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http断点续传简单实现(java)

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/* =36e&z-#  
**SiteFileFetch.java 1VH$l(7IQ  
*/ Fp`MX>F  
package NetFox; bc".R]  
import java.io.*; T{L{<+9%  
import java.net.*; SiM1Go}#  
@_O,0d g  
XyS|7#o  
public class SiteFileFetch extends Thread { _QhB0/C  
xEA%UFB.!G  
]{[8$|Mg  
SiteInfoBean siteInfoBean = null; //文件信息Bean ?^# h|aUp.  
long[] nStartPos; //开始位置 dZ kr#>  
long[] nEndPos; //结束位置 *@C4~Zo  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 !Gphs`YI  
long nFileLength; //文件长度 P@u&~RN9f+  
boolean bFirst = true; //是否第一次取文件 Rilr)$  
boolean bStop = false; //停止标志 9O%4x"*PO  
File tmpFile; //文件下载的临时信息 )ny,vcU]  
DataOutputStream output; //输出到文件的输出流 Rj/9\F3H  
T}?vp~./   
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) w'Kc#2  
public SiteFileFetch(SiteInfoBean bean) throws IOException ddR_+B*H  
{ s 4Mi9h_  
siteInfoBean = bean; 05|,-S  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); dXe. 5XC  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ,r,~1oV<"  
if(tmpFile.exists ()) w(P\+ m<%  
{ f> u{e~Q,  
bFirst = false; 7Y8B \B)w  
read_nPos(); +dkbt%7M  
} )BuS'oB  
else  n(mS  
{ }> 51oBgk_  
nStartPos = new long[bean.getNSplitter()]; e<wRA["  
nEndPos = new long[bean.getNSplitter()]; 0P5!fXs*  
} 9}4EW4  
)6S;w7  
"dKYJ&$  
$J~~.PUXQ  
} +Oae3VFf;  
>gt_C'  
XZcT-w 7  
public void run() xr2ew%&o  
{ u% ^Lu.l_c  
//获得文件长度 I92c!`{  
//分割文件 NZ\aK}?~!  
//实例FileSplitterFetch !eoN  
//启动FileSplitterFetch线程 F4m Q#YlrS  
//等待子线程返回 8tc9H}>  
try{ FmALmS  
if(bFirst) ,|: a7b]  
{ sFEkxZi<  
nFileLength = getFileSize(); /mB'Fn6)  
if(nFileLength == -1) a{lDHk`Wf  
{ !lSxBr[dQ  
System.err.println("File Length is not known!"); c=YJ:&/5&  
} b&$ ?.z  
else if(nFileLength == -2) =A6/D    
{ `0r=ND5.  
System.err.println("File is not access!"); X^tVq..0  
} oCLs"L-r{  
else 3^LSK7.:  
{ I5"ew=x#  
for(int i=0;i<nStartPos.length;i++) M y:9  
{ CqXD z  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); -DO*,Eecv  
} w"CcWng1  
for(int i=0;i<nEndPos.length-1;i++) ~3 {C &c  
{ \ B~9Ue!  
nEndPos = nStartPos[i+1]; zS Yh ?NB5  
} LhZWK^!{S  
nEndPos[nEndPos.length-1] = nFileLength; /H)K_H#|;  
} o W)M&$oS  
} n'/w(o$&  
:!a9|Fh~  
:<%q9)aPf`  
//启动子线程 n2bL-  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mm3goIi; Y  
for(int i=0;i<nStartPos.length;i++) n6gYZd  
{ S7Xr~5>X  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J&{qe@^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WgdL^PN(h  
nStartPos,nEndPos,i); 9Z0(e!b4S  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WUid5e2  
fileSplitterFetch.start(); /j]r?KAzw  
} @!\ g+z_"  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p{j }%) 6n  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @:@0}]%z9  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,L+tm>I  
nEndPos = " + nFileLength); n:?fv=9n  
// fileSplitterFetch[nPos.length-1].start(); ^4LkKYMS  
F|*{Ma  
d{.cIv  
//等待子线程结束 a;Ic!:L  
//int count = 0; {~ yj]+Im  
//是否结束while循环 PUB|XgQDY:  
boolean breakWhile = false; =*.Nt*;;  
4z-sR/d  
3G9YpA_}X  
while(!bStop) b#-5b%ON  
{ pti`q )  
write_nPos(); 9i)E<.6  
Utility.sleep(500); LxkToO{  
breakWhile = true; XD`QU m  
4BG6C'`%  
L<>;E  
for(int i=0;i<nStartPos.length;i++) tb7Wr1$<  
{ #Zpp*S55  
if(!fileSplitterFetch.bDownOver) 8<$6ufvOv  
{ j380=? 7  
breakWhile = false; Q p7|p  
break; cL&V2I5O  
} bz_Zk  
} lgZ3=h  
if(breakWhile) 4Vj|k\vE4  
break; Lj"~6l`)  
xm>RLx}9  
DCb\ =E  
//count++; ze Qgg|;  
//if(count>4) c,KT1me  
// siteStop(); YzU(U_g$  
} ;YxQo o >  
v*5n$UFV  
W|@EKE.k  
System.err.println("文件下载结束!"); (US]e un  
} OpY2Z7_  
catch(Exception e){e.printStackTrace ();} %R5APMg1  
} n.C.th >Y1  
=+q9R`!L]  
BVxg=7%St  
//获得文件长度 }cyHR1K  
public long getFileSize() #Nxk3He]8  
{ 2O {@W +Mt  
int nFileLength = -1; @FL?,_,Y{  
try{ XOO!jnQu  
URL url = new URL(siteInfoBean.getSSiteURL()); St&xe_:^<  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~.M{n&NM  
httpConnection.setRequestProperty("User-Agent","NetFox"); bD<[OerG  
9|T%q2O  
nM  D^x  
int responseCode=httpConnection.getResponseCode(); ahkSEE{  
if(responseCode>=400) |")}p=   
{ [JFmhLP9  
processErrorCode(responseCode); `pF|bZ?v  
return -2; //-2 represent access is error \pZ,gF;y  
} 4EzmH)4G  
#M6@{R2_  
o)'T#uK  
String sHeader; %y33evX/B  
s bd;Kn  
*52*IRH  
for(int i=1;;i++) go/]+vD  
{ 5n1;@Vr  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xL4qt=  
//Utility.log(in.readLine()); $ud5bT{n  
sHeader=httpConnection.getHeaderFieldKey(i); DW@PPvfs  
if(sHeader!=null) y]9 3z!#Z  
{ m/n_e g  
if(sHeader.equals("Content-Length")) ys:1%D,,_  
{ `pzp(\lc  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e0"R7a  
break; tfj6#{M5  
} i$)bZr\  
} =,KRZqz  
else &TE=$a:d&  
break; 9 )u*IGj  
} 6 k+FTDL  
} CJk$o K{Q  
catch(IOException e){e.printStackTrace ();} H r?G_L  
catch(Exception e){e.printStackTrace ();} .&.j?kb  
O^hWG ~o  
4H8vB^  
Utility.log(nFileLength); AD =@  
Ae:(_UJz  
npg.*I/>  
return nFileLength; 0 V*Di2  
} ~WU _u,:  
U?JZ23>bbw  
>- ]tOH,0  
//保存下载信息(文件指针位置) kVw5z3]Xg  
private void write_nPos() KgX~PP>  
{ *}Zd QJL  
try{ cBM A.'uIL  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ),0_ C\  
output.writeInt(nStartPos.length); 8I04Nx  
for(int i=0;i<nStartPos.length;i++) oAe]/j$  
{ ]K0<DO9  
// output.writeLong(nPos); UA/Q3)  
output.writeLong(fileSplitterFetch.nStartPos); m v%fX2.  
output.writeLong(fileSplitterFetch.nEndPos); lz@fXaZM  
} szMh}q"u  
output.close(); LYNd^}  
} :U)q(.53  
catch(IOException e){e.printStackTrace ();} \%=\_"^?  
catch(Exception e){e.printStackTrace ();} ln)_Jf1r  
} 8s pGDg\g  
CL|t!+wU/  
_KC)f'Cx  
//读取保存的下载信息(文件指针位置) ej>8$^y  
private void read_nPos() ]p:x,%nm  
{ < i"U%Ds(  
try{ {NXc<0a(  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v'Gqdd-#)  
int nCount = input.readInt(); 9kL'"0c  
nStartPos = new long[nCount]; Ra<mdteZT  
nEndPos = new long[nCount]; 9r@r\-  
for(int i=0;i<nStartPos.length;i++) :pcKww|V  
{ }UZ$<81=  
nStartPos = input.readLong(); 6Lz{/l8  
nEndPos = input.readLong(); -X5rGp++  
} dG}fpQ3&  
input.close(); X{\>TOk   
} +[8s9{1{C  
catch(IOException e){e.printStackTrace ();} mb~w .~%  
catch(Exception e){e.printStackTrace ();} 048BQ  
} v5i[jM8  
!OekN,6  
:.f =>s]  
private void processErrorCode(int nErrorCode) pa Uh+"y>  
{ F.ryeOJ  
System.err.println("Error Code : " + nErrorCode); PcC9)x  
} p>h B&h  
2<)63[YO  
Fh9`8  
//停止文件下载 ~Y@(  
public void siteStop() e4u$+  
{ qCOv4b`  
bStop = true; >/nS<y>  
for(int i=0;i<nStartPos.length;i++) VS@o_fUx)  
fileSplitterFetch.splitterStop(); kX."|]  
E8J `7sa  
%h 6?/  
} )Xg,;^  
} zI8Q "b  
//负责部分文件的抓取 A>(m}P  
**FileSplitterFetch.java *,{. oO9#  
*/ ;H /*%2  
package NetFox; 2+ F34  
&^FCp'J-  
iq-n(Rfw~  
import java.io.*; 2-j+-B|i  
import java.net.*; ,.uu/qV}w  
RzQ1Wq  
55MsF}p  
public class FileSplitterFetch extends Thread { 8:0QIkqk  
/ *xP`'T  
JVf8KHDj  
String sURL; //File URL `DIIJ<;g  
long nStartPos; //File Snippet Start Position ^-c j=on=Q  
long nEndPos; //File Snippet End Position hNmC(saMGm  
int nThreadID; //Thread's ID A U9Y0<  
boolean bDownOver = false; //Downing is over GLQ1rT  
boolean bStop = false; //Stop identical R<{bb'  
FileAccessI fileAccessI = null; //File Access interface G$ XvxJ  
~V[pu  
%sP C3L  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zg+78  
{ N[d*_KN.!  
this.sURL = sURL; [ \ LA  
this.nStartPos = nStart; f;`pj`-k%  
this.nEndPos = nEnd; dX{|-;6vm  
nThreadID = id; N~ _GJw@  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zvYkWaa_Qz  
} xu(5U`K  
L0ig%  
E ;65kZ  
public void run() y[Zl,v7  
{ S-WD?BF C  
while(nStartPos < nEndPos && !bStop) 7S LJLn3d  
{ Ac'[(  
f305yo  
I]bqle0M  
try{ PN[ `p1F  
URL url = new URL(sURL); 1%Xwk2l,8b  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uFOxb}a9v  
httpConnection.setRequestProperty("User-Agent","NetFox"); m5Q,RwJ!xK  
String sProperty = "bytes="+nStartPos+"-"; &$tBD@7  
httpConnection.setRequestProperty("RANGE",sProperty); `}#(Ze*V:  
Utility.log(sProperty); =Ig'Aw$x  
v Ic 0V  
3P~I' FQ  
InputStream input = httpConnection.getInputStream(); u@5vK2  
//logResponseHead(httpConnection); /:d03N\9k  
_}R?&yO  
_R<eWp  
byte[] b = new byte[1024]; ewg&DBbN"  
int nRead; Gf\Dc   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LvgNdVJDP|  
{ [>QV^2'Z  
nStartPos += fileAccessI.write(b,0,nRead); W&ya_iP~C  
//if(nThreadID == 1) !c[(#g  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \c3zK|^  
} ^ }Rqe  
A|1 TE$  
/uS(Z-@  
Utility.log("Thread " + nThreadID + " is over!"); e}yoy+9  
bDownOver = true; r,X5@/  
//nPos = fileAccessI.write (b,0,nRead); z=:<]j#=  
} -jnx0{/  
catch(Exception e){e.printStackTrace ();} |ybW  
} n#t{3qzpD  
} .ii9-+_  
l_GvdD  
dOh'9kk3  
//打印回应的头信息 ] C_g: |q  
public void logResponseHead(HttpURLConnection con) =G3O7\KmH  
{ S453oG"  
for(int i=1;;i++) l?v`kAMR  
{ &cztUM(  
String header=con.getHeaderFieldKey(i); ,}2yxo;i  
if(header!=null) H$TYp  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0KO_bF#EB=  
Utility.log(header+" : "+con.getHeaderField(header));  {I+   
else 6I GUp  
break; / 1 lIV_Z  
} s `fIeP  
} u,e'5,`N  
{$z)7s  
H((! BRl  
public void splitterStop() L&M6s f$N  
{ :W(3<D7\  
bStop = true; LWE[]1=  
} nlJ~Q_E(  
o:B?gDM  
. [DCL  
} /3->TS  
qa wb9Iud0  
^_ <jg0V  
/* c=]qUhnH  
**FileAccess.java w6DK&@w`'/  
*//文件访问(定位,写) y%)5r}S^  
package NetFox; rOQhS]TP*  
import java.io.*; Bf!i(gM  
s$`g%H>  
Ci6yH( RE  
public class FileAccessI implements Serializable{ hV|pH)Nu{  
Bv_C *vW  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q<W9<&VZe  
RandomAccessFile oSavedFile; Jv1igA21_h  
long nPos; 3"=% [  
0jCYOl  
^{&Vv(~!Q  
public FileAccessI() throws IOException H?98^y7  
{ Xr\|U89P  
this("",0); 1;cV [&3  
} le*mr0a  
uU(G&:@  
6OR5zXpk  
public FileAccessI(String sName,long nPos) throws IOException %}jwuNGA  
{ 9k8ftxB^  
oSavedFile = new RandomAccessFile(sName,"rw"); -BUxQ8/,  
this.nPos = nPos; x)0g31 4 9  
oSavedFile.seek(nPos); 9t@^P^}=\m  
} ?h UC#{  
4GWt.+{J$  
YVt#( jl  
public synchronized int write(byte[] b,int nStart,int nLen) nM:e<`r  
{ p'UYH t  
int n = -1; ]:`q/iS&  
try{ :q=u+h_  
oSavedFile.write(b,nStart,nLen); 02E-|p;  
n = nLen; "&?F 6Pi  
} 3Tze`Q 9  
catch(IOException e) y~'F9E!i  
{ ppr95 Y]^  
e.printStackTrace (); d%_v eVIe  
} ].53t"*  
(pM5B8U  
S|!)_RL  
return n; a@`15O:  
} f`'?2  
K=Z~$)Og)  
ULc oti=,  
} ^$qr6+  
z-fP #.  
[uK*=K/v  
/* ] -"~?  
**SiteInfoBean.java s\ft:a@  
*/ IJHNb_Cku  
package NetFox; 0,+RF "R  
%T@3-V_  
gTWl];xja  
public class SiteInfoBean { MMg"G6?  
[of{~  
\Z9+U:n  
private String sSiteURL; //Site's URL hZ NS$  
private String sFilePath; //Saved File's Path 7=C$*)x  
private String sFileName; //Saved File's Name 1gk{|keh  
private int nSplitter; //Count of Splited Downloading File K6<@DP+/  
y1R53u`;L  
K{)N:|y%!$  
public SiteInfoBean() 1}+lL)-!  
{//nSplitter的缺省值为5 1A\Jh3;Q  
//default value of nSplitter is 5 i zJa`K  
this("","","",5); mh`~1aEr  
} Eukj2 a  
)RA$E`!b  
QX}O{LQR  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0'y9HE'e  
{ ,E,oz{,i(  
sSiteURL= sURL; *,q W9z  
sFilePath = sPath; S <~"\<ED  
sFileName = sName; X,VOKj.%  
this.nSplitter = nSpiltter; '>dsROB->  
3vRRL  
|9>?{ B\a  
} _kUf[&  
@IL_  
}T=0]u4,  
public String getSSiteURL() S9kagiFX\  
{ 8a{S*  
return sSiteURL; BeP]M1\?>  
} q#9JJWSs  
>7%Gd-;l  
CVfQ  
public void setSSiteURL(String value) $1<V'b[E  
{ +Hx$ABH  
sSiteURL = value; [1{#a {4  
} MX!t/&X(n  
p6~\U5rXm  
mFCDwh]  
public String getSFilePath() db$wKvO1  
{ 0<f\bY02  
return sFilePath; v+XB$j^H  
} H]e%8w))0  
sevaNs  
p)l>bC?3  
public void setSFilePath(String value) 4+&4  
{ 3S4'x4*  
sFilePath = value; 5J!ncLNm{  
} 3[8F:I0UL  
|"V]$s$ c  
s5{N+O)~S  
public String getSFileName() Fw ,'a  
{ >C,=elM  
return sFileName; QC@nRy8%  
} S[p.`<{J  
3^p<Wx  
/C)mx#h]  
public void setSFileName(String value) bvdAOvxChW  
{ pqmb&"l  
sFileName = value; .b'o}DLa  
} ygt7;};!  
cQkH4>C~  
9WN 4eC$  
public int getNSplitter() p.{9OrH(4  
{ r&F(VF0 6  
return nSplitter; W 2/`O?  
} y bWb'+x  
Vgy}0pCl  
E-Z6qZ^  
public void setNSplitter(int nCount) D)C^'/8q  
{ &8VB{S>r  
nSplitter = nCount; b[+G+V   
} ^7Sk`V  
} [k~V77w 14  
R5 O{;/w  
MExP'9  
/* +E.}k!y  
**Utility.java i4 BCm/h  
*/ 8r"$o1!  
package NetFox; 6J/"1 _  
jP*5(*[&y  
DRS68^  
public class Utility { {&tbp Bl#  
+ 3+^J?N  
fq*. 4s #  
public Utility() ?-"xP'#  
{ RU} M&&  
6=ukR=]v  
y$6m|5  
} -]8cw#y 0A  
3;fuz Kk@b  
//线程睡眠 _-^bAr`z  
public static void sleep(int nSecond) S3cjw9V  
{ *}BaO*A  
try{ MUo}Qi0K  
Thread.sleep(nSecond); Z";~]]$!Y  
} K9JW&5Q  
catch(Exception e) x!6&)T?!n  
{ U@ #YKv  
e.printStackTrace (); =4RXNWkud  
} x13t@b  
} y+3< ] N  
B8Ob~?  
//日志 }e}J6 [wP  
public static void log(String sMsg) H(qDQqJHYy  
{ W<Ms0  
System.err.println(sMsg); &,?bX])  
} f{ZOH<"Lo  
4;G:.k!K  
:?1r.n  
public static void log(int sMsg) J*)Vpk  
{ CiE  
System.err.println(sMsg); h-0sDt pR  
} 'FB?#C%U  
} 6=V&3|"  
T /iKz  
Yh`P+L  
/* p-]vf$u  
**TestMethod.java &\(p<TF  
*/ W/*2I3a  
package NetFox; ,TrrqCw>  
dP8b\H  
$umh&z/  
public class TestMethod { WfbG }%&J  
Y02 cX@K6  
SKTf=rY  
public TestMethod() 5<o8prt B  
{ ///xx/weblogic60b2_win.exe j$l[OZ:#  
try{ /S29\^  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lR5< G  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Wn*>h'R  
SiteFileFetch fileFetch = new SiteFileFetch(bean); #:rywz+  
fileFetch.start(); IooAXwOF  
}  3*@ sp  
catch(Exception e){e.printStackTrace ();} r^3QDoy  
%'2DEt??  
j{)_&|^{  
} #X&`gDW  
y,$kU1yH7  
fmH"&>Loc  
public static void main(String[] args) CXqU< a&  
{ )6?(K"T  
new TestMethod(); a]NQlsE}l  
} an+`>}]F  
} lq2P10j@  
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