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)); io r [v
} :e<`U~8m
for(int i=0;i<nEndPos.length-1;i++) syW9Hlm
{ Ie&b<k
nEndPos = nStartPos[i+1]; J6( RlHS;
} @Gn?8Ur%
nEndPos[nEndPos.length-1] = nFileLength; jo;uRl
} m$E^u[
} )y/DGSd
/q"d`!h)w
<[y$D=n
//启动子线程 zdjM%l);
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q),3&4pM
for(int i=0;i<nStartPos.length;i++) JXLWRe
{ Y!= k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1ntkM?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Vy% :\p+
nStartPos,nEndPos,i); aq0iNbv@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b%[nB
fileSplitterFetch.start(); 7edPH3
} \>Ga-gv6/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (,Ja
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]/o12pI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T}tE/
nEndPos = " + nFileLength); KZrMf77=
// fileSplitterFetch[nPos.length-1].start(); oEQ{m5O9
i+)}aA
(zs4#ja2,
//等待子线程结束 p2Dh3)&
//int count = 0; YA"Ti9-EV
//是否结束while循环 +^4BO`
boolean breakWhile = false; b.R!2]T]i^
*gd?>P7\0
{K45~ha9!m
while(!bStop) n^iNo
{ M[YTk=IM#
write_nPos(); Q%& _On
Utility.sleep(500); /ojO>Y[<
breakWhile = true; '?"t<$b
1p7cv~#95
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for(int i=0;i<nStartPos.length;i++) ]6t]m2~\
{ n#+%!HTh
if(!fileSplitterFetch.bDownOver) 'yPCZ`5H(
{ <+AIt
breakWhile = false; .M9d*qp`S
break; Pz]bZPHn
} Hp)X^O"
} w]>"'o{{
if(breakWhile) 4M @oj
break; -}{%Q?rYj
,vPe}OKj
=\~E n5
//count++; r]A"Og_U
//if(count>4) ~ X-)_zH
// siteStop(); ;^R A!Nj
} aO8ch
x9&-(kBU
:tRf@bD#
System.err.println("文件下载结束！"); 4. 1rJa
} r<;l{7lY_
catch(Exception e){e.printStackTrace ();} slU
} }JRP,YNh
m7$8k@r
Jy \2I{I'
//获得文件长度 iO!27y
public long getFileSize() Ho3dsh)
{ iM:yX=>a
int nFileLength = -1; CF]i}xpWV
try{ kf<c,3A
URL url = new URL(siteInfoBean.getSSiteURL()); Lltc4Mzw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A0G)imsW:_
httpConnection.setRequestProperty("User-Agent","NetFox"); YiD-F7hf.*
(2UW_l
?2{bKIV_
int responseCode=httpConnection.getResponseCode(); !7}IqSs
if(responseCode>=400) 'eDJ@4Xm
{ _eGT2,D5r
processErrorCode(responseCode); $:Rn;
return -2; //-2 represent access is error 2ck4C/ h
} BR+nL6sU
(=1)y'.
))!Bg?t-
String sHeader; {J (R
[`d$X^<y;
O7%2v@j|8
for(int i=1;;i++) -K"4rz
{ P` #QGZ>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gw"~RV0
//Utility.log(in.readLine()); dm6~
sHeader=httpConnection.getHeaderFieldKey(i); - ay5
if(sHeader!=null) S=' wJ@?;
{ *I0Tbc O
if(sHeader.equals("Content-Length")) d{f@K71*
{ U[R@x`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \i!Son.<
break; 6R`Oh uN.>
} f/,tgA
} tAjx\7IX
else 4[TR0bM%
break; D==Mb~
} SVagT'BB
} IS BV%^la|
catch(IOException e){e.printStackTrace ();} w1r$='*I
catch(Exception e){e.printStackTrace ();} YzAFC11,
XF|WCZUnY%
q_ %cbAcD
Utility.log(nFileLength); \?DR s
f6!D L<
*XbI#L%>
return nFileLength; =oX>Ph+ P
} 'xnnLCm.
\hlR]m!C
n,j$D62[
//保存下载信息（文件指针位置） 3xNMPm
private void write_nPos() |%1?3Mpn
{ 1tB[_$s
try{ <*|?x86~
output = new DataOutputStream(new FileOutputStream(tmpFile)); -kpswP
output.writeInt(nStartPos.length); fQ 7vL~E
for(int i=0;i<nStartPos.length;i++) @*MC/fe
{ ~GJN@ka4%
// output.writeLong(nPos); |.P/:e9
output.writeLong(fileSplitterFetch.nStartPos); Fl3#D7K
output.writeLong(fileSplitterFetch.nEndPos); WKmbNvN^
} K>2#UzW
output.close(); AW,OHSXh6
} K-eY|n
catch(IOException e){e.printStackTrace ();} w!SkWS b,~
catch(Exception e){e.printStackTrace ();} J:j<"uPm
} 4v'A\~ZU
M2@b1;
9bJQT'<R
//读取保存的下载信息（文件指针位置） (\a6H2z8l
private void read_nPos() tNIlzR-
{ s%pfkoOY%
try{ ] asBd"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dQb.BOI)h
int nCount = input.readInt(); 1tMQqI`N
nStartPos = new long[nCount]; !k&Q 5s:
nEndPos = new long[nCount]; @}s$]i$|-
for(int i=0;i<nStartPos.length;i++) 6rN(_Oi-
{ B[5r|d'
nStartPos = input.readLong(); xJZ@DR,#
nEndPos = input.readLong(); X|DO~{-au
} ;WU<CKYG*
input.close(); >dzsQ^Nj
} E7zm{BX]
catch(IOException e){e.printStackTrace ();} Bi3+)k>u7
catch(Exception e){e.printStackTrace ();} Pw0Ci
} x3pND
aqU' T
|=a}iU8
private void processErrorCode(int nErrorCode) J#2!ZQE 3
{ ? 1*m,;Z
System.err.println("Error Code : " + nErrorCode); :-`7Q\c}
} r\`+R"
Jb["4X;h
<?Wti_ /M
//停止文件下载 o*g|m.SjL
public void siteStop() $2~\eG=u H
{ vhuw&.\
bStop = true; ULH0'@BJ
for(int i=0;i<nStartPos.length;i++) TBrGA E
fileSplitterFetch.splitterStop(); }MbH3ufC
Q,h7Sk*
C1EtoOv K
} %wptZ"2M
} JRMM?y
//负责部分文件的抓取 Wu6<\^A
**FileSplitterFetch.java A'&n5)tb
*/ Mwp$
package NetFox; 4*.K'(S5fx
3jH\yXj
k n[Y
import java.io.*; ;a{:%t
import java.net.*; WY:&ugGx
llV3ka^!
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public class FileSplitterFetch extends Thread { G~7 i@Zs
J[~5U~F
<"D=6jqZ
String sURL; //File URL P^`duZ{T
long nStartPos; //File Snippet Start Position -u!FOD/
long nEndPos; //File Snippet End Position `1OgYs
int nThreadID; //Thread's ID 2lKV#9"
boolean bDownOver = false; //Downing is over A5'NGt
boolean bStop = false; //Stop identical r7]zQIE
FileAccessI fileAccessI = null; //File Access interface c#IYFTz
b1XRC`Gy
r|e-<t4.9L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D]a<4a18
{ !\8 ;d8
this.sURL = sURL; VQ5nq'{v
this.nStartPos = nStart; D?yG+%&9
this.nEndPos = nEnd; %ek'~
nThreadID = id; z@Q@^ &0Mr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NLPkh,T:
} Uo12gIX
65h @}9,U
+Q=1AXe
public void run() ]ul$*
{ `@[c8j7
while(nStartPos < nEndPos && !bStop) h_1T,f(
{ gBh;=vOD
Ghl'nqPlm
AcI,N~~
try{ :l7U>~ o
URL url = new URL(sURL); VhjM>(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~_s?k3cd
httpConnection.setRequestProperty("User-Agent","NetFox"); 8d*/HF)h
String sProperty = "bytes="+nStartPos+"-"; [gy*`@w
httpConnection.setRequestProperty("RANGE",sProperty); P0H6mn*
Utility.log(sProperty); "YdEE\
>9RD_QG7
;S0Kh"A
InputStream input = httpConnection.getInputStream(); [V'QrcCF
//logResponseHead(httpConnection); 8Og_W8
Xc"&0v%;#
322jR4QGr
byte[] b = new byte[1024]; B+^(ktZp@
int nRead; JpsPNa
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \#o2\!@`
{ Mu'8;9_6
nStartPos += fileAccessI.write(b,0,nRead); (b'B%rFO
//if(nThreadID == 1) VJ ^dY;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mUS_(0q
} "qc6=:y}
8-y{a.,u.
={LMdC~5X
Utility.log("Thread " + nThreadID + " is over!"); >.dWjb6t
bDownOver = true; ^c:Fy+fb
//nPos = fileAccessI.write (b,0,nRead); K\XH4kic
} }y9mNT
catch(Exception e){e.printStackTrace ();} #2r}?hP/m
} kP/M<X"
} aK`@6F,]j
ui(^k $
%tG*C,l]
//打印回应的头信息 ^v.,y3
public void logResponseHead(HttpURLConnection con) .U T@p
{ J'N!Omz
for(int i=1;;i++) +cD!1IT:
{ j"AU z)x
String header=con.getHeaderFieldKey(i); J|&JD?
if(header!=null) !"8fdSfg w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wdUBg*X8
Utility.log(header+" : "+con.getHeaderField(header)); l}$ U])an#
else 2tal
break; lFTF ,G
} 5|jw^s7
} 0P\$2lk
6252N]*
TDd{.8qf
public void splitterStop() rj6#1kt
{ 2Ry1b+\
bStop = true; H,N)4;F<c
} kWdi595
NJNJjdD>
SJIOI@\b
} JPGzrEaZ
Q>n|^y6
Qx[t/~
/* %;.;>Y(-
**FileAccess.java P;k0W>~k
*//文件访问(定位，写) yRo-EP
package NetFox; QR1{ w'c
import java.io.*; {J^lX/D
wC5ee:u C%
C`5
public class FileAccessI implements Serializable{ ?(R]9.5S
cK 06]-Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .l@xsJn
RandomAccessFile oSavedFile; ^a#X9
long nPos; Uh][@35 p
;pnD0bH
[H=)
public FileAccessI() throws IOException S{Er?0wm.R
{ o`Ta("9^
this("",0); &LbJT$}V
} %Qj;,#z
)KP5WudX
4fe7U=#;Y
public FileAccessI(String sName,long nPos) throws IOException p1vp8p
{ gCxAG
oSavedFile = new RandomAccessFile(sName,"rw"); |O"lNUW
this.nPos = nPos; 1bH;!J
oSavedFile.seek(nPos); p ZZc:\fJ
} s M+WkN}{
a<@N-Exr
{c (!;U
public synchronized int write(byte[] b,int nStart,int nLen) uV=Qp1~
{ NOp609\^
int n = -1; FXs*vg`
try{ 7PkJ-JBA
oSavedFile.write(b,nStart,nLen); 0@EwM
n = nLen; &o<F7U'R
} kV38`s>+
catch(IOException e) 3YZs+d.;ib
{ Yh>]-SCw
e.printStackTrace (); IV)<5'v
} K3=3~uY
Jej` ;I
ldp%{"ZZ
return n; t 89!Ihk
} DoeiW=
Jm42b4
0A( +ZMd
} u{*SX k
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mL4]l(U
/* J2^'Xj_V
**SiteInfoBean.java xl#LrvxI
*/ }oNhl^JC
package NetFox; f{FDuIln
ObiT-D?)g
g]c6&Y,#
public class SiteInfoBean { {\(L%\sV@
]GRWnif
EbdfV-E
private String sSiteURL; //Site's URL TsGE cxIg
private String sFilePath; //Saved File's Path }6@pJG
private String sFileName; //Saved File's Name $k2*[sn,
private int nSplitter; //Count of Splited Downloading File tuhA 9}E
M`l.t -ut
*q1%IJ
public SiteInfoBean() ;dzL}@we
{//nSplitter的缺省值为5 /jRRf"B
//default value of nSplitter is 5 kbMYMx.[
this("","","",5); Oj^,m.R
} Q_Gi]M9
r3\cp0P;s
DuOG {
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )'4k|@8|
{ #/Eb*2C`b
sSiteURL= sURL; W]5USFan
sFilePath = sPath; P<f5*L#HD
sFileName = sName; 6C+"`(u%V
this.nSplitter = nSpiltter; )lZp9O
dx+hhg\L
$]/Zxd
} jb^N|zb
oDU ;E
g2T -TG'd
public String getSSiteURL() [!U?}1YQ
{ .;*s`t
return sSiteURL; )kkhJI*v
} R@`y>XGNJ
.Fa4shNV
f?'JAC*
public void setSSiteURL(String value) %,k][V
{ ^)W[l!!<)
sSiteURL = value; ()3O=!
} iX4Iu3
z~>pVs
|K|h+fgG6*
public String getSFilePath() g'|MA~4yB
{ 3dRr/Ilc
return sFilePath; gw}Mw
} T.qNCJmB
d:i;z9b@to
MKWyP+6`
public void setSFilePath(String value) [/BE8]M~
{ Y>&Ew*Y
sFilePath = value; `8Lo{P
} W<E47
\R3H+W
V@\%)J'g
public String getSFileName() E_bO9nRHV
{ +fnK/%b
return sFileName; V.{H9n]IO
} ;jipe3LU
P';?YV0
xu'yVt9RC
public void setSFileName(String value) R%c SJ8O#
{ -^ C=]Medl
sFileName = value; g{P%s'%*
} FSRj4e1y1
G2^et$<{uU
@S7sr-
public int getNSplitter() NMi45y(Y
{ bcZf>:gVf
return nSplitter; jr`Ess
} wX*K]VMn
:,DM*zBVp
Q pmsOp|
public void setNSplitter(int nCount) E=#0I]v[
{ %bdjBa}
nSplitter = nCount; "1-}A(X
} _IdRF5<4
} zH*KYB
fks)+L'
bN3#{l-`
/* vC5n[0
**Utility.java i}~SDY
*/ nYJTKU
package NetFox; l#}.^71+
SC- $B
UDL RCS8i
public class Utility { fhCc! \
KW7UUXL
P06RJE
public Utility() ?]4>rl}
{ "XT"|KF|D
1\r|g2Z :
9Fr3pRIJ
} >X51$wBL
%b^OeWip
//线程睡眠 MW+b;0U`#
public static void sleep(int nSecond) A3ZY~s#Iv
{ YQS5P#
try{ i>joT><B
Thread.sleep(nSecond); z-c}NdW
} RAp=s
catch(Exception e) /P 2[:[w
{ )<xypDQ
e.printStackTrace (); a:_I
} M5trNSL&u
} Tdc3_<1
^7.h%lSg
//日志 \fjMc }'
public static void log(String sMsg) dqX;#H}h
{ X~xd/M=9^
System.err.println(sMsg); Jx=hJ-FY
} 2mq$H_
AZ{^o4<q
#"49fMi/
public static void log(int sMsg) 1U,1)<z~u
{ 8L1ohj
System.err.println(sMsg); 9Mgq1Z
} d|iy#hy"_
} Q*XE h
${8?N:>t
bTSL<"(]N
/* L.=w?%:H=
**TestMethod.java wlPx,UqZ
*/ |0,vQv
package NetFox; dHk{.n^p
v-! u\
c c
public class TestMethod { =-o'gL
Ea(,aVlj
@K:N,@yq
public TestMethod() 1>Q'R
{ ///xx/weblogic60b2_win.exe <vUVP\u~$
try{ lW 81q2n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :ah 5`nmPO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [Ym
SiteFileFetch fileFetch = new SiteFileFetch(bean); Rl6\#C*
fileFetch.start(); P6Mhbmt9*
} 7FF-*2@
catch(Exception e){e.printStackTrace ();} _qWliw:0#
Gc$gJnQio
WX4;l(PL=
} y4Er@8I`
vsj3
RJeSi`19T)
public static void main(String[] args) T,_(?YJW
{ /(8a~f&%r
new TestMethod(); Krs2Gre}
} Y+qQIMZ
} tW;:-
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