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http断点续传简单实现(java)

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/* +tv"j;z  
**SiteFileFetch.java e[.JS6  
*/ 8ao>]5Rs3  
package NetFox; ztaSIMZ  
import java.io.*; ^ Mq8jw(2  
import java.net.*; P)06<n1">Z  
%T~LK=m  
+?C7(-U>  
public class SiteFileFetch extends Thread { 8wzQr2:  
0F[+rh"x  
^cI RP  
SiteInfoBean siteInfoBean = null; //文件信息Bean @9h6D<?  
long[] nStartPos; //开始位置 [F^j(qTR  
long[] nEndPos; //结束位置 lUM-~  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 I oC}0C7  
long nFileLength; //文件长度 _I #a `G  
boolean bFirst = true; //是否第一次取文件 yJHFo[wGMJ  
boolean bStop = false; //停止标志 (!diPwcv  
File tmpFile; //文件下载的临时信息 D~f[Rg  
DataOutputStream output; //输出到文件的输出流 -Rr Qv(  
M_#^zo "x  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) S(5&%}QFQ  
public SiteFileFetch(SiteInfoBean bean) throws IOException f:/"OCig  
{  @@+BPLl  
siteInfoBean = bean; )9V8&,  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); C,dRdEB>  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); @t,Y< )U  
if(tmpFile.exists ()) ?~rz'Pu~  
{ Ccy0!re  
bFirst = false; pm'i4!mY<P  
read_nPos(); U$6(@&P!  
} >Te h ?P  
else [kPF Jf  
{ kBJx`tjtp  
nStartPos = new long[bean.getNSplitter()]; )E=~ _`XO  
nEndPos = new long[bean.getNSplitter()]; oJor ]QYK  
} JA6#qlylL  
t;)`+K#1:  
)ZDqj  
1H7 bPl|  
} 690;\O '  
:3By7BZgj  
K}Rq<z W  
public void run() iVf8M$!m  
{ 9':MD0P/M  
//获得文件长度 #~;:i  
//分割文件 ;Qdw$NuW  
//实例FileSplitterFetch Te&5IB-  
//启动FileSplitterFetch线程 ~#9(Q  
//等待子线程返回 !l#n.Fx&3  
try{ FKkL%:?  
if(bFirst) ,Q>wcE6v  
{ fdzaM&  
nFileLength = getFileSize(); 1<&nHFJ;[  
if(nFileLength == -1) ZD`0(CkXb  
{ 0^zp*u  
System.err.println("File Length is not known!"); G}gmkp]z  
} H!uq5` j0K  
else if(nFileLength == -2) sWX\/Iyy2p  
{ Nmu=p~f}3`  
System.err.println("File is not access!"); ,~qjL|9  
} )W$@phY(I  
else $|!@$Aj  
{ 9i/VvW  
for(int i=0;i<nStartPos.length;i++) {&s.*5  
{ ?M@ff0  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); @N+6qO}  
} XiN@$  
for(int i=0;i<nEndPos.length-1;i++) _6{XqvWqb  
{ {x/)S*:Z  
nEndPos = nStartPos[i+1]; J+0T8 ?A  
} $ 2PpG|q  
nEndPos[nEndPos.length-1] = nFileLength; !6DH6<HC  
} !ZTBiC5R  
} 3q:>NB<  
Bq#B+JwX  
>r5s>A[YC  
//启动子线程  B/ACU  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E3,Nc`'m9  
for(int i=0;i<nStartPos.length;i++) f|-%.,  
{ uUI@!)@2  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PvqG5-L~W  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ""u>5f  
nStartPos,nEndPos,i); kJG0X%+w  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0N4+6k|  
fileSplitterFetch.start(); m<| *  
} y?yWM8  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @DA.$zn&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =/L;}m)7  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $VyH2+ jC  
nEndPos = " + nFileLength); V [r1bF  
// fileSplitterFetch[nPos.length-1].start(); Pvu*Y0_p  
CWS&f g%o{  
ca!DZ%y  
//等待子线程结束 4Q n5Mr@<  
//int count = 0; 2g:V_%  
//是否结束while循环 o<nkK+=Afm  
boolean breakWhile = false; >.f'_2#Z&  
v* /}s :a  
`%A>{A"  
while(!bStop) y9)Rl)7-:  
{ -|nHwSrCZ/  
write_nPos(); Iji9N!Yx  
Utility.sleep(500); Q=Y1kcTOn  
breakWhile = true; -/ h'uG  
!Xf7RT  
?PST.+l  
for(int i=0;i<nStartPos.length;i++) 5t-dvYgU  
{ -x0VvkHu  
if(!fileSplitterFetch.bDownOver) .0f6b  
{ BP`'1Ns  
breakWhile = false; Fy-N U  
break; OVgx2_F  
} 4J6,_8`U  
} %$H~  
if(breakWhile) j9]H~:g$d  
break; O[/l';i  
|>L|7>J{<d  
E{B=%ZNnm  
//count++; |$aTJ9 Iq:  
//if(count>4) >,s.!vpK  
// siteStop(); ;^Hg\a  
} &$+nuUA  
dE0 p>4F  
WyD L ah^/  
System.err.println("文件下载结束!"); n%1I}?$fO  
} i%eq!q  
catch(Exception e){e.printStackTrace ();} `U[s d*C"  
} ?ta(`+"  
ej9|Y5D"S  
X9oxni#  
//获得文件长度 {#X]D~;s+  
public long getFileSize() .|Zt&5osI  
{ A,'JmF$d  
int nFileLength = -1; B>"O~ gZ{#  
try{ 1hnw+T<<W  
URL url = new URL(siteInfoBean.getSSiteURL()); xU_Dg56z'&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3iC$ "9!p  
httpConnection.setRequestProperty("User-Agent","NetFox"); $X%'je  
8#&axg?a  
#\X="' /  
int responseCode=httpConnection.getResponseCode(); g<&n V>wF  
if(responseCode>=400) -p\uW 0XA  
{ N! N>/9  
processErrorCode(responseCode); +{F2hEYP  
return -2; //-2 represent access is error vPbmQh ex  
} 3 2MdDa  
bQFMg41*w7  
mz kv/  
String sHeader; mcB8xE  
/9..hEq^  
}g\1JSJ%H  
for(int i=1;;i++) drc]"6 k  
{ 7-u['nFJ  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); quEP"  
//Utility.log(in.readLine()); G^Q8B^Lg  
sHeader=httpConnection.getHeaderFieldKey(i); C_~hX G  
if(sHeader!=null) 8Q2qroT  
{ ':jsCeSB  
if(sHeader.equals("Content-Length")) @CJ`T&  
{ R<GnPN:c  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G$)f5_]7{  
break; :s5wFumD  
} tUPdq0%t[  
} >|S&@<  
else (+^z9p7/!  
break; C%l+<wpXO  
} E0o?rgfdq  
} 9< $n'g  
catch(IOException e){e.printStackTrace ();} 7eyVm;LQD  
catch(Exception e){e.printStackTrace ();} 6~@S,i1  
fi.[a8w:W  
QSxR@hC  
Utility.log(nFileLength); /\0 rRT  
WK<:(vu.  
6pCQP c*A  
return nFileLength; }KZt7)  
} |)vC^=N{+  
^[]@dk9  
~dFdO7  
//保存下载信息(文件指针位置) d@?++z  
private void write_nPos() #OT8_D  
{ {r,MRZaa  
try{ lPywr TG0  
output = new DataOutputStream(new FileOutputStream(tmpFile)); [m9Iz!E  
output.writeInt(nStartPos.length); %Ct^{k~1  
for(int i=0;i<nStartPos.length;i++) f*IC ZM  
{ Z&VH7gi  
// output.writeLong(nPos); F^/1 u  
output.writeLong(fileSplitterFetch.nStartPos); e M$NVpS3  
output.writeLong(fileSplitterFetch.nEndPos); E9"P~ nz  
} +nj 2  
output.close(); 3?+CP-T-j  
} 6(5YvT  
catch(IOException e){e.printStackTrace ();} N#Y|MfLc  
catch(Exception e){e.printStackTrace ();} `3CdW  
} 4N- T=Ig  
OrJuE[R.  
>Yf)]e-  
//读取保存的下载信息(文件指针位置) G'M;]R9EP  
private void read_nPos() (5Z*m<]c  
{ ~7$4w# of0  
try{ _,?<r&>v6  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8NJxtT~0c~  
int nCount = input.readInt(); *@zh  
nStartPos = new long[nCount]; +[R,wsG  
nEndPos = new long[nCount]; "^UJC-  
for(int i=0;i<nStartPos.length;i++) FZ0wtS2  
{ ruKm_j#J  
nStartPos = input.readLong(); 8`{)1.d5[  
nEndPos = input.readLong(); 'kC,pN{->  
} N-9Vx#i  
input.close(); MN.h,^b  
} Ddr.kXIpo  
catch(IOException e){e.printStackTrace ();} ,_$}>MY;  
catch(Exception e){e.printStackTrace ();}  4.7 PL  
} y_7lSo8<  
26&$vgO~:  
oE H""Bd  
private void processErrorCode(int nErrorCode) UCz\SZ{za  
{ }^@Q9<P^E  
System.err.println("Error Code : " + nErrorCode); iaAj|:  
} nsM=n}$5x  
iiw\  
y$Rr,]L  
//停止文件下载 $Sx(vq6(  
public void siteStop() /~O>He  
{ `Pcbc\"*y  
bStop = true; 8nj^x?bn  
for(int i=0;i<nStartPos.length;i++) UK7pQt}9  
fileSplitterFetch.splitterStop(); p" ;5J+?(  
'BiR ,M$mY  
=Lc!L !(,b  
} Hrk]6*  
} OtVRhR3>  
//负责部分文件的抓取 ]27  
**FileSplitterFetch.java )43\qIu\  
*/ Y_gMoo  
package NetFox; @BfJb[A#  
:< d.  
I0qS x{K  
import java.io.*; 0'QX*xfa>  
import java.net.*; d5z=fH9  
2&,jO+BqE@  
tpY]Mz[J  
public class FileSplitterFetch extends Thread { v><c@a=[  
:]rb}1nLB  
`k.Tfdu)K  
String sURL; //File URL t4P`#,:8  
long nStartPos; //File Snippet Start Position e2><Y<  
long nEndPos; //File Snippet End Position GGQ%/i]:  
int nThreadID; //Thread's ID %6%~`((4  
boolean bDownOver = false; //Downing is over Pss$[ %  
boolean bStop = false; //Stop identical b4R;#rm  
FileAccessI fileAccessI = null; //File Access interface 3OlXi9>3  
z]%c6ty  
mM$|cge"  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^5D%)@~  
{ ..K@'*u  
this.sURL = sURL; Xt .ca,`U  
this.nStartPos = nStart; #hZ`r5GvTj  
this.nEndPos = nEnd; 7G \a5  
nThreadID = id; p=jpk@RX  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #lY_XV.  
} VRs|";  
[pRRBMho  
1`Ig A0V`"  
public void run() Ct<]('Hm(  
{ KL<,avC/  
while(nStartPos < nEndPos && !bStop) Ym8 V)  
{ D^Gs_z$['  
l"rX'g?  
:u9OD` D  
try{ gr^T L1(  
URL url = new URL(sURL); JE *d-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bl3?C  
httpConnection.setRequestProperty("User-Agent","NetFox"); f|'0FI  
String sProperty = "bytes="+nStartPos+"-"; Vm*E^ v  
httpConnection.setRequestProperty("RANGE",sProperty); K0usBA  
Utility.log(sProperty); )4e8LO  
B6yTD7  
11((b  
InputStream input = httpConnection.getInputStream(); qN"Q3mU^h*  
//logResponseHead(httpConnection); "OO)m](w  
jAcrXB*  
A`:a T{j  
byte[] b = new byte[1024]; W5Uw=!LdEY  
int nRead; =o5|W'>`  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `PUGg[Zx^  
{ UasU/Q <   
nStartPos += fileAccessI.write(b,0,nRead); W>j@E|m$  
//if(nThreadID == 1) ]<*-pRN  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,x=S)t  
} -hY@r 7y  
|kGQ~:k+P  
aJ"m`5]=%  
Utility.log("Thread " + nThreadID + " is over!"); *N&~Uq^  
bDownOver = true; % aqP{mOO  
//nPos = fileAccessI.write (b,0,nRead); &"?S0S>r!  
} c[>xM3=e^q  
catch(Exception e){e.printStackTrace ();} H:F'5Zt  
} %6W%-`  
} bs&>QsI?j  
8Drz i!}  
CUN1.i<pk8  
//打印回应的头信息 1N}vz(0"  
public void logResponseHead(HttpURLConnection con) )`BKEa f  
{ p/U{*i ]t  
for(int i=1;;i++) ~Z~V:~  
{ mIZ6[ ?  
String header=con.getHeaderFieldKey(i); :2.<JUDM  
if(header!=null) 0T7t.  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Rc vp@  
Utility.log(header+" : "+con.getHeaderField(header)); ij,Rq`}l  
else #,9s\T  
break; \c}pzBFd  
} aH?+^f"D  
} >r3SF3XMq  
_CMNmmp`e  
7Fx0#cS"\  
public void splitterStop() Yi j^hs@eV  
{ hXh nJ  
bStop = true; DF>3)oTF  
} 4a=QTq0p  
aka)#0l .  
FP'-=zgc  
} 7^7Jh&b)/  
#U(kK(uO  
hv`I`[/J  
/* 63i&<  
**FileAccess.java 3$_JNF`  
*//文件访问(定位,写) dmWCNeja.  
package NetFox; aJ QzM  
import java.io.*; fC".K Yjp  
DNr*|A2<  
<aLS4  
public class FileAccessI implements Serializable{ unih"};ou  
7`f%?xVn0  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GC~nr-O  
RandomAccessFile oSavedFile; _=cU2  
long nPos; jV[;e15+  
8iTB  
!FwNq'Q8$  
public FileAccessI() throws IOException 4f&"1:  
{ ? G`6}NP  
this("",0); )$h!lAo  
} $J):yhFs e  
)8!*,e=4  
l8khu)\n4R  
public FileAccessI(String sName,long nPos) throws IOException la}cGZ; p.  
{ f^ja2.*%?  
oSavedFile = new RandomAccessFile(sName,"rw"); a^8PB|G  
this.nPos = nPos; '55G:r39  
oSavedFile.seek(nPos); I~;w Q  
} wn;)La  
2M*i'K;;)P  
58d[>0Xa[g  
public synchronized int write(byte[] b,int nStart,int nLen) \wD L oR  
{ r1TdjnP,2^  
int n = -1; H,c`=Ii3  
try{ mPhu#oK'f  
oSavedFile.write(b,nStart,nLen); K9-9 c"cz  
n = nLen; Cv@)tb  
} n.rn+nuwv  
catch(IOException e) nEUUD3a  
{ SK#&%Yk  
e.printStackTrace (); v[2&0&!K#  
} wBvVY3VQ^  
=P%&]5ts  
q|:wzdmNZ  
return n; $H)Q UFyC  
} t.dr<  
|dz"uIrT  
X 5\xq+Ih  
} x0b=r!Duu  
zO---}[9a  
tXqX[Td`0g  
/* 2n$Wey[  
**SiteInfoBean.java peF)U !`D  
*/ 1yZA_x15:  
package NetFox; L$ i:~6  
*:Rs\QH   
[}M!ez  
public class SiteInfoBean { q-+:1E  
$4^SWT.  
%ioVNbrR7  
private String sSiteURL; //Site's URL S@Rd>4  
private String sFilePath; //Saved File's Path KzP{bK5/  
private String sFileName; //Saved File's Name -|Zzs4bx  
private int nSplitter; //Count of Splited Downloading File ALy7D*Z]w  
/`l;u 7RD  
}W'4(V;:  
public SiteInfoBean() 2l O(f+  
{//nSplitter的缺省值为5 ^86M 94k  
//default value of nSplitter is 5 f9 \$,7F  
this("","","",5); YrJUs]A  
} !:m.-TE  
aG83@ABx  
"a= Hr4C*r  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "p*'HQ  
{ tfN[-3)Z  
sSiteURL= sURL; p20JU zy  
sFilePath = sPath; Scx!h.\5  
sFileName = sName; 'Y#'ozSQv  
this.nSplitter = nSpiltter; m$_b\^we  
e`S\-t?Z  
v2E<~/|  
} -iS^VzI|I  
tj'~RQvO  
\yu7,v  
public String getSSiteURL() -2; 6Pwmv  
{ 6^WNwe\  
return sSiteURL; bY2R/FNL=  
} vUVFW'-  
y^,QM[&  
'.1P\>x!]  
public void setSSiteURL(String value) 4"k&9+>  
{ ~f(5l.  
sSiteURL = value; `hZh}K^  
} L7Hv)  
H7GI`3o  
ZX` \so,&,  
public String getSFilePath() DH yv^  
{ 2t9UJu4  
return sFilePath; $Yt|XT+!&  
} @t~y9UfF  
7;o:r$08&}  
S )rr  
public void setSFilePath(String value) 60vmjmXl  
{ E<Zf!!3  
sFilePath = value; jkx>o?s)z  
} jel:oy|_  
Ig t*8px  
X'jyR:ut#  
public String getSFileName() <@"rI>=  
{ %*}rLn"?  
return sFileName; Yr/$92(  
} T2MC`s|`  
7%i'F=LzT  
hqvhnqQk  
public void setSFileName(String value) V!+iq*Z|=  
{ 3"7Q[9Oj  
sFileName = value; ?!P0UTe~  
} G;}WZy  
hHN[K  
L@{'J  
public int getNSplitter() s|e.mZk/  
{ 3e&+[j  
return nSplitter; <rj'xv  
} 7DJEx~"!2-  
5[Vr {^)  
SK\@w9#&$  
public void setNSplitter(int nCount) OUi;f_*[r  
{ U L $!  
nSplitter = nCount; UeO/<ml3>J  
} VKDOM0{V  
} P}}G9^  
d\JaYizp  
\{ @m  
/* Wp>t\S~N  
**Utility.java 'vd&r@N  
*/ |@u2/U9  
package NetFox; {&n- @$?  
zsXgpnlHT  
Pp-N2t86#2  
public class Utility { 3p=Xv%xd  
E:x@O8F  
g:M;S"U3*Y  
public Utility() K<e #y!  
{ yMz#e0k  
R%WY!I8C  
fWmc$r5n](  
} ,2fi`9=\  
wuH*a3(  
//线程睡眠 +Ww] %`_  
public static void sleep(int nSecond) MW 7~=T  
{ * @4@eQF  
try{ -`PziG l@<  
Thread.sleep(nSecond); H%O\4V2s  
} Y1-dpML  
catch(Exception e) [7I bT:ph  
{ [f_^B U&  
e.printStackTrace (); 1?Y>Xz  
} )XDBK* !  
} YRlfU5  
Ic2?1<IZA  
//日志 r E+B}O  
public static void log(String sMsg) ;qgo=  
{ 2R&\qZ<  
System.err.println(sMsg); 7#R)+  
} l;iU9<~  
r%.k,FzGZY  
0V1GX~2  
public static void log(int sMsg) Mk}T  
{ 7 ~~ug  
System.err.println(sMsg); _"1RidhH  
} [<#j K}g  
} Op%OQ14$  
xJCx zJ  
:*}Q/]N  
/* =x8[%+  
**TestMethod.java 61S;M8tNv  
*/ Y"mFUW4  
package NetFox; Keh=>K)T  
>5 -1?vi  
iwK.*07+  
public class TestMethod { <gF]9%2E  
k_7m[o  
;7P '>j1?U  
public TestMethod() )dkU4]  
{ ///xx/weblogic60b2_win.exe VmqJMU>.  
try{ qdix@ @  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CeYhn\m5K0  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4-yK!LR  
SiteFileFetch fileFetch = new SiteFileFetch(bean); CVfV    
fileFetch.start(); e34>q:#5l  
} :0r,.)  
catch(Exception e){e.printStackTrace ();} e=0]8l>\V  
%y RGN  
XRV]u|w=g  
} CPOH qK`k  
XQy`5iv  
i(j/C  
public static void main(String[] args) ]{1{XIF  
{ `MU~N_  
new TestMethod(); $,}jz.R@  
} R(wUu#n$  
} OXEEpoU?V  
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