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http断点续传简单实现(java)

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/* 7cQHRM+1  
**SiteFileFetch.java VA*79I#_q  
*/ N NXwT0t  
package NetFox; Jh hT7\h(  
import java.io.*; jTxChR  
import java.net.*; b&_u O  
Hr64M0V3B  
HhT8YH  
public class SiteFileFetch extends Thread { ](( >i%%~  
&bRxy`ZH  
% /wP2O<  
SiteInfoBean siteInfoBean = null; //文件信息Bean 0zk T8'v  
long[] nStartPos; //开始位置 c&iK+qvh{  
long[] nEndPos; //结束位置 4FP~+  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 |'>E};D  
long nFileLength; //文件长度 _S7M5{U_  
boolean bFirst = true; //是否第一次取文件 ` TVcI\W  
boolean bStop = false; //停止标志 j,V$vKP  
File tmpFile; //文件下载的临时信息 lyc{Z%!3  
DataOutputStream output; //输出到文件的输出流 E6d8z=X(  
^#6%*(D  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) =Z$=-\<x0.  
public SiteFileFetch(SiteInfoBean bean) throws IOException kA9 X!)2w  
{ \Q BpgMi(  
siteInfoBean = bean; g{f>j d  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); [OToz~=)  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); HZ`G)1&)  
if(tmpFile.exists ()) 5 <>agK]  
{ gpTF^.(  
bFirst = false; %2FCpre;  
read_nPos(); I}CA-8  
} 0jx~_zq-j  
else ():?FJ M  
{ 5In8VE !P  
nStartPos = new long[bean.getNSplitter()]; GzE3B';g  
nEndPos = new long[bean.getNSplitter()]; vd X~E97  
} D_;n4<|.  
]> "/<"  
Gxt<kz  
frO/ nx|9  
} q.K$b  
ClVpb ew  
,h(+\^ ?,  
public void run() ^# g;"K0  
{ z4%F2Czai&  
//获得文件长度 W1,L>Az^Ts  
//分割文件 |$-d, ] V  
//实例FileSplitterFetch -JW6@L@  
//启动FileSplitterFetch线程 .j$bCKXGx  
//等待子线程返回 3'NL1du  
try{ 9;WOqBD  
if(bFirst) Xcpm?aTo  
{ 6}FDLBA  
nFileLength = getFileSize(); x@R A1&c  
if(nFileLength == -1) CjukD%>sde  
{ oL/^[TXjH  
System.err.println("File Length is not known!"); XjM)/-w  
} X;a{JjN  
else if(nFileLength == -2) A2FU}Ym0=  
{ uEO2,1+  
System.err.println("File is not access!"); 2n r UE  
} H_r'q9@<>  
else ZN]c>w[ )I  
{ >Ti2E+}[M  
for(int i=0;i<nStartPos.length;i++) 0Y`tj  
{ w*R-E4S?2  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Y8xnvK*  
} r{3 `zqo  
for(int i=0;i<nEndPos.length-1;i++) Xv(9 Yh S  
{ X!+ a;wr  
nEndPos = nStartPos[i+1]; ,$(v#Tz  
} v/6,eIz  
nEndPos[nEndPos.length-1] = nFileLength; CoN/L`.SN  
} z7}zf@Y-qv  
} >Ezwl5b  
Rm 1`D  
CO+jB  
//启动子线程 .7^-*HT}  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1X}Tp\e  
for(int i=0;i<nStartPos.length;i++) a9_KQ=&CI  
{ 8 =Lv7G%  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 40sLZa)e  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P+|8MT0  
nStartPos,nEndPos,i); J7] 60H#P  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #.t{g8W\C  
fileSplitterFetch.start(); !>);}J!e]  
} *U^hwL  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *M<=K.*\G  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]<?)(xz  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1KR|i"  
nEndPos = " + nFileLength); &>b1ES.>  
// fileSplitterFetch[nPos.length-1].start(); ;l4 \^E1  
{!?RG\EYN  
pNWp3+a'  
//等待子线程结束 >^ar$T;Ys  
//int count = 0; R}26"+~  
//是否结束while循环 qiryC7.E  
boolean breakWhile = false; 0-~x[\>>  
[$Bb'],k  
ll09j Ef  
while(!bStop) (`Mz.VN  
{ y5D?Bg|M  
write_nPos(); +E[)@;T  
Utility.sleep(500); w[G_w:$a  
breakWhile = true; Z69 IHA[  
bbkI}d%(Ng  
>U/g*[>  
for(int i=0;i<nStartPos.length;i++) fb;"J+  
{ |;-r};  
if(!fileSplitterFetch.bDownOver) L2$L.@  
{ sYP@>tHC  
breakWhile = false; MW>28  
break; j]D =\  
} !Qzp!k9d  
} /j@r~mt/pA  
if(breakWhile) O; sQPG,v  
break; [k}\{i>  
}]?G"f t K  
gQDK?aQX  
//count++; i?=.; 0[|  
//if(count>4) o+Z9h1z%,  
// siteStop(); iRtDZoiD'  
} S:\hcW6  
Y\|J1I,Z4  
l!` 0I] }  
System.err.println("文件下载结束!"); * XGBym  
} e !Okc*,  
catch(Exception e){e.printStackTrace ();} W-QPO  
} X5<.%@Z  
93DBZqN  
B '/ >Ax&  
//获得文件长度 0.0!5D[  
public long getFileSize() 1hS~!r'qqv  
{ x@}Fn:c!5  
int nFileLength = -1; ,O!aRvzap  
try{ Z$XpoDbOy  
URL url = new URL(siteInfoBean.getSSiteURL()); LS$82UB&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L:Eb(z/D  
httpConnection.setRequestProperty("User-Agent","NetFox"); PtOnj)Q  
KHN ,SB  
}O  
int responseCode=httpConnection.getResponseCode(); l$9,  
if(responseCode>=400) 74(J7  
{ 1iDo$]TEK  
processErrorCode(responseCode); =7,U qMl_  
return -2; //-2 represent access is error "6QMa,)D  
} d]`,}vi#E9  
J,Ap9HJt  
;P~S/j[ 8  
String sHeader; Q>yt O'v1  
.Tv(1HAc2l  
$ '*BS  
for(int i=1;;i++) r ngw6?`n-  
{ V5 r7eC  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L{pg?#\yC  
//Utility.log(in.readLine()); oy: MM  
sHeader=httpConnection.getHeaderFieldKey(i); 2&URIQg*J  
if(sHeader!=null) #{,IY03  
{ 18`%WUPnT  
if(sHeader.equals("Content-Length")) E%B Gf}h  
{ SqB|(~S  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D0i30p`  
break; +Bfi/>  
} N@)~j+Pz  
} 2N 4>  
else :5J6rj;_  
break; 3kY4V*9@-  
} Bdepvc}[#  
} ZRfa!9vl  
catch(IOException e){e.printStackTrace ();} s3 $Q_8H  
catch(Exception e){e.printStackTrace ();} 3)SZVME1Z  
Q$j48,e  
;$< ek(i7  
Utility.log(nFileLength); }wXD%X@)l  
t7FQ.E,T  
&J:)*EjVl5  
return nFileLength; nDy=ZsK  
} koZp~W-  
p04+"  
"cM5=;  
//保存下载信息(文件指针位置) G - WJlu  
private void write_nPos() I_7EfAqg(  
{ It-*CD9  
try{ He3zV\X[Z  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2z3A"HrlA  
output.writeInt(nStartPos.length); P.DWC'IBN  
for(int i=0;i<nStartPos.length;i++) ?F{xDfqw  
{ 'O9=*L) X  
// output.writeLong(nPos); @x +#ZD(  
output.writeLong(fileSplitterFetch.nStartPos); / u6$M/Cf>  
output.writeLong(fileSplitterFetch.nEndPos); <Q)}  
} B$EP'5@b  
output.close(); \'*`te:{  
} ,c l<74d  
catch(IOException e){e.printStackTrace ();} [{$0E=&0  
catch(Exception e){e.printStackTrace ();} i]pG}SJ  
} "~ stZ.  
@un }&URp  
2"mj=}y6  
//读取保存的下载信息(文件指针位置) 8 GN{*Hg  
private void read_nPos() F9r*ZyNlx  
{ o#/iR]3  
try{ 1H7Q[ 2E  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )W|jt/  
int nCount = input.readInt(); p>3'77 V  
nStartPos = new long[nCount]; n4y6Ua9m{  
nEndPos = new long[nCount]; %;$Y|RbmqE  
for(int i=0;i<nStartPos.length;i++) _B FX5ifK  
{ 38i,\@p`9$  
nStartPos = input.readLong(); 3 ?~+5DU  
nEndPos = input.readLong(); 8-YrmP2k  
} WEAXqDjM  
input.close(); +Ob#3PRy  
} );H[lKy  
catch(IOException e){e.printStackTrace ();} 4+,Z'J%\[7  
catch(Exception e){e.printStackTrace ();} T]-~?;Jh8  
} [)vwg`]   
*PU,Rc()6  
w[YbL2p  
private void processErrorCode(int nErrorCode) ygt)7f5  
{ >]8.xkQq  
System.err.println("Error Code : " + nErrorCode); 4LJ}>e  
} X{9o8 *V  
/j@ `aG(a  
!5t 3Y  
//停止文件下载 4{t$M}?N  
public void siteStop() 2tm-:CPG  
{ ~la04wR28  
bStop = true; >Fk `h=Wd  
for(int i=0;i<nStartPos.length;i++) T?{9Z  
fileSplitterFetch.splitterStop(); v=-3 ,C  
Qp&yS U8  
h xJgxM  
} :=v{inN  
} #q.G_-H4J@  
//负责部分文件的抓取 6*33k'=;F  
**FileSplitterFetch.java _O9H. _E  
*/ Y_hRL&u3W  
package NetFox; ld:alEo  
~ O=|v/]  
)^f Q@C8  
import java.io.*; R9G)X]  
import java.net.*; 9yw/-nA  
pu*u[n  
WVK-dBU  
public class FileSplitterFetch extends Thread { l{m~d!w`a  
MPy][^s!  
E9 q;>)}  
String sURL; //File URL D#}Yx]Q1  
long nStartPos; //File Snippet Start Position B/kn&^z$|~  
long nEndPos; //File Snippet End Position K(fLqXE%  
int nThreadID; //Thread's ID g_c)Ts(  
boolean bDownOver = false; //Downing is over bv>lm56  
boolean bStop = false; //Stop identical jZ,[{Z(N   
FileAccessI fileAccessI = null; //File Access interface a;(zH*/XK  
JMl hBh  
\[I .  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $= xQX  
{ ~<OjXuYu  
this.sURL = sURL; >1I2R/'  
this.nStartPos = nStart; (ul-J4E\O  
this.nEndPos = nEnd; %kFELtx  
nThreadID = id; 1y-lZ}s_  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 CVG>[~}(9'  
} EFt`<qwj  
<`UG#6z8  
C_ZD<UPA\  
public void run() H-KwkH`L4  
{ _D,f 4.R  
while(nStartPos < nEndPos && !bStop) ,T*_mDVY  
{ VD3MJ8!w  
%7d@+ .  
*u;">H*BW  
try{ 1za'u_  
URL url = new URL(sURL); ,xD*^>!  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x$ J.SbW  
httpConnection.setRequestProperty("User-Agent","NetFox"); jNG?2/P6&  
String sProperty = "bytes="+nStartPos+"-"; 1(7.V-(G  
httpConnection.setRequestProperty("RANGE",sProperty); 'qF3,Rw  
Utility.log(sProperty); TKu68/\)  
BRXb<M^;_  
KSB_%OI1  
InputStream input = httpConnection.getInputStream(); Yj7= T%5  
//logResponseHead(httpConnection); 6aZt4Lw2\  
yki51rOI*  
3_*Xk. .d  
byte[] b = new byte[1024]; Etc?;Z[F#  
int nRead; %i -X@.P  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^lc}FN  
{ :`u&TXsu  
nStartPos += fileAccessI.write(b,0,nRead); K[>@'P}y  
//if(nThreadID == 1) UtBlP+bE?y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i,Wm{+H-O  
} /\a]S:V-j  
OV("mNh  
p@7i=hyt`p  
Utility.log("Thread " + nThreadID + " is over!"); H;*a:tbxO+  
bDownOver = true; x1V2|~;p|  
//nPos = fileAccessI.write (b,0,nRead); oD#< ?h)(  
} ^c0$pqZ}r  
catch(Exception e){e.printStackTrace ();} P`3s\8[Q  
} 7l#2,d4  
} "^ 6lvZP(  
[b i3%yWh  
?%xhe  
//打印回应的头信息 m,gy9$  
public void logResponseHead(HttpURLConnection con) _{c|o{2sj  
{ yw* mA1v  
for(int i=1;;i++) cR=94i=t  
{ k BiBXRt  
String header=con.getHeaderFieldKey(i); h/ X5w4  
if(header!=null) ( ztim  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >)n4s Mq  
Utility.log(header+" : "+con.getHeaderField(header)); U%^eIXV|  
else ~6-"i0k  
break; % L >#  
} 1] %W\RHxo  
} b$goF }b'g  
;naq-%'Sg  
W%>i$:Qq  
public void splitterStop() KZrMf77=  
{ AvrL9D  
bStop = true; KM/U?`6>:  
} p2Dh3)&  
:>P4L,Da]  
H}sS4[z  
} a/QtJwIV  
*^@#X-NG  
crJ7pe9  
/* ~[| V3h4v  
**FileAccess.java ePq13!FC/  
*//文件访问(定位,写) JO2ZS6k[  
package NetFox; ^"O{o8l>2  
import java.io.*; +}7Ea:K   
j{{~ZM  
yV:EK{E  
public class FileAccessI implements Serializable{ 0%xR<<gir  
*L%6qxl`V  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *xE"8pN/  
RandomAccessFile oSavedFile; \7Gg2;TA6o  
long nPos; {W5ydHXy  
>=-GD2WK  
=tr1*s{  
public FileAccessI() throws IOException ~L%Pz0Gg  
{ NP K#].F  
this("",0); +}_Pf{MW  
} 1Pk mg%+  
$ Wit17j  
_0'm4?"  
public FileAccessI(String sName,long nPos) throws IOException {$EH@$./  
{ =n@F$/h  
oSavedFile = new RandomAccessFile(sName,"rw"); 1.# |QX  
this.nPos = nPos; C#MF pT  
oSavedFile.seek(nPos); #yW.o'S+  
} [YC=d1F5  
_W)`cr  
;i<$7MR.e  
public synchronized int write(byte[] b,int nStart,int nLen) W8w3~  
{ bTZ>@~$  
int n = -1; $.H:8^W  
try{ 3gb|x?  
oSavedFile.write(b,nStart,nLen); ?h/xAl  
n = nLen; CF]i}xpWV  
} >qR7'QwP  
catch(IOException e) 7#QLtU  
{ 7OB%A&  
e.printStackTrace (); y Wpi|  
} 41u*w2j  
kmryu=  
Lp_$?MCD.  
return n; #@9)h  
} z5x _fAT(  
*yJ[zXXjJ  
led))qd@V-  
} &~RR&MdZ2  
K&*iw`  
LH4>@YPGE#  
/* K*~]fy  
**SiteInfoBean.java ?a S%  
*/ m9Ax\lf  
package NetFox; CdY8 #+"  
]<1HM"D  
oizT-8i@N  
public class SiteInfoBean { c! @F  
U#bl=%bF  
#O"  
private String sSiteURL; //Site's URL wu A^'T  
private String sFilePath; //Saved File's Path $[g_=Z  
private String sFileName; //Saved File's Name O`WIkBV!  
private int nSplitter; //Count of Splited Downloading File >&OUGu|  
#/|75 4]]  
zrs<#8!Y_!  
public SiteInfoBean()  ?>af'o:  
{//nSplitter的缺省值为5 2R]&v;A  
//default value of nSplitter is 5 -D^L}b  
this("","","",5); EFAGP${F  
} =+Im*mgNn  
EeB ]X24  
4e +~.5r@i  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1"}cdq.  
{ Z?oG*G:  
sSiteURL= sURL; TI=h_%mO  
sFilePath = sPath; QYQtMb,  
sFileName = sName; (zG.aaz*C  
this.nSplitter = nSpiltter; .-0%6] cFD  
$6T3y8  
n 6{2]&sd  
} MM?`voj~`p  
Y>B P?l  
m 41t(i  
public String getSSiteURL() 'Hw4j:pS  
{ nBN&.+3t  
return sSiteURL; JQ@fuo %  
} Gih[i\%Q  
_tAQ=eBO  
&-%X:~|:X  
public void setSSiteURL(String value) P}V=*g  
{ k;I  &.H  
sSiteURL = value; EATu KLP\  
} 3$VxRz)  
N L'R\R  
HRB[GP+  
public String getSFilePath() fTq C:r|st  
{ o%[U  
return sFilePath; fj>C@p  
} fQ+\;iAU  
aE|OTm+@9;  
[Il~K  
public void setSFilePath(String value) u3J?bR  
{ T@[!A);  
sFilePath = value; f?56=& pHY  
} K=?VDN  
RKZ6}q1n  
C5W>W4EM  
public String getSFileName() b.F^vv"]]  
{ :?Y$bX}a  
return sFileName; 5\Fz!  
} {_#yz\j  
hXn3,3f3oZ  
YE}s  
public void setSFileName(String value) 4=Gph  
{ eKN$jlg  
sFileName = value; Bfr'Zdw  
} iWLa>z|,  
nmFC%p)4  
 npp[@*~  
public int getNSplitter() 9bJQT'<R  
{ '9?;"=6(  
return nSplitter; EE=3  
} ZH,4oF  
w$|l{VI  
bU54-3Ox*  
public void setNSplitter(int nCount) hWo=;#B*  
{ ]3Dl)[R  
nSplitter = nCount; ZJ,cQ+fn  
} Thr*^0$C  
} {g6Qv-  
;AJTytE>%  
*[+)7  
/* %Sk@GNI_  
**Utility.java v4Ga0]VN$8  
*/ <#+44>h  
package NetFox; &<pKx!  
($nrqAv4  
~8T(>!hE1h  
public class Utility { ,8MLoZ _  
BZv+H=b  
v"^~&q0x  
public Utility() w}R~C   
{ $gpG%Qj  
fyWO  
*&Lq!rFS  
} P u0uKE  
LjB;;&VCn  
//线程睡眠 8Q{9>^  
public static void sleep(int nSecond) l8h&|RY[  
{ o>/O++7Ra  
try{ c`*TPqw(B[  
Thread.sleep(nSecond); {yA$V0`N{  
} Q&'}BeUbm  
catch(Exception e) VOTv?Vf  
{ 7OCwG~_^  
e.printStackTrace (); ;Xvp6.:  
} _c$9eAe  
}  '1^B +m  
X^9d/}uTa  
//日志 fq[;%cr4  
public static void log(String sMsg) X|D!VX>#!  
{ l`-bFmpA  
System.err.println(sMsg); u{N,Ib 8  
} ;6ecrQMw&  
4)>FS'=  
KInk^`C/H  
public static void log(int sMsg)  y! .J  
{ Zk8|K'oHx  
System.err.println(sMsg); 6]zd.W  
} =qy=-j]  
} 4_v]O  
YwY74w:  
[+m?G4[  
/* vIl+#9L0  
**TestMethod.java so$(_W3E,  
*/ S& #U!#@  
package NetFox; ((tv2  
z7M_1%DEx  
.\0isO  
public class TestMethod { W|:lVAP.|}  
%ek'~  
Eodn/  
public TestMethod() sVk$x:k1M  
{ ///xx/weblogic60b2_win.exe 54-#QIx|  
try{ \#-W <  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :0)3K7Q   
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OA/WtQ5  
SiteFileFetch fileFetch = new SiteFileFetch(bean); |tR OL 9b  
fileFetch.start(); v:Tzv^  
} U7uKRv9  
catch(Exception e){e.printStackTrace ();} vx_o(wof  
+YLejjQ  
zA+~7;7E  
} /&F,V+x  
W>VP'vn}  
:1XtvH  
public static void main(String[] args) :l7U>~ o  
{ I1oje0$  
new TestMethod(); #_Z$2L"U  
} ?m$a6'2-,J  
} U j+j}C  
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