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http断点续传简单实现(java)

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/* *+j{9LK  
**SiteFileFetch.java AaYrVf 9!  
*/ 4)HWPX  
package NetFox; ZQ9oZHUm  
import java.io.*; |3:=qpT-  
import java.net.*; /=m9s  
X$ B]P 7G7  
i!W8Q$V  
public class SiteFileFetch extends Thread { s#4ew}  
zQ5jx5B":  
%<C G|]W  
SiteInfoBean siteInfoBean = null; //文件信息Bean @'r`(o3z!Z  
long[] nStartPos; //开始位置 NhK(HTsvK  
long[] nEndPos; //结束位置 LAY)">*49H  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 xbrmPGpW$  
long nFileLength; //文件长度 !@Sf>DM"  
boolean bFirst = true; //是否第一次取文件 `Kc %S^C'  
boolean bStop = false; //停止标志 "h^#<bPN  
File tmpFile; //文件下载的临时信息 :.S41S   
DataOutputStream output; //输出到文件的输出流 Cre0e$ a  
R_Gq8t$  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) :@>br+S  
public SiteFileFetch(SiteInfoBean bean) throws IOException _%Jl&0%q  
{ nG ^M 2)(8  
siteInfoBean = bean; @CaD8%j{  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ]EM)_:tRf  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); K"k"ml<4E  
if(tmpFile.exists ()) ,-7/]h,l  
{ v!#`W  
bFirst = false; Kcw1uLb  
read_nPos(); bmO__1  
} )qyx|D  
else *)NR$9lGv  
{ !HR2Rfl  
nStartPos = new long[bean.getNSplitter()]; :%uyy5AZ  
nEndPos = new long[bean.getNSplitter()]; ^EUOmVN  
} 7z g)h  
Y-%l7GErhL  
#U$YZ#B  
:n+y/6 *  
}  &6\r  
4h;f>BG  
$&=4.7Yt  
public void run() %;<k(5bhGJ  
{ W>?f^C!+m  
//获得文件长度 [>$\s=` h  
//分割文件 IYfV~+P  
//实例FileSplitterFetch )e|$K= D  
//启动FileSplitterFetch线程 q'%[[<  
//等待子线程返回 ^ J#?hHz  
try{ ^I(oy.6?=p  
if(bFirst) l$k]O  
{ Ei{(  
nFileLength = getFileSize(); #.E\,N'  
if(nFileLength == -1) K-2o9No?j`  
{ 0a2$P+p  
System.err.println("File Length is not known!"); ?qf:_G  
} =E [4H  
else if(nFileLength == -2) $@[dm)M  
{ J ?ztn  
System.err.println("File is not access!"); }t@f |TX  
} m4P hn~>Gg  
else  3}>:  
{ L _vblUDq  
for(int i=0;i<nStartPos.length;i++) Q^a&qYK  
{ pBSq%Hy:  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); BKE\SWu  
} ~rgf{oGz  
for(int i=0;i<nEndPos.length-1;i++) C<[d  
{ Y|%anTP  
nEndPos = nStartPos[i+1]; $i,6B9  
} DO7- =74=  
nEndPos[nEndPos.length-1] = nFileLength; G0I~&?nDa  
} TJHN/Z/  
} 8%;}LK  
<Jwi ~I=^  
z>cIiprX  
//启动子线程 F^.om2V|9  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ki;!WhF~  
for(int i=0;i<nStartPos.length;i++) B;xZ% M]  
{ iEiu%T>  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]$m#1Kj  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bK ?1MiXb  
nStartPos,nEndPos,i); "bD+/\ z  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @T<ad7g-2J  
fileSplitterFetch.start(); A#v|@sul  
} q%OcLZ<,  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4 t&gW  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >EBZ$X  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WW//heJe-  
nEndPos = " + nFileLength); [3t0M5x w  
// fileSplitterFetch[nPos.length-1].start(); Dh hG$  
'8s>rH5[V  
+mJ :PAy4  
//等待子线程结束 XMt u"K  
//int count = 0; bH'S.RWp=  
//是否结束while循环 ?r{TOj n  
boolean breakWhile = false; XOu+&wOu  
CTl(_g  
kcLj Kp  
while(!bStop)  7]p>XAb  
{ _^_5K(Uq  
write_nPos(); E)C.eW /  
Utility.sleep(500); ~'NX~<m  
breakWhile = true; yOX&cZ[  
%9t{Z1$  
{I4%   
for(int i=0;i<nStartPos.length;i++) @)o0GHNP  
{ rpUy$qrRc  
if(!fileSplitterFetch.bDownOver) mbF(tSy  
{ +J"'  'cZ  
breakWhile = false; n4^~gT%b5]  
break; L<bYRGz  
} J"diFz+20  
} fx<FIj7  
if(breakWhile) sB?2*S"X)<  
break; 8$\Za,)g  
6tOCZ'f  
Dq?E\  
//count++; fZ[kh{|  
//if(count>4) y&1%1 #8F  
// siteStop(); @'*eC}\E  
} 'z)hG#{I  
LyGUvi  
yC W*fIaq  
System.err.println("文件下载结束!"); ITVQLQ  
} }x]&L/  
catch(Exception e){e.printStackTrace ();} ypH8QfxLTr  
} B9YsA?hg  
 BY3bpR  
{1jpLdCbV^  
//获得文件长度 vwVVBG;t  
public long getFileSize() yB.G=90  
{ IrJ+Jov  
int nFileLength = -1; doBNghS  
try{ Ski G2n]  
URL url = new URL(siteInfoBean.getSSiteURL()); 0|ZVA+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {{32jU7<  
httpConnection.setRequestProperty("User-Agent","NetFox"); uM<|@`&b  
O#vn)+Y,*  
q%>7L<r  
int responseCode=httpConnection.getResponseCode(); @|BD|{k  
if(responseCode>=400) uG;?vvg>  
{ 4:D:| r  
processErrorCode(responseCode); b6|Z"{TI _  
return -2; //-2 represent access is error &M[MEO`t8  
} )Nbc/nB$  
_mXs4  
|8bE9qt.P  
String sHeader; lK*jhW?3:  
fmFzW*,E  
S.: 7k9  
for(int i=1;;i++) \^9pW 2v  
{ EJ`Q8uz  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :/6()_>bO  
//Utility.log(in.readLine()); COSTV>s;  
sHeader=httpConnection.getHeaderFieldKey(i); JT04vm4  
if(sHeader!=null) 3E,DipHg  
{ dByjcTPA  
if(sHeader.equals("Content-Length")) \QGa 4_#  
{ wFvT0  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Cc!J1)  
break; s O=4IBE  
} HMV)U{  
} :N2E}hxk  
else W .U+.hR  
break; T^]7R4 Fg  
} /YFa ;2 W  
} Q/py qe G  
catch(IOException e){e.printStackTrace ();} qEQAn/&  
catch(Exception e){e.printStackTrace ();} \]8VwsP  
qp>N^)>  
K\(6 rS}N  
Utility.log(nFileLength); 7(Cx!Yb  
lm$;:Roj*  
P`EgA  
return nFileLength; #-{N Ws\  
} [(ygisqt  
H -,TS^W  
Iyyo3awc  
//保存下载信息(文件指针位置) 0/Z !5-.  
private void write_nPos() hsz^rZ  
{ Qs l80~n_7  
try{ |n`PESf_  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8}BS2C%P  
output.writeInt(nStartPos.length); 2bLI%gg3  
for(int i=0;i<nStartPos.length;i++) r+S;B[Vd  
{ @}DFp`~5|  
// output.writeLong(nPos); z]=8eV\  
output.writeLong(fileSplitterFetch.nStartPos); v L}T~_=3  
output.writeLong(fileSplitterFetch.nEndPos); vd (?$  
}  )3%@9  
output.close(); T@P!L  
} 'wvMH;}u  
catch(IOException e){e.printStackTrace ();} >b48>@~bY  
catch(Exception e){e.printStackTrace ();} SE)nD@:  
} 514Z<omrK  
!n<o)DsZR  
E(4w5=8TI  
//读取保存的下载信息(文件指针位置) uv]{1S{tb  
private void read_nPos() s8vKKvs`9  
{ _Yq@FOu  
try{ u,o1{% O  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BvK QlT  
int nCount = input.readInt(); I9 &lO/c0  
nStartPos = new long[nCount]; Y: psZ  
nEndPos = new long[nCount]; W`M6J}oG  
for(int i=0;i<nStartPos.length;i++) :q (&$  
{ {eQWO.C{  
nStartPos = input.readLong(); /t5p-  
nEndPos = input.readLong(); S^N {wZo  
} opp!0:jS*  
input.close(); VagT_D  
} PeTA$Yl  
catch(IOException e){e.printStackTrace ();} K_ke2{4Jm  
catch(Exception e){e.printStackTrace ();} u =J&~  
} q0./O|Dj   
3t" 4TjAy  
S3Y2O x  
private void processErrorCode(int nErrorCode) uMmXs% 9T  
{ QyGnDomQ  
System.err.println("Error Code : " + nErrorCode); I7(?;MpI  
} P^)q=A8Z#  
7L3ik;>  
Riry_   
//停止文件下载 $yu?.b 9H#  
public void siteStop() lAi2,bz"  
{ 7%;_kFRV  
bStop = true; v }\,o%t^  
for(int i=0;i<nStartPos.length;i++) 9 OT,TpA  
fileSplitterFetch.splitterStop(); ynwG\V  
'V&Y[7Aeq  
6b=q-0yj  
} 0 n vSvk  
} UE"GJt`I  
//负责部分文件的抓取 ,wAz^cK|  
**FileSplitterFetch.java o{WyQ&2N  
*/ 1AD]v<M  
package NetFox; \6!W05[ Q  
hdma=KqZ(  
J n&7C  
import java.io.*; }q[Bd  
import java.net.*; h2Bz F  
vbG]mMJ  
~O6\6$3b5E  
public class FileSplitterFetch extends Thread { {XCf-{a]~  
7'lZg<z{~j  
qxOi>v0\H  
String sURL; //File URL N.do "  
long nStartPos; //File Snippet Start Position PkuTg";  
long nEndPos; //File Snippet End Position 3'`dFY,  
int nThreadID; //Thread's ID !wz/c M;  
boolean bDownOver = false; //Downing is over F7*wQ{~  
boolean bStop = false; //Stop identical BMyzjteS+  
FileAccessI fileAccessI = null; //File Access interface 3L5r*fa  
4Y\wnwI  
'@nbqM  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j]rz] k  
{ Cfu=u *u  
this.sURL = sURL; s%4M$ e  
this.nStartPos = nStart; w?Ju5 5  
this.nEndPos = nEnd; 5e8AmY8;  
nThreadID = id; T1WWK'  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5s{j = .O  
} yR5XJ;Tct  
ne}+E  
EbNd=Z'J  
public void run() Dh4 6o|P  
{ 8 .>/6M  
while(nStartPos < nEndPos && !bStop) l`9t}  
{ 0#o/^Ah  
k(VB+k"3  
,5 j"ruZ  
try{ Q,T"ZdQ  
URL url = new URL(sURL); O`1!  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Hh;:`;}  
httpConnection.setRequestProperty("User-Agent","NetFox"); o`S ?  
String sProperty = "bytes="+nStartPos+"-"; OWq'[T4  
httpConnection.setRequestProperty("RANGE",sProperty); k44Q):ncY7  
Utility.log(sProperty); 5*%#o  
"UFs~S|e  
0pb '\lA  
InputStream input = httpConnection.getInputStream(); m7c*)"^  
//logResponseHead(httpConnection); QF2q^[>w6  
CT a#Q,  
igL<g  
byte[] b = new byte[1024]; E>LkJSy=  
int nRead; 5Z/7kU= I  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T4/fdORS  
{ SMr13%KN/  
nStartPos += fileAccessI.write(b,0,nRead); n{0Ld - zH  
//if(nThreadID == 1) qFX~[h8i+  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U @v*0  
} PXoz*)tk  
:(|'S4z  
E_z;s3AXQ  
Utility.log("Thread " + nThreadID + " is over!"); uQ$^;Pr  
bDownOver = true; :'L2J  
//nPos = fileAccessI.write (b,0,nRead); CbBSFKM  
} D B526O* [  
catch(Exception e){e.printStackTrace ();} 6Q&r0>^{  
} WS8+7O'1\  
} r;>+)**@vl  
X r63?N  
BAj-akc f  
//打印回应的头信息 #hfuH=&oh  
public void logResponseHead(HttpURLConnection con) POI.]1i  
{ :,12")N  
for(int i=1;;i++) @Hb'8F  
{ gU^$Sx7'  
String header=con.getHeaderFieldKey(i); Qp,DL@mp>8  
if(header!=null) Y}*\[}l:&x  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y/<lWbj*A  
Utility.log(header+" : "+con.getHeaderField(header)); B5V_e!*5F*  
else W1Lr_z6  
break; l- pe4x  
} `nXVE+E@  
} <:FP4e "(  
c !ZM  
AUVgPXOwd  
public void splitterStop() Pz#7h*;cw.  
{ <:/&&@2  
bStop = true; }eQRN<}P  
} #PDf,^  
)0vU k  
AsS$C&^  
} TC~Q G$NW  
1(zsOeX  
jc[_I&Oc_  
/* =(a1+. O  
**FileAccess.java .?p\n7  
*//文件访问(定位,写) )D'^3) FF  
package NetFox; J`q]6qf#  
import java.io.*; \;-fi.Hrf$  
[ xOzzp4  
- K%,^6  
public class FileAccessI implements Serializable{ tt?58dm|  
v%k9M{  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n?\ nn3  
RandomAccessFile oSavedFile; I1X /Lj=  
long nPos; scuHmY0  
9YsR~SM  
 nVu&/  
public FileAccessI() throws IOException ANIz, LS  
{ HkV1sT  
this("",0); -[= drj9I  
} k4qp u=@U  
[S.ZJUns  
<PPNhf8  
public FileAccessI(String sName,long nPos) throws IOException ^l^fD t  
{ -U<Upn)2  
oSavedFile = new RandomAccessFile(sName,"rw"); >@WX>0`ht  
this.nPos = nPos; 87 }&`  
oSavedFile.seek(nPos); `c/*H29  
} YY?a>j."a  
uj%skOD6Z  
,D\GGRw  
public synchronized int write(byte[] b,int nStart,int nLen) h2ZkCML  
{ hS[ yNwD  
int n = -1; =. y*_Ja  
try{ *Nyev]8  
oSavedFile.write(b,nStart,nLen); `X,yM-(  
n = nLen; rC:?l(8ng3  
} L,d LE-L  
catch(IOException e) TI9UXa:V\  
{ w ;daC(:  
e.printStackTrace (); hYQ_45Z*?  
} MYBx&]!\  
yCJFo  
r]W  
return n; 7nbB^2  
} _#$ *y  
?JV|dM  
6"c1;P!4   
} 'Dvv?>=&  
mh<=[J,%p  
eI1GXQ%  
/* Ca%g_B0t  
**SiteInfoBean.java }SIGPVM  
*/ oG$)UTzGc  
package NetFox; \#68;)+=  
T&86A\D\z  
"x@='>:$  
public class SiteInfoBean { p8s:g~ W  
"<}&GcJbz  
J5h+s-'  
private String sSiteURL; //Site's URL &V|>dLT>A  
private String sFilePath; //Saved File's Path 5Z4- Z  
private String sFileName; //Saved File's Name Y(\T- bI  
private int nSplitter; //Count of Splited Downloading File )BfT7{WN  
^kS T  
.(J?a"  
public SiteInfoBean() iHf-{[[Z  
{//nSplitter的缺省值为5 {pb>$G:gfx  
//default value of nSplitter is 5 64-#}3zL  
this("","","",5); xEuN   
} T#pk]c6Q  
`%3 /   
DK0.R]&4(  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7bxA]s{m  
{ \A `hj~  
sSiteURL= sURL; JT fd#g?I  
sFilePath = sPath; <p;k)S2J  
sFileName = sName; E7Cy(LO  
this.nSplitter = nSpiltter; +UJuB  
_C\[DR0n  
z} '!eCl  
} 2oJb)CB  
1<ro7A4hK  
65ly2gl  
public String getSSiteURL() m]*Bx%-1c  
{ 6Es? MW=  
return sSiteURL; qyHZ M}/  
} s:00yQ  
iCP/P%  
!ZDzEP*  
public void setSSiteURL(String value) O4<g%.HC6  
{ @|a>&~xX  
sSiteURL = value; 8G>>i)Sbg  
} 0J.dG/I%  
CIjZG?A  
8@NH%zWBp  
public String getSFilePath() :|o<SZ  
{ ::n;VY2&  
return sFilePath; 4/ X/>Y1  
} WWT",gio  
xf%4, JQ  
Iqs+r?  
public void setSFilePath(String value) 2cu#lMq  
{  ]*O/+  
sFilePath = value; DoC(Z)o  
} :a:[.  
A?G IBjs  
?)'~~ @NkH  
public String getSFileName() Qr# 1u  
{ (]/9-\6(#  
return sFileName; Cw5%\K$=  
} c62=*] ,  
2/,0iwj-  
FZB~|3eq{  
public void setSFileName(String value) \yrisp#`  
{ 0oy-os  
sFileName = value; ozsxXBh-`'  
} &iN--~}!$  
wV?,Z!\Z  
`k\grr.J  
public int getNSplitter() Li 2Zndp  
{ \3Oij^l 0  
return nSplitter; -{h   
} l0*Gb  
K[ .JlIP  
!gwjN_ZJ^  
public void setNSplitter(int nCount) 3E}EBJLsZ  
{ Dj\e@?Y  
nSplitter = nCount; DjMf,wX-{  
} (Lh#`L?x  
} s!/TU{8J  
I[o*RKT'"  
y( r1I[W'  
/* r%Rs0)$yj  
**Utility.java &PcyKpyd  
*/ ashcvn~z  
package NetFox; fJjgq)9  
iq?#rb P#I  
9^P2I)aD  
public class Utility { ! BU)K'mj  
'+<(;2Z vL  
F?Ju?? O  
public Utility() \^*< y-jL  
{ PXP`ZLF  
')+0nPV  
O?bK%P]ay  
} m9M FwfZ  
jc_\'Gr+[  
//线程睡眠 HOt>}x  
public static void sleep(int nSecond) '#\D]5  
{ <<MjC5  
try{ I 5ag6l  
Thread.sleep(nSecond); ps1YQ3Ep&  
} ;D ~L|  
catch(Exception e) lfk9+)  
{ n)8Yj/5  
e.printStackTrace (); D-9\~gvh  
} [n,?WwC  
} EruP  
,KW;2t*IQ@  
//日志 Hv#q:R8  
public static void log(String sMsg) 9-*NW0  
{ ]kktoP|D  
System.err.println(sMsg); B%<e FFV\  
} "oJ(J{Jat  
dOa!htx]  
S_J :&9L  
public static void log(int sMsg) "YFls#4H-  
{ h?@G$%2  
System.err.println(sMsg); )tZ`K |  
} .M|>u_<Qd  
} f<[jwhCWV  
i~=s^8n`l  
l52a\/  
/* jSt mS2n  
**TestMethod.java k D~uGA  
*/ !7H6i#g*  
package NetFox; zLjgCS<7  
g+q@i{Yn  
E|Bd>G  
public class TestMethod { $]d*0^J 6  
^Uw[x\%#gD  
p|6v~  
public TestMethod() l_FGZ!7  
{ ///xx/weblogic60b2_win.exe aP~gaSx  
try{ ph30'"[Z}  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xer@A;c  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7-iIay1h"  
SiteFileFetch fileFetch = new SiteFileFetch(bean); V:K;] h*!  
fileFetch.start(); /dHs &SU,  
} jThbeY[  
catch(Exception e){e.printStackTrace ();} (;o*eFC F  
irxz l3   
mE $dO3  
} ~P1_BD(  
!oSLl.fQd  
4-4?IwS  
public static void main(String[] args) euRss#;  
{ Z-Wfcnk  
new TestMethod(); :Am-8  
} a4GWuozl  
} u?Hb(xZtg=  
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