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http断点续传简单实现(java)

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/* "7y, d%H  
**SiteFileFetch.java yn}Dj9(q  
*/ \1G '{# Q  
package NetFox; ,B'=$PO%  
import java.io.*; y:98}gW`n  
import java.net.*; AC1RP`c  
\4wMv[;7  
#dae^UjM  
public class SiteFileFetch extends Thread { 0#OyT'~V%  
<~5O-.G]  
F:q4cfL6  
SiteInfoBean siteInfoBean = null; //文件信息Bean D%]S>g5k  
long[] nStartPos; //开始位置 _ cQ '3@  
long[] nEndPos; //结束位置 is8i_FoD,n  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 vcdVck@  
long nFileLength; //文件长度 " Bx@(  
boolean bFirst = true; //是否第一次取文件 GIzB1cl:  
boolean bStop = false; //停止标志 6Yn>9llo}=  
File tmpFile; //文件下载的临时信息 (*$F7oO<  
DataOutputStream output; //输出到文件的输出流 }qso} WI  
]Z5m_-I  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) R?iCJ5m  
public SiteFileFetch(SiteInfoBean bean) throws IOException Cg]|x+  
{ KV$&qM.  
siteInfoBean = bean; 53{\H&q  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); TiI/I`A  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); KbLSK  
if(tmpFile.exists ()) w{aGH/LN  
{ 3h:~NL  
bFirst = false; } doAeTZ  
read_nPos(); 3GF67]  
} eZOR{|z  
else .4^+q9M  
{ _aevaWtEx  
nStartPos = new long[bean.getNSplitter()]; \85%d0@3  
nEndPos = new long[bean.getNSplitter()]; }y6@YfV${  
} nDdY~f.B  
5(ZOm|3ix  
kVQm|frUz  
G/p\MzDko  
} G^t)^iI"'  
Uap0O2n  
FDD=I\Ic  
public void run() ~\JB)ca.  
{ Zq 85q  
//获得文件长度 J[:#(c&c!1  
//分割文件 $B-/>Rz  
//实例FileSplitterFetch 0RA#Y(IR  
//启动FileSplitterFetch线程 B{&W|z{$  
//等待子线程返回 L@GICW~  
try{ { .$7g8]I  
if(bFirst) mv99SOe[Fz  
{ -:%QoRC y  
nFileLength = getFileSize(); C/Q20  
if(nFileLength == -1) yS~Y"#F!.  
{ "O>~osj  
System.err.println("File Length is not known!"); g)czJ=T2  
} "b`#RohCi  
else if(nFileLength == -2) dh`s^D6Q>  
{ [T_[QU:A  
System.err.println("File is not access!"); e#Ao] gc  
} jdG2u p  
else HSNj  
{ G,!jP2S  
for(int i=0;i<nStartPos.length;i++) ^slIR!L  
{ LSc^3=X  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ^WB[uFt-  
} ,nYa+e  
for(int i=0;i<nEndPos.length-1;i++) 3R< r[3WP  
{ w3,KqF  
nEndPos = nStartPos[i+1]; CmBP C jh  
} ^$P_B-C N  
nEndPos[nEndPos.length-1] = nFileLength; :G 5p`;hGo  
} K*j OrQf`  
} o4p5`jOG@  
hx0t!k(3  
3g!Z[SZ  
//启动子线程 4A@HR  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wd7*7']  
for(int i=0;i<nStartPos.length;i++) 8J'5%$3u  
{ u;$qJjS N  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B0b|+5WhR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k_}$d{X  
nStartPos,nEndPos,i); $V 3If  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L?nhm=D  
fileSplitterFetch.start(); MXaik+2  
} t#P7'9Se8  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |.Vgk8oTl  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v];YC6shx  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8i] S[$Fc  
nEndPos = " + nFileLength); (Z>?\iNJ  
// fileSplitterFetch[nPos.length-1].start(); mh"PAp  
o=Z:0Ukl]  
*Hn=)q  
//等待子线程结束 zqj|$YNC  
//int count = 0; Fxa{ 9'99  
//是否结束while循环 ,|RKM  
boolean breakWhile = false; i}8OaX3x  
(.N n|lY<i  
E'{:HX  
while(!bStop) @lDnD%vZ`  
{ n>u_>2Ikkj  
write_nPos(); 9<rs3 84  
Utility.sleep(500); ]vf_4QW=  
breakWhile = true; OSO MFt  
m&=Dy5  
Rp2h[_>  
for(int i=0;i<nStartPos.length;i++) b)IQa,enH  
{ 8g8eY pG  
if(!fileSplitterFetch.bDownOver) %TI3Eb  
{ jX4$PfOhR  
breakWhile = false; ^!^M Gzu  
break; -sv%A7i  
} mxCneX  
} *^@b0f~vj  
if(breakWhile) k 76<CX  
break; ?a,#p  
6P@K]jy& n  
cu1!WD  
//count++; 8zMGpY#  
//if(count>4) rEp\ld  
// siteStop(); C"n!mr{srt  
} O\Y*s  
P'B|s /)  
U~BR8]=G  
System.err.println("文件下载结束!"); rYt|[Pk  
} kO`!!M[Oo  
catch(Exception e){e.printStackTrace ();} x_O:IK.>  
} 92Gfxld\  
uy2~<)  
-,*m\Fe}  
//获得文件长度 a=ZVKb  
public long getFileSize() {w3<dfJ  
{ pFd{Tdh  
int nFileLength = -1; kJB:=iq/x$  
try{ .7 j#F  
URL url = new URL(siteInfoBean.getSSiteURL()); uDG>m7(}/h  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 38-kl,Vw  
httpConnection.setRequestProperty("User-Agent","NetFox"); @>VX]Qe^X  
zK~_e\m  
!lg_zAV  
int responseCode=httpConnection.getResponseCode(); 9+*{3 t  
if(responseCode>=400) Heqr1btK  
{ PSAEW.L  
processErrorCode(responseCode); Y/UvNb<lK  
return -2; //-2 represent access is error vO?sHh  
} Zt41fPQ  
7>zUT0SS  
[H!do$[>  
String sHeader; Z~(X[Zl :  
VG7#C@>Z  
19R~&E's  
for(int i=1;;i++) &to~#.qc  
{ U7U&^s6`  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1h`F*:nva  
//Utility.log(in.readLine()); OSuQ7V  
sHeader=httpConnection.getHeaderFieldKey(i); KgYQxEbIW  
if(sHeader!=null) IX 6 jb"  
{ }Uj-R3]}K  
if(sHeader.equals("Content-Length")) HrLws95'  
{ _~1O#*|4  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jon3ywd1Y  
break; EpACd8Fb  
} C+!=C{@7di  
} Y[b08{/  
else .(p_YjIA  
break; P;XA|`&  
} ShtV2}s|  
} d$\n@}8eZp  
catch(IOException e){e.printStackTrace ();} OPUrz?p2C  
catch(Exception e){e.printStackTrace ();} {gEz;:!):  
l(QntP  
(i{ZxWW&  
Utility.log(nFileLength); qldm"Ul  
PU\xFt  
MsIaMW_  
return nFileLength; |R91|-H  
} -{A64gfFxT  
}|/<!l+;$  
u9q#L.Ij  
//保存下载信息(文件指针位置) 6e,IjocsB  
private void write_nPos() mbhh  
{ |w~*p N0  
try{ ,3G B9  
output = new DataOutputStream(new FileOutputStream(tmpFile)); oKkDG|IE  
output.writeInt(nStartPos.length); wE9z@\z]  
for(int i=0;i<nStartPos.length;i++) vfDX~_N  
{ Iza#v0  
// output.writeLong(nPos); yHf^6|$8  
output.writeLong(fileSplitterFetch.nStartPos); {J)gS  
output.writeLong(fileSplitterFetch.nEndPos); m(xyEU  
} Y*jkUQ  
output.close(); C@XnV=J  
} 4%yeEc ;z  
catch(IOException e){e.printStackTrace ();} B&!>& Rbx  
catch(Exception e){e.printStackTrace ();} ;x|? N*  
} _Nz?fJ:$@  
F` gK6;zp  
n|.>41bJ  
//读取保存的下载信息(文件指针位置) 9O&MsTmg$  
private void read_nPos() _jCu=l_  
{ W`#E[g?]  
try{ T.{]t6t$U  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HD$ r<bl  
int nCount = input.readInt(); s}gdi  
nStartPos = new long[nCount]; W+V &  
nEndPos = new long[nCount]; -:!T@rV,d  
for(int i=0;i<nStartPos.length;i++) gi_f8RP=2a  
{ H%>cpwa[7  
nStartPos = input.readLong(); nH?#_ 5F1  
nEndPos = input.readLong(); 2jQ?-/Q8#  
} }*P;kV  
input.close(); d_V7w4lK  
} $ JCOL  
catch(IOException e){e.printStackTrace ();} DoeE=X*`k  
catch(Exception e){e.printStackTrace ();} LmROG-9  
} n#P?JyGm1g  
5NK yF  
}&Xf<6  
private void processErrorCode(int nErrorCode) IQ~EL';<w  
{ Hb$wawy<  
System.err.println("Error Code : " + nErrorCode); J rYL8 1  
} cKwmtmwB  
nl-tJ.MU"  
L6=5]?B=  
//停止文件下载 <HW2W"Go\  
public void siteStop() 8f&#WIZ  
{ uF*tlaV6  
bStop = true; :G<~x8]k0  
for(int i=0;i<nStartPos.length;i++) gHvkr?Cg  
fileSplitterFetch.splitterStop(); wD pL9q  
lz#@_F|.*  
Hg(nC*#/Q  
} Es:oXA  
} EF6"PH+J@  
//负责部分文件的抓取 m FC9\   
**FileSplitterFetch.java <;Td8T;  
*/ ,UT :wpc^i  
package NetFox; ~05(92bK  
8\`otJY  
*U,W4>(B  
import java.io.*; cbx( L8  
import java.net.*; 1[?xf4EMG  
bFIv}c+;  
j4D`Xq2 X  
public class FileSplitterFetch extends Thread { Zr!CT5C5  
te3\MSv;O  
y2x)<.cDP  
String sURL; //File URL _cc9+o  
long nStartPos; //File Snippet Start Position wqQrby<  
long nEndPos; //File Snippet End Position rY=dNK]d  
int nThreadID; //Thread's ID \z-OJ1[F  
boolean bDownOver = false; //Downing is over R|7_iMIZ  
boolean bStop = false; //Stop identical ]<o^Q[OL  
FileAccessI fileAccessI = null; //File Access interface d+7Dy3i|g=  
PrEfJ?  
sGbk4g  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _7-P8"m  
{ H#I%6k*\a  
this.sURL = sURL; `hl1R3nBM  
this.nStartPos = nStart; Wl>$<D4mO[  
this.nEndPos = nEnd; 9>L{K   
nThreadID = id; 7/c9azmC  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \v.YP19  
} .t%` "C  
^ G>/;mZ  
=/^{Pn  
public void run() E K^["_*A  
{ u6p nO  
while(nStartPos < nEndPos && !bStop) V34]5  
{ EDGAaN*Q  
p~t5PU*(  
+JBYGYN&K  
try{ b@N*W]  
URL url = new URL(sURL); bdyE9t   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HNL;s5gq  
httpConnection.setRequestProperty("User-Agent","NetFox"); P/~kX_  
String sProperty = "bytes="+nStartPos+"-"; mr#XN&e  
httpConnection.setRequestProperty("RANGE",sProperty); zJtB?<  
Utility.log(sProperty); ~VO?PfxZ  
:eTzjW=  
'ul~f$ V  
InputStream input = httpConnection.getInputStream(); (L8z<id<z  
//logResponseHead(httpConnection); O(44Dy@2  
JclG*/Wjg4  
~]lVixr9  
byte[] b = new byte[1024]; P'CDV3+  
int nRead; -]vPF|  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p7Q %)5o  
{ .R>4'#8q  
nStartPos += fileAccessI.write(b,0,nRead); IgU65p  
//if(nThreadID == 1) xs3t~o3y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZzV%+n7<Vx  
} El`f>o+EJ  
aY@st]p  
lip1wR7  
Utility.log("Thread " + nThreadID + " is over!"); $P%b?Y/  
bDownOver = true; f^[:w1X$sM  
//nPos = fileAccessI.write (b,0,nRead); 3XomnL{  
} #i~2C@]  
catch(Exception e){e.printStackTrace ();} hA_Y@&=W  
} YF<;s^&@u  
} QO%#.s  
")ZsY9-P  
F~_)auH  
//打印回应的头信息 vT>ki0P_;  
public void logResponseHead(HttpURLConnection con) 7IH^5r  
{ 3[O;HS3|  
for(int i=1;;i++) A#B6]j)  
{ 34\:1z+s M  
String header=con.getHeaderFieldKey(i); u|a+ :r)*4  
if(header!=null) <[mvfw  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i=G.{.  
Utility.log(header+" : "+con.getHeaderField(header)); qdeS*r p\  
else -P>f2It  
break; ;\Vi~2!8  
} /_ MEb42&  
} cfEi]  
2m/=0sb\{  
'v*Y7zZ#K  
public void splitterStop() BVpRkUC"  
{ L=wg"$  
bStop = true; hhVyz{u  
} m;"i4!  
MHVHEwr.{  
e+5]l>3)f  
} K6Gri>Um  
fhZD#D  
\f7A j>  
/* 3Vj,O?(Z  
**FileAccess.java On{p(| l  
*//文件访问(定位,写) (X"WEp^Q{I  
package NetFox; Gf{FFIe(  
import java.io.*; AK*F,H9  
U0kEhMIIf  
^SouA[  
public class FileAccessI implements Serializable{ ?!J{Mrdn  
s-He  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w Kq-|yf,  
RandomAccessFile oSavedFile; aI6fPQe  
long nPos; ['SZe0  
<"" fJ`7  
do:3aP'S,  
public FileAccessI() throws IOException 62X;gb  
{ ag$mc8-p[  
this("",0); 6(`Bl$M9  
} hK t c  
~#b&UR  
.WR+)^&zz  
public FileAccessI(String sName,long nPos) throws IOException 5)MVkJ=R  
{ *y;(c)_w/%  
oSavedFile = new RandomAccessFile(sName,"rw"); 3d2|vQx,K  
this.nPos = nPos; IwHYuOED]  
oSavedFile.seek(nPos); Gn*vVZ@`x  
} "c6(=FFq  
6^ ]Y])  
tDl1UX  
public synchronized int write(byte[] b,int nStart,int nLen) K)AJx"  
{ Q`dzn=  
int n = -1; [CU]fU{$  
try{ ]oN:MS4r  
oSavedFile.write(b,nStart,nLen); 5mD]uB9  
n = nLen; vbeYe2;(  
} Cku&s  
catch(IOException e) q>T7};5m2  
{ 8yH*  
e.printStackTrace ();  ?vgHu  
} :Z@!*F  
S;vE %  
Z[DiLXHL  
return n; { L(Q|bB  
} Q_bF^4gt  
+a%Vp!y  
RQZ|:SvV  
} F;mK)Q-  
}?pY~f  
sz'IGy%  
/* KMxP%dV/=  
**SiteInfoBean.java "YUyM5X  
*/ IQFt4{aK3  
package NetFox; {o?+T );Z  
6}YWM]c%  
^&'&Y>  
public class SiteInfoBean { )vFJx[a<n`  
wj fk >  
jrMY]Ea2`  
private String sSiteURL; //Site's URL  p=Nord  
private String sFilePath; //Saved File's Path ubn`w=w$  
private String sFileName; //Saved File's Name >4A~?=  
private int nSplitter; //Count of Splited Downloading File ,1"w2,=  
'[ZRWwhr  
cC.=,n  
public SiteInfoBean() LCrE1Q%VP  
{//nSplitter的缺省值为5 |=7ouFl  
//default value of nSplitter is 5 XCNfogl  
this("","","",5); A Z7  
} Nj2f?',;U  
o5(p&:1M  
8:%=@p>$  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?qeBgkL(B^  
{ J Cu3,O!q  
sSiteURL= sURL; zW`$T 88~  
sFilePath = sPath; YEZd8Y  
sFileName = sName; Zc"Vf]:  
this.nSplitter = nSpiltter; :wJ=t/ho  
$td=h)S^`  
:>U2yI  
} %z6.}4h  
'1lr "}"Q+  
5 } 9}4e  
public String getSSiteURL() X]J]7\4tF\  
{ 7gR8Wr ^  
return sSiteURL; =(f+geA"hm  
} h*_h M1*;  
"5]Fl8c?  
_`>F>aP  
public void setSSiteURL(String value) D}SYv})Ti  
{ EK^B=)q6:W  
sSiteURL = value; ;- D1n  
} bwjjwu&  
3@ a  
JJHr<|K  
public String getSFilePath() sN^3bfi!i  
{ &+?JY|u  
return sFilePath; @(Mg>.P  
} \bze-|C  
r7z8ICX'q  
#On EQ:  
public void setSFilePath(String value) lP>}9^7I!  
{ Vy-EY*r|  
sFilePath = value; C3n_'O  
} 2\flTO2Ny  
;\@co5.=  
olNgtSX  
public String getSFileName() T~%}(0=m  
{ HH>"J /;c,  
return sFileName; cTO\Vhg  
} 8Wn;U!qT  
wN[mU  
;2||g8'  
public void setSFileName(String value) -c-#1_X5  
{ Ju""i4  
sFileName = value; EP.nVvuL  
} =yv_i]9AN  
W\s ]qsLS  
GY@-}p~it  
public int getNSplitter() L-}>;M$Y)  
{ box(FjrZE  
return nSplitter;  (f DA  
} E|ce[|2  
cd8~y  
tAfdbt  
public void setNSplitter(int nCount) xtef18i>  
{ 1Ih.?7}  
nSplitter = nCount; I\JJ7/S`t  
} ;=IC.<Q<}  
} $d1+d;Mn  
=VMV^[&>  
Oj<.3U[C  
/*  8+no>%L  
**Utility.java GE`:bC3  
*/ ,f`435R  
package NetFox; k r0PL)$  
#hEN4c[Ex  
W+ tI(JZ  
public class Utility { vkdU6CZO  
G1 ?."  
+8e~jf3E1  
public Utility() | ,bCYK  
{ __p\`3(,'  
E DuLgg@  
Qe=,EXf  
} k!e \O>+  
N zY}-:{  
//线程睡眠 I^iJ^Z]vx  
public static void sleep(int nSecond) F+A"-k_\T#  
{ BU[ .P]  
try{ BJI}gm2y  
Thread.sleep(nSecond); w%=GdA=  
} TrxZS_  
catch(Exception e) j4wcxZYY~  
{ ,?Pn-aC +  
e.printStackTrace (); #J. v[bOWQ  
} h^F^|WT$  
} M_tY:v  
Ri]7=.QI`  
//日志 ~~[Sz#(  
public static void log(String sMsg) 2}Dd{kC-  
{ YfBb=rN2s  
System.err.println(sMsg); 0-H!\IB  
} _3UH"9g{  
z;:c_y!f  
6QsH?!bu  
public static void log(int sMsg) 3L$_OXx  
{ -%]O-'  
System.err.println(sMsg); %(a<(3r  
} a!MhxM5  
} L8K= Q  
5y7rY!]Bf  
#3@ Du(_n  
/* 2j_YHv$I  
**TestMethod.java a hi lp$v  
*/ 3w9j~s  
package NetFox; ?bc-?<Xk  
)X{x\ /N  
%u\Oj \8U  
public class TestMethod { *"V5j#F_  
 :[:5^R  
 6e,|HV  
public TestMethod() D>9~JHB  
{ ///xx/weblogic60b2_win.exe tx}} Kd  
try{ J(*q OGBD  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aY8"Sw|4  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >jEn>H?  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Xz)UH<  
fileFetch.start(); 'Eds0"3  
} -x~h.s,  
catch(Exception e){e.printStackTrace ();} m9bR %j  
&jCT-dj  
* z|i{=W F  
} Wx#((T  
< aeBhg%  
q[4{Xh  
public static void main(String[] args) \F]X!#&+  
{ )(~s-x^\z@  
new TestMethod(); o JC-?  
} OgJd^  
} CW*Kd t  
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