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http断点续传简单实现(java)

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/* h}*/Ge]aM  
**SiteFileFetch.java J#w J4!  
*/ +1uF !G&l  
package NetFox; WlB  
import java.io.*; 4A8;tU$&  
import java.net.*; @Fluc,Il  
O #F   
gYNjzew'  
public class SiteFileFetch extends Thread { GNgKo]u  
.LZwuJ^;  
q@Zn|NR  
SiteInfoBean siteInfoBean = null; //文件信息Bean 8VeQ-#7M/  
long[] nStartPos; //开始位置 T V<'8 L  
long[] nEndPos; //结束位置 brW :C? }  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 RZHd9v$  
long nFileLength; //文件长度 [NaN>BZ?  
boolean bFirst = true; //是否第一次取文件 7Nk!1s :  
boolean bStop = false; //停止标志 >64P6P;S  
File tmpFile; //文件下载的临时信息 ]QpWih00V  
DataOutputStream output; //输出到文件的输出流 8"U. Hnu  
wCr(D>iM  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) v{(^1cX  
public SiteFileFetch(SiteInfoBean bean) throws IOException S#MZV@nGF  
{ X#*JWQO=  
siteInfoBean = bean; N):tOD@B  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ;g@4|Ro  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 2>cGH7EBD  
if(tmpFile.exists ()) =-8bsV/l  
{ z`!XhU  
bFirst = false; uW30ep'  
read_nPos(); $ {O#  
} F$ #U5}Q  
else jBgP$g  
{ jF0jkj1&/[  
nStartPos = new long[bean.getNSplitter()]; xD5:RE~g  
nEndPos = new long[bean.getNSplitter()]; *pSQU=dmS  
} V8rx#H~  
n@C[@?D  
y0#u9t"Z;  
U^Q:Y}^  
} $}) g?Q  
(Dw,DY9  
^lA=* jY(  
public void run() 8zRP (+&W  
{ KVT-P};jy*  
//获得文件长度 DVSL [p?_  
//分割文件 P(H8[,  
//实例FileSplitterFetch ^G4 P y<s  
//启动FileSplitterFetch线程 mS~o?q-n  
//等待子线程返回 hp#W 9@NR  
try{ SZ,YS 4M  
if(bFirst) ~$)2s7 O  
{ )L#i%)+  
nFileLength = getFileSize(); +89*)pk   
if(nFileLength == -1) h|,:e;>}  
{ 8,C*4y~  
System.err.println("File Length is not known!"); n?- })  
} x4E7X_  
else if(nFileLength == -2) a0D%k:k5  
{ "uaMk}[ <!  
System.err.println("File is not access!"); =<?+#-;p  
} ;1%-8f:lW  
else -_1>C\h"  
{ qU#1i:(F*  
for(int i=0;i<nStartPos.length;i++) _F$aUtb%O  
{ V:VO[e<e  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Cj{1H([-  
} -'t)=YJ  
for(int i=0;i<nEndPos.length-1;i++) 0:9.;x9_  
{ xa<UM5eI  
nEndPos = nStartPos[i+1]; vUohtS*  
} XCU7x i$d  
nEndPos[nEndPos.length-1] = nFileLength; L)@?e?9  
} G#d{,3Gq1  
} !,6c ~ w  
C~o7X^[R\  
X]wRwG  
//启动子线程 vb<oi&X  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |}(`kW  
for(int i=0;i<nStartPos.length;i++) 7?GIS '  
{ m^ tFi7c  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^/\Of{OZ-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vgfcCcZ_iZ  
nStartPos,nEndPos,i); (9Ux{@$o[  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }]lr>"~y}  
fileSplitterFetch.start(); @ycDCB(D}  
} B?'#4J  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \=:~ki=@B  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y]/% t{Y  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +n{#V;J  
nEndPos = " + nFileLength); mLP.t%?#   
// fileSplitterFetch[nPos.length-1].start(); -f%'  
-* WXMzr  
+l9!Fl{MK\  
//等待子线程结束 n1ly y0%u  
//int count = 0; BG6B :  
//是否结束while循环 4^WpS/#4  
boolean breakWhile = false; <<+\X:,  
^c^#dpn  
4dO~C  
while(!bStop) IC1NKn<k  
{ $$ Oey)*  
write_nPos(); WvBc#s-  
Utility.sleep(500); p i %< Sy  
breakWhile = true; A OISs4  
fI{&#~f4C  
x:),P-~w  
for(int i=0;i<nStartPos.length;i++) 5nT"rA  
{ jL%x7?*U0  
if(!fileSplitterFetch.bDownOver) W6?pswQ  
{ ="Ho%*@6  
breakWhile = false; eg(6^:z?f  
break; OB Otuu.  
} @k,z:~[C=  
} =t9\^RIx)?  
if(breakWhile) j27?w<  
break; VH9dleZ  
%?}33yV  
LhOa{1SY  
//count++; bCo7*<I4  
//if(count>4) 6$kqaS##  
// siteStop(); cq}EZ@ .  
} '*5i)^  
=Je[c,&j$?  
QEz? w}b*  
System.err.println("文件下载结束!"); B* ?]H*K  
} JmxH"7hTE  
catch(Exception e){e.printStackTrace ();} B:'J `M"N  
} Z/k:~%|E  
OGK}EI  
~Sj9GxTe  
//获得文件长度 i,>khc  
public long getFileSize() '[AlhBX  
{ 63\/ * NNB  
int nFileLength = -1; XGYbnZ~   
try{ K2TcOFQ  
URL url = new URL(siteInfoBean.getSSiteURL()); "I3@m%qv  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OLyf8&AU@  
httpConnection.setRequestProperty("User-Agent","NetFox"); #.rdQ,)<  
8aK)#tNWN  
^q{9  
int responseCode=httpConnection.getResponseCode(); |iakz|])  
if(responseCode>=400) l4F%VR4KT  
{ z* ^_)Z  
processErrorCode(responseCode); SIBtmm1W  
return -2; //-2 represent access is error =bfJ^]R  
} wjH zE  
8EW_V$>R  
aOlT;h  
String sHeader; dq(uVW^&ae  
.YhA@8nc~l  
"|EM;o  
for(int i=1;;i++) LInz<bc<(  
{ T1ut"Zu  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4w*Skl=F}  
//Utility.log(in.readLine()); 7?#J~.d5  
sHeader=httpConnection.getHeaderFieldKey(i); >"^ O"E  
if(sHeader!=null) ]O]4z,n  
{ 2^r <{0@n  
if(sHeader.equals("Content-Length")) }JF13beU  
{ %'b M){  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /KFfU1  
break; zwhe  
} y&6FybIz  
} N4v~;;@(  
else fY{1F   
break; H=<S 9M  
} 3k\#CiB{  
} Z_$%.  
catch(IOException e){e.printStackTrace ();} Lf16j*}-Q  
catch(Exception e){e.printStackTrace ();} (7vF/7BZ|_  
t>L;kRujVJ  
vmU@^2JSJ  
Utility.log(nFileLength); J=\HO8E6>  
#*D)Q/k  
M\o9I  
return nFileLength; >=qf/K +#  
} )B T   
r /YMLQ  
\.0^n3y  
//保存下载信息(文件指针位置) YJ^] u}  
private void write_nPos() 7r7YNn/?  
{ TITKj?*o  
try{ ;ic3).H  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?Y$JWEPJ  
output.writeInt(nStartPos.length); iJ-23_D  
for(int i=0;i<nStartPos.length;i++) \MA+f~)9  
{ IshKH -  
// output.writeLong(nPos); .7Dtm<K#  
output.writeLong(fileSplitterFetch.nStartPos); i5en*)O8  
output.writeLong(fileSplitterFetch.nEndPos); Z~AO0zUKY  
} V_R@o3kv;  
output.close(); ./- 5R|fN  
} iIvc43YV%  
catch(IOException e){e.printStackTrace ();} *M[?bk~~  
catch(Exception e){e.printStackTrace ();} O [\i E5+$  
} r(6Y*<  
1 8|m)(W  
QCD .YFM  
//读取保存的下载信息(文件指针位置) sr r :!5  
private void read_nPos() q]\:P.x!>  
{ GD&uQ`Y5  
try{ ls_'')yp  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); aEFJ;n7m  
int nCount = input.readInt(); JUsQ,ETn  
nStartPos = new long[nCount]; 9/{(%XwX  
nEndPos = new long[nCount]; Y#]+Tm (+  
for(int i=0;i<nStartPos.length;i++) . S!mf  
{ [^R^8k  
nStartPos = input.readLong(); #9B)Xx!g  
nEndPos = input.readLong(); (jnzT=y  
} y_'Ub{w  
input.close();  Hu^1[#  
} hjU::m,WX  
catch(IOException e){e.printStackTrace ();} 0QB iC]9  
catch(Exception e){e.printStackTrace ();} H~oail{EQ  
} 0m7Y>0wC6T  
x5|I  
5<iV2Hx  
private void processErrorCode(int nErrorCode) ,QOG!T4  
{ OtY`@\hy  
System.err.println("Error Code : " + nErrorCode); <m!h&_eg  
} \n"{qfn`r  
 jPC[_g  
~9?cn  
//停止文件下载 _ ?TN;  
public void siteStop() d4m=0G`  
{ ?RX3MUN  
bStop = true; *w$W2I>b7  
for(int i=0;i<nStartPos.length;i++) $[9%QQk5<L  
fileSplitterFetch.splitterStop(); ~ {?_p@&n  
E_gD:PPU5  
S_iMVHe  
} +cWLjPD/}  
} A]y`7jJ  
//负责部分文件的抓取 7.-V-?i  
**FileSplitterFetch.java x9NEFtqjm  
*/ ?42<J%p  
package NetFox; u=Fv 2  
>@BnV{ d  
> pgX^  
import java.io.*; he#J|p  
import java.net.*; y9_V  
HPpR.  
3yANv?$a  
public class FileSplitterFetch extends Thread { I\hh8abAp  
gwNq x"  
-_ I _W&  
String sURL; //File URL 3sc+3-TF  
long nStartPos; //File Snippet Start Position MU>k,:[  
long nEndPos; //File Snippet End Position *v?`<)P#  
int nThreadID; //Thread's ID YW-usvl&  
boolean bDownOver = false; //Downing is over H!vax)%-\  
boolean bStop = false; //Stop identical s.EI`*xylY  
FileAccessI fileAccessI = null; //File Access interface 2`.cK 3  
?xK8#  
b>_o xK  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fz;iOjr>  
{ TP VVck-T8  
this.sURL = sURL; M]<?k]_p  
this.nStartPos = nStart; Usg K  
this.nEndPos = nEnd; R5"K]~  
nThreadID = id; $GYm6x\4  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tM2)k+fg  
} tzZ63@cm  
3WN`y8l  
/`9sPR6e  
public void run() aF8fqu\  
{ SH3|sXH<  
while(nStartPos < nEndPos && !bStop) ^<;V]cY`  
{ h1:aKm!  
b`L%t:u{d  
r/& sub"X  
try{ Z.d 7U~_  
URL url = new URL(sURL); Y;nZ=9Sw  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f @8mS    
httpConnection.setRequestProperty("User-Agent","NetFox"); ,PlO8;5]  
String sProperty = "bytes="+nStartPos+"-"; >Wh}f3C  
httpConnection.setRequestProperty("RANGE",sProperty); H&F9J ^rC  
Utility.log(sProperty); %509\;el  
3Uqr,0$p  
'iy*^A `Y  
InputStream input = httpConnection.getInputStream(); ^?$WVB  
//logResponseHead(httpConnection); vK(i 9>;7  
b:=TB0Fx?n  
Fd?"-  
byte[] b = new byte[1024]; y'FS/=u>0  
int nRead; OF%B[h&   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b5,x1`#7k  
{ "8'@3$>R=  
nStartPos += fileAccessI.write(b,0,nRead); jxiC Kx,G  
//if(nThreadID == 1) 3:5 &Aa!  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); : k7uGD  
} p7);uF^O%  
;`l'2 z@N  
"~=mG--I  
Utility.log("Thread " + nThreadID + " is over!"); 1?)Xp|O  
bDownOver = true; $k0k k  
//nPos = fileAccessI.write (b,0,nRead); wx\v:A  
} H(2!1?N+  
catch(Exception e){e.printStackTrace ();} a UxGzMZ  
} D6CS8 ~"  
} MepuIh  
7Q7-vx  
\|]Z8t7  
//打印回应的头信息 ,QC{3i~  
public void logResponseHead(HttpURLConnection con) ;=geHiQHA  
{ +zu(  
for(int i=1;;i++) o[v\|Q`d  
{ ak ->ML  
String header=con.getHeaderFieldKey(i); *\(r+>*x*  
if(header!=null) /c"efnb!  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ET_W-  
Utility.log(header+" : "+con.getHeaderField(header)); ^M%uV  
else z^_*&  
break; so)"4 SEu  
} SF}<{x_  
} _ ):d`O e  
F.-R r  
vohoLeJTj  
public void splitterStop() RletL)  
{ <EPj$::  
bStop = true; rEHkw '  
} AtU v71D:  
lZyG)0t,g  
.Q@S #d  
} W?0 lV5/  
"Vw m  
SrFS#  
/* AjJURn0`,!  
**FileAccess.java >ELlnE8  
*//文件访问(定位,写) hX`hs- *qM  
package NetFox; K`/`|1  
import java.io.*; ?."&MZ  
`W dD8E  
,ldI2 ]  
public class FileAccessI implements Serializable{ V$"ujRp  
>N;F8v  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JYrY[',u  
RandomAccessFile oSavedFile; ZDD..j  
long nPos; rsF\JQk  
5DXR8mLoaJ  
/;7y{(o  
public FileAccessI() throws IOException y" 6y!  
{ e'*`.^  
this("",0); +2K:qvzZ  
} N[<H7_/3  
cTXri8K_  
H;U)b{  
public FileAccessI(String sName,long nPos) throws IOException JCPUM *g8  
{ FuUD 61JHY  
oSavedFile = new RandomAccessFile(sName,"rw"); &K43x&mFF  
this.nPos = nPos; pG34Qw  
oSavedFile.seek(nPos); 21ppSN >  
} -D N8Yb  
 |y h\  
P7 ]z  
public synchronized int write(byte[] b,int nStart,int nLen) 'Q =7/dY3I  
{ 7}GK%H-u  
int n = -1; WYIQE$SEv  
try{ 277ASCWLkU  
oSavedFile.write(b,nStart,nLen); ~%/Wupf  
n = nLen; ?9HhG?_x  
} E]J:~H'Er  
catch(IOException e) &n[~!%(  
{ Z1ALq5  
e.printStackTrace (); iweD @b  
} T1` |~Z?g-  
qC_mu)6  
zOHypazOTq  
return n; Nrah;i+H\o  
} [w0/\]o  
GyW.2  
[3W*9j  
} 0l=+$& D  
tM,%^){p$  
ESg+n(R  
/* O1D6^3w  
**SiteInfoBean.java ~1*A  
*/ dl5=q\1=  
package NetFox; QN>7~=`  
FG%j {_Ez  
sBK <zR  
public class SiteInfoBean { '~ 4pl0TWc  
EQIUSh)M  
oyk>vIZ  
private String sSiteURL; //Site's URL ?( =p<TUw  
private String sFilePath; //Saved File's Path 0@5E|<A  
private String sFileName; //Saved File's Name 16X@^j_   
private int nSplitter; //Count of Splited Downloading File Z~6[ Z  
Fl{WAg  
3ta$L"a  
public SiteInfoBean() :%JC^dV(  
{//nSplitter的缺省值为5 0rokR&Y-d  
//default value of nSplitter is 5 S'U@X  
this("","","",5); CKlL~f EL  
} 2X88:  
'R9g7,53R  
bm}6{28R  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~|Z'l%<Os  
{ J$9:jE-4  
sSiteURL= sURL; 64j|}wJ$  
sFilePath = sPath; k$Rnj`*^  
sFileName = sName; y69J%/c ra  
this.nSplitter = nSpiltter; /^#G0f*N  
u-DK_^v4M  
!EF(*~r!9L  
} (LJ@S eM;  
'GJVWpvUU  
IeF keE  
public String getSSiteURL() ] c}91  
{ uXQ >WI@eF  
return sSiteURL; Di Or{)a  
} kII7z;<^`  
VjbG(nB?_  
~ eN8|SR  
public void setSSiteURL(String value) *(GZ^QH.  
{ cs_}&!c{  
sSiteURL = value; Di=9mHC  
} oP,9#FC|(  
BH@b1}  
xi'<y  
public String getSFilePath() %85Icg  
{ !rTmR@e$/  
return sFilePath; 6J%iZ  
} (U87}}/l  
IS]{}Y\3H  
ua 8m;>R  
public void setSFilePath(String value) }fIqH4bp  
{ }qC SS<a  
sFilePath = value; ARL  
} d*;$AYI#R  
J\W-dI  
*,#q'!Hq  
public String getSFileName() s` >H  
{ o;J;*~g  
return sFileName; @R:#"  
} V 2kWiyN  
s3lJu/Xe{  
oL *n>dH  
public void setSFileName(String value) )&Z>@S^  
{ c<qe[iyt/  
sFileName = value; }. %s xw  
} +cfziQ$'  
_J"mR]I+  
0B3 Q Vbp'  
public int getNSplitter() 9[>Lp9l'  
{ zW'/2W.  
return nSplitter; ;9rTE|n  
} ^eTZn[qH>w  
=g0*MZ;"  
;?im(9h"v!  
public void setNSplitter(int nCount) sX'U|)/pD  
{ :{CFTc5:A  
nSplitter = nCount; MTB@CP!u  
} h=f6~5l5  
} Ff/Ig]Lb  
Ve:&'~F2 s  
T0L+z/N_m.  
/* ggCr-  
**Utility.java 7jezw'\=~  
*/  M]0^ind  
package NetFox; 4 ?2g&B\  
_[$# b]V  
wG:$6  
public class Utility { S_T  
FH -p!4+]  
XWF7#xM  
public Utility() s*{mT6s+T  
{ QJM(UfHUD  
=|# w.(3y  
zPE#[\O21B  
} {3 SdX  
ris;Iu^v0  
//线程睡眠 Uf[T_  
public static void sleep(int nSecond) R8{e&n PE  
{ Z]e4pR6!  
try{ hwZ6 .  
Thread.sleep(nSecond); toN  
}  qV?sg  
catch(Exception e) u mqKFM$  
{ 9g+UJ\u^  
e.printStackTrace (); MyM+C}  
} Ku&*`dME  
} J2Y 3er  
<q1'Li)_R  
//日志 &V FjH W  
public static void log(String sMsg) q'fPNQg  
{ Yg|l?d"  
System.err.println(sMsg); j`+0.Zlq  
} WkcH5[  
T!&jFy*W  
XzN-slu!  
public static void log(int sMsg) [ArO$X3\  
{ bA0uGLc  
System.err.println(sMsg); s|BX> 1  
} qU}lGf!dVn  
} ^$8Vh =D  
Qlf 9]ug)  
HUD7{6}4  
/* Sn+FV+D  
**TestMethod.java olHH9R9:  
*/ rSzQUn<  
package NetFox; EI%M Azj}  
li1v 4  
65;|cmjv  
public class TestMethod { v hR twi  
u~ Vs wXc4  
;K>{_k f  
public TestMethod() (0X,Qwx  
{ ///xx/weblogic60b2_win.exe 8H&_,;  
try{ |K'Gw}fX/  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l@~1CMyN  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :QxL 9&"  
SiteFileFetch fileFetch = new SiteFileFetch(bean); >a?OXqYP  
fileFetch.start(); 9*7Hoi4Ji  
} &NlS  =  
catch(Exception e){e.printStackTrace ();} xI-=t ib  
)PsN_ 42~  
kQqBHA  
} N)9pz?*V  
9k714bnMLX  
Fl8w7LcF7  
public static void main(String[] args) E \ K  
{ =# k<Kw#  
new TestMethod(); i5ajM,i/K  
} ; ,Of\Efc|  
} D2>hMc  
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