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)); sfr(/mp(
} h0?2j)X_
for(int i=0;i<nEndPos.length-1;i++) p <eC<dtu
{ c[}(OH
nEndPos = nStartPos[i+1]; Md)zEj`\
} 1%M&CX
nEndPos[nEndPos.length-1] = nFileLength; "+KJop
} Lf:uNl*D
} d;Hn#2C
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9 7%0;a8
//启动子线程 UE _fpq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =k}SD96
for(int i=0;i<nStartPos.length;i++) 9[v1h,L
{ G{aT2c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6,1b=2G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @L84>3O
nStartPos,nEndPos,i); vgn@d,v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N-lGa@ j
fileSplitterFetch.start(); 71#I5*8
} 8,?v?uE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3qHQX?a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e]ig!G]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GwsY-jf
nEndPos = " + nFileLength); qP!eJ6[Nh"
// fileSplitterFetch[nPos.length-1].start(); f0+2t.tj
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!.7udYmB
//等待子线程结束 5q{h 2).)
//int count = 0; ufa41$B'yG
//是否结束while循环 ZA~Z1Mro#"
boolean breakWhile = false; d "BW/%m|g
d {lP
va/m~k|i
while(!bStop) Z>F^C}8f
{ puSLqouTM
write_nPos(); t<uYM
Utility.sleep(500); x+? 9C
breakWhile = true; l>lW]W
K.tlo^#^B[
K*K1(_x=
for(int i=0;i<nStartPos.length;i++) G DSfT{kK\
{ wYeB)1.
if(!fileSplitterFetch.bDownOver) G@!z$
{ Y izE5[*
breakWhile = false; q^8EOAvnZ
break; 7>o.0
} )j6eE+gF
} rgIrr5
if(breakWhile) 0m[dP
break; fi PIAT}
[{[N(g&d
:(3|HTz
//count++; UIJx*
//if(count>4) 5FvOznK^e
// siteStop(); Mro4`GL
} ;SwC&.I
r'/;O
@b&84Gn2 r
System.err.println("文件下载结束！"); ,reJ(s
} v|Jlf$>
catch(Exception e){e.printStackTrace ();} `Y?t@dd
} Rz%e>)
9V1cdb~?"T
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//获得文件长度 Ob+9W
public long getFileSize() }m]q}r
{ jX=lAs~6
int nFileLength = -1; huFz97?y(
try{ yT /EHmJ
URL url = new URL(siteInfoBean.getSSiteURL()); W-2i+g)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,1n >U?5
httpConnection.setRequestProperty("User-Agent","NetFox"); 1V&PtI3!!
u.|~
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int responseCode=httpConnection.getResponseCode(); *}b]rjsj
if(responseCode>=400) uPyVF-i
{ BW[5o3 i
processErrorCode(responseCode); l4'~}nn(Y
return -2; //-2 represent access is error Ry;$^.7%
} uq7T{7~<
;|ub!z9GG
7 &)]) {Q
String sHeader; =6nD0i9+
I %_MV
_"f :`
for(int i=1;;i++) 1IH[g*f
{ ~&G4)AM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B:oF;~d/,
//Utility.log(in.readLine()); S0w> hr
sHeader=httpConnection.getHeaderFieldKey(i); K!{5[G
if(sHeader!=null) B+VuUt{S
{ w8M2N]&:
if(sHeader.equals("Content-Length")) NGzgLSm\
{ Bt~s*{3$8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gtU1'p"
break; ^[# & ^[-V
} T{MC-j _T9
} z_SagU,\
else 6vz1*\:H~
break; ;b~~s.+
} D5A=,\uk
} q^Tis>*u6
catch(IOException e){e.printStackTrace ();} 3{J.xWB@:
catch(Exception e){e.printStackTrace ();} iyM^[/-R6
qc8Ta"
h8}8Lp(/'
Utility.log(nFileLength); 6 DP[g8
(!zM\sF
%`\]Y']R
return nFileLength; !Tfij(91
} ?ApRJm:T
!oMt_k X
gbGTG(:1S
//保存下载信息（文件指针位置） b~Z=:'m8
private void write_nPos() WcGXp$M
{ gg]~2f
try{ qi=3L
output = new DataOutputStream(new FileOutputStream(tmpFile)); 960qvz!
output.writeInt(nStartPos.length); Fj=NiZ=
for(int i=0;i<nStartPos.length;i++) 981!2*
{ FBYODw
// output.writeLong(nPos); 1D1b"o
output.writeLong(fileSplitterFetch.nStartPos); LM1b I4
output.writeLong(fileSplitterFetch.nEndPos); @>O&Cpt
} Es;;t83p
output.close(); &5q{viI
} !<Z{@7oH
catch(IOException e){e.printStackTrace ();} 0j@IxEPs
catch(Exception e){e.printStackTrace ();} oh&Y<d0
} Y><(?
tA qs2
h)o]TV
//读取保存的下载信息（文件指针位置） `^%GN8d}nm
private void read_nPos() H1Xovr
{ $FCw$+w
try{ . bG{T|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v MWC(m
int nCount = input.readInt(); 6y@<?08Q
nStartPos = new long[nCount]; b\L)m (
nEndPos = new long[nCount]; @,vv\M0)p
for(int i=0;i<nStartPos.length;i++) Ihef$,
{ y h-9u
nStartPos = input.readLong(); :yD@5)
nEndPos = input.readLong(); ~7BX@?
} tJ>d4A;8x
input.close(); @7|)RSBQz
} +~:0Dxv W
catch(IOException e){e.printStackTrace ();} EG1x
catch(Exception e){e.printStackTrace ();} Ph\F'xROe
} * D3
^V,@=QL3U
Kz^hQd
private void processErrorCode(int nErrorCode) Ib(,P3
{ p,^>*/O>
System.err.println("Error Code : " + nErrorCode); hGKdGu`0
} 1 '%-y
(QhAGk&lu
|Kn^w4mN
//停止文件下载 -(ER4#
public void siteStop() n(# c`t*
{ sp,(&Y]US
bStop = true; 3DHvaq q7
for(int i=0;i<nStartPos.length;i++) C9+Dw#-fV
fileSplitterFetch.splitterStop(); w`38DF@K
T/3;NXe6E
3?6Ber y=
} :if5z2PE/
} lZ+/\s,]|
//负责部分文件的抓取 p!V)55J*
**FileSplitterFetch.java n%Rjt!9
*/ /3;=xZq
package NetFox; ~M(pCSJ[
-y<rM0"NE
"URVX1#(r
import java.io.*; :4b- sg#
import java.net.*; D`5: JR-{
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public class FileSplitterFetch extends Thread { 0honHP
vV2o[\o^
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String sURL; //File URL KN|'|2/|
long nStartPos; //File Snippet Start Position /Ir 7 DZK
long nEndPos; //File Snippet End Position aw;{<?*
int nThreadID; //Thread's ID <4SF~i
boolean bDownOver = false; //Downing is over e1Dj0s?i~K
boolean bStop = false; //Stop identical NdaM9a#TZ
FileAccessI fileAccessI = null; //File Access interface +# A|Zp<
$::51#^Wg
"otr+.{`*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [)B@
{ 3<yCe%I:
this.sURL = sURL; C5d/)aC
this.nStartPos = nStart; ">rsA&hN-
this.nEndPos = nEnd; nT(!HDH
nThreadID = id; 30:HRF(:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U5T^S
} 4ZSfz#<[z
#zh6=.,7
^!XU+e+:0
public void run() )I^)*(}
{ Ul7,k\q@
while(nStartPos < nEndPos && !bStop) Zz{[Al{
{ 99=[>Ck)G
t>fA!K%{
L2do2_
try{ * <Nk%`
URL url = new URL(sURL); U!3uaz'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gt(X!iN]
httpConnection.setRequestProperty("User-Agent","NetFox"); >:(6{}b
String sProperty = "bytes="+nStartPos+"-"; S8rW'}XJ=H
httpConnection.setRequestProperty("RANGE",sProperty); U<#$w{d:
Utility.log(sProperty); )L&n)w
Y,p2eAss
g0[<9.ke
InputStream input = httpConnection.getInputStream(); 4'7 v!I9
//logResponseHead(httpConnection); IX > j8z[
+Px<DX+
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byte[] b = new byte[1024]; A@fshWrl%
int nRead; ?}!gLp
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D~t"9Z\
{ T/X?ZK(T
nStartPos += fileAccessI.write(b,0,nRead); 98<bF{#0WM
//if(nThreadID == 1) ;+#za?w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3:z4M9f
} y"%iD`{
BdRE*9.0
oqQ?2k<@
Utility.log("Thread " + nThreadID + " is over!"); j.G.Mx"
bDownOver = true; 1GyAQHx,
//nPos = fileAccessI.write (b,0,nRead); +A.a~Stt
} _tWfb}6;Zb
catch(Exception e){e.printStackTrace ();} &,6y(-
} \I`=JKYT
} s|rZ>SLL
6O[wVaC1u
-sGWSC
//打印回应的头信息 1'@lg*^9
public void logResponseHead(HttpURLConnection con) AU${0#WV_
{ >(1_Dn\
for(int i=1;;i++) F"HI>t)>
{ cVv4gQD\
String header=con.getHeaderFieldKey(i); nP3;<*T P0
if(header!=null) xSMp[j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :w&)XI34
Utility.log(header+" : "+con.getHeaderField(header)); p.W*j^';Q
else olQ8s*
break; }G:uzud10
} e*'|iuDrY
} <^X'f
Rs(CrB/M
M&BM,~
public void splitterStop() Qi'WV9ke
{ p'w"V6k('~
bStop = true; I}]@e^ ~
} ?H86Wbz
o-e,
O%q;,w{prW
} K {1ZaEH
N@du.d:
~m;MM)_V
/* ,B/p1^;.
**FileAccess.java BC0c c[x
*//文件访问(定位，写) h9OL%n 7m'
package NetFox; y:6'&`L
import java.io.*; {ALBmSapK"
]38<ly7
_*?"[TYfX
public class FileAccessI implements Serializable{ #* /W!UOu
5`{;hFl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j?KB8oY`TP
RandomAccessFile oSavedFile; ?e|:6a+[f
long nPos; 'LLQ[JJ=O
"qP^uno
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public FileAccessI() throws IOException E["t Ccg
{ JW.&uV1Z
this("",0); (>5VS
} /zP)2q^
F@(}=w^(A
huD\dmQ:]
public FileAccessI(String sName,long nPos) throws IOException 'UG}E@G
{ n; '~"AG)
oSavedFile = new RandomAccessFile(sName,"rw"); _(kwD^x6O{
this.nPos = nPos; =O:ek#Bp
oSavedFile.seek(nPos); o/[yA3^
} 8cPf0p:
BNoCE!
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public synchronized int write(byte[] b,int nStart,int nLen) =|&"/$+s
{ <UHWy&+z&
int n = -1; \ui~n:aWJ
try{ 714nUA872
oSavedFile.write(b,nStart,nLen); e^Wv*OD'
n = nLen; b|@op>UZ
} Ty|c@X
catch(IOException e) #YYvc`9
{ Py0i%pZ
e.printStackTrace (); jG ;(89QR/
} $ 5-2cL
\bl,_{z?
PL_wa(}y]D
return n; w8#>xV^~
} WK)k-A^q
4qcIoO
9@*>$6
} R/xCS.yl}
sW3D ( n
G:ngio]G0
/* %!h+
**SiteInfoBean.java jy|xDQ
*/ Z4zMa&
package NetFox; x(N}^Hu
OiEaVPSI;
P2RL\`<"
public class SiteInfoBean { oOSyOD
*G|]5
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private String sSiteURL; //Site's URL wTbIS~!gF
private String sFilePath; //Saved File's Path {#Cm> @')
private String sFileName; //Saved File's Name OWfj<#}t+
private int nSplitter; //Count of Splited Downloading File DOU?e9I2
buyz>ICP
\)kAhKtG
public SiteInfoBean() .u3W]5M|
{//nSplitter的缺省值为5 *0ntx$M-w
//default value of nSplitter is 5 HD|)D5wH|
this("","","",5); 9Bw5 t@
} X^^D[U
b#j5fEY
6{WT;W>WT:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l Nto9
{ L(S.
sSiteURL= sURL; L KR,CPz
sFilePath = sPath; FEswNB(]*
sFileName = sName; ~,7R*71
this.nSplitter = nSpiltter; YZ P
<u/({SZ&
"evV/Fg(
} K%Ml2V
}CqIKoX.
pz=Wq4l
public String getSSiteURL() P*sCrGO%
{ 7s3<}
return sSiteURL; VH65=9z
} a8$pc>2E
r{&"]'/X
mq9&To!
public void setSSiteURL(String value) ;r}<o?'RM
{ [}3Y1t{G
sSiteURL = value; aa]v7d
} OPjh"Hv
8 EH3zm4
tgnXBWA`!
public String getSFilePath() _?<Fc8F
{ Vd~k4
return sFilePath; Q)&Ztw<
} /9Xf[<
FFGTIT# {"
z"`?<A&u
public void setSFilePath(String value) MLX.MUS
{ `#U6`[[
sFilePath = value; 7]bqs"t
} -XB>&dNl)T
H\vO0 <X
wS4wED&a
public String getSFileName() Kfl+8UR5=
{ ktRdf6:~
return sFileName; Mk;j"ZDF
} i|Wn*~yFOO
plAt +*&
d-aF-
public void setSFileName(String value) 2$=HDwv
{ +/tD$
sFileName = value; _u; UU$~
} eF@E|kK
K9=_}lS@'
1;V5b+b
public int getNSplitter() -d]z_ SP@
{ oGZ9@Y)(T
return nSplitter; K(^x)w r-:
} .Pi67Kj,
XA68H!I
[A47OR
public void setNSplitter(int nCount) C Qebb:y
{ [nrP; _
nSplitter = nCount; I$&/?ns@O
} 57r)&8
} JQqDUd
|j<'[gB\p
x$E l7=.
/* \Ip<bbB0
**Utility.java >*MB_m2|
*/ 5V0=-K
package NetFox; c/u;v69r
}|d:(*
h;6@-\6
public class Utility { ':=C2x1d|
O>3'ylBQ
c?d#Bj ?
public Utility() 1Sy#*
{ _rM%N+$&d_
Z7v~;JzC#
?/\;K1c p
} DEBgb
|Yx8Ez
//线程睡眠 <i5^izg
public static void sleep(int nSecond) km^AX:r1
{ `C1LR,J
try{ ch&r.
Thread.sleep(nSecond); hug12Cu
} `'>>[*06:a
catch(Exception e) U;31}'b
{ P/_XDP./U
e.printStackTrace (); cE3co(j
} -nW{$&5AF
} +0OQ"2^&
}LRAe3N%8
//日志 ,%C$~+xjM
public static void log(String sMsg) 0\mzGfd
{ G`n-WP
System.err.println(sMsg); ]8^2(^3ct
} kK(633s
L*_xu _F
8c~H![2u
public static void log(int sMsg) oeIS&O.K
{ 9.R_=
System.err.println(sMsg); =FE,G*
} IoX(Pa
} ~7m+cWC-+
F,D&
Eg9502Bl~8
/* lyV]-w
**TestMethod.java C{Fo^-3
*/ 5xiYCOy
package NetFox; L+u_153
GP[$&8\M
8dpVB#]pp,
public class TestMethod { acH.L_B:
BP7_o63/G
:sn}D~
public TestMethod() )KNFS,5
{ ///xx/weblogic60b2_win.exe FUH1Z+9
try{ 0QPipuP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); us]ah~U6A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Kb}N!<Z*
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q.N^1?(>k
fileFetch.start(); X2{3I\'Ft
} T4UY%E!0
catch(Exception e){e.printStackTrace ();} CkP!4^J qQ
N5s_o0K4TU
Vf:t!'WD?2
} U3Q'ZT
.`iq+i~
Uq&|iB#mF
public static void main(String[] args) K)k!`du!6
{ 2q#$?qs_b
new TestMethod(); B<oi,S
} LR^b?.#>
} mF_/Rhu
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