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http断点续传简单实现(java)

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/* ^%X\ }><  
**SiteFileFetch.java Q fyERa\rb  
*/ ;Kq?*H  
package NetFox; ^oB1 &G  
import java.io.*; qf=[*ZY  
import java.net.*; fG$.DvJuK  
JiLrwPex[  
ftqW3VW  
public class SiteFileFetch extends Thread { %+! 9  
;F(01  
q4ko}jn  
SiteInfoBean siteInfoBean = null; //文件信息Bean 3 <lhoD  
long[] nStartPos; //开始位置 nJ#@W b@  
long[] nEndPos; //结束位置 U(]5U^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 2y7q x1$C  
long nFileLength; //文件长度 M)pi)$&c  
boolean bFirst = true; //是否第一次取文件 p33GKg0i+(  
boolean bStop = false; //停止标志 o4f9EJY   
File tmpFile; //文件下载的临时信息 Odtck9L  
DataOutputStream output; //输出到文件的输出流 X$&Sw3c  
}3_G|  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) *3 8Y;{ 4  
public SiteFileFetch(SiteInfoBean bean) throws IOException 2^ZPO4|  
{ I^Jp )k*z  
siteInfoBean = bean; {=4:Tgw  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); +<WT$ddK=5  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ~wg^>!E  
if(tmpFile.exists ()) =<h=">}5'  
{ ;H r@0f  
bFirst = false; 1WN93 SQ=  
read_nPos(); a&VJ YAB  
} I3$vw7}5Y  
else wSyu^KDz  
{ RX\O'Zwlj  
nStartPos = new long[bean.getNSplitter()]; W1`ZS*12D  
nEndPos = new long[bean.getNSplitter()]; q;Pz B4#  
} 2^M+s\p  
(4{9 QO  
WA5kX SdIb  
r3vj o(  
} #7T={mh  
\)uad5`N  
X*"O'XCA  
public void run() 7uNI  
{ bK1`a{  
//获得文件长度 ,ToEK Id  
//分割文件 aKtTx~$@  
//实例FileSplitterFetch M':.b+xN  
//启动FileSplitterFetch线程 <ijmkNVS  
//等待子线程返回 ?R:Hj=.  
try{ rO%+)M$A  
if(bFirst) *~^^A9C8  
{ @il}0  
nFileLength = getFileSize(); P`"DepeD  
if(nFileLength == -1) v[3sg2.  
{ ,!4_Uc  
System.err.println("File Length is not known!"); x,_Ucc.  
} e' VXyf  
else if(nFileLength == -2) OR8o%AxL7  
{ /n:fxdhe  
System.err.println("File is not access!"); S]g)^f'a65  
} )ixE  
else CnYX\^Ow  
{ ,SwaDWNO  
for(int i=0;i<nStartPos.length;i++) e'&{KD,-T  
{ QLG,r^  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); !:{_<C"D  
} 59 Y=VS  
for(int i=0;i<nEndPos.length-1;i++) `VN<6o(  
{ \ y",Qq?  
nEndPos = nStartPos[i+1]; iL1so+di  
} yqI|BF`  
nEndPos[nEndPos.length-1] = nFileLength; `BD`pa7.%  
} \s'6)_  
} Y%@'a~  
Bx >@HU  
pBkPn+@  
//启动子线程 M-|2W~YU  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B=|sLs`I  
for(int i=0;i<nStartPos.length;i++) IPR396J+-  
{ heA\6W:u&  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RA/yvr  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7yl'!uz)9  
nStartPos,nEndPos,i); 2fB@zF  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +Ti@M1A&  
fileSplitterFetch.start(); 'L/TaP/3  
} .`XA6e(8KR  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iX p8u**  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l !v#6#iq  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E!M+37/  
nEndPos = " + nFileLength); +%v4Ci"%y  
// fileSplitterFetch[nPos.length-1].start(); Cj9Tj'0@I+  
\gpKQt0  
rC16?RovQ@  
//等待子线程结束 17d$gZ1O:  
//int count = 0; t:7jlD!d  
//是否结束while循环 b87o6"j  
boolean breakWhile = false; CuNHDYQ&3  
M(f'qFY=K  
nE84W$\  
while(!bStop) ~Y[1Me  
{ fHi+PEbR  
write_nPos(); qFk(UazN  
Utility.sleep(500); 04t_  
breakWhile = true; Nfh(2g K+  
7Wu2gky3  
NYeg,{q  
for(int i=0;i<nStartPos.length;i++) PYe>`X?  
{ oL;/Qan  
if(!fileSplitterFetch.bDownOver) N}= - +E|  
{ ;21JM2JI8  
breakWhile = false; {Xj%JE[V  
break; CiSG=obw  
} I j /J  
} P.Bk-#}$  
if(breakWhile) ->(B: Cz  
break; 79DC]48M  
j>iM(8`t1  
hCgNS1%4  
//count++; &AVi4zV  
//if(count>4) p:jrqjLp  
// siteStop(); 4]GyuY  
} m[f\I^ \%8  
5cU8GgN`  
53QP~[F8R]  
System.err.println("文件下载结束!"); ilP&ctn6+c  
} J98K:SAR  
catch(Exception e){e.printStackTrace ();} JY,+eD  
} z$NLFJvy_-  
u(R`}C?P'  
e+mD$(h  
//获得文件长度 Z6p>R;9n  
public long getFileSize() R/W&~t  
{ H;6V  
int nFileLength = -1; ` T!O )5  
try{ oaHBz_pg  
URL url = new URL(siteInfoBean.getSSiteURL()); -vyC,A  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -Da_#_F  
httpConnection.setRequestProperty("User-Agent","NetFox"); >&R|t_ypw  
]:;gk&P  
&Lw| t_y  
int responseCode=httpConnection.getResponseCode(); Z& %61jGK  
if(responseCode>=400) ?6Gq &  
{ w%ForDB>P  
processErrorCode(responseCode); O  tr@jgw  
return -2; //-2 represent access is error F2&KTK  
} l},%g%}iMU  
. XmD[=  
]O[f#lG  
String sHeader; zri<'W  
Ah,Zm4:  
pnD#RvmW2e  
for(int i=1;;i++) W +S>/`N  
{ Y9WH%  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,O2F}5|;  
//Utility.log(in.readLine()); +#W5Qb}VR  
sHeader=httpConnection.getHeaderFieldKey(i); Pw")|85  
if(sHeader!=null) r~sGot+sQA  
{ R:E`  
if(sHeader.equals("Content-Length")) tFGLqR%/  
{ U+K_eEI0_I  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h3:k$`_  
break; =X`/.:%|[  
} u*M*Wp Y  
} 7 MfpZgC  
else 0<Y)yNsV  
break; 6ugBbP +^  
} n8?gZ` W  
} qRU8uu   
catch(IOException e){e.printStackTrace ();} yCz? V[49  
catch(Exception e){e.printStackTrace ();} mBNa;6w?{*  
HJ2]xe09  
W?$ ImW  
Utility.log(nFileLength); {PfE7KH  
x*YJ :t  
B *:6U+I  
return nFileLength; a`T{ 5*@  
} p~r +2(J  
P6X 4m(t  
-X |G  
//保存下载信息(文件指针位置) k -SUp8}g  
private void write_nPos() `0sa94H1[  
{ 4Ld0AApncy  
try{ ,3^N_>d$W  
output = new DataOutputStream(new FileOutputStream(tmpFile)); jtZ@`io  
output.writeInt(nStartPos.length); q* m%Fv  
for(int i=0;i<nStartPos.length;i++) T-27E$0  
{ W nVX)o  
// output.writeLong(nPos); r`" ?K]rI  
output.writeLong(fileSplitterFetch.nStartPos); [E=t{&t  
output.writeLong(fileSplitterFetch.nEndPos); r:u5+A  
} 7Npz {C{I  
output.close(); 1{DHlyA6g  
} 5H<rI?  
catch(IOException e){e.printStackTrace ();} 7)[4|I  
catch(Exception e){e.printStackTrace ();} ;'nu9FU*O  
} -tDmzuD6  
dLv\H&  
{4#'`Eejj  
//读取保存的下载信息(文件指针位置) .>&kA f.  
private void read_nPos() |vzGFfRI  
{ ,cpPXcz?,  
try{ p#3P`I>ZrT  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8TuOf(qE  
int nCount = input.readInt(); iA=9Lel  
nStartPos = new long[nCount]; #A?U_32z/2  
nEndPos = new long[nCount]; Y,?rykRj  
for(int i=0;i<nStartPos.length;i++) 4j/8Otn  
{ VN*^pAzlF  
nStartPos = input.readLong(); G:f]z;Xdp  
nEndPos = input.readLong(); W<kJ%42^j  
} W| ~Ehg  
input.close(); " >;},$  
} rlW  
catch(IOException e){e.printStackTrace ();} t + Fm?  
catch(Exception e){e.printStackTrace ();} (]rtBeT  
} U2!9Tl9".  
Uw4KdC  
J}lBK P:-*  
private void processErrorCode(int nErrorCode) h@l5MH=|%  
{ J,k9?nkY /  
System.err.println("Error Code : " + nErrorCode); jiz"`,-},O  
} y~;Kf0~  
|odl~juU  
oT.g@kf=H  
//停止文件下载 )mJl-u[0+  
public void siteStop() 9V("K  
{ ~- JkuRJ\  
bStop = true; 'Aai.PE:  
for(int i=0;i<nStartPos.length;i++) :jgwp~l  
fileSplitterFetch.splitterStop(); @ScH"I];uA  
<[kdF")  
;L++H5Kz6  
} DTPYCG&%  
} ho;Km  
//负责部分文件的抓取 z`5d,M  
**FileSplitterFetch.java KE6[u*\  
*/ r( :"BQ  
package NetFox; } 5FdX3YR  
u\.7#D>  
!ai, \  
import java.io.*; 80LKxA;5N  
import java.net.*; Fz~-m#Ts  
PL[7|_%  
SX$v&L<  
public class FileSplitterFetch extends Thread { -(ABQgSO]  
TnCN2#BO  
CUaI66  
String sURL; //File URL d7qHUx'=z  
long nStartPos; //File Snippet Start Position la[xbv   
long nEndPos; //File Snippet End Position 1|Us"GQ (n  
int nThreadID; //Thread's ID MkF:1-=L  
boolean bDownOver = false; //Downing is over Z>{3t/`  
boolean bStop = false; //Stop identical ,?P@ :S<8  
FileAccessI fileAccessI = null; //File Access interface 1nye.i~  
KAT4C 4=,  
:"#EQq]ct  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException swntz  
{ Wf +j/RxTi  
this.sURL = sURL; Nl"< $/  
this.nStartPos = nStart; %tT&/F  
this.nEndPos = nEnd; PTXy:>]M  
nThreadID = id; +'Ec)7m  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T XWi5f[  
} 9# IKb:9k  
s+8 v7ZJ  
$WI=a-;_e  
public void run() h/j+ b.|  
{ y2bL!Y<s9  
while(nStartPos < nEndPos && !bStop) ?kqo~twJ  
{ *tC]Z&5  
gBA UrY%]  
 |W];8  
try{ SQ9s  
URL url = new URL(sURL); '5\7>2fI  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -{dsl|Dl  
httpConnection.setRequestProperty("User-Agent","NetFox"); \BOZhXfl'  
String sProperty = "bytes="+nStartPos+"-"; eZ#nZB  
httpConnection.setRequestProperty("RANGE",sProperty); 7{e0^V,\k  
Utility.log(sProperty); dlsVE~_G  
rLw3\>y  
{{7%z4l  
InputStream input = httpConnection.getInputStream(); ;cgc\xm>  
//logResponseHead(httpConnection); vtM!?#  
tt2`N3Eu\  
Yq-Nk:H|  
byte[] b = new byte[1024]; Z[[ou?c  
int nRead; }u8o*P|,  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c%9wI*l  
{ tkx1iBW=  
nStartPos += fileAccessI.write(b,0,nRead); ,iY/\ U''  
//if(nThreadID == 1) ?&W1lYY  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L8("1_  
} u4*7 n-(  
=X6WK7^0  
L5=Tj4`  
Utility.log("Thread " + nThreadID + " is over!"); ]y= ff6Q  
bDownOver = true; =LEKFXqM  
//nPos = fileAccessI.write (b,0,nRead); 28J ; 9  
} l ps 6lnh  
catch(Exception e){e.printStackTrace ();} ~?TG SD@(  
} *$mDu,'8  
} 3)ac  
ICwhqH&  
EkS7j>:  
//打印回应的头信息 p_T>"v  
public void logResponseHead(HttpURLConnection con) pcwkO  
{ __<u!;f  
for(int i=1;;i++) vcTWe$;Q  
{ R r7r5  
String header=con.getHeaderFieldKey(i); gRA}sF  
if(header!=null) JbN@AX:%  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); # hvLv  
Utility.log(header+" : "+con.getHeaderField(header)); [!9 dA.tF  
else MN1 kR  
break; Ba==Ri8$  
} oo sbf#V  
} o;bK 7D  
]4f;%pE  
rrBu6\D  
public void splitterStop() YYfX@`\  
{ $OOZ-+8  
bStop = true; J!r,ktO^U?  
} *((wp4b  
o|#Mq"od  
nk.m G ny  
} |^&n\vXv  
GCSR)i|  
|tL57Wu93  
/* za{z2# aJ  
**FileAccess.java i oCoFj  
*//文件访问(定位,写) .Y B}w  
package NetFox; {;.q?mj  
import java.io.*; ie4keVlXc  
]iu}5]?)  
Fe8JsB-  
public class FileAccessI implements Serializable{ aRFLh  
vd>K=! J  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #sl_ BC9  
RandomAccessFile oSavedFile; -"J6 |Y#8  
long nPos; fBCW/<Z  
,nn5LQ|l.j  
H:9Z.|{Gv  
public FileAccessI() throws IOException gp07I{0~m  
{ WT(inf[  
this("",0); RiHOX&-7  
} ^`b&fb v  
scmn-4j'{  
7P3PQ%:  
public FileAccessI(String sName,long nPos) throws IOException HSq.0vYl6  
{ Z4YQ5O5  
oSavedFile = new RandomAccessFile(sName,"rw"); zJ;K4)"j  
this.nPos = nPos; /18Z4TA  
oSavedFile.seek(nPos); IT,d(UV_  
} T3po.Km\{  
7U=|>)Q0s  
q^{Z"ifL  
public synchronized int write(byte[] b,int nStart,int nLen) HI}$Z =C  
{ JTT"t@__  
int n = -1; x!\FB.h4!(  
try{ M6(oJ*  
oSavedFile.write(b,nStart,nLen); &P8 Run  
n = nLen; `x;8,7W;B  
} 3Cq/ o'  
catch(IOException e) 9G8n'jWyY  
{ Q _}i8p '  
e.printStackTrace (); x;H#-^LxW=  
} k< b`v&G  
%9.] bd|%F  
y/' ^r?  
return n; }@IRReQ  
} oZvQ/|:p!  
RG(m:N  
nnBgTtsC]  
} "BB#[@  
z`gdE0@;d3  
_!FM^N}|  
/* gv=mz,z  
**SiteInfoBean.java Q;O\tl  
*/ S312h'K j  
package NetFox; `?{Hs+4P5  
COS(pfC  
75Xi%mlE7  
public class SiteInfoBean { A`4Di8'Me  
Ks&~VU  
GD1=Fb"&)  
private String sSiteURL; //Site's URL  & y1' J  
private String sFilePath; //Saved File's Path %N)o*H&  
private String sFileName; //Saved File's Name i<D}"h|  
private int nSplitter; //Count of Splited Downloading File k*bfq?E a  
<YbOO{  
)c@I|L  
public SiteInfoBean() Vv(!Ki}  
{//nSplitter的缺省值为5 5qco4@8  
//default value of nSplitter is 5 9IL#\:d1  
this("","","",5); H[o'j@0  
} 2G"mm (   
x&3!z[m@@  
1E Lzzn  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R7us9qM4e  
{ s~$kzEtjjU  
sSiteURL= sURL; L1u  
sFilePath = sPath; cOUsbxYTD  
sFileName = sName; bo&!oY#  
this.nSplitter = nSpiltter; P,RCbPC4  
ogv86d  
<[xxCW(2  
} {+f@7^/i.  
=Mq=\T  
cHK)e2 r  
public String getSSiteURL() L>{E8qv>w  
{ lj.z>  
return sSiteURL; c1wM"  
} YZ\$b=-  
,_`\c7@  
 ,[ +  
public void setSSiteURL(String value) zW%-Z6%D  
{ ?PWD[mQE\  
sSiteURL = value; +S M $#  
} 3y>.1  
.hgc1  
V_U$JKJ1=  
public String getSFilePath() 9A\J*OU  
{ ,oDZ:";  
return sFilePath; xk86?2b{)  
} +8[h&  
;^:~xJFx|  
GZQ)Tz R  
public void setSFilePath(String value) >8SX,  
{ ;: Hfkyy]  
sFilePath = value; ksY^w+>(!  
} =(*Eh=Pw  
oypq3V=5  
.D^k0V  
public String getSFileName() >U"f1q*$  
{ Opmb   
return sFileName; !`,6E`Y#  
} u4$d#0sA  
j]J2,J  
sx8mba(  
public void setSFileName(String value) 2DTH|Yv  
{ j3`:;'L  
sFileName = value; >?M:oUVDU  
} jb)z[!FbM  
N&S :=x:$S  
S7wZCQe  
public int getNSplitter() ~n]:f7?I  
{ |Uy hH^  
return nSplitter; %S>lPt  
} w[PW-m^`  
}?*:uf  
|Y/iq9l  
public void setNSplitter(int nCount) 4OCz:t  
{ H) q9.Jg  
nSplitter = nCount; BEPDyy  
} K"Nq_Ddwd  
} R9S7p)B  
Z i7(lG  
0plRsZ}  
/* !Si ZA"  
**Utility.java PhKJ#D Rbr  
*/ g IX"W;  
package NetFox; _}jj>+zA`  
28X)s!W'  
M%&`&{  
public class Utility { ?_\Hv@t;  
}}t"^ms  
Vize0fsD  
public Utility() x"AYt:ewuc  
{ gADt%K2 #Z  
s.zH.q,  
Y0|~]J(B  
} z RvYN  
sS5#Q  
//线程睡眠 e yTYg  
public static void sleep(int nSecond) c~R ElL  
{ N@Slc 0  
try{ ODv)-J  
Thread.sleep(nSecond); s%4)}w;z  
} ( Y/ DMQ  
catch(Exception e) n )`*{uv$  
{ q;kM eE*  
e.printStackTrace (); Htsa<t F  
} T^A:pL1  
} Zpu>T2Tp  
Mv4JF(,S  
//日志 qV iky=/-  
public static void log(String sMsg) +#&2*nY  
{ A FfgGO  
System.err.println(sMsg); &k1Ez  
} Zls4@/\Q  
q%>L/KJ#  
!EpP-bq'*  
public static void log(int sMsg) {R1jysG tD  
{ =9pFb!KX  
System.err.println(sMsg); vj{h*~  
} #exE ~@fy-  
} BIcE3}dS8  
$: Qi9N   
$)7-wCl</  
/* EO'3;mo,  
**TestMethod.java f0wQn09  
*/ sF|<m)Kt{W  
package NetFox; ,qvz:a  
?c>j^}A/N  
.`)ICX  
public class TestMethod { Q`19YX  
[HNGTde&  
kk!}mbA_}  
public TestMethod() x5PQ9Bw,  
{ ///xx/weblogic60b2_win.exe CH9#<?l  
try{  NsJUruN  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )}u.b-Nt.  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @.CPZT  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6"A|)fz  
fileFetch.start(); SrHRpxy  
} dnNc,l&g  
catch(Exception e){e.printStackTrace ();} v5<Ext rV  
3s>& h-E  
~^VcTSY@<L  
} ~9'VP }\  
Q*KEODR8\  
Ko -<4wu  
public static void main(String[] args) ] YQ*mvI]  
{ @p `#y  
new TestMethod(); ld2 \/9+n  
} {kZhje^$vi  
} ,VHvQU  
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