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http断点续传简单实现(java)

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/* Ys.GBSlHG  
**SiteFileFetch.java >,Y+ 1  
*/ r0nnmy]{d  
package NetFox; R?1Z[N  
import java.io.*; b"\lF1Nf&o  
import java.net.*; C[fefV9g2  
jOCV)V9}  
a( ~X  
public class SiteFileFetch extends Thread { bj`GGxzOb  
v2tVq_\AMx  
J#Q>dC7  
SiteInfoBean siteInfoBean = null; //文件信息Bean 1>[#./@  
long[] nStartPos; //开始位置 *04}84?:  
long[] nEndPos; //结束位置 &IXmy-w  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 g}R#0gkdk}  
long nFileLength; //文件长度 V0D&bN*  
boolean bFirst = true; //是否第一次取文件 ,8zJD&HMx  
boolean bStop = false; //停止标志 GH':Yk  
File tmpFile; //文件下载的临时信息 T}{zh  
DataOutputStream output; //输出到文件的输出流 z#Qe$`4&  
R<f F ^^  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) _8r'R  
public SiteFileFetch(SiteInfoBean bean) throws IOException [^GBg>k  
{ &_]G0~e  
siteInfoBean = bean; 8+Tv@  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); !\|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 9{3_2CIL  
if(tmpFile.exists ()) [f\Jcjc  
{ IG|u;PH<  
bFirst = false; <V)z{uK  
read_nPos(); NA$)qX_  
} u`wD6&y*  
else QDj%m%Xd  
{ c|3oa"6T>  
nStartPos = new long[bean.getNSplitter()]; )-"<19eu  
nEndPos = new long[bean.getNSplitter()]; ]35`N<Ac  
} MA_YMxP.'  
M._E$y,5  
"c} en[  
CT_tJ  
} v6DjNyg<x  
4pMp@ b  
 RSj8T<  
public void run() /tG as  
{ S@!_{da  
//获得文件长度 q{G8 Po$z'  
//分割文件 }fk3a9j9u  
//实例FileSplitterFetch gFuK/]gzI  
//启动FileSplitterFetch线程 QxPPgn7'  
//等待子线程返回 VOC$Kqg;  
try{ @C^x&Sjm  
if(bFirst) SVZ@'X\[M  
{ F#yn'j8  
nFileLength = getFileSize(); O13]H"O_  
if(nFileLength == -1) {/)i}V#RE  
{ vN v'%;L  
System.err.println("File Length is not known!"); H!0m8LCnb  
} Z&?4<-@6\p  
else if(nFileLength == -2) l z"o( %D  
{ %CYo, e  
System.err.println("File is not access!"); %}H 2  
} 6:S, {@G  
else /Z]nV2$n)V  
{ I9L3Y@(f6m  
for(int i=0;i<nStartPos.length;i++) (e5Z^9X  
{ ^w%%$9=:r  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); b3_P??yp  
} 3n)Kzexh  
for(int i=0;i<nEndPos.length-1;i++) ugXDnM[S%  
{ *tT}N@<%  
nEndPos = nStartPos[i+1]; PA803R74  
} .7 )oWd!  
nEndPos[nEndPos.length-1] = nFileLength; 9W(&g)`  
} \>*.+?97  
} ud(0}[  
w%TrL+v  
 |15!D  
//启动子线程 iku*\,6W  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Gjq7@F'  
for(int i=0;i<nStartPos.length;i++) 2o9B >f&g  
{ CG@Fn\J  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 49>b]f,Vc  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4a& 8G  
nStartPos,nEndPos,i); XXX y*/P  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ld#x'/  
fileSplitterFetch.start(); M]k Q{(  
} xMQ>,nZ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %{IgY{X  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); # "c'eG0  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6ERMn"[_w  
nEndPos = " + nFileLength); #wT6IU1  
// fileSplitterFetch[nPos.length-1].start(); x&J\swN9  
&QD)1b[U  
Z~h6^h   
//等待子线程结束 2!}F+^8'P  
//int count = 0; 3 eF c  
//是否结束while循环 Hmm0H6&u  
boolean breakWhile = false; 'MX|=K!C  
0+qC_ISns  
o:cTc:l)  
while(!bStop) ^/}4M'[w  
{ cy(w*5Upu  
write_nPos(); 0U/[hG"DKN  
Utility.sleep(500); KyT=:f V  
breakWhile = true; zd8A8]&-  
a;KdkykG  
|S).,B  
for(int i=0;i<nStartPos.length;i++) XZ8rM4 ]  
{ U!Zj%H1XQ0  
if(!fileSplitterFetch.bDownOver) B*}]'  
{ VHqoa>U,*  
breakWhile = false; l=T;hk  
break; |.RyF@N`T  
} aY,Bt  
} qHgtd+ I  
if(breakWhile) 4qE4 i:b  
break; kmTYRl )j  
i)(G0/:  
2DsP "q79k  
//count++; ?5ZvvAi  
//if(count>4) gQSVPbzK  
// siteStop(); aB (pdW4  
} uUx7>algF  
>G"fMOOkW  
EpRn,[  
System.err.println("文件下载结束!"); QPLWRZu@  
} h]~FYY  
catch(Exception e){e.printStackTrace ();} aqqo>O3 s  
} re%XaL  
Hicd -'  
;Q q_  
//获得文件长度 r{d@74  
public long getFileSize() CeOA_M  
{ W3Ee3  
int nFileLength = -1; S9$,.aq  
try{ VFF5 Tp  
URL url = new URL(siteInfoBean.getSSiteURL()); j+-`P5  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TlyBpG=p  
httpConnection.setRequestProperty("User-Agent","NetFox"); Y ~I>mc]  
1Zp/EYWa{  
E <j=5|0t  
int responseCode=httpConnection.getResponseCode(); Y R~e_cA:  
if(responseCode>=400) :ln| n6X  
{ Z R=[@Oi  
processErrorCode(responseCode); 4<}@hk Y  
return -2; //-2 represent access is error 3}phg  
} z8S]FpM6  
gn/]1NNfR  
O^./) #!#  
String sHeader; SfPQ;s'  
,vvfk=-  
8Vn   
for(int i=1;;i++)  (t5y$b c  
{ _8K8Ai-~.>  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iNi1+sm  
//Utility.log(in.readLine()); LzLJ6A>;R  
sHeader=httpConnection.getHeaderFieldKey(i); Bx}"X?%S  
if(sHeader!=null) _nzq(m1@  
{ ,MJddbcg  
if(sHeader.equals("Content-Length")) _(gkYJ+MK  
{ # SCLU9-  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &,PA+#  
break; .WN&]yr,  
} |zfFB7}v  
} y_W?7 S  
else @VOegf+N  
break; ^J^~5q8  
} ?xMTO  
} !.V_?aYi8  
catch(IOException e){e.printStackTrace ();} O"TVxP:  
catch(Exception e){e.printStackTrace ();} 2<n 18-|OQ  
OPq|4xu  
,-EN{ed  
Utility.log(nFileLength);  Br s}  
>m%TUQ#%  
Zp_j\B  
return nFileLength; RaTNA W)v>  
} NW0se DL  
yVn%Bz' [  
=z9,=rR4  
//保存下载信息(文件指针位置) IRk)u`  
private void write_nPos() j?$B@Zk  
{ rDwd!Jet  
try{ [{xY3WS  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Fq+Cr?-  
output.writeInt(nStartPos.length); xA:;wV  
for(int i=0;i<nStartPos.length;i++) |p+FIr+  
{ rttKj{7E  
// output.writeLong(nPos); [-Y~g%M  
output.writeLong(fileSplitterFetch.nStartPos); ,*lns.|n  
output.writeLong(fileSplitterFetch.nEndPos); 2w1Mf<IXPo  
} 5Y`4%*$  
output.close(); DtGkhq;  
} W2$rC5|  
catch(IOException e){e.printStackTrace ();} BIx*(  
catch(Exception e){e.printStackTrace ();} 8,+T[S  
} buzpmRoN)  
'CqAjlj  
RB""(<  
//读取保存的下载信息(文件指针位置) <T.R%Jys  
private void read_nPos() 6-?/kY6  
{ "3Dnp?gB  
try{ 3kGg;z6  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Dvz 6 E  
int nCount = input.readInt(); VY~*QF~P  
nStartPos = new long[nCount]; J'=s25OWU  
nEndPos = new long[nCount]; c; .y  
for(int i=0;i<nStartPos.length;i++) ]moBVRd  
{ 3bC-B!{;g  
nStartPos = input.readLong(); d@JavcR  
nEndPos = input.readLong(); j;j~R3B  
} fWfhs}_  
input.close(); 13 JG[,w  
} ;2fzA<RkK  
catch(IOException e){e.printStackTrace ();} Edh9=sxL  
catch(Exception e){e.printStackTrace ();} {nA+-=T  
} j/T@-7^0  
T=V{3v@zs  
|yOIC,5[JW  
private void processErrorCode(int nErrorCode) :|I"Em3R  
{ *Y53b Z  
System.err.println("Error Code : " + nErrorCode); 3~WI3ZIR  
} K|~ !oQ  
q(s0dkrj  
&2@Rc?!6_P  
//停止文件下载 !m_y@~pV#u  
public void siteStop() ~^Ga?Q_  
{ >c:nr&yP  
bStop = true; F!C<^q~!  
for(int i=0;i<nStartPos.length;i++) Op 9+5]XF  
fileSplitterFetch.splitterStop(); pG* W>F  
z:dW'U?1  
,e`n2)  
} V~o'L#a  
} #gf0*:p  
//负责部分文件的抓取 oM#+Z qP  
**FileSplitterFetch.java u,YmCEd_V  
*/ 8h}1t4k  
package NetFox; `N}'5{I  
9*n?V;E  
j9Z1=z  
import java.io.*; 6+>X`k%D  
import java.net.*; yg|yoL'g  
i}<fg*6@E  
0H}O6kU  
public class FileSplitterFetch extends Thread { 4.kn , s  
M M @&QaK  
rO1N@kd/  
String sURL; //File URL DYZk1  
long nStartPos; //File Snippet Start Position gK *=T  
long nEndPos; //File Snippet End Position 5X]f}6kT  
int nThreadID; //Thread's ID rF?QI*`Y(  
boolean bDownOver = false; //Downing is over |w_l~xYV)  
boolean bStop = false; //Stop identical ct(euPU  
FileAccessI fileAccessI = null; //File Access interface 6@(o8i   
+'[*ikxD=g  
11A;z[Zk  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g6 SZ4WV  
{ sFgsEKs  
this.sURL = sURL; 8j ky-r  
this.nStartPos = nStart; uAk>VPuuZ  
this.nEndPos = nEnd; ?6MUyH]a  
nThreadID = id; 9I1`*0A  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j{ri]?p  
} RSjcOQ8&.w  
4>HQ2S{t  
!Xq5r8]  
public void run() AQ"rk9Z  
{ gd]k3XN$f  
while(nStartPos < nEndPos && !bStop) -gb@BIV#  
{ ^v3J ld  
v)zxQuH]^  
\/ Zo*/  
try{ &y3;`A7,  
URL url = new URL(sURL); q?0&0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1yc$b+TH  
httpConnection.setRequestProperty("User-Agent","NetFox"); `[_p,,}Ir  
String sProperty = "bytes="+nStartPos+"-"; %~Wr/TOt+  
httpConnection.setRequestProperty("RANGE",sProperty); 7$L*nf  
Utility.log(sProperty); E|VTbE YG  
8*]dA ft  
lb}:! Y  
InputStream input = httpConnection.getInputStream(); [F27i#'I]  
//logResponseHead(httpConnection); 4 `}6W>*R  
niPqzi  
3XUie;*`  
byte[] b = new byte[1024]; Z+FhI^  
int nRead; Fdx4jc13w  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _#<7s`i  
{ (gutDUO;  
nStartPos += fileAccessI.write(b,0,nRead); (. $e@k=  
//if(nThreadID == 1) r,GgMk  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [&p/7  
}  |L  <  
#J$z0%P  
|A)a ='Ap  
Utility.log("Thread " + nThreadID + " is over!"); [Z]CBEE  
bDownOver = true; ~.S/<:`U  
//nPos = fileAccessI.write (b,0,nRead); $|19]3T@Z  
} 3HndE~_C&  
catch(Exception e){e.printStackTrace ();} lp1GK/!s  
} wr6(C:  
} #<w2xR]:  
RE;)#t?K  
G|UeR=/  
//打印回应的头信息 @ `SlOKz!=  
public void logResponseHead(HttpURLConnection con) 3`njQvI\  
{ uHt@;$9A  
for(int i=1;;i++) ~2XiKY;W?  
{ .`h:1FP 8  
String header=con.getHeaderFieldKey(i); OL@' 1$/A  
if(header!=null) 2 3A)^j  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S <++eu  
Utility.log(header+" : "+con.getHeaderField(header)); sFRQFX0XoY  
else Q3LScpp  
break; l]5!$N*  
} ((fFe8Rn)q  
} C7MCMM|S  
4+N9Ylh  
,LDdL  
public void splitterStop() #4^D'r>pJ  
{ ~H626vT37  
bStop = true; )dRB I)P  
} <TEDs4 C  
8H{9  
8-Z|$F"  
} >td\PW~X  
)KN]"<jB  
h]^= y.Q  
/* t,yMO  
**FileAccess.java D{]9s  
*//文件访问(定位,写) $4>x4*  
package NetFox; E vD g{M}  
import java.io.*; dYp} R>+  
 BbNl:`  
t[bZg9;  
public class FileAccessI implements Serializable{ NKu*kL}W=  
X}]g;|~SN  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 k{+ Gv}Y  
RandomAccessFile oSavedFile; m^1'aO_;q  
long nPos; 9Qc=D"'  
~qb-uT\(99  
24d{ol)  
public FileAccessI() throws IOException @Yzb6@g"  
{ y6Ea_v  
this("",0); 8G_KbS  
} +(o]E3  
T=T1?@2C  
:>, m$XO  
public FileAccessI(String sName,long nPos) throws IOException ap.L=vn  
{ [gE2;J0*  
oSavedFile = new RandomAccessFile(sName,"rw"); d>`s+B9K0  
this.nPos = nPos; Jgzg[6  
oSavedFile.seek(nPos); h1QrFPQnu  
} 7j{63d`2  
gib;> nuBK  
ne'Y{n(8%  
public synchronized int write(byte[] b,int nStart,int nLen) Jnq}SUev  
{ .OvH<%g!.  
int n = -1; NAEAvXj  
try{ ?lQ-HOAw  
oSavedFile.write(b,nStart,nLen); h Ap(1h#m  
n = nLen; 2@$`xPg  
} r[kmgPld  
catch(IOException e) 3rVWehCv  
{ Hu7WU;w  
e.printStackTrace (); "v5jYz5M  
} 9rM6kLD  
d?1[xv;  
9 IY1"j0O  
return n; |F52)<\  
} C3e0d~C  
#w]@yL]|is  
;Qdw$NuW  
} Te&5IB-  
~#9(Q  
!l#n.Fx&3  
/* FKkL%:?  
**SiteInfoBean.java ,Q>wcE6v  
*/ fdzaM&  
package NetFox; 1<&nHFJ;[  
t,R4q*  
Q`[J3-Q*{  
public class SiteInfoBean { Iq: G9M  
iig@$ i#  
($^=f}+  
private String sSiteURL; //Site's URL $}Ky6sBnvO  
private String sFilePath; //Saved File's Path vS+E`[  
private String sFileName; //Saved File's Name tJZ3P@ L  
private int nSplitter; //Count of Splited Downloading File > R2o7~  
gjex;h  
1A;f[Rze  
public SiteInfoBean() cR/z;*wr7  
{//nSplitter的缺省值为5 OE_A$8L  
//default value of nSplitter is 5 ];au! _o  
this("","","",5); ?<eH!MHF  
} * odwg$  
kU[#. y=%p  
? EXYLG  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fs%l j_t  
{ )w&k&TY4H  
sSiteURL= sURL; R{SN.%{;  
sFilePath = sPath; K._* ~-A  
sFileName = sName; gqQ"'SRw  
this.nSplitter = nSpiltter; QAKA3{-(  
Xmaj7*f>p  
\tZZn~ex  
} WeRX~  
kJG0X%+w  
0N4+6k|  
public String getSSiteURL() m<| *  
{ y?yWM8  
return sSiteURL; @DA.$zn&  
} =/L;}m)7  
$VyH2+ jC  
V [r1bF  
public void setSSiteURL(String value) Pvu*Y0_p  
{ CWS&f g%o{  
sSiteURL = value; ca!DZ%y  
} 4Q n5Mr@<  
2g:V_%  
)6 [d'2  
public String getSFilePath() #a=~a=c(^  
{ Z2hIoCT  
return sFilePath; S|v")6  
} (b>B6W\&  
x#,nR]C  
"qvJ-Y  
public void setSFilePath(String value) W<s5rMx  
{ <c$K3  
sFilePath = value; Q=Y1kcTOn  
} UfAN)SE"  
Mg76v<mv<  
?wYvBFRn7"  
public String getSFileName() K1*]6x,  
{ 3lD1G~  
return sFileName; |\_d^U &`  
} fPu,@ L  
8^|lsB}x?  
OXCf  
public void setSFileName(String value) _vgFcE~E@  
{ W2G@-`,  
sFileName = value; B gB]M3Il  
} z;d]=PT  
h,%b>JFo  
r&?i>.Kz8  
public int getNSplitter() z9 )I@P"  
{ L>Soj|WUy(  
return nSplitter; U|}Bk/0.  
} JVk"M=c  
-cW 'g  
dpWBY3(7a  
public void setNSplitter(int nCount) l/F'W}  
{ B2DWSp-8*  
nSplitter = nCount; K\a=bA}DG  
} 8KhE`C9z  
} `oUuAL  
mhZ60RW  
{Mx3G*hr  
/* 8O0E;6b  
**Utility.java -^+!:0';  
*/ NT}r6V(Aju  
package NetFox; ~99DE78  
:M'V**A(  
tV5U z&:b  
public class Utility { I? o)X!  
(#`1[n+b`x  
v?en-,{A  
public Utility() r^,XpRe&M  
{ j9G1  _  
a2tRmil  
:`w'}h7m  
} NHjZ`=J s  
C/L+gU&  
//线程睡眠 7xr@$-U  
public static void sleep(int nSecond) w;Jby  
{ N akSIGm  
try{ fXJbC+  
Thread.sleep(nSecond); [TFd|ywn  
} 7(oX 1hN  
catch(Exception e) A:-r 2;xB  
{ quEP"  
e.printStackTrace (); G^Q8B^Lg  
} C_~hX G  
} X|iWnz+^  
':jsCeSB  
//日志 9;*-y$@  
public static void log(String sMsg) &>]c"?C*  
{ ;5(ptXX1W  
System.err.println(sMsg); 8vL2<VT;  
} /PuN+M  
Sl RQi:  
cB ,l=/?  
public static void log(int sMsg) vm y?8E6+  
{ bb ]r  
System.err.println(sMsg); 6bXR?0$*M.  
} ToVi;  
} Z+G.v=2q<  
zj9)vr`7  
/\0 rRT  
/* WK<:(vu.  
**TestMethod.java 6pCQP c*A  
*/ =K ctAR;  
package NetFox; 5RysN=czA  
<@puWm[p  
>m-VBo  
public class TestMethod { {hmC=j  
[_pw|BGp  
MY]<^/Q  
public TestMethod() 6 ?C|pO  
{ ///xx/weblogic60b2_win.exe ?mCino  
try{ X?8EPCk  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >A RZ=x[  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +Kz baBK  
SiteFileFetch fileFetch = new SiteFileFetch(bean); `,O#r0m  
fileFetch.start(); c6@7>PM  
} %gb4(~E+N  
catch(Exception e){e.printStackTrace ();} 1K`7  
C =6.~&(  
X*^^W_LH.  
} $k|:V&6SV  
:p@.aD5  
&*4C{N  
public static void main(String[] args) nbECEQ:|B  
{ dpPu&m+  
new TestMethod(); ZHWxU  
} PqJB&:ZV  
} yDil  
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