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http断点续传简单实现(java)

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/*  #u~8Txt  
**SiteFileFetch.java )lZb=t  
*/ %EuSP0  
package NetFox; `!i>fo~  
import java.io.*; <*L8kNykK  
import java.net.*; E:2Or~  
NunT1ved  
[Mx+t3M  
public class SiteFileFetch extends Thread { p|zW2L  
x`4">:IA  
[8ih-k  
SiteInfoBean siteInfoBean = null; //文件信息Bean o.,hCg)X  
long[] nStartPos; //开始位置 "zugnim  
long[] nEndPos; //结束位置 ?n}L+|  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 c5JxKU_  
long nFileLength; //文件长度 BwR)--75  
boolean bFirst = true; //是否第一次取文件 IMj{n.y4  
boolean bStop = false; //停止标志 ;*8$BuD  
File tmpFile; //文件下载的临时信息 .A E(D7d6  
DataOutputStream output; //输出到文件的输出流 Yv>% 5`  
[,VD^\  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) |g~.]2az  
public SiteFileFetch(SiteInfoBean bean) throws IOException xu3qX"  
{ Ra/S46$  
siteInfoBean = bean; #<{sP 0v*  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); =7a9~&|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); sPut@4[S  
if(tmpFile.exists ()) Lx.X#n.]T  
{ ~MOIrF  
bFirst = false; -0Ps. B  
read_nPos(); '2eggX%  
} O[!]/qP+.  
else 4g|}]K1s  
{ FbF P  
nStartPos = new long[bean.getNSplitter()]; WHL@]^E@m  
nEndPos = new long[bean.getNSplitter()]; qTG/7tn "  
} |1#*`2j\=9  
s q_ f[!  
\]zH M.E1  
ikUG`F%W  
} 8< R#}  
W_%Dg]l   
F8q|$[nH  
public void run() ^5OR%N)  
{ HN\9 d  
//获得文件长度 0y*8;7-|r)  
//分割文件 Uo# Pe@ieQ  
//实例FileSplitterFetch W 5-=,t  
//启动FileSplitterFetch线程 Esd A %`  
//等待子线程返回 d4~!d>{n|c  
try{ ZjWI~"]  
if(bFirst) />H9T[3=  
{ up1kg>i%"  
nFileLength = getFileSize(); t\ ym4`"  
if(nFileLength == -1) s~3"*,3@  
{ {>9vm!<[*\  
System.err.println("File Length is not known!"); `2G 0B@  
} ^)TZHc2a[  
else if(nFileLength == -2) @u?m4v{  
{ qeypa !  
System.err.println("File is not access!"); nPE{Gp) }  
} T< D&%)  
else ta %yQd7  
{ G@s rQum(  
for(int i=0;i<nStartPos.length;i++) `#R[x7bA1  
{ W2'u]1bs  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); &=~Jw5WK  
} S3$&}I <  
for(int i=0;i<nEndPos.length-1;i++) C h>r.OfP  
{ )m|)cLT&  
nEndPos = nStartPos[i+1]; f]Xh7m(Gh  
} UZz/v#y~  
nEndPos[nEndPos.length-1] = nFileLength; `f S$@{YI_  
} ]@0C1 r  
} )1N~-VuT  
Dr)B0]KG  
7*.nd  
//启动子线程 h:xvnyaI  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <v%Q|r  
for(int i=0;i<nStartPos.length;i++) 0-6rIdDTM  
{ :pq+SifP  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -e(e;e  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `p#tx.o  
nStartPos,nEndPos,i); Zcjh  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x.8fxogz  
fileSplitterFetch.start(); LtW}R4}3  
} O |!cPB:  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k..AP<hH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }20~5!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uVN2}3!)Y  
nEndPos = " + nFileLength); f?W_/daP  
// fileSplitterFetch[nPos.length-1].start();  4 Fl>XM  
]Q$Sei5  
t^ Ge "  
//等待子线程结束 !Ah v07SI  
//int count = 0; )Vd^#p  
//是否结束while循环 $t0o*i{  
boolean breakWhile = false; f\xmv|8  
- ({h @  
{.eo?dQ  
while(!bStop) *O_>3Hgl  
{ >jz9o9?8  
write_nPos(); xu\s2x$  
Utility.sleep(500); w$iQ,--  
breakWhile = true; MroN=%|t  
xIA]5@;a  
pmRm&VgE.  
for(int i=0;i<nStartPos.length;i++) KrdEB0qh  
{ 5\V""fH  
if(!fileSplitterFetch.bDownOver) [4w*<({*  
{ agt/;>q\~  
breakWhile = false; Hsn'"  
break; z^vfha  
} qA0PGo  
} iYD5~pK8  
if(breakWhile) e.\dqt~%y  
break; <p/zm}?')  
DG?g~{Y~b  
-U*J5Q  
//count++; SSxp!E'  
//if(count>4) ,.Lwtp,n  
// siteStop(); DSQ2|{   
} 9TX2h0U?  
+-C.E  
bgLa`8  
System.err.println("文件下载结束!"); kM J}sS  
} \HXq~Y  
catch(Exception e){e.printStackTrace ();} 60;_^v  
} eSQkW  
d~ +(g!  
EHN(K-  
//获得文件长度 OClG dFJ|  
public long getFileSize() NOg/rDs'{  
{ 0<7sM#sI!  
int nFileLength = -1; k4a51[SYBK  
try{ _3(rwD  
URL url = new URL(siteInfoBean.getSSiteURL()); Unvl~lm6  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \3OEC`  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ge_fU'F  
Q3Pu<j}Y  
URceq2_  
int responseCode=httpConnection.getResponseCode(); "AU.Eh"-1  
if(responseCode>=400) >"8;8Ev  
{ 3~{I/ft  
processErrorCode(responseCode); }4N'as/ZO  
return -2; //-2 represent access is error 8OKG@hc  
} qg{gCG  
7HkFDI()1  
}f;WYz5  
String sHeader; :.4O Hp1  
T%% 0W J  
9dq"x[  
for(int i=1;;i++) }4p)UX>aWT  
{ Li]bU   
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b"WF]x|^  
//Utility.log(in.readLine()); b"uO BB  
sHeader=httpConnection.getHeaderFieldKey(i); ckMG4 3i\j  
if(sHeader!=null) \_WR:?l  
{ %cLS*=MO  
if(sHeader.equals("Content-Length")) jYi,oE  
{ C7ug\_,s  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $2\ 8Rn6'  
break; ~5'7u-;  
} s3eS` rK-  
} UAPd["`)y  
else Lo3N)~5  
break; :h5G|^  
} $m;`O_-T  
} y{/7z}d  
catch(IOException e){e.printStackTrace ();} 0KnL{Cj   
catch(Exception e){e.printStackTrace ();} M^[;{p2uZ  
_tJt eDRY  
jB8Q% {%  
Utility.log(nFileLength); ele@xl  
<Xl#}6II  
%ggf|\ -e  
return nFileLength; P&sWn?q Ol  
} )w0x{_  
s EFQ8S  
@QV0l]H0+  
//保存下载信息(文件指针位置) *#'j0;2F  
private void write_nPos() tBbOxMm0  
{ PQDLbSe)\  
try{  +=jS!  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Bhxs(NO  
output.writeInt(nStartPos.length); :~ pGHl  
for(int i=0;i<nStartPos.length;i++) 3("C'(W  
{ KEtV  
// output.writeLong(nPos); Sp492W+  
output.writeLong(fileSplitterFetch.nStartPos); Xd=KBB[r?  
output.writeLong(fileSplitterFetch.nEndPos); gzIx!sc  
} [02rs@c>  
output.close(); tGgxID  
} /kY9z~l  
catch(IOException e){e.printStackTrace ();} db~^Gqv6k  
catch(Exception e){e.printStackTrace ();} 5>I-? Ki  
} JcWp14~e  
4d`YZNvZW/  
qFD ZD)K  
//读取保存的下载信息(文件指针位置) 3Rc*vVnI  
private void read_nPos() 4~,Z 'k  
{ d #1Y^3n  
try{ H"FK(N\  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *{3d+j/?/  
int nCount = input.readInt(); lG)wa  
nStartPos = new long[nCount]; \P*_zd@%  
nEndPos = new long[nCount]; l)9IgJ|<b  
for(int i=0;i<nStartPos.length;i++) bZNqv-5 4h  
{ B W<Dmn  
nStartPos = input.readLong(); Z#Mm4(KNh  
nEndPos = input.readLong(); se\fbe^0  
} m,lZy#02s3  
input.close(); ^1najUpQ_n  
} $DoR@2 ~y  
catch(IOException e){e.printStackTrace ();} -N8rs[c  
catch(Exception e){e.printStackTrace ();} x="Wqcnj{  
} P9/ (f$=  
^+SE_-+]  
7q+D}+ Xf  
private void processErrorCode(int nErrorCode) 1(gs({  
{ q#tUDxf(|  
System.err.println("Error Code : " + nErrorCode); bZ\R0[0  
} s0/O/G?  
$D1ha CL  
itg_+%^R  
//停止文件下载 j(=w4Sd_W  
public void siteStop() h m,{C  
{ (-gomn  
bStop = true; h^SWb9 1"G  
for(int i=0;i<nStartPos.length;i++) `gX|q3K\s  
fileSplitterFetch.splitterStop(); D5,]E`jwu  
oZa'cZNs  
J,F1Xmr4  
} 8M99cx*K  
} fOV_ >]u  
//负责部分文件的抓取 lI<jYd 0fZ  
**FileSplitterFetch.java GGp.u@\r  
*/ uzBQK  
package NetFox; sp,-JZD  
oX|T&"&  
e9o\qEm   
import java.io.*; 9MMCWMV  
import java.net.*; G&ck98  
0 0N[ : %  
.xN<<+|_v'  
public class FileSplitterFetch extends Thread { AJ\&>6GZ(b  
zmo2uUEd  
i "h\*B=  
String sURL; //File URL % T({;/  
long nStartPos; //File Snippet Start Position Sc7 Ftb%  
long nEndPos; //File Snippet End Position  >Uw:cq  
int nThreadID; //Thread's ID )0VL$A  
boolean bDownOver = false; //Downing is over jE*{^+n  
boolean bStop = false; //Stop identical 7*l$ i/!  
FileAccessI fileAccessI = null; //File Access interface z`zz8hK.  
A7% d  
lU{)%4e`  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $Zu?Gd?  
{ +V4)><  
this.sURL = sURL; gJQ#j~'  
this.nStartPos = nStart; :W.H#@'(  
this.nEndPos = nEnd; rYb5#aT[  
nThreadID = id; )9hqd  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WC#6(H5t$  
} EhxpMTS  
}u_D{bz  
1Gsh%0r3  
public void run() 2_q/<8t  
{ %e~xO x  
while(nStartPos < nEndPos && !bStop) W/qXQORv  
{ L7$f01*  
KN}#8.'>3  
E_ wVAz3  
try{ ` ,\b_SFg  
URL url = new URL(sURL); ("8Hku?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !"N,w9MbD  
httpConnection.setRequestProperty("User-Agent","NetFox"); /6 ')B !&  
String sProperty = "bytes="+nStartPos+"-"; yaR>?[h  
httpConnection.setRequestProperty("RANGE",sProperty); 2lTt  
Utility.log(sProperty); }J#HIE\RG  
*ERV\/  
"t0^4=c+7  
InputStream input = httpConnection.getInputStream(); J :O!4gI  
//logResponseHead(httpConnection); cYA:k  
Xdn&%5rI  
B4y_{V  
byte[] b = new byte[1024]; ZC?~RXL(  
int nRead; t<45[~[  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (Ceruo S  
{ &<t%u[3  
nStartPos += fileAccessI.write(b,0,nRead); }j/\OY _&  
//if(nThreadID == 1) Rw?w7?I  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "*bLFORkq'  
} /HdXJL9B  
74([~Qs _M  
T8S&9BM7  
Utility.log("Thread " + nThreadID + " is over!"); ]3 "0#Y  
bDownOver = true; &W\e 5X<A  
//nPos = fileAccessI.write (b,0,nRead); W`[VLi}fe  
} `i`P}W!F  
catch(Exception e){e.printStackTrace ();} ,;pUBrz/[  
} dcf,a<K\  
} jr` swyg  
!]F`qS>  
I): c#  
//打印回应的头信息  "9;  
public void logResponseHead(HttpURLConnection con) HxO+JI`'3  
{ A?MM9Y}K  
for(int i=1;;i++) TAYh#T=S  
{ [j6]!p]S$  
String header=con.getHeaderFieldKey(i); V D#q\  
if(header!=null) sl$6Zv-l%0  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^(q .f=I!a  
Utility.log(header+" : "+con.getHeaderField(header)); .q 2r!B  
else Bl+\|[yd  
break; uuM1_nD[  
} sVh)Ofn  
} I#OZ:g^  
}ILBX4c  
2hHRitt36  
public void splitterStop() I bD u+~)  
{ tR!C8:u  
bStop = true; |>ztx}\  
} )<QX2~m<  
~>@~U]  
ew\:&"@2]w  
} &b (*  
/` M#  
e#oK% {A  
/* ;r@=[h   
**FileAccess.java 7&id(&y/  
*//文件访问(定位,写) ,1I-%6L  
package NetFox; {iyJ HY  
import java.io.*; N^QxqQ~  
LuZlGm  
/4+L2O[  
public class FileAccessI implements Serializable{ .s\lfBo9  
2*sTU  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &<><4MQ  
RandomAccessFile oSavedFile; M[qhy.  
long nPos; ?b7ttlX{  
{J"]tx9 ]  
^|<>`i6  
public FileAccessI() throws IOException 7)U ik}0  
{ 3FvVM0l"  
this("",0); Fx!D:.)/G  
} MsIR~  
E{)X ;kN=  
4rDV CXE  
public FileAccessI(String sName,long nPos) throws IOException ;=joQWNDm  
{ T`^Jw s{;7  
oSavedFile = new RandomAccessFile(sName,"rw"); e#hg,I  
this.nPos = nPos; ;8<HB1 &,  
oSavedFile.seek(nPos); oLkzLJ  
} g{Av =66Z  
ASdW!4.p  
=R:O`qdC4e  
public synchronized int write(byte[] b,int nStart,int nLen) %f CkR`:  
{ >K'dgJ245  
int n = -1; uG -+&MU?  
try{ 6D ]fDeH\  
oSavedFile.write(b,nStart,nLen); 4M%|N  
n = nLen; /,S VG1  
} qUfoEpW2=6  
catch(IOException e) GLIY!BU<C  
{ '`;=d<'  
e.printStackTrace (); Z'A 3\f   
} qMEd R;o  
0to`=;JI  
nP[Z6h  
return n; KC"S0 6  
} Rk5#5R n  
-0xo6'mD  
a;bmlV04  
} 4Q#{,y944  
yR~$i3Z*  
~0+<-T  
/* zf8SpQ2~  
**SiteInfoBean.java CA|l| t^  
*/ yT:2*sZRc  
package NetFox; rV\G/)xL  
UB+~K/  
/*;a6S8q  
public class SiteInfoBean { '__>M>[  
TfJ*G6\7e#  
uhj]le!  
private String sSiteURL; //Site's URL rI\5djiYJ  
private String sFilePath; //Saved File's Path z#Qe$`4&  
private String sFileName; //Saved File's Name |(l]Xr&O  
private int nSplitter; //Count of Splited Downloading File r<kgYU`  
*A`ZcO=   
UU(Pg{DA 6  
public SiteInfoBean() /t`|3Mw  
{//nSplitter的缺省值为5 e<uf)K=(C  
//default value of nSplitter is 5 w;Azxcw  
this("","","",5); %AJ9fs4/  
} V5-!w0{  
%h(%M'm?  
MtwlZg`c3  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :@5{*o  
{ _1RvK? ;.{  
sSiteURL= sURL; E5A"sB   
sFilePath = sPath; 3f$n8>mq  
sFileName = sName; D5xQ  
this.nSplitter = nSpiltter; CH(Y.Kj-  
dSKvs"  
5s\;7>  
} |X*y-d77W  
VMF?qT3Nd  
v .*fJ   
public String getSSiteURL() $@kOMT  
{ Vo^J2[U  
return sSiteURL; Kn3Xn`P?  
} R`$Y]@i&B  
CAx$A[f<  
W%5))R$  
public void setSSiteURL(String value) I*j~5fsS'  
{ _QHk&-Lp  
sSiteURL = value; [>>_%T\I  
} oQpGa>6U&  
)?OdD7gd  
Kg~D~ +j  
public String getSFilePath() QuMv1)n  
{ G>:v1lde  
return sFilePath; uX!6: v]  
} O13]H"O_  
{/)i}V#RE  
vN v'%;L  
public void setSFilePath(String value) H!0m8LCnb  
{ _\yR/W~  
sFilePath = value; ]%-U~avph  
} 4Th?q{X  
pRh9+1EM;  
[;aM8N  
public String getSFileName() /2d>nj  
{ 1P"{TMd?  
return sFileName; sqpo5~  
} ";`jS&"=  
\IC^z  
L'a+1O1q&i  
public void setSFileName(String value) 4".I*ij  
{ r [^.\&-  
sFileName = value; ._>03,"  
} |AE{rvP{@  
D=vw0Q_3Y3  
#b&tNZ4!_  
public int getNSplitter() pam9wfP  
{ .3UJ*^(?  
return nSplitter; I74Rw*fB  
} h{_\ok C>  
^ )"Il  
CG@Fn\J  
public void setNSplitter(int nCount) 49>b]f,Vc  
{ 4a& 8G  
nSplitter = nCount; eD(5+bm  
} ld#x'/  
} {[:C_Up)f  
r aOuD3  
At[Q0'jkc  
/* |*w)]2B l  
**Utility.java :zo5`[P  
*/ e(0 cz6  
package NetFox; 9[X'9* ,  
.czUJyFms}  
Fhllqh)  
public class Utility { y@$E5sz  
l=" X|t   
P5B,= K>r  
public Utility() YCStX)r  
{ GPGP teC  
H-&27?s^  
^Os }sJ*5S  
} Qp[ Jw?a  
p),* 4@2<  
//线程睡眠 E0VAhN3G\  
public static void sleep(int nSecond) A0@,^|]  
{ FXY>o>K%h  
try{ 8<0P Ssx  
Thread.sleep(nSecond); P 0+@,kM  
} 3f^jy(  
catch(Exception e) h*y+qk-!\g  
{ $Yu'B_E6p  
e.printStackTrace (); $X-PjQb1Bb  
} &R.5t/x_  
} ORP<?SG55u  
1E||ft-1i*  
//日志 XRkUv>Yk  
public static void log(String sMsg) q,#s m'S  
{ IEm~^D#<=  
System.err.println(sMsg); (||qFu9a  
} 'ParMT  
8Uh|V&  
SD*q+Si,1U  
public static void log(int sMsg) z__t8yc3  
{ PN9vg9'  
System.err.println(sMsg); E=,b;S-  
} Oprfp^L  
} s&o9LdL  
I:oEt  
Ebj0 {ZL  
/* w[l#0ZZ  
**TestMethod.java rxMo7px@}I  
*/ =$bF[3D  
package NetFox; NTZ3Np`  
kq(><T  
F~E)w5?\O  
public class TestMethod { 1Zp/EYWa{  
uSI@Cjp  
Y R~e_cA:  
public TestMethod() :ln| n6X  
{ ///xx/weblogic60b2_win.exe Z R=[@Oi  
try{ 2+)h!y]  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "]p&7  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); DFZ@q=ZT  
SiteFileFetch fileFetch = new SiteFileFetch(bean); w0nbL^f  
fileFetch.start(); ):tv V  
} z]%@r 7  
catch(Exception e){e.printStackTrace ();} Jia@HrLR  
W\Scak>  
`Nvhp]E  
} BcpbS%S  
GwDOxH'  
KK >j V  
public static void main(String[] args) _8K8Ai-~.>  
{ JBw2#ry  
new TestMethod(); uA =%EEZ  
} Bx}"X?%S  
} _nzq(m1@  
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