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http断点续传简单实现(java)

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/* {jggiMwo.v  
**SiteFileFetch.java c1jgBty  
*/ vseuk@>  
package NetFox; #sAEIk/  
import java.io.*; %|l*=v  
import java.net.*; &ATjDbW*(  
}g>&l.2X  
]>*Z 1g;  
public class SiteFileFetch extends Thread { _g$6vx&  
{9_CH<$W%U  
4`!(M]u=  
SiteInfoBean siteInfoBean = null; //文件信息Bean +4B>gS[ F  
long[] nStartPos; //开始位置 AR/`]"'  
long[] nEndPos; //结束位置 g0_8:Gs}^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 jNrGsIY$  
long nFileLength; //文件长度 j/dNRleab  
boolean bFirst = true; //是否第一次取文件 cp[4$lu  
boolean bStop = false; //停止标志 H }</a%y  
File tmpFile; //文件下载的临时信息 iMJjWkk  
DataOutputStream output; //输出到文件的输出流 d&.)Dw  
Y 1LE.{  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ML Id3#Q  
public SiteFileFetch(SiteInfoBean bean) throws IOException 0u)]1  
{  5Lm ?  
siteInfoBean = bean; >|uZIcs 6  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); pkBmAJb@  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); a?\ Au  
if(tmpFile.exists ()) V4ayewVX  
{ Gi Zy C  
bFirst = false; O8 k$Uc  
read_nPos(); 1_XdL?h#o  
} $I>.w4G}  
else Sf lHSMFw  
{ b_cD >A  
nStartPos = new long[bean.getNSplitter()]; <:>a51HBX  
nEndPos = new long[bean.getNSplitter()]; Jr 9\j3J{  
} 6S<J'9sE  
+<8r?d2  
gbQrSJs!Zh  
ix*n<lCoC  
} dM#\h*:=  
CXvL`d"  
~ hYG%  
public void run() 60^dzi!vs  
{ F7cv`i?2."  
//获得文件长度 / u>")f  
//分割文件 ewY+a , t  
//实例FileSplitterFetch U6n%rdXJ=  
//启动FileSplitterFetch线程 vSPkm)O0)  
//等待子线程返回 %k5^n0|*  
try{ @<AyCaU`.  
if(bFirst) K`PF|=z  
{ nwHi3ojD:  
nFileLength = getFileSize(); 8]'qJ;E2  
if(nFileLength == -1) 3%!d&j>v  
{ k+&LOb7  
System.err.println("File Length is not known!"); !);'Bk9o  
} Ba6''?;G  
else if(nFileLength == -2) 97'*Xq  
{ V= !!;KR0  
System.err.println("File is not access!"); | u7vY/  
} 4~DFtWbf  
else hSo\  
{ I>b!4?h  
for(int i=0;i<nStartPos.length;i++) ON] z-  
{ |4ONGU*`E  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); X0Xs"--}  
} %0$$tS +  
for(int i=0;i<nEndPos.length-1;i++) q<D'"7#.  
{ ![{>f6{J  
nEndPos = nStartPos[i+1];  ()=  
} N3 07lGb  
nEndPos[nEndPos.length-1] = nFileLength; :74)nbS  
} ;~#rd L  
} qZG "{8  
vfcj,1  
!1w=_  
//启动子线程 *<"xF'C  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xr6UN{_-  
for(int i=0;i<nStartPos.length;i++) _{C:aIl[2  
{ yzgDdAM  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O-}{%)[ F  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YeptYW@xfw  
nStartPos,nEndPos,i); E@Q+[~H}  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j#Bea ,  
fileSplitterFetch.start(); +8v^J8q0  
} 11Pm lzy  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]'EtLFv)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4{[Df$'e>  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qOqQt=ObU  
nEndPos = " + nFileLength); w=e~ M  
// fileSplitterFetch[nPos.length-1].start(); WENPS*0oS]  
 -*M/,O  
A +e ={-*  
//等待子线程结束 8{(;s$H~  
//int count = 0; p\WW~qD  
//是否结束while循环 yL7a*C&  
boolean breakWhile = false; gj0gs  
R<a7TkL4?  
RxjC sjg  
while(!bStop) v<HhB.t.  
{ K8ecSs}}J  
write_nPos(); b'3w.%^  
Utility.sleep(500);  (/-2bO  
breakWhile = true; B9&"/tT  
~?H _?}e  
~(~fuDT~O  
for(int i=0;i<nStartPos.length;i++) {I&>`?7.  
{ -;Y*;xe  
if(!fileSplitterFetch.bDownOver) b(wW;C'#0p  
{ 9EIHcUXe  
breakWhile = false; D[-V1K&g  
break; 7D@O:yO  
} >Ke4lO"  
} F)z]QJOw  
if(breakWhile) N~=p+Ow[H  
break; ts<5%{M(  
CC;T[b&  
c0sU1:e0  
//count++; t$m268m~  
//if(count>4) y9cW&rDH  
// siteStop(); kid3@  
}  Cdin"  
N2 wBH+3w  
"M3R}<Vt  
System.err.println("文件下载结束!"); }*4XwUM e  
} D'$ki[{,  
catch(Exception e){e.printStackTrace ();} MN}@EQvW==  
} &}_E~jKK  
}S\\"SBC  
}Dc0 Y  
//获得文件长度 b%IRIi&,  
public long getFileSize() m-xSF]q=<  
{ p-POg%|&<  
int nFileLength = -1; LBh|4S$K  
try{ @T0F }(k  
URL url = new URL(siteInfoBean.getSSiteURL()); "t$c'`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F4xYfbwY"]  
httpConnection.setRequestProperty("User-Agent","NetFox"); UA>UW!I  
Mj&q"G  
D(yU:^L  
int responseCode=httpConnection.getResponseCode(); PHU#$LG  
if(responseCode>=400) O8%+5l`T!  
{ =;#+8w=^  
processErrorCode(responseCode); 3xj ?}o  
return -2; //-2 represent access is error I kv@}^p 7  
} Uo>pV 9xRG  
80TSE*  
52 ? TLID  
String sHeader; 9lbe[w @  
/GCI`hx>"  
ebxpKtEC  
for(int i=1;;i++) (RW02%`jjy  
{ iG()"^G  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &ejJf{id  
//Utility.log(in.readLine()); !ba /] A/  
sHeader=httpConnection.getHeaderFieldKey(i); Cbv$O o*  
if(sHeader!=null) #EQwl6  
{ u/-u l  
if(sHeader.equals("Content-Length")) d:cs8f4>  
{ 2+y<&[A8U  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ];P$w.0  
break; 1$2'N~`#U  
} 9#Gz2u$  
} biLx-F c  
else }SpjB  
break; -LI^(_  
} 4iMo&E<  
} \Ld/'Z;w  
catch(IOException e){e.printStackTrace ();} CV&+^_j'k  
catch(Exception e){e.printStackTrace ();} s ~c_9,JK  
FRqJ#yd]  
\0?^%CD+@  
Utility.log(nFileLength); |)`<D  
{>$i)B  
o?%1^6&HE  
return nFileLength; X%w`:c&  
} lM oi5q  
`/$yCXy  
:$4 atm  
//保存下载信息(文件指针位置) +0) s {?  
private void write_nPos() \ t4:(Jp 3  
{ O75^(keW  
try{ @AET.qGC  
output = new DataOutputStream(new FileOutputStream(tmpFile)); X!#rw= Q  
output.writeInt(nStartPos.length); ,kS3Ioj  
for(int i=0;i<nStartPos.length;i++) M+4>l\   
{ [*^` rQ  
// output.writeLong(nPos); "O@L IR7  
output.writeLong(fileSplitterFetch.nStartPos); o,}`4_N||  
output.writeLong(fileSplitterFetch.nEndPos); rV;X1x}l  
} r1dP9MT\8  
output.close(); ]U?)_P@}  
} ,tqMMBwC~_  
catch(IOException e){e.printStackTrace ();} 3Run.Gv\  
catch(Exception e){e.printStackTrace ();} BSU%.tmI  
} 8ExEhBX8  
3<">1] /,  
@ )nxX))a  
//读取保存的下载信息(文件指针位置) =*<Cw?Gc  
private void read_nPos() m?wPZ^u  
{  @Tk5<B3  
try{ <=D !/7$ O  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ixc~DV+@[  
int nCount = input.readInt(); G- nS0Kn:  
nStartPos = new long[nCount]; %A_h!3f&  
nEndPos = new long[nCount]; bn$a7\X-  
for(int i=0;i<nStartPos.length;i++) ffDh 0mDN  
{ E$!0h_.(  
nStartPos = input.readLong(); G?Fqm@J{XT  
nEndPos = input.readLong(); $hv o^$  
} qI (<5Wxl  
input.close(); :K J#_y\rt  
} )> >Tj7  
catch(IOException e){e.printStackTrace ();} =@BVO @z@  
catch(Exception e){e.printStackTrace ();} W>[0u3  
} ;J<K/YdI  
[H"\<"1o  
mIk8hA@B_  
private void processErrorCode(int nErrorCode) k/'>,WE  
{ l} \q }7\)  
System.err.println("Error Code : " + nErrorCode); &USKudXmb  
} IXQxjqd^  
i|M^QKvF  
=Rv!c+?  
//停止文件下载 Q)vf>LwC2S  
public void siteStop() )o4B^kq  
{ vSyR% j  
bStop = true; O>FE-0rW}e  
for(int i=0;i<nStartPos.length;i++) &?[uY5Mk  
fileSplitterFetch.splitterStop(); "}/$xOl"  
:<Z>?x  
VAGQR&T?  
} Lmp_8q-Ej  
} C|or2  
//负责部分文件的抓取 #>[BSgW  
**FileSplitterFetch.java .r=F'i}-j*  
*/ _o,Mji|  
package NetFox; 0Z{;sW  
60RYw9d%0  
Ep }{m<8c  
import java.io.*; ^)wTCkH&y  
import java.net.*; [yFf(>B  
8Qm%T7]UFb  
e#{,M8  
public class FileSplitterFetch extends Thread { ?7?hDw_Nk  
3y9R1/!  
I;u1mywd  
String sURL; //File URL 2^3N[pM;  
long nStartPos; //File Snippet Start Position xJ=@xfr$  
long nEndPos; //File Snippet End Position XXwe/>J  
int nThreadID; //Thread's ID mT:Z!sS  
boolean bDownOver = false; //Downing is over "~:AsZ"7  
boolean bStop = false; //Stop identical <4{Jm8zJ  
FileAccessI fileAccessI = null; //File Access interface uC2-T5n'  
O%hmGW4  
Qf=+%-$Y  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException on0MhW  
{ ^*-6PV#Z  
this.sURL = sURL; 6!& DH#M  
this.nStartPos = nStart; r:xbs0 7  
this.nEndPos = nEnd; cJ ^:b4j  
nThreadID = id; PP1?UT=]  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 * |dz.Tr  
} >^odV ;^  
=uG}pgh0  
0 UbY0sYo  
public void run() p]lZ4#3  
{ !=/wpsH  
while(nStartPos < nEndPos && !bStop) ;kE|Vx  
{ Y<vHL<G  
cM|!jnKm  
Tl/!Dn  
try{ 8k.<xWDU  
URL url = new URL(sURL); I=;.o>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8gI f  
httpConnection.setRequestProperty("User-Agent","NetFox"); f$2DV:wuC  
String sProperty = "bytes="+nStartPos+"-"; r9\7I7z  
httpConnection.setRequestProperty("RANGE",sProperty); A ,$CYLj+  
Utility.log(sProperty); 16cc9%   
Qo%IZw$l  
XCAy _fL<B  
InputStream input = httpConnection.getInputStream(); Mtw7aK  
//logResponseHead(httpConnection); k1h>8z.Tg  
:U{$G( <  
GJeP~   
byte[] b = new byte[1024]; p#QR^|7"  
int nRead; #'qDNY@w}  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7]J7'!Iz  
{ `<oNEr+#  
nStartPos += fileAccessI.write(b,0,nRead); CW+]Jv]"  
//if(nThreadID == 1) (H[ .\O-`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K5"8zF)*  
} p)k5Uh"  
v9_7OMl/x  
o1k X`Eu  
Utility.log("Thread " + nThreadID + " is over!"); hKjG/g:#G  
bDownOver = true; q4xP<b^  
//nPos = fileAccessI.write (b,0,nRead); l.iT+T  
} Md5|j0#p  
catch(Exception e){e.printStackTrace ();} Quts~Q  
} pRez${f.(s  
} .@`5>_  
<Na .6P  
Tu[I84  
//打印回应的头信息 C" 2K U*  
public void logResponseHead(HttpURLConnection con) g^mnYg5  
{ <0h,{28  
for(int i=1;;i++) {^ jRV@  
{ FpYeuH%  
String header=con.getHeaderFieldKey(i); JjC& io  
if(header!=null) J=`2{ 'l  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Rk$  
Utility.log(header+" : "+con.getHeaderField(header)); CTP!{<ii  
else tbm/gOBw  
break; YLU.]UC  
} *~%QXNn`  
} :|z.F+-/  
=cwdl7N&I  
~:xR0dqx  
public void splitterStop() `=.A]) >  
{ k>V~ iA  
bStop = true; 86f8b{_e"  
} pH/_C0e`7  
VEG p!~D  
W2T-TI,>PC  
} $ vt6~nfI  
Sa 8T'%W  
K2@],E?e%|  
/* C(J+tbk  
**FileAccess.java Evy_I+l  
*//文件访问(定位,写) 'u84d=*l  
package NetFox; 2,^ U8/  
import java.io.*; >V$ S\"  
}9*NEU) o  
(/^dyG|X'  
public class FileAccessI implements Serializable{ 3;<Vv*a"Dm  
I*`;1+`  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %c-T Gr,  
RandomAccessFile oSavedFile; `#c36  
long nPos; t^|GcU]  
.:(T}\]R  
r=4vN=:  
public FileAccessI() throws IOException *!c&[- g  
{ ,w|Or}h]7  
this("",0); x4Wu`-4^  
} @;b @O _  
9lR-  
A2p]BW&  
public FileAccessI(String sName,long nPos) throws IOException ?C`&*+  
{ E06)&tF  
oSavedFile = new RandomAccessFile(sName,"rw"); -A(]U"@n  
this.nPos = nPos; ('oA{,#L  
oSavedFile.seek(nPos); 4DV@-  
} GWCU 9n  
?d5_{*]+v  
 8\Uy  
public synchronized int write(byte[] b,int nStart,int nLen) gaC [%M  
{ .qfU^AHA  
int n = -1; Zk<Y+!  
try{ 8k9q@FSln  
oSavedFile.write(b,nStart,nLen); k* e $_  
n = nLen; ]uZaj?%J<  
} Dk#4^`qp1  
catch(IOException e) pdq5EUdS  
{ SpA-E/el  
e.printStackTrace (); *OU&`\bmE  
} fI"OzIJV  
VxqoE]Dh  
+&*Ybbhb  
return n; D^<5gRK?  
} I/k/5  
|h%0)_  
myqQqVW  
} v:zKn[;o  
mBON>Z [4.  
^"GDaMF  
/* ~@%#eg  
**SiteInfoBean.java 6 vr8rJ-  
*/ nPg,(8Tt  
package NetFox; YtFH@M  
()ZP =\L  
K0^Tg+U($p  
public class SiteInfoBean { ?!;i/h*{  
/?B%,$~  
[t+qYe8  
private String sSiteURL; //Site's URL P,*yuF|bk  
private String sFilePath; //Saved File's Path 4#&w-W  
private String sFileName; //Saved File's Name N D1'XCN  
private int nSplitter; //Count of Splited Downloading File z:W|GDD1  
5]F4.sa  
HzZ.q2Zz%  
public SiteInfoBean() kB]?95>Wx  
{//nSplitter的缺省值为5 `^'0__<M  
//default value of nSplitter is 5 3!Cab/T  
this("","","",5); ot; ]?M  
} SS7C|*-Zd  
$m[* )0/  
UYkuz  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U`kO<ztk  
{ gI{56Z  
sSiteURL= sURL; Ur,{ZGm  
sFilePath = sPath; "VI2--%v3  
sFileName = sName; p.RSH$]  
this.nSplitter = nSpiltter; aSH =|Jnc  
@tVl8]y  
+x)x&;B)/  
} h{.x:pPXy  
Hq0O!Zv  
<ql:n  
public String getSSiteURL() UdK+,k~m/  
{ U!i@XA%P  
return sSiteURL; $&KiN82,  
} M <c cfU!  
o!sHK9hvJ)  
F ,h}HlU  
public void setSSiteURL(String value) 2U rE>_  
{ XT{o ]S~nq  
sSiteURL = value; 41 #YtZ  
} ?a{>QyL  
=g<Yi2  
%+ur41HM  
public String getSFilePath() f@H>by N  
{ ^)S<Ha  
return sFilePath; @i=_y+|d_  
} uE^5o\To  
oRQ( l I>  
m:5x"o7)ln  
public void setSFilePath(String value) vg-'MG  
{ _GsHT\  
sFilePath = value; tW=oAy  
} t&nK5p95(  
b0h>q$b  
F:'>zB]-}  
public String getSFileName() R:Tv'I1-L  
{ R0bWI`$Z  
return sFileName; ^9`~-w  
} -MuKeCgi  
~5 e 1&  
q|S,^0cU  
public void setSFileName(String value) f1X]zk(=W  
{ 2PQY+[jx  
sFileName = value; =e|  
} %40+si3c  
(&xIB F_6  
tN-B`d 1  
public int getNSplitter() 0s%]%2O N  
{ &U{"dJr  
return nSplitter; 'aJm4W&j  
} wY_! s Qo  
}080=E  
*(j -jbA  
public void setNSplitter(int nCount) uV\~2#o$_  
{ f\c%G=y  
nSplitter = nCount; b_GAK  
} '[Z.\   
} Rq,Fp/  
dZ"d`M>o6  
DP=\FG"}x  
/* $*vj7V_  
**Utility.java * vP:+]  
*/ 0&2eiMKG?n  
package NetFox; Q)ZbnR2Z8  
w02t9vz  
_0!<iN L  
public class Utility { [J+]1hCZ|  
"Tc[1{eI  
#b+>O+vx8  
public Utility() &d i=alvv1  
{ g0 Jy:`M  
z:p9&mi  
U?(+ {4l  
} ^|lG9z%Foy  
B+2Jea,N  
//线程睡眠 .MI 5?]_  
public static void sleep(int nSecond) D}L4uz?  
{ nCPIpw,]M  
try{ 0;:AT|U/d  
Thread.sleep(nSecond); pb}4{]sI  
} &1M#;rE;D#  
catch(Exception e) }W$}blbp  
{ xT;j_'9U;  
e.printStackTrace (); .R{+Pz D  
} Aj "SSX!L  
} .q_SA-!w>  
HFTDea+#  
//日志 axLO: Q,  
public static void log(String sMsg) C5&+1VrP  
{ _Rey~]iJJ8  
System.err.println(sMsg); +8|r_z\A5a  
} Wm>AR? b  
*[0)]|r  
hnnPi  
public static void log(int sMsg) Y"'k $jS-  
{ VDC"tSQ  
System.err.println(sMsg); {6 brVN.V  
} 5HMDug;   
} jW0aIS2O  
YV"LM6`  
z+F:_  
/* O:Ob{k  
**TestMethod.java w"?E=RS  
*/ l527>7 eT  
package NetFox; iYl$25k/1  
f f_| 3G  
+d/^0^(D\5  
public class TestMethod { kJ:zMVN  
l$eKV(CZ4  
77o&$l,A|  
public TestMethod() ?8aPd"x  
{ ///xx/weblogic60b2_win.exe jG~UyzWH;  
try{ V'XvwO@  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J&jig?t  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aFVd}RO0  
SiteFileFetch fileFetch = new SiteFileFetch(bean); >? ({  
fileFetch.start(); W.VyH|?  
} 2Ik@L,  
catch(Exception e){e.printStackTrace ();} X^ZUm  
ffE&=eh)  
uq_h8JH$  
} |4u?Q+k%%  
8@'Q=".J  
*'h vYl/?>  
public static void main(String[] args) @iD5X.c  
{ Rhil]|a/  
new TestMethod(); NJTC+`Hm  
} N~@VZbS(6  
} fE&wtw{gi  
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