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http断点续传简单实现(java)

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/* 0^44${bA  
**SiteFileFetch.java U|odm58s  
*/ m'1NZV%#  
package NetFox; #|^7{TN   
import java.io.*; 5r/QPJ<h  
import java.net.*; 6suB!XF;  
Z5~dU{XsT  
WH :+HNl1d  
public class SiteFileFetch extends Thread { L;.6j*E*  
X70vDoW  
j9C=m"O  
SiteInfoBean siteInfoBean = null; //文件信息Bean 5n;|K]UW  
long[] nStartPos; //开始位置 Avw"[~Xd  
long[] nEndPos; //结束位置 M64zVxsd  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 .FK'T G  
long nFileLength; //文件长度 Ne/jvWWN  
boolean bFirst = true; //是否第一次取文件 /:dVW" A|  
boolean bStop = false; //停止标志 Y.rHl4  
File tmpFile; //文件下载的临时信息 {(G@YG?  
DataOutputStream output; //输出到文件的输出流 %o< &O(Y  
#FF5xe  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) /b@0HL?  
public SiteFileFetch(SiteInfoBean bean) throws IOException >K#Z]k  
{ Vja' :i  
siteInfoBean = bean; FVLXq0<Cj  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ~Av]LW  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); SqY;2:  
if(tmpFile.exists ()) jM J[6qj  
{ "d'xT/l "  
bFirst = false; yZI4%fen  
read_nPos(); G1B~?i2$ ?  
} G~)jk+Qq  
else 'ntb.S)  
{ *sf9(%j  
nStartPos = new long[bean.getNSplitter()]; ] d| -r:4  
nEndPos = new long[bean.getNSplitter()]; :YjOv  
} "Ks%!  
!Dkz6B*  
Q"8)'dL'  
'xZxX3  
} ,: w~-   
)?'sw5C  
,)V*xpp  
public void run() `ZN@L<I6  
{ =Z/'|;Vd_x  
//获得文件长度 ` 2|~Z H  
//分割文件 hX)r%v:  
//实例FileSplitterFetch =pWpHbB.  
//启动FileSplitterFetch线程 fh$U"  
//等待子线程返回 En6fmEn&;o  
try{ 5`oor86  
if(bFirst) W_8 FzXA  
{ 05*_h0}  
nFileLength = getFileSize(); 'DsfKR^ s  
if(nFileLength == -1) &0f7>.y  
{ [k-7Kq  
System.err.println("File Length is not known!"); 8q7KqYu  
} f]$ g9H  
else if(nFileLength == -2) %H<w.]>  
{ _KmpC>J+  
System.err.println("File is not access!"); ~2@U85"o  
} K *vNv 4  
else V2w[0^ L  
{ {z@vSQ=)=P  
for(int i=0;i<nStartPos.length;i++) HAo8]?J  
{ ] >ipC,v  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Djf2ir'  
} toTAWT D  
for(int i=0;i<nEndPos.length-1;i++) /dOQ4VA\  
{ pRc(>P3;  
nEndPos = nStartPos[i+1]; y(.WK8  
} !nVX .m9  
nEndPos[nEndPos.length-1] = nFileLength; 1sc #!^Oo  
} mm#U a/~1u  
} TOMvJ>bF  
g/z9bOgIX  
e/;Ui  
//启动子线程 Kox~k?JK  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b,T=0W  
for(int i=0;i<nStartPos.length;i++) Zpb3>0<R  
{ }J`{g/  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2l5@gDk5  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [%l+ C~m  
nStartPos,nEndPos,i); EUuMSDp  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '4Z%{.;  
fileSplitterFetch.start(); ^0{S!fs  
} m_rRe\  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e7#=F6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qx0o,oZN!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V<4)'UI?k9  
nEndPos = " + nFileLength); (!X:[Ah*$  
// fileSplitterFetch[nPos.length-1].start(); u6r-{[W}  
xDADJ>u2K  
mSQ!<1PM  
//等待子线程结束 W\~ZmA.  
//int count = 0; "r"]NyM  
//是否结束while循环 /Z2*>7HM8[  
boolean breakWhile = false; qWE"vI22M  
nj7Ri=lyS  
Z/-%Eb]L1  
while(!bStop) '2[ _U&e  
{ ^"buF\3L  
write_nPos(); ?U-p jjM  
Utility.sleep(500); '[-H].-!   
breakWhile = true; ^;@Bz~Z  
'3hvR4P  
)1x333.[c  
for(int i=0;i<nStartPos.length;i++) 0l 3RwWj  
{ /-|xxy  
if(!fileSplitterFetch.bDownOver) $ @1&G~x  
{ `SW`d<+L  
breakWhile = false; -IX;r1UD  
break; MeplM$9  
} 8#Z$}?W  
} RuRJjcnY  
if(breakWhile) e:7aVOm  
break; N,[M8n,  
cQ+, F2  
'!1lK  
//count++; p$9N}}/c  
//if(count>4) R*yB);p  
// siteStop(); K4R jGSaF  
} $^ >n@Q@&L  
V;:A&  
9h0|^ttF  
System.err.println("文件下载结束!"); > %Y#(_~a  
} T3?kabbF  
catch(Exception e){e.printStackTrace ();} ;F0A\5I  
} -5>g 0o2  
T@vVff  
>LLzG  
//获得文件长度 *n[Fl  
public long getFileSize() Sr+1.77}  
{ A,=l9hE'  
int nFileLength = -1; wK\SeX  
try{ 3QR-8  
URL url = new URL(siteInfoBean.getSSiteURL()); *v5y]E%aW  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a9qZI  
httpConnection.setRequestProperty("User-Agent","NetFox"); g)p[A 4  
=G72`]#-  
cxv) LOl-  
int responseCode=httpConnection.getResponseCode(); pEaH^(I*  
if(responseCode>=400) }oU&J81  
{ ~~fL`"  
processErrorCode(responseCode); WYzY#-j  
return -2; //-2 represent access is error gTQ6B,`/8  
} Xs?>6i@$$  
zYs? w=  
(f.A5~e  
String sHeader; ?t%5/  
<kM%z{p  
EwOTG Y{0p  
for(int i=1;;i++) .-34 g5  
{ d[Fsp7U}  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'V>+G>U  
//Utility.log(in.readLine()); e| l?NXRX  
sHeader=httpConnection.getHeaderFieldKey(i); 2'}2r ~6  
if(sHeader!=null) =VSieh  
{ {Y/  
if(sHeader.equals("Content-Length")) < 1r.p<s  
{ LaIif_fie^  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ){(cRB$  
break; SMy&K[hJ[  
} LpiLk| 2i  
} d)AkA\neWo  
else a* D|$<V  
break; QMsnfG  
} EPg?jKZava  
} #nxx\,i>  
catch(IOException e){e.printStackTrace ();} u4nXK <KL|  
catch(Exception e){e.printStackTrace ();} Fca?'^X  
wvYxL c#p0  
aOuon0  
Utility.log(nFileLength); W>Kwl*Cis"  
VuR BJ2D  
x$p\ocA  
return nFileLength; 97 g-*K  
} ejQCMG7  
=0-qBodbl  
Z:OO|x  
//保存下载信息(文件指针位置) KWYG\#S0]  
private void write_nPos() 0qZ)$ YKq  
{ g[n8N{s  
try{ FP Mk&  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;K_B,@:'  
output.writeInt(nStartPos.length); g-s@m}[T  
for(int i=0;i<nStartPos.length;i++) V:+bq`  
{ oe<Y,%u"6  
// output.writeLong(nPos); hh{liS% 10  
output.writeLong(fileSplitterFetch.nStartPos); OH(+]%B78  
output.writeLong(fileSplitterFetch.nEndPos); i0!F  
} f_\-y&)+*  
output.close(); kO#`m ]  
} )}aF=%  
catch(IOException e){e.printStackTrace ();} K_xOY *  
catch(Exception e){e.printStackTrace ();} h ^c'L=dR  
} (l,o UBRr  
sDC RL%0QK  
5C&f-* Bh  
//读取保存的下载信息(文件指针位置) |q>Mw-=  
private void read_nPos() utE:HD.PN  
{ 5 6R,+sN  
try{ !< )_ F  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GwycSb1  
int nCount = input.readInt(); M}<=~/k`j  
nStartPos = new long[nCount]; +u2Co_FJ&  
nEndPos = new long[nCount]; D^~g q`/)  
for(int i=0;i<nStartPos.length;i++)  {MtB!x  
{ ^`7t@G$ D  
nStartPos = input.readLong(); t<7WM'2<y  
nEndPos = input.readLong(); yKI.TR#  
} V Y3{1Dlf  
input.close(); Yp)U'8{h c  
} 00p 7sZU^  
catch(IOException e){e.printStackTrace ();} Ed-gYL^<  
catch(Exception e){e.printStackTrace ();} w;(gi  
} {|%O)fr,  
[:'n+D=T3M  
C"{on%  
private void processErrorCode(int nErrorCode) yM2&cMHH~  
{ LA+MX 0*  
System.err.println("Error Code : " + nErrorCode); v3"xJN_,[p  
} lN'/Z&62  
H-W) Tq_?-  
a\w | tf  
//停止文件下载 "=(;l3-o  
public void siteStop() {Jc!T:vJ  
{ aiHr2x6  
bStop = true; d/&|%Z r  
for(int i=0;i<nStartPos.length;i++) \_E.%K  
fileSplitterFetch.splitterStop(); fz3*oJ'  
pYG,5+g  
* 2%e.d3"M  
} Uz|]}t5V  
} Om  
//负责部分文件的抓取 q9!9OcN2  
**FileSplitterFetch.java 4QNR_w  
*/ ->8q, W2A  
package NetFox; d@tr]v5 B  
`[CJtd2\  
E2|iAT+=.  
import java.io.*; obq}#  
import java.net.*; M<unQ1+wh  
+a-@ !J~:  
W6T&hB  
public class FileSplitterFetch extends Thread { 5KR|p Fq  
6~ `bAe`}  
+d f?N  
String sURL; //File URL (do=o&9p m  
long nStartPos; //File Snippet Start Position hhGpB$A  
long nEndPos; //File Snippet End Position H\mVK!](D  
int nThreadID; //Thread's ID %#9~V  
boolean bDownOver = false; //Downing is over Yk Pt*?,P/  
boolean bStop = false; //Stop identical 0Q>|s_  
FileAccessI fileAccessI = null; //File Access interface E+zn\v  
fJ2{w[ne  
z-5#bOABW  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0)5Sx /5'  
{ GuWBl$|+b  
this.sURL = sURL; h\d($Ki  
this.nStartPos = nStart; PEEY;x  
this.nEndPos = nEnd; Z!reX6  
nThreadID = id; ZPao*2xz  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _KVB~loT  
} :, [ !8QP  
#ya|{K  
- >I{ :#  
public void run() I%919  
{ HDyZzjgG  
while(nStartPos < nEndPos && !bStop) \STvBI?  
{ B5HdC%8/}  
vXyo  
:QV6 z*#zD  
try{ B:4qW[U#  
URL url = new URL(sURL); ~^~RltY  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tq[",&K  
httpConnection.setRequestProperty("User-Agent","NetFox"); \)ZX4rs{8  
String sProperty = "bytes="+nStartPos+"-"; t[,T}BCy.  
httpConnection.setRequestProperty("RANGE",sProperty); (B,t 1+%  
Utility.log(sProperty); *u'`XRJU/  
Wmxw!   
$S8bp3)  
InputStream input = httpConnection.getInputStream(); +A?+G  
//logResponseHead(httpConnection); Q 02??W  
$Wzv$4;  
[KI`e  
byte[] b = new byte[1024]; Ko|xEz=  
int nRead; OW}j4-~wL  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zl 0^EltiU  
{ ;n{j,HB  
nStartPos += fileAccessI.write(b,0,nRead); dG>Wu o  
//if(nThreadID == 1) 8/?uU]#Q  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \Ntdl:fSw  
} }|"*"kxi!  
)^S^s >3  
b[o"Uq@8?  
Utility.log("Thread " + nThreadID + " is over!"); :YXQ9/iRr  
bDownOver = true; Qfu*F}  
//nPos = fileAccessI.write (b,0,nRead); 2G5!u)  
} <VR&= YJ  
catch(Exception e){e.printStackTrace ();} G!LNP&~  
} j_uY8c>3\q  
} *2 $m>N  
#'Y6UGJ\n  
a 8hv.43  
//打印回应的头信息 7WfirRM  
public void logResponseHead(HttpURLConnection con) 9Q7cUoxY  
{ `[` *@O(y  
for(int i=1;;i++) A;j$rGx  
{ FJ,\?ooGf  
String header=con.getHeaderFieldKey(i); *5'6 E'  
if(header!=null) >\x_"oR  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G%8)6m'3  
Utility.log(header+" : "+con.getHeaderField(header)); rn[}{1I33Q  
else 4i\aW:_'i  
break; ^=Tu>{uD  
} h8= MVh(I  
} <T.#A8c  
C\ 2 >7  
UFAMbI  
public void splitterStop() \v P2B  
{ 27 YLg c  
bStop = true; *o\Y~U-so  
} l)PFzIz=V  
vua1iN1  
aco}pXz  
} l^y?L4hg)  
<_{4-Q>S3#  
fRa-bqQ  
/* u3i| }`  
**FileAccess.java "ko?att~  
*//文件访问(定位,写) M3;v3 }z<-  
package NetFox; ? ]:EmP  
import java.io.*; g yH7((#i  
sEJ;t0.LX  
k#:@fH4{PA  
public class FileAccessI implements Serializable{ Hs`#{W{.  
!_z<W~t"  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /Zeg\}/4[  
RandomAccessFile oSavedFile; zmfRZ!Eh  
long nPos; %)hIpxOrX  
Or#+E2%1E  
vH?+JN"A  
public FileAccessI() throws IOException pT;-1c%:  
{ c>WpOZ,  
this("",0); 'UXj\vJ3E  
} -G<2R"Q#N  
B/9<b{6  
IU'!?XVo  
public FileAccessI(String sName,long nPos) throws IOException N" Jtg@w  
{ MHr0CYyb.  
oSavedFile = new RandomAccessFile(sName,"rw"); am'p^Z @  
this.nPos = nPos; `\4JwiPo  
oSavedFile.seek(nPos); Wh'_ slDH+  
} ;GgQ@s@  
;aK !eD$  
u388Wj   
public synchronized int write(byte[] b,int nStart,int nLen) gQpD]p%k  
{ mA] 84zO  
int n = -1; +?5Uy*$  
try{ hzuMTKH9  
oSavedFile.write(b,nStart,nLen); ND55`KT4  
n = nLen; "J[i=~(  
} : ` 6$/DK  
catch(IOException e) id#k!*$7  
{ pJ$N@ID  
e.printStackTrace (); I bv_D$cT  
} At[n<8_|  
mp+\!  
Z/6'kE{l  
return n; K'{W9~9Lq  
} LnI{S{]wDh  
~q]|pD"\K|  
:a f;yu  
} Q1ABnacR  
}2BH_  2  
[>M*_1F  
/* [,o5QH\Etq  
**SiteInfoBean.java v1X&p\[d  
*/ z^a!C#IX  
package NetFox; ),y!<\oQ  
rm)SfT<  
!8"$d_=h  
public class SiteInfoBean { JX\T {\m#  
 10l1a4  
QC\g%MVG  
private String sSiteURL; //Site's URL rPo\Dz  
private String sFilePath; //Saved File's Path {7Gx9(  
private String sFileName; //Saved File's Name )(?UA$"  
private int nSplitter; //Count of Splited Downloading File }KaCf,O  
{Z?$Co^R  
+.gf]|  
public SiteInfoBean() sQ>B_Y!  
{//nSplitter的缺省值为5 b!^M}s6  
//default value of nSplitter is 5 RZ<+AX9R  
this("","","",5); %+7T9>+  
} e0|_Z])D  
UP~WP@0F  
1hMX(N&|  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =~W0~lxX  
{ -|k&L}\OB0  
sSiteURL= sURL; S4{Mu(^xT  
sFilePath = sPath; z7@(uIl=X  
sFileName = sName; |B1; l<|`  
this.nSplitter = nSpiltter; vU8FHVytV  
"3Xv%U9@  
<9d-Hz  
} ,yM}]pwlB  
C$'D]fX  
bU:}ZO^S  
public String getSSiteURL() 2Pem%HE~P  
{ oXQ<9t1(  
return sSiteURL; d Ik8TJ  
} fOK+DT~  
k binf  
:p\(y  
public void setSSiteURL(String value)  zU4V^N'  
{ 6HEqm>Yau  
sSiteURL = value; Ha=_u+@  
} 'd2qa`H'}B  
} :RT,<  
%EJ\|@N:  
public String getSFilePath() pT3X/ ra  
{ {w |dM#  
return sFilePath; &sZ9$s:(^  
} _X,[]+ziu%  
/slm ]'  
*gM,x4Y  
public void setSFilePath(String value) EI=Naq  
{ [w&#+h-q  
sFilePath = value; O2`oe4."vd  
} JGk3 b=K  
f.aB?\"f6  
?u_gXz;A  
public String getSFileName() #K :-Bys5v  
{ $S6HZG:N  
return sFileName; }XGMa?WR  
} BrlzN='j}  
cQ3W;F8|n  
0|fb< "  
public void setSFileName(String value) n) _dH/"  
{ E(QZ!'%K+m  
sFileName = value; ? fbgU  
} FG DGWcRw~  
(B _7\}v|_  
"EcX_>  
public int getNSplitter() |+Hp+9J  
{ ~ Ho{p Oq  
return nSplitter; %Y cxC0S[  
} kf%&d}2to  
"*++55  
T3USNc51  
public void setNSplitter(int nCount) .>mH]/]m  
{ ]>R`;"(  
nSplitter = nCount; JmU<y  
} g.B%#bfg  
} e/"yGQu  
X q}Ucpj  
HE#,(;1i  
/* lZ|L2Yg3uB  
**Utility.java ||-nmOy  
*/ Vs#"SpH{'  
package NetFox; z-EwXE  
B ~fSMB6h  
n S_Ta  
public class Utility { @~m=5C  
<Rcu%&;i  
[[R7~.;  
public Utility() !dU9sB2  
{ ;y>S7n>n:  
o"rq/\ovv  
'|vD/Qf=&  
} Tub1S v>J  
"w}-?:# j  
//线程睡眠 f4]N0  
public static void sleep(int nSecond) "z rA``  
{ E,{GU  
try{ {>8Pl2J  
Thread.sleep(nSecond); )y9;OA  
} Y/. AUN Z  
catch(Exception e) &+mV7o  
{ V ]79vC  
e.printStackTrace (); ifXW  
}  !M  
} Ye9Y^+-  
x(L(l=^"  
//日志 , N53Iic  
public static void log(String sMsg) &4,WG  
{ |u@+`4o  
System.err.println(sMsg); :.*HQt9N  
} ""co6qo#>  
QX[Djz0H8  
n[!;yO  
public static void log(int sMsg) 6cM<>&e  
{ \)ip>{WG  
System.err.println(sMsg); = 96G8hlT  
} Zp?4uQ)[W  
} C:]s;0$3'9  
8wr8:( Y$  
\gLxC  
/* k`Nyi )AGe  
**TestMethod.java D^Te%qnW  
*/ w/ TKRCO3  
package NetFox; l , ..5   
qu_)`wB  
u*2fP]n  
public class TestMethod { ]kx-,M(  
P0^c?s"I  
8{dEpV*  
public TestMethod() ;HDZ+B  
{ ///xx/weblogic60b2_win.exe S}[l*7  
try{ 3y99O $EAc  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KU-'+k2s;p  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 11@]d ]v ,  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q]@c&*_|  
fileFetch.start(); <3A0={En  
} 4'',6KJ@  
catch(Exception e){e.printStackTrace ();} yL6^\x  
C,/O   
H@GE)I>^@  
} o\Uu?.-<  
1BJ<m5/1%  
6B0# 4Qrv  
public static void main(String[] args) Gav"C{G  
{ H$!+A  
new TestMethod(); Z7fg 25  
} qj&b o  
} owvS/"@  
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