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http断点续传简单实现(java)

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/* `%5~>vPS  
**SiteFileFetch.java eGEeWJ}[$  
*/ k O8W>  
package NetFox; Eg/=VBtc  
import java.io.*; %1jlXa  
import java.net.*; ` yXJaTbo  
% a9C]?  
'(S@9%,aK1  
public class SiteFileFetch extends Thread { tAxS1<T4  
FKVf_Ncf%  
kH9fK80  
SiteInfoBean siteInfoBean = null; //文件信息Bean !#' y#  
long[] nStartPos; //开始位置 U5f<4I  
long[] nEndPos; //结束位置 'UN 'gXny  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 )V6<'>1WZ  
long nFileLength; //文件长度 w<54mGMOLr  
boolean bFirst = true; //是否第一次取文件 @*s7~:VQ  
boolean bStop = false; //停止标志 '_`O&rbT  
File tmpFile; //文件下载的临时信息 YH .+(tNv  
DataOutputStream output; //输出到文件的输出流 rF>7 >wq  
$SAk|  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 8<w8"B.i  
public SiteFileFetch(SiteInfoBean bean) throws IOException `VzjXJw  
{ !JOM+P:  
siteInfoBean = bean; 5N'Z"C0  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); B+w< 0No  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); iAWd 9x  
if(tmpFile.exists ()) F ~O}@e{  
{ d_r1 }+ao  
bFirst = false; ' 6#en9{L  
read_nPos(); }X;LR\^u[f  
} $RJpn]d j  
else h+<F,0  
{ \A'tV/YAd  
nStartPos = new long[bean.getNSplitter()]; {WYHT6Z  
nEndPos = new long[bean.getNSplitter()]; F\"`^`(O  
} tI-u@ g  
A['0~tOP  
^]A,Q%1q^  
O,+ZD^  
} #rs]5tx([  
0wlKBwf`J  
74u_YA<"  
public void run() iXJ3B&x  
{ kbHfdA  
//获得文件长度 2 &+Nr+P  
//分割文件 E2Jmo5yJR  
//实例FileSplitterFetch UW?(-_8  
//启动FileSplitterFetch线程 FO/ [7ZH  
//等待子线程返回 $QB~ x{v@n  
try{ c@xQ2&i  
if(bFirst) &P,z$H{o@  
{ w$2Z7S  
nFileLength = getFileSize(); 3{j&J-  
if(nFileLength == -1) E#L"*vh  
{ R3`h$`G  
System.err.println("File Length is not known!"); 4U1!SR]s  
} " Om4P|  
else if(nFileLength == -2) |'R^\M Q  
{ S# 9EBw7  
System.err.println("File is not access!"); %JsCw8C6?  
} $0OWPC1  
else -3)]IA  
{ e~+VN4D&b>  
for(int i=0;i<nStartPos.length;i++) `7))[._  
{ eInx\/  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); `]q>A']Dl  
} t;?TXAA  
for(int i=0;i<nEndPos.length-1;i++) {}W9m)I  
{ CI~P3"`]  
nEndPos = nStartPos[i+1]; ,8vqzI  
} P`$"B0B)  
nEndPos[nEndPos.length-1] = nFileLength; 3S97hn{|=  
} .-[d6Pnw  
} 06dk K )`  
B"903 g 1  
ycr\vn t  
//启动子线程 F*bmV>Qq  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N!u(G  
for(int i=0;i<nStartPos.length;i++) IQ`#M~:  
{ fF"\$Ny  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aUBGp: (  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 64hl0'67y  
nStartPos,nEndPos,i); z'(][SB  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \U0p?wdr:  
fileSplitterFetch.start(); k$u/6lw]IB  
} C]xKdPQj%  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \"X<\3z2  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )<vU F]e~  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J'%  
nEndPos = " + nFileLength); Buue][[  
// fileSplitterFetch[nPos.length-1].start(); n&`=.[+A  
Rqk;!N  
{}#W~1`  
//等待子线程结束 )Yc jx~   
//int count = 0; TCC([  
//是否结束while循环 QNk\y@yKw  
boolean breakWhile = false; C|@6rr9TA  
{5$.:Y  
.sO.Y<- fl  
while(!bStop) 2}ttC m  
{ 78iu<L+If  
write_nPos(); Yb~[XS |p  
Utility.sleep(500); ?_!} lg  
breakWhile = true; ";&5@H|  
aMxg6\8  
IC1oW)  
for(int i=0;i<nStartPos.length;i++) W[dK{?RB  
{ /MErS< 6  
if(!fileSplitterFetch.bDownOver) OF4iGFw  
{ tqnvC UIE  
breakWhile = false; :$>Co\D  
break; 7V^\fh5~  
} *kliI]B F]  
} fO;#;p.  
if(breakWhile) L=ala1{O  
break; l f<?k  
jO|D# nC  
GkhaB(btk'  
//count++; 8f""@TTp  
//if(count>4) i #uc  
// siteStop(); gJkk0wok C  
} EH*Lw c  
cTU%=/gbc<  
r34q9NFT5  
System.err.println("文件下载结束!"); O?6ph4'  
} D4@'C4kL  
catch(Exception e){e.printStackTrace ();} +A 4};]W|  
} (1t b  
i'[o,dbE  
z'FpP  
//获得文件长度 l7+[Zn/v *  
public long getFileSize() o=&tT,z  
{ TJ&Z/k3-  
int nFileLength = -1; 8?YWE62  
try{ {^Y0kvnd  
URL url = new URL(siteInfoBean.getSSiteURL()); 9kpCn.rJ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }i)^?@  
httpConnection.setRequestProperty("User-Agent","NetFox"); ceW,A`J  
3NLC~CJ  
L.cGt"{  
int responseCode=httpConnection.getResponseCode(); jm~qD T,  
if(responseCode>=400) /2<1/[#  
{ UBgheu  
processErrorCode(responseCode); L~WC9xguDl  
return -2; //-2 represent access is error 12Lc$\3P  
} +d$l1j  
-0 e&>H%  
=;) M+"  
String sHeader; lZt{L0  
NoR=:Q 9e  
fsA-}Qc  
for(int i=1;;i++) B.J_(V+  
{ }'"4q  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $bGe1\  
//Utility.log(in.readLine()); Fz3QSr7FU  
sHeader=httpConnection.getHeaderFieldKey(i); FL,av>mV  
if(sHeader!=null) zv Dg1p  
{ 9b8kRz[ c  
if(sHeader.equals("Content-Length")) T!iRg=<bz  
{ A`H&" A  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "EE=j$8u+  
break; $69ef[b  
} GC<zL }  
} 8|*=p4_fn  
else M_ GN3  
break; ,.g9HO/R1  
} zRz7*o&l  
} @S-p[u  
catch(IOException e){e.printStackTrace ();} kY$vPHZpN  
catch(Exception e){e.printStackTrace ();} +FYQ7UE  
0Xke26ga  
dV:vM9+x  
Utility.log(nFileLength); M.[A%_|P  
#Q6.r.3@x  
A18&9gY  
return nFileLength; t!u{sr{j=  
} G OzV#  
h/AL `$  
6{qI  
//保存下载信息(文件指针位置) 5W(S~}  
private void write_nPos() !alO,P%>r  
{ Y(` # J[  
try{ }+" N '  
output = new DataOutputStream(new FileOutputStream(tmpFile)); .QaHE`e{  
output.writeInt(nStartPos.length); !OO{qw(*g  
for(int i=0;i<nStartPos.length;i++) 8%Wg;:DZx  
{ M[Kk43;QY!  
// output.writeLong(nPos); dWCUZ,6}  
output.writeLong(fileSplitterFetch.nStartPos); y*AB=d^  
output.writeLong(fileSplitterFetch.nEndPos); 3=SN;cn  
} 5GwXZ;(G  
output.close(); ,z*-93H1  
} /{j")  
catch(IOException e){e.printStackTrace ();} UB4M=R|  
catch(Exception e){e.printStackTrace ();} z@_ 9.n]  
} *>ilT5q  
y'a(>s(  
WC?}a^ 8  
//读取保存的下载信息(文件指针位置) !JkH$~  
private void read_nPos() 0UHX Li47Y  
{ nhUL{ER  
try{ F$;vPAxbK"  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )bM #s">Y  
int nCount = input.readInt(); }iK_7g`yKa  
nStartPos = new long[nCount]; vfh0aW-O  
nEndPos = new long[nCount]; !Gphs`YI  
for(int i=0;i<nStartPos.length;i++) `wyX)6A|bt  
{ zeXMi:X  
nStartPos = input.readLong(); ^aW?0qsH  
nEndPos = input.readLong(); %o~w  
} %/^k r ZD  
input.close(); bwo{ Lw~  
} Cw=wU/)  
catch(IOException e){e.printStackTrace ();} ic"n*SZa  
catch(Exception e){e.printStackTrace ();} ) LA^j|Y}  
} sF/X#GG-  
4-?'gN_  
a-`OE"  
private void processErrorCode(int nErrorCode) pY3N7&m\:  
{ 0P5!fXs*  
System.err.println("Error Code : " + nErrorCode); gAx8r-` `  
} rQncW~  
wGqQR)a  
H3#xBn>9  
//停止文件下载 O\5*p=v  
public void siteStop() /f_c?|  
{ =,aWO7Pz  
bStop = true; R|Oy/RGY$  
for(int i=0;i<nStartPos.length;i++) LNp%]*h  
fileSplitterFetch.splitterStop(); iwHy!Vi-5  
brQkVt_)EE  
/nK)esB1L  
} ,RkL|'1l  
} ~IHjj1s  
//负责部分文件的抓取 "EoC7 1  
**FileSplitterFetch.java X^tVq..0  
*/ hIj[#M&6  
package NetFox; XFeeNcqF  
XA[G F6W,Y  
q\qV~G`  
import java.io.*; XUD/\MoV  
import java.net.*; ~&/|J)}  
&FWPb#  
x M1>kbo|  
public class FileSplitterFetch extends Thread { n'/w(o$&  
7Q<uk[d0  
VV(>e@Bc4  
String sURL; //File URL H=vrF-#  
long nStartPos; //File Snippet Start Position c<V.\y0x  
long nEndPos; //File Snippet End Position _tfZg /+)  
int nThreadID; //Thread's ID o7feH 6Sh  
boolean bDownOver = false; //Downing is over S9Fg0E+J  
boolean bStop = false; //Stop identical U.oxLbJ`  
FileAccessI fileAccessI = null; //File Access interface @:@0}]%z9  
'3>kDH+  
^4LkKYMS  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,jBd3GdlZ  
{ khl(9R4a  
this.sURL = sURL; {xw*H<"f<  
this.nStartPos = nStart; k]<  
this.nEndPos = nEnd; }>JFO:v&  
nThreadID = id; y2V9!  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0s = h*"[  
} d\`A ^  
4#uWj ?u  
#&.& Uu$  
public void run() (Rvke!"B  
{ (NUk{MTX  
while(nStartPos < nEndPos && !bStop) cL&V2I5O  
{ I)ub='+&;  
lgZ3=h  
Lj"~6l`)  
try{ sXI_!)H  
URL url = new URL(sURL); rE"`q1b#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @v9 PI/c  
httpConnection.setRequestProperty("User-Agent","NetFox"); >Fm}s,  
String sProperty = "bytes="+nStartPos+"-"; *=L3bBu?  
httpConnection.setRequestProperty("RANGE",sProperty); aG?ko*A;  
Utility.log(sProperty); Wy%q9x]}  
4NL Tt K  
vq *N  
InputStream input = httpConnection.getInputStream(); 2q J}5  
//logResponseHead(httpConnection); Qi|jL*mj&  
Cz x U @  
vV1F|  
byte[] b = new byte[1024]; 9Y 1&SEsNX  
int nRead; `G\uTCpk  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ahkSEE{  
{ k,M%/AXd  
nStartPos += fileAccessI.write(b,0,nRead); T#^   
//if(nThreadID == 1) < pI2}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D;)Tm|XizW  
} $j^Jj  
eX 9{wb(  
go/]+vD  
Utility.log("Thread " + nThreadID + " is over!"); >`p`^:  
bDownOver = true; <3z]d?u  
//nPos = fileAccessI.write (b,0,nRead); p~I+ZYWF'  
} [AQ6ads)  
catch(Exception e){e.printStackTrace ();} `pzp(\lc  
} _{&znXf>?6  
} =)m2u2c M  
A1@tp/L=o  
STs~GOm-  
//打印回应的头信息 J&S$F:HM  
public void logResponseHead(HttpURLConnection con) ?U~C= F?K  
{ bT}P":*y  
for(int i=1;;i++) LF <fp&C)h  
{ aOfL;I  
String header=con.getHeaderFieldKey(i); T5NO}bz  
if(header!=null) }kI-UEn$EP  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?8. $A2(Xw  
Utility.log(header+" : "+con.getHeaderField(header)); {bL6%._C  
else S*],18z?  
break; q=ZLSBZ  
} ji<b#YO4  
} 0/S|P1!b  
,rc5r3  
WM NcPHcj  
public void splitterStop() vb)Z&V6(  
{ vL@N21u  
bStop = true; {<iIL3\mC  
} MPA<?  
r]Bwp i%  
] o tjoM  
} jI(~\`  
<",4O  
{NXc<0a(  
/* f:\jPkf'  
**FileAccess.java .2/(G{}U  
*//文件访问(定位,写) LEvdPG$)  
package NetFox; AZt~ \qf  
import java.io.*; &Eg>[gAIlp  
NqvL,~1G  
!OekN,6  
public class FileAccessI implements Serializable{ o0&jel1a  
o!^':mll  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c 6@!?8J  
RandomAccessFile oSavedFile; Teu4;  
long nPos; 6tB-  
<Rob.x3  
>3s9vdUp4h  
public FileAccessI() throws IOException x0@J~ _0  
{ A;m)/@  
this("",0); ! L:!X88  
} A>(m}P  
==`K$rM  
YFOSv]w  
public FileAccessI(String sName,long nPos) throws IOException FYR%>Em  
{ ?~uTbNR  
oSavedFile = new RandomAccessFile(sName,"rw"); RzQ1Wq  
this.nPos = nPos; GiJ|5"  
oSavedFile.seek(nPos); ,n TC7V  
} Y*;Z(W.V#  
&F9BaJ  
{\j h? P|  
public synchronized int write(byte[] b,int nStart,int nLen) JDfkm+}uY  
{ 'A .c*<_  
int n = -1; :,%~rR  
try{ 1O*5>dkX;%  
oSavedFile.write(b,nStart,nLen); /cF 6{0XS9  
n = nLen; p#hs8xz  
} hH[UIe  
catch(IOException e) xCF k1%qf  
{ E ;65kZ  
e.printStackTrace (); \k/ N/&;  
} _O2},9L n  
c<L^ 1,G2  
F&.iY0Pt  
return n; I!&|L0Qq  
} z(d@!Cd  
=`[08  
)(~4fA5j)  
} IlG)=?8XZ  
V$%%nG uE  
w'z ?1M(*  
/* (g xCP3  
**SiteInfoBean.java iM+K&\{_h  
*/ Kj,C 9  
package NetFox; vJVL%,7  
_"_ W KlN  
a_XM2dc%  
public class SiteInfoBean { /uS(Z-@  
z=:<]j#=  
T{3C3EE?]  
private String sSiteURL; //Site's URL l_GvdD  
private String sFilePath; //Saved File's Path h\".TySz  
private String sFileName; //Saved File's Name S453oG"  
private int nSplitter; //Count of Splited Downloading File /=I&-g xC  
h~haA8i?{  
{Ak{ ct\t  
public SiteInfoBean() x=Z\c,@O  
{//nSplitter的缺省值为5 HMGby2^+  
//default value of nSplitter is 5 Qg;A (\z  
this("","","",5); |#8u:rguy  
} \9;u.&$mNB  
sG`||Kb;n  
0yr=$F(]s  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O9*cV3}H  
{ B2t.;uz(,  
sSiteURL= sURL; XlIRedZ{  
sFilePath = sPath; HSGM&!5mW  
sFileName = sName; *5Upb,* *  
this.nSplitter = nSpiltter; zJJ KLr;  
=<w6yeko  
6, \i0y5n  
} \~!9T5/*  
e@'rY#:u  
0Ci\(  
public String getSSiteURL() k_%2Ok   
{ cnr&%-  
return sSiteURL; {Ts@#V=:  
} Rr ! PU  
3|zqEGT*  
f"t\-ux.b  
public void setSSiteURL(String value) Li~(kw3  
{ fD+'{ivN4  
sSiteURL = value; ?h UC#{  
} u4TU"r("A  
9Axk-c  
T P'  
public String getSFilePath() wHm{4  
{ ,ButNB v  
return sFilePath; =g4^tIYq  
} *0]E4]ZO  
pOP`n3m0  
o`S|  
public void setSFilePath(String value) Sx)b~*  
{ T|^rFaA  
sFilePath = value; %7=B?c |  
} x*td nor&  
ETvn$ Jdp  
m[ *)sm  
public String getSFileName() @ hH;d\W#  
{ i? 5jl&30  
return sFileName; MMg"G6?  
} MGpP'G:v  
9bvzt8pc  
5W"&$6vj  
public void setSFileName(String value) {<0=y#@u  
{ I>ks H  
sFileName = value; 3wZA,Z  
} M{I8b<hY  
am,UUJ+h>  
ol]"r5#Q_H  
public int getNSplitter() J J@O5  
{ gwE#,OY*  
return nSplitter; -oc@$*t  
} tDj~+lmdN  
!K a!f1  
,b;eU[!]  
public void setNSplitter(int nCount) :SFcnYv0  
{ $s$j</.q  
nSplitter = nCount; )>,; GVu"  
} oc .H}Eb%Z  
} mFCDwh]  
eytd@-7uX  
UHr0J jQK  
/* ,iKEIxA!  
**Utility.java *m2{6N_  
*/ [/_M!&zz2  
package NetFox; rPaUDR4U  
^8dd  
SF$'$6x}  
public class Utility { I| j Gu9G  
l)y$c}U  
,>(/}=Z.  
public Utility() Y rq-(  
{ .b'o}DLa  
tXj28sh$  
W vh3Y,|3  
} bvHF;Qywg  
5 :O7cBr  
//线程睡眠 ^Mw>'*5^  
public static void sleep(int nSecond) s;oDwT1  
{ -h=K]Y{`  
try{ 2c?-_OCy;  
Thread.sleep(nSecond); @C[]o.r  
} j2GO ZKy  
catch(Exception e) 8r"$o1!  
{ ZJUTtiD  
e.printStackTrace (); Pl|e?Np  
} 7R9S%  
} qRXQL"Pe_l  
E]G#"EV!Y  
//日志 &Xr@nt0H  
public static void log(String sMsg) >uMj}<g#Z?  
{ K_\fO|<k  
System.err.println(sMsg); 3SbtN3  
} z [xi  
=HJ)!(  
e[txJ*SuO  
public static void log(int sMsg) qmzg68  
{ q5X \wz2N  
System.err.println(sMsg); Rw4"co6  
} qJq49}2  
} K-D{Z7J^l  
hh\\api  
s>}ScJZK  
/* ` VL`8  
**TestMethod.java ;CbQ}k  
*/ h-0sDt pR  
package NetFox; \@yx;}bdI  
Az +}[t  
3#)I7FG  
public class TestMethod { ]"'$i4I{R  
~jK'n4  
d*7nz=0&$  
public TestMethod() WfbG }%&J  
{ ///xx/weblogic60b2_win.exe r>fx5 5dw  
try{ o K;.|ja  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1r6>.&p  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cID{X&or  
SiteFileFetch fileFetch = new SiteFileFetch(bean); #:rywz+  
fileFetch.start(); YGp8./ma<I  
} q,k/@@Qd9  
catch(Exception e){e.printStackTrace ();} FBit /0  
21Z}Zj  
fmH"&>Loc  
} <uGc=Du  
fIOI  
I[|5 DQ  
public static void main(String[] args) 9IFK4>&O6  
{ xE/r:D#  
new TestMethod(); [t^Z2a{  
} jYAD9v%  
} 63b?-.!b  
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