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http断点续传简单实现(java)

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/* {=mf/3.r  
**SiteFileFetch.java P`r@<cgb=  
*/ =v^LShD2^  
package NetFox; }dcXuX4{r  
import java.io.*; 4)MKYhm  
import java.net.*; v0uDL7  
!qGER.  
z H$^.1  
public class SiteFileFetch extends Thread { ffyDi1Q  
XG_h\NIL  
v:/+Oz Y  
SiteInfoBean siteInfoBean = null; //文件信息Bean 3j<:g%5  
long[] nStartPos; //开始位置 NqyKR&;  
long[] nEndPos; //结束位置 ueI1O/Mi  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 me-Tv7WL  
long nFileLength; //文件长度 jw63sn  
boolean bFirst = true; //是否第一次取文件 'dJ#NT25  
boolean bStop = false; //停止标志 /$ a>f>EJ  
File tmpFile; //文件下载的临时信息 lO^Ly27  
DataOutputStream output; //输出到文件的输出流 ^3~+|A98M  
\l)Jb*t  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) [I6(;lq2  
public SiteFileFetch(SiteInfoBean bean) throws IOException (4:&tm/;  
{ Y]>!uwn  
siteInfoBean = bean; $glt%a  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); JH3$G,:zM  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); /~sNx  
if(tmpFile.exists ()) w=e_@^Fkx  
{ Std?p{ i  
bFirst = false; }5_[t9LX  
read_nPos(); z= \y)'b  
} k OYF]^uJ  
else g2?kC^=z=  
{ 9, A(|g  
nStartPos = new long[bean.getNSplitter()]; 9E`WZo^.  
nEndPos = new long[bean.getNSplitter()]; ^a>3U l{  
} ?+3vK=Rf}  
_LVwjZX[  
U%.%:'eV=  
\\ZR~f!<  
} JAt$WW{  
g=ehAg  
pJg'$iR!/  
public void run() N@qP}/}8  
{ seQSDCsvw*  
//获得文件长度  f$7Xh~  
//分割文件 cd&^ vQL8  
//实例FileSplitterFetch :| s  
//启动FileSplitterFetch线程 ;+ -@AYl  
//等待子线程返回 ^l,(~03_  
try{ n'?AZ4&z  
if(bFirst) 7d m:L'0  
{ xX !`0T7Y  
nFileLength = getFileSize(); 95XQ?%  
if(nFileLength == -1) Oc,E\~  
{ biLNR"/E  
System.err.println("File Length is not known!"); @p$Nw.{'  
} KF.O>c87&  
else if(nFileLength == -2) 24g\x Nnt  
{ \X*Es.;|x  
System.err.println("File is not access!"); xmM!SY>  
} _YK66cS3E/  
else (yJY/|  
{ cD%_+@GaU  
for(int i=0;i<nStartPos.length;i++) ]\JLlQ}#H  
{ 2@Nt6r  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); z [|:HS&  
} JI3x^[(Z  
for(int i=0;i<nEndPos.length-1;i++) = :/4)  
{ ,<CFjtelO  
nEndPos = nStartPos[i+1]; g7UZtpLTm  
} )K}-z+$)k  
nEndPos[nEndPos.length-1] = nFileLength; /Kd9UQU  
} GXnrVI  
} o*t4zF&n  
QomihQnc  
tH)fu%:p  
//启动子线程 Pf:;iXH?  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p9y@5z  
for(int i=0;i<nStartPos.length;i++) kf:Nub+h t  
{ z 0}JiWR  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %TeH#%[g>\  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |muZv!,E  
nStartPos,nEndPos,i); hh[@q*C  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QPyHos `  
fileSplitterFetch.start(); b[2 #t  
} Yh["IhjR  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S]Qf p,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8Q(A1U  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B fu/w   
nEndPos = " + nFileLength); eyzXHS*s;L  
// fileSplitterFetch[nPos.length-1].start(); 0aqq*e'c  
0O!A8FA0  
<dKHZ4  
//等待子线程结束 moD)^':.  
//int count = 0; | vPU]R>6  
//是否结束while循环 A D%9;KQ8  
boolean breakWhile = false; xqpq|U  
n #S?fsQN  
`$Y%c1;  
while(!bStop) 2@Zw#2|]  
{ N5 b^  
write_nPos(); .^wBv 'Y  
Utility.sleep(500); =bOMtQ]  
breakWhile = true; U.Fs9F4M#  
"9#hk3*GqX  
RN2z/F Uf  
for(int i=0;i<nStartPos.length;i++) %F87"v~  
{ re fAgS!=q  
if(!fileSplitterFetch.bDownOver) `4,]Mr1b  
{ ?!u9=??  
breakWhile = false; ~cf)wrP  
break; XZ"oOE0=  
} ao"Z%#Jb~  
} e\._M$l  
if(breakWhile) l% p4.CX  
break; "8 ?6;!,  
I2gSgv%  
mGo NT  
//count++; N}Or+:"O:q  
//if(count>4) LX}|%- iv  
// siteStop(); g,B@*2Uj  
} TVVu_ib  
k- exqM2x=  
Of#"nu  
System.err.println("文件下载结束!"); \[ W`hhJ  
} 1ZXRH;J40  
catch(Exception e){e.printStackTrace ();} I5E5,{  
} m4^VlE,`Dh  
[$M l;K  
rIX 40,`  
//获得文件长度 nv3TxG  
public long getFileSize() !iAZEOkRR  
{ ceLr;}?Ws  
int nFileLength = -1; $#_^uWN-M  
try{ bd3>IWihp  
URL url = new URL(siteInfoBean.getSSiteURL()); tPDB'S:&3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qc3?Aplj  
httpConnection.setRequestProperty("User-Agent","NetFox"); +!t *LSF  
0Qg%48u  
!v*#E{r"g=  
int responseCode=httpConnection.getResponseCode(); bBQHxH}vi  
if(responseCode>=400) PAiVUGp5[  
{ y*8;T v|  
processErrorCode(responseCode); [n +(  
return -2; //-2 represent access is error  <JZa  
} 4VzSqb  
8g/r8u~  
we?t/YB=  
String sHeader; VKi3z%kwK  
hG3RZN#ejq  
aX~' gq>  
for(int i=1;;i++) ltd'"J/r  
{ "H{#ib_c_  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~5Rh7   
//Utility.log(in.readLine()); l> >BeZ  
sHeader=httpConnection.getHeaderFieldKey(i); l`];CALA4  
if(sHeader!=null) &HJ~\6r\  
{ Kw>gg  
if(sHeader.equals("Content-Length")) OmP(&t7  
{ 2aQ}| `  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Vb2")+*:  
break; (7v`5|'0  
} .sUL5`  
} F#{ PJ#  
else A3zNUad;  
break; 1z[blNs&  
} <JJi  
} P q( )2B  
catch(IOException e){e.printStackTrace ();} ,@2d4eg 4  
catch(Exception e){e.printStackTrace ();} \y/+H  
QLTE`t5w3'  
WTh|7&  
Utility.log(nFileLength); v aaZ  
nzu 3BVv  
Mq,_DQ  
return nFileLength; *-9b!>5eD  
} ?r~](l   
Z8Clm:S  
i@d@~M7/  
//保存下载信息(文件指针位置) 4HDQj]z/  
private void write_nPos() "i*Gi \U  
{ k)USLA  
try{ ,K[B/tD{j  
output = new DataOutputStream(new FileOutputStream(tmpFile)); b;Im +9&  
output.writeInt(nStartPos.length); /7zy5  
for(int i=0;i<nStartPos.length;i++) **O4"+Xi8  
{ AuYi$?8|5  
// output.writeLong(nPos); k07) g:_  
output.writeLong(fileSplitterFetch.nStartPos); Bj7\{x,?  
output.writeLong(fileSplitterFetch.nEndPos); z*>CP  
} f1>^kl3@P  
output.close(); PX'I:B]x*  
} Y<.F/iaH  
catch(IOException e){e.printStackTrace ();} XT_BiZ%l5O  
catch(Exception e){e.printStackTrace ();} et]*5Y6  
} ikRIL2Y  
@;,O V&XYn  
Fk(0q/b  
//读取保存的下载信息(文件指针位置) c\4n7m,y  
private void read_nPos() .^.UJo;4G  
{ 1y"37;x  
try{ U w`LWG3T  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y!!+IeReS  
int nCount = input.readInt(); Da-(D<[0  
nStartPos = new long[nCount]; W@$p'IBwm  
nEndPos = new long[nCount]; #CQ>d8&  
for(int i=0;i<nStartPos.length;i++) khv!\^&DD  
{ X0Oq lAw  
nStartPos = input.readLong(); ^Q:K$!  
nEndPos = input.readLong(); Em"X5>;4  
} Eq<#pX6  
input.close(); f|^f^Hu:{  
} b);}x1L.T  
catch(IOException e){e.printStackTrace ();} xf]4!zE  
catch(Exception e){e.printStackTrace ();} (kuZS4Af  
} -% f DfjP  
eu:_V+  
"\=_- `  
private void processErrorCode(int nErrorCode) 1aT$07G0  
{ YYvs~?bAy  
System.err.println("Error Code : " + nErrorCode); P*T)/A%4  
} +Ae.>%}  
4 z`5W,  
u ?Xku8 1l  
//停止文件下载 O46/[{p+8  
public void siteStop() ,`7GI*Vq  
{ >PJ-Z~O'   
bStop = true; I.<#t(io  
for(int i=0;i<nStartPos.length;i++) 5~X%*_[],  
fileSplitterFetch.splitterStop(); M#>GU<4"  
FT enXJ/c  
rh l5r"%  
} J@TM>R  
} yEny2q}  
//负责部分文件的抓取  e.GzGX  
**FileSplitterFetch.java ]xG4T>S  
*/ %dU}GYL_  
package NetFox; w g1pt1 `  
'x0t, ;g  
Z9D4;1  
import java.io.*; FTfA\/tl(;  
import java.net.*; ZkJM?Fzq  
-CrZ'k;4  
zef,*dQY   
public class FileSplitterFetch extends Thread { K0g:Q*J-  
<X |h *  
~e+w@ lK  
String sURL; //File URL h<.[U $,  
long nStartPos; //File Snippet Start Position kI'A` /B l  
long nEndPos; //File Snippet End Position 9gg,Dy  
int nThreadID; //Thread's ID bZXNo  
boolean bDownOver = false; //Downing is over SA1/U  
boolean bStop = false; //Stop identical t>2^!vl  
FileAccessI fileAccessI = null; //File Access interface ks;wc"k"  
sJ/e=1*  
,9qB}HG  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V2,WP  
{ c1J)yv1y  
this.sURL = sURL; %6'D!H?d  
this.nStartPos = nStart; BfT,  
this.nEndPos = nEnd; H@ms43v\  
nThreadID = id; I)6Sbt JV^  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <\g&%c,   
} ?ljod6  
*h:EE6|  
w WU_?Dr_~  
public void run() f](uc(8Z  
{ Q; /F0JDH  
while(nStartPos < nEndPos && !bStop) {7>CA'>  
{ @a\SR'8  
~!F4JRf  
y9li<u<PF  
try{ Q'% o;z*  
URL url = new URL(sURL); s@LNQ|'kO  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -==qMrKP  
httpConnection.setRequestProperty("User-Agent","NetFox"); (iOCzZ6S  
String sProperty = "bytes="+nStartPos+"-"; >Ryss@o  
httpConnection.setRequestProperty("RANGE",sProperty); H#6^-6;/  
Utility.log(sProperty); l\;mP.!  
aiZo{j<6  
Df~p 'N-$  
InputStream input = httpConnection.getInputStream(); mv*T=N8fC  
//logResponseHead(httpConnection); MlK`sH6  
Gj19KQ1G  
,i?!3oLT  
byte[] b = new byte[1024]; C'czXZtn  
int nRead; ioNa~F&  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vt=(2d5:p  
{ )_ ^WpyzF1  
nStartPos += fileAccessI.write(b,0,nRead); /rxltF3  
//if(nThreadID == 1) Lp`<L-s  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @" 0tW:  
} D5!K<G?-K  
$7n#\h  
BU:Ecchbr  
Utility.log("Thread " + nThreadID + " is over!"); R mW fV  
bDownOver = true;  Q A)9  
//nPos = fileAccessI.write (b,0,nRead); [j}7@Mr`\  
} B >u,)  
catch(Exception e){e.printStackTrace ();} >=~Fo)V!(V  
} 4l ZJb  
} KT];SF ^Y  
5+bFy.UW  
?D(FNd  
//打印回应的头信息 e-iYJ?  
public void logResponseHead(HttpURLConnection con) U8K &Q4^  
{ *hZ~i{c,7  
for(int i=1;;i++) >{ECyh;  
{ 4", )zDk  
String header=con.getHeaderFieldKey(i); G&@-R{i  
if(header!=null) *"ykTqa  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L7Qo-  
Utility.log(header+" : "+con.getHeaderField(header)); pymx\Hd,  
else WbQhl sc:  
break; 13.{Y)  
}  nOoKGT  
} q8?= *1g  
8B*E+f0  
"J P{Q  
public void splitterStop() t&R!5^R  
{ Gg}5$||^C  
bStop = true; hGed/Yr  
} .'5'0lR5  
!K3i-zY  
_\,rX\  
} pxw{  
N<aB)</  
+R "AA_A?  
/* #Rin*HL##  
**FileAccess.java 1Q&cVxA"\  
*//文件访问(定位,写) %"l81z  
package NetFox; _kn]#^ucCe  
import java.io.*; -l-AToO4  
N@cMM1  
jOBY&W0r  
public class FileAccessI implements Serializable{ x*unye7  
PM~bM3Ei  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q&u>7_, Du  
RandomAccessFile oSavedFile; ,dHP`j ?  
long nPos; *-9#/Cp  
[urH a  
J3H.%m!V  
public FileAccessI() throws IOException C0\%QXu  
{ X$BXT  
this("",0); UskZ%J  
} 5{')GTdX>  
TT|-aS0l(u  
7}<Sg  
public FileAccessI(String sName,long nPos) throws IOException myD{sE2A  
{ 5\VxXiy 0  
oSavedFile = new RandomAccessFile(sName,"rw"); 65lOX$*{-  
this.nPos = nPos; +yth_9  
oSavedFile.seek(nPos); ha_@Yqgh  
} kfVZ=`p}  
9U]pH%.9  
q;p.wEbr4U  
public synchronized int write(byte[] b,int nStart,int nLen) DWuRJ  
{ {U(Bfe^a,  
int n = -1; ]X*YAPv  
try{ GL/  KB  
oSavedFile.write(b,nStart,nLen); 6%>/og\%  
n = nLen; 'w}p[(  
} _]P a>8X*  
catch(IOException e) Wt(Kd5k0'2  
{ -zprNQW  
e.printStackTrace (); }gCG&7C  
} )eECOfmnZ  
ja?s@Y}-9s  
T 4eWbNSs  
return n; 7 xUE,)?  
} 02,W~+d1  
GN0duV  
$iwIF7,\P  
} 6Hda]y  
^=k {~  
O5O.><RP  
/* L/)B}8m\  
**SiteInfoBean.java vuZf#\zh}  
*/ u-kZW1wrQ  
package NetFox; xLZ bU4  
b]w[*<f?  
G&jZ\IV  
public class SiteInfoBean { n_J5zQJ  
E.9^&E}PG  
|e:rYLxm:  
private String sSiteURL; //Site's URL AO $Wy@  
private String sFilePath; //Saved File's Path w?_`/oqd|  
private String sFileName; //Saved File's Name ac|/Y$\w  
private int nSplitter; //Count of Splited Downloading File w [L&*  
zXjw nep  
'=p?  
public SiteInfoBean() w]}f6VlEl  
{//nSplitter的缺省值为5 #v+;:  
//default value of nSplitter is 5 k1 RV'  
this("","","",5); ZB$NVY  
} 8A!'I<S1  
]hL:33  
F*,5\s<  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )%t7\1)B3  
{ {l@WCR  
sSiteURL= sURL; T=>vh*J  
sFilePath = sPath; }1Z6e[K?  
sFileName = sName; EWO /u.z  
this.nSplitter = nSpiltter; n7S; Xve#  
 ni<[G0#T  
AX K95eS  
} >4M<W4  
p_r4^p\  
E?_ zZ2  
public String getSSiteURL() 9$wAm89  
{ !?b/-~o7S  
return sSiteURL; WGPD8.  
} \ FXp*FbQ  
#N$9u"8C  
ZJvo9!DL|  
public void setSSiteURL(String value) R(`]n!V2  
{ ,\x$q'  
sSiteURL = value; N8QH*FX/F1  
} Sz)b7:  
}#bZ8tm&  
-"tY{}z  
public String getSFilePath() b`zET^F  
{ &Sa~/!M  
return sFilePath; <]'|$8&jY  
} 7"a4/e;^  
+99Bi2H}o  
G1[(F`t>  
public void setSFilePath(String value) ai9  
{ 8)?_{  
sFilePath = value; c=aO5(i0  
} yV2e5/i  
| k}e&Q_/G  
tah }^  
public String getSFileName() R;'?;I  
{ zi.mq&,]R  
return sFileName; TzY *;  
} &mdB\Y?^  
NWaO_sm  
HU9p !I.  
public void setSFileName(String value) Fv@tD4I>  
{ ](nH{aY!  
sFileName = value; yzg9I  
} (!-;T  
}DHUTP2;yz  
63C(Tp"  
public int getNSplitter() X  Ny Y$  
{ +4HlRGH  
return nSplitter; x=vK EyS@  
} 70=(. [^+  
T]uKH29.%  
FJF3B)Va|  
public void setNSplitter(int nCount) 4|=vxJ  
{ om>VQ3  
nSplitter = nCount; _Fxe|"<^  
} dE GX3 -  
} bs P6\'\4  
:G0+;[?N  
Q.1XP  
/* ^}hZ'<PK  
**Utility.java 3a9u"8lG  
*/ LyV#j>gD  
package NetFox; cyBW0wV1  
p {?}g'  
#@E(<Pu4`  
public class Utility { g&kH'fR8  
=1IEpxh%  
ee^4KKsh\  
public Utility() kU1 %f o  
{ :l;,m}#@  
!?6.!2  
NZfd_? 3  
} { Hr>X  
\6i 9q=  
//线程睡眠 hR0]8l|  
public static void sleep(int nSecond) G>JxIrN0  
{ ]`K[W&  
try{  tI'e ctn  
Thread.sleep(nSecond); DP0Z*8Ia  
} ,[^o9u uB  
catch(Exception e) %xHu,*  
{ 6# R;HbkO  
e.printStackTrace (); )Yrr%f`\  
} tpE3|5dZF  
} "~Us#4>  
bje' Oolc  
//日志 @YsL*zw  
public static void log(String sMsg) .C6gl]6y@  
{ pIL`WE1'  
System.err.println(sMsg); w2' 3S#nZ  
} L^&do98  
eZ[#+0J  
nMeSCX  
public static void log(int sMsg)  r^e-.,+  
{ } cRi A  
System.err.println(sMsg); =g1D;  
} ]2g5Ka[>w  
}  POkXd^pI  
WI%zr2T  
omr:C8T>  
/* @i;LZa  
**TestMethod.java N c9<X  
*/ S|tA[klh  
package NetFox; bl6':m+  
N <ja6Ac  
DM+sjn  
public class TestMethod { 4{c`g$j>  
u)wu=z8  
Z(#XFXd  
public TestMethod() }6F_2S3c  
{ ///xx/weblogic60b2_win.exe *vEU}SxRuv  
try{ ^Jc$BMaVg  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hn*}5!^  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'cWlY3%t  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3XMBu*  
fileFetch.start(); jqV)V>M.  
} Tey,N^=ek  
catch(Exception e){e.printStackTrace ();} i G?w;  
g9RzzE!  
ufHuI*  
} nI((ki}v  
30wYc &H  
\k2C 5f  
public static void main(String[] args) f]O5V$!RuE  
{ x0N-[//YV  
new TestMethod(); (Q*2dd>  
} %`t]FV^#  
} 3Y.d&Nz  
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