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http断点续传简单实现(java)

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/* 1=o|[7  
**SiteFileFetch.java ={'*C7K)oK  
*/ -O&u;kh4g  
package NetFox; V%|CCrR  
import java.io.*; <d*;d3gm  
import java.net.*; &ZyZmB  
8nV#\J9  
 x&^>|'H  
public class SiteFileFetch extends Thread { *,x-}%X  
d;:H#F+ (  
7tZvz `\  
SiteInfoBean siteInfoBean = null; //文件信息Bean 1VXyn\  
long[] nStartPos; //开始位置 +,8j]<wpo  
long[] nEndPos; //结束位置 J)kH$!csi  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 yLFZo"r  
long nFileLength; //文件长度 $RAS pM  
boolean bFirst = true; //是否第一次取文件 Nj5V" c  
boolean bStop = false; //停止标志 X6h@K</c^:  
File tmpFile; //文件下载的临时信息 \}:RG^*m  
DataOutputStream output; //输出到文件的输出流 O8\>?4)  
}8lvi vR4  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 1&7~.S;km  
public SiteFileFetch(SiteInfoBean bean) throws IOException -=;V*;  
{ _R/^P>Q?  
siteInfoBean = bean; D6Q6yNE  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 5>S=f{ghFw  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ng0tNifZ;  
if(tmpFile.exists ()) pYxdE|2j  
{ 76'@}wNnw  
bFirst = false; V?[dg^*0  
read_nPos(); r:.ydr@  
} mK Ta.  
else PQ0l<]Y  
{ ,V`zW<8  
nStartPos = new long[bean.getNSplitter()]; 4hQ.RO  
nEndPos = new long[bean.getNSplitter()]; \N|ma P  
} # .j[iN :+  
JXhHitUD  
jWUpzf)q=T  
}piDg(D  
} +KcD Y1[  
{.HFB:<!}  
*m>XtBw.  
public void run() jIvSjlmI  
{ O,D/& 0  
//获得文件长度 \c1NIuJR  
//分割文件 178u4$# b  
//实例FileSplitterFetch :6T 8\W  
//启动FileSplitterFetch线程 AcoU.tpP  
//等待子线程返回 iHYvH   
try{ RX"~m!26  
if(bFirst) Le?yzf  
{ SWq5=h  
nFileLength = getFileSize(); s.uw,x  
if(nFileLength == -1) dv7IHUFf  
{ l<DpcLX  
System.err.println("File Length is not known!"); ?7eD< |  
} ;)c 4  
else if(nFileLength == -2) q@@C|oqEX  
{ RJ63"F $  
System.err.println("File is not access!"); [(81-j1v  
} gK%^}xU+  
else !et[Rdbu  
{ Fcp8RBq  
for(int i=0;i<nStartPos.length;i++) QBD\2VR  
{ l)P~#G+C  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); [t{ed)J  
} #"PRsMUw  
for(int i=0;i<nEndPos.length-1;i++) =QG0:z)K<v  
{ {=Y3[  
nEndPos = nStartPos[i+1]; 'P`L?/_3  
} wI{ED  
nEndPos[nEndPos.length-1] = nFileLength; 6 @X j  
} O_~vl m<#  
} C)H1<Br7  
+\D?H.P  
"Vw;y+F}  
//启动子线程 WU:r:m+ >  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VNggDKS~K  
for(int i=0;i<nStartPos.length;i++) :enmMB#%  
{ ? CabVj-r  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OZCbMeB{+J  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IPTEOA<M[  
nStartPos,nEndPos,i); q\I2lZ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9FKowF_8  
fileSplitterFetch.start(); PKK18E}{%^  
} %=G*{mK  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 15)y]N={^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lDU@Q(V#}<  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ojwhcb^  
nEndPos = " + nFileLength); iH;IXv,b3  
// fileSplitterFetch[nPos.length-1].start(); =)O%5<Lwx  
Y5&mJp\G  
o)U4RY*  
//等待子线程结束 H%&e[PU  
//int count = 0; 24; BY'   
//是否结束while循环 gQ8FjL6?  
boolean breakWhile = false; x[m&ILr  
I}!Er V  
E4;@P']`  
while(!bStop) :,~]R,tJQ  
{ 7wA.:$  
write_nPos(); 5;4bZ3e,0  
Utility.sleep(500); (imaL,M-D  
breakWhile = true; R{0nk   
4],*y`& g  
6$*\%  
for(int i=0;i<nStartPos.length;i++) ^:Hx.  
{ gd=gc<zYP  
if(!fileSplitterFetch.bDownOver) a}#8n^2  
{ D>>?8a  
breakWhile = false; rd\:.  
break; iQ7S*s+l5O  
} 56JvF*hP  
} G Ch]5\  
if(breakWhile) -&UP[Mq  
break; []#>r k~  
=TcT`](o  
y<0RgG1qp  
//count++; NJqjW  
//if(count>4) !\(j[d#  
// siteStop(); %7vjYvo>  
} Jp#Onl+d6  
@ 5tW*:s  
s/cclFji]  
System.err.println("文件下载结束!"); =IC cN|  
} R/BW$4/E  
catch(Exception e){e.printStackTrace ();} w /l\p3n  
} k&dLg5O  
!STa}wl  
%jc"s\  
//获得文件长度 ROWrkJI>i  
public long getFileSize() E{B8+T:3  
{ Zp'q;h_  
int nFileLength = -1; K>_~zWnc  
try{  |tVWmm^m  
URL url = new URL(siteInfoBean.getSSiteURL()); c1>:|D7w  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eCfy'US;@3  
httpConnection.setRequestProperty("User-Agent","NetFox"); iI 4XM>`a  
^h^\kW'#  
FQp@/H^  
int responseCode=httpConnection.getResponseCode(); 7JL*y\'  
if(responseCode>=400) ~bsL W:.'  
{ C A 8N  
processErrorCode(responseCode); S`?L\R.:  
return -2; //-2 represent access is error 6U!zc]>  
} ^U@-Dp,k+  
Mb +  
q8-*3K  
String sHeader; //O9}-  
Ku3/xcu:My  
o / i W%  
for(int i=1;;i++) jph"94  
{ 5U[bn=n  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7~H.\4HB  
//Utility.log(in.readLine()); YuVg/ '=  
sHeader=httpConnection.getHeaderFieldKey(i); ^.:dT?@R  
if(sHeader!=null) 8-clL\bm  
{ Uk0Fo(HY  
if(sHeader.equals("Content-Length")) \]$TBN dJ4  
{ $ytlj1.  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c'Mi9,q  
break; bayDdR4T  
} E!SxO~  
} g71|t7Q  
else 16Gp nb  
break; 1*vt\,G  
} wB0K e  
} >/eV4ma"  
catch(IOException e){e.printStackTrace ();} EDAVU  
catch(Exception e){e.printStackTrace ();} y%NZ(Y,v  
=T3O;i  
p+7ZGB  
Utility.log(nFileLength); PYPDK*Ie  
UL<*z!y  
oy< q;'  
return nFileLength; zhW.0:9 CR  
} fJ8Q\lb<_  
!c#~g0H+  
A!n)Fpk  
//保存下载信息(文件指针位置) DwBKqhu  
private void write_nPos() gT8%?U:  
{ b$O1I[o  
try{ tIJ?caX5=  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `j1(GQt  
output.writeInt(nStartPos.length); ?V >{3  
for(int i=0;i<nStartPos.length;i++) ;c;5O@R}3  
{ ouO<un  
// output.writeLong(nPos); DuzJQ Sv  
output.writeLong(fileSplitterFetch.nStartPos); Y%"73.x  
output.writeLong(fileSplitterFetch.nEndPos); }+3v5Nz;  
} tJgo% P1  
output.close(); @Q#<-/  
} ,'>,N/JA  
catch(IOException e){e.printStackTrace ();} 3<vw#]yL  
catch(Exception e){e.printStackTrace ();} pjaDtNb  
} JrhDqyk*  
hDAxX= FM  
}2CVA.Qm!  
//读取保存的下载信息(文件指针位置) Th%2pwvER  
private void read_nPos() OEwKT7CX  
{ q\q8xF~[p  
try{ .*acw  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x+B7r& #:  
int nCount = input.readInt(); )xPfz  
nStartPos = new long[nCount]; "1X@t'H38  
nEndPos = new long[nCount]; gI5"\"T{  
for(int i=0;i<nStartPos.length;i++) 8"5^mj  
{ B+Ox#[<75  
nStartPos = input.readLong(); C_q@ixF{  
nEndPos = input.readLong(); B4d\4S_r%  
} NL7CeHs5  
input.close(); DuV@^qSbG.  
} AQR/nWwx  
catch(IOException e){e.printStackTrace ();} "oc&uj  
catch(Exception e){e.printStackTrace ();} IJz=SV  
} }_ [Bp  
[l%6wIP&{  
CUG3C  
private void processErrorCode(int nErrorCode) -w#*~Q{'*  
{ 8n`O{8:fi  
System.err.println("Error Code : " + nErrorCode); Bk)*Z/1<x  
} [<H'JsJl  
|^!  
GR ^d/  
//停止文件下载 AFN"#M  
public void siteStop() wr+r J  
{ "S ~(|G  
bStop = true; 5q Y+^jO]o  
for(int i=0;i<nStartPos.length;i++) !\RBOdw C  
fileSplitterFetch.splitterStop(); u:[vqlU  
0S}ogU[k  
/rQ[Ik$|  
} \ =(r6X  
} zFpM\{`[g  
//负责部分文件的抓取 G:k]tZ*`  
**FileSplitterFetch.java ugT;NB  
*/ M,V~oc5  
package NetFox; 5S&'O4yz^  
D Xjw"^x  
ytkV"^1^  
import java.io.*; ~E J+<[/  
import java.net.*; We51s^(  
qS.TVNZ  
Q#a<T4l  
public class FileSplitterFetch extends Thread { :l/?cV;  
g(`m#&P>G  
LLlt9(^d  
String sURL; //File URL }>T$2"pf  
long nStartPos; //File Snippet Start Position R_ |Sg  
long nEndPos; //File Snippet End Position a"6AZT"8  
int nThreadID; //Thread's ID r iuG,$EX  
boolean bDownOver = false; //Downing is over Utv#E.VI  
boolean bStop = false; //Stop identical :#I7);ol  
FileAccessI fileAccessI = null; //File Access interface \4qw LM?E^  
~,jBm^4  
C[0*>W8o  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException byrK``f  
{ M`jqU g  
this.sURL = sURL; oI2YJ2?Je8  
this.nStartPos = nStart; 5OS|Vp||b  
this.nEndPos = nEnd; xQ{n|)i>  
nThreadID = id; |y T-N3H@  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AXmW7/Sj"  
} ,-[e{=Cz  
H,I k&{@j  
F[HMX4  
public void run() yCt,-mz!z  
{ RD1N@sHDKc  
while(nStartPos < nEndPos && !bStop) #;*0 Pwe`  
{ qC;1ND  
]u\K}n6[q  
GI ~<clhf  
try{ C>bd HB7  
URL url = new URL(sURL); tn@MOOP l  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^qgOgu  
httpConnection.setRequestProperty("User-Agent","NetFox"); p(J,fus  
String sProperty = "bytes="+nStartPos+"-"; (Z{&[h  
httpConnection.setRequestProperty("RANGE",sProperty); *pMu,?uE  
Utility.log(sProperty); <XAW-m9SC  
W{6%Hh p  
djGzJLH  
InputStream input = httpConnection.getInputStream(); +2WvGRC  
//logResponseHead(httpConnection); H/Wo~$  
I<v:x Tor  
-kZOve|5  
byte[] b = new byte[1024]; P*M$^p  
int nRead; T+9#&  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =Y;w O8  
{ E,fG<X{  
nStartPos += fileAccessI.write(b,0,nRead); iR`c/  
//if(nThreadID == 1) e.<y-b?  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p"lTZ7c:Y  
} 4Z"JC9As  
vi :IO  
Ev'Bm Dk  
Utility.log("Thread " + nThreadID + " is over!"); _0uFe7sIZ  
bDownOver = true; CG -^}xE:  
//nPos = fileAccessI.write (b,0,nRead); dDeImSeV  
} M:*^k  
catch(Exception e){e.printStackTrace ();} ;K+'J0  
} a*fUMhIi  
} vxmz3ht,Q  
OB&lq.r  
\4B2%H  
//打印回应的头信息 /'S@iq  
public void logResponseHead(HttpURLConnection con) n,.ZLuBEX  
{ 4Em$L]7   
for(int i=1;;i++) +d=cI  
{ |i-d#x8  
String header=con.getHeaderFieldKey(i); B > sTM  
if(header!=null) ?cF-w!>o8  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |x[zzx# >-  
Utility.log(header+" : "+con.getHeaderField(header)); 5m e|dvk  
else 4jyDM68i  
break; Le*sLuxk<  
} E }*   
} @aX$}  
~SWR|[  
^I4/{,Ev  
public void splitterStop() P<1ZpL  
{ }/{G  
bStop = true; BRu/pyxG  
} mF|7:zSo  
[nBdq"K  
^{vf|zZ _  
} /<\B8^yQ  
tCw.wDq3=  
6N^sUc0s  
/* Gxj3/&]^Y  
**FileAccess.java $G_,$U !  
*//文件访问(定位,写) HalkNR-eEm  
package NetFox; IQz:D J  
import java.io.*; z 5T_  
^3q o%=i  
cc"L> XoK  
public class FileAccessI implements Serializable{ w,'"2^Cwy  
Fa!6*K\  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cnrS.s=  
RandomAccessFile oSavedFile; `k>h2(@9S  
long nPos; FK8G BkQ!  
`(RQh@H  
RH=Tu6i  
public FileAccessI() throws IOException tc_D8Q_  
{ c|s*(WljY  
this("",0); ?4]#gC ks  
} x9c/;Q &m  
: Y{aa1  
$h({x~Oj9  
public FileAccessI(String sName,long nPos) throws IOException N0D)d  
{ <}^W9 >u<  
oSavedFile = new RandomAccessFile(sName,"rw"); G O=&  
this.nPos = nPos; ikSm;.  
oSavedFile.seek(nPos); E903T''s  
} S @EkrC\4n  
{APsi7HYBr  
m _0D^e7#  
public synchronized int write(byte[] b,int nStart,int nLen) %/86}DCfE?  
{ ~m]sJpW<"  
int n = -1; E27N1J+1  
try{ 6+:Tv2  
oSavedFile.write(b,nStart,nLen); RawK9K_1  
n = nLen; 1>doa1  
} x}w"2[fL  
catch(IOException e) '}`|QJ  
{ q=M\#MlL0'  
e.printStackTrace (); q 16jL,i  
} a!;]9}u7  
@Gs*y1  
78s:~|WB<{  
return n; j:yQP# U  
} rt7Ma2tK  
NW.<v /?=,  
J| orvnkK  
} 09f:%!^u  
5 W<\J  
x<0-'EF/S  
/* H?dmNwkPY  
**SiteInfoBean.java PgKA>50a  
*/ 1I?D$I>CV  
package NetFox; }HM8VAH  
lF:gQ]oc  
6z^Kg~a   
public class SiteInfoBean { 4{:W5eT!/  
$II[b-X?S  
YH VJg?H3  
private String sSiteURL; //Site's URL O};U3=^0f  
private String sFilePath; //Saved File's Path T;eA<,H  
private String sFileName; //Saved File's Name Su<Ggv"  
private int nSplitter; //Count of Splited Downloading File +TzF*Np  
|P_\l,f8`  
?UXKy  
public SiteInfoBean() (l28,\Bel  
{//nSplitter的缺省值为5 cT8`l!RD<  
//default value of nSplitter is 5 qsB,yckml  
this("","","",5); ~ caKzq  
} wAr (5nEbx  
?fog 34g  
&CvNNDgrJ  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U&fOsx?"  
{ U/ncD F%C  
sSiteURL= sURL; cxTP4\T\E  
sFilePath = sPath; rz]0i@ehv'  
sFileName = sName; &^ sgR$m  
this.nSplitter = nSpiltter; >K{/Jx&  
 +X i#y}%  
apxZ}  
} zMfr`&%e  
`laaT5G\y  
<a-I-~  
public String getSSiteURL() Ni5~Buf  
{ la ~T)U7  
return sSiteURL; U!:Q|':=h  
} D6iHkDTg  
ti:qOSIDTA  
7$(>Z^ Em  
public void setSSiteURL(String value) 8K! l X  
{ d}K"dr:W5  
sSiteURL = value; SRl:+!@.  
} |-N\?N9"  
&zsaVm8  
K2T&U$ ,  
public String getSFilePath() vUGEzCM  
{ N[ %^0T$  
return sFilePath; (F$V m  
} l`L}*Q- 5  
G9s: Wp  
+OFq=M  
public void setSFilePath(String value) `A@{})+  
{ iH& Izv  
sFilePath = value; =T)4Oziks  
} }/ 6Q3B  
]HP aM  
@O}%sjC1  
public String getSFileName() *0)vsBi  
{ 6(4FC?Y7  
return sFileName; +'abAST t  
} :\x)`lu  
N"2Ire  
JcEPwF.  
public void setSFileName(String value) VnUW UIVJ  
{ OWsK>egD  
sFileName = value; ?5e:w?&g@  
} 2f1WT g)  
YEoQIR  
xzg81sV7  
public int getNSplitter() 'c 0]8Y 4  
{ 1 dT1DcZ  
return nSplitter; n?*Fr sZ  
} "nX L7N0  
l~,5)*T  
$LLkYOwI  
public void setNSplitter(int nCount) A-\OB Nh  
{ nwh7DU i  
nSplitter = nCount; &MnS( 82L  
} >3V{I'^^-  
} $:V'+s4o  
^)Xl7d|m+  
~:r:?PwWG  
/* * 8n0  
**Utility.java ^9zL[R  
*/ 6q ._8%  
package NetFox; ${^WM}N  
Hc1S:RW  
:T(3!}4  
public class Utility { H8+7rM  
/t`s.!k  
dieGLA<5_X  
public Utility() won;tO]\;@  
{ m @) ~.E  
s/+@o:  
)(`I1"1   
} X TpYf  
F@Qzh  
//线程睡眠 RnV )*  
public static void sleep(int nSecond) E7-il;`cKn  
{ g$<Sh.4A  
try{ H(U`S  
Thread.sleep(nSecond); 4(>|f_$  
} K^j7T[pR  
catch(Exception e) \EF^Ag  
{ 4$ LVl  
e.printStackTrace (); UN'[sHjOnD  
} 6('2.^8  
} ?zW4|0  
Vo^ i7  
//日志 Pu dIb|V2  
public static void log(String sMsg) ,h,DB=!K<  
{ .$5QM&  
System.err.println(sMsg); VWqmqR%  
} .}Va~[0j  
9~i=Af@  
&GF@9BXI3  
public static void log(int sMsg) zi l^^wT0J  
{ hw/ :  
System.err.println(sMsg); ]cvP !  
}  }t}y  
}  nen(  
EYNi`  
$'FPsoH  
/* Y=+pz^/"  
**TestMethod.java UfcQFT{()  
*/ F}p)Q$0  
package NetFox; ? S^ U-.`  
rEEoR'c6  
(D5 dN\  
public class TestMethod { 8."B  
2fIHFo\8  
k I  
public TestMethod() Q-<N)K$F(4  
{ ///xx/weblogic60b2_win.exe ,TL8`  
try{ S- {=4b'  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zvjp]yTx"  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *Ii_dpJ  
SiteFileFetch fileFetch = new SiteFileFetch(bean); wWjZXsOd  
fileFetch.start(); #[$^M:X.  
} 5Fa.X|R~  
catch(Exception e){e.printStackTrace ();} Fq\vFt|m<  
S"+X+Oxp7?  
jroR 2*  
} 0;9X`z J  
5=Cea  
r]JV !'R  
public static void main(String[] args) jpijnz{M  
{ @@->A9'L  
new TestMethod(); fS9TDy  
} `5da  
} 4mYJi#e6x  
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