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http断点续传简单实现(java)

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/* iCP~O  
**SiteFileFetch.java pISp*&  
*/ dFW.}"^c  
package NetFox; CQgcC-)ns]  
import java.io.*; *nRNg.i3D  
import java.net.*; :_xh(W+2<  
Ja|{1&J.  
px=]bALU  
public class SiteFileFetch extends Thread { n *<v]1  
.po>qb6  
jAC78n,Fi@  
SiteInfoBean siteInfoBean = null; //文件信息Bean d]SYP  
long[] nStartPos; //开始位置 oh~: ,  
long[] nEndPos; //结束位置 M&KyA  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 +Rwx% =  
long nFileLength; //文件长度 -:<lkq&/  
boolean bFirst = true; //是否第一次取文件 [|RjHGf  
boolean bStop = false; //停止标志 )K;]y-Us[  
File tmpFile; //文件下载的临时信息 };b1ahaG  
DataOutputStream output; //输出到文件的输出流 irKIy  
/7/0x ./{  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) FJ54S  
public SiteFileFetch(SiteInfoBean bean) throws IOException 1$pb (OK  
{ XN;&qR^j  
siteInfoBean = bean; [&#/|zH'j:  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Vn, >< g  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); q/PNJ#<  
if(tmpFile.exists ()) [=uIb._Wv  
{ eKG2*CV  
bFirst = false; /Vww?9U;  
read_nPos(); =:=/Gz1  
} `s"d]/85VW  
else MsOs{2 )2  
{ w5,Mb  
nStartPos = new long[bean.getNSplitter()]; asVX82<  
nEndPos = new long[bean.getNSplitter()]; hH>``gK  
} o6a0'vU><  
W\cjdd  
}^%xvmQ\]  
QJGKQ2^ n  
} |(%zb\#9  
QkQ!Ep(  
:Ht; 0|[H  
public void run() )nfEQ)L;h}  
{ $IX\O  
//获得文件长度 O )d[8jw"  
//分割文件 * F4UAQzYb  
//实例FileSplitterFetch nP3  E  
//启动FileSplitterFetch线程 UvJ; A  
//等待子线程返回 h6v077qG  
try{ h8{(KRa6  
if(bFirst) ezm&]F`  
{ n3KI+I%nQ  
nFileLength = getFileSize(); *O~e T  
if(nFileLength == -1) = QO g 6  
{ 5(m(xo6  
System.err.println("File Length is not known!"); "ju'UOcS/  
} iE].&>w  
else if(nFileLength == -2) F@YKFk+a  
{ 646JDX[o  
System.err.println("File is not access!"); g)"gw+ZFc  
} 6%Mt  
else 12UD19!  
{ Cu;5RSr2Z  
for(int i=0;i<nStartPos.length;i++) v,@F|c?_S  
{ ?-)I+EAnE  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]?+{aS-]?k  
} jgv`>o%<W  
for(int i=0;i<nEndPos.length-1;i++) ;C.S3}  
{ i^msjA  
nEndPos = nStartPos[i+1]; 8\.b4FNJ  
} Yk!/ow@.  
nEndPos[nEndPos.length-1] = nFileLength; tc+WWDP#"  
} I\O\,yPhhP  
} a_~=#]a  
k[j90C5  
zUJZ`seF  
//启动子线程 c9"r6j2m5  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;&b.T}Nf06  
for(int i=0;i<nStartPos.length;i++) Q\ppfc{,  
{ C1kYl0 zR[  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <ABX0U[*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ifc]K?  
nStartPos,nEndPos,i); +0Q,vK#j^  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fh$slow4!  
fileSplitterFetch.start(); yLE7>48  
} M5357Q  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NPa\Cg[  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); co8"sz0(U  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SRIA*M.B}  
nEndPos = " + nFileLength); ypOLp SYk  
// fileSplitterFetch[nPos.length-1].start(); ^TY ;Zp  
"Jq8?FoT  
B;>{0 s  
//等待子线程结束 K<`osdp=&  
//int count = 0; : 18KR*;p  
//是否结束while循环 !9Z r;K~\  
boolean breakWhile = false; m0n)dje  
r0;:t   
YyAJ m^o  
while(!bStop) "TyJP[/  
{ bNs4 5hDP  
write_nPos(); }@ Z56  
Utility.sleep(500); V" \0Y0  
breakWhile = true; *iBTI+"]  
H,3\0BKk  
OJ|r6  
for(int i=0;i<nStartPos.length;i++) 8BOZh6BV  
{ ,l YE  
if(!fileSplitterFetch.bDownOver) c/N@zum,{  
{ "5R~(+~<@  
breakWhile = false; sV"UI  
break; i<kD  
} _|[UI.a  
} ^hNgm.I  
if(breakWhile) ajR%c2G;  
break; IJYL s  
J]l rS  
nRL. ppUI  
//count++; x+ncc_2n&D  
//if(count>4) M5nWVK7c  
// siteStop(); B~]5$-  
} Qd}m`YW-f$  
7w,FX.=;cv  
DI+]D~N  
System.err.println("文件下载结束!"); Unj.f>U  
} voP7"Dl[  
catch(Exception e){e.printStackTrace ();} ]^':Bmq  
} |F,R&<2  
]H-S, lmV  
%~L>1ShtU  
//获得文件长度 gb ^?l~SS  
public long getFileSize() MFTk qbc  
{ ;<yd^Xs  
int nFileLength = -1; 'o|30LzYgQ  
try{ @1.QEyXG  
URL url = new URL(siteInfoBean.getSSiteURL()); SDu#Yt&mhh  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q_* "SRz  
httpConnection.setRequestProperty("User-Agent","NetFox"); S5~VD?O,  
HEA#bd\  
,@1p$n  
int responseCode=httpConnection.getResponseCode(); Dd;Nz  
if(responseCode>=400) ];.pK  
{ '!l 1=cZD  
processErrorCode(responseCode); 4wC+S9I#E^  
return -2; //-2 represent access is error l^ZI* z7N  
} il|1a8M2~  
~P~  
M@ed>.  
String sHeader; q0f3="  
^O^l(e!3  
:RoBl3X=  
for(int i=1;;i++) y_\p=0t8  
{ (WJ${OW  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ? A(QyaKz  
//Utility.log(in.readLine()); nKW*Y}VO  
sHeader=httpConnection.getHeaderFieldKey(i); x77l~=P+!  
if(sHeader!=null) fP.F`V_Y  
{ PV|uPuz  
if(sHeader.equals("Content-Length")) ^Ge+~o?x  
{ T]2q?; N  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :'#TCDlOb  
break; ]-ZEWt6lsc  
} me[DmiM,  
} 7AYd!n&S  
else $O9^SB  
break; Fx-8M!  
} !9Aaj<yxm  
} T&Lb<'f  
catch(IOException e){e.printStackTrace ();} ^i:`ZfA#  
catch(Exception e){e.printStackTrace ();} 8_T6_jL<  
!\&;h  
sC9&Dgkk  
Utility.log(nFileLength); TMY d47  
I\YV des#  
PO 6&bIr  
return nFileLength; h;6lK$!c  
} y|'SXM  
`jwa<N4e@  
7o8{mp'_  
//保存下载信息(文件指针位置) V<Z[ nq  
private void write_nPos() s kg*  
{ ]X I*Wsn  
try{ [IK  )  
output = new DataOutputStream(new FileOutputStream(tmpFile)); R: l&2k@  
output.writeInt(nStartPos.length); 76u&EG%  
for(int i=0;i<nStartPos.length;i++) `uC@nJ  
{ Pp )3(T:  
// output.writeLong(nPos); 4;2< ^[M  
output.writeLong(fileSplitterFetch.nStartPos); o6V}$wT3J  
output.writeLong(fileSplitterFetch.nEndPos); cJ54s}  
} #dM9pc jh  
output.close(); ) /z@vY  
} Mn)@{^  
catch(IOException e){e.printStackTrace ();} mdRU^n  
catch(Exception e){e.printStackTrace ();} aH^RoG}  
} &^W|iXi#  
wE~V]bmtW  
;qrB\j"  
//读取保存的下载信息(文件指针位置) Z)jw|T'X  
private void read_nPos() {mAU3x  
{ i&VsW7  
try{ _cXqAo  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qh`t-  
int nCount = input.readInt(); XLH0 ;+CL{  
nStartPos = new long[nCount]; {GC?SaK  
nEndPos = new long[nCount]; F7Zwh5W  
for(int i=0;i<nStartPos.length;i++) ,_Z+8  
{ j ?MAED  
nStartPos = input.readLong(); :_O%/k1\@  
nEndPos = input.readLong(); ;<leKcvhQ&  
} Q=]w !I\  
input.close(); 0}b tXh  
} ^<e.]F25M  
catch(IOException e){e.printStackTrace ();} \EVBwE,  
catch(Exception e){e.printStackTrace ();} U\Z?taXB  
} qHxqQ'ks;  
y\ a1iy  
je!-J8{  
private void processErrorCode(int nErrorCode) b,C aWg  
{ WL'P)lI5  
System.err.println("Error Code : " + nErrorCode); ]MxC_V+P`  
} {7)st W  
Z,=7Tu bR#  
Y'ow  
//停止文件下载 B[KJR?>  
public void siteStop() aoXb22]{  
{ mya_4I m  
bStop = true; ;Rv!k&Df  
for(int i=0;i<nStartPos.length;i++) /kfgx{jZ  
fileSplitterFetch.splitterStop(); ['T:ea6B  
C+TI]{t  
P'`r  
} )a-Du$kd  
} }2e? ?3  
//负责部分文件的抓取 hRCed4qA  
**FileSplitterFetch.java /Z$&pqs!  
*/ ~8]NK&J  
package NetFox; dxmE3*b`  
YxP&7oq  
7(5 4/  
import java.io.*; q}]XYys  
import java.net.*; 62Z#Y Q}x  
[Nk3|u`h  
?:)]h c  
public class FileSplitterFetch extends Thread { !1ED~3 /X  
Z /9>  
CO`_^7o9(  
String sURL; //File URL 6b:tyQ  
long nStartPos; //File Snippet Start Position sJDas,7>  
long nEndPos; //File Snippet End Position #Y4=J 6  
int nThreadID; //Thread's ID 1~PV[2a  
boolean bDownOver = false; //Downing is over :$n=$C -wp  
boolean bStop = false; //Stop identical #E&80#Z5  
FileAccessI fileAccessI = null; //File Access interface {j7uv"|X7  
A -b [>} _  
*m#Za<_Gv  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yr lf+tl  
{ AT%u%cE-  
this.sURL = sURL; 'hs2RSq  
this.nStartPos = nStart; o}$ EG  
this.nEndPos = nEnd; 2* 2wY=  
nThreadID = id; }yz (xH  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *3?'4"B{8  
} Dp':oJC  
iB498t  
3J5!oF{H  
public void run() ^3UGV*Ypk  
{ 2'W<h)m)z  
while(nStartPos < nEndPos && !bStop) wbst8 *$  
{ k<" oiCE  
[DF,^4g  
7D;cw\ |  
try{ Gy6l<:;  
URL url = new URL(sURL); } x2DT8u  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]4pkcV P  
httpConnection.setRequestProperty("User-Agent","NetFox"); @CT;g\4  
String sProperty = "bytes="+nStartPos+"-"; FGoy8+nB1M  
httpConnection.setRequestProperty("RANGE",sProperty); 8/=L2fNN[  
Utility.log(sProperty); dzDqZQY$  
z[3L2U~6  
+w+} b^4  
InputStream input = httpConnection.getInputStream(); lhBT@5Dm9  
//logResponseHead(httpConnection); pNKhc#-w  
#n#@fAY  
/|D*w^ >  
byte[] b = new byte[1024]; tQBRA/  
int nRead; , T8>}U(  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6e[VgN-s  
{ {\:{[{qF  
nStartPos += fileAccessI.write(b,0,nRead); D>LZP!  
//if(nThreadID == 1) 5Er2}KZJv,  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *^:N.&]  
} \Z+z?K O  
9T*v9d  
FSA1gAW6g  
Utility.log("Thread " + nThreadID + " is over!"); iLkZ"X.'|1  
bDownOver = true; %|^fi8!:|  
//nPos = fileAccessI.write (b,0,nRead); <OIIoB?t  
} dF2nEaN0%  
catch(Exception e){e.printStackTrace ();} 4x 8)gE   
} =fO5cA6Z  
} /!3@]xz*  
PEW=@xj2y  
'LE =6{#  
//打印回应的头信息 }n4V|f-  
public void logResponseHead(HttpURLConnection con) #~<0t(3Q  
{ /\4'ddGU  
for(int i=1;;i++) vy\RcP  
{ U 15H2-`  
String header=con.getHeaderFieldKey(i); T-U}QM_e  
if(header!=null) 'LO^<  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :gep:4&u  
Utility.log(header+" : "+con.getHeaderField(header)); 2fWTY0  
else "-vW,7y  
break; f PM8f  
} *U P@9D  
} EV*IoE$W]=  
d%V*|0c)  
tF{D= ;G  
public void splitterStop() w tiny,6  
{ i:OK8Q{VI  
bStop = true; Bg|5KOnd  
} 4X+ifZO  
Y07ZB'K  
'.81zpff  
} SAyufLEv,  
@T'i/}nl  
kNobl  
/* _s .G  
**FileAccess.java *%S"eWb  
*//文件访问(定位,写) ?B}{GL2)  
package NetFox; $h*L=t(  
import java.io.*; 8n*.).33  
<w)r`D6  
)'6DNa[y  
public class FileAccessI implements Serializable{ t+1 %RyKFB  
TjwBv6h  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^$'z!+QRM  
RandomAccessFile oSavedFile; p IU&^yX>  
long nPos; ]]oI#*c  
f]\CD<g3|E  
R' !  
public FileAccessI() throws IOException /XzH?n/{R  
{ {;:/-0s  
this("",0); IHcD*zQ  
} 9 mmCp&~Z  
ucG@?@JENm  
6 1F(<!  
public FileAccessI(String sName,long nPos) throws IOException 93` AWg/T  
{ 3v5%y '  
oSavedFile = new RandomAccessFile(sName,"rw"); G"Sd@%W(  
this.nPos = nPos; :[hgxJu+  
oSavedFile.seek(nPos); +/)#( j@  
} S|]X'f  
b-{=s +:  
(4dhuT  
public synchronized int write(byte[] b,int nStart,int nLen) TwVlg ;  
{ \<y#R~7s  
int n = -1; ?MgUY)X  
try{ 2&^]k`Aj6D  
oSavedFile.write(b,nStart,nLen); ih P|E,L=L  
n = nLen; YW60q0:  
} A8oo@z68n>  
catch(IOException e) /7t>TYip!  
{ ](wvu(y\E  
e.printStackTrace (); Ns7(j-  
} Q2F+?w;,  
o'f?YZ$.  
{:]9Q Tq  
return n;  Pyb Z)5u  
} LRb{hUt=  
p%*%n3bw  
jN6uT &{T  
} ~==>pj  
@EnuJe  
n=c 2K c  
/* ]jmL]Ny^  
**SiteInfoBean.java 5`gQ~   
*/ e0T34x'  
package NetFox; vfE6Ggz  
ysQ,)QoiR{  
 f-E( "o  
public class SiteInfoBean { t 0|!(3  
5[YDZ7g"~  
fM^qQM[lG  
private String sSiteURL; //Site's URL PSZL2iGj9V  
private String sFilePath; //Saved File's Path NR5oIKP?  
private String sFileName; //Saved File's Name qx4I_%  
private int nSplitter; //Count of Splited Downloading File IbP#_Vt  
|,!IZ- th  
8$;=Uf,x  
public SiteInfoBean() ]2\VweV  
{//nSplitter的缺省值为5 _PlKhv}  
//default value of nSplitter is 5 )Ccq4i  
this("","","",5); pXtXjb  
} j{9D{  
Y! gCMLL  
8F&=a,ps[  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qIIv6''5@  
{ h?8]C#6^  
sSiteURL= sURL; }9W4"e2)  
sFilePath = sPath; ?l^1 *Q,  
sFileName = sName; zN"J}r:  
this.nSplitter = nSpiltter; Ko&>C_N  
@)4]b+8Z  
$}jssnoU  
} YtfVD7m  
j&Wl0  
>w^YO25q  
public String getSSiteURL() k+8q{5>A<  
{ @vrV*!  
return sSiteURL; s! }ne"&0  
} KNLfp1!  
nEkR1^30  
e[ /dv)J  
public void setSSiteURL(String value) Yo("U8:XX  
{ Vy938qX   
sSiteURL = value; <-D0u?8  
} w$`5g  
e^[H[d.WMC  
1PP $XJtyD  
public String getSFilePath() ~ ArP9 K "  
{ HO}Hh[{V9  
return sFilePath; 2g>SHS@1>  
} ~(IB0=A{v  
i2&ed_h<?  
_cJ2\`M  
public void setSFilePath(String value) -cSP _1  
{ LM-J !44  
sFilePath = value; hijgF@  
} GrAujc5|  
p n.T~"%  
'_/Bp4i  
public String getSFileName() fmiz,$O4?  
{ x>*Drm 7  
return sFileName; v!ujj5-$I  
} uec!RKE  
x\s|n{  
^,;z|f'% *  
public void setSFileName(String value) Tp_L%F  
{ KFvQ  
sFileName = value; %d(^d  
} .%Ta]!0  
X~<("  
*EZHJt9  
public int getNSplitter() e*;c(3>(  
{ ulkJR-""&  
return nSplitter; (Xq)py9  
} )Ib<F 7v  
*i- _6s  
cg m~>  
public void setNSplitter(int nCount) L.1_(3NG  
{ ]b%Hy  
nSplitter = nCount; Wr3mQU  
} [I$ BmGQ  
} 8qu2iPOcZ  
}= 6'MjF]  
0VGPEKRh  
/* L_+k12lm  
**Utility.java k'IYA#T6  
*/ }c`fW&  
package NetFox; _;~,Cgfi  
I]&#Dl/  
F;l$.9?.s  
public class Utility { OQ>x5?um  
mysetv&5  
Rx);7j/5  
public Utility() nZ@&2YPlem  
{ 8&3V#sn'  
w[ !^;#  
.$%Soyr?,  
} 'C ~ y5j  
L}}y'^(  
//线程睡眠 _&j}<K$- (  
public static void sleep(int nSecond) _`_%Y(Xat  
{ w - Pk7I  
try{ 'eJ+JM<0%  
Thread.sleep(nSecond); b D[!/'4eJ  
} M5*{  
catch(Exception e) I{lT>go  
{ 7A\~)U @  
e.printStackTrace (); #L{OV)a<  
} 3'c0#h@VD  
} jGEt+\"/QJ  
D!.+Y-+Xzu  
//日志 P~G1EK|4  
public static void log(String sMsg) ;z IP,PMM  
{ spGB)k,^  
System.err.println(sMsg); |/2y-[;:  
} yI ld75S`  
eXK o.JL  
C#t'Y*  
public static void log(int sMsg) t7m>A-I  
{ |pmZ.r  
System.err.println(sMsg); LwK+:4$  
} u)V#S:9]  
} q&Gz ]  
eOXHQjuj  
&p}$J )q  
/* 8 XICF  
**TestMethod.java $`wMX{  
*/ VsN pHQG]  
package NetFox; awOd_![c'  
mFSw@CC  
0\:(ageY?  
public class TestMethod { H'LD}\K l  
't_[dSO  
;Ww7"-=sw  
public TestMethod() ??i,Vr@)w  
{ ///xx/weblogic60b2_win.exe {2+L @  
try{ Mnz!nWhk  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~5 *5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _`I "0.B]  
SiteFileFetch fileFetch = new SiteFileFetch(bean); F@*+{1R  
fileFetch.start(); )QG<f{wS  
} qOUqs'7/]  
catch(Exception e){e.printStackTrace ();} aAA9$  
3nu^l'WQ  
+=mkCU  
} Y;e,Gq`  
sz)oZPu|  
']>Mp#j  
public static void main(String[] args) E6,4RuCK  
{ ObE,$_ k  
new TestMethod(); ;+tpvnV;]  
} GD:4"$)[o  
} >9f%@uSM$3  
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