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http断点续传简单实现(java)

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/* KSLyU1W  
**SiteFileFetch.java vK|d P3  
*/ >V NMQ  
package NetFox; xGz$M@f  
import java.io.*; R,tR{| 8  
import java.net.*; wWwY .}j  
3C.bzw^  
P_w+p"@m  
public class SiteFileFetch extends Thread { w2Pkw'a{  
-[ F<u  
N>VA`+aFR  
SiteInfoBean siteInfoBean = null; //文件信息Bean 3EAu#c@q"  
long[] nStartPos; //开始位置 `57ffQR9  
long[] nEndPos; //结束位置 G:f]z;Xdp  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 o-/Xa[yC  
long nFileLength; //文件长度 9!PJLI=D  
boolean bFirst = true; //是否第一次取文件 "Sl";.   
boolean bStop = false; //停止标志 3 bGpK9M~  
File tmpFile; //文件下载的临时信息 BjJ+~R  
DataOutputStream output; //输出到文件的输出流 cp[k[7XGD  
6N6d[t"  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) t + Fm?  
public SiteFileFetch(SiteInfoBean bean) throws IOException xez~Yw2  
{ :)bm+xWFF  
siteInfoBean = bean; is`le}$^y  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 2T iUo(MK  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); =eYrz@,  
if(tmpFile.exists ()) aA=qel  
{ 'kPShZS$b  
bFirst = false; ?/NxZ\  
read_nPos(); ?-J\~AXL  
} w,D(zk$   
else ;Cm%<vW4!  
{ 7LKNEll  
nStartPos = new long[bean.getNSplitter()]; y~;Kf0~  
nEndPos = new long[bean.getNSplitter()]; zZseK  
} sJ!AI n<  
]M>mwnt+  
N3i}>Q)B  
f5^[`b3H  
} H$WuT;cTE  
7 zK%CJ  
l[.RnM[v  
public void run() 6wfCC,2  
{ +.5 /4?  
//获得文件长度 |no '^  
//分割文件 G[)QGZ}8b  
//实例FileSplitterFetch HLa|yc B%  
//启动FileSplitterFetch线程 Id|38   
//等待子线程返回 1+v)#Wj  
try{ 7>v1w:cC]  
if(bFirst) -bduB@#2d  
{ r6QNs1f~.  
nFileLength = getFileSize(); #%Uk}5;-  
if(nFileLength == -1) _G,`s7Q,w  
{ MHk\y2`/;  
System.err.println("File Length is not known!"); 3\G&fb|?}R  
} T/UhZ4(V  
else if(nFileLength == -2) r( :"BQ  
{ A F>!:  
System.err.println("File is not access!"); mRFcZ.7  
} 5 J61PuH   
else Sr/"'w;  
{ !ai, \  
for(int i=0;i<nStartPos.length;i++) /c8F]fkZ=  
{ zuwCN.  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); SX$v&L<  
} p.n+m[  
for(int i=0;i<nEndPos.length-1;i++) {w1sv=$+  
{ j[v<xo  
nEndPos = nStartPos[i+1]; Zw` Xg@;xP  
} fXEF]C  
nEndPos[nEndPos.length-1] = nFileLength; s -~Tf|  
} -!k"*P  
} vn9_tL&  
hj4Kv  
u+~Ta  
//启动子线程 N{ @B@]  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D<]z.33  
for(int i=0;i<nStartPos.length;i++) =i4Ds  
{ _ ^r KOd  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {YT!vD9.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &ScADmZP^d  
nStartPos,nEndPos,i); oyiEOC  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MyXgp>?~T  
fileSplitterFetch.start(); X~T"n<:a>  
} Yw vX SA  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C2<!.l  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '!I^Lfz-Z  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m\)z& hv<r  
nEndPos = " + nFileLength); D4?5 %s  
// fileSplitterFetch[nPos.length-1].start(); "}Of f  
CD;C z*c  
d;daYjOm  
//等待子线程结束 T&   
//int count = 0; t-)C0<  
//是否结束while循环 l}A8  
boolean breakWhile = false; K1AI:$H  
G>qzAgA  
qCi6kEr  
while(!bStop) %(79;#2`  
{ prV:Kq;O  
write_nPos(); za `  
Utility.sleep(500); Es/\/vF7]D  
breakWhile = true; DJ2EV^D+P  
VPx"l5\  
M}kt q)  
for(int i=0;i<nStartPos.length;i++) Fc% @  
{ > SU2Jw  
if(!fileSplitterFetch.bDownOver) : n 4?  
{ C0eP/d  
breakWhile = false; KWq7M8mq  
break; K3Zc>QL{  
} hiZE8?0+~N  
} . T6fPEb  
if(breakWhile) q$(@  
break; 5*l~7R  
(,#Rj$W  
/f@VRME  
//count++; nw){}g  
//if(count>4) l*T> 9yC  
// siteStop(); </ 3 Shq  
} ]([:"j  
4mq+{c0  
rLw3\>y  
System.err.println("文件下载结束!"); n7>CK?25  
} j'Z}; 3y  
catch(Exception e){e.printStackTrace ();} [#S}L(  
} H|T!}M>  
vtM!?#  
@-|{qP=Dy  
//获得文件长度 R}'kF63u*  
public long getFileSize() 6Lk<VpAa  
{ [XK Ke  
int nFileLength = -1; TR/'L!EE  
try{ {%.FIw k  
URL url = new URL(siteInfoBean.getSSiteURL()); f0]8/)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c%9wI*l  
httpConnection.setRequestProperty("User-Agent","NetFox"); o7' cC?u  
!*_5 B'  
v<c~ '?YzO  
int responseCode=httpConnection.getResponseCode(); Bt[OGa(q  
if(responseCode>=400) }>Gnp c  
{ P~$FgAV  
processErrorCode(responseCode); :oh(M|;/2  
return -2; //-2 represent access is error u4*7 n-(  
} BQq,,i8H  
bU9B2'%E  
t2d _XQOK  
String sHeader; /^v?Q9=Y  
RLBjl%Q>  
)xYv$6=  
for(int i=1;;i++) m22M[L(q  
{ WD c2Qt  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *&]x-p1m  
//Utility.log(in.readLine()); bI/d(Q%#<  
sHeader=httpConnection.getHeaderFieldKey(i); (,<&H;,8  
if(sHeader!=null) chv0\k"'  
{ Z".mEF-b  
if(sHeader.equals("Content-Length")) Q|/uL`_ni  
{ |y=;#A  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W!|A3V35\:  
break; pcwkO  
} R L&z\S  
} +Gv{Apd"  
else 2gLa4B-  
break; &(a#I]`9M  
} a'=C/ s+  
} gRA}sF  
catch(IOException e){e.printStackTrace ();} Blv!%es  
catch(Exception e){e.printStackTrace ();} Z |wM  
^c",!Lp}{  
A??(}F L  
Utility.log(nFileLength); ma@3BiM  
#Bq.'?c'~  
.zxP,]"l  
return nFileLength; P[{qp8(g  
} }? j>V  
2(~Y ^_  
)f(.{M  
//保存下载信息(文件指针位置) DtkY;Yl  
private void write_nPos() 3~ITvH,`s  
{ JQ|qg\[  
try{ %H OMX{~}#  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Du@?j7&l=$  
output.writeInt(nStartPos.length); :l<)p;\  
for(int i=0;i<nStartPos.length;i++) *opf~B_e  
{ ` QC  
// output.writeLong(nPos); Qx{k_ye`  
output.writeLong(fileSplitterFetch.nStartPos); $%~-p[)<(P  
output.writeLong(fileSplitterFetch.nEndPos); 0\3mS{s  
} %Ci`O hT  
output.close(); Z^?1MJ:`  
} 0 ?kaXD  
catch(IOException e){e.printStackTrace ();} wc z|Zy  
catch(Exception e){e.printStackTrace ();} h&Thq52R  
} |tL57Wu93  
=\CJsS.  
H}G=%j0  
//读取保存的下载信息(文件指针位置) $B6CLWB  
private void read_nPos() @pq#?  
{ .Y B}w  
try{ HsrIw  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O%RkU?ME  
int nCount = input.readInt(); jSa9UD  
nStartPos = new long[nCount]; Q|40 8EM  
nEndPos = new long[nCount]; X"QIH|qx-  
for(int i=0;i<nStartPos.length;i++) fh~"A`d  
{ Fe8JsB-  
nStartPos = input.readLong(); EX^}#|e*h  
nEndPos = input.readLong(); ];BGJ5^j  
} z"/Mva3|  
input.close(); 4u} "ng   
} #sl_ BC9  
catch(IOException e){e.printStackTrace ();} 8vFt<k}G  
catch(Exception e){e.printStackTrace ();} m# #( uSh  
} 0ox 8_l  
;{1J{-EA  
,nn5LQ|l.j  
private void processErrorCode(int nErrorCode) `m2e *  
{ 52+;j[ ]/O  
System.err.println("Error Code : " + nErrorCode); (eX9O4  
} v=!Ap ; 2L  
WT(inf[  
&0B< iO<f  
//停止文件下载 d&S4`\g?8  
public void siteStop() /*g9drwaa  
{ c2M-/ x-:  
bStop = true; aq-`Bar  
for(int i=0;i<nStartPos.length;i++) Hg8n`a;R  
fileSplitterFetch.splitterStop(); F O"8B  
zh5'oE&[yC  
dre@V(\;hQ  
} z@!zQ Vp  
} m)G=4kK52-  
//负责部分文件的抓取 QmQsNcF~z  
**FileSplitterFetch.java f8]Qn8  
*/ TBq;#+1W  
package NetFox; |n9~2R   
;8WgbR)ZLU  
qyXx`'e  
import java.io.*; 7U=|>)Q0s  
import java.net.*; ^qNh)?V?]I  
w k1O*_76  
BR8W8nRb  
public class FileSplitterFetch extends Thread { $HjKELoJ<  
mHTZ:84  
4%l @   
String sURL; //File URL emZ^d/A  
long nStartPos; //File Snippet Start Position rNzsc|a:  
long nEndPos; //File Snippet End Position 1rhsmcE  
int nThreadID; //Thread's ID /4 zO  
boolean bDownOver = false; //Downing is over j.C)KwelBS  
boolean bStop = false; //Stop identical @V$,H/v:  
FileAccessI fileAccessI = null; //File Access interface e&&;"^@-  
.ZSGnbJ  
cG%ttfq\  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V,,/}f '  
{ )9_jr(s  
this.sURL = sURL; &cj/8A5-  
this.nStartPos = nStart; _n9+(X3  
this.nEndPos = nEnd; KX*Hev'K  
nThreadID = id; $`q8-+{  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a }6Fj&hj  
} KM$5ZbCF:  
NwQexYm1_  
z-(#Mlq:!  
public void run() 1_JxDT,=>  
{ wg6![Uh  
while(nStartPos < nEndPos && !bStop) .0x+b-x  
{ u rGk_.f  
Zf~ [4Eeb  
z`gdE0@;d3  
try{ jYwv+EXg  
URL url = new URL(sURL); ^{<x*/nK  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4Q0@\dR9  
httpConnection.setRequestProperty("User-Agent","NetFox"); X|.M9zIx  
String sProperty = "bytes="+nStartPos+"-"; @g|E b}t  
httpConnection.setRequestProperty("RANGE",sProperty); qw A N=3@  
Utility.log(sProperty); wn*z*  
F?j;3@z[A  
4m++>q  
InputStream input = httpConnection.getInputStream(); r4Ygy/%  
//logResponseHead(httpConnection); ZdQm& ?  
y^; =+Z  
uA;3R\6?  
byte[] b = new byte[1024]; ]+\@_1<ZI  
int nRead; /BWJ)6#H  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dZ!Wj7K)  
{ `!MyOI`qS  
nStartPos += fileAccessI.write(b,0,nRead); mT57NP  
//if(nThreadID == 1) 6T6 S9A*nT  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hjiU{@q  
} !Ju?REH   
2A3;#v  
\Cx) ~bq<  
Utility.log("Thread " + nThreadID + " is over!"); <YbOO{  
bDownOver = true; $)| l#'r  
//nPos = fileAccessI.write (b,0,nRead); Zl]Zy}p*+  
} w>I>9O}(`  
catch(Exception e){e.printStackTrace ();} 7^k`:Z  
} +Ux)m4}j  
} NLDmZra  
=J.)xDx*  
oRM EC7!A0  
//打印回应的头信息 od>DSn3T  
public void logResponseHead(HttpURLConnection con) y:!MWZ  
{ x&3!z[m@@  
for(int i=1;;i++) 4QWDuLu  
{  9H*$3  
String header=con.getHeaderFieldKey(i); ~CRr)(M  
if(header!=null) s~$kzEtjjU  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _>HX Q6Hw  
Utility.log(header+" : "+con.getHeaderField(header)); UTQ$sg|7p  
else }~lF Rf  
break; OVO0Emv  
} [KkLpZG  
} jIMaP T  
+MC>?rr_u  
s-r$%9o5  
public void splitterStop() e,Xvt5  
{ uR"srn;^  
bStop = true; puS'9Lpp  
} ]I"oS?  
p#.B Fy  
XgKtg-,  
} 9bjjo;A  
@f0~a  
CAY^ `K!  
/* c1wM"  
**FileAccess.java Kzxzz6R?  
*//文件访问(定位,写) ".| 9h  
package NetFox; >]"5K<-1  
import java.io.*;  ,[ +  
~az 6n)  
sSOI5W3A  
public class FileAccessI implements Serializable{ ZZTPAmIr  
_,b%t1v  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7dX1.}M<(  
RandomAccessFile oSavedFile; %iIryv;  
long nPos; _jef{j  
A <iF37.  
e =& abu  
public FileAccessI() throws IOException ld94ek  
{ 7"=  
this("",0); ,oDZ:";  
} g'Ft5fQ"o/  
j._9;HifZ  
ltt%X].[  
public FileAccessI(String sName,long nPos) throws IOException >82Q!HaH  
{ E?&dZR  
oSavedFile = new RandomAccessFile(sName,"rw"); 'q1)W'  
this.nPos = nPos; sCaw"{5qc  
oSavedFile.seek(nPos); /exV6D r  
} u7@|fND 7  
%'`Dd  
'jcDfv(v<  
public synchronized int write(byte[] b,int nStart,int nLen) iAf, :g  
{ qsFA~{o.  
int n = -1; oypq3V=5  
try{ XPzwT2_E  
oSavedFile.write(b,nStart,nLen); =,-80WNsX  
n = nLen; 6fPuTQ}fY>  
} ,e>C)wq;  
catch(IOException e) M#})  
{ /'E+(Y&:J  
e.printStackTrace (); $$ {ebt  
} %kNkDI  
*%ZfE,bu8<  
Gyy:.]>&  
return n; 8NeP7.U<w  
} 65ijzZL;  
Mim 9C]h(  
e@p` -;<  
} hr@KWE`  
A3&8@/6,  
-+|0LXo  
/* B/E1nBobC  
**SiteInfoBean.java D8h ?s  
*/ }<FBcc(n  
package NetFox; Qo?"hgjlqm  
=DE5 Wq19  
8[f]9P/i  
public class SiteInfoBean { xQ1&j,R]  
@)VJ,Ql$Y  
O:r<es1  
private String sSiteURL; //Site's URL CJjma=XH  
private String sFilePath; //Saved File's Path / c/!13|  
private String sFileName; //Saved File's Name H|F>BjXn5  
private int nSplitter; //Count of Splited Downloading File \R&`bAdk  
K]@6&H-b|  
2|EH Ny!  
public SiteInfoBean() BAm H2"  
{//nSplitter的缺省值为5 6$SsdT|8B  
//default value of nSplitter is 5 D8`,PXtV  
this("","","",5); zfi{SO l  
} M0c"wi@S_  
5/:Zj,41{  
ICq;jfML  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PKdM-R'Z  
{ o [ar.+[  
sSiteURL= sURL; \C}tK,79  
sFilePath = sPath; :+]6SC0ql  
sFileName = sName; I$qL=  
this.nSplitter = nSpiltter; a<!g*UVL0M  
F8b*Mt}p  
`mw@"  
} W@"M/<r@/  
yuFuYo&[?v  
?ZlwRjB\  
public String getSSiteURL() P; hjr;  
{ 3m7$$ N|  
return sSiteURL; _sZ/tU@_-K  
} F1Egcx/$V  
t47 f$gq  
34JkB+#a  
public void setSSiteURL(String value) c)@M7UK[  
{ 4CX*  
sSiteURL = value; S)g5Tu)  
} L=Dx$#|  
MrOW&7  
.&r] ?O  
public String getSFilePath() ]3 0 7 .  
{ X:8=jHkz  
return sFilePath; J_rCo4}  
} EF)kYz!@  
c~R ElL  
\FVR'A1  
public void setSFilePath(String value) =\X<UA}  
{ oH6(Lq'q  
sFilePath = value; n6Q 3X  
} cY\-e?`=4  
[`ttNW(_  
,Hys9I  
public String getSFileName() ~Gwn||g78  
{ gvA&F |4  
return sFileName; 8l!S<RA  
} L>@0Nne7  
Fdc bmQ  
 J|6aa  
public void setSFileName(String value) 6_zL#7E'  
{ `;cKN)Xk  
sFileName = value; Qt>yRt  
} 8VMq>-  
.V/TVz!b  
1f[!=p  
public int getNSplitter() 8{?Oi'-|0  
{ D*D83z OzN  
return nSplitter; &rw|fF|]  
} C:4h  
Zls4@/\Q  
<PV @JJ"  
public void setNSplitter(int nCount) 3%<ia$  
{ BvX!n"QIb  
nSplitter = nCount; gN mp'Lm  
} zT_{M qY  
} -pqShDar|  
'Iu$4xo`[  
OkzfQ hC}  
/* cE]tvL:g  
**Utility.java #exE ~@fy-  
*/ ;2dhue  
package NetFox; 7!MW`L/`  
HCHC~FNd  
00b )Bg  
public class Utility { &,)9cV /  
!(SaE'  
7z%zXDe~T[  
public Utility() `]tXQqD  
{ AFMAgf{bD  
,C=Fgxw(  
-QZped;?*  
} 4s"8e]q=  
3j.f3~"  
//线程睡眠 h ?p^DPo  
public static void sleep(int nSecond) (#Y2H  
{ R_@yj]%H=  
try{ (5G^"Srw  
Thread.sleep(nSecond); @9vz%1B<l  
} e j!C^  
catch(Exception e) 1Ete;r%5=  
{ Pi+,y  
e.printStackTrace (); "F%cn@l  
} vRT1tOQ$  
} e?Cbl'  
)C|>M'g@v  
//日志 evszfCH'J  
public static void log(String sMsg) +(|T\%$DT  
{ nH T2M{R  
System.err.println(sMsg); vkBngsS  
} kTC6fNj[  
dAAE2}e  
W"wP%  
public static void log(int sMsg) X0U{9zP  
{ cm7aL%D$c  
System.err.println(sMsg); EzG7RjW  
} #~p1\['|M  
} `+* Mr  
vn,L),"=  
TSuHY0. cp  
/* 'iL['4~.  
**TestMethod.java <[a9"G 7  
*/ &p4q# p7,  
package NetFox; z),l&7  
] YQ*mvI]  
:_H$*Q=1  
public class TestMethod { GD*6tk;5/  
fMLm_5(H  
Yq;S%.  
public TestMethod() },[j+wx  
{ ///xx/weblogic60b2_win.exe =VY[m-q5  
try{ u4.-AY {  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pV>/ "K  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;o8cfD.z  
SiteFileFetch fileFetch = new SiteFileFetch(bean); y f+/Kj< a  
fileFetch.start(); ]Fj z+CGg  
} 9"<)DS  
catch(Exception e){e.printStackTrace ();} <'B`b  
C{Npipd}v  
tk, H vE  
} 0Y"==g+ >f  
pK$^@~DE  
teM&[U  
public static void main(String[] args) cQ+V 4cW Z  
{ WJJ!No P  
new TestMethod(); !_V*VD  
} +o_`k!  
} ZC0F:=/K  
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