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http断点续传简单实现(java)

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/* Q'Osw"  
**SiteFileFetch.java W3/bM>1  
*/ 3J &R os  
package NetFox; dVEs^ZtI  
import java.io.*; eDZ8F^0  
import java.net.*; \?T9 v  
zHX\h [0f  
Fw\Z[nh  
public class SiteFileFetch extends Thread { ckA\{v  
iKJqMES  
rVNx 2  
SiteInfoBean siteInfoBean = null; //文件信息Bean b2UDPW  
long[] nStartPos; //开始位置 k !0O[U  
long[] nEndPos; //结束位置 ;6[6~L%K}  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 @GQfBV|3  
long nFileLength; //文件长度 j2_j5Hgo  
boolean bFirst = true; //是否第一次取文件 xS/W}-dPv  
boolean bStop = false; //停止标志 s!/lQo5/  
File tmpFile; //文件下载的临时信息 `M6"=)twu  
DataOutputStream output; //输出到文件的输出流 >aO.a[AM  
:QGo -,6-  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) b^ h_`  
public SiteFileFetch(SiteInfoBean bean) throws IOException a- rR`  
{ 9Sxr9FLW~  
siteInfoBean = bean; 6Qt(Yu*s  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); [_(J8~ va  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 'QT~o-U  
if(tmpFile.exists ()) kWZY+jyt P  
{ W{"sB:E  
bFirst = false; 018SFle  
read_nPos(); BA2"GJvfIA  
} )/;+aDk  
else _) x{TnK  
{ fOHbgnL>  
nStartPos = new long[bean.getNSplitter()]; &`l\Q\_[@  
nEndPos = new long[bean.getNSplitter()]; l1DJ<I2  
} g&xj(SMj-$  
@9HRGxJ=}  
nwKp8mfP  
(6ga*5<  
} OlRXgJ  
rxgSQ+G_  
$lf/Mg_H  
public void run() B\RAX#  
{ Zpkd8@g@  
//获得文件长度 iv~R4;;)  
//分割文件 x:MwM?  
//实例FileSplitterFetch s"=TM$Vb  
//启动FileSplitterFetch线程 SZ9Oz-?  
//等待子线程返回 >^jBE''  
try{ *zrGrk:l  
if(bFirst) X+XDfEt:Q  
{ ]|CcQ1#|H  
nFileLength = getFileSize(); Yvo*^jv  
if(nFileLength == -1) rwLKY .J]  
{ z!3=.D  
System.err.println("File Length is not known!"); Qy"Jt]O  
} e+lun -  
else if(nFileLength == -2) agx8 *x  
{ `CS\"|z  
System.err.println("File is not access!"); FE!jN-#  
} GLtWo+g0  
else ,6;n[p"h|r  
{ *pwkv7Z h  
for(int i=0;i<nStartPos.length;i++) 6^LXctW.  
{ ):G%o  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); O3o ^%0  
} Xs052c|s  
for(int i=0;i<nEndPos.length-1;i++) metn&  
{ mxgT}L0i  
nEndPos = nStartPos[i+1]; i#*[, P~  
} KBB)xez8  
nEndPos[nEndPos.length-1] = nFileLength; LRu,_2"  
} r89AX{:  
} /&Oo)OB;  
0Gs\x  
i;1pw_K  
//启动子线程 @FN|=?8%  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nKm# kb  
for(int i=0;i<nStartPos.length;i++) p [C 9g  
{ 0 MK}  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (&SU)Uvu  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~6t!)QATnp  
nStartPos,nEndPos,i); W 94:%  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %jjPs .  
fileSplitterFetch.start(); e&z@yy$  
} fY&TI}Y  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #!F>cez  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xA Ez1  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S<i1t[E @W  
nEndPos = " + nFileLength); IQO|)53)  
// fileSplitterFetch[nPos.length-1].start(); >g{&Qx`&  
Ih:Q}V#6  
dzOco)y  
//等待子线程结束 kku<0<(N  
//int count = 0; JI .=y5I  
//是否结束while循环 _s5^\~ao  
boolean breakWhile = false; }"TQ\v$  
[ *Dj:A)V^  
r5~ W/eE  
while(!bStop) @bA5uY!  
{ -fPiHKJ  
write_nPos(); 3UUdJh<~  
Utility.sleep(500); ^yPZ$Q  
breakWhile = true; !{^kH;*u  
VBL4cU8D  
wmGcXBHt$  
for(int i=0;i<nStartPos.length;i++) h_(M#gG  
{ Wz' !stcp  
if(!fileSplitterFetch.bDownOver) @G2# Z  
{ 0beP7}$  
breakWhile = false; .m]}Ba}J$  
break; > mO*.'Gm  
} pRun5 )7  
} 4tCM 2it%  
if(breakWhile) Vr},+Rj  
break; !4afU:  
csW\Q][  
9s"st\u 4  
//count++; < 9,h!  
//if(count>4) MG vz-E1e  
// siteStop(); )7*'r@  
} cK1^jH<|  
7G_<+rn  
 J| N 6r  
System.err.println("文件下载结束!");  "M5  
} CImp,k0  
catch(Exception e){e.printStackTrace ();} 8Ij<t{Lps  
} QZ&(e2z  
[cnu K  
Br9j)1;  
//获得文件长度 <Ja&z M  
public long getFileSize() 3l<qcKKc  
{ ?\8aT"o  
int nFileLength = -1; [<53_2]~  
try{ Eto"B"  
URL url = new URL(siteInfoBean.getSSiteURL()); YAc:QVT87  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <ZSXOh,'  
httpConnection.setRequestProperty("User-Agent","NetFox"); L4Jm8sy{  
jcqUY+T$  
M]PZwW8  
int responseCode=httpConnection.getResponseCode(); `TJhH<z"%  
if(responseCode>=400) ^ nPy(Q0  
{ Hq}g1?b  
processErrorCode(responseCode); /.0K#J:  
return -2; //-2 represent access is error mzK0$y #*o  
} i-wRwl4aEF  
!-}Q{<2@W  
'l^Bb#)"  
String sHeader; t?>}0\1  
+H3~Infr4f  
`;}`>!8j  
for(int i=1;;i++) B`-uZ9k   
{ Sn*s@RE\s  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "?zWCH  
//Utility.log(in.readLine()); zj r($?  
sHeader=httpConnection.getHeaderFieldKey(i); "a[;{s{{.  
if(sHeader!=null) qIuo8o}  
{ 3`reXms*{  
if(sHeader.equals("Content-Length")) u9f^wn  
{ v<v;ZR)  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }3: mn  
break; Nl YFS?5  
} *:H,-@  
}  <)TIj6  
else qkhre3  
break; {'4#{zmp  
} eWDXV-xD  
} uNn1qV  
catch(IOException e){e.printStackTrace ();} :o^ioX.J  
catch(Exception e){e.printStackTrace ();} nCi ]6;Y  
W5Z-s.o  
n' mrLZw  
Utility.log(nFileLength); SEI0G_wk$  
o>M^&)Xs  
myA;Y  
return nFileLength; e^eJ!~0  
} t}R!i-D|HB  
xH2'PEjFM  
r7W.}n*  
//保存下载信息(文件指针位置) l!:bNMd  
private void write_nPos() #k9&OS?  
{ tM"vIz 05  
try{ dQIF '==6  
output = new DataOutputStream(new FileOutputStream(tmpFile)); d=bK NA90  
output.writeInt(nStartPos.length); Oz%6y ri  
for(int i=0;i<nStartPos.length;i++) #|E#Rkw!  
{ 6ZI Pe~`  
// output.writeLong(nPos); A>gZl)c  
output.writeLong(fileSplitterFetch.nStartPos); S Q:H2vvD  
output.writeLong(fileSplitterFetch.nEndPos); "J,|),Yd  
} ouCh2Y/_  
output.close(); y 0p=E^Q M  
} M@es8\&S.  
catch(IOException e){e.printStackTrace ();} X>7Pqn'  
catch(Exception e){e.printStackTrace ();} bji#ID2]%  
} {oY"CZ2  
7=N%$]DKZ  
4C?{p%3c  
//读取保存的下载信息(文件指针位置) M%_*vD  
private void read_nPos() !f(A9V  
{ ]@9W19=P!P  
try{ PWS8Dpb  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); liYsUmjZ=  
int nCount = input.readInt(); Vw w 211  
nStartPos = new long[nCount]; Kq")|9=d  
nEndPos = new long[nCount]; 'G65zz  
for(int i=0;i<nStartPos.length;i++) dsw^$R}   
{ ?M'CTz}<\  
nStartPos = input.readLong(); wm#(\dj  
nEndPos = input.readLong(); -I{op wd  
} JYNn zgd  
input.close(); #tZ!D^GQHq  
} 6%p6BK6  
catch(IOException e){e.printStackTrace ();} ?:/J8s [O  
catch(Exception e){e.printStackTrace ();} ]uFJ~ :R  
} Gs"lmX-{$j  
|rJN  
W2XWb<QSEV  
private void processErrorCode(int nErrorCode) :a Cf@:']  
{ yI8 O#  
System.err.println("Error Code : " + nErrorCode); TkTGYh  
} fASklcQ  
{s@!N  
Ydsnu  
//停止文件下载 Q#yHH]U)X  
public void siteStop() 1^o})9  
{ 2n>mISy+  
bStop = true; }2LG9B%  
for(int i=0;i<nStartPos.length;i++) fV4eGIR&  
fileSplitterFetch.splitterStop(); vULDKJNHX  
xKL(:ePS  
C4E}.``Hm  
} aT2%Az@j  
} <P1nfH  
//负责部分文件的抓取 R5b,/>^'A  
**FileSplitterFetch.java pqs!kSJV  
*/ uD{-a$6z  
package NetFox; ;PMPXN'z6  
%62|dhl6  
 ^4WZ%J#g  
import java.io.*; A?HDY_u  
import java.net.*; #vK99 S2  
EIzTbW{p  
ISZEP8w  
public class FileSplitterFetch extends Thread { ^Vth;!o  
t@lTA>;U@  
" AvEo  
String sURL; //File URL rYPuo  
long nStartPos; //File Snippet Start Position n.N0Nhd  
long nEndPos; //File Snippet End Position sifjmNP  
int nThreadID; //Thread's ID &56\@t^  
boolean bDownOver = false; //Downing is over 9Q(Lnu  
boolean bStop = false; //Stop identical zz3{+1w]  
FileAccessI fileAccessI = null; //File Access interface vB7]L9=@"  
w`boQ_Ir  
Y_$!XIJ4  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )LG!"~qiz  
{ )5`^@zx  
this.sURL = sURL; zLr:zfl  
this.nStartPos = nStart; ~yN>9f U  
this.nEndPos = nEnd; b6e 2a/x  
nThreadID = id; HHyN\  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g[b;1$  
} pPsTgGai  
`Q+O#l?  
hHMp=8J7  
public void run() X..M!3W  
{ hT =E~|O  
while(nStartPos < nEndPos && !bStop) O:V.;q2]U  
{ *W |  
Q.4+"JoG  
7zQGuGo(  
try{ D@w&[IF  
URL url = new URL(sURL); /FTP8XHwL)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mtFC H  
httpConnection.setRequestProperty("User-Agent","NetFox"); meB9 :w[m  
String sProperty = "bytes="+nStartPos+"-"; #?M[Q:  
httpConnection.setRequestProperty("RANGE",sProperty); p/ZgzHyF  
Utility.log(sProperty); Y]&2E/oc  
A\/DAVnI  
IwXQbJ3v_  
InputStream input = httpConnection.getInputStream(); )q!dMZ(  
//logResponseHead(httpConnection); vG}\Amx+  
sWA-_4  
\ Ho VS  
byte[] b = new byte[1024]; N}z]OvnZH  
int nRead; N^`S'FVA  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9@ h-q(-  
{ V?MaI .gj  
nStartPos += fileAccessI.write(b,0,nRead); 0^P9)<k'  
//if(nThreadID == 1) A@.ruG$  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?)qm=mebY  
} 5 a&a-(  
Jk<b#SZ[b  
v>hc\H1P  
Utility.log("Thread " + nThreadID + " is over!"); hsws7sH  
bDownOver = true; JDpW7OrDc  
//nPos = fileAccessI.write (b,0,nRead); #)DDQ?D  
} ayf;'1  
catch(Exception e){e.printStackTrace ();} q|B.@Ng.  
} $f"Ce,f  
} _}H`(d%N  
<aMihT)dd  
's8LrO(=  
//打印回应的头信息 d8jP@>  
public void logResponseHead(HttpURLConnection con) j}%C;;MPH  
{ c@O7,y:`I  
for(int i=1;;i++) O[}2  
{ >\Iy <M  
String header=con.getHeaderFieldKey(i); Em<J{`k6  
if(header!=null) XC[AJ!q`  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BYI13jMH+Y  
Utility.log(header+" : "+con.getHeaderField(header)); _A$V~Hp9q  
else 7bW ''J*6  
break; dr=KoAIxy  
} .GDY J9vi  
} nzi)4"3O  
:=`N2D  
=5p?4/4 J  
public void splitterStop() hG/Z65`&  
{ |msQ  
bStop = true; dBL{Mbh2Z  
} o[G,~f\-  
P-N+  
U,2\ TBz  
} 44hz,  
40LA G  
B&lF! ]  
/* }PzYt~Z`@  
**FileAccess.java =H^^AG\}  
*//文件访问(定位,写) mhnK{M @56  
package NetFox; W-"FRTI4  
import java.io.*; P4"EvdV7  
}'TZ)=t{J  
75H5{#)  
public class FileAccessI implements Serializable{ A$'rT|>se  
9TE-'R@  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节  7w|4BRL  
RandomAccessFile oSavedFile; FU(s jB  
long nPos; #w]:<R^  
ZsDn`8  
#kEa&Se  
public FileAccessI() throws IOException VV~Kgy  
{ 7G8M+i3q/  
this("",0); 8!dA1]2;  
} ^p7Er!  
e,0Gc-X[B  
dzc.s8T(0  
public FileAccessI(String sName,long nPos) throws IOException 5zI I4ukn*  
{ b"#|0d0  
oSavedFile = new RandomAccessFile(sName,"rw"); )x&}{k6 %  
this.nPos = nPos; e0u* \b  
oSavedFile.seek(nPos); $30lNZK1m8  
} Y]1b3 9O  
)e:u 6]  
uJHf6Ye  
public synchronized int write(byte[] b,int nStart,int nLen) >RT02Ey>  
{ n&uD=-  
int n = -1; @k2nID^>  
try{ }3mIj<I1;  
oSavedFile.write(b,nStart,nLen); ]2B=@V t,  
n = nLen; a?9Ka!O4s  
} >&N8Du*[  
catch(IOException e) M&O .7B1}  
{ w6l8RNRe  
e.printStackTrace (); 1QH5<)Oa  
} {wp"zaa  
owc#RW9 7  
;GxKPy  
return n; '=vD!6=0@  
} ng[ZM);  
'Sjcm@ILm  
~I)\d/7o  
} Vg4N7i  
6~0. YZ9  
/\M3O  
/* 0 /JusQ  
**SiteInfoBean.java :Keek-E`e=  
*/ !pLQRnI}6  
package NetFox; Li_ a|dI  
x5}Ru0Z  
3 a G?^z  
public class SiteInfoBean { %t^-Guz  
HGpj(U:`c  
"(rG5z3P  
private String sSiteURL; //Site's URL NrdbXPHceN  
private String sFilePath; //Saved File's Path .DSmy\FI5  
private String sFileName; //Saved File's Name {` Lem  
private int nSplitter; //Count of Splited Downloading File %<w)#eV?  
']ussFaQ  
`PR)7}/<  
public SiteInfoBean() aJ1<X8  
{//nSplitter的缺省值为5 n089tt=TE  
//default value of nSplitter is 5 !bG%@{WT  
this("","","",5); />z E$)'M  
} a:tCdnK/  
jn9KQe\3  
iWZrZ5l  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V '4sOn  
{ Q}M% \v  
sSiteURL= sURL; r0)X]l7  
sFilePath = sPath; \j]i"LpWb  
sFileName = sName; }?=$?3W  
this.nSplitter = nSpiltter; .* xaI+:  
wh@;$s"B  
SablF2doa  
} BVX6  
&i,xod6$  
;X ]+r$_  
public String getSSiteURL() dk9'C  
{ }Q?, O  
return sSiteURL; "-+5`!Y  
} j\D_Z{m2  
|BGQ|7DyG  
hX~d1.]Y  
public void setSSiteURL(String value) y pv~F  
{ OFTyN^([@  
sSiteURL = value; }Zue?!KQ  
} I|*w?i*  
Oozt&* F  
YULI y-W  
public String getSFilePath() 0m^(|=N-  
{ #%xzy@`  
return sFilePath; ew# t4~hh  
} WCc,RI0   
%># VhK  
%(IkUD  
public void setSFilePath(String value) 9"3 7va  
{ YzqUOMAt"V  
sFilePath = value; I65W^b4y  
} gUs.D_*  
0?KY9  
ua%$r[  
public String getSFileName() SM2QF  
{ P\B ]><!ep  
return sFileName; p^~ AbU'6~  
} qcSlY&6+  
JgJ4RmH-  
0HA`  
public void setSFileName(String value) eot]VO:  
{ g?.ls{H  
sFileName = value; 3?F*|E_  
} XjL)WgQ{i  
dBKL_'@@}  
pPSmSWD?  
public int getNSplitter() Lj"@JF;c  
{ t%$>  
return nSplitter; ]uN}n;`12  
} r%*,pN7O  
uz6S7I  
Tji G!W8  
public void setNSplitter(int nCount) qU(,q/l  
{ YL_M=h>P  
nSplitter = nCount; |N%?7PZ(  
} fz[o;GTc  
} ]o18oY(  
#"J8]3\F  
3":vjDq$  
/* U_t[J|  
**Utility.java .tv'`  
*/ /gWaxR*m  
package NetFox; 6;WfsG5  
uHj"nd13  
OT[&a6_  
public class Utility { o}q>oa b z  
+{(f@,&~{  
ZS*PY,  
public Utility() ,%>]  
{ @N,(82k  
?RyeZKf  
&M p??{g  
} 5G!0Yy['  
>/@wht4- j  
//线程睡眠 Ah5`Cnv  
public static void sleep(int nSecond) -][~_Hd{  
{ SvZ~xTit  
try{ ^O#>LbM"x  
Thread.sleep(nSecond); M3m!u[6|  
} N~rA/B]T  
catch(Exception e) 0!<qfT a  
{ TR;"&'#k  
e.printStackTrace (); or~2r8  
} }HB>Zb5  
} 3q'["SS  
{k CCpU  
//日志 a_jw4"Sb  
public static void log(String sMsg) |\/`YRg>  
{ gEghDO_G  
System.err.println(sMsg); 00jWs@K  
} Q&j-a;L  
g=)B+SY'  
%b 8ig1  
public static void log(int sMsg) 7+_TdDBYs  
{ }q<p;4<\F  
System.err.println(sMsg); 0&M~lJ  
} `fTH"l1zn  
} "Y%fk/v8  
'%Cc!63t*  
S#h-X(4  
/* ~ _ ogeD  
**TestMethod.java 2/XrorV  
*/ ''t\J^+&  
package NetFox; bSa%?laS  
} Xbmb8  
%r E:5)  
public class TestMethod { tuT>,BbR  
k P]'  
3jSt&+  
public TestMethod() I+08tXO  
{ ///xx/weblogic60b2_win.exe pco:]3BF6  
try{ G>siyUh  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s fD@lW3  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); S vTd#>ke  
SiteFileFetch fileFetch = new SiteFileFetch(bean); #mT\B[4h  
fileFetch.start(); .r ,wc*SF  
} Pz\4#E]  
catch(Exception e){e.printStackTrace ();} (G1KMy  
8jBrD1  
@:,B /B;  
} f.yvKi.Cm  
k^VL{z:EWB  
,> Ya%;h2k  
public static void main(String[] args) zR@4Z>6   
{ azhilUD8  
new TestMethod(); \#50; 8VJ  
} ~F [V  
} [ TX1\*W  
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