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http断点续传简单实现(java)

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/* I,{YxY[$7  
**SiteFileFetch.java {]T?)!V m  
*/ @Vre)OrN#  
package NetFox; 0<uek  
import java.io.*; 6O7s^d&K  
import java.net.*; Wo 1x ZZ  
=SfNA F  
s<s}6|Z  
public class SiteFileFetch extends Thread { 8=`L#FkRp  
).SJ*Re*^I  
k QuEG5n.-  
SiteInfoBean siteInfoBean = null; //文件信息Bean R~\R>\  
long[] nStartPos; //开始位置 =yf) Z^  
long[] nEndPos; //结束位置 s@F&N9oh  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 r)*23&Ojs  
long nFileLength; //文件长度 !D#"+&&G8  
boolean bFirst = true; //是否第一次取文件 .AfZ5s]/F  
boolean bStop = false; //停止标志 cFUD$mp  
File tmpFile; //文件下载的临时信息 &lQ%;)'  
DataOutputStream output; //输出到文件的输出流 'ToE Y3  
y[8;mCh  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) D'g,<-ahl  
public SiteFileFetch(SiteInfoBean bean) throws IOException NKu[6J?)  
{ wjA wJOw|  
siteInfoBean = bean; >JyS@j}  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); H7zN|NdNw  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); jRJG .hcB5  
if(tmpFile.exists ()) xZ'fer`&  
{ 'C1lP)S5  
bFirst = false; ytZo0pad  
read_nPos(); P.Z:`P)  
} $w0TEO!  
else $DY#04Je\=  
{ Jo5Bmh0  
nStartPos = new long[bean.getNSplitter()]; U#jz5<r  
nEndPos = new long[bean.getNSplitter()]; @/ z\p7e  
} M@Th^yF+8H  
:o s8"  
\P<aK$g  
5Gz!Bf@!!  
} 2S?7j[@%i`  
>,e^}K}C  
=;Gq:mHi  
public void run() Vrt$/ d  
{ F9fLJol  
//获得文件长度 5,"c1[`-  
//分割文件 2 XP }:e  
//实例FileSplitterFetch fiGTI}=P  
//启动FileSplitterFetch线程 UA>=# $  
//等待子线程返回 u]yy%@U1  
try{ "q=Cye  
if(bFirst) (dy(.4W\  
{ Q{[@n  
nFileLength = getFileSize(); >q"dLZ  
if(nFileLength == -1) `i.BB jx`  
{ ,mHME~  
System.err.println("File Length is not known!"); Y^fw37b  
} -DI >O/  
else if(nFileLength == -2) GX>8B:]o|  
{ m5K?oV@n  
System.err.println("File is not access!"); 9&lemz  
} W$4$%r8  
else Coi[cfg0  
{ 0<,{poMM  
for(int i=0;i<nStartPos.length;i++) mTZ/C#ir(  
{ 6TP /0o)  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); O$*lPA[  
} 6{h\CU}"  
for(int i=0;i<nEndPos.length-1;i++) J"`VA_[  
{ z`{sD]  
nEndPos = nStartPos[i+1]; `3;EJDEdbi  
} l6  G6H$  
nEndPos[nEndPos.length-1] = nFileLength;  LA3m,  
} F>fCp  
} j-<-!jTd  
O_FB^BB  
Nk'<*;e  
//启动子线程 4MgN  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5vx 4F f  
for(int i=0;i<nStartPos.length;i++) msl.{  
{ W A/dt2D|  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A@A8xn%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;uBGB h<  
nStartPos,nEndPos,i); w1/QnV  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oD2:19M@p  
fileSplitterFetch.start(); _{[6hf4p  
} x[0T$  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nWd!ovd  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); htBA.eQ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dyQ7@K.E  
nEndPos = " + nFileLength); k2}DBVu1  
// fileSplitterFetch[nPos.length-1].start(); G6G Bqp6|  
%e iV^>  
@ {/)k%U  
//等待子线程结束 V]H(;+^P  
//int count = 0; .?Eb{W)^br  
//是否结束while循环 ynI e4b  
boolean breakWhile = false; ]A5F}wV4  
z !K2UTX  
7HPwlS  
while(!bStop) jSI1tW8  
{ };Q}C0E  
write_nPos(); vjEDd`jYZ  
Utility.sleep(500); 7:4c\C0  
breakWhile = true; 7`|'Om?'  
|Z:yd}d  
MBWoPK  
for(int i=0;i<nStartPos.length;i++) LU6R"c11  
{ \e86'&  
if(!fileSplitterFetch.bDownOver) (0{Dn5MH  
{ vk7IqlEQ  
breakWhile = false; K[T0);hZR  
break; VVJ0?G (?  
} j7}mh  
} 5rsz2;#p  
if(breakWhile) ufXWK3~\  
break; "Bd-h|J  
9g6$"',H  
[ V.67_~  
//count++; OyO<A3  
//if(count>4) /~,*DH$)  
// siteStop(); Ao K9=F}  
} <"3q5ic/Z  
[jgVN w""D  
hK?GIbRZ  
System.err.println("文件下载结束!"); "r^RfZ;  
} a%%7Ew ?  
catch(Exception e){e.printStackTrace ();} - Jaee,P  
} ZF7n]LgSc&  
g QBS#NY  
T+Yv5l  
//获得文件长度 dz^HN`AlzC  
public long getFileSize() }qWnn>h9xv  
{ KI9Pw]]{-  
int nFileLength = -1; 9PB%v.t5 y  
try{ |f_'(-v`E  
URL url = new URL(siteInfoBean.getSSiteURL()); c.>f,vtcn  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >Na.C(DZ  
httpConnection.setRequestProperty("User-Agent","NetFox"); &M|rRd~*  
/stvNIEa  
8a6.77c  
int responseCode=httpConnection.getResponseCode(); xp|1yud  
if(responseCode>=400) ^Mq/Cf_T  
{ gC$_yd6m L  
processErrorCode(responseCode); @qNY"c%HV  
return -2; //-2 represent access is error By1T um+I1  
} c7CYulm  
.gO|=E"  
+$C9@CZM9  
String sHeader; %R GZu\p  
o*K7(yUL4  
0>Y3xNb  
for(int i=1;;i++) |k}<Zz1UM  
{ K~:SLCv E%  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4)iP%%JH  
//Utility.log(in.readLine()); %pVsafV  
sHeader=httpConnection.getHeaderFieldKey(i); "}()/  
if(sHeader!=null) ';R]`vWFe  
{ 2TGND-(j  
if(sHeader.equals("Content-Length")) .>W [  
{ lJ3VMYVrUP  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;!f='QuA  
break; jU-LT8y:  
} 6%V:Z  
} .]E(P   
else `,4yGgD!4  
break; |&K;*g|a  
} h; q&B9  
} RQ=rB9~:ZN  
catch(IOException e){e.printStackTrace ();} //NV_^$y  
catch(Exception e){e.printStackTrace ();} A.*e8a/6X  
.6MG#N  
/)[-5n{  
Utility.log(nFileLength); lL zR5445)  
6wpW!SWD  
kk5&lak2V  
return nFileLength;  8s22VL  
} k2eKs*WLC  
6"iNh)  
9Qszr=C0  
//保存下载信息(文件指针位置) kb 74:  
private void write_nPos() u>;aQtK~  
{ <yl@!-'J7  
try{ 6n/=n%US  
output = new DataOutputStream(new FileOutputStream(tmpFile)); i\lvxbp  
output.writeInt(nStartPos.length); ]]y>d!  
for(int i=0;i<nStartPos.length;i++) z?13~e[D  
{ ], Bafz)4  
// output.writeLong(nPos); <e#v9=}DI  
output.writeLong(fileSplitterFetch.nStartPos); 4U\>TFO  
output.writeLong(fileSplitterFetch.nEndPos); ac\aH#J_nC  
} Qe F:s|[  
output.close(); 'bRf>=  
} N5)H(<}  
catch(IOException e){e.printStackTrace ();} Yt*NIwWr  
catch(Exception e){e.printStackTrace ();} W/A@qo"  
} Q1Qw45$  
)'jGf;du  
]*]*O|w  
//读取保存的下载信息(文件指针位置) N5l`Rq^K  
private void read_nPos() N @_y<7#C  
{ o#"yFP1  
try{ #IGcQY  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8\E=p+C  
int nCount = input.readInt(); XR8`,qH>  
nStartPos = new long[nCount]; sRLjKi2D  
nEndPos = new long[nCount]; b&A/S$*  
for(int i=0;i<nStartPos.length;i++) ?r =`Kl  
{ c\[&IlM  
nStartPos = input.readLong(); N6kMl  
nEndPos = input.readLong(); !!A(A^s  
} |H=5Am  
input.close(); mx1Bk9h%Xe  
} >=rniHs=?7  
catch(IOException e){e.printStackTrace ();} ~YNzSkz  
catch(Exception e){e.printStackTrace ();} A##Q>|>)  
} :9 &@/{W  
E\Wd*,/v)  
ph)=:*A6&  
private void processErrorCode(int nErrorCode) zxs)o}8icO  
{ x$Wtkb0<  
System.err.println("Error Code : " + nErrorCode); aiX4;'$x!  
} wmK;0 )|H  
PRYm1Y  
4]zn,g?&  
//停止文件下载 RKMF?:  
public void siteStop() )y!gApNs"  
{ oT:w GBW  
bStop = true; 6_8yQ  
for(int i=0;i<nStartPos.length;i++) 8>|4iT  
fileSplitterFetch.splitterStop(); 8DD1wK\U~  
#6y fIvap  
{?w *n_T.  
} Ac*)z#H  
} Grw[h  
//负责部分文件的抓取 2fayQY xD  
**FileSplitterFetch.java %26HB w=JF  
*/ <b4} B   
package NetFox; _;x`6LM  
aFnyhu&W'  
?=?*W7  
import java.io.*; \2f?)id~  
import java.net.*; d hg($m  
B\|^$z2  
T z:,l$  
public class FileSplitterFetch extends Thread { .1h\r, #  
4 y.' O  
MjBI1|*  
String sURL; //File URL Vl(id_~_  
long nStartPos; //File Snippet Start Position b*Hk} !qH  
long nEndPos; //File Snippet End Position b!QRD'31'j  
int nThreadID; //Thread's ID ,DW q  
boolean bDownOver = false; //Downing is over Rc@lGq9  
boolean bStop = false; //Stop identical Z@JTZMN_  
FileAccessI fileAccessI = null; //File Access interface LEg|R+ 6E  
.ezko\nU  
b V_<5PHP  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rCGKE`H  
{ Q[!?SSX%  
this.sURL = sURL; D!)h92CIDm  
this.nStartPos = nStart; P$O@G$n  
this.nEndPos = nEnd; =L"I[  
nThreadID = id; e=tM=i"  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z0~,cO8~  
} e v7A;;  
Nb0T3\3W  
fA V.Mj-  
public void run() VK%ExMSqEh  
{ PJKxh%J  
while(nStartPos < nEndPos && !bStop) tOj5b 7'ui  
{ :-2sKD y  
uW(Ngcpr  
C3<_0eI  
try{ w(M i?  
URL url = new URL(sURL); 6!U~dt#a  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VzM (u _)  
httpConnection.setRequestProperty("User-Agent","NetFox"); L'a s^Od  
String sProperty = "bytes="+nStartPos+"-"; je:J`4k$  
httpConnection.setRequestProperty("RANGE",sProperty); |<8g 2A{X  
Utility.log(sProperty); 2fm6G).m  
ZTGsZ}{5   
tQMz1$  
InputStream input = httpConnection.getInputStream(); > JTf0/  
//logResponseHead(httpConnection); dDYor-g>  
sWq}/!@&  
-|czhO)R  
byte[] b = new byte[1024]; F9IPA%  
int nRead; $reQdN=~  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0KZsWlD:L  
{ cnDBT3$~Z  
nStartPos += fileAccessI.write(b,0,nRead); naY#`xig  
//if(nThreadID == 1) nrTCq~LO(  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2Y}A9Veb  
} esv<b>`R  
`1 Tg8  
}V+&o\4  
Utility.log("Thread " + nThreadID + " is over!"); M7gqoJM'Q  
bDownOver = true; m}m|(;T  
//nPos = fileAccessI.write (b,0,nRead); {X\FS   
} |z)7XK  
catch(Exception e){e.printStackTrace ();} O4W 2X@  
} XQ Si  
} X=k|SayE8  
kgX"I ?>d  
0M}Ql5+h,  
//打印回应的头信息 i8/"|+Z  
public void logResponseHead(HttpURLConnection con) Je#3   
{ lb)i0`AN+  
for(int i=1;;i++) eA9r M:  
{ @^Kw\s  
String header=con.getHeaderFieldKey(i); QSo48OFs  
if(header!=null) [!#;QQ&M  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m`,h nDp  
Utility.log(header+" : "+con.getHeaderField(header)); (bogAi3<F  
else  ZN;fDv  
break; ;Ac!"_N?7  
} zL+M-2hV  
} $O9#4A;  
M[Jy?b)  
!;U}ax;AF  
public void splitterStop() I"jub kI=Z  
{ WODgG@w  
bStop = true; VBu6,6  
} 0mT.J~}1v  
qUNXT  
p#dYNed]'  
} ^s/f.#'  
0^MRPE|f5  
M`G#cEc  
/* 74~ %4  
**FileAccess.java Xu[A,6  
*//文件访问(定位,写) o l+*Oe  
package NetFox; Oyjhc<6  
import java.io.*; eKqo6P:#f  
f:A1j\A?  
*i7|~q/u  
public class FileAccessI implements Serializable{ 0 !F! Y_  
14Jkr)N  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w 5Yt mnP  
RandomAccessFile oSavedFile; `HM?Fc58  
long nPos; -sk!XWW+  
#Ic-?2Gn4<  
~w$ ^`e!]  
public FileAccessI() throws IOException LZ~}*}jy  
{ meyO=>  
this("",0); I6 Q{ Axy  
} :W1B"T<  
4"%LgV`  
M[ ,:NE4H  
public FileAccessI(String sName,long nPos) throws IOException 09HqiROw  
{ D +9l$**a  
oSavedFile = new RandomAccessFile(sName,"rw"); *f+DV[DF  
this.nPos = nPos; <a%RKjQvT  
oSavedFile.seek(nPos); {cAGOxwd  
} k iY1  
>o!~T}J7  
J?bx<$C@  
public synchronized int write(byte[] b,int nStart,int nLen) ,A!0:+  
{ p+1kU1F0  
int n = -1; .|3&lb6  
try{ vHx[:vuq:  
oSavedFile.write(b,nStart,nLen); A]s|"Pav,  
n = nLen; ^9?IS<N0]  
} p#AQXIF0  
catch(IOException e) kR;Hb3hb  
{ V3> JZH`  
e.printStackTrace (); 4#w Z#}  
} T [2l32  
yK:b $S  
b*"%E, ?  
return n; +T]D\];D  
} X?OH//co  
.0'FW!;FV  
7F wo t&  
} |]x>|Z?/u  
</jTWc'}  
qgw)SuwW  
/* 77p8|63  
**SiteInfoBean.java pu6@X7W"  
*/ pK@8= +  
package NetFox; i}r|Zo  
ORo,.#<  
- 1tiy.^$F  
public class SiteInfoBean { L+2<J,   
Ex$i8fO(  
o) ,1R:  
private String sSiteURL; //Site's URL jZ>x5 W  
private String sFilePath; //Saved File's Path F>[T)t{m=  
private String sFileName; //Saved File's Name y` 6!Vj l  
private int nSplitter; //Count of Splited Downloading File YS+|n%?  
zqa7!ky  
FWDAG$K@0  
public SiteInfoBean() C{U"Nsu+1  
{//nSplitter的缺省值为5 'o]8UD(  
//default value of nSplitter is 5 zP|^) h5  
this("","","",5); Y4I;-&d's  
} 58o'Q  
(od9adSehV  
*t,1(Gw|7q  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,\=,,1_  
{ n]fMl:77  
sSiteURL= sURL; w j<fi  
sFilePath = sPath; w>h\643  
sFileName = sName; cCbZ*  
this.nSplitter = nSpiltter; M)j.Uu  
 &'<e9  
YGf<!  
} cMp#_\B  
8a3h)R  
6h:2,h pE  
public String getSSiteURL() Av_JcH  
{ j NkobJ1  
return sSiteURL; fKOC-%w  
} gis;)al  
GX ;~K  
'nSo0cyQ  
public void setSSiteURL(String value) k}FmdaPI'  
{ =WM^i86  
sSiteURL = value; 6-J%Z%yT #  
} 6g&Ev'  
u@pimRVo  
g}n-H4LI  
public String getSFilePath() db`L0JB  
{ XsbYWJdds  
return sFilePath; `A ^  
} ME.a * v  
6,a:s:$>}R  
dh S7}n  
public void setSFilePath(String value) xY>@GSO1  
{ rc`}QoB)R  
sFilePath = value; _UGR+0'Q\  
} jiqE^j3;  
!N'HL-oT  
|Q?^Ba  
public String getSFileName() XDohfa _  
{ }ej>uZVe<  
return sFileName; &hu>yH>j  
} ~kFL[Asnaf  
!\5w<*p8  
liU8OXBl  
public void setSFileName(String value) &OsO _F  
{ <sli!rv  
sFileName = value; 3>QkO.b  
} #%7)a;'  
(5a:O (\r  
dTZ$92<  
public int getNSplitter() c8 Je&y8  
{ 1Y'NG<d _  
return nSplitter; H5>?{(m  
} a&RH_LjM  
)9i$ 1"a(  
MUn(ZnQy|  
public void setNSplitter(int nCount) |ya.c\}q  
{ ohna1a^  
nSplitter = nCount; qsWy <yL+  
} 75^AO>gt   
} 5D eo}(3  
ez<V  
2"6bz^>}  
/* ]Bj2;<@y  
**Utility.java LS]0p#  
*/ sOVU>tb\'  
package NetFox; y #zO1Nig`  
Z5|BwM  
);;UA6CD  
public class Utility { T:Nc^QP|tm  
z3I |jy1  
/V GI@"^v  
public Utility() uH]oHh!}j  
{ ny1;]_X_  
pZz\o  
[ylRq7^e  
} 7YFEyX10d  
/mXxj93UA  
//线程睡眠 lFl(Sww!\  
public static void sleep(int nSecond) # /Bg5:  
{ EKus0"|  
try{ 2Gh&h(  
Thread.sleep(nSecond); lg +>.^7k  
} R*/s#*gmL  
catch(Exception e) F3[,6%4v  
{ Q[{RN ab  
e.printStackTrace (); 5]xSK'6W  
} niqknqW<t  
} $*;`$5.x^  
"+E\os72|  
//日志 _iL?kf  
public static void log(String sMsg) )2a)$qx;  
{ ]I_*+^?tI  
System.err.println(sMsg); aW-6$=W  
} Wdi`Z E  
0SDnMij&bf  
"VDMO^  
public static void log(int sMsg) Al=ByX@  
{ ``%yVVg}  
System.err.println(sMsg); -9::M}^2  
} k%BU&%?1  
} .,20_<j%=  
#q 4uS~  
d f!i}L  
/* ^t:dcY7  
**TestMethod.java 2RQ- L  
*/ Wy%FF\D.Y  
package NetFox; 6$[7hlE  
U*b7 Pxq;  
Z?xRSi2~7  
public class TestMethod { IVY)pS"pR"  
| kP utB  
u"4 B5D  
public TestMethod() Evd|_W-  
{ ///xx/weblogic60b2_win.exe n*Uk<_WA  
try{ )U=]HpuzI  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =3 Vug2*wd  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K_@?Q@#YhR  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $xWUzg1<U  
fileFetch.start(); <Se9 aD  
} K{{_qFj@<y  
catch(Exception e){e.printStackTrace ();} *~>p;*  
GbclR:G  
7f4O~4.[i  
} :eSsqt9]9  
$rI 1|;^  
Fn7OmxfD  
public static void main(String[] args) Qn,6s%n  
{ _&/ {A|n  
new TestMethod(); a6-.|tt#t  
} r0 )ne|&Hp  
} 1Dl6T\20  
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