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http断点续传简单实现(java)

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/* XE>w&  
**SiteFileFetch.java >D jJ*vM  
*/ +\doF  
package NetFox; F?z:[1(:  
import java.io.*; t$Bu<frQ  
import java.net.*; lfAiW;giJ  
oVTXn=cYDp  
xfF;u9$;  
public class SiteFileFetch extends Thread { `fuQ t4  
_/czH<   
gSa!zQN6  
SiteInfoBean siteInfoBean = null; //文件信息Bean Gx7bV}&PN  
long[] nStartPos; //开始位置 M }! qH.W  
long[] nEndPos; //结束位置 S:K$fFcJ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 /1v:eoF;  
long nFileLength; //文件长度 "38L ,PW0Z  
boolean bFirst = true; //是否第一次取文件 dWx@<(`OC  
boolean bStop = false; //停止标志 3(Ns1/;?,  
File tmpFile; //文件下载的临时信息 }[{9u#@#  
DataOutputStream output; //输出到文件的输出流 =H`yzGt  
?KB] /gT^  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) xnC:?d  
public SiteFileFetch(SiteInfoBean bean) throws IOException =9Vo[  
{ gg/ts]$  
siteInfoBean = bean; C2aA])7 D  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Q:j~ kutS|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); A^E 6)A=  
if(tmpFile.exists ()) ,(RpBTV  
{ '6kD6o_p1  
bFirst = false; f|=u{6  
read_nPos(); PqIskv+  
} *;(^)Sj4Q  
else fP[S.7F+No  
{ '`YZJ  
nStartPos = new long[bean.getNSplitter()]; jo?[M  
nEndPos = new long[bean.getNSplitter()]; gAh#H ?MM  
} gKY6S?  
l1#.r g  
V%{WH}  
JljCI@  
} =k*XGbU  
t 9t '9  
?(U a+*b  
public void run() q'/o=De  
{ 1{5t.  
//获得文件长度 oB%_yy+  
//分割文件 +0 }_X  
//实例FileSplitterFetch C(9"59>{]y  
//启动FileSplitterFetch线程 c3Gy1#f:#2  
//等待子线程返回 8{]nS8i  
try{ xFekSH7[F  
if(bFirst) !-N!Bt8;  
{ ^Zp  
nFileLength = getFileSize(); mo3A*|U  
if(nFileLength == -1) m[(_fOd  
{ BzzZ.AH~  
System.err.println("File Length is not known!"); MRw4?HqB  
} _Rb2jq(&0  
else if(nFileLength == -2) UM#.`  
{ TqL+^:cq  
System.err.println("File is not access!"); hkyO_ns  
} qp)Wt6 k?  
else NjT*5 .  
{ $_,-ES I  
for(int i=0;i<nStartPos.length;i++) *sZH3:  
{ L&y"oAp<  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); $qr6LIKGw  
} Qclq^|O0  
for(int i=0;i<nEndPos.length-1;i++) M| j=J{r  
{ 9gdK&/ulR  
nEndPos = nStartPos[i+1]; K9.Gjw  
} *Ti"8^`6  
nEndPos[nEndPos.length-1] = nFileLength; #qmsZHd}b  
} _'ebXrbZB  
} TTFs|T6`q  
oGB|k]6]|  
F81EZ/  
//启动子线程 $2}#):`  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xpO;V}M|  
for(int i=0;i<nStartPos.length;i++) !zx8I7e4  
{ /gl8w-6  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pqb`g@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), '2i !RT-  
nStartPos,nEndPos,i); H8[A*uYL  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UOf\pG  
fileSplitterFetch.start(); ypG*41  
} ~Gz9pBv1  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d"miPR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @y~kQ5k  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f+hHc8g  
nEndPos = " + nFileLength); PU,$YPrZ  
// fileSplitterFetch[nPos.length-1].start(); ls&H oJ7  
M-@X&b m,S  
A9 g%>  
//等待子线程结束 A]5];c  
//int count = 0; H\a"=&M  
//是否结束while循环 *9$SFe|&n:  
boolean breakWhile = false; wiZ  
;m#4Q6k)V?  
;aW k-  
while(!bStop) Vc;[0iB  
{ 5|*`} ;/y  
write_nPos(); oPr`SYB  
Utility.sleep(500); [%^sl>,7  
breakWhile = true; B+U:=591  
1n!:L!,`  
1u7D:h>#  
for(int i=0;i<nStartPos.length;i++) J](NCD  
{ `62v5d*>a  
if(!fileSplitterFetch.bDownOver) } v:YSG  
{ 1J/'R37lP  
breakWhile = false; !pw )sO~  
break; k:run2K  
} F c5t,P  
} @}g3\xLiK  
if(breakWhile) CAC4A   
break; 0jlM~H  
"%Y=+  
lMGO4U[z  
//count++; >bze0`}Z  
//if(count>4) q0VAkVHw4  
// siteStop(); *YeQC t-l  
} M=uT8JB  
iLuC_.'u=  
-i2rcH  
System.err.println("文件下载结束!"); } #H,oy;Dz  
} SK'h!Ye5Z  
catch(Exception e){e.printStackTrace ();} [M~tH *4"  
} KoNu{TJ  
W<pr Y  
}^Q:Q\  
//获得文件长度 Zyz#xMmM  
public long getFileSize() j@z IJ  
{ #Z2 'Y[@.  
int nFileLength = -1; ylZQwICk  
try{ A|r3c?q  
URL url = new URL(siteInfoBean.getSSiteURL()); T3z ovnR  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n >y,{"J{  
httpConnection.setRequestProperty("User-Agent","NetFox"); f_S$CFa@  
OA3J(4!"W  
PO"lY'W.U  
int responseCode=httpConnection.getResponseCode(); /o;L,mcx*  
if(responseCode>=400) ~k?rP}>0  
{ ?lsK?>uU  
processErrorCode(responseCode);  80@\e  
return -2; //-2 represent access is error e`qrafa  
} V )<>W_g  
B&a{,.m&q6  
gA(npsUHI  
String sHeader; f $Agcy  
H<_Tn$<zH.  
4<#ItQ(  
for(int i=1;;i++) vzg^tJ  
{ 8{G!OBxc\.  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +QFKaS<sn  
//Utility.log(in.readLine()); .pUB.l$)  
sHeader=httpConnection.getHeaderFieldKey(i); h(/? 81:  
if(sHeader!=null) ta)gOc)r R  
{ PuP"( M  
if(sHeader.equals("Content-Length")) x *I'Ar  
{ ]2@(^x'=  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9!n:hhJM  
break; ,zoHmV1Wd+  
} lm4A%4-db  
} L>14=Pr^(  
else M +OVqTsFU  
break; |M7C=z='  
} "rn  
} W]D YfR,  
catch(IOException e){e.printStackTrace ();} fYP,V0P  
catch(Exception e){e.printStackTrace ();} NRx 7S 9W  
$ Lstq_x+  
^s6~*n<fH  
Utility.log(nFileLength); h2zSOY{su  
aE07#  
PL= v,NB  
return nFileLength; pqO3(2F9  
} *,X)tZ6VX  
RDbNC v#  
7-B|B{]  
//保存下载信息(文件指针位置) %_E5B6xi{  
private void write_nPos() mHMsK}=~  
{ HAO-|=c4  
try{ Vl1.]'p_  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6h/!,j0:t_  
output.writeInt(nStartPos.length); 7RUztu\_  
for(int i=0;i<nStartPos.length;i++) t_Eivm-,B  
{ ,.P]5 lE  
// output.writeLong(nPos); aZ~e;}w.Zq  
output.writeLong(fileSplitterFetch.nStartPos); @-)S*+8  
output.writeLong(fileSplitterFetch.nEndPos); : _Y^o  
} G%~V b  
output.close(); l^R:W#*+U  
} 7{U[cG+a#  
catch(IOException e){e.printStackTrace ();} xCL)<8[R,}  
catch(Exception e){e.printStackTrace ();} |5;,]lbt  
} DH.`  
M %zf?>])  
-aJ(-Np$f  
//读取保存的下载信息(文件指针位置) =Jl\^u%H(x  
private void read_nPos() ;,U@zB;\%(  
{ puMVvo  
try{ bP$e1I3`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6'*6tS  
int nCount = input.readInt(); o Rk'I  
nStartPos = new long[nCount]; 5L6.7}B  
nEndPos = new long[nCount]; z]g#2xD2  
for(int i=0;i<nStartPos.length;i++) d >L8S L  
{ qX5]\nX&G  
nStartPos = input.readLong(); TCzz]?G]la  
nEndPos = input.readLong(); ; t7F%cDA  
} 1Mq"f 7X8  
input.close(); gm]q<~eMW  
} >7a ENKOg:  
catch(IOException e){e.printStackTrace ();} B_Wig2xH0  
catch(Exception e){e.printStackTrace ();} uu4! e{K  
} 7202N?a {  
,FYA*}[  
>*/ |t L  
private void processErrorCode(int nErrorCode) \l(}8;5}  
{ q@1A2L\Om  
System.err.println("Error Code : " + nErrorCode); Q >yj<DR  
} D3 +|Os)  
B7A.~' =  
`o_i+?E  
//停止文件下载 3 |e~YmZx  
public void siteStop() +:#g6(P]  
{ h Q Att  
bStop = true; 'lC=k7@x  
for(int i=0;i<nStartPos.length;i++) #/(L.5d[  
fileSplitterFetch.splitterStop(); Z^F>sUMR  
N<(rP1)`v  
ViOXmK"  
} U2_;  
} ZnbpIJ8cV  
//负责部分文件的抓取 L(y~ ,Kc  
**FileSplitterFetch.java ,9:v2=C_  
*/ P'5Lu  
package NetFox; -K^(L #G  
<1sUK4nQ,  
f:t5`c.  
import java.io.*; ciH TnC  
import java.net.*; 10dK%/6/O  
^y&2N  
) \cnz  
public class FileSplitterFetch extends Thread { ' wLW`GX.  
T2T?)_f /  
odeO(zuU  
String sURL; //File URL dZJU>o'BG  
long nStartPos; //File Snippet Start Position &6Wim<*  
long nEndPos; //File Snippet End Position 2zjY|g/  
int nThreadID; //Thread's ID [di&N!Ao  
boolean bDownOver = false; //Downing is over ^> d"D  
boolean bStop = false; //Stop identical =:RNpi,  
FileAccessI fileAccessI = null; //File Access interface )6he;+  
,l)AYu!q4F  
,(yaWd6  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -fz(]d  
{ H#`&!p  
this.sURL = sURL; ~r]$(V n  
this.nStartPos = nStart; 6`'KM/   
this.nEndPos = nEnd; xiQd[[(sM  
nThreadID = id; mc6W"  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .O4=[wE!U  
} na/,1iI<  
du=[r  
wlX K2D  
public void run() -uK@2} NZ  
{ TkjZI}]2  
while(nStartPos < nEndPos && !bStop) HtI>rj/\ x  
{ >3ASrM+>w  
52Q~` t7F  
(7P VfS>;  
try{ t9kqX(!  
URL url = new URL(sURL); QtqE&j  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'P >h2^z  
httpConnection.setRequestProperty("User-Agent","NetFox"); <d hBO  
String sProperty = "bytes="+nStartPos+"-"; *7/MeE6)i  
httpConnection.setRequestProperty("RANGE",sProperty); CY.i0  
Utility.log(sProperty); `>$l2,  
P?U}@U~9  
V^p XbDRl  
InputStream input = httpConnection.getInputStream(); 1A 9Gf  
//logResponseHead(httpConnection); 6?jSe<4x  
T ;JA.=I  
=Cr F(wVO"  
byte[] b = new byte[1024]; [;i3o?\_I  
int nRead; []eZO_o6j  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c"@,|wCUi  
{ V_7QWIdiy>  
nStartPos += fileAccessI.write(b,0,nRead); [ U?a %$G>  
//if(nThreadID == 1) /H[!v:U  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ig,v6lqhM  
} S QVyCxcX_  
`BZX\LPHm  
 w4p<q68  
Utility.log("Thread " + nThreadID + " is over!"); <q#/z&F!  
bDownOver = true; Q" an6ht|  
//nPos = fileAccessI.write (b,0,nRead); _:,U$W  
} (&Z`P  
catch(Exception e){e.printStackTrace ();} lvZ:Aw r  
} ) bGzsb1\  
} '@+a]kCMev  
S~LT Lv:>  
.9;wJ9Bw[  
//打印回应的头信息 \?.Tq24  
public void logResponseHead(HttpURLConnection con) 27KfT] =  
{ QZ51}i  
for(int i=1;;i++) 0?nm`9v6  
{ %phv<AW  
String header=con.getHeaderFieldKey(i); R+O[,UM^I~  
if(header!=null) #r_&Q`!eU  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *b0f)y3RV  
Utility.log(header+" : "+con.getHeaderField(header)); \;s mH;m  
else c,I|O' &k  
break; p#95Q  
} _n+./ B  
} kdry a  
"Aq-H g  
FWbA+{8  
public void splitterStop() z2lEHa?w  
{ *Q8d &$ ^  
bStop = true; l1qWl   
} Qm\VZ<6/5  
{~ngI<  
w oqP&8a  
} _ADK8a6%)  
,4wZ/r> d  
>@BvyZ)i  
/* S?5z  
**FileAccess.java .{1MM8 Q  
*//文件访问(定位,写) zV }-_u.  
package NetFox;  ? h$>7|  
import java.io.*; huau(s0um  
m{bw(+r  
g[P8  
public class FileAccessI implements Serializable{ S/ Y1NH  
.hCOi<wB  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;Vad| -  
RandomAccessFile oSavedFile; Z=Oo%lM6B  
long nPos; 24Y~x`W   
RJ%~=D  
@Kd lX>i  
public FileAccessI() throws IOException k.DDfuKN  
{ LV&tu7c  
this("",0); ^zv28Wq>  
} [Uezi1I  
 [;D4,@A  
o(. PxcD  
public FileAccessI(String sName,long nPos) throws IOException XY5I5H_U  
{ 3`&2 -  
oSavedFile = new RandomAccessFile(sName,"rw"); ]OoqU-q  
this.nPos = nPos; kg$<^:uX  
oSavedFile.seek(nPos); (d[)U<  
} 6M"]p  
'$M=H.  
Rp)82- .  
public synchronized int write(byte[] b,int nStart,int nLen) `n7z+  
{ n2R{$^JxO  
int n = -1; )#r]x1[Kn  
try{ tWi@_Rlx;  
oSavedFile.write(b,nStart,nLen); EeKEw Sg  
n = nLen; YSt']  
} iuq-M?1  
catch(IOException e) }@V(y9K  
{ v"L<{HN  
e.printStackTrace (); Cl]E rg  
} <Ja>  
Xb42R1  
"j9,3yJT  
return n; S"w$#"EJA  
} "!gd)^<e  
e.i5j^5u  
(?&X<=|"  
} J;+iW*E:  
LI?rz<H!D  
0vUX^<  
/* HW{osav9  
**SiteInfoBean.java QdG_zK>|e  
*/ [[?:,6I  
package NetFox; H;}V`}c<`  
u|=_!$8  
Ud:v3"1  
public class SiteInfoBean { &M ~*w~w`  
0W9,uC2:N  
&D uvy#J  
private String sSiteURL; //Site's URL ycRy! 0l  
private String sFilePath; //Saved File's Path y-{^L`%Mk  
private String sFileName; //Saved File's Name 1A">tgA1  
private int nSplitter; //Count of Splited Downloading File sW#6B+5_k  
NZ'S~Lr   
/_?Ly$>'  
public SiteInfoBean() xe|o( !(  
{//nSplitter的缺省值为5 Tul_/`An  
//default value of nSplitter is 5 VLN=9  
this("","","",5); 8\`]T%h  
} BM1uZJ0  
G1vWHa7n;f  
qp^O\>c  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Tv3Bej  
{ :p(3Ap2TY  
sSiteURL= sURL; Io{)@H"f  
sFilePath = sPath; q/?#+d  
sFileName = sName; ;_,=  
this.nSplitter = nSpiltter; I)]wi%  
%s%v|HDs  
U"A]b(54  
} M/ 0!B_(R  
'u{m37ZJ  
{$HW_\w  
public String getSSiteURL() 9PVM06   
{ $&='&q  
return sSiteURL; pcv(P  
} ^LE`Y>&m  
# h]m8  
{ o=4(RC  
public void setSSiteURL(String value) vL`wn=  
{ ^vLHs=<  
sSiteURL = value; "?EA G  
} @U_w:Q<9u  
ce/Rzid  
f[HhLAVGK`  
public String getSFilePath() 3lqR(Hh3  
{ k+{ -iPm{  
return sFilePath; '%yWz)P  
} ^TJn&k  
=4"D8 UaHr  
_y#t[|}w  
public void setSFilePath(String value) cj`g)cX|  
{ ((\s4-   
sFilePath = value; aIpDf|~  
} t(-noy)  
&7!&]kA+  
Ka&[ Oz<w  
public String getSFileName() AdesR-e$R  
{ %'nM!7w@I  
return sFileName; WLQm|C,  
} + O=wKsGD  
7JD jJQy  
5vj;lJKcd`  
public void setSFileName(String value) CDQ}C=4  
{ N0oBtGb  
sFileName = value; Ra}%:  
} ZWQrG'$?o8  
B\wH`5/KW  
?1K|.lr  
public int getNSplitter() fHCLsI  
{ {1;j1|CI  
return nSplitter; N W :_)1  
} UB }n=  
$-[V)]h  
Q"n*`#Yt'  
public void setNSplitter(int nCount) MU4/arXy  
{ Sg(fZ' -  
nSplitter = nCount; L!Iu\_{q  
} Q3vC^}Dmr  
} U8KB @E  
ce{(5IC  
i[/g&fx  
/* obKWnet  
**Utility.java T$5u+4>"  
*/ %Sr/'7 K  
package NetFox; :p0|4g  
3JVENn9  
^I=c]D]);  
public class Utility { (lq7 ct  
Z{s&myd  
#5-5N5-1  
public Utility() ="<5+G  
{ j}7as&  
s+&Ts|c#  
yBqv'Y  
} 3e4; '5q;  
P9= L?t.  
//线程睡眠 w DswK "T  
public static void sleep(int nSecond) S=H<5*]g  
{ xdb9oH  
try{ 7\m.xWX e  
Thread.sleep(nSecond); L1A0->t  
} Pw i6Ly`  
catch(Exception e) 7?a@i; E<  
{ ~L$B]\/A5  
e.printStackTrace (); ivg:`$a[  
} 8 #fzL7  
} Rj 2N+59rg  
}#}IR5`=E  
//日志 7Gb1[3  
public static void log(String sMsg) Q;{[U!\:  
{ BayO+,>K  
System.err.println(sMsg); 8}9|hT;  
} Z0*Lm+d9z  
8Q&.S)hrN  
.J:04t1  
public static void log(int sMsg) #RAez:BI  
{ "Y0:Y?Vz"  
System.err.println(sMsg); !R*%F  
} ,,1H#;j  
} q>:>f+4  
<Y~?G:v6+  
fDy Fkhc  
/* W:D'k^u  
**TestMethod.java Q- ( [3%  
*/ ]"bkB+I  
package NetFox; :Awnj!KNCc  
T \%{zz_(  
UB[tYZ  
public class TestMethod { [U+6Tj,  
o=i)s2   
6&/H XqP  
public TestMethod() cx%[hM09  
{ ///xx/weblogic60b2_win.exe lF-;h{   
try{ `H+~LVH  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i*3 4/  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7^$PauAv  
SiteFileFetch fileFetch = new SiteFileFetch(bean); H|8vW  
fileFetch.start(); #N%ATV  
} ]jo^P5\h>  
catch(Exception e){e.printStackTrace ();}  +C3IP  
7oY}=281  
! K? o H  
} i! G^=N  
q~*3Bk~  
YrAaL"20  
public static void main(String[] args) _nw=^zS  
{ !(\OT  
new TestMethod(); zTi %j$o  
} -$Bom  
} o6f^DG3*  
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