http断点续传简单实现（java)

/* &)jBr^x#>  
**SiteFileFetch.java qxS=8#-`(  
*/ 7<{g+Q~7*  
package NetFox; p!qV!:  
import java.io.*; Ip#BR!$n  
import java.net.*; \a\-hm  
U9k;)fK  
`K -j  
public class SiteFileFetch extends Thread { -*xm<R],  
g}>Sc=e<  
]D(!ua5|x`  
SiteInfoBean siteInfoBean = null; //文件信息Bean \Tq !(]o^  
long[] nStartPos; //开始位置 B#RBR<MFC  
long[] nEndPos; //结束位置 
#OlU
|I  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 y/U(v"'4U  
long nFileLength; //文件长度 g'2'K  
boolean bFirst = true; //是否第一次取文件 kA3nhBH  
boolean bStop = false; //停止标志 6*yt^[W  
File tmpFile; //文件下载的临时信息 q@K8,=/.#  
DataOutputStream output; //输出到文件的输出流 !RX\">z  
k?r-%oJ7  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） n^F:p*)Q%  
public SiteFileFetch(SiteInfoBean bean) throws IOException hP1}Do  
{ 1aEM&=h_W  
siteInfoBean = bean; pxm{?eBz  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); %`*`HU#X  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); R^8L^8EL  
if(tmpFile.exists ()) D7q%rO|F'  
{ >6fc`3*!  
bFirst = false; A4;EtW+F  
read_nPos(); ['9awgkr/  
} Py^ _::  
else k?(x}IZdG  
{ Dn{ hU$*  
nStartPos = new long[bean.getNSplitter()]; )qXl8HI  
nEndPos = new long[bean.getNSplitter()]; .Up\ 0|b  
} ^{z
@=o<o  
VI83 3  
Xvy3D@o  
mOiA}BGw  
} l!r2[T]I@7  
5:3%RTLG  
SvR:tyF  
public void run() 3FWl_d~uD  
{ =W+ h.?  
//获得文件长度 /u hA\m(  
//分割文件 uu08q<B5b)  
//实例FileSplitterFetch tE&@U$0>o  
//启动FileSplitterFetch线程 ""AP-7  
//等待子线程返回 Q[g>ee  
try{ w[`2t{^j  
if(bFirst) Po+I!TL'  
{ y3!r;>2k=  
nFileLength = getFileSize(); Fk&W*<}/;  
if(nFileLength == -1) i%~^3/K  
{ )=,%iL-  
System.err.println("File Length is not known!"); z4qw*. 5  
} n*%o!=  
else if(nFileLength == -2) rHS;wT  
{ Zp5;=8wa;  
System.err.println("File is not access!"); >lyX";X#  
} NBLiwL37{  
else W lDcKY  
{ sZ~q|}D-  
for(int i=0;i<nStartPos.length;i++) ;Y/{q B!  
{ um/2.Sn>  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ~!PAs_O  
} SZ/}2_;  
for(int i=0;i<nEndPos.length-1;i++) Xr?(w(3  
{ <5Ft3sd  
nEndPos = nStartPos[i+1]; U[l7n3Y=  
} PwF 1Pr`r  
nEndPos[nEndPos.length-1] = nFileLength; >F@qFPN]  
} 4 h}03 oG  
} +TA'P$j  
\BIa:}9O  
PKDzIA~T  
//启动子线程 x#wkODLqi  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];
5U%J,W  
for(int i=0;i<nStartPos.length;i++) b=V"$(Q  
{ ,7` /D  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X5s.F%Np!  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &ZkY9XO  
nStartPos,nEndPos,i); JCL+uEX4S  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'brt?oZ%  
fileSplitterFetch.start(); !v^{n+  
} U<
T.o0s=  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )Dg;W6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); oJ r&9.S  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0?DD!H)&w  
nEndPos = " + nFileLength); 5AX AIPn)  
// fileSplitterFetch[nPos.length-1].start(); |I; tBqN{u  
/>wM#)o2  
HIK"Ce  
//等待子线程结束 )<J|kC\r6c  
//int count = 0; U[4Xo&`  
//是否结束while循环 ll]MBq  
boolean breakWhile = false; KKrLF?rc  
:5Y yI.T  
A&HN7C%X  
while(!bStop) C*+gQeK  
{ L5+X&  
write_nPos(); )@vhqVv?  
Utility.sleep(500); &sFEe<  
breakWhile = true; =[N=mC  
x,CTB  
*u?QO4>  
for(int i=0;i<nStartPos.length;i++) 2#<)-Cak  
{ R?%J   
if(!fileSplitterFetch.bDownOver) h=:*cqp4  
{ AXnuXa(j  
breakWhile = false; FU{$oCh/5  
break; *wH.]$  
} I:~KF/q  
} /G{;?R  
if(breakWhile) {B!LhvYAH  
break; 'H19@b5rx  
K;:_UJ>t  
uX.^z
g]}%  
//count++; 2)iwAu   
//if(count>4) +ESEAi91  
// siteStop(); M
2pe*z  
}
C:*=tD1  
%anY'GK
 
GnX+.uQL|  
System.err.println("文件下载结束！"); jTR>H bh  
} 3MmpB9l#H  
catch(Exception e){e.printStackTrace ();} (D.B'V#>  
} :,@"I$>*/  
q=EHB5!q  
A`'k5uG  
//获得文件长度 `u<\ 4&W  
public long getFileSize() G_vcuCHm  
{ _1c0pQ^}3  
int nFileLength = -1; ?%|w?Fdx-  
try{ _u[2R=h  
URL url = new URL(siteInfoBean.getSSiteURL()); >,Z[IAU.x5  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9\QeH'A  
httpConnection.setRequestProperty("User-Agent","NetFox"); uwL^Tq}Yh  
cuw 7P  
ax.;IU  
int responseCode=httpConnection.getResponseCode(); %>z4hH,  
if(responseCode>=400) {^5LolCCH  
{ Wz8MV -D  
processErrorCode(responseCode); #Nv^F  
return -2; //-2 represent access is error kFRl+,bi~  
} s%&/Zt  
KT4h3D`,  
}Wk^7[Y  
String sHeader; O(R1D/A[  
jkQ%b.a  
y[D8rFw  
for(int i=1;;i++) z[cs/x  
{ c\Z.V*o  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^v
j}  
//Utility.log(in.readLine()); s~z~9#G(6  
sHeader=httpConnection.getHeaderFieldKey(i); B~CdY}UTsj  
if(sHeader!=null) & t.G4  
{ \80W?9qj  
if(sHeader.equals("Content-Length")) r_x|2 AoO  
{ /wR,P  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3)6TnY/u6{  
break; u~C,x3yr  
} &'V1p4'  
} j`D%Wx_  
else F3?PlH:Y  
break; kS7`g A  
} f-!P[6bY  
} wv7XhY}  
catch(IOException e){e.printStackTrace ();} +55+%oGl  
catch(Exception e){e.printStackTrace ();} f@j)t%mh  
_.{I1*6Y2  
qk{+Y  
Utility.log(nFileLength); @W1F4HYds  
m8T< x>  
JK/gq}c  
return nFileLength; 9n#lDL O  
} t@;r~Sb  
5r)]o'?s  
d:L|BkQ7*  
//保存下载信息（文件指针位置） *y0=sG1+D  
private void write_nPos() R1/h<I:  
{ F"ua`ercI  
try{ n^t!+  
output = new DataOutputStream(new FileOutputStream(tmpFile)); tKX+eA]  
output.writeInt(nStartPos.length); Hrg~<-.La  
for(int i=0;i<nStartPos.length;i++) Gp9:#L!  
{ ;:]#Isq  
// output.writeLong(nPos); (a9>gLI0  
output.writeLong(fileSplitterFetch.nStartPos); A<U9$"j9J  
output.writeLong(fileSplitterFetch.nEndPos); rqi/nW  
} FK+`K<  
output.close(); S8dX8,qg  
} d7]~t|  
catch(IOException e){e.printStackTrace ();} }0oVIr  
catch(Exception e){e.printStackTrace ();} tW -f_0a.  
} iD${7 _  
X{u\|e{  
!qe:M]C'l  
//读取保存的下载信息（文件指针位置） Wb%t6N?  
private void read_nPos() V{{Xz:  
{ Pm/Rc  
try{ u85dG7  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cuoZ:
Wh  
int nCount = input.readInt(); '* eeup  
nStartPos = new long[nCount]; b6?&h:{k  
nEndPos = new long[nCount]; K(3_1*
e  
for(int i=0;i<nStartPos.length;i++) T!%J x.^  
{ | zyO;  
nStartPos = input.readLong(); 0@tN3u?dx  
nEndPos = input.readLong(); v;o/M6GL5  
} MJM<  
input.close(); *~\R0ddz  
} XQPlhpcv  
catch(IOException e){e.printStackTrace ();} _*.ImD  
catch(Exception e){e.printStackTrace ();} )gHfbUYS  
} mHF?t.y  
/Y`u4G()  
'/'dg5bfV  
private void processErrorCode(int nErrorCode) m>9j dsqB  
{ od-yVE
&  
System.err.println("Error Code : " + nErrorCode); 2r"J"C  
} 4de:hE   
!Z!X]
F-fY  
j[${h,p?  
//停止文件下载  va[r~  
public void siteStop() 928uGo5  
{ l{mC|8X  
bStop = true; 8)ykXx/f@  
for(int i=0;i<nStartPos.length;i++) Pk{%2\%&2  
fileSplitterFetch.splitterStop(); d#CAP9n;
'  
^N&@7s  

X]4j&QB  
} WD>z  
} dvu8V_U  
//负责部分文件的抓取  \RS ,Y  
**FileSplitterFetch.java t`")Re_j  
*/ eXAJ%^iD  
package NetFox; Q#5~"C  
0^83:C ^{  
\h@3dJ4  
import java.io.*; rK[;wD<  
import java.net.*; tUk)S  
Bp-e< :  
a7}O.NDf  
public class FileSplitterFetch extends Thread { yHf:/8Z  
~0Z.,p_  

KA? J:  
String sURL; //File URL lw43|_'G-t  
long nStartPos; //File Snippet Start Position %j/}e>$"Nk  
long nEndPos; //File Snippet End Position lSG]{  
int nThreadID; //Thread's ID a];1)zVA6  
boolean bDownOver = false; //Downing is over Ku?1QDhrF*  
boolean bStop = false; //Stop identical ;~GBD]  
FileAccessI fileAccessI = null; //File Access interface 1<;VD0XX  
slQEAqG)B  
UuCRQNH  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2QgD<  
{ ^Rb*m
I  
this.sURL = sURL; >0JCu^9  
this.nStartPos = nStart; ;R]~9Aan  
this.nEndPos = nEnd; k`BS{,=  
nThreadID = id; _t>[gB,  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d*_rJE}B  
} ^#!\VGnL  
y&(pt!I  
.Vrl:  
public void run() OCELG~  
{ <-DQ(0xg  
while(nStartPos < nEndPos && !bStop) 9p,PWA  
{ C@WdPjxj  
o8X? 1  
?&-$Zog  
try{ LSrKi$   
URL url = new URL(sURL); 0"{-<Wot}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \U>|^$4 #5  
httpConnection.setRequestProperty("User-Agent","NetFox"); G_`Ae%'h  
String sProperty = "bytes="+nStartPos+"-"; |RL\2j|  
httpConnection.setRequestProperty("RANGE",sProperty); _+OCI%=:  
Utility.log(sProperty); Zi}jf25  
E:y^= Y  
n.XgGT=L  
InputStream input = httpConnection.getInputStream(); -TS
5g1  
//logResponseHead(httpConnection); ,AH2/^:%c  
q[(1zG%NbA  
05Q4$P  
byte[] b = new byte[1024]; |W*5<2Q9  
int nRead;  I)MRAo  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {f\{{JJ]  
{ %c@PTpAM  
nStartPos += fileAccessI.write(b,0,nRead); 3e9UDN2  
//if(nThreadID == 1) m=25HH7enb  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^% L;FGaA  
} hi/Z>1ZOX  
Z^Yy sf  
Xp9] 9H.  
Utility.log("Thread " + nThreadID + " is over!"); tgj5l#P  
bDownOver = true; LkWY6 ?$U  
//nPos = fileAccessI.write (b,0,nRead); @0V4$OoFl  
} &g~NkJc0c  
catch(Exception e){e.printStackTrace ();} LqLhZBU9  
} F*_+k  
} .,f]'!5  
Z7I
\\M  
&W3Hj$>  
//打印回应的头信息 49e
hj1Se  
public void logResponseHead(HttpURLConnection con) V\AY=u  
{ ZiPz~G0[^  
for(int i=1;;i++) \Vpv78QF;  
{ $Gcj
m~  
String header=con.getHeaderFieldKey(i); *z};&UsF{  
if(header!=null) ]cM8TT  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B`YD>oCN  
Utility.log(header+" : "+con.getHeaderField(header)); CwD=nT5`  
else V
jd(Z  
break; {Wndp%  
} j`#H%2W\;  
} %Fx^"  
yqH9*&KH{  
4X!4S6JfB  
public void splitterStop() ^r,0aNzAs  
{ |;\pAZ2  
bStop = true; ..5.":  
} MnlD87x@X  
b~2LD3"3  
6z]y =J  
} WD1>{TSn  
1'P4{T0 [  
bokr,I3  
/* 0oZZLi  
**FileAccess.java z4(`>z2a  
*//文件访问(定位，写) 2O- 4x  
package NetFox; {0%  
import java.io.*; q/Zs]Gz  
nzZs2  
9z`72(  
public class FileAccessI implements Serializable{ 8@b`a]lgrd  
putRc??o;  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ui-]%~  
RandomAccessFile oSavedFile; x.$cP  
long nPos; ttls.~DG  
wp83E,  
i(;.Y  
public FileAccessI() throws IOException 6uTC2ka[&R  
{ %`~+^{Wp  
this("",0); x4h.WDT$  
} G9Noch9 g  
4Dy1M}7
 
@R<z=n"  
public FileAccessI(String sName,long nPos) throws IOException W.%p{wB|  
{ 9m)gp19YA  
oSavedFile = new RandomAccessFile(sName,"rw"); LG:d  
this.nPos = nPos; XpYd
|BvW  
oSavedFile.seek(nPos); X(BX+)YR  
} M!i*DU+SE  
*sau['Ha  
i6$HwRZm#  
public synchronized int write(byte[] b,int nStart,int nLen) L2_[M'  
{ Q}cti/  
int n = -1; olr-oi`4C  
try{ Yf
/e(nV  
oSavedFile.write(b,nStart,nLen); +43~4_Oj  
n = nLen; ^Ku]8/ga  
} E;9J7Q 4  
catch(IOException e) C/QrkTi=  
{ $|@pY| f  
e.printStackTrace (); a:OMI  
} n^b CrvD  
\RtFF  
@eutp`xoT\  
return n; >?_}NZ,y  
} y^[t3XA6Q  
9_4(}|"N|  
3t9CN )*  
} cucmn*o?  
V7`vLs-  
L8H:,} 2  
/* 1wH
6 hN,  
**SiteInfoBean.java ^>>9?  
*/ T1R~^x1  
package NetFox; ~]].i~EV(  
_CTg")0o  
ng~LCffpY  
public class SiteInfoBean { q/
Vl>t  
^)GaVL^"5  
fUfd5W1"  
private String sSiteURL; //Site's URL aOd|;Z  
private String sFilePath; //Saved File's Path KJv%t_4'F  
private String sFileName; //Saved File's Name !@wUARQ  
private int nSplitter; //Count of Splited Downloading File cK2;)
&U7  
Ux{0)"fj  
3)L#V .  
public SiteInfoBean() bBV03_*  
{//nSplitter的缺省值为5 q#I'@Jbj  
//default value of nSplitter is 5 iBtG@M  
this("","","",5); >56fa6=3@  
} "5z@A/Z/  
)v*k\:
Hw  
K
eB??1S  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /9,'.  
{ .'$8Hj;@  
sSiteURL= sURL; _ker,;{9C  
sFilePath = sPath; 7&/1K%x9;  
sFileName = sName; }s:3_9mE  
this.nSplitter = nSpiltter; *4LRdLMn  
/Oi(5?Jn  
Z{:;LC  
} RZKx!X4=q  
Z_edNf}|  
D(TG)X?  
public String getSSiteURL() N{ $?u  
{ 2+?W{
yAEi  
return sSiteURL; *D
XX*9 0  
} ?B$L'i[l  
F6{/iF  

I{ki))F  
public void setSSiteURL(String value) = Ezg3$%-  
{ xK)<763q>  
sSiteURL = value; M2RkrW#  
} )siWc_Z4  
Xit@.:a;  
BlZB8KI~  
public String getSFilePath() ~c] q:pU2  
{
r[T(R9k  
return sFilePath; _Pa@%/  
} tw=A] a*  
k.2GIc:5  
9;uH}j8sE  
public void setSFilePath(String value) u8<[Q]5  
{ 8~y
P?#p  
sFilePath = value; UjLq[,_!  
} :Ny[?jtc  
LFqY2,#i  
K"|~D0Qgo  
public String getSFileName() !syyOfu`}  
{ fAz4>_4  
return sFileName; NFtA2EMLu[  
} avM8-&h  
`HnZ{PKf  
6uKth mr  
public void setSFileName(String value) L+T'TC:  
{ :?LNP3}  
sFileName = value; {Rb;1 eYj  
} B u%
%O8  
t#8QyN  
.Y^3G7On  
public int getNSplitter() oM^vJ3  
{ F
V7'3f
Ia  
return nSplitter; -!mtL
aLw  
} Gc*=n*@^K  
DfU= i'R  
nk_X_y  
public void setNSplitter(int nCount) GA` bWl  
{ 64'QTF{D  
nSplitter = nCount; =
qoOr~  
} z
Hg=K /  
} 7HY8 F5Brx  
tS5J{j>T  
#G?#ot2o  
/* f*88k='\W  
**Utility.java (UhJ Pco"  
*/ }
EHL }Q  
package NetFox; BzH0"xq^  
_TmKn!Jw  
'vu]b#l3  
public class Utility { ` ~^My~f  
J%B
/(v`  
(x@J@ GP*  
public Utility() TuPD5-wB&  
{ F|/6;&*?M  
i `p1e5$  
7lAJ 0  
} 1Z;cb0:  
=sv?))b`  
//线程睡眠 g:xg ~H2  
public static void sleep(int nSecond) ZREy I(_  
{ {Y=k`t,  
try{ q4Bw5
~n  
Thread.sleep(nSecond); *?C8,;=2r  
} 0-aaLC~Z>  
catch(Exception e) #O,w{S  
{ 1:- M<=J?f  
e.printStackTrace (); J7oj@Or9  
} hR:i!  
} C+ Y;D:  
4 #KC\C  
//日志 ,'t&L]  
public static void log(String sMsg) d8R|0RZ  
{ iRcac[uV  
System.err.println(sMsg); C`3XOth  
} ^jd
tp  
'@WBq!p  
8 $H\b &u  
public static void log(int sMsg) fk6=;{  
{ 9!_LsQ\)  
System.err.println(sMsg); Z,\(bW qF  
} N%q{CYF6  
} =h=-&DSA  
`1Md1e:J  
>ifys)wg>  
/* 8'zfq ]g  
**TestMethod.java &U=_:]/  
*/ lX/7  
package NetFox; h
Cc%d$wVk  
W!kF(O NA  
'qo(GGC M  
public class TestMethod { Xt:j~cVA  
<
;>k[P'  
$Jn.rX0}$  
public TestMethod()  xiQc\k$  
{ ///xx/weblogic60b2_win.exe OEzSItAI/[  
try{ _Gb7n5p  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N>sT@ > )  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UUtSme  
SiteFileFetch fileFetch = new SiteFileFetch(bean); .wWf#bB  
fileFetch.start(); qC& xuu|  
} 4DP<)KX  
catch(Exception e){e.printStackTrace ();} OI:=>Bk  
0$Zh4Y  
FEopNDy@y  
} NU{eoqaT  
0pB'^Q{  
P@n rcgM.  
public static void main(String[] args) 3BLHd<  
{ t4~?m{
 
new TestMethod(); 2v4&'C  
} 5^l-3s?M  
} 2\O!vp>|-  
点击下载更多相关资料