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http断点续传简单实现(java)

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/* &"90pBGK  
**SiteFileFetch.java oNgu- &  
*/ gFsnL*L0  
package NetFox; WsA(8Ck<  
import java.io.*; ^:b%Q O  
import java.net.*; }ph;~og}y  
lS`hJ:  
)N) "O? W9  
public class SiteFileFetch extends Thread { I+) Acy;  
HMUn+kk+  
.js@F/H p  
SiteInfoBean siteInfoBean = null; //文件信息Bean =5JTVF  
long[] nStartPos; //开始位置 Jy,Dcl  
long[] nEndPos; //结束位置 =4;GIiF@  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 IZ2c<B5&  
long nFileLength; //文件长度 R+c  {Pl  
boolean bFirst = true; //是否第一次取文件 6j]pJ]F6  
boolean bStop = false; //停止标志 W^c> (d</  
File tmpFile; //文件下载的临时信息 > 5i(U_`l  
DataOutputStream output; //输出到文件的输出流 zUw9  
=xs{Ov=  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }v'jFIkhI  
public SiteFileFetch(SiteInfoBean bean) throws IOException (5l5@MN  
{ FyXz(l:  
siteInfoBean = bean; K22'XrN  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); KUC (n!  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); -L9I;]:KY  
if(tmpFile.exists ()) w3^>{2iqq  
{ cVzOW|NVx  
bFirst = false; mSWh'1]b.~  
read_nPos(); &ZjQa.-U>  
} pg}9baW?  
else /<(d.6T[}:  
{ ar0y8>]3  
nStartPos = new long[bean.getNSplitter()]; mUj=NRq  
nEndPos = new long[bean.getNSplitter()]; t"0Z=`Wi  
} zh hH A9  
YpFh_Zr[  
^-CQ9r*  
5WR(jl+M  
} AZmABl  
Bn7~p+N  
[!@&t:A  
public void run() zc QFIP  
{ NqsIMCl  
//获得文件长度 p^G:h6|+|  
//分割文件 JRMe( ,u  
//实例FileSplitterFetch =] R_6#  
//启动FileSplitterFetch线程 =[O;/~J%:  
//等待子线程返回 FFTh}>>  
try{ !aSu;Ln  
if(bFirst) ub |tX 'o  
{ t83n`LC  
nFileLength = getFileSize(); uvo2W!  
if(nFileLength == -1) #+2|ZfCn%  
{ rYnjQr2a  
System.err.println("File Length is not known!"); c'=p4Fcm  
} {DPobyvwFk  
else if(nFileLength == -2) _,h hO  
{ R@=Bk(h  
System.err.println("File is not access!"); ^cYm.EHI  
} _)q,:g~fu  
else #,dE)  
{ yNk9KK)  
for(int i=0;i<nStartPos.length;i++) ( }DCy23  
{ :*wnO;eN  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6Xjr0 C+  
} I("J$  
for(int i=0;i<nEndPos.length-1;i++) .\0PyV(  
{ &n% 3rC5{  
nEndPos = nStartPos[i+1]; `(|jm$Q  
} ,q yp2Y7  
nEndPos[nEndPos.length-1] = nFileLength; |w(@a:2 kw  
} wo;`D  
} @u./VK  
d%$'Y|  
Y'NQt?h  
//启动子线程 C7ZU)MEUd/  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LTsG  
for(int i=0;i<nStartPos.length;i++) e[t+pnRh  
{ kLKd O0  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dP(*IOO.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K!q:A+]  
nStartPos,nEndPos,i); 1mw<$'pm0  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~=5vc''  
fileSplitterFetch.start(); X@u-n_  
} mZVYgJQ[  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /cBQE=]6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ju$vuEO  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hSmu"a,S  
nEndPos = " + nFileLength); D.2HM  
// fileSplitterFetch[nPos.length-1].start(); 56Q9RU(M  
pq`Bg`c  
8=^o2&  
//等待子线程结束 MtAD&+3$  
//int count = 0; m/"\+Hv  
//是否结束while循环 jI$}\*g  
boolean breakWhile = false; * %p6+D-C  
sF?N vp  
v*Qr(4  
while(!bStop) i[b?W$]7  
{ U @$Kp>X  
write_nPos(); gk+$CyjJ  
Utility.sleep(500); Xp]tL3-p  
breakWhile = true; *N"bn'>3  
T,h,)|:I^  
P7n+@ L$  
for(int i=0;i<nStartPos.length;i++) &Y2mLPB  
{ GI}h )T  
if(!fileSplitterFetch.bDownOver) pPcn F`A  
{ <!h&h  
breakWhile = false; bdiyS.a-  
break; o6^^hc\  
} "M*Pt  
} +>N/q(l  
if(breakWhile) \*#9Ry^f  
break; UOrf wK  
>= Hcw  
36D-J)-Z  
//count++; ^a@Vn\V1  
//if(count>4) X*Mw0;+T  
// siteStop(); v>TI.;{y  
} dB7E&"f  
/IM5#M5~  
sa8Sy&X"  
System.err.println("文件下载结束!"); 24 S,w>j  
} t@-:e^ v  
catch(Exception e){e.printStackTrace ();} I(r^q"  
} [o)P  
J;Az0[qMR  
&UG7 g  
//获得文件长度 O?omL5  
public long getFileSize() 372ewh3'  
{ jyPY]r  
int nFileLength = -1; \[&~.B  
try{ >a98 H4  
URL url = new URL(siteInfoBean.getSSiteURL()); SE+K"faKQ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); : 0Nd4hA  
httpConnection.setRequestProperty("User-Agent","NetFox"); iulM8"P  
TL(L[  
KYY~ YP  
int responseCode=httpConnection.getResponseCode(); v2 [ l$  
if(responseCode>=400) #;'1aT  
{ _N~h#(  
processErrorCode(responseCode); H"8+[.xBh  
return -2; //-2 represent access is error kStWsc$;+T  
} B[F,D  
>\b=bT@iM  
=)C}u6  
String sHeader; ( q^umw  
o >{+vwK  
XA{ tVh  
for(int i=1;;i++) -\@&^e  
{ [#H$@g|CT  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Zs!)w9y&V  
//Utility.log(in.readLine()); ;pdW7  
sHeader=httpConnection.getHeaderFieldKey(i); :Vq gmn  
if(sHeader!=null) $~4ZuV%  
{ v"Bv\5f,Ys  
if(sHeader.equals("Content-Length")) b w5|gmO  
{ 6/9 A'!4C  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [vpZ3;  
break; &;7\/m*W1  
} V 0R;q  
}  5I5~GH  
else Dm6WSp1|b  
break; N4"%!.Y  
} C^RO@kM  
} elXY*nt8h  
catch(IOException e){e.printStackTrace ();} <1]# E@  
catch(Exception e){e.printStackTrace ();} !G3O!]  
"2(4?P  
yB(^t`)}N  
Utility.log(nFileLength); oQ@X}6B%S  
q%#dx4z&  
3/o-\wWO  
return nFileLength; sj003jeko  
} rixNz@p'%  
~q#UH'=%  
zLue j'  
//保存下载信息(文件指针位置) Zr'VA,v  
private void write_nPos() ihKnZcI$i  
{ y1^<!I  
try{ RH^8"%\  
output = new DataOutputStream(new FileOutputStream(tmpFile)); mKynp  
output.writeInt(nStartPos.length); +](^gaDw<L  
for(int i=0;i<nStartPos.length;i++) ~h?zK 1  
{ oT$w14b  
// output.writeLong(nPos); 6Km@A M]  
output.writeLong(fileSplitterFetch.nStartPos); G_=`&i"4  
output.writeLong(fileSplitterFetch.nEndPos); R`Hyg4?  
} -uN5 DJSW  
output.close(); LX4S}QXw  
} _OP75kv  
catch(IOException e){e.printStackTrace ();} S/ ]2Qt#T  
catch(Exception e){e.printStackTrace ();} erYpeq.  
} *nU7v3D  
d@pD5n=m;  
5[[4A]#T  
//读取保存的下载信息(文件指针位置) ^3IO.`|  
private void read_nPos() $@[6jy  
{ i;`r zsRb  
try{ FVsVY1  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8vK Z;  
int nCount = input.readInt(); $d%m%SZxv  
nStartPos = new long[nCount]; )Ve?1?s '8  
nEndPos = new long[nCount]; He. gl  
for(int i=0;i<nStartPos.length;i++) $/nU0W  
{ YY{S0jnhF  
nStartPos = input.readLong(); FkR9-X<  
nEndPos = input.readLong(); z#GZvB/z)  
} =yOIP@  
input.close(); =9FY;9  
} [F%INl-sy  
catch(IOException e){e.printStackTrace ();} n  !]_o  
catch(Exception e){e.printStackTrace ();} dGf{d7D  
} G%-[vk#]  
Af1mTbf=  
i[@*b/A  
private void processErrorCode(int nErrorCode) {e0cc1Up}  
{ 6;9SU+/  
System.err.println("Error Code : " + nErrorCode); Xa\{WM==;  
} HlgF%\@a+U  
4StiYfae  
|Spy |,/  
//停止文件下载 DY'D]*'7$  
public void siteStop() ,ClGa2O  
{ N^xnx<  
bStop = true; ?SRG;G1  
for(int i=0;i<nStartPos.length;i++) K/KZ}PI-O  
fileSplitterFetch.splitterStop(); 6:i{_YX(.S  
7NV1w*> /  
L|EvI.f  
} a,x-akZWf  
} L0Bcx|)"$`  
//负责部分文件的抓取 w4<1*u@${  
**FileSplitterFetch.java %fnL  
*/ 6%~ Z^>`N  
package NetFox; (e S4$$g  
v1<3y~'f  
M%5qx,JQY  
import java.io.*; nAG2!2_8  
import java.net.*; R2yiExw<  
( e6JI]tz{  
Eb{Zm<TP  
public class FileSplitterFetch extends Thread { Tn< <i  
uV`r_P  
5Jh=${  
String sURL; //File URL ='a[(C&Y  
long nStartPos; //File Snippet Start Position @v\Osp t=  
long nEndPos; //File Snippet End Position `WGT`A"  
int nThreadID; //Thread's ID x hBlv  
boolean bDownOver = false; //Downing is over pca `nN!  
boolean bStop = false; //Stop identical <43O,Kx'Su  
FileAccessI fileAccessI = null; //File Access interface "VR>nyG%  
.z4 fJx  
sxinA8  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r) ;U zd  
{ n=WwB(}q  
this.sURL = sURL; <SGO+1zt p  
this.nStartPos = nStart; O{SP4|0JV  
this.nEndPos = nEnd; <V0]~3  
nThreadID = id; '`&gSL.1a@  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w4P?2-kB  
} .w/w] Eq  
FJomUVR.  
rg64f'+Eug  
public void run() Y|FF ;[  
{ q}p&<k  
while(nStartPos < nEndPos && !bStop) q@8Jc[\d  
{ N]udZhkn  
6^y*A!xY  
xCGa3X  
try{ j\k|5 ="w-  
URL url = new URL(sURL); W5PNp%+KE  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9z6-HZG'~<  
httpConnection.setRequestProperty("User-Agent","NetFox");  u:JD  
String sProperty = "bytes="+nStartPos+"-"; P|HxD0c^u  
httpConnection.setRequestProperty("RANGE",sProperty); e=&,jg?K  
Utility.log(sProperty); 8Q ba4kgL  
88x_}M^Fnl  
Ndq/n21j  
InputStream input = httpConnection.getInputStream(); 1Kszpt(Ld  
//logResponseHead(httpConnection); d"o5uo  
rT7W_[&P  
WyciIO1  
byte[] b = new byte[1024]; lHQ:LI  
int nRead; `,a6su (?  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 67/JsL  
{ no_;^Ou?  
nStartPos += fileAccessI.write(b,0,nRead); Z> Jm  
//if(nThreadID == 1) .P(k |D&  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W|h~&O  
} dJxdrs  
G(gJt l  
m_YXTwwx  
Utility.log("Thread " + nThreadID + " is over!"); ~SUrbRaY>  
bDownOver = true; z#9Tg"8]  
//nPos = fileAccessI.write (b,0,nRead); }zC9;R(E  
} U|SF;T .  
catch(Exception e){e.printStackTrace ();} n'*4zxAA  
} 2q]y(kW+  
} )tYu3*'  
" E+V >V+  
Cge@A'2  
//打印回应的头信息 GPV=(}z  
public void logResponseHead(HttpURLConnection con) &iKy  
{ =`Ii ?xo  
for(int i=1;;i++) z7TMg^9 #  
{ Io_bS+  
String header=con.getHeaderFieldKey(i); 8'XAZSd(  
if(header!=null) z5.Uv/n\1  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v2eLH:6  
Utility.log(header+" : "+con.getHeaderField(header)); :jL>sGvBv  
else q[?xf3  
break; h [*/Tnr  
} `%S 35x9  
} "y~tAg  
fghw\\]3  
)&/ecx"2Q  
public void splitterStop() g{PEplk  
{ E$O-\)wY0  
bStop = true; -YvnX0j+  
} !UHWCJ< <w  
E;v#'  
xf2|9Tqt  
} 7m.#No>^  
yuP1*QJ%  
1N\/61+aA  
/* rfo7\'yk  
**FileAccess.java m&S *S_c  
*//文件访问(定位,写) suKr//_  
package NetFox; $?P5A E  
import java.io.*; [G!#y  
hp|.hN(kS]  
P^'TI[\L9  
public class FileAccessI implements Serializable{ :/A7Z<u,  
Ymvd3>_  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a+mrsyM  
RandomAccessFile oSavedFile;  iYaS  
long nPos; *Wj]e%  
N!~O~ Eo3  
 'ug:ic  
public FileAccessI() throws IOException deLLqdZa  
{ w'uB&z4'  
this("",0); 6W\G i>  
} q4MR9ig1E_  
{,NF'x4$  
[?>\]  
public FileAccessI(String sName,long nPos) throws IOException s5s'[<  
{ -v %n@8p  
oSavedFile = new RandomAccessFile(sName,"rw"); px${ "K<  
this.nPos = nPos; .9NYa|+0  
oSavedFile.seek(nPos); n2A ; `=  
} iW%~>`tT  
i(qZ#oN  
X'uQr+p^  
public synchronized int write(byte[] b,int nStart,int nLen) G)8v~=Bv  
{ T W#s)iDi  
int n = -1; `!(I Q&  
try{ J?#Xy9dz  
oSavedFile.write(b,nStart,nLen); MCO2(E-  
n = nLen; ,ZV>"'I:  
} ?lca#@f(  
catch(IOException e) AZ.$g?3w  
{ WAt= T3  
e.printStackTrace (); LvqWA}  
} )FpizoVq0  
a%nf )-}|  
dtj+ av G  
return n; {8* d{0l  
} @WCA 7DW!  
}]i.z:7+  
FG!2h&k  
} |:w)$i& *  
I>EEUQR/$H  
^UCH+C yl  
/* oGRd ;hsF  
**SiteInfoBean.java 6gs0Vm  
*/ 6Ki!j<  
package NetFox; [H[L};%=j  
KAJR.YNm  
5 ) q_Aro  
public class SiteInfoBean { ^c<8|lK L@  
r;^%D(  
j7BLMTF3v  
private String sSiteURL; //Site's URL VUi> ]v/e  
private String sFilePath; //Saved File's Path )+Y"4?z~  
private String sFileName; //Saved File's Name =PF2p'.o  
private int nSplitter; //Count of Splited Downloading File hd*GDjmRQ/  
B:Y F|k}T  
W{%X1::q$  
public SiteInfoBean() Vk> &  
{//nSplitter的缺省值为5 B*(BsXQLY  
//default value of nSplitter is 5 QWc,JCu  
this("","","",5); xa'^:H $X  
} $cW t^B'  
%*NED zy  
-7KoR}Ck!  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P;`Awp?  
{ jF-:e;-  
sSiteURL= sURL; &,P; 7R  
sFilePath = sPath; a&2UDl%K  
sFileName = sName; I_m3|VCa|t  
this.nSplitter = nSpiltter; c@2a)S8Y]  
G@KDRv  
7B<,nKd  
} : *XAQb0  
ypgM&"eR  
M1]}yTCd  
public String getSSiteURL() R< L =&I  
{ w4fQ~rcUIc  
return sSiteURL; hFo29oN  
} riL|B 3  
x6)qs-  
d>?C?F  
public void setSSiteURL(String value) 9Fy 'L#%  
{ Z3yy(D>*  
sSiteURL = value; #*q]^Is"  
} nG";?TT  
P!"{-m'  
Q*Y-@lZ  
public String getSFilePath() &09&;KJ  
{ ?nPG#Z|%  
return sFilePath; X}xf_3N "  
} 0 *;i]owV  
{cUGksz]}  
b}DC|?~M  
public void setSFilePath(String value) gW<6dP'v  
{ qyxd9Lk1  
sFilePath = value; Gy[anDE&  
} m_;fj~m  
soLW'8  
q9dplEe5  
public String getSFileName() Zs]n0iwM'@  
{ {sf ,(.W  
return sFileName; gxhdxSm=2  
} +HPcv u?1  
R`Fgne$4  
Zf1 uK(6X  
public void setSFileName(String value) *;)O'|  
{ ZH|q#< {l  
sFileName = value; 2{.g7bO  
} < =~=IZ)  
2WDe 34   
/* qx5$~  
public int getNSplitter() H[nco#  
{ tkH]_cH'w  
return nSplitter; g^Hf^%3xP  
} /@|iI<|  
UWnF2,<s;  
}AA">FF'y4  
public void setNSplitter(int nCount) %*szB$ [3  
{ X4 ] miUmh  
nSplitter = nCount; 4Z>gK(  
} Gh/nNwyu<  
} qFK.ULgP`  
ht*(@MCr<  
\i/HHP[%  
/* =%<, ^2o  
**Utility.java eM{u>n+`F0  
*/ "AZ|u#0P  
package NetFox; !qp$Xtf+  
7)]boW~Q  
\I:27:iAL  
public class Utility { P JATRJ1.  
Pn^`_  
nShXY6bA  
public Utility() pbEWnx_  
{ _}Qtx/Cg  
p5$}h,7  
[.^ol6  
} &9^4- 5]  
Pc*lHoVL  
//线程睡眠 p:TE##  
public static void sleep(int nSecond) }ymW};W  
{ Zj!,3{jX^  
try{ "5L?RkFi\  
Thread.sleep(nSecond); >t.Lc.  
} %'ah,2a%  
catch(Exception e) '5 Yzo^R;  
{ f*<Vq:N=\  
e.printStackTrace (); HA8A}d~  
} \#(1IC`as  
} SGSyO0O  
YTFU# F  
//日志 26g]_Igq  
public static void log(String sMsg) %-yzU/`JF  
{ ;  ?f+  
System.err.println(sMsg); F$DA/{.D  
} 4VZI]3K,  
, + G  
t$(#$Z,RS  
public static void log(int sMsg) CDM6o!ur3  
{ _\KFMe= PV  
System.err.println(sMsg); WM`3QJb  
} COsmVQ.  
} d_d&su E  
g kO^J{_@q  
~1D^C |%  
/* r) x  
**TestMethod.java W,NqevXo:  
*/ `X5!s  
package NetFox; jhm/ <=  
BW7AjtxQ&  
a51e~mg Z`  
public class TestMethod { F$)l8}  
2PYnzAsl  
;O% H]oN  
public TestMethod() \KnRQtlI  
{ ///xx/weblogic60b2_win.exe @JXpD8jn  
try{ O\.^H/  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %h@1lsm1+  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q@~g.AMCB  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'KA$^  
fileFetch.start(); 4?1Qe\A^  
} !nSa4U,$w<  
catch(Exception e){e.printStackTrace ();} 8j;Un]  
M i& ;1!bg  
]B,tCBt  
} >Xk42zvqn  
v']_)  
6&os`!  
public static void main(String[] args) `jGeS[FhR  
{ xcr2|  
new TestMethod(); qg& /!\  
} EjLq&QR.  
} a*y9@RC}  
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