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http断点续传简单实现(java)

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/* +)zDA:2Wa"  
**SiteFileFetch.java f?Z|>3.2  
*/ D@#0dDT  
package NetFox; XjxPIdX_H  
import java.io.*; #$FY+`  
import java.net.*; n"iNKR>nW  
CldDr<k3  
Mxo6fn6-46  
public class SiteFileFetch extends Thread { N ,+(>?yE  
* flWL  
r?\|f:M3  
SiteInfoBean siteInfoBean = null; //文件信息Bean B=r0?%DX"1  
long[] nStartPos; //开始位置 \9'!"-i  
long[] nEndPos; //结束位置 p'gb)nI  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 I'dj.  
long nFileLength; //文件长度 cs t&0  
boolean bFirst = true; //是否第一次取文件 W+.{4 K  
boolean bStop = false; //停止标志 inZi3@h)T  
File tmpFile; //文件下载的临时信息 jM]d'E?ZLA  
DataOutputStream output; //输出到文件的输出流 \2j|=S6  
wra byRjK  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ka#K [qI  
public SiteFileFetch(SiteInfoBean bean) throws IOException *o!l/>4g  
{ @7fm1b  
siteInfoBean = bean; <FQFv IKg  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); jP+ pA e  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 2)=la%Nx  
if(tmpFile.exists ()) U,'EF[t  
{ vnTq6:f#M  
bFirst = false; kQIfYtT  
read_nPos(); .A(i=!{q  
} |:N>8%@6c  
else * MEe,4  
{ 9s(i`RTM  
nStartPos = new long[bean.getNSplitter()]; x~EKGoz3  
nEndPos = new long[bean.getNSplitter()]; Rjq a_hxrS  
} %kq ^]S2O  
yc[(lq.^n  
8bt53ta  
;T>+,  
} 9#Bx]wy  
;gUXvx~~r  
8aZ$5^z  
public void run() Pxqiv9D<R  
{ +}U2@03I  
//获得文件长度 ~,gLplpG0  
//分割文件 ~r&D6Y  
//实例FileSplitterFetch TY~Vi OC  
//启动FileSplitterFetch线程 x,\!DLq:p  
//等待子线程返回 iDw.i"b  
try{ (ND%}  
if(bFirst) m2O&2[g  
{ jgq{pZ#E  
nFileLength = getFileSize(); 5ITq?%{M  
if(nFileLength == -1) @VK6JjIq  
{ 6G}c1nWU  
System.err.println("File Length is not known!"); OJpj}R  
} 'E-FO_N  
else if(nFileLength == -2) ^C7C$TZS  
{ G6Nb{m  
System.err.println("File is not access!"); \ha-"Aqze3  
} )7Ixz1I9g  
else A=X-;N#  
{ )xt4Wk/  
for(int i=0;i<nStartPos.length;i++) -zKxf@"  
{ =X@o@1  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); f-D>3qSS  
} =cn~BnowY  
for(int i=0;i<nEndPos.length-1;i++) ?Ht=[l=  
{ )Gb,^NGr  
nEndPos = nStartPos[i+1]; e:E# b~{  
} ah+j!e  
nEndPos[nEndPos.length-1] = nFileLength; PsbG|~  
} 6 D/tK|  
} x8\<qh*:  
h e&V# #  
[l*;E f,  
//启动子线程 mU@xc N  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <lj\#'G3  
for(int i=0;i<nStartPos.length;i++) R ]P;sk5  
{ >1ZJ{se  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6P*O&1hv  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [s}/nu~U  
nStartPos,nEndPos,i); 8r^ ~0nm  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WYszk ,E  
fileSplitterFetch.start(); Q7GY3X*kA  
} %4,?kh``D  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m|F:b}0Hb  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w z=z?AZW  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HnU Et/  
nEndPos = " + nFileLength); ,@.EpbB  
// fileSplitterFetch[nPos.length-1].start(); VLdB_r3lQ  
1'O0`Me>#  
Im)EDTm$  
//等待子线程结束 Uc&iZFid2K  
//int count = 0; Uu'dv#4Iw  
//是否结束while循环 $Q/Ya@o  
boolean breakWhile = false; :=fvZAWD  
iM5vrz`n  
hs(W;tR@W  
while(!bStop) ;LMWNy4  
{ c1%rV`)]  
write_nPos(); FjFwvO_.  
Utility.sleep(500); Fo}7hab  
breakWhile = true; _Y!sVJ){,c  
x_!ZycEa  
CS@&^SEj  
for(int i=0;i<nStartPos.length;i++) Lh ap4:  
{ /!T> b:0  
if(!fileSplitterFetch.bDownOver) SlaDt  
{ CDdkoajBa  
breakWhile = false; A'-_TFwW  
break; c\.P/~  
} ,.v7FM^gO  
} v}[dnG  
if(breakWhile) \#6Fm_b] u  
break; ,}J_:\j  
euQ.ArF  
z-,VnhLx  
//count++; q SD9Pue  
//if(count>4) \ZH&LPAY  
// siteStop(); qZ X/@Yxz  
} GwLFL.Ke  
o#D.9K(  
GoE 'L  
System.err.println("文件下载结束!"); yI)~]K r  
} Xy7Z38G  
catch(Exception e){e.printStackTrace ();} jd:B \%#![  
} "A[ b rG  
;t(f1rPyE  
qf8[!5GM  
//获得文件长度 S$[k Q|Am  
public long getFileSize() {{!Y]\2S  
{ rU2iy"L  
int nFileLength = -1; kWW w<cA  
try{ F L=,YP  
URL url = new URL(siteInfoBean.getSSiteURL()); =6T 4>rP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Cifd21v4  
httpConnection.setRequestProperty("User-Agent","NetFox"); ll<NIdf\r  
M1!pQC_9  
\Fb| {6+  
int responseCode=httpConnection.getResponseCode(); -iN.Iuc{b_  
if(responseCode>=400) jH *)%n5,\  
{ Q8qz*v]{  
processErrorCode(responseCode); =Ho"N`Qy  
return -2; //-2 represent access is error lMifpK  
} h(' )"  
t"AzI8O  
lE5v-z? &|  
String sHeader; ycr"Y|  
XL5Es:"+?S  
0 f/.>1M=  
for(int i=1;;i++) %2l7Hmp4H  
{ @pza>^wk  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JPx7EEkZR4  
//Utility.log(in.readLine()); ;#k-)m%  
sHeader=httpConnection.getHeaderFieldKey(i); )qU7`0'8  
if(sHeader!=null) (@sp/:`6  
{ R,_d1^|*w  
if(sHeader.equals("Content-Length")) Vpp&|n9^  
{ Y+-xvx :  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6Bt=^~d  
break; m{%t?w$Au  
} ;4#D,zlO^  
} !<n"6KA.  
else |m G7XL,  
break; z/]q)`G  
} 0$P/jt  
} buMq F-j  
catch(IOException e){e.printStackTrace ();} -J0WUN$2*  
catch(Exception e){e.printStackTrace ();} #exss=as/  
zO=%J)-=  
'vIx#k4D1  
Utility.log(nFileLength); `a]44es9q  
Nt-<W+,  
, c;eN  
return nFileLength; 0GXO&rCG  
} V'gw\mcb  
pchBvly+0  
s(2GFc  
//保存下载信息(文件指针位置) =XY]x  
private void write_nPos() ,^'R_efY  
{ &h~aChJ  
try{ MXvXVhCU  
output = new DataOutputStream(new FileOutputStream(tmpFile)); B]iP't \~  
output.writeInt(nStartPos.length);  0E/:|k  
for(int i=0;i<nStartPos.length;i++) _|{aC1Y!V  
{ k9si| '  
// output.writeLong(nPos); e [0w5)X   
output.writeLong(fileSplitterFetch.nStartPos); Ff4*IOZ}(  
output.writeLong(fileSplitterFetch.nEndPos); j tA*pL'/V  
} Q(@IK&v  
output.close(); D!LX?_cD1i  
} 9'~- U  
catch(IOException e){e.printStackTrace ();} wz /GB8P  
catch(Exception e){e.printStackTrace ();} P=8>c'Q  
} F?4(5 K  
-uR72f  
jUMf6^^  
//读取保存的下载信息(文件指针位置) xFF r  
private void read_nPos() mZvG|P$}  
{ TH1B#Y#<J  
try{ {rH9grb  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GG6% bF  
int nCount = input.readInt(); *OTS'W~t  
nStartPos = new long[nCount]; S"2qJ!.u  
nEndPos = new long[nCount]; 6`H.%zM  
for(int i=0;i<nStartPos.length;i++) xi'>mIT  
{ ^4$ 'KIq  
nStartPos = input.readLong(); cPF<D$B  
nEndPos = input.readLong(); ;[0&G6g  
} C2F0tr|  
input.close(); ~oD8Rnf  
} oduDA:  
catch(IOException e){e.printStackTrace ();} rAqxTdF  
catch(Exception e){e.printStackTrace ();} & eZfQ27$  
} 1cJsj  
o|8`>!hF  
8g/F)~s^F  
private void processErrorCode(int nErrorCode) V64L,u#`l  
{ Zm TDQ`Ix  
System.err.println("Error Code : " + nErrorCode); ^y_fRP~  
} `sHuM*  
$ 17 su')  
JhK/']R  
//停止文件下载 ]Yyia.B  
public void siteStop() t-e5ld~a  
{ |;vi*u  
bStop = true; Sfjje4R  
for(int i=0;i<nStartPos.length;i++) '\DSTr:N  
fileSplitterFetch.splitterStop(); HeN~c<NuB  
v90T{1+M|4  
'3(l-nPiG^  
} \ZXLX'-  
} ,TC;{ $O5  
//负责部分文件的抓取 x8#ODuH  
**FileSplitterFetch.java rP=sG;d  
*/ 773/#c  
package NetFox; +Ezgn/bS&  
5F $V`kYT  
CQg X=!q  
import java.io.*; QBJ3iQs1  
import java.net.*; _%@=Uc6V  
x%> e)L<  
\' li  
public class FileSplitterFetch extends Thread { y }2F9=  
g[z.*y/  
 -7]Xjb5  
String sURL; //File URL :VA.QrKW  
long nStartPos; //File Snippet Start Position H:{7X1bV  
long nEndPos; //File Snippet End Position Xh+ia#K  
int nThreadID; //Thread's ID hZ\+FOx;  
boolean bDownOver = false; //Downing is over 8nNsrat  
boolean bStop = false; //Stop identical QL7>;t;  
FileAccessI fileAccessI = null; //File Access interface Hgc=M  
W  0[N0c  
Uu p(6`7  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F phDF  
{ }E^S]hdvz  
this.sURL = sURL; X=X\F@V:u  
this.nStartPos = nStart; B0UJq./`  
this.nEndPos = nEnd; ZXb0Y2AVx  
nThreadID = id; 7 6fIC  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L#h:*U{@40  
} vR7HF*8  
B/uniR^x  
w Fn[9_`*  
public void run() ~4,I7c7  
{ ><?BqRm+  
while(nStartPos < nEndPos && !bStop) `m~syKz4A  
{ V`hu,Y;%  
f6=w3RS  
D$e B ,~  
try{ x2VBm$>  
URL url = new URL(sURL); WgR4Ix^L#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *<V^2z$y_  
httpConnection.setRequestProperty("User-Agent","NetFox");  3yS  
String sProperty = "bytes="+nStartPos+"-"; TW&DFKK`  
httpConnection.setRequestProperty("RANGE",sProperty); JN3cg  
Utility.log(sProperty); ``Q 2P%  
^C^*,V3  
'C+;r?1!h  
InputStream input = httpConnection.getInputStream(); *e"a0  
//logResponseHead(httpConnection); cd@.zg'sYn  
8%{q%+  
jk~:\8M(A  
byte[] b = new byte[1024]; !mfJpJ  
int nRead; dx_6X!=.J  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) eARk QV  
{ ZDLMMX x>  
nStartPos += fileAccessI.write(b,0,nRead); Bd0eC#UGkQ  
//if(nThreadID == 1) ;^k7zNf-  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o,Z{ w"  
} *iX e^<6v  
Bn wzcl  
7hNb/O004  
Utility.log("Thread " + nThreadID + " is over!"); /L=(^k=a.;  
bDownOver = true; 3HV%4nZLf  
//nPos = fileAccessI.write (b,0,nRead); yYJY;".H  
} Al"3 kRJJ  
catch(Exception e){e.printStackTrace ();} 9|r* pK[  
} MLVB^<qkeH  
} ,8Iv9M}2  
m 40m<@  
6)RbPPeE  
//打印回应的头信息 >O9 sk  
public void logResponseHead(HttpURLConnection con) &rq{v!=7  
{ i\}:hU-U  
for(int i=1;;i++) iAO5"(>}?  
{ `|e!Kq?#Q  
String header=con.getHeaderFieldKey(i); IfdI|ya  
if(header!=null) d 4{FDqto  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BuQ|~V  
Utility.log(header+" : "+con.getHeaderField(header)); h#YD~!aJ  
else  ^y.UbI  
break; KpZ:Nh$  
} JyBp-ii  
} FVWfDQ$&v  
[`fI:ao|  
&vUq}r%P  
public void splitterStop() 'JmBh@A  
{ q ojXrSb"y  
bStop = true; ^J=hrYGA  
} 6o&ZIYJ9k  
oh8L`=>&a  
PBqy F  
} {[G`Z9]z&-  
$K}. +`vVO  
('k<XOi  
/* @M;(K<%h  
**FileAccess.java [uuj?Rbd  
*//文件访问(定位,写) s'I)A^i+  
package NetFox; :Hy]  
import java.io.*; n~0z_;5  
ZXiRw)rM  
/="HqBI#i  
public class FileAccessI implements Serializable{ D9ufoa&ua  
#B}?Zg  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a=]W zlz  
RandomAccessFile oSavedFile; LgqGVh3\s  
long nPos; 3!9 Z=- tD  
^JeMuU  
HD`>-E#  
public FileAccessI() throws IOException F3E[wdT  
{ Gm8E<iTP  
this("",0); Q s(Bnb;  
} 9(1rh9`=  
#*$p-I=  
 !rL<5L  
public FileAccessI(String sName,long nPos) throws IOException kEN#u  
{ %CH6lY=lI  
oSavedFile = new RandomAccessFile(sName,"rw"); ]?l{j  
this.nPos = nPos; O12Q8Oj!0  
oSavedFile.seek(nPos); C 0C0GqN,  
} H'g?llh1J  
4cgIEw[6  
0irr7Y  
public synchronized int write(byte[] b,int nStart,int nLen) ROAI9sW0  
{ 4*H"Z(HP  
int n = -1; >%%=0!,yX  
try{ X T>('qy  
oSavedFile.write(b,nStart,nLen); }uO5q42  
n = nLen; Iin#Wd-/  
} b{[*N  
catch(IOException e) 4SVW/Zl.?  
{ yyl#{Nl@t  
e.printStackTrace (); QJ X/7RA  
} Cnh|D^{s  
,Qc.;4s-  
#a~"K|' G  
return n; HCnf2td  
} F9o6V|v  
|m>}%{  
~1 ZD[@  
} e- 6w8*!i  
#6> 6S;Ib  
FvImX  
/* W4(?HTWZ  
**SiteInfoBean.java C8b''9t.  
*/ ?[1SiJT  
package NetFox; +oy*Kxs7  
;Rnhe_A.  
)iE"Tl  
public class SiteInfoBean { BSUPS+@+  
.XH8YT42  
\_ow9vU  
private String sSiteURL; //Site's URL vgG}d8MW37  
private String sFilePath; //Saved File's Path wyQb5n2`;~  
private String sFileName; //Saved File's Name EA0iYzV  
private int nSplitter; //Count of Splited Downloading File K&`Awv  
ohZx03  
x7ATI[b[  
public SiteInfoBean() ?Myh 7  
{//nSplitter的缺省值为5 @)0 Y~A )  
//default value of nSplitter is 5 %v=!'?VT  
this("","","",5); F @SG((`  
} 9YKDguG  
kK[duW =6  
Da,Tav%b  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mnQ'X-q3iO  
{ 4F#%f#"  
sSiteURL= sURL; R } %8s*  
sFilePath = sPath; :t$A8+A+0  
sFileName = sName; {8CWWfHCD  
this.nSplitter = nSpiltter; &=w|vB)(p  
UzQ$B>f  
avNLV  
} PdE>@0X?M  
7'j9rmTXs  
Mtp%co)f  
public String getSSiteURL() esq<xuZM4  
{ 6Z c)0I'  
return sSiteURL; lo:~aJ8  
} Q"}s>]k3_  
L3c*LL  
19I:%$U3  
public void setSSiteURL(String value) ^Q2ZqAf^a  
{ -u6#-}S  
sSiteURL = value; /bcY6b=:  
} ixI:@#5wY  
@YZ 4AC  
.E<Dz  
public String getSFilePath() +TX/g~  
{ *x,HnHT  
return sFilePath; >>V&yJ_  
} > V%Q O>C  
h6QWH  
<94WZ?{p  
public void setSFilePath(String value) |5ONFd e"0  
{ FdxsU DL  
sFilePath = value; [x_s/"Md;  
} otq,R6 ^  
l9Pu&M?5  
$9H[3OZPVv  
public String getSFileName() jT^!J+?6K+  
{ Bl4 dhBZoO  
return sFileName; fN[n>%)VO<  
} {j@+h%sF>+  
-Enbcz(B  
jsm0kz  
public void setSFileName(String value) P9yw&A  
{ #s^s_8#&e  
sFileName = value; cjT[P"5$  
} sp{j!NSL  
dXZP[K#  
Lz6*H1~   
public int getNSplitter() .mt^m   
{ }su6izx  
return nSplitter; s=/^lOOO  
} Q \WXi  
ZKQo#!}  
yBe(^ n  
public void setNSplitter(int nCount) ZR mPP  
{ ?!m m a\W  
nSplitter = nCount; t|=n1\=?  
} 2Iz fP;V?  
} $jcz?vH  
k~|ZO/X@l%  
;tr)=)q &  
/* Oga1u  
**Utility.java ,\>g  
*/ ua:9`+Dff  
package NetFox; 88YC0!Ni  
_LsYMUe  
L9J;8+ge  
public class Utility { ^0eO\wc?O  
-x?Hj/  
E7 L bSZ  
public Utility() /&6Q)   
{ y4r2}8fi  
!qS05  
+{^'i P  
} $w`veP  
B3 .X}ys#  
//线程睡眠 `&,_xUA  
public static void sleep(int nSecond) /J.0s0 @  
{ H<z30r/-w  
try{ Di])<V  
Thread.sleep(nSecond); pLo;#e8'f  
} m9I(TOw  
catch(Exception e) f~iML5lG  
{ 1O4D+0@  
e.printStackTrace (); Vy r] x  
} w'XSb.\)_m  
} x{j+}'9  
T7s+9CE  
//日志 2_I+mQ  
public static void log(String sMsg) -G!6U2*#  
{ o[imNy~~  
System.err.println(sMsg); 4V>vg2 d  
} K"I{\/x@  
lXw;|dGF  
vhX-Qkt}  
public static void log(int sMsg) 1"d\ mE  
{ C?(y2p`d\  
System.err.println(sMsg); w4aiI2KFq  
} Uv'uqt  
} 9QZ}Hn`p  
5@iy3olP  
Sn0Xl3yr  
/* sB8p( L  
**TestMethod.java %'kX"}N/  
*/ epYj+T  
package NetFox; sI4QI\*4  
wNbTM.@  
i(z+a6^@|  
public class TestMethod { iPz1eUj  
R'r|E_  
R rxRa[{Z  
public TestMethod() ^|r`"gOJ3  
{ ///xx/weblogic60b2_win.exe zQ=aey%  
try{ t3 K>\ :  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <w;D$l}u  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L#[HnsLp_  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 65uZ LsQ  
fileFetch.start(); P mC82"  
} VBhE{4J  
catch(Exception e){e.printStackTrace ();} ?3n=m%W,J*  
qPp]K?.  
2,+@# q  
} rdFs?hO  
pDP33`OFh  
<%he  o  
public static void main(String[] args) (tTLK0V-|3  
{ e1oFnu2R  
new TestMethod(); )!BB/'DRQ  
} KqFmFcf|  
} _AVy:~/  
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