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http断点续传简单实现(java)

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/* wnokP  
**SiteFileFetch.java 8X,6U_>#a  
*/ ~pRgTXbz  
package NetFox; #SHeK 4  
import java.io.*; R xMsP;be  
import java.net.*; *)Qv;'U=rn  
}qiZ%cT.G  
%XG m\p  
public class SiteFileFetch extends Thread { 5)RZJrN]  
309 pl  
O6hzOyNX@  
SiteInfoBean siteInfoBean = null; //文件信息Bean /xk7Z q  
long[] nStartPos; //开始位置 RE;A 0E_3  
long[] nEndPos; //结束位置 " #iJ/vy  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 _p*9LsN$L  
long nFileLength; //文件长度 =IC.FT}  
boolean bFirst = true; //是否第一次取文件 mITB\,,G  
boolean bStop = false; //停止标志 @PvO;]]%  
File tmpFile; //文件下载的临时信息 o^@"eG$,  
DataOutputStream output; //输出到文件的输出流 L~6%Fi&n4  
\C3I6Qx  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) (  zo7h  
public SiteFileFetch(SiteInfoBean bean) throws IOException i=EOk}R  
{ _Q5mPBO  
siteInfoBean = bean; 1(o\GI3:  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 13s/m&  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); H.ZIRt !RB  
if(tmpFile.exists ()) _= v4Iz0  
{ R])Eg&  
bFirst = false; AT"gRCU$4  
read_nPos(); mw 28E\U  
} Wi&v?nm  
else XR+ SjCA  
{ 0VNLhM(LM  
nStartPos = new long[bean.getNSplitter()]; !rUP&DA  
nEndPos = new long[bean.getNSplitter()]; l53i {o  
} iqDyE*a  
}Ja-0v)Wf  
efQ8jO  
@)U.Dbm  
} 5%Qxx\q  
*2zp>(%  
BmX'%5ho  
public void run() MLWHO$C~T  
{ N1~bp?$1  
//获得文件长度 ^ j\LB23  
//分割文件 }emUpju<C  
//实例FileSplitterFetch 7_\sx7h{3  
//启动FileSplitterFetch线程 z)3TB&;  
//等待子线程返回 1q7&WG  
try{ 7S{qo&j'  
if(bFirst) L"bJ#0m  
{ fa/S!%}fO  
nFileLength = getFileSize();  \(\a=  
if(nFileLength == -1) O@Aazc5K  
{ q| D5 A|)  
System.err.println("File Length is not known!"); XKjrS 9:  
} Ljy797{f  
else if(nFileLength == -2) *E/Bfp1LIe  
{ [9">}l  
System.err.println("File is not access!"); LIID(s!bX  
} >G5aFk  
else yvB]rz} i  
{ K3!3[dR*  
for(int i=0;i<nStartPos.length;i++) @Go_5X(  
{ :TQp,CEa  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Ixxs(  
} Z 8rD9 k$6  
for(int i=0;i<nEndPos.length-1;i++) *I]]Ogpq=  
{ H+[?{+"#@l  
nEndPos = nStartPos[i+1]; 1 (<n^\J(  
} H~j@n!)  
nEndPos[nEndPos.length-1] = nFileLength; o+1 (N#?m9  
} M/<ypJ  
} jR/Gd01)  
9lYKG ^#D  
{ W,5]-  
//启动子线程 & BPYlfB1  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d1D f`  
for(int i=0;i<nStartPos.length;i++) << 6 GE  
{ Cf[tNq  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A^OwT#  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c]9gf\WW  
nStartPos,nEndPos,i); mo| D  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5T;LWS  
fileSplitterFetch.start(); eGEwXza 4  
} Jh\KVmfXN  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rRe5Q  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f-F=!^.  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +VUkV-kP  
nEndPos = " + nFileLength); {lds?AuK  
// fileSplitterFetch[nPos.length-1].start(); V8n { k'  
,XT,t[w  
X?_rD'3  
//等待子线程结束 WzzA:X  
//int count = 0; \ja6g  
//是否结束while循环 ..`c# O&  
boolean breakWhile = false; .\XRkr'-  
tyR?A>F4  
Ub3$`  
while(!bStop) KtQs uL%  
{ IO\1nB$0nb  
write_nPos(); KTm^}')C8  
Utility.sleep(500); ^OV; P[  
breakWhile = true; P'<i3#;7X  
,l>w9?0Z  
E'WXi!>7p  
for(int i=0;i<nStartPos.length;i++)  kORWj<  
{ /!Rva"  
if(!fileSplitterFetch.bDownOver) x@  =p  
{ >fC&bab  
breakWhile = false; ']nIa7  
break; TQn!MUj/^  
} 5=TgOS]R  
} XVs]Y'* x  
if(breakWhile) tb&?BCp  
break; hCQOwk#  
(:bf m  
/4r2B. 91O  
//count++; {vD$odi  
//if(count>4) }_lG2#Ll5  
// siteStop(); ei= 4u'  
} j3sz"(  
 7UBDd1  
)w].m  
System.err.println("文件下载结束!"); s@L ;3WdO  
} #*A&jo'E  
catch(Exception e){e.printStackTrace ();} Nn_fhc>  
} WDw<kX6p  
2? E;(]dQ  
1| sem(t  
//获得文件长度 n{QyqI  
public long getFileSize() MXSD8]je  
{ g (&cq  
int nFileLength = -1; NO*, }aeG  
try{ :a*>PMTn  
URL url = new URL(siteInfoBean.getSSiteURL()); "Da 1BuX\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T, #-: }  
httpConnection.setRequestProperty("User-Agent","NetFox"); *8)?ZZMM  
C1-U2@  
iF`_-t/k  
int responseCode=httpConnection.getResponseCode(); NCk-[I?R  
if(responseCode>=400) ,3?=W/Um4  
{ "r6qFxY  
processErrorCode(responseCode); mu B Y  
return -2; //-2 represent access is error XoyxS:=>|[  
} g=td*S  
M{L<aYe  
Q h@Q6  
String sHeader; 7#)k-S!B  
QbdXt%gZe  
dg|+?M^9`  
for(int i=1;;i++) +Ug &  
{ x;[)#>.'  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ( %7V  
//Utility.log(in.readLine()); ?h`,@~6u  
sHeader=httpConnection.getHeaderFieldKey(i); >9w^C1"  
if(sHeader!=null) !hHe`  
{ ^6Aa^|  
if(sHeader.equals("Content-Length")) 8g=O0Gb  
{ S*Ea" vBA  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2[Bbdg[O  
break; ,.Ofv):=  
} E]q>ggeNH  
} `6rLd>=R  
else 0/~p1SSun  
break; Cx;it/8+  
} A6szTX#0  
} TY]0aw2]|7  
catch(IOException e){e.printStackTrace ();} jO"/5 x26  
catch(Exception e){e.printStackTrace ();} +/&rO,Ql  
@C-dCC?  
}<G a e5  
Utility.log(nFileLength); (lwV(M  
kg Bkwp  
I e!KIU  
return nFileLength; O[Z$~  
} 1<9d[N*  
moM'RO,M  
K14.!m  
//保存下载信息(文件指针位置) :/6:&7s  
private void write_nPos() p cD}SY  
{ L@MCB-@V  
try{ lsV>sW4]Z  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Gh_5$@ hF  
output.writeInt(nStartPos.length); t_^cqEr  
for(int i=0;i<nStartPos.length;i++) &# fPJc  
{ Wda?$3!^q  
// output.writeLong(nPos); @%g:'^/  
output.writeLong(fileSplitterFetch.nStartPos); _Nh])p-  
output.writeLong(fileSplitterFetch.nEndPos); ${Lrj}93  
} ~/4j&IG  
output.close(); ~JZLWTEe  
} eZ) |m  
catch(IOException e){e.printStackTrace ();} O#tmB?n*  
catch(Exception e){e.printStackTrace ();} tln}jpCw  
} <c@dE  
4PSbr$  
TFbc@rfB  
//读取保存的下载信息(文件指针位置) k&yBB%g  
private void read_nPos() a\-5tYo`u  
{ PM*lnd#J  
try{ R?:K\  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h9S f  
int nCount = input.readInt(); (6[<+j&.  
nStartPos = new long[nCount]; '1!%yKc0  
nEndPos = new long[nCount]; S%p,.0_  
for(int i=0;i<nStartPos.length;i++) ^p4`o>  
{ x^3K=l;N  
nStartPos = input.readLong(); }f> 81[^  
nEndPos = input.readLong(); qUe2(/TQu  
} <mLU-'c@  
input.close(); v-$X1s  
} 0lt1/PEKx2  
catch(IOException e){e.printStackTrace ();} \ bNDeA&l  
catch(Exception e){e.printStackTrace ();} z V $Z@o  
} AJ 0Bb7  
Xj?LU7  
d}E6d||A  
private void processErrorCode(int nErrorCode) $xvwnbq#y  
{ -XECYwTh  
System.err.println("Error Code : " + nErrorCode); @bkSA  
} k;umLyz  
 K0*er  
6mZpyt  
//停止文件下载 x=JZ"|TE  
public void siteStop() F[ ^ p~u{  
{ *[nS*D\:  
bStop = true; bN*zx)f  
for(int i=0;i<nStartPos.length;i++) } 2y"F@{T  
fileSplitterFetch.splitterStop(); 7B _Wz9y  
09Oe-Bg  
/\jRr7 Cd  
} v]drDVJ   
} "gpfD-BX  
//负责部分文件的抓取 N*w{NB7L  
**FileSplitterFetch.java Gd&G*x  
*/ I~ SFY>s  
package NetFox; 1\f8-:C  
.:['&; k  
0} \;R5a<  
import java.io.*; 1 xrmmK  
import java.net.*; #z}IW(u<  
c_?!V  
TGPdi5Eq  
public class FileSplitterFetch extends Thread { iaJN~m\ M  
_#UhXXD  
z<"\I60Fe  
String sURL; //File URL ]N'4q}<5o  
long nStartPos; //File Snippet Start Position kD+B8TrW  
long nEndPos; //File Snippet End Position XK l3B=h  
int nThreadID; //Thread's ID A- hWg;  
boolean bDownOver = false; //Downing is over Th])jQ*  
boolean bStop = false; //Stop identical imS&N.*3m  
FileAccessI fileAccessI = null; //File Access interface MM+nE_9lV  
53 ^1;  
Qa16x<Xlm  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <CP't[  
{ >>7m'-k%D  
this.sURL = sURL; $_Lcw"xO  
this.nStartPos = nStart; \4q1<j  
this.nEndPos = nEnd; fwyz|>H_Y(  
nThreadID = id; j"+R*H(#  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n]JfdI  
} +>h'^/rAE  
=dC5q{  
ET]`  
public void run() nG5:H.)  
{ Se5jxV  
while(nStartPos < nEndPos && !bStop) 1lUY27MF  
{ "6'# L,  
U}`HN*Q.q  
DOo34l6#  
try{ F[|aDj@q e  
URL url = new URL(sURL); |w^nCsv  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0w l31k{  
httpConnection.setRequestProperty("User-Agent","NetFox"); v/Ei0}e6~  
String sProperty = "bytes="+nStartPos+"-"; !U+XIr  
httpConnection.setRequestProperty("RANGE",sProperty); i3y>@$fRL\  
Utility.log(sProperty); 'v3> "b  
ZYW=#df R  
b~;+E#[*  
InputStream input = httpConnection.getInputStream(); a U*cwR  
//logResponseHead(httpConnection); Yyh X%S%  
;fDs9=3#  
[.iz<Yh  
byte[] b = new byte[1024]; oxm3R8 S  
int nRead; hz+x)M`Y  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OGO4~Up  
{ $5l=&  
nStartPos += fileAccessI.write(b,0,nRead); T%:W6fH7  
//if(nThreadID == 1) <N;HB&mr  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {Uu|NA87Cd  
} V-iY2YiR  
{@[z-)N7\,  
Z4Qq#iHZR  
Utility.log("Thread " + nThreadID + " is over!"); xBcE>^{1.  
bDownOver = true; X6@G)68  
//nPos = fileAccessI.write (b,0,nRead); Ik|nL#JH]  
} E>SLR8!C v  
catch(Exception e){e.printStackTrace ();} PM%Gsy]q  
} *9Nq^+  
} Yf(QU`w_  
Go_~8w0<  
)Wm:Ilq  
//打印回应的头信息 DbkKmv&  
public void logResponseHead(HttpURLConnection con) rfMzHY}%  
{ MY}B)`yx=  
for(int i=1;;i++) _gF )aE  
{ Dx27s  
String header=con.getHeaderFieldKey(i); f?A*g$v  
if(header!=null) 4jl-?  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ik4U+'z6  
Utility.log(header+" : "+con.getHeaderField(header)); &<sDbN S  
else j!P]xl0vOZ  
break; J;g+  
} tcf>9YsOr  
} t|aBe7t7  
#4*~ 4/  
vN%SN>=L<  
public void splitterStop() ceR zHq=  
{ Ol'Ct'_k,"  
bStop = true; r6`v-TY(/  
} poYO  
<OEu 4,~:  
?8Hr 9  
} !8U\GR `  
Ytnk^/Z1L  
AA um1xl  
/* Rx 4 ;X  
**FileAccess.java *1KrI9i  
*//文件访问(定位,写) Og`w~!\  
package NetFox; =)3tVH&  
import java.io.*; 3X&}{M:Qo  
QuJ)WaJkC  
$;dSM<r  
public class FileAccessI implements Serializable{ ]I#yS=;  
Tn qspS2;R  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Hinz6k6!  
RandomAccessFile oSavedFile; viT/$7`AI  
long nPos; 8I'c83w  
<O cD[5  
jR#g>MDKB  
public FileAccessI() throws IOException O#E]a<N`  
{ /K"koV;  
this("",0); : YU_ \EV  
} Xj&fWu A  
--S2lN/:T  
z5v)~+"1  
public FileAccessI(String sName,long nPos) throws IOException 7N / v  
{ Nj_h+=UE!  
oSavedFile = new RandomAccessFile(sName,"rw"); Z`23z( +  
this.nPos = nPos; 54w..8'  
oSavedFile.seek(nPos); wYJ.F  
} dhW)<  
9 BPucXK  
#AzZ4<;7  
public synchronized int write(byte[] b,int nStart,int nLen) 2#:h.8  
{ 7W6tz\Y  
int n = -1; DDT)l+:XP  
try{ $e7dE$eH  
oSavedFile.write(b,nStart,nLen); !PI& y  
n = nLen; eEkF Zx  
} EC2KK)=n}  
catch(IOException e) s HSZIkB-r  
{ {mK=Vig  
e.printStackTrace (); ?A /+DRQ(  
} wG4=[d  
QcGyuS.B  
V_?5cwZ  
return n; :;S]jNy}j)  
} YT6<1-E#  
%SL'X`j  
cbD&tsF  
} N*N@wJy:5  
@JS O=8  
cWSiJr):r  
/* ]VY}VALZ  
**SiteInfoBean.java : uglv6  
*/ C#`VVtei  
package NetFox; #y"E hwF  
Re**)3#gn  
B(x i  
public class SiteInfoBean { ]?p&sI4  
G%w hOIFRq  
4~8++b1/;  
private String sSiteURL; //Site's URL .V9/0  
private String sFilePath; //Saved File's Path j()<.h;'  
private String sFileName; //Saved File's Name +(*S@V$c  
private int nSplitter; //Count of Splited Downloading File L\--h`~YU  
&{?*aK&%3l  
Cvr?%+)$M  
public SiteInfoBean() JW;DA E<  
{//nSplitter的缺省值为5 ,lLkAd?q  
//default value of nSplitter is 5 4i>sOP3 B  
this("","","",5); K'EGm #I  
} )2KQZMtgm]  
BD+V{x}P  
KPI c?|o/6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z{w!yMp"  
{ /l-lkG5  
sSiteURL= sURL; p9ligs7V'  
sFilePath = sPath; ?'_E$  
sFileName = sName; =^m,|j|d>4  
this.nSplitter = nSpiltter; &o>ctf.x  
B>}=x4-8  
:gMcl"t--  
} Mvq5s+.  
sf\p>gb  
47b=>D8  
public String getSSiteURL() g/&`NlD  
{ 6\ g-KO  
return sSiteURL; m0+X 109  
} :|3n`,  
SnsOuC5Ah  
_Gv[ D  
public void setSSiteURL(String value) 7jIye8Zi8  
{ F3$@6J8<[z  
sSiteURL = value; $gU6=vN1#  
} }=CL/JHz  
?z>7&  
E?1"&D m  
public String getSFilePath() kXGJZ$  
{ y%A!|aBu  
return sFilePath; 1Uzsw  
} >6ul\xMU  
v|:2U8YREf  
]RgLTqv4x  
public void setSFilePath(String value) WV]%llj^  
{ ]]~tFdh  
sFilePath = value; E^z\b *  
} E_-3G<rt  
>h+[#3vD  
K]4XD1n7  
public String getSFileName() V3 j1M?>  
{ ns|)VX   
return sFileName; )&R^J;W$M1  
} ;Z%PBMa  
\~|+*^e)  
qP6 YnJWl  
public void setSFileName(String value) bi`{ k\3A  
{ |F _ Z  
sFileName = value; \8v{9Yb  
} &VG|*&M  
*"4d6  
dLb9p"EE#  
public int getNSplitter() \mRRx#-r%  
{ Y0`@$d&n  
return nSplitter; nA:\G":\y  
} GRV#f06  
0?hJ!IT;q7  
=\;yxl  
public void setNSplitter(int nCount) Q@B--Omfh  
{ 9aYDi)  
nSplitter = nCount; :<$B o  
} y{CyjYpz^  
} _&!%yW@  
<i9pJGW  
h/u>F$}c  
/* NjT#p8d X  
**Utility.java ts BPQ 8Ne  
*/ "RPX_  
package NetFox; Hgs=qH  
z8W@N8IqC  
KUs\7Sb  
public class Utility { 3KFw0(S/  
qI-q%]l  
m/W0vPM 1  
public Utility() |3\$\qa  
{ 7O6VnKl  
Z|&Y1k-h  
bo^d!/ ;  
} ;4DqtR"7Y  
|BrD:+  
//线程睡眠 L`E^BuP/  
public static void sleep(int nSecond) V_Owi5h  
{ S}zh0`+d'Z  
try{ =/xTUI4  
Thread.sleep(nSecond); {oIv%U9  
} )U4h?J  
catch(Exception e) Q}# 5mf&cD  
{ -oGJPl{r  
e.printStackTrace (); 2w>l nJ-  
} *Jd,8B/hC  
} <YU+W"jQT  
dxm_AUM  
//日志 1QHCX*_  
public static void log(String sMsg) }2qmL$  
{ V'vDXzk\  
System.err.println(sMsg); B/#tR^R  
}  q0Rd^c  
OE,uw2uaT  
!_{2\ &  
public static void log(int sMsg) 4}nsW}jCc  
{ utk'joo  
System.err.println(sMsg); Vg1! u+`<  
} _ PC}`Y'&  
} =Rnx!E  
/+pPcK  
C4V#qhj  
/* Jz(!eTVs  
**TestMethod.java =\v./Q-  
*/ [H#*#v  
package NetFox; T*"15ppfk  
 4{2)ZI#  
" bHeNWZ  
public class TestMethod { Wj N0KA  
o* q F"xG  
SZ+<0Y |  
public TestMethod() W?W vT` T{  
{ ///xx/weblogic60b2_win.exe BaSNr6 YW  
try{ I W_:nm6  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [E_+fT  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N_jCx*.G  
SiteFileFetch fileFetch = new SiteFileFetch(bean); r Ntc{{3_  
fileFetch.start(); {bF95Hs-  
} m#[tY >Q[b  
catch(Exception e){e.printStackTrace ();} ;1Kxqp z_i  
IT \Pj_  
oYWcX9R  
} [.e Y xZ{=  
:sT\-MpQvn  
W!a~ #R/r-  
public static void main(String[] args) i?^C c\gH  
{ RZykwD(  
new TestMethod(); g=?KpI-pn0  
} USVM' ~p I  
} :P$I;YY=A  
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