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http断点续传简单实现(java)

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/* Mq0MtC6-  
**SiteFileFetch.java x1 |/  
*/ 9y!0WZE{e  
package NetFox; ]+I9{%zB%8  
import java.io.*; l[E^nh>  
import java.net.*; h .Qk{v  
7!J-/#!  
}; '@'   
public class SiteFileFetch extends Thread { B:"D)/\  
q1rj!7  
T1Py6Q,-  
SiteInfoBean siteInfoBean = null; //文件信息Bean V(`]hH0;T  
long[] nStartPos; //开始位置 _# {*I(l  
long[] nEndPos; //结束位置 ~R|9|k  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 IHEbT   
long nFileLength; //文件长度 XUP{]w`.Z  
boolean bFirst = true; //是否第一次取文件 HT.,BF  
boolean bStop = false; //停止标志 =;Q/bD->  
File tmpFile; //文件下载的临时信息 $z$^ yjL  
DataOutputStream output; //输出到文件的输出流 _mm(W=KiL  
yY8zTWji_  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 'Ix@<$~i3F  
public SiteFileFetch(SiteInfoBean bean) throws IOException #zsaQg, B  
{ nD5wN~[J  
siteInfoBean = bean; _[[0rn$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); %IO*(5f  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 7hk<{gnr  
if(tmpFile.exists ()) ^Laqq%PI  
{ e|k]te  
bFirst = false; aU6l>G`w  
read_nPos(); %Y~"Stmx  
} 7T/BzXr,B  
else Z^'~iU-?  
{ T";evM66  
nStartPos = new long[bean.getNSplitter()]; ,>B11Z}PH  
nEndPos = new long[bean.getNSplitter()]; Z )c\B  
} GFFwk4n1  
7^i7U-A<A  
'HW l_M  
$NR[U+  
} :)lS9<Y}  
]T)N{"&N/  
=2$ ( tXL  
public void run() C_J@:HlJ  
{ |Ahf 01  
//获得文件长度 =d Q[I6  
//分割文件 uGZGI;9f4  
//实例FileSplitterFetch xgxfPcI  
//启动FileSplitterFetch线程  T7nI/y  
//等待子线程返回 _*H Hdd5I  
try{ CR$wzjP j  
if(bFirst) \ ITd\)F%N  
{ ec ;  
nFileLength = getFileSize(); i bzY&f  
if(nFileLength == -1) /phMrL=  
{ !; >s.]  
System.err.println("File Length is not known!"); =DdPwr 0Op  
} Rrh6-]A  
else if(nFileLength == -2) %np(z&@wi  
{ "s|P,*Xf  
System.err.println("File is not access!"); 3VLwY!2:  
} ?kR1T0lKkE  
else NFTv4$5d  
{ WVR/0l&bU  
for(int i=0;i<nStartPos.length;i++) a{xJ#_/6  
{ [7}3k?42X  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); {dxFd-K3  
} VzXVy)d  
for(int i=0;i<nEndPos.length-1;i++) t"B3?<?]  
{ Ue \A ,  
nEndPos = nStartPos[i+1]; YC1Bgz  
} \Vme\Ke*v)  
nEndPos[nEndPos.length-1] = nFileLength; |tAkv  
} )p>Cf_[.  
} v]M:HzP  
9`Qa/Y!  
z I2DQ] 9  
//启动子线程 8gavcsVE[  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0U7Gl9~  
for(int i=0;i<nStartPos.length;i++) .F,l>wUNe  
{ zg ,=A?  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &.E/%pQ`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AO8 #l YP?  
nStartPos,nEndPos,i); <}lah%4F  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [2,D]e  
fileSplitterFetch.start(); I/w;4!+)  
} H5 z1_O_+  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r[(;J0=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;h1hz^Wq  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Tz)Ku  
nEndPos = " + nFileLength); ,marNG  
// fileSplitterFetch[nPos.length-1].start(); :,l16{^  
ZV--d'YiEm  
Jk%5Fw0  
//等待子线程结束 |fKT@2(  
//int count = 0; ^ ##j {h7  
//是否结束while循环 a]*{!V{$i  
boolean breakWhile = false; 9}QIqH\p  
z6)N![ X  
UJ,vE}=_{  
while(!bStop) Lk|`\I T  
{ f+9WGNpw  
write_nPos(); E"'u2jEG^  
Utility.sleep(500); pyV`O[  
breakWhile = true; #M~yt`R~  
+\ftSm>  
s=:)!M.i  
for(int i=0;i<nStartPos.length;i++) -r,v3n  
{ [s$x"Ex  
if(!fileSplitterFetch.bDownOver) ?;oJ=.T  
{ `xx.,;S  
breakWhile = false; B>1,I'/$.  
break; (W#CDw<ja  
} 4 xqzdR_  
} 0 7Yak<+~  
if(breakWhile) w)|9iL8  
break; pfZ[YC-  
FdE?uw  
'4M{Xn}@  
//count++; m!KEK\5M?  
//if(count>4) NxF:s,a6  
// siteStop(); g$NUu  
} x:0swZ5Z  
AM=> P 7  
d;<'28A  
System.err.println("文件下载结束!"); \FfqIc9;  
} +@]k[9  
catch(Exception e){e.printStackTrace ();} 8o+:|V~X  
} hdWVvN  
8?8V;   
0S :&wb  
//获得文件长度 ,y'6vW`%g9  
public long getFileSize() @k{q[6c2 n  
{ 9n is8  
int nFileLength = -1; $VQ;y|K+[  
try{ DTH}=r-  
URL url = new URL(siteInfoBean.getSSiteURL()); p>eYi \'  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R`]@.i4tt  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8x- 19#  
/fUdb=!Z  
cWo>DuW&  
int responseCode=httpConnection.getResponseCode(); Rd HCbk  
if(responseCode>=400) ~ S<aIk0l  
{ hiibPc?I  
processErrorCode(responseCode);  omg#[  
return -2; //-2 represent access is error Yr"Of*VNH  
} QOK,-  
c $r"q :\  
E[#VWM I  
String sHeader; SrH::-{  
h!uyTgq  
Y=|p}>.}  
for(int i=1;;i++) :l"B NT[/  
{ U"/T`f'H z  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "Y^j=?1k  
//Utility.log(in.readLine()); Zoxblk  
sHeader=httpConnection.getHeaderFieldKey(i); eCR^$z=c  
if(sHeader!=null) r+m.! +  
{ =8#.=J[/  
if(sHeader.equals("Content-Length")) ,mx\ -lWFy  
{ |pS]zD  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aV7VbC  
break; rR":}LA^d  
} JwxKWVpWv  
} )NhC+=N  
else N$Ad9W?T  
break; 5.ab/uk;M  
} @:RoYvk$  
} E9mu:T  
catch(IOException e){e.printStackTrace ();} h2x9LPLBxT  
catch(Exception e){e.printStackTrace ();} . s>@@m-  
,9d]-CuP;  
*Sdx:G~gp  
Utility.log(nFileLength); cH*")oD  
@. $- ^-  
V*PL_|Q5  
return nFileLength; n%29WF6Zf  
} )V~=B]  
4v/MZ:%C`  
l!XCYg@67  
//保存下载信息(文件指针位置) @Ol(:{<  
private void write_nPos() t O.5  
{  !AJkd.  
try{ -5  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~5N oR  
output.writeInt(nStartPos.length); _f";zd  
for(int i=0;i<nStartPos.length;i++) B<L7`xL  
{ 9tv,,I;iU  
// output.writeLong(nPos); bwhH2^ !  
output.writeLong(fileSplitterFetch.nStartPos); q++\< \2  
output.writeLong(fileSplitterFetch.nEndPos); n_; s2,2r  
} $.C-_L  
output.close(); m W>Iib|  
} >v, si].  
catch(IOException e){e.printStackTrace ();} 6\I^]\YO  
catch(Exception e){e.printStackTrace ();} $adZ|Q\  
} tqpO3  
@Q,Q"c2  
\~A qA!)6  
//读取保存的下载信息(文件指针位置) ^CLQs;zXE  
private void read_nPos() !@ ]IJ"\  
{ *GoTN  
try{ r!f UMDS  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2#:p:R8I>  
int nCount = input.readInt(); M5w/TN  
nStartPos = new long[nCount]; r@C~_LgL)  
nEndPos = new long[nCount]; Dq~;h \='  
for(int i=0;i<nStartPos.length;i++) 1xEOYM)  
{ =q]!"yU[d  
nStartPos = input.readLong(); I ?Dp *u*  
nEndPos = input.readLong(); ;6``t+]q   
} Z6${nUX  
input.close(); Ur]$@N  
} #0T/^ #  
catch(IOException e){e.printStackTrace ();} hT1JEu  
catch(Exception e){e.printStackTrace ();} FfM^2`xP  
} MZ$uWm`/  
TMMJ5\t2  
5\z<xpJ  
private void processErrorCode(int nErrorCode) CnL=s6XD'  
{ H}kSXKO8!8  
System.err.println("Error Code : " + nErrorCode); MuOKauYa  
} nyi!D   
tXtNK2-1  
f%.Ngf9  
//停止文件下载 [HY r|T  
public void siteStop() LWJ ?p-X  
{ '42$O  
bStop = true; f0SrPc v  
for(int i=0;i<nStartPos.length;i++) bD,X.  
fileSplitterFetch.splitterStop(); pml33^*<U  
g=4^u*  
Gu~*ZKyJ  
} aA#79LS  
} ~5&4s  
//负责部分文件的抓取 1b1Ab zN  
**FileSplitterFetch.java tjFX(;^[  
*/ V>T?'GbS  
package NetFox; ~ C%I'z'  
nI]EfHU  
:1UMA@HP  
import java.io.*; 8lpAe0p(Z  
import java.net.*; O_1[KiZ  
X8ap   
z5$Q"Y.D  
public class FileSplitterFetch extends Thread { A`Dx]y  
:CE4< {V  
KL=<s#  
String sURL; //File URL \wA:58 -j  
long nStartPos; //File Snippet Start Position 0pMN@Cz6  
long nEndPos; //File Snippet End Position ` 'Qb?F6  
int nThreadID; //Thread's ID K2 M=)B  
boolean bDownOver = false; //Downing is over Oh$:qu7o0&  
boolean bStop = false; //Stop identical D`WRy}o  
FileAccessI fileAccessI = null; //File Access interface P!|Z%H  
PX|@D_%Y=  
&$/ #"lW,V  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d)vP9vXy  
{ nte?a e  
this.sURL = sURL; K#Ck,Y"  
this.nStartPos = nStart; HCN/|z1Xq  
this.nEndPos = nEnd; *z VN6wG{  
nThreadID = id; qMJJBl  
fileAccessI = new FileAccessI(sName,nStartPos);//定位  viAAb  
} yV8J-YdsG  
L_!ShE  
oVy{~D=  
public void run() O<cP1TF  
{ ;`#R9\C=h  
while(nStartPos < nEndPos && !bStop) :Mu*E5  
{ swF{}S"  
bOj)Wu  
VdK%m`;2  
try{ NV4g5)D&L  
URL url = new URL(sURL); -Ty~lZ)TDT  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !} TsFa  
httpConnection.setRequestProperty("User-Agent","NetFox"); {3`385  
String sProperty = "bytes="+nStartPos+"-"; 4=tR_s  
httpConnection.setRequestProperty("RANGE",sProperty); +>q#eUS)  
Utility.log(sProperty); :_R:>n9 p  
 JaY"Wfc  
12n:)yQy  
InputStream input = httpConnection.getInputStream(); &Pr\n&9A  
//logResponseHead(httpConnection); uAPVR  
:82h GU  
#; ?3k uq(  
byte[] b = new byte[1024]; xrkl)7;  
int nRead; E7A!,A&>  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }'x;J   
{ GkJcd;  
nStartPos += fileAccessI.write(b,0,nRead); Zl5'%b$&  
//if(nThreadID == 1) @zg}x0]  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hN'])[+V  
} Tsg9,/vXM  
XH!#_jy  
KR aL+A  
Utility.log("Thread " + nThreadID + " is over!"); .ImaM  
bDownOver = true; cFL~< [>_  
//nPos = fileAccessI.write (b,0,nRead); ZkbE&7Z  
} !y _{mE?V(  
catch(Exception e){e.printStackTrace ();} |Ghk8 WA  
} Q6Gw!!Z5EA  
} /IpCo  
;>?h/tS6  
Ki;SONSV~|  
//打印回应的头信息 7s(tAbPdB  
public void logResponseHead(HttpURLConnection con) 92DM1~ *  
{ ss)x fG  
for(int i=1;;i++) dDPQDIx  
{ _B^zm-}8|B  
String header=con.getHeaderFieldKey(i); @oAz  
if(header!=null) T^}UE<  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~gfR1SE  
Utility.log(header+" : "+con.getHeaderField(header)); >c,s}HJ  
else 'Z`7/I4&  
break; !K>iSF<  
} KMRPleF  
} =5+*TL`  
7<yc:}9nx  
LCHMh6  
public void splitterStop() (wDE!H7  
{ GI%&.Vd  
bStop = true; F_ F"3'[  
} cszvt2BIg  
sAkr-x?+M  
J$3g3%t  
} @ma(py  
5WQl?yMP  
kTvM,<  
/* D4=*yP  
**FileAccess.java 79h~w{IT@  
*//文件访问(定位,写) fW-C`x  
package NetFox; ShB]U5b:k  
import java.io.*; .;?!I_`  
eTuqK23  
I^ ?tF'E  
public class FileAccessI implements Serializable{ kU<t~+  
l[}4 X/  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c2npma]DZ  
RandomAccessFile oSavedFile; tq3_az ~1  
long nPos; y }odTeq  
C ^Y\?2h1  
8-2 `S*  
public FileAccessI() throws IOException 4V,.Oi  
{  $GJT  
this("",0); x|6]+?l@6  
} wX,V:QE  
<g[z jV9p  
%nZl`<M  
public FileAccessI(String sName,long nPos) throws IOException {a7~P0$  
{ x e`^)2z  
oSavedFile = new RandomAccessFile(sName,"rw"); vi,hWz8WB  
this.nPos = nPos; 7j]v_2S`  
oSavedFile.seek(nPos); ~e{ @5.g  
} 1 R5 pf  
ZwmucY%3  
-#|D>  
public synchronized int write(byte[] b,int nStart,int nLen) NQ9v[gv  
{ k ka5=u  
int n = -1; ;5Sdx5`_  
try{ @]=40Yj~w  
oSavedFile.write(b,nStart,nLen); WgtLKRZ\  
n = nLen; $]2)r[eA)  
} jJ ,_-ui  
catch(IOException e) 1+x" 5<(W  
{ QU).q65p  
e.printStackTrace (); jj5S+ >4  
} EApKN@<"  
b^1QyX^?:  
eVXXn)>  
return n; F-yY(b]$  
} D|;O9iks#  
*%j$i_  
-=ZL(r 1  
} .G0 N+)  
Luq4q95]  
7;'33Bm*  
/* y~SVD@  
**SiteInfoBean.java J +6zV m  
*/ .JhQxXj  
package NetFox; _P;D.>?  
[,zq  
uw)7N(os\`  
public class SiteInfoBean { ym%UuC3^w  
&gXh:.  
4QL>LK  
private String sSiteURL; //Site's URL '%NglC[J  
private String sFilePath; //Saved File's Path AU{"G  
private String sFileName; //Saved File's Name fr@F7s5}  
private int nSplitter; //Count of Splited Downloading File 7},A. q  
=CX1jrLZ  
^kez]>   
public SiteInfoBean() rd%%NnT"  
{//nSplitter的缺省值为5 )#=J<OpG  
//default value of nSplitter is 5 ]\$/:f-2  
this("","","",5); +# W94s~0V  
} Gz[yD ~6a  
r~4uIUE{  
7u):J  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rO1!h%&o"  
{ 3*b5V<}'|  
sSiteURL= sURL; V$^jlWdR  
sFilePath = sPath; 4=zs&   
sFileName = sName; )9QtnM  
this.nSplitter = nSpiltter; qNp1<QO0  
#&Sr;hAJ  
K2   
} {$*N1$(%  
(i1JRn-f  
e[S`Dm"i)'  
public String getSSiteURL() 8.E"[QktZ  
{ x%{]'z  
return sSiteURL; $pGT1oF[E  
} @f!X%)\;x  
<n"BPXF~  
U|(+-R8Z  
public void setSSiteURL(String value) bz>X~   
{ em$pU*`P  
sSiteURL = value; O] _4pP  
} W U(_N*a  
x&}]8S)  
1H)mJVIKkB  
public String getSFilePath() nB[-KS  
{ JzHG5nmB  
return sFilePath; NW3 c_]`=  
} 4zug9kFK  
my=f}%k=  
RaZ>.5 D  
public void setSFilePath(String value) 92+8zX  
{ c\bL_  
sFilePath = value; Ucj?$=  
} ZykMri3bi  
cs9^&N:w[  
v9$!v^U"D  
public String getSFileName() rr<E#w  
{ >ZA=9v  
return sFileName; bp1AN9~  
} .8hI ad  
+/:tap|V  
C*9X;+S0J  
public void setSFileName(String value) 1I +9?fa  
{ :FyF:=  
sFileName = value; 9 _d2u#  
} >yIJ8IDF  
xo:kT)  
hy;VvAH 5  
public int getNSplitter() IRdt:B|@  
{ O 4 !$  
return nSplitter; E+td~&x  
} hbjAxioA  
*[Hrbln  
#;!&8iH  
public void setNSplitter(int nCount) 'sNZFB#  
{ S63 Zk0(25  
nSplitter = nCount; )Q)qz$h@  
} 6CJMQi,kn  
} 8;PkuJR_]  
yNTd_XPL  
DE?v'7cmA  
/* &W `xZyb3  
**Utility.java R>Ra~ b  
*/ 9KSi-2?H  
package NetFox; _IH" SVub  
rg/{5f  
%H{p&ms  
public class Utility { | HazM9=  
xO$P C,  
?KT{H( rU  
public Utility() R1jl<=  
{ pYO =pL^Q  
\& JZ >h  
qnm_#!&uHT  
} (8nv&|  
]@q%dsz  
//线程睡眠 xNz(LZ.c  
public static void sleep(int nSecond) #-hO\ QdC  
{ v=`yfCX-qX  
try{ x2"iZzQlD  
Thread.sleep(nSecond); LQ0/oYmNc  
} yNu_>!Cp5  
catch(Exception e) ?^|`A}q#  
{ h8rW"8Th  
e.printStackTrace (); Bx\&7|,x  
} V0ze7tSG[f  
} 8^mE<  
$KHm5*;nd  
//日志 kmB!NxF>)F  
public static void log(String sMsg) !^J;S%MB:K  
{ !iXRt")  
System.err.println(sMsg); \1EuHQ?  
} b*|~F  
7Z-j'pq  
Z%T Ajm  
public static void log(int sMsg) Sn CwoxK  
{ g40Hj Y  
System.err.println(sMsg); OATdmHW  
} jm0p%%z  
} _=v#"l  
+z >)'#  
OG\i?N  
/* )0{`}7X  
**TestMethod.java QV4|f[Ki%  
*/ m 0HK1'  
package NetFox; .hTqZvDa  
Q=~"xB8  
PK*Wu<<  
public class TestMethod { \0$+*ejz  
Q PH=`s  
A=|XlP$6  
public TestMethod() _0H oJ  
{ ///xx/weblogic60b2_win.exe UBvp3 2p  
try{ i,Ct AbMx  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uo F.f$%"  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^$c#L1 C  
SiteFileFetch fileFetch = new SiteFileFetch(bean); |OQ]F  
fileFetch.start(); 8f@}-  
} .?>Cav9:  
catch(Exception e){e.printStackTrace ();} rb?7i&-  
<O#&D|EMd|  
^BsT>VSH6  
} *dBy<dIy  
3bEcKA_z(  
d\z6Ob"t  
public static void main(String[] args) =j7Du[?Vu  
{ dab]>% M  
new TestMethod(); -YoL.`s1   
} w,{h9f  
} 6j E.X  
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