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http断点续传简单实现(java)

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/* `]i []|  
**SiteFileFetch.java 5B4Ssrs5W~  
*/ p3(2?UO!  
package NetFox; R2<s0l  
import java.io.*; w@-M{?R  
import java.net.*; xHA0gZf  
Fc6iQ  
L|j%S  
public class SiteFileFetch extends Thread { 3=mr "&]r:  
A7Po 3n%Q  
vB\]u.  
SiteInfoBean siteInfoBean = null; //文件信息Bean -NJ!g/ >mM  
long[] nStartPos; //开始位置 7[pBUDA  
long[] nEndPos; //结束位置 YHXLv#8  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 nz]&a1"&  
long nFileLength; //文件长度 0#_'o ,  
boolean bFirst = true; //是否第一次取文件 QzvHm1,@  
boolean bStop = false; //停止标志 oUZoj2G1  
File tmpFile; //文件下载的临时信息 q5DEw&UZJ  
DataOutputStream output; //输出到文件的输出流 H`9Uf)  
~f\G68c  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) O+q/4  
public SiteFileFetch(SiteInfoBean bean) throws IOException 88s/Q0l  
{ tq1CwzRX  
siteInfoBean = bean; _}xd}QW  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); I:cg}JZ>|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); i1lBto[  
if(tmpFile.exists ()) S$,'Q^~K  
{ u\yVR$pQ  
bFirst = false; w;6bD'.>;  
read_nPos(); Lh.b 5Q|  
} M5357Q  
else g4p  
{ ] }|byo  
nStartPos = new long[bean.getNSplitter()]; SRIA*M.B}  
nEndPos = new long[bean.getNSplitter()]; ypOLp SYk  
} kYzKU2T\W  
>Gml4vGK  
%QmxA 7fW  
i%m"@7.kk  
} W,5Hx1z R  
W !w,f;  
XRx+Dddt;  
public void run() T;TA7{B  
{ b?X.U}62_  
//获得文件长度 l e4?jQQ@L  
//分割文件 +ZMls [  
//实例FileSplitterFetch @mP]*$00  
//启动FileSplitterFetch线程 RGKYW>$0RR  
//等待子线程返回 )Z 9E=%  
try{ 8Me:Yp_Xt  
if(bFirst) x+8_4>,>Y7  
{ afBE{  
nFileLength = getFileSize(); Ysq'2  
if(nFileLength == -1) {9Y+.46S  
{ ?'86d_8  
System.err.println("File Length is not known!"); g[RI.&?  
} S{pXs&4O  
else if(nFileLength == -2) y;w x?1)  
{ U4f5xUY0)  
System.err.println("File is not access!"); !* Ti}oIo&  
} g9D^)V  
else '.Ed`?<p  
{ NX`*%K  
for(int i=0;i<nStartPos.length;i++) o1W:ox?kO  
{ J%09^5:-z  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); X+L) -d  
} ,YTIC8qKr  
for(int i=0;i<nEndPos.length-1;i++) U$]|~41#  
{ vE@!{*  
nEndPos = nStartPos[i+1]; ~(!XY/0e  
} ?Nf>]|K:Q  
nEndPos[nEndPos.length-1] = nFileLength; j`^$#  
} 61puqiGG^  
} @k[R/,#'[t  
L^2FQti>  
B~o\+n  
//启动子线程 wW>zgTG  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ) [0T16  
for(int i=0;i<nStartPos.length;i++) f` =CpO*  
{ _XJ2fA )  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (" LQll9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), + a- 6Q ~  
nStartPos,nEndPos,i); VE+IKj!VG0  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '!l 1=cZD  
fileSplitterFetch.start(); 4wC+S9I#E^  
} d ;vT ~;  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6"Bic rY  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $o$ maA0  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~P~  
nEndPos = " + nFileLength); M@ed>.  
// fileSplitterFetch[nPos.length-1].start(); ;};wq&b#  
^O^l(e!3  
lY|Jr{+Ln  
//等待子线程结束 y_\p=0t8  
//int count = 0; }*.0N;;C  
//是否结束while循环 ? A(QyaKz  
boolean breakWhile = false; xX*H7#  
x77l~=P+!  
fP.F`V_Y  
while(!bStop) PV|uPuz  
{ ^Ge+~o?x  
write_nPos(); T]2q?; N  
Utility.sleep(500); :'#TCDlOb  
breakWhile = true; ]-ZEWt6lsc  
me[DmiM,  
7AYd!n&S  
for(int i=0;i<nStartPos.length;i++) 0-~\ W(  
{ Fx-8M!  
if(!fileSplitterFetch.bDownOver) 9U$EJN_G  
{ $<:E'^SAS  
breakWhile = false; [9 Ss# ~  
break; sC9&Dgkk  
} I\YV des#  
} w@N  
if(breakWhile) h;6lK$!c  
break; ByCnD  
`jwa<N4e@  
7o8{mp'_  
//count++; 31/Edd"]  
//if(count>4) s kg*  
// siteStop(); os/vtyP:a  
} [IK  )  
%-d]X{J:  
76u&EG%  
System.err.println("文件下载结束!"); T49zcJf;  
} g!-,]  
catch(Exception e){e.printStackTrace ();} kF/9-[]$g,  
} rETRTp0HT  
e^.Fa59  
(V4 ~`i4V  
//获得文件长度 &hRvol\J  
public long getFileSize() .A6(D$ O k  
{ K)J(./  
int nFileLength = -1; 7b<yVP;{  
try{ ULQMG'P^D  
URL url = new URL(siteInfoBean.getSSiteURL()); hWX% 66  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )B[0JrcE  
httpConnection.setRequestProperty("User-Agent","NetFox"); HD(.BW7  
"HPB!)C8(  
s`0QA!G{-  
int responseCode=httpConnection.getResponseCode(); rF]h$Z8o  
if(responseCode>=400) % LJs  
{ J>/w5$h5  
processErrorCode(responseCode); \Ym5<];E  
return -2; //-2 represent access is error x g0iN'e'K  
} I'|$}/\`  
g]*#%Xa  
L:FoSCN Y(  
String sHeader; mauI42  
k+ze74_"  
fMOU$0]$<  
for(int i=1;;i++) R~Ne|V2  
{ k1QpKn*  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fl\ly `_  
//Utility.log(in.readLine()); j$+nKc$  
sHeader=httpConnection.getHeaderFieldKey(i); TA{\PKA)  
if(sHeader!=null) ]Ux<aiY]a  
{ 5H ue7'LS  
if(sHeader.equals("Content-Length")) b#X^=n2  
{ >Q(3*d >  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?mwD*LN3o  
break; )b:7-}d  
} Z?\2F%  
} p\bDY  
else ~$~5qwl  
break; utIX  %0  
} Nqu>6^-z0  
} t25,0<iW  
catch(IOException e){e.printStackTrace ();} e d<n9R  
catch(Exception e){e.printStackTrace ();} kkQVNphc  
}I :OsAw  
XHK70: i  
Utility.log(nFileLength); ^/r7@:  
ho$ +L  
hRCed4qA  
return nFileLength; /Z$&pqs!  
} ~8]NK&J  
dxmE3*b`  
YxP&7oq  
//保存下载信息(文件指针位置) 7(5 4/  
private void write_nPos() >"C,@cN}B  
{ 62Z#Y Q}x  
try{ R00eisd  
output = new DataOutputStream(new FileOutputStream(tmpFile)); )BwjZMJ.N  
output.writeInt(nStartPos.length); .,OVzW  
for(int i=0;i<nStartPos.length;i++) sD=n95`v  
{ Cvf[/C+  
// output.writeLong(nPos); PS[+~>%  
output.writeLong(fileSplitterFetch.nStartPos); mFi&YpH u3  
output.writeLong(fileSplitterFetch.nEndPos); %T~ig[GstX  
} 6Aku1h  
output.close(); tQjLOv+?=  
} } q$ WvY/  
catch(IOException e){e.printStackTrace ();} =F@W gn,  
catch(Exception e){e.printStackTrace ();} (JM5`XwM  
} GSRVe/ [  
!7kG!)40  
O)jWZOVp >  
//读取保存的下载信息(文件指针位置) T87 m?a$  
private void read_nPos() g4l !xT  
{ ](s'L8 (x  
try{ 6*3.SGUY  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RS^lKJ1 U  
int nCount = input.readInt(); L>3x9  
nStartPos = new long[nCount]; hy`?E6=9+  
nEndPos = new long[nCount]; gy_>`16K  
for(int i=0;i<nStartPos.length;i++) lqm1!5dt  
{ h]TQn)X]  
nStartPos = input.readLong(); | y2w9n0D  
nEndPos = input.readLong(); k@'#@ t  
} s mnS DS  
input.close(); MP>dW nl  
} `-p:vq`  
catch(IOException e){e.printStackTrace ();} $GTU$4u  
catch(Exception e){e.printStackTrace ();} fe9LEM8j  
} ;t|Ii8Ne  
^G.B+dG@`x  
P9vA7[  
private void processErrorCode(int nErrorCode) /%;mqrdk  
{ {62n7'U{  
System.err.println("Error Code : " + nErrorCode); QC9eUYe  
} fP(d8xTx2y  
}3OKC2K~  
MZT23 [+  
//停止文件下载 6Q${U7%7  
public void siteStop() y$_eCmq  
{ `nZ)>  
bStop = true; -$dXE+&   
for(int i=0;i<nStartPos.length;i++) e=+?K5q{P(  
fileSplitterFetch.splitterStop(); 28UU60  
JW3B'_0  
/so8WRu.  
} iLkZ"X.'|1  
} TZY3tUx0|G  
//负责部分文件的抓取 {qN 5MsY  
**FileSplitterFetch.java %'X[^W  
*/ 6x%h6<#xh*  
package NetFox; |\7 ET[X q  
,&R/4 :I  
-}KC=,]vh  
import java.io.*; @*6 C=LL  
import java.net.*; Z7=`VNHc  
WjlZ6g2i  
/N&CaH\;^$  
public class FileSplitterFetch extends Thread { a+%6B_|\  
/J WGifH  
ybY]e; v*O  
String sURL; //File URL ;e1ku|>$  
long nStartPos; //File Snippet Start Position 4#:W.]U8  
long nEndPos; //File Snippet End Position ;{U@qQD7  
int nThreadID; //Thread's ID ]3X@_NYj  
boolean bDownOver = false; //Downing is over y9>ZwYN  
boolean bStop = false; //Stop identical ~2gG(1%At9  
FileAccessI fileAccessI = null; //File Access interface %3ICI  
 ~Hr}]  
]hFW 73FV  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }#&#^ B#?O  
{ TztAZ2C  
this.sURL = sURL; ''0fF_P  
this.nStartPos = nStart; W7 #9jo  
this.nEndPos = nEnd; p_${Nj  
nThreadID = id; i:OK8Q{VI  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a-|*?{o  
} Y7*U:I+N  
Aj+2;]M  
V7Ek-2M  
public void run() iqe%=%ZR  
{ SAyufLEv,  
while(nStartPos < nEndPos && !bStop) V0P>YQq9s  
{ cT!\{ ~  
_s .G  
v5QqS8u_C  
try{ 2AO~HxF  
URL url = new URL(sURL); jAm3HI   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +PcmJ  
httpConnection.setRequestProperty("User-Agent","NetFox"); c+hQSm|bf)  
String sProperty = "bytes="+nStartPos+"-"; paD!Z0v&  
httpConnection.setRequestProperty("RANGE",sProperty); 7r~~Y%=C|  
Utility.log(sProperty); B4i!/@0s  
g.zEn/SM  
yL2o}ZbS  
InputStream input = httpConnection.getInputStream(); F)'.g d  
//logResponseHead(httpConnection); 0a-0Y&lQm  
Stu4t==U  
\uza=e  
byte[] b = new byte[1024]; t3&LO~Ye  
int nRead; *fn*h[pV&  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W8KDX_vGJ  
{ d ysC4DS  
nStartPos += fileAccessI.write(b,0,nRead); ,I%g|'2  
//if(nThreadID == 1) 93` AWg/T  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3v5%y '  
} X;"Sx#U  
\ywXi~+kUv  
iC9 8_o_9  
Utility.log("Thread " + nThreadID + " is over!"); 2 -C!jAfd  
bDownOver = true;  wv\w;'  
//nPos = fileAccessI.write (b,0,nRead); L;'"A#Pa  
} ]y1OFKYv  
catch(Exception e){e.printStackTrace ();} Vp3ZwS  
} TwVlg ;  
} \<y#R~7s  
8>WC5%f*  
2&^]k`Aj6D  
//打印回应的头信息 ih P|E,L=L  
public void logResponseHead(HttpURLConnection con) (?(zH3  
{ =Q+= f  
for(int i=1;;i++) /7t>TYip!  
{ =1Oj*x@*4  
String header=con.getHeaderFieldKey(i); eFL=G%  
if(header!=null) xx{PespNt  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %0,#ADCqOe  
Utility.log(header+" : "+con.getHeaderField(header)); R}4So1  
else 2IKnhBSV3  
break; A.EbXo/  
} TiO"xMX  
} JAQb{KefdO  
"6us#T  
FMClSeO7  
public void splitterStop() S=e{MI  
{ uoX:^'q   
bStop = true; EB2!HpuQ3  
} -wSg2'b4E  
YYu6W@m]  
:qIXY/  
} 3 %|86:*  
3P^sM1  
'F$l{iR  
/* Od %"B\  
**FileAccess.java O0pDd4)"  
*//文件访问(定位,写) 49dd5ddr  
package NetFox; b#hDHSdZ,  
import java.io.*; lMg+R<$~I  
i5K[>5  
bS"fkf9  
public class FileAccessI implements Serializable{ O2f-5Y$@  
Ft;^g3N  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f'VX Y-  
RandomAccessFile oSavedFile; i-6F:\;  
long nPos; <oX7P69  
h >s!K9  
% Cv D-![0  
public FileAccessI() throws IOException !`M|C?b  
{ ` M3w]qJ<}  
this("",0); % <q w  
} t`,` 6@d  
aW`Lec{.  
=yyp?WmC8  
public FileAccessI(String sName,long nPos) throws IOException Bb}fj28  
{ A3iFI9Iv  
oSavedFile = new RandomAccessFile(sName,"rw"); }`,t$NV`  
this.nPos = nPos; h?;T7|^  
oSavedFile.seek(nPos); TG+VEL |T  
} 4*cU<  
#[`:'e  
vWf; 'j  
public synchronized int write(byte[] b,int nStart,int nLen) < VSA  
{ @qnD=mE  
int n = -1; 6w(6}m.L^  
try{ U}PiY"S<  
oSavedFile.write(b,nStart,nLen); x*nSHb  
n = nLen; !qN||m CH  
} "G@g" gP  
catch(IOException e) mM-8+H?~b  
{ ktdW`R\+  
e.printStackTrace (); $+3}po\  
} X7i/fm{l'  
kT!9`S\  
pFHz"]  
return n; 9uBM<  
} ~(IB0=A{v  
ZObhF#Y9  
t{WzKy  
} O2BDL1o  
LM-J !44  
lAJxr8 .  
/* 4W)B'+ZK8  
**SiteInfoBean.java ^n"OL*ipG  
*/ Bxfc}vC.  
package NetFox; ;Mpy#yIU.  
 $W9{P;  
$[/&74#0HX  
public class SiteInfoBean { !/3B3cG  
!cAyTl(_  
\&iP`v`K  
private String sSiteURL; //Site's URL `P8Vh+7u  
private String sFilePath; //Saved File's Path B&.FO O  
private String sFileName; //Saved File's Name u( wGl_  
private int nSplitter; //Count of Splited Downloading File }c}| $h^Y  
[h34d5'w  
d~:!#uWyFk  
public SiteInfoBean() J<dVT xK12  
{//nSplitter的缺省值为5 Q'YH>oGh^  
//default value of nSplitter is 5 \a6^LD}B  
this("","","",5); Z]j*9#G1s  
} .72S oT  
sh`s /JRf  
S!G(a"<W  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /`6ZAo m9  
{ "gne_Ye.  
sSiteURL= sURL; qLT>Mz)$ %  
sFilePath = sPath; 3`ELKq  
sFileName = sName; j  S?xk  
this.nSplitter = nSpiltter; KOp162X>r  
'F _8j;  
X(\fN[;  
} weE/TW\e  
<Gt2(;  
UF<uU-C"  
public String getSSiteURL() fe_yqIdk  
{ $n+w$CI)  
return sSiteURL; ;ml)l~~YU  
} LK, bO|  
Pp`*]Ib  
bVL9vNK  
public void setSSiteURL(String value) 3plzHz,x  
{ "(3BvMA&!9  
sSiteURL = value; 8-_QFgY  
} _',prZ*  
nM-h&na{s  
 mi)LP?q  
public String getSFilePath() _/s(7y!  
{ Lv'D^'I  
return sFilePath; 6C]1Q.f;  
} u9}1)9  
B]Y}Hu  
bV8!"{  
public void setSFilePath(String value) z6?)3'  
{ lmxr oHE  
sFilePath = value; B,K>rCZ/  
} FcRW;e8-  
_jNj-)RB_  
v}tag#f5>?  
public String getSFileName() @ W^| ?  
{ P  '>SmQ  
return sFileName; }p!HT6 tZ  
} /u0' 6V  
5fm?Lxr&?  
NDs!a  
public void setSFileName(String value) niqN{  
{ `xywho%/Y  
sFileName = value; 6q]5Es<  
} 72X0Tq 4  
0qo)."V{  
<YOLxR  
public int getNSplitter() AjT%]9 V?  
{ Xy@7y[s]  
return nSplitter; Pj4/xX  
} *+\S yO  
SnFk>`  
o4%y>d)  
public void setNSplitter(int nCount) g"?Y+j  
{ 59%tXiO  
nSplitter = nCount; wmTq` XH)  
} AwTJJ0>  
} \uXcLhXN  
Z7_ zMM  
)E,\H@A  
/* y-j\zK  
**Utility.java rc/nFl 6#  
*/ 8:#rA*Y  
package NetFox; Pp| *J^U 4  
}yJ$SR]t  
w^#L9i'v'  
public class Utility { (vB<%l.&  
@E-\ J7 yh  
}t ;(VynV)  
public Utility() V0%V5>  
{ -W<vyNSr  
^.hoLwp.  
+{/*z  
} Q^q1 ns;r  
~",`,ZXQy  
//线程睡眠 :{ur{m5bX  
public static void sleep(int nSecond) 8Y_ol#\L  
{ 3T e^  
try{ 9:!gI|C  
Thread.sleep(nSecond); Z-U-N  
} '2laTl]`  
catch(Exception e) 2 OwV^-OG  
{ N @#c,,  
e.printStackTrace (); EM/@T}  
} <TE%Prd}`  
} 9{$<0,?  
rS?pWTg"8  
//日志 zt<WXw(  
public static void log(String sMsg) Y= ]dvc  
{ %<\6TZr  
System.err.println(sMsg); !Yw3 d   
} TD9;kN1`  
Xu>r~^w=S  
MzP7Py 8.  
public static void log(int sMsg) OZIW_'Wm/  
{ 24/XNSE,-  
System.err.println(sMsg); w,Lvt }  
} oh KCdT~  
} &E4 0* (C  
8>.J1C  
P{5-Mx!{&  
/* 6}(J6T46M[  
**TestMethod.java p<&Xd}]"^W  
*/ W0C@9&pn6  
package NetFox; 4WN3=B  
dTL5-@  
R-RDT9&<  
public class TestMethod { :mS# h@l  
3"kd jOB  
9Li%KOY  
public TestMethod() ` iJhG^w9M  
{ ///xx/weblogic60b2_win.exe Mze;k3  
try{ =;3fq-  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HoLv`JA  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Sje wuIi1  
SiteFileFetch fileFetch = new SiteFileFetch(bean); |hO~X~P  
fileFetch.start(); c(/VYMJZ&  
} g >'p>}t  
catch(Exception e){e.printStackTrace ();} rx5B=M  
xy<`#  
90# ;?#  
} I"t(%2*q  
#9m$ N  
3G meD/6  
public static void main(String[] args) % ',F  
{ qA:#iJ8w  
new TestMethod(); )$&dg2[  
} if)Y9:{r^  
} k`{@pt.  
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