|MWXs5'1*
%r%So_^
.2.qR,"j
public class SiteInfoBean { dC.bt|#Oz
@w\I qr
$ rUSKm#
private String sSiteURL; //Site's URL 2Il8f
private String sFilePath; //Saved File's Path kA4@`YCl
private String sFileName; //Saved File's Name K R,z^9
private int nSplitter; //Count of Splited Downloading File c 6"Ib)
}#1/fok
,:)`+v<
public SiteInfoBean() bFY~oa%C
{//nSplitter的缺省值为5 Ipe n
//default value of nSplitter is 5 Ooc\1lX
this("","","",5); ve Tx, \6@
} R_ ZK0ar
fE]XWA4U
LlHa5]E@6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +D&Pp0xe
{ o(!@7Lqq
sSiteURL= sURL; k()$:-V
sFilePath = sPath; k7@t{Cu0D&
sFileName = sName; Dnw|%6Y
this.nSplitter = nSpiltter; pTJX""C
w_hHfZ9E
*bd[S0l
} X6\ sF"E
oDn|2Sdqd
Qkcjr]#^$
public String getSSiteURL() j$Ab>}g]
{ 0.TaXbi
return sSiteURL; k&/OU:7Y
} - +>1r
+s++7<C
E&`Nh5JfC
public void setSSiteURL(String value) x79Ha,
{ `=UWqb(K_
sSiteURL = value; I_1e?\
} i,IB!x
b2,!g }I
Djq!P
public String getSFilePath() q_kdCO{:df
{ #bX9Tu0
return sFilePath; T4)fOu3]
} ,<-G<${
C;+h.;}<D
(o5j'2:.
public void setSFilePath(String value) w[tmCn+
{ iOAbaPN
sFilePath = value; nKa$1RMO
} i|`dWOVb
Zf$Np50@(
#>lG7Ns|4
public String getSFileName() [NMVoBvG
{ PHOP%hI$
return sFileName; B"yFS7Rrj
} 5GA C`}}
eET&pP3Rp
U_x)#,4
public void setSFileName(String value) k:jSbbQ
{ @,Gxk
sFileName = value; 1 zw*/dp
} f+8wl!M+6
X+UJzR90
#(An6itl
public int getNSplitter() ^8.]d~j
{ /xtq_*I1S
return nSplitter; q$I:`&
} _SW3_8SuM.
/1Ue?)g
Cj~'Lhmv'T
public void setNSplitter(int nCount) zR2B- &]H
{ .o) `m9/
nSplitter = nCount; QQWadVQo
} :VTTh |E%#
} eek7=Z
'yMF~r3J
d3=KTTi\
/* <HbcNE~
**Utility.java CrwwU7qKL
*/ ?@E!u|]K
package NetFox; g$b<1:8
j4qJ.i
|JQQU!x
public class Utility { Q~Hy%M%R3
Y1]n^
C=eF.FB;'
public Utility() V4_=<W
{ |`.([2
)jt #=9ZQ
4O35"1
} rx] @A
.ev?"!Vpp9
//线程睡眠 gP;&e:/3
public static void sleep(int nSecond) r-Pkfy(
{ YJ\Xj56gv
try{ \--8lH -K
Thread.sleep(nSecond); 'IwNTM
} s,]z[qB#$
catch(Exception e) {GQ^fu;q
{ b45-:mi!&#
e.printStackTrace (); ,^2>k3=
} ,%M$0poKM
} JU)dr4S?
R^Y <RI
//日志 |'B7v i)
public static void log(String sMsg) Z'.AAOG
{ njputEGX
System.err.println(sMsg); fTK3,s1=
} 2Eu`u!jhx
Jcrw#l8|C
Zg{KFM%
public static void log(int sMsg) Pu"P9
{ toBHkiuD
System.err.println(sMsg); NgP&.39U
} ~v|>xqWV
} %5"9</a&G
8~@c)Z;
Yp^rR }N
/* kY-N>E:
**TestMethod.java RwpdRBb
*/ paCV!tP
package NetFox; 4\8+9b\9"
H[U!%Z
e?8FN. q
public class TestMethod { ] Zy5%gI
hG12ZZD
3sy (vC
public TestMethod() #Y a4ps_
{ ///xx/weblogic60b2_win.exe @1o/0y"
try{ #W4dkCd(pF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F%@aB<Nu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'h|DO/X~L
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3q\,$*D.
fileFetch.start(); o$jLzE"
} Y)*#)f
catch(Exception e){e.printStackTrace ();} vqDu(6!2
keL&b/@
&8Cu#^3
} 1WxK#c-)
OEA&~4&{7
jFL #s&ft
public static void main(String[] args) X86O lP)eX
{ n|Q@UPb/=
new TestMethod(); 'YmIKIw
} 3no%E03p
} s>7}zU]
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