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http断点续传简单实现(java)

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/* LZ\q3 7UV  
**SiteFileFetch.java ];}Wfl  
*/ .v]IJfRH*  
package NetFox; "MxnFeLM#  
import java.io.*; kHk px52  
import java.net.*; ,K>I%_!1  
y6@0O%TDN  
Q0$8j-1I  
public class SiteFileFetch extends Thread { *aXF5S  
>@BnV{ d  
,V'o4]H  
SiteInfoBean siteInfoBean = null; //文件信息Bean rjl`&POqc  
long[] nStartPos; //开始位置 32l3vv.j  
long[] nEndPos; //结束位置 ImCe K  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 v.\*./-i  
long nFileLength; //文件长度 -Bt k 3  
boolean bFirst = true; //是否第一次取文件 3yANv?$a  
boolean bStop = false; //停止标志 -1Jg?cPz k  
File tmpFile; //文件下载的临时信息 +O'3|M  
DataOutputStream output; //输出到文件的输出流 gwNq x"  
z _g~  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) hrmut*<|  
public SiteFileFetch(SiteInfoBean bean) throws IOException 3sc+3-TF  
{ *RT>`,t/  
siteInfoBean = bean; 6~OoFm5  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); bf0+DvIB  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); )Z[ft  
if(tmpFile.exists ()) w^(<N7B3T  
{ ml2_ ]3j!  
bFirst = false; :WC2Ax7$2  
read_nPos(); t4{rb, }W  
} &6DMk-  
else 1h(0IjG8  
{ 3E7ULK  
nStartPos = new long[bean.getNSplitter()]; D@C-5rmq  
nEndPos = new long[bean.getNSplitter()]; yh^!'!I6u[  
} z+x\(/  
vVj  
BW-`t-,E;  
tv>>l%  
} CF&NFSti^  
dL:-Y.?0M  
})uGRvz  
public void run() 9s_vL9u  
{ xrlmKSPa  
//获得文件长度 =nz}XH%=  
//分割文件 >d~WH@o`G  
//实例FileSplitterFetch g"Ljm7  
//启动FileSplitterFetch线程 Gb"r|(!  
//等待子线程返回 *?o{9v5}(  
try{ /`9sPR6e  
if(bFirst) z+ s6)Ad  
{ Q*~LCtrI  
nFileLength = getFileSize(); W egtyO  
if(nFileLength == -1) #btLa\HJ  
{ 0fc/wfv <  
System.err.println("File Length is not known!"); 0?sRDYaX;c  
} aHlcfh9|  
else if(nFileLength == -2) nJbtS#`G4  
{ _4TH4~cY  
System.err.println("File is not access!"); qd+h$ "p  
} Z.d 7U~_  
else ekI2icD  
{ A2^\q>_#  
for(int i=0;i<nStartPos.length;i++) H|,Oswk~-  
{  zG+R5:  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 4!$s}V=6  
} >Wh}f3C  
for(int i=0;i<nEndPos.length-1;i++) U QE qX  
{ vQ<90Z xqB  
nEndPos = nStartPos[i+1]; %509\;el  
} zs%Hb48V   
nEndPos[nEndPos.length-1] = nFileLength; vesJEaw7  
} &-s'BT[PGq  
} ?P4w]a  
Pa(^}n|  
.tkT<o-u<J  
//启动子线程  pnMEB,)  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MzPzqm<  
for(int i=0;i<nStartPos.length;i++) hbU+Usx  
{ r~+\ Y"rM  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |\_^ B  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [qdRUV'  
nStartPos,nEndPos,i); ;g6M%;1-  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *eIJwXE  
fileSplitterFetch.start(); .R)PJc5^  
} x??pBhJH  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 79nG|Yj|\  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1);  ~UyV<  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }YjX3|8zL=  
nEndPos = " + nFileLength); J%V-Q>L  
// fileSplitterFetch[nPos.length-1].start(); dp++%:j  
qZ]pq2G  
"~=mG--I  
//等待子线程结束 IC6gU$e  
//int count = 0; u583_k%  
//是否结束while循环 KQcs3F@t  
boolean breakWhile = false; ,B08i o-  
SaC d0. h  
7uT:b!^f[  
while(!bStop) !l_lo`)  
{ Kh(ZU^{n  
write_nPos(); .U"8mP=&  
Utility.sleep(500); 7~9S 9  
breakWhile = true; ygeDcnvR]  
U`,0]"Qk  
FW) x:2BG  
for(int i=0;i<nStartPos.length;i++) m.px>v-  
{ 9m|kgY# 4  
if(!fileSplitterFetch.bDownOver) p`nPhk,:b  
{ <WjF*x p  
breakWhile = false; Vm5c+;  
break; <cZGxff01  
} k4,BNJt'Z  
} ?6(I V]  
if(breakWhile) UJ0<%^f  
break; Dw=gs{8D  
wUiys/ OVM  
3= DNb+D!  
//count++; Au{<hQ =  
//if(count>4) ^M%uV  
// siteStop(); %@;6^=  
} d}LRl"_n  
w$H^q !(  
H~GQ;PhRx  
System.err.println("文件下载结束!"); A 6OGs/:&  
} Na$Is'F &p  
catch(Exception e){e.printStackTrace ();} b8$gx:aJ>$  
} CSGz3uC2D  
^Y u6w\QM  
nt;haeJ  
//获得文件长度 S{FROC~1R  
public long getFileSize() af#pR&4}   
{ #Y0-BYa^  
int nFileLength = -1; %uJ<M-@r=u  
try{ !lxTX  
URL url = new URL(siteInfoBean.getSSiteURL()); \%/#x V  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0VckocF  
httpConnection.setRequestProperty("User-Agent","NetFox"); pWPIJ>2G:  
A,V\"KU  
BYO"u6  
int responseCode=httpConnection.getResponseCode(); TpmwD{c[\  
if(responseCode>=400) $={:r/R`i  
{ T21ky>8E  
processErrorCode(responseCode); e%4:) IV!;  
return -2; //-2 represent access is error CNr/U*+  
} vo\fUT@k  
}"|"Q7H  
e{X6i^% m_  
String sHeader; c1$ngH0  
u5 {JQO  
>H(i^z/c  
for(int i=1;;i++) nB%;S  
{ D?C)BcN  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aO@ 7O*  
//Utility.log(in.readLine()); %FS$zOsgGK  
sHeader=httpConnection.getHeaderFieldKey(i); eh4gQ^l  
if(sHeader!=null) 28/ ADZ  
{ Zm"{Viv]  
if(sHeader.equals("Content-Length")) %honO@$  
{ 5Xl /L  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NE/m-ILw  
break; "Fy7K#n  
} 0O\SU"bP  
} {r> .G7P6  
else {%VV\qaC  
break; [zL7Q^~  
} f6_];]yP  
} Xcrk;!IB?  
catch(IOException e){e.printStackTrace ();} |J+(:{ }~  
catch(Exception e){e.printStackTrace ();} f;&]:2.j  
bHht d_}  
V?P,&c?84  
Utility.log(nFileLength); ~by]xE1Eg  
a 4=N9X  
<+^6}8-  
return nFileLength; 1iX)d)(b  
} Nru7(ag1~  
?gO8kPg/D  
za:a)U^n  
//保存下载信息(文件指针位置) yC3yij<oR  
private void write_nPos() 2:BF[c`  
{ 9Ro6fjjE  
try{ \k]x;S<a  
output = new DataOutputStream(new FileOutputStream(tmpFile)); %'xb%`t  
output.writeInt(nStartPos.length); :9R=]#uD  
for(int i=0;i<nStartPos.length;i++) *?z0$Kz<,[  
{ 21ppSN >  
// output.writeLong(nPos); cooUE<a  
output.writeLong(fileSplitterFetch.nStartPos);  6\u!E~zy  
output.writeLong(fileSplitterFetch.nEndPos); h)6GaJ=  
} *\wp?s>-t  
output.close(); d{3@h+zL  
} oT{@_U{*J  
catch(IOException e){e.printStackTrace ();} QJ F=UB  
catch(Exception e){e.printStackTrace ();} 1=|7mehL%  
} {^ m(,K_  
YAL=!~6  
277ASCWLkU  
//读取保存的下载信息(文件指针位置) UWZa|I~:J  
private void read_nPos() e/*$^i+S  
{ |.F  
try{ V~T@6S  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J0 k  
int nCount = input.readInt(); :-iMdtm  
nStartPos = new long[nCount]; Ja]?&j  
nEndPos = new long[nCount]; Z1ALq5  
for(int i=0;i<nStartPos.length;i++) kW`r=u  
{ OFGsjYLw  
nStartPos = input.readLong(); 6 4D]Ypx  
nEndPos = input.readLong(); 7_wJpTz  
} T"p(]@Ng  
input.close(); ?\U!huu  
} yJsH=5A  
catch(IOException e){e.printStackTrace ();} &f>eQ S=(  
catch(Exception e){e.printStackTrace ();} l{:a1^[>y  
} 8K;Y2 #  
GyW.2  
3;7q`  
private void processErrorCode(int nErrorCode) dLvJh#`o  
{ < AI;6/  
System.err.println("Error Code : " + nErrorCode); [k[u*5hP|F  
} X53mzs  
4"@GNk~e  
x lsqj`=  
//停止文件下载 6AvHavA^Y  
public void siteStop() R#n%cXc|  
{ R*zO dxY  
bStop = true; !j1[$% =#  
for(int i=0;i<nStartPos.length;i++) ygS L  
fileSplitterFetch.splitterStop(); M wab!Ya  
(f_g7B2&y  
PSRzrv$l  
} !ph" mf$-  
} li] 6Pj,  
//负责部分文件的抓取 =39 ?:VoD  
**FileSplitterFetch.java EQIUSh)M  
*/ `p0ypi3hn  
package NetFox; 2$ !D* <  
wNNB;n` l  
2b=)6H1  
import java.io.*; B51kV0  
import java.net.*; LhzMAW<L4  
RA],lNs  
>r)X:K+I  
public class FileSplitterFetch extends Thread { QC0!p"  
Fl{WAg  
~P-*}q2J  
String sURL; //File URL B/J&l  
long nStartPos; //File Snippet Start Position b@t5`Y-+K  
long nEndPos; //File Snippet End Position IN7<@OS7  
int nThreadID; //Thread's ID xU S]P)R  
boolean bDownOver = false; //Downing is over (X+s-4%  
boolean bStop = false; //Stop identical m ,>  
FileAccessI fileAccessI = null; //File Access interface m7=1%6FN3  
#FYAV%pi  
L{ho*^b  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?$z.K>S5  
{ !r+IXuqV,!  
this.sURL = sURL; S2C]?6cTq  
this.nStartPos = nStart; p T[gdhc  
this.nEndPos = nEnd; "PH6e bm  
nThreadID = id; -6=<#9R  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )9=(|Lp  
} `@`1pOb  
RGD]8 mw  
td{O}\s7D  
public void run() ~%#mK:+  
{ | A:@ &|  
while(nStartPos < nEndPos && !bStop) ]lS@}W\  
{ Q0_>'sEM  
p|XAlia  
8I+d)(:  
try{ K3mA XC,d  
URL url = new URL(sURL); K(T\9J.  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'GJVWpvUU  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ep~wWQh  
String sProperty = "bytes="+nStartPos+"-"; ~2uh'e3  
httpConnection.setRequestProperty("RANGE",sProperty); U5/qf8)yO  
Utility.log(sProperty); >qn/<??  
7ODaX.t->  
-DO&_`kn  
InputStream input = httpConnection.getInputStream(); wH"kk4^  
//logResponseHead(httpConnection); XTqm]  
RbQ <m!A  
LH]CUfUrUE  
byte[] b = new byte[1024]; 49 }{R/:  
int nRead; DFe;4BdC  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TSL9ax4j  
{ 7\/5r.  
nStartPos += fileAccessI.write(b,0,nRead); znZ7*S >6\  
//if(nThreadID == 1) ~# 7wdP  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uCzii o`S  
} Y:x/!-  
V*65b(q)  
AxCI 0  
Utility.log("Thread " + nThreadID + " is over!"); PI|`vC|yy&  
bDownOver = true; VY'Q|[  
//nPos = fileAccessI.write (b,0,nRead); ';RI7)<  
} dEp/dd~(&  
catch(Exception e){e.printStackTrace ();} Jm(ixekp  
} =qoRS0Qa  
} A8?[6^%O|  
~U}Mv{ y  
noA-)  
//打印回应的头信息 .Gb+\E{M  
public void logResponseHead(HttpURLConnection con) *j*Du+  
{ 0jB X5  
for(int i=1;;i++) +nZRi3yu=  
{ iRV ;Fks  
String header=con.getHeaderFieldKey(i); &1)xoZ'\  
if(header!=null) *M~.3$NN  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FWPW/oC  
Utility.log(header+" : "+con.getHeaderField(header)); IlLn4Iw  
else <>4!XPo%J  
break; ;R[&pDx  
} zp=!8Av  
} }++5_Z_  
PDw{R]V+  
BSXdvI1y  
public void splitterStop() C ?H{CP  
{ @?2n]n6  
bStop = true; g0#q"v55  
} )&Z>@S^  
K&pM o.  
dc^Vc{26Z  
} }. %s xw  
;;LuU<,$  
aIGn9:\  
/* _J"mR]I+  
**FileAccess.java &?a.mh/8[[  
*//文件访问(定位,写) boQ)fV"  
package NetFox; rB]W,8~%  
import java.io.*; R "E<8w  
0#|7U_n  
kEK[\f VE  
public class FileAccessI implements Serializable{ INLf#  N  
kfpm=dKL  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %yw=[]Vjze  
RandomAccessFile oSavedFile; 8[\ 79|  
long nPos; O@`J_9  
c2b6B.4  
_:,.yRez  
public FileAccessI() throws IOException 4%bTj,H#  
{ Hptq,~_t  
this("",0);  [y{E  
} ~PUsgL^  
+>E5X4JC  
q0|Z oP  
public FileAccessI(String sName,long nPos) throws IOException z<QIuq  
{ SL*DK.  
oSavedFile = new RandomAccessFile(sName,"rw"); A c:\c7M;  
this.nPos = nPos; *98Ti|  
oSavedFile.seek(nPos); di_gWE  
} lV7IHX1P  
y''0PSfb#  
<lx^aakk!  
public synchronized int write(byte[] b,int nStart,int nLen) 3Wj,}  
{ ~x+Ykq0  
int n = -1; Hs<n^fyf  
try{ e 2*F;.)  
oSavedFile.write(b,nStart,nLen); LV=^jsQ5  
n = nLen; -R@JIe_28f  
} ]S]"`;Wh  
catch(IOException e) q6)p*}-  
{ b3^R,6]x&  
e.printStackTrace (); (6#M9XL  
} -,@bA @&  
=|# w.(3y  
-y<x!61  
return n; rIp'vy S\p  
} gN\*Y  
s;>VeD)*)  
:xN8R^(  
} ;Bnr=' [  
x?>!UqgkY  
(.oaMA"B  
/* [,\i[[<  
**SiteInfoBean.java ?7rD42\8H  
*/ D3]@i&^B  
package NetFox; )T<D6l Lt  
_3KZME  
z qO$  
public class SiteInfoBean { Lkp&;+  
0i _  
b7qnO jC  
private String sSiteURL; //Site's URL Ix4jof6(  
private String sFilePath; //Saved File's Path sVlZNj9i"  
private String sFileName; //Saved File's Name Ku&*`dME  
private int nSplitter; //Count of Splited Downloading File {SHqW5VX  
/9TL&_A-T  
IE@ z@+\(  
public SiteInfoBean() G#g{3}dcK  
{//nSplitter的缺省值为5 rkP4<E-M  
//default value of nSplitter is 5 '@S,V/jy0z  
this("","","",5); HD~jU>}}  
} J,`_,T  
j`+0.Zlq  
1 O- E],  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u,!4vKx  
{ b e_C>v  
sSiteURL= sURL; @?j@yRe  
sFilePath = sPath; )MMhlcNC  
sFileName = sName; <Q\H  
this.nSplitter = nSpiltter; g!.Ut:8L9  
sOjF?bCdO  
Skr iX\p  
} j& <tdORT  
d{iL?>'?^  
+H?<}N*T  
public String getSSiteURL() QQSH +  
{ &s2#1  
return sSiteURL; 0K`ZX&K?W  
} B>ge, }{  
Sn+FV+D  
u% r!?-z  
public void setSSiteURL(String value) nh?9R&  
{ 4*YOFU}l  
sSiteURL = value; L;4[ k;5  
} @\S]]oLn  
@yCW8]  
P7cge  
public String getSFilePath() % i %ew4  
{ %f>X-*}NI-  
return sFilePath; 2z[r@}3  
} n=;';(wR[  
`X3Xz!  
rO5u~"v]  
public void setSFilePath(String value) 1mY+0  
{ 0I(uddG3  
sFilePath = value; ntDRlX  
} %GNUnr$  
5#yJK>a7  
p6B .s_G4  
public String getSFileName() l@~1CMyN  
{ (QA-"9v#i,  
return sFileName; .jLMl*6%:  
} &S9f#Ui  
0zlM.rjEZ  
r.Y*{!t  
public void setSFileName(String value) T$#FAEz  
{ =I+l=;05Rd  
sFileName = value; l7!U),x%/U  
} (ra:?B  
3"HGEUqA  
HKq2Js  
public int getNSplitter() 97['VOh0  
{ J(3gT }z-  
return nSplitter; T_(qN;_  
} }C_G0'"F  
}R7sj  
\.K\YAM<  
public void setNSplitter(int nCount) eL]{#WL  
{ RPz!UMQSD  
nSplitter = nCount; ;"d?_{>7  
} ~uP r]#  
} 2U=/<3;u  
^#<: <X6  
g,A.Y,})  
/* [K"U_b}w  
**Utility.java e6tH/`Uln  
*/ N*_/@qM> a  
package NetFox; z Y$X|= f  
+Q@/F~1@6@  
EX+={U|ua$  
public class Utility { x`};{oz;  
'd|Q4RE+W  
[0mFy) 6  
public Utility() ;zfQ3$@9  
{ < fojX\}3  
2LhfXBWf  
pDLu+ }@  
} c n\k`8  
f_Wkg)g  
//线程睡眠 +YGw4{\EL  
public static void sleep(int nSecond) GnSgO-$"  
{ { r< (t#  
try{ W\ 1bE(AwZ  
Thread.sleep(nSecond); o<C]+Nt,@  
} |_hioMVz  
catch(Exception e) ]7XkijNb  
{ lpM>}0v   
e.printStackTrace (); w^:V."}-$  
} oTplxF1  
} ``2QOu 1  
_IQU<Za  
//日志 fPh}l  
public static void log(String sMsg) F20wf1^  
{ h"RP>fZt  
System.err.println(sMsg); zIAu3  
} EI?d(K  
X/- W8  
fD3jwPL  
public static void log(int sMsg) ,ZzB#\  
{ t%]^5<+X58  
System.err.println(sMsg); rL!_&|  
} 78^UgO/  
} []2$rJZD9  
l0:e=q2Ax  
EPE!V>  
/* E3FW*UNg[y  
**TestMethod.java L|C1C cP  
*/ gL[1wM%?  
package NetFox; XEvGhy#  
<WQ<<s@#pb  
avHD'zU}N  
public class TestMethod { 2yEO=SN,(  
Vid{6?7kh  
tdw\Di#m  
public TestMethod() hX>VVeIZ  
{ ///xx/weblogic60b2_win.exe 4."o.:8x  
try{ !i~x"1  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g~ppPAH  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3$96+A^M*  
SiteFileFetch fileFetch = new SiteFileFetch(bean); )JY_eG&2Dx  
fileFetch.start(); (dLE<\E  
} Cu ['&_@  
catch(Exception e){e.printStackTrace ();} +qh< Fj>  
!BvTJ-e)F  
,E/Y@sajn+  
} uK4'n+_>\  
JA SR  
ABq{<2iYN  
public static void main(String[] args) T/Wm S?  
{ 7 BnenHD  
new TestMethod(); 0]h8)EW  
} $p}~,Kp/  
} $$bTd3N+  
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