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http断点续传简单实现(java)

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/* 0al8%z9e@  
**SiteFileFetch.java 2DbM48\E  
*/ IB+)2`  
package NetFox; C2 ] x  
import java.io.*; >E3 lY/[  
import java.net.*; <<[hZ$.  
'U'#_mYG  
wam- =3W  
public class SiteFileFetch extends Thread { 86,$ I+  
uuMHD{}?}  
S0<m><|kl  
SiteInfoBean siteInfoBean = null; //文件信息Bean Vz,2_QJ  
long[] nStartPos; //开始位置 hu+% X.F4  
long[] nEndPos; //结束位置 _{5t/^w&!  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 15^5y RXC  
long nFileLength; //文件长度 CAD:ifV  
boolean bFirst = true; //是否第一次取文件 X@n\~[.B  
boolean bStop = false; //停止标志 AE"E($S`  
File tmpFile; //文件下载的临时信息 L/R ES  
DataOutputStream output; //输出到文件的输出流 @)YQiE$  
XUyoZl?  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) a \PvRW*I  
public SiteFileFetch(SiteInfoBean bean) throws IOException \7Fkeo+  
{ E5b JIC(  
siteInfoBean = bean; d@72z r  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); NJglONO  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");  !bi}9w  
if(tmpFile.exists ()) dnP3{!"b  
{ on q~wEr  
bFirst = false; cOr@dUSL  
read_nPos(); YQ+Kl[ec  
} `b{.K,  
else $q6'VLPo  
{ =':,oz^|  
nStartPos = new long[bean.getNSplitter()]; }@V ,v[&e  
nEndPos = new long[bean.getNSplitter()]; }w)`)N  
} U 0M>A  
HjFY >(e  
.{|AHW&0<  
!cWnQRIt_F  
} wCb%{iowH  
<C'S#5,2  
Ay Obaa5  
public void run() %Jpb&CEY  
{ =!`\=!y  
//获得文件长度 6/#5TdJA  
//分割文件 mJ%r2$/*  
//实例FileSplitterFetch Y%V|M0 0`  
//启动FileSplitterFetch线程 d">Ya !W  
//等待子线程返回 [n_H9$   
try{ Dg LSDKO!  
if(bFirst) Y{8L ~U:  
{ ^8V cm*  
nFileLength = getFileSize(); YTco;5/  
if(nFileLength == -1) ^<e"OV  
{ o\luE{H .?  
System.err.println("File Length is not known!"); H5N(MihT  
} dIo|i,-  
else if(nFileLength == -2) nAp7X-t  
{ "p\XaClpz  
System.err.println("File is not access!"); N3};M~\  
} adJoT-8P6  
else 2rw<]Ce  
{ Wsr #YNhx|  
for(int i=0;i<nStartPos.length;i++) W&>+~A  
{ pP'-}%  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); e XU;UO^  
} DT=!  
for(int i=0;i<nEndPos.length-1;i++) YJ5;a\QxN  
{ a`w)awb  
nEndPos = nStartPos[i+1]; Kup-O u,  
} /rNY;qXM  
nEndPos[nEndPos.length-1] = nFileLength; !HXdUAKu  
} QsmG(1=  
} L#e|t0'#  
.~5cNu'#m  
K6 ,5C0  
//启动子线程 Oed&B  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7#,+Q(2  
for(int i=0;i<nStartPos.length;i++) (WW,]#^  
{ a<V=C  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S)"5X)mq  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |7zm!^t$  
nStartPos,nEndPos,i); Oh:SH|=]#  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F|V co]"S1  
fileSplitterFetch.start(); OD"eB?  
} 55oLj.l^j  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KG#|Cq  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iR#jBqXD  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,gU9y wg  
nEndPos = " + nFileLength); ?.A6HrAPB  
// fileSplitterFetch[nPos.length-1].start(); 'ce9v@(0  
utwh"E&W  
<,0& Ox  
//等待子线程结束 tS2lex%  
//int count = 0; 8IC((  
//是否结束while循环 >t8eVMMa  
boolean breakWhile = false; r/Pg,si  
+V |]:{3W  
7$GP#V1r/  
while(!bStop) @fpxGMy&  
{ "`:#sF9S  
write_nPos(); qc\o>$-:`  
Utility.sleep(500); PyHE >C%  
breakWhile = true; !*%3um  
!9o8v0ZI  
)K2n!Fbd  
for(int i=0;i<nStartPos.length;i++) gr=ke #   
{ hJ:Hv.{`)W  
if(!fileSplitterFetch.bDownOver) p,D/ Pb8  
{ yB. 6U56  
breakWhile = false; McnP>n  
break; m$J'nA  
} rI]:| k  
} )KRO=~Y  
if(breakWhile) o7 !@WOeZ3  
break; l!iB -?'u  
kd\yHI9A  
Mdwh-Cis/  
//count++; lQ+-g#`  
//if(count>4) >5 5/@+^  
// siteStop(); Q)a*bPz  
} *rEW@06^\  
iCx'`^HnP  
Q}2w~Cn\S  
System.err.println("文件下载结束!"); f\(Kou$  
} jv0e&rt  
catch(Exception e){e.printStackTrace ();} >8NQ8i=]V1  
} >Ft jrEB  
`Ze fSmb  
0XozYyq  
//获得文件长度 V,M8RYOnC!  
public long getFileSize() _F3vC#  
{ Ar'5kPzY>  
int nFileLength = -1; GV[[[fu  
try{ d&'6l"${  
URL url = new URL(siteInfoBean.getSSiteURL()); @pko zE-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &(.ZHF  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;5=pBP.  
<b Ta88,)  
Vr0RdO  
int responseCode=httpConnection.getResponseCode(); x@k9]6/zs  
if(responseCode>=400) b`:Eo+p   
{ *pWswcV/  
processErrorCode(responseCode); !E7/:t4  
return -2; //-2 represent access is error Ta[}k/zW  
} d#z67Nl6  
"{0kg'fU  
ng 6G<hi  
String sHeader; TOuFFR  
W4YC5ZH{l  
"1#,d#Q$  
for(int i=1;;i++) 1%=,J'AH  
{ Aqm0|GlJ  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L"b5P2{c  
//Utility.log(in.readLine()); ?4~lA L1  
sHeader=httpConnection.getHeaderFieldKey(i); Kc{wv/6}T  
if(sHeader!=null) T@S+5(  
{ n+i}>3'A  
if(sHeader.equals("Content-Length")) H5aUZ=  
{ _88~uYG  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `H|g~7KD&  
break; I%s/h4x^B[  
} E|fPI u  
} G37_ `C  
else . }1!MK5  
break; BW*zj=N%  
} }gn0bCJy  
} <=`@`rm{  
catch(IOException e){e.printStackTrace ();} F% |(pHk  
catch(Exception e){e.printStackTrace ();} kR_[p._  
PRUGUHY  
C eg6 o &^  
Utility.log(nFileLength); u@|yw)  
#\M<6n{  
EagI)W!s[  
return nFileLength; fAm2ls7c  
} lk'RWy"pw  
=Vv{td  
& 3a+6!L[  
//保存下载信息(文件指针位置) l%:_#1?isf  
private void write_nPos() >pYgF =J  
{ /za,&7sf  
try{ ]Lh\[@#1f  
output = new DataOutputStream(new FileOutputStream(tmpFile)); WgL! @g  
output.writeInt(nStartPos.length); NdZ: 7  
for(int i=0;i<nStartPos.length;i++) r9U1O@c  
{ 9PBmBP ~  
// output.writeLong(nPos); a|>MueJ  
output.writeLong(fileSplitterFetch.nStartPos); AuCVpDH  
output.writeLong(fileSplitterFetch.nEndPos); aqN.5'2\  
} >w'6ZDA*X  
output.close(); n#R!`*[  
} Ea !j-Lbo  
catch(IOException e){e.printStackTrace ();} St3~Y{aI|  
catch(Exception e){e.printStackTrace ();} G@;aqe[dB  
} p[$I{F*a  
Z~R i%XG  
O//e0?]W  
//读取保存的下载信息(文件指针位置) #-`lLI:w0  
private void read_nPos() WZr~Pb9  
{ K XGs'D  
try{ g=%&p?1@E  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1Li@O[%X<  
int nCount = input.readInt(); v$cD!`+k  
nStartPos = new long[nCount]; ;Cy@TzO/|  
nEndPos = new long[nCount]; 3m^BYr*y^  
for(int i=0;i<nStartPos.length;i++) 'ZDclz9}  
{ L9.#/%I\  
nStartPos = input.readLong(); C+mU_g>  
nEndPos = input.readLong(); I5~DC  
} o?3R HP47  
input.close(); DjKjEZHgM  
} Z*)<E)  
catch(IOException e){e.printStackTrace ();} bODl q  
catch(Exception e){e.printStackTrace ();} uu:)jxi  
} y{N9.H2  
p%s D>1k  
JjmL6(*ui  
private void processErrorCode(int nErrorCode) ymzm x$o=  
{ S;NXOsSu  
System.err.println("Error Code : " + nErrorCode); 3%} Ma,  
} cm]]9z_<  
A>?fbY2n  
oxzNV&D[{`  
//停止文件下载 bm4W,  
public void siteStop() 1mX*0>  
{ 1 W0;YcT]  
bStop = true; x6t;=  
for(int i=0;i<nStartPos.length;i++) |^F-.Z  
fileSplitterFetch.splitterStop(); GXfVjC31z  
qkIU>b,B  
$o/>wgQY-  
} @2mP  
} &0g,Xkr  
//负责部分文件的抓取 ]VvJ1Xn0  
**FileSplitterFetch.java 1@WGbORc*  
*/ c;^J!e  
package NetFox; ^Toi_  
ff#-USK^R  
>=V+X"\Z  
import java.io.*; ZwMw g t  
import java.net.*; <-F"&LI{<  
pV7Gh`<y  
P5>CSWy%  
public class FileSplitterFetch extends Thread { TI>yi ^}  
tX251S  
1 XG-O  
String sURL; //File URL {UcIt LjY  
long nStartPos; //File Snippet Start Position Ps7%:|K]  
long nEndPos; //File Snippet End Position =CoT{LRQ_  
int nThreadID; //Thread's ID L,6Y=?  
boolean bDownOver = false; //Downing is over HhL%iy1  
boolean bStop = false; //Stop identical |=LkV"_v  
FileAccessI fileAccessI = null; //File Access interface FT~^$)8=  
4i,SiFKB  
aW"!bAdx`,  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException  zjA/Z(  
{ qj&)w9RLJE  
this.sURL = sURL; jO 55<s94  
this.nStartPos = nStart; +!v RU`  
this.nEndPos = nEnd; M2}<gRL*}J  
nThreadID = id; ZhsZy wM  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Nj0)/)<r+  
} aJ8pJ{,P  
rg,63r  
>v[(w1?rX  
public void run() ^mi4q[PM  
{ A-5 +#  
while(nStartPos < nEndPos && !bStop) +&OqJAu  
{ !qlGt)G3  
mB{{o}'<u  
5F"?]'*/  
try{ Z+"&{g  
URL url = new URL(sURL); vi8~j  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^>Y%L(>  
httpConnection.setRequestProperty("User-Agent","NetFox"); &r%*_pX  
String sProperty = "bytes="+nStartPos+"-"; 7g)3\C   
httpConnection.setRequestProperty("RANGE",sProperty); QCR-lxO1  
Utility.log(sProperty); +,Az\aT/%  
$VWzv4^:  
0>iFXw:fn  
InputStream input = httpConnection.getInputStream(); 3J T3;O  
//logResponseHead(httpConnection); U[b;#Y1X  
_m],(J=,z  
bSf(DSqx  
byte[] b = new byte[1024]; |l xy< C4V  
int nRead; |a{]P=<q  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `fZD%o3l  
{ 2HXKz7da  
nStartPos += fileAccessI.write(b,0,nRead); 9Yyg}l:  
//if(nThreadID == 1) aLi_Hrb9  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N;'HR)  
} gE&W6z0fJ  
hX m} d\  
,dx)rZ*  
Utility.log("Thread " + nThreadID + " is over!"); m>ycN  
bDownOver = true; s&hA  
//nPos = fileAccessI.write (b,0,nRead); S |>$0P4W(  
} P/Kit?kngS  
catch(Exception e){e.printStackTrace ();} hFMst%:y$  
} </gp3WQ.  
} AwU c{h l<  
\oX8/-0f  
R:<@+z^A[  
//打印回应的头信息 PuCDsojclh  
public void logResponseHead(HttpURLConnection con) 4|N\Q=,  
{ o^Ysp&#p  
for(int i=1;;i++) v Q"s  
{ `8;,&<U'`  
String header=con.getHeaderFieldKey(i); hF"g 91P  
if(header!=null) QO{=Wi-  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !y-2#  
Utility.log(header+" : "+con.getHeaderField(header)); 4;RCPC  
else "F$o!Vk  
break; [fi'=Cb  
} `uh@iD'KI  
} cEc,eq|  
F,M"/hnPT  
P4j8`}&/  
public void splitterStop() ,6;xr'[o*  
{ }b+QYSt  
bStop = true; #we>75l{+R  
} vo ;F;  
RR!!hY3 K  
]<T8ZA_Y;  
} l(,;wAH  
;{f??G  
ZuvPDW%  
/* EB5_;  
**FileAccess.java Hpi%9SAM  
*//文件访问(定位,写) `n`"g<K)Q  
package NetFox; 'd #\7J>d  
import java.io.*; _/}Hqh  
;Q=GJ5`B  
1N9< d,  
public class FileAccessI implements Serializable{ u:$x6/t  
j- YJ."  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a4( ?]ND~6  
RandomAccessFile oSavedFile; ]}[Yf  
long nPos; q|o |/O-{  
Y/,$Y]%g  
b"M`@';+  
public FileAccessI() throws IOException eh:}X}c=J]  
{ *Z`XG_s5  
this("",0); eKVALUw  
} w,Zx5bBg%  
0<@KDlF  
jD/7/G*  
public FileAccessI(String sName,long nPos) throws IOException XDkS ^9  
{ M6]0Y@@>  
oSavedFile = new RandomAccessFile(sName,"rw"); 6 W;?8Z_1  
this.nPos = nPos; bugFl>  
oSavedFile.seek(nPos); %,,`N I{  
} ;wXY3|@  
3XwU6M$5g  
^'&iYV  
public synchronized int write(byte[] b,int nStart,int nLen) =r@gJw:B  
{ a1G9wC:e  
int n = -1; *i?rJH  
try{ |vfujzRZ  
oSavedFile.write(b,nStart,nLen); +z|UpI  
n = nLen; jefNiEE[  
} r|^lt7\  
catch(IOException e) 8nIMZV  
{ ^+.t-3|U  
e.printStackTrace (); OyJsz]b} M  
}  .3a:n\tY  
.6#cDrK  
],\sRQbv&  
return n; IAP/G5'Q  
} C[xJU6z  
1t~FW-:  
[O7w =  
} {b'}:aMc  
hG3m7ht  
A{z>D`d  
/* sK@Y!oF}\  
**SiteInfoBean.java _k_>aG23  
*/ 4YDT%_h0  
package NetFox; }UKgF.  
WVS$O99Y  
LBmM{Gu  
public class SiteInfoBean { cX %:  
(@)2PO /  
q]"2hLq  
private String sSiteURL; //Site's URL D[89*@v  
private String sFilePath; //Saved File's Path ZT) !8  
private String sFileName; //Saved File's Name Cf0|Z  
private int nSplitter; //Count of Splited Downloading File *$i;o3  
HKTeqH_:  
7q%|4Z-~  
public SiteInfoBean() ^^7L"je]g  
{//nSplitter的缺省值为5 euV$2Fg  
//default value of nSplitter is 5 @s%X  
this("","","",5); i}PK $sa#c  
} L#`2.nU  
EI1W .V>@  
[)#u<lZ<~  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /Jxq 3D)v  
{ m$fQ`XzU  
sSiteURL= sURL; h@*lWi2K7  
sFilePath = sPath; qDnCn H  
sFileName = sName; *.," N}  
this.nSplitter = nSpiltter; O87"[c`>  
{ p1lae  
v:r D3=M-  
} 6exI_3A4jh  
<nDNiM#  
}#yU'#|d  
public String getSSiteURL() C=N! z  
{ "^;#f+0  
return sSiteURL; P<%v +O  
} -xJX_6}A  
iv:,fkwG  
{(rf/:X!p  
public void setSSiteURL(String value) X*pZNz&E  
{  T/[f5?p  
sSiteURL = value; 7\IL  
} j~Q}F|i8  
A LXUaE.  
Q  |  
public String getSFilePath() b,#`n  
{ 8y$5oD6g9  
return sFilePath; m</]D WJ  
} }>2t&+v+  
gaQ[3g  
NW z9C=y  
public void setSFilePath(String value) N 0+hejz  
{ b -PSm=`  
sFilePath = value; j!YNg*H  
} O!;H}{[dg  
\B_i$<Sz  
zhNQuK,L  
public String getSFileName() ?-e7e %  
{ SOVj Eo4'3  
return sFileName; }N?g|  
} wHx}U M"  
:^ n*V6.4  
'X9AG6K1  
public void setSFileName(String value) lM>.@:  
{ :-z&Y492  
sFileName = value; K[kds`  
} H4t)+(:D'  
Zr=ib  
7 0_}S*T  
public int getNSplitter() ^f9>l;Lb  
{ p"2m90IO  
return nSplitter; Cl,9yU)1n  
} elu=9d];@  
0; 7#ji  
`|nH1sHFq  
public void setNSplitter(int nCount) `%e|$pK  
{ ;AKwx|I$g  
nSplitter = nCount; Hb+X}7c$  
} E Zi&]  
} G~"z_ (  
u$C\E<G^  
h\(B#SN  
/* 6 Ew@L<v  
**Utility.java RT,:hH  
*/ a"x}b  
package NetFox; bl=ku<}@  
GMl"{ Oxo&  
H<g 1m  
public class Utility { (~JwLe@a  
rvwa!YY}  
["u#{>(X  
public Utility() Lbcy:E*g  
{ Zae.MO^C!  
uQnT[\k?  
H9U .lb  
} {Ur7# h5  
@Gt`Ds9=  
//线程睡眠 V@[rf<,  
public static void sleep(int nSecond) m^<p8KZ  
{ :5J_5,?;`  
try{ p}uncIod  
Thread.sleep(nSecond); pr_>b`p6  
} 28a$NP\KW  
catch(Exception e) sf$o(^P9\A  
{ #AShbl jm+  
e.printStackTrace (); \Wr,<Y  
} }9^@5!qX  
} wjrG7*_Y4v  
M%I@<~wl  
//日志 Xw t`(h[u  
public static void log(String sMsg) M*w'1fT  
{ Jd_;@(Eg=  
System.err.println(sMsg); ,!Q]q^{C:W  
} Huc|6~X  
)hBE11,PB  
cL G6(<L  
public static void log(int sMsg) rh66_eV  
{ E;9>ePd@  
System.err.println(sMsg); k[ %aCGo  
} lNz]H iD  
} 6Z?Su(s(5  
RbEKP(uw  
3#c3IZ-;  
/* YHB9mZi  
**TestMethod.java 1'JD=  
*/ r{_>ldjq  
package NetFox; E8ta|D  
nn+_TMu  
zU&L.+   
public class TestMethod { {e"dm5  
(5a1P;_Y  
 .t =  
public TestMethod() ; b*i3*!g  
{ ///xx/weblogic60b2_win.exe Y%@hbUc}x9  
try{ eVJ^\z:4  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @}&_Dvf  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ml0*1Dw  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z.1> kZ  
fileFetch.start(); 6@V~0DG  
} v7,$7@$:\  
catch(Exception e){e.printStackTrace ();} XogVpkA  
MjD75hIZ  
l$XPIC~H  
} Rko M~`CT  
XKS8K4"  
2' ] KTHm  
public static void main(String[] args) <CZgQ\Mt  
{ , jU5|2  
new TestMethod(); e2cP *J  
} 6;iJ*2f5V  
} `XKVr  
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