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http断点续传简单实现(java)

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/* ?g@X+!RB  
**SiteFileFetch.java if\`M'3Xx  
*/ XA.1Y)  
package NetFox; OR+py.vK  
import java.io.*; 8$iHd  
import java.net.*; *nHMQ/uf  
ObreDv^,  
".( G,TW  
public class SiteFileFetch extends Thread { 3N2d@R  
+tg${3ti_  
ta x:9j|~  
SiteInfoBean siteInfoBean = null; //文件信息Bean L %ifl:K  
long[] nStartPos; //开始位置 q?]KZ_a  
long[] nEndPos; //结束位置 ]E DC s?,  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 b~YIaD[Z  
long nFileLength; //文件长度 368 g> /#'  
boolean bFirst = true; //是否第一次取文件 *a{WJbau]  
boolean bStop = false; //停止标志 " L,9.b  
File tmpFile; //文件下载的临时信息 L@Qvj-5e  
DataOutputStream output; //输出到文件的输出流  fWs*u[S  
seP h%Sa_  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) %i?v)EW  
public SiteFileFetch(SiteInfoBean bean) throws IOException {KEmGHC4R  
{ =kK%,Mr  
siteInfoBean = bean; pbWjTI$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); U^)`_\/;?  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); :+ 1Wmg  
if(tmpFile.exists ()) `@:TS)6X0  
{ A>FWvlLw'm  
bFirst = false; plJUQk  
read_nPos(); 7xG~4N<)]  
} *1_Ef).  
else %AWc`D  
{ 4HGS  
nStartPos = new long[bean.getNSplitter()]; _nX8f &  
nEndPos = new long[bean.getNSplitter()]; :c8d([)$  
} R)isWw4  
&Ll&A@yU  
`YMd0*  
@^g~F&Ta  
} 2vsV :LS.  
*{Z=)k%  
=1 S%E  
public void run() x_C0=Q|K3  
{ WNKP';(a@G  
//获得文件长度 aS\$@41"  
//分割文件 p:0X3?IG3  
//实例FileSplitterFetch \W= qqE]  
//启动FileSplitterFetch线程 KU]o=\ak%  
//等待子线程返回 0O*kC43E_  
try{ %9S0!h\  
if(bFirst) AR$SQ_4  
{ m_`%#$s}  
nFileLength = getFileSize(); 0 ?gHRdU"  
if(nFileLength == -1) BIe:7cR%  
{ r=54@`O!  
System.err.println("File Length is not known!"); Sw5-^2x0'  
} j4]3}t0q  
else if(nFileLength == -2) h@(+(fVHrp  
{ m&'!^{av  
System.err.println("File is not access!"); S3E5^n\\  
} _u~0t`f~  
else Z{yH:{Vk  
{ @' ;.$  
for(int i=0;i<nStartPos.length;i++) QgQ$>  
{ 4udj"-V  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =]/<Kd}A.  
} ={N1j<%fh  
for(int i=0;i<nEndPos.length-1;i++) #Q*V9kvU/H  
{ v=cQ`nou  
nEndPos = nStartPos[i+1]; ,w BfGpVb  
} ZrZDyXL  
nEndPos[nEndPos.length-1] = nFileLength; WjM7s]ZRv  
} j:/Z_v'  
} R:R<Xt N`5  
CA5`uh  
&;L=f;   
//启动子线程 .uxM&|0H  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t4/ye>P &  
for(int i=0;i<nStartPos.length;i++) _nxH;Za  
{ uN>5Eh&=Pf  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c-n/E. E  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0\B{~1(^  
nStartPos,nEndPos,i); yO!M$aOn/  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w-LENdw  
fileSplitterFetch.start(); $gD8[NAIx=  
} ; D/6e6  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L G5_\sY!  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nb<oo:^  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kw]?/s`  
nEndPos = " + nFileLength); y)CvlI  
// fileSplitterFetch[nPos.length-1].start(); u'>94Gm}  
7Zd g314  
U,;796h  
//等待子线程结束 @|Yn~PwKs  
//int count = 0; ctLNzJes%  
//是否结束while循环  ms&1P  
boolean breakWhile = false; q^Oj/ws  
5Pn.c!  
|('o g*$  
while(!bStop) 2.b,8wT/  
{ t H.L_< N  
write_nPos(); ::$W .!Uv  
Utility.sleep(500); .SER,],P  
breakWhile = true; g3>>gu#0DC  
3Ke6lV)uq  
+qC [X~\  
for(int i=0;i<nStartPos.length;i++) L~Peerby  
{ `?3f76}h  
if(!fileSplitterFetch.bDownOver) [xr^t1  
{ /W BmR R  
breakWhile = false; f pq|mY  
break; K.Y`/<  
} cGgfCF^`  
} aK@ Y) Ju'  
if(breakWhile) W.jXO"pN  
break; % ym};7'&b  
111A e *U  
H)7v$A,5%  
//count++; V@#oQi*  
//if(count>4) TPk?MeVy%W  
// siteStop(); %\T,=9tD\  
} m x |V)  
3c3;8h$k  
`Y4Kw  
System.err.println("文件下载结束!"); B#jnM~fJz  
} oYZ  4F  
catch(Exception e){e.printStackTrace ();} 3J &R os  
} v>B412l  
nf 8V:y4  
1Ng.Ukb  
//获得文件长度 u*)/e9C  
public long getFileSize() W wPzm?30  
{ 2WFZ6  
int nFileLength = -1; 3rH}/`d4  
try{ L4m Vk  
URL url = new URL(siteInfoBean.getSSiteURL()); X%IqZ{ {  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hDJG.,r  
httpConnection.setRequestProperty("User-Agent","NetFox"); n*wQgC'vw  
{&IB[Y6  
e! *] y&W  
int responseCode=httpConnection.getResponseCode(); eb\SpdM6  
if(responseCode>=400) {jB> ]7  
{ %0C [v7\  
processErrorCode(responseCode); ?`Yu~a{  
return -2; //-2 represent access is error ]wU/yc)e  
} -|#{V.G3'  
m.m6.  
1\m,8i+gU  
String sHeader; c.IUqin  
6-_g1vq  
JVX)>2&$  
for(int i=1;;i++) u NyN[U  
{ d/Q#Z  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H@ 1'El\9  
//Utility.log(in.readLine()); 2lpPN[~d  
sHeader=httpConnection.getHeaderFieldKey(i); 5 :IDl1f5  
if(sHeader!=null) >^jBE''  
{ N<rq}^qo  
if(sHeader.equals("Content-Length")) uS`}  
{ < bC'.m  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); . f ja;aG  
break; .t1:;H b  
} IAH"vHM  
} Ur xiaE  
else :6nD"5(  
break; \s*UUODWK  
} 8)1q,[:M  
} , yltt+ e  
catch(IOException e){e.printStackTrace ();} (`dz3 7@*  
catch(Exception e){e.printStackTrace ();} UF!qp  
Z|n|gxe  
tVAo o-%  
Utility.log(nFileLength); $M)i]ekm  
Q&]|W Xv  
;Yee0O!d4  
return nFileLength; ]M*`Y[5"  
} $\NqD:fgb  
/(JG\Ut  
&RZO\ZT  
//保存下载信息(文件指针位置) `#ruZM066  
private void write_nPos() xA Ez1  
{ 4}m9,  
try{ IrL%0&*hS  
output = new DataOutputStream(new FileOutputStream(tmpFile));  b M1\z  
output.writeInt(nStartPos.length); v=@y7P1  
for(int i=0;i<nStartPos.length;i++) AaYH(2m-  
{ k4V3.i!E  
// output.writeLong(nPos); \:J=tAC  
output.writeLong(fileSplitterFetch.nStartPos); rgVRF44X{  
output.writeLong(fileSplitterFetch.nEndPos); OWewV@VXR  
} 3Qe|'E,U  
output.close(); @G2# Z  
} Np+PUu>  
catch(IOException e){e.printStackTrace ();} t\ oud{Cv  
catch(Exception e){e.printStackTrace ();} 1jd{AqHl  
} \+V"JIStUj  
>O\+9T@  
%N-aLw\  
//读取保存的下载信息(文件指针位置) x\G%  
private void read_nPos() I #1~CbR  
{ I/njyV)H  
try{ $~6MR_Yq  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vT Eq T  
int nCount = input.readInt(); D:Q#%wJ  
nStartPos = new long[nCount]; [bHm-X]  
nEndPos = new long[nCount]; ,5$G0  
for(int i=0;i<nStartPos.length;i++) $"vz>SuB  
{ 1+Gq<]@G  
nStartPos = input.readLong(); |` :cB  
nEndPos = input.readLong(); qhY+<S9  
} E'a OHSAg  
input.close(); _+B y=B.'  
} *gwaW!=  
catch(IOException e){e.printStackTrace ();} gw"cXny  
catch(Exception e){e.printStackTrace ();} :o8`2Z*g  
} eP]y\S*P  
p*c(dkOe8  
"BSY1?k{  
private void processErrorCode(int nErrorCode) 8S#$'2sT  
{ O z0-cM8t  
System.err.println("Error Code : " + nErrorCode); z)C}}NH*!@  
} "j_iq"J  
DYf2V6'  
iXm&\.%  
//停止文件下载 v<v;ZR)  
public void siteStop() mvjx &+q  
{ /=;,lC  
bStop = true; .rk5u4yK  
for(int i=0;i<nStartPos.length;i++) 4nm.ea|  
fileSplitterFetch.splitterStop(); ~JT2el2W7p  
gg#9I(pX  
hhPQ.{]>  
} g*b`o87PI  
} 8j>V?'Szk  
//负责部分文件的抓取 z~h?"'  
**FileSplitterFetch.java #tKks:eL  
*/ ,Sgo_bC/|  
package NetFox; 7#C$}1XJ1  
;t+p2i  
t, %m-dU  
import java.io.*; TQO|C?  
import java.net.*; 68?&`/t  
m~Pk ]~j  
4|_xz; i  
public class FileSplitterFetch extends Thread { lx2#C9L_  
4C?{p%3c  
Mk#r_:[BS  
String sURL; //File URL &C MBTY#u  
long nStartPos; //File Snippet Start Position }'Ap@4  
long nEndPos; //File Snippet End Position :.AC%'S  
int nThreadID; //Thread's ID z+.G>0M  
boolean bDownOver = false; //Downing is over C2R"96M7q  
boolean bStop = false; //Stop identical kKF=%J?X  
FileAccessI fileAccessI = null; //File Access interface |[n\'Xy;{  
SHYekX  
:i>LESJq  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m)6 6g]F+  
{ @VP/kut  
this.sURL = sURL; ti GH#~?  
this.nStartPos = nStart; #8t=vb3  
this.nEndPos = nEnd; a"P & 9c  
nThreadID = id; 'E#L6,&  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KLM6#6`  
} BsXF'x<U*  
H$ nzyooh  
7|=SZ+g  
public void run() HAE$Np|>a  
{ EUt2 S_2P  
while(nStartPos < nEndPos && !bStop) S".|j$  
{ D A=LR  
JUw|nUnl?  
+>1Yp">?  
try{ ,+BFpN'  
URL url = new URL(sURL); VB/75xK_  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EIzTbW{p  
httpConnection.setRequestProperty("User-Agent","NetFox"); &O+S [~  
String sProperty = "bytes="+nStartPos+"-"; ){/n7*#Th%  
httpConnection.setRequestProperty("RANGE",sProperty); dj084q7  
Utility.log(sProperty); 6$PQ$  
(~\HizSl  
w@WtW8 p^  
InputStream input = httpConnection.getInputStream(); |o eg'T  
//logResponseHead(httpConnection); SgQmR#5  
-GL.8" c[  
nUq@`G  
byte[] b = new byte[1024]; a$uD oi  
int nRead; `Q+O#l?  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) # .&t'"u  
{ *@lVesC2  
nStartPos += fileAccessI.write(b,0,nRead); lnl>!z  
//if(nThreadID == 1) Q.4+"JoG  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y"5FK  
} p&(z'd  
 [Ketg  
#?M[Q:  
Utility.log("Thread " + nThreadID + " is over!"); N["M "s(N  
bDownOver = true; QWm g#2'  
//nPos = fileAccessI.write (b,0,nRead); 'u PI~l`g  
} r^s$U,e#~  
catch(Exception e){e.printStackTrace ();} |&S^L}V.C  
} V:D?i#%,z  
} Xa}y.qH  
FzsW^u+  
bneP>Bd  
//打印回应的头信息 Ki :98a$  
public void logResponseHead(HttpURLConnection con) F9_X^#%L  
{ '&AeOn  
for(int i=1;;i++) hNcEBSQ  
{ vKbGG   
String header=con.getHeaderFieldKey(i); s?sr0HZ  
if(header!=null) 's8LrO(=  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EffU-=?%!  
Utility.log(header+" : "+con.getHeaderField(header)); jfR!M07|  
else gU@.IOg  
break; XC[AJ!q`  
} NUY sQO)  
} Ip,0C8T`Q  
.GDY J9vi  
\$8p8MP<&D  
public void splitterStop() I} ]s(  
{ "Bn]-o|r  
bStop = true; n QOLR? %  
} nza^<DlS  
b\"2O4K,)  
ra\2BS)X  
} }PzYt~Z`@  
SI l<\  
{<^PYN>`  
/* (@*#Pn|A  
**FileAccess.java j98>Jr\  
*//文件访问(定位,写) }~Y#N  
package NetFox; aQfrDM<*XS  
import java.io.*; CY8=prC  
@|o^]-,  
_i&awm/U  
public class FileAccessI implements Serializable{ D)LqkfJ}z^  
}"9jCxXL  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =kWm9W<^  
RandomAccessFile oSavedFile; !bD`2m[Q  
long nPos; A?OaP  
YR/rN,  
-RnQ8Iu o  
public FileAccessI() throws IOException KbF,jm5  
{ E2{SKIUm  
this("",0); faaFmEC  
} GCPSe A~cx  
A ptzBs/  
gnSb)!i>z  
public FileAccessI(String sName,long nPos) throws IOException du4Q^-repC  
{ {oN7I'>  
oSavedFile = new RandomAccessFile(sName,"rw"); sHulaX{  
this.nPos = nPos; O>`DR0  
oSavedFile.seek(nPos);  snyg  
} 2s@<k1EdPl  
0dgp<  
:X;' 37o#q  
public synchronized int write(byte[] b,int nStart,int nLen) vL7 JzSU_  
{ J Covk1  
int n = -1; ,0=:06l  
try{ .DSmy\FI5  
oSavedFile.write(b,nStart,nLen); J@c)SK%2h  
n = nLen; $fA%_T_P'P  
} EBN'u&zX  
catch(IOException e) @t6B\ ?4'T  
{ 7Z/KXc[b  
e.printStackTrace (); hqVFb.6[  
} ;'r} D!8w/  
D?3^>h  
,9W|$2=F  
return n; .W<yiB}^  
} -&* 4~  
C&m[/PJ~l  
257pO9]  
} h$EH|9HAb  
}Q?, O  
\ueo^p]_?  
/* ch}t++`l]  
**SiteInfoBean.java [' ~B &  
*/ B#_<?  
package NetFox; 2R2ws.}  
 ((}T^  
3U0>Y%m|,  
public class SiteInfoBean { i5sNCt  
~e5hfZv|w  
1>1&NQ#}  
private String sSiteURL; //Site's URL Uv~r]P)  
private String sFilePath; //Saved File's Path 9"3 7va  
private String sFileName; //Saved File's Name E {$Jk]c  
private int nSplitter; //Count of Splited Downloading File =G%k|  
T\VKNEBo  
WKib$(%f6  
public SiteInfoBean() F/FUKXxx  
{//nSplitter的缺省值为5 v"VpE`z1#  
//default value of nSplitter is 5 ;N4A9/)  
this("","","",5); [%M=nJ{8  
} X\:;A{  
59;p|  
G=R`O1-3  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $[L~X M  
{ ,iKL 68  
sSiteURL= sURL; !e5!8z  
sFilePath = sPath; xx`xDD  
sFileName = sName; #1-,s.)  
this.nSplitter = nSpiltter; {k4)f ad\  
?6;9r[ p  
\':'8:E  
} q#RUL!WF7U  
m5c?A+@fZ  
"]1 !<M6\i  
public String getSSiteURL() zPzy 0lx  
{ TYv'#{  
return sSiteURL; F xek#  
} or~2r8  
|]--sUx:  
>|{n";n&  
public void setSSiteURL(String value) ,E8:!r)6  
{ UoAHy%Y<%  
sSiteURL = value; 0,b.;r  
} d}@b 3   
b#~K>  
Z^tTR]u\$  
public String getSFilePath() O52B  
{ J,iS<lV_  
return sFilePath; B*0TM+  
} @c;XwU]2t  
>:o$h2  
(G1KMy  
public void setSFilePath(String value) C{{RU7iqc&  
{ F,dPmR  
sFilePath = value; `$PdI4~J  
} .rPg  
Nxm^jPM 0  
W;Y"J_  
public String getSFileName() ke2zxX2 f  
{ /penB[ 1i  
return sFileName; 6Qc *:(GE  
} qjr:(x/  
9%#u,I  
Z;ze{Vb  
public void setSFileName(String value) plNoI1st  
{ %I^schE*  
sFileName = value; 7MbV|gM}  
} L`2(u!i J  
$)YalZ  
r+Pfq[z&  
public int getNSplitter() fw&cv9X(IU  
{ yac4\%ze  
return nSplitter; +X%pUe  
} po! [Nd&"  
W{$J)iQ  
xcQD]"   
public void setNSplitter(int nCount) R@df~  
{ <)$e*HrI  
nSplitter = nCount; +B '<0  
} Vg^yjP{sv  
} Leu6kPk  
7VIfRN{5n  
j'uzjs[  
/* r1&eA%eh  
**Utility.java 2!)|B ;y  
*/ IKrojK8-?  
package NetFox; 2RU/oqmR  
gJ H^f3  
F05]6NVv  
public class Utility { 7](aPm8  
v8"Zru  
 \4j(el  
public Utility() /g>]J70  
{ 3dx.%~c  
I]z4}#+cX  
% !>@m6JK  
} >~l^E!<i-u  
en"\2+{Cg  
//线程睡眠 jL{k!V`s  
public static void sleep(int nSecond) s-4qK(ml-  
{ vX?C9Fr2  
try{ c;,-I  
Thread.sleep(nSecond); 6`@6k2]  
} 1j]vJ4R_\  
catch(Exception e) 12V-EG i  
{ g;7W%v5wqk  
e.printStackTrace (); ?jU 3%"  
} ,:{+-v(  
} R_=fH\c;  
(+nnX7V?I  
//日志 Eb8~i_B-  
public static void log(String sMsg) kZ0z]Y  
{ BxiR0snf0q  
System.err.println(sMsg); g^{a;=  
} .IsOU  
Rw<O%i5/d  
qN^]`M[ BY  
public static void log(int sMsg) 09=w  
{ `NyO|9/4  
System.err.println(sMsg); DB0?H+8t  
} ~i]4~bkH2  
} P\h1%a/D  
`[h&Q0Du6  
I0N~>SpZ5  
/* xxG>Leml  
**TestMethod.java lSy_cItF  
*/ )Wk&c8|y  
package NetFox; 9 RC:-d;;_  
D|2lBU  
S3Fj /2Q8  
public class TestMethod { RLO<5L  
/Ri-iC >  
O' Mma5  
public TestMethod() 4O4}C#6(4  
{ ///xx/weblogic60b2_win.exe a_z f*;  
try{ H|3CZ=U?  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qykI[4  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mj ,Oy  
SiteFileFetch fileFetch = new SiteFileFetch(bean); @>F`;'_*z  
fileFetch.start(); P!!:p2fo  
} !,~C  
catch(Exception e){e.printStackTrace ();} N.vkM`Z  
(\4YBaGd  
aW#^@||B  
} Uo JMOw[  
Q) iN_|  
A QPzId*z  
public static void main(String[] args) +WvW#wpH  
{ ||;a#FZ^  
new TestMethod(); w!RJ8  
} lgC^32y  
} 5 HN,y  
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