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http断点续传简单实现(java)

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/* /]@1IC{Lk  
**SiteFileFetch.java x[dR5  
*/ YK V?I   
package NetFox; ^fq^s T.$  
import java.io.*; v{44`tR   
import java.net.*; x,rK4L7U  
t)__J\xF  
Ui43&B  
public class SiteFileFetch extends Thread { N0POyd/rL  
 D_D76  
!*1Kjg3  
SiteInfoBean siteInfoBean = null; //文件信息Bean \YZ7  
long[] nStartPos; //开始位置 TilCP"(6D  
long[] nEndPos; //结束位置 E8LZ% N#  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 6dlV:f_\y  
long nFileLength; //文件长度 Kwmtt  
boolean bFirst = true; //是否第一次取文件 F39H@%R  
boolean bStop = false; //停止标志 921m'WE  
File tmpFile; //文件下载的临时信息 M}Obvl  
DataOutputStream output; //输出到文件的输出流 O+w82!<:  
^lP;JT?  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) N7l`-y  
public SiteFileFetch(SiteInfoBean bean) throws IOException 6M^NZ0~J  
{ _B6W:k|-7l  
siteInfoBean = bean; W3E7y?  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); /9o gg  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); cqSo%a2  
if(tmpFile.exists ()) NSV;R~"  
{ gZW(z  
bFirst = false; >gSiH#>  
read_nPos(); 7mT iO?/y<  
} TYH4r q &  
else  {Yc#XP  
{ EU,f;H  
nStartPos = new long[bean.getNSplitter()]; l6~wm1vO  
nEndPos = new long[bean.getNSplitter()]; *2^+QKDG  
} S"Z.M _  
$9@jV<Q1  
]; Z[V  
<oKoz0!  
} 8ZN"-]*  
!+H)N  
>X58 zlxk  
public void run() sgfci{~  
{ 9h/JW_  
//获得文件长度 30fqD1_{  
//分割文件 ?qJt4Om  
//实例FileSplitterFetch LLD#)Jl{?  
//启动FileSplitterFetch线程 [yn\O=%5  
//等待子线程返回 J-U5_>S  
try{ /t|Lu@&:Xo  
if(bFirst) HOSt0IHzty  
{  c_ Dg0  
nFileLength = getFileSize(); bD:[r))#e  
if(nFileLength == -1) $GJuS^@%  
{ \ 3XG8J  
System.err.println("File Length is not known!"); Cw$7d:u  
} r- 8fvBZ5  
else if(nFileLength == -2) )[np{eF.k  
{ {7Qj+e^  
System.err.println("File is not access!"); yLgv<%8f  
} oU)Hco"_k  
else 08MY=PC~R  
{ (,XbxDfM  
for(int i=0;i<nStartPos.length;i++) d9Uv/VGp  
{ N_liKhq  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ~m6b6Aj@6  
} ttd ^jT  
for(int i=0;i<nEndPos.length-1;i++) TJ_pMU  
{ qx f8f  
nEndPos = nStartPos[i+1]; VXP@)\!  
} @aC9O 9|~  
nEndPos[nEndPos.length-1] = nFileLength; |E?,hTRe5  
} 4r tNvf5`  
} y"T(Unvc  
KJYcP72P  
,p)Qu%'  
//启动子线程 12o6KVV^x  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <X "_S'O  
for(int i=0;i<nStartPos.length;i++) 4d63+iM+}  
{ ]9lR:V sw  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o XFo  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), epGC Ta  
nStartPos,nEndPos,i); IcJQC  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PdqyNn=  
fileSplitterFetch.start(); ZE:!>VXa87  
} QruclNW{Bv  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /I48jO^2  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {JlSfJw !  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qtlcY8!  
nEndPos = " + nFileLength); sIzy/W0iV  
// fileSplitterFetch[nPos.length-1].start(); M{4U%lk  
{v,NNKQ4x  
3Q!)bMv \  
//等待子线程结束 3XSfXS{lwP  
//int count = 0; oYAHyCkVq  
//是否结束while循环 r?2J   
boolean breakWhile = false; ` #; "  
3,^.  
ngOGo =  
while(!bStop) KXT9Wt=  
{ ni?5h5-  
write_nPos(); C17$ qdV/  
Utility.sleep(500); RMs+pN<5  
breakWhile = true; Ny5$IIF e  
%V|n2/O Y  
/2>.*H_2  
for(int i=0;i<nStartPos.length;i++) NnRX0]  
{ ~s2la~gu  
if(!fileSplitterFetch.bDownOver) &cZl2ynPi  
{ a\B'Qe+  
breakWhile = false; -8Q}*Z  
break; !rTkH4!_  
} })umg8s  
} Vb,'VN%   
if(breakWhile) x(7Q5Uk\  
break; XsGc!  o  
C;I:?4  
8 k )i-&R  
//count++; #+8G`  
//if(count>4) i\dd  
// siteStop(); ']U<R=5T$  
} s<{) X$  
V/]o':  
&3f^]n!@  
System.err.println("文件下载结束!"); _sK{qQxvM=  
} $1Qcz,4B|  
catch(Exception e){e.printStackTrace ();} in7h^6?I  
} 2" u,f  
,t +sw4  
gX]ewbPDQ  
//获得文件长度 Gz:ell$  
public long getFileSize() Slv91c&md,  
{ ]([^(&2  
int nFileLength = -1; c0Yc~&RF  
try{ 9`td_qh  
URL url = new URL(siteInfoBean.getSSiteURL()); )Wy:I_F351  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ttA'RJ  
httpConnection.setRequestProperty("User-Agent","NetFox"); rUg|5EN^)d  
tE<'*o'  
(W |;gQ  
int responseCode=httpConnection.getResponseCode(); b6! 7 j  
if(responseCode>=400) J1Run0  
{ @_0tq{  
processErrorCode(responseCode); Hm'aD2k  
return -2; //-2 represent access is error +!mEP>  
} uj@d {AQ  
K(#O@Wmjq  
6 IRa$h>H  
String sHeader; @plh'f}  
M{g.x4M@W  
O>d [;Q  
for(int i=1;;i++) sAS[wcOQ  
{ RT<HiVr`  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (qzBy \\p  
//Utility.log(in.readLine()); hv*XuT/  
sHeader=httpConnection.getHeaderFieldKey(i); r7FpR!  
if(sHeader!=null) 3.6Gh|7  
{ JPM~tp?;<  
if(sHeader.equals("Content-Length")) nd }Z[)  
{ `L%<3/hF  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W<:x4gBa  
break; <"yL(s^u"  
} .'b| pd  
} U(2=fKK;  
else o~M=o:^nH  
break; sh*/wM  
} kS4YxtvB  
} r@EHn[w  
catch(IOException e){e.printStackTrace ();} x/ix%!8J  
catch(Exception e){e.printStackTrace ();} .Nk5W%7]=  
wz>[CXpi_  
#^{%jlmHxJ  
Utility.log(nFileLength); m qwJya  
P=.~LZZ]89  
LfN,aW  
return nFileLength; VniU:A  
} mrBK{@n  
)E m`kle  
u.Tknw-X  
//保存下载信息(文件指针位置) s8dP=_ `  
private void write_nPos() [qU`}S2  
{ Dt\rrN:v  
try{ CA5T3J@vAQ  
output = new DataOutputStream(new FileOutputStream(tmpFile)); a n0n8l  
output.writeInt(nStartPos.length); $'<FPbUtD}  
for(int i=0;i<nStartPos.length;i++) *U- :2uf  
{ T+oOlug  
// output.writeLong(nPos); \h?6/@3ob  
output.writeLong(fileSplitterFetch.nStartPos); @VQ<X4 Za  
output.writeLong(fileSplitterFetch.nEndPos); *T~b ox  
} 1024L;  
output.close(); "^)GnK +-  
} ^!z(IE'  
catch(IOException e){e.printStackTrace ();} MT6"b  
catch(Exception e){e.printStackTrace ();} -Jt36|O  
} Oh%p1$H  
b! r%4Ah  
qkqtPbQ 7  
//读取保存的下载信息(文件指针位置) [Sj"gLj  
private void read_nPos() A4(k<<xjE  
{ w c  
try{ b,X+*hRt  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "]|7%]  
int nCount = input.readInt(); 7A h   
nStartPos = new long[nCount]; p`EgMzVO,  
nEndPos = new long[nCount]; xQl}~G]!  
for(int i=0;i<nStartPos.length;i++) Bo\~PV[  
{ YFDOp *  
nStartPos = input.readLong();  DTa!vg  
nEndPos = input.readLong(); <s%Ft  
} >!Xj%RW  
input.close(); _-rC]iQJ55  
} 6s'n r7'0  
catch(IOException e){e.printStackTrace ();} YRMe<upo  
catch(Exception e){e.printStackTrace ();} j{D tjV8  
} m&s>Sn+  
)+ 'r-AF*  
7 IJn9b  
private void processErrorCode(int nErrorCode) 4sW'pH  
{ u%lUi2P2E  
System.err.println("Error Code : " + nErrorCode); kP'm$+1or  
} p:W{c/tV  
5nTcd@lX  
":q+"*fy  
//停止文件下载 T8&eaAoo  
public void siteStop() 97~>gFU77#  
{ TZGk[u^*  
bStop = true; jFip-=T{4  
for(int i=0;i<nStartPos.length;i++)  e<(6x[_  
fileSplitterFetch.splitterStop(); jGT|Xo>t  
hA;Ai:8  
%hlgLM  
} sVGQSJJ5  
} y0-UO+ ;  
//负责部分文件的抓取 }Q@~_3,UJ  
**FileSplitterFetch.java RAnF=1[v  
*/ 1;'-$K`}  
package NetFox; }h1eB~6M  
R.DUfU"gp  
\98N8p;,I  
import java.io.*; *?$M=tH  
import java.net.*; n`@dk_%yI  
&SNH1b#>E  
' sNiJ>  
public class FileSplitterFetch extends Thread { .Z#/%y3S  
,fqM>Q  
L62%s[  
String sURL; //File URL }"SqB{5e(  
long nStartPos; //File Snippet Start Position wX_~H*m?  
long nEndPos; //File Snippet End Position :H&G}T(#  
int nThreadID; //Thread's ID :KR KD  
boolean bDownOver = false; //Downing is over &W c$VDC  
boolean bStop = false; //Stop identical !|j|rYi-  
FileAccessI fileAccessI = null; //File Access interface 74N3wi5B  
s~bi#U;dF  
~I9o *cq  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p&5>j\uJ1&  
{ wOCAGEg  
this.sURL = sURL; gFrNk Uqp  
this.nStartPos = nStart; 0TSB<,9a[  
this.nEndPos = nEnd; #ti%hm  
nThreadID = id; !dU$1:7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t%J1(H  
} }}ic{931  
7!h> < sx  
IF-y/]  
public void run() TI t\  
{ HTz`$9  
while(nStartPos < nEndPos && !bStop) m(d|TwG{  
{ ez.a  
;<thEWH;Y  
&%GAPs%  
try{ iK+Vla`}  
URL url = new URL(sURL); Jp%5qBS^  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F3]VSI6^E,  
httpConnection.setRequestProperty("User-Agent","NetFox"); Lq1?Y  
String sProperty = "bytes="+nStartPos+"-"; MB $aN':  
httpConnection.setRequestProperty("RANGE",sProperty); <VQ)}HW;k  
Utility.log(sProperty); 1r_V$o$  
-%gEND-AP  
eO(U):C2  
InputStream input = httpConnection.getInputStream(); f$n5$hJlQ  
//logResponseHead(httpConnection); Pqw<nyC.  
("r:L<xe&  
Ir5|H|b<  
byte[] b = new byte[1024]; Jj\lF*B  
int nRead; q mv0LU  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $COjC!M  
{ T:Ee6I 3l  
nStartPos += fileAccessI.write(b,0,nRead); H0sTL#/L\  
//if(nThreadID == 1) E`V\/`5D  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^]'_Qbi]}  
} esQ$.L  
NdSuOkwwt  
m{?f,Q=u@  
Utility.log("Thread " + nThreadID + " is over!"); #.[eZ[  
bDownOver = true; KX 7 fgC  
//nPos = fileAccessI.write (b,0,nRead); 3fB]uq+eD%  
} ZTz07Jt  
catch(Exception e){e.printStackTrace ();} |FM*1Q[1  
} <Z<meB[g  
} a'/i/@h  
u%+k\/Scp.  
k4hk* 0Jq  
//打印回应的头信息 +xU({/  
public void logResponseHead(HttpURLConnection con) l"1D' Hk  
{ rUmP_  
for(int i=1;;i++) FMI1[|:;  
{ lw[c+F7  
String header=con.getHeaderFieldKey(i); FKu8R%9xn%  
if(header!=null) {jmy:e2  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3l41"5Fy&  
Utility.log(header+" : "+con.getHeaderField(header)); GGr82)E  
else 2 \}J*0  
break; 6]d]0TW_  
} qP<D9k>  
} SY[3O  
KR%WBvv   
Qni`k)4  
public void splitterStop() `>`b;A4  
{ |:JT+a1  
bStop = true; : ?BK A0E  
} S\< i`q  
^.\O)K {h  
M}#DX=NZc  
} uf9&o#  
QDV+(  
{?IbbT  
/* 9A} *  
**FileAccess.java h_S>Q  
*//文件访问(定位,写) i!e8-gVMP&  
package NetFox; -~lq <M  
import java.io.*; xk% 62W  
gCC7L(1  
htR.p7&Tn  
public class FileAccessI implements Serializable{ p/VVb%  
&0q pgl|  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )Hmf=eoc  
RandomAccessFile oSavedFile; vno/V#e$WX  
long nPos;  e]1Zey  
^N|8 B?Vg  
/OzoeI t  
public FileAccessI() throws IOException =3w;<1 ?'  
{ 9 %4:eTcp  
this("",0);  ;tZQ9#S  
} ^PezV5(  
PC<_1!M]  
@r/~Y]0Ye5  
public FileAccessI(String sName,long nPos) throws IOException qJrKt=CE  
{ $=N?[h&4  
oSavedFile = new RandomAccessFile(sName,"rw"); ceJi|`F  
this.nPos = nPos; ?X6}+  
oSavedFile.seek(nPos); ]4en |Aq  
} X(*O$B{ R  
l[ $bn!_ e  
& rab,I"  
public synchronized int write(byte[] b,int nStart,int nLen) &4S2fWx  
{ L}Y.xi  
int n = -1; jJNCNH*0  
try{ /}m*|cG/  
oSavedFile.write(b,nStart,nLen); o!":mJy  
n = nLen; y7fy9jQ 8.  
} SnmUh~`L~  
catch(IOException e) a~$Y;C_#<  
{ bC1G5`v_D  
e.printStackTrace (); !LwHKCj  
} ~Q]5g7k=&  
,Q7;(&x~  
)B0%"0?`8  
return n; >!xyA;  
} /0XMQy  
mA+:)?e5~  
()l3X.t,$  
} 3EICdC  
yW= +6@A4  
C$1W+(  
/* ]>VG}e~b  
**SiteInfoBean.java >- \bLr  
*/ ")STB8kQ  
package NetFox; @ gWd  
ngl +`|u  
Pa{  
public class SiteInfoBean { f(Of+>   
' 1gfXC  
Wq1 jTIQ  
private String sSiteURL; //Site's URL Pp tuXq%U  
private String sFilePath; //Saved File's Path ;: 2U}p^-  
private String sFileName; //Saved File's Name 1d<Uwb>  
private int nSplitter; //Count of Splited Downloading File aY>v  
R; c9)>8L  
'6 F-%  
public SiteInfoBean() =x\`yxsG  
{//nSplitter的缺省值为5 7*{f*({  
//default value of nSplitter is 5 QH9t |l  
this("","","",5); l\*9rs:!  
} @5S'5)4pB  
Q7$o&N{  
SscB&{f  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /D3{EjUE=  
{ zTw"5N  
sSiteURL= sURL; _V-KyK  
sFilePath = sPath; p/HDG ^T:u  
sFileName = sName; 2H)4}5H  
this.nSplitter = nSpiltter; k~"E h]38  
$ItjVc@U  
73D< wMgZF  
} 6`e7|ilh6  
=Nxkr0])!  
WQ.0}n}d  
public String getSSiteURL() 1*TbgxS~W  
{ WK>|IgK  
return sSiteURL; L>h8>JvQ  
} nTEN&8Y>R  
Gs,:$Im  
-SrZ^  
public void setSSiteURL(String value) F^ 75y?  
{ 0 Uropam  
sSiteURL = value; &xQM!f  
} Go)$LC0Mi  
kO}&Oi,?  
xV)[C )6  
public String getSFilePath() }oRBQP^&K  
{ dz] 5s  
return sFilePath; m0"K^p  
} TmQIpeych  
pa[/6(  
~P1~:AT  
public void setSFilePath(String value) P2-&Im`+  
{ {_O!mI*  
sFilePath = value; _5jT}I<k  
} E^axLp>(I  
8Y?M:^f~  
>1Z"5F7=  
public String getSFileName() ?BnU0R_r]  
{ (j&:  
return sFileName; \!-BR0+y;  
} N]A# ecm  
(jM0YtrD  
[>O!~  
public void setSFileName(String value) ?l0Qi  
{ YA4D?'  
sFileName = value; * j%x  
} '+PKGmRW  
`<C<[JP:o  
9{toPED  
public int getNSplitter() 6Yj{% G  
{ lM6pYYEq=  
return nSplitter; Gmz^vpQ]t  
} 0@ Y#P|QF  
l#'V SFm&  
to'7o8Z  
public void setNSplitter(int nCount) #Vq9 =Q2  
{ :aesG7=O  
nSplitter = nCount; E#B-JLMGl  
} ?l0eU@rwQ  
} Lnr9*dm6q  
Iux3f+H  
@Jzk2,rI  
/* +xFn~b/  
**Utility.java *; o%*:  
*/ 6p9fq3~7Y  
package NetFox; \#{PV\x:Nn  
*; Jb=  
/T w{JO#Q  
public class Utility { ANM#Kx+  
2%W;#oi?  
*GT=U(d  
public Utility() 8h=t%zMSb  
{ f!9i6  
4<y   
8QrpNSj4  
} j[G`p^ul  
}aZuCe_  
//线程睡眠 >HP `B2Q H  
public static void sleep(int nSecond) b(iF0U>&  
{ )kpEcMlR  
try{ j/O~8o&  
Thread.sleep(nSecond); i5VZ,E^E  
} c|&3e84U  
catch(Exception e) 7n8nJTU{4j  
{ ^3;B4tj[  
e.printStackTrace (); -*C WF|<G  
} {M]_]L{&7  
} D}_.D=)  
5R7x%3@L  
//日志 s2; ~FK#/  
public static void log(String sMsg) `JySuP2~/  
{ 36 "n7  
System.err.println(sMsg); cb}"giXQTB  
} (Xd8'-G$m  
NAGM3{\5v$  
|N.2iN:  
public static void log(int sMsg) _f1o!4ocx  
{ QL?_FwZL  
System.err.println(sMsg); z 6:Wh  
} 0HzqU31%l@  
} AkhG~L  
77P\:xc  
9LDv?kYr  
/* k9Pvh,_wp  
**TestMethod.java hbw(o  
*/ 5 ~Wg=u<6  
package NetFox; Z>hTL_|]a{  
;*A'2ymXUT  
#-/W?kD  
public class TestMethod { nBh+UT}  
E9:@H;Gc  
#[+# bw_6  
public TestMethod() ]I?.1X5d0  
{ ///xx/weblogic60b2_win.exe uO%0rKW  
try{ 2|nm> 4  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u,^CFws_  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OM86C  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y t(D  
fileFetch.start(); 9]4Q@%  
} 0U '"@A \  
catch(Exception e){e.printStackTrace ();} lSxb:$g  
Br1R++]  
T[oC='I+O  
} pSs*Z6c)@  
pgU [di  
V;M_Y$`Lh  
public static void main(String[] args) ]PXM;w  
{ GEBSUvM7  
new TestMethod(); UcRP/LR%C  
} ['d9sEv.  
} {v ?Q9  
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