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http断点续传简单实现(java)

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/* dfij|>:*0  
**SiteFileFetch.java D>LZP!  
*/ * iF]n2g:  
package NetFox; rl #p".4q  
import java.io.*; i*@< y/&'  
import java.net.*; TZY3tUx0|G  
l p(8E6  
AD|2q M))  
public class SiteFileFetch extends Thread { Yj6*NZ*  
SN1}xR$  
\Hn>oonph  
SiteInfoBean siteInfoBean = null; //文件信息Bean #g]vc_V  
long[] nStartPos; //开始位置 1*@'-mj  
long[] nEndPos; //结束位置 ;e1ku|>$  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 6I4oi@hZz  
long nFileLength; //文件长度 %>g3~yl  
boolean bFirst = true; //是否第一次取文件 T Kg aV;92  
boolean bStop = false; //停止标志 $7rq3y  
File tmpFile; //文件下载的临时信息 j'MO(ev  
DataOutputStream output; //输出到文件的输出流 UOxkO  
H*$jc\ dC  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 5 4L\Jx  
public SiteFileFetch(SiteInfoBean bean) throws IOException CnG+Mc^  
{ V{:A3C41  
siteInfoBean = bean; xUa{1!Y8  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 0 g?z&?  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); *%S"eWb  
if(tmpFile.exists ()) LC'{p  
{ XYZ4TeW\1  
bFirst = false; f7X6fr<  
read_nPos(); B4i!/@0s  
} Yd#/1!A7u  
else {l/-LZ.  
{ 2kIa*#VOJ  
nStartPos = new long[bean.getNSplitter()]; 7Z-O_h3;)@  
nEndPos = new long[bean.getNSplitter()]; Vv.|br`;}  
} R' !  
/XzH?n/{R  
,Q HU_jt  
u (em&M  
} 9 mmCp&~Z  
ucG@?@JENm  
6 1F(<!  
public void run() 93` AWg/T  
{ 3v5%y '  
//获得文件长度 X;"Sx#U  
//分割文件 >JC  
//实例FileSplitterFetch iC9 8_o_9  
//启动FileSplitterFetch线程 f;xkT  
//等待子线程返回 y&?6FY  
try{ SBIj<Yy]  
if(bFirst) Zw ^kmSL"  
{ !AKg m'Nw  
nFileLength = getFileSize(); 3G`aHTWk  
if(nFileLength == -1) z6w3"9Um  
{ ).sRv6/c  
System.err.println("File Length is not known!"); a{qM2P(S  
} =A!@6Nw  
else if(nFileLength == -2) .`4{9?bR  
{ g!+| I  
System.err.println("File is not access!"); + EGD.S{  
} w (/aiV  
else #w\~&0  
{ YQ6f}O  
for(int i=0;i<nStartPos.length;i++) @!yMIM%P  
{ 7:)n$,31FW  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); s3R(vd  
} [`c^ 4 E  
for(int i=0;i<nEndPos.length-1;i++) n1VaLD  
{ BE_ay-  
nEndPos = nStartPos[i+1]; ]jmL]Ny^  
} |>tKq;/  
nEndPos[nEndPos.length-1] = nFileLength; RkBb$q9F]  
} z2QP)150  
} TTt#a6eJ  
d [V;&U  
2gq9k}38  
//启动子线程 ~XWQhIAM4  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Te}8!_ohyC  
for(int i=0;i<nStartPos.length;i++) VI'hb'2  
{ /5:bvg+  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), INi]R^-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q^e}?v%=%3  
nStartPos,nEndPos,i); zBk'{[y9L  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WzF !6n!h  
fileSplitterFetch.start(); fvF?{k>~}  
}  s8rE$  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I$0)Px%z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dK2p7xo  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @>)r}b  
nEndPos = " + nFileLength); %]8qAtV^3j  
// fileSplitterFetch[nPos.length-1].start(); 7TDy.]  
U}PiY"S<  
,}))u0q+:  
//等待子线程结束 Hr]h J c  
//int count = 0; 1PP $XJtyD  
//是否结束while循环 X7i/fm{l'  
boolean breakWhile = false; 8peDI7[|  
( m:Zk$  
i2&ed_h<?  
while(!bStop) 3 "Q=Vl"  
{ j(k: @  
write_nPos(); GrAujc5|  
Utility.sleep(500); (3 #Cl 1]f  
breakWhile = true; .b-f9qc=  
OI0;BBZ  
*i- _6s  
for(int i=0;i<nStartPos.length;i++) L.1_(3NG  
{ EVVP]ND  
if(!fileSplitterFetch.bDownOver) N.]qU d  
{ 8qu2iPOcZ  
breakWhile = false; }= 6'MjF]  
break; 0VGPEKRh  
} L_+k12lm  
} k'IYA#T6  
if(breakWhile) R@6zGZ1  
break; jlBanGs?  
i]|Yg$  
we;G]`@?  
//count++; wm$}Pch  
//if(count>4) 1I<rXY(a`  
// siteStop(); {6c2{@  
} r!HwXeEn/  
5c^Z/ Jl$c  
u a~CEs  
System.err.println("文件下载结束!"); 5KDGSo  
} ""1^k2fj  
catch(Exception e){e.printStackTrace ();} CFqJ/ ''  
} "E8zh|m o  
J]G?Rc  
2cqI[t@0  
//获得文件长度 &b?LP]   
public long getFileSize() `(f!*Ru@/z  
{ sM?MLB\Za  
int nFileLength = -1; %T)oCjM[\  
try{ kWe{r5C7  
URL url = new URL(siteInfoBean.getSSiteURL()); }2uI?i8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hvuIxqv!y  
httpConnection.setRequestProperty("User-Agent","NetFox"); %9M~f*  
0LfU=X0#7  
1Lg-.-V  
int responseCode=httpConnection.getResponseCode(); E !a|Xp  
if(responseCode>=400) HKqwE=NZ  
{ oA =4=`  
processErrorCode(responseCode); (A?H1 9  
return -2; //-2 represent access is error )~+e`q  
} kIGbG;"_  
LwK+:4$  
B:e @0049  
String sHeader; Xy@7y[s]  
g"?Y+j  
0MkSf*  
for(int i=1;;i++) 05spovO/'  
{ Wt=|  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XP1~d>j  
//Utility.log(in.readLine()); 8:#rA*Y  
sHeader=httpConnection.getHeaderFieldKey(i); rDQ!zlg>l  
if(sHeader!=null) +=mkCU  
{ xw3YK!$sIF  
if(sHeader.equals("Content-Length")) BWM YpZom  
{ +{/*z  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :LQ5 u[g$\  
break; Wa1, p  
} ec gtUb8K  
} 9:!gI|C  
else .%^]9/4  
break; ]miy/V }5  
} 2 OwV^-OG  
} N @#c,,  
catch(IOException e){e.printStackTrace ();} EM/@T}  
catch(Exception e){e.printStackTrace ();} Cz W:L&t  
T<L^N+<,{N  
m@Qt.4m%g  
Utility.log(nFileLength); KMV=%o  
2Y>~k{AN%  
$YXMI",tt<  
return nFileLength; 7 As|Ns`  
} v9D22,K-  
x&`~R>5/  
h[?O+Z^  
//保存下载信息(文件指针位置) BA:yQ  
private void write_nPos() =r.mlc``W  
{ =Me5ft w  
try{ dTL5-@  
output = new DataOutputStream(new FileOutputStream(tmpFile)); w~ ;I7:  
output.writeInt(nStartPos.length); 2<][%> '  
for(int i=0;i<nStartPos.length;i++) Hzhceeh_+  
{ X5]TY]  
// output.writeLong(nPos); Kv rX{F=  
output.writeLong(fileSplitterFetch.nStartPos); ) gzR=9l  
output.writeLong(fileSplitterFetch.nEndPos); AxZD-|.  
} q\q=PB6r  
output.close(); `xc^_781\  
} $&=p+  
catch(IOException e){e.printStackTrace ();} +*n-<x5"  
catch(Exception e){e.printStackTrace ();} R.s^o]vT  
} `g_"GE  
yCXrVN:`,  
{ K _kPgKS  
//读取保存的下载信息(文件指针位置) r,]#b[:.s|  
private void read_nPos() *1'`"D~  
{ HJC(\\~  
try{ |w*R8ro_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _oB_YL;,*  
int nCount = input.readInt(); z**hD2R!  
nStartPos = new long[nCount]; kip`Myw+  
nEndPos = new long[nCount]; e*  
for(int i=0;i<nStartPos.length;i++) /R LI,.%  
{ ;@nFVy>U  
nStartPos = input.readLong(); 9ktEm|F3  
nEndPos = input.readLong(); v6GsoQmA   
} '&FjW-`" G  
input.close(); ]}mxY vu_i  
} vNW jH!'  
catch(IOException e){e.printStackTrace ();} @f!AkzI  
catch(Exception e){e.printStackTrace ();} zD)pF1,7:8  
} phYDs9-K  
>m'x8xB=  
=9G;PVk|  
private void processErrorCode(int nErrorCode) QR> Y%4 ;h  
{ @cq`:_.[  
System.err.println("Error Code : " + nErrorCode); U{ ;l0 2S  
} MDRe(rF=  
+ zkm(  
}sxn72,  
//停止文件下载 %@R~DBS  
public void siteStop() J.R AmU<  
{ 4.K'\S  
bStop = true; eV6o3u:9  
for(int i=0;i<nStartPos.length;i++) [WB{T3j  
fileSplitterFetch.splitterStop(); CkRX>)=py  
x3e]d$  
&,i~cG?  
} "%@uO)A /  
} [ B0K  
//负责部分文件的抓取 ,}C8;/V  
**FileSplitterFetch.java gor <g))\  
*/ @("}]/O V:  
package NetFox; M;Wha;%E"  
q9dLHi<1  
\NXQ  
import java.io.*; K` nJVc  
import java.net.*; HXJ9xkrr  
m]IysyFFK  
-)<m S  
public class FileSplitterFetch extends Thread { t#<KxwhcN  
"]t>ZT:OJ  
}`9`JmNM  
String sURL; //File URL gvnj&h.GV  
long nStartPos; //File Snippet Start Position o6?l/nJ  
long nEndPos; //File Snippet End Position 9b6!CNe!  
int nThreadID; //Thread's ID =Mhg  
boolean bDownOver = false; //Downing is over PaVO"y]C  
boolean bStop = false; //Stop identical b4 hIeBI\  
FileAccessI fileAccessI = null; //File Access interface 9.0WKcwg  
=p&sl;PsLw  
4w{-'M.B  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Yb=6C3l@  
{ wk 02[  
this.sURL = sURL; E '%lxr  
this.nStartPos = nStart; * Zd_ HJi  
this.nEndPos = nEnd; _2jw,WKr  
nThreadID = id; z};ZxN  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HR3_@^<7  
} v3JPE])/  
F$*3@Y  
j;2<-{  
public void run() n6d^>s9J  
{ *\LyNL(  
while(nStartPos < nEndPos && !bStop) ARx0zI%N  
{ JCQ:+eqt  
-NDi5i\  
$o^e:Y , a  
try{ lEfBe)7+  
URL url = new URL(sURL); i=8UBryr'e  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -3mgza  
httpConnection.setRequestProperty("User-Agent","NetFox"); rR!U;  
String sProperty = "bytes="+nStartPos+"-"; r]t )x*  
httpConnection.setRequestProperty("RANGE",sProperty); F^'v{@C  
Utility.log(sProperty); ?Bu}.0ku-$  
tF`MT%{Va  
6s,2NeVWa  
InputStream input = httpConnection.getInputStream(); Z5>V{o  
//logResponseHead(httpConnection); +{6`F1MO  
[A_r1g&_  
`{G?>z Fp  
byte[] b = new byte[1024]; /{DaPqRa  
int nRead; z{6 YC~  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O3ZM:,.  
{ >Zdi5') 5  
nStartPos += fileAccessI.write(b,0,nRead); hNO )~rt  
//if(nThreadID == 1) #` +]{4hR  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); & zgPN8u  
} _[1^s$  
4zzlazU  
E|,30Z+  
Utility.log("Thread " + nThreadID + " is over!"); (zmNa}-  
bDownOver = true; kr{)  
//nPos = fileAccessI.write (b,0,nRead); `Z8^+AMc  
} b8HE."*t  
catch(Exception e){e.printStackTrace ();} u0 BMyH  
} qsvpW%?aE  
} =43d%N  
M,JA;a, _  
K6(.KEW  
//打印回应的头信息 1$OVe4H1  
public void logResponseHead(HttpURLConnection con) bx7\QU+  
{ (!ZV9S  
for(int i=1;;i++) <c\]Ct  
{ -? Tz.y&  
String header=con.getHeaderFieldKey(i); 7&px+155  
if(header!=null) Q!x`M4   
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tO4):i1  
Utility.log(header+" : "+con.getHeaderField(header)); T\cR2ZT~  
else j Ii[  
break; O8$~*NFJf  
} Ft$^x-d  
} Nor`c+,4  
N Z)b:~a  
&PSTwZd  
public void splitterStop() yP%o0n/"x  
{ 55,=[  
bStop = true; 9H[/Tj-;  
} )"F5lOA6  
K{N%kk%F  
pEkOSG  
} E+Im~=m$  
_lNC<7+#h  
+.wT 9kFcc  
/* )+*{Y$/U  
**FileAccess.java }z?xGW/k  
*//文件访问(定位,写) 8Yxhd .  
package NetFox; &!6DC5  
import java.io.*; T|!D>l'  
Y!;gQeC  
0w'|d@*wV  
public class FileAccessI implements Serializable{ ;n` $+g:>  
pY, O_ t$  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^aT;aP^l  
RandomAccessFile oSavedFile; cP, ;Qbe  
long nPos; PlF!cr7:4  
ZX h~ 79  
 A<2I!  
public FileAccessI() throws IOException KCl &H  
{ hc6.#~i  
this("",0); @Mzz2&(d U  
} ^J0zXe -d  
[pr 9 $Jr  
&7fY_~)B  
public FileAccessI(String sName,long nPos) throws IOException T6,V  
{ % <^[j^j}o  
oSavedFile = new RandomAccessFile(sName,"rw"); QTeFR&q8  
this.nPos = nPos; 8i[".9}G\  
oSavedFile.seek(nPos); 6GY32\Ac  
} z;U LQ  
U%h7h`=F?  
70duk:Ri0  
public synchronized int write(byte[] b,int nStart,int nLen) qPqy4V. ;  
{ aN:HG)$@  
int n = -1; yB=C5-\F  
try{ v;Swo("  
oSavedFile.write(b,nStart,nLen); ^g70AqUc  
n = nLen; 8g.AT@ ,Q  
} 9^(HXH_f  
catch(IOException e) Y:rJK|m  
{ NoJUx['6  
e.printStackTrace (); I Jqv w  
} g)X7FxS,z  
HgYc@P*b  
&|s+KP|d  
return n; V;H d)v( j  
} _k6x=V;9g  
DakLD~H;  
i^/ eN  
} L7s>su|c(  
N&?T0Ge;  
lt{lHat1  
/* kV_#9z7%  
**SiteInfoBean.java Ft)t`E'%j  
*/ qo)Q}0  
package NetFox; j p!  
1]_?$)$T  
<"hb#Tn  
public class SiteInfoBean {  <V7SSm  
j.<:00<  
(W7;}gysh  
private String sSiteURL; //Site's URL i5.?g<.H  
private String sFilePath; //Saved File's Path eVZa6la"  
private String sFileName; //Saved File's Name S@9w'upd  
private int nSplitter; //Count of Splited Downloading File iJ,M-GHK  
YR?3 61FK  
$K+4C0wX`  
public SiteInfoBean() ,2RC|h^O,  
{//nSplitter的缺省值为5 2T//%ys=  
//default value of nSplitter is 5 g8LT7  
this("","","",5); \m(ymp<c`  
} Jq=00fcT+  
K5 5} Wi  
C(EYM$  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z\e>DdS  
{ XyvZ&d6(d  
sSiteURL= sURL; c9\B[@-q  
sFilePath = sPath; os}b?I*K  
sFileName = sName; y T[Lzv#  
this.nSplitter = nSpiltter; J"/ JRn  
5dg-d\ 6S  
UN-T ^  
} AF6d#Klog  
dNOX&$/=  
A Z4|&iT  
public String getSSiteURL() BO?mQu~  
{ - P\S>G.  
return sSiteURL; x1.3W j  
} hq5NQi` %  
' 9IP;  
zY]Bu-S3  
public void setSSiteURL(String value) 0|.7Kz^  
{ C<r(-qO{5  
sSiteURL = value; B*- ToXQQr  
} ,AdusM  
]jHgo](%  
,:v.L}+Z  
public String getSFilePath() &?KPu?9  
{ 4C l, Iw/;  
return sFilePath; o}WB(WsG  
} I(z>)S'7r  
aSn0o_4bD  
"}S9`-Wd|  
public void setSFilePath(String value) [54@irH  
{ IW5*9)N?  
sFilePath = value; A6{t%k~F  
} B`g<Ge~  
Q mb[ e>  
Rf)'HT  
public String getSFileName() .'l.7t  
{ di-O*ug  
return sFileName; Aivu%}_|  
} _ff=B  
@m+pr\h(  
GCcwEl!K^  
public void setSFileName(String value) e#l*/G*,  
{ g0^~J2sDd  
sFileName = value; >Sc$R0  
} mA&RN"+V  
F3k C"H  
(Wm/$P;  
public int getNSplitter() d%}crM-KTL  
{ r4;5b s6wm  
return nSplitter; ^m6k@VM  
} 9F2w.(m  
c*y$bf<  
LVPt*S=/  
public void setNSplitter(int nCount) ke3HK9P;  
{ - XE79 fQ  
nSplitter = nCount; Fy}MXe"f  
} xT_fr,P  
} .yctE:n  
^/`#9]<%  
PphR4 sIM  
/* Eg@R[ ^T  
**Utility.java _Vdb?  
*/ @D.R0uM  
package NetFox; ?RgU6/2  
pr0@sri@  
c[wQJc  
public class Utility { OoAr%  
JVJ1Ay/be  
j33P~H~  
public Utility() *=-__|t  
{ &[?u1qQ%o  
7h9fQ&y  
v$gMLu=  
} c8k6(#\  
&+E'1h10  
//线程睡眠 K#9(|2 J%  
public static void sleep(int nSecond) xG*lV|<7>  
{ ~pd1 )  
try{ %\(y8QV  
Thread.sleep(nSecond); uPv;y!Lsa@  
} )8 "EI-/.  
catch(Exception e) 68&6J's;  
{ Pe+ 8~0o=R  
e.printStackTrace (); :$SRG^7md  
} ; McIxvj  
} r 85Xa'hh  
,? 0-=o  
//日志 BNL8hK`D  
public static void log(String sMsg) yNhscAMNn  
{ 877EKvsiC  
System.err.println(sMsg); } #\;np  
} PBxK>a  
VgFF+Eg  
Se^/VVm  
public static void log(int sMsg) GvZac  
{ RvyBg:Aj5  
System.err.println(sMsg); /XWPN(JC?  
} [#hl}q(P#  
} 4pfix1F g  
`mq4WXO\  
_e:5XQ  
/* 0p:ClM 2O  
**TestMethod.java e6{[o@aM{  
*/ \J,- <wF  
package NetFox; xY\*L:TwW  
h9Tf@]W   
Y2=Brtc[@  
public class TestMethod { Oi kU$~|  
0_,3/EWa  
X YNUss  
public TestMethod() n3l"L|W^(<  
{ ///xx/weblogic60b2_win.exe 9Th32}H  
try{ 6yu*a_  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &{%S0\K Y  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #czyr@  
SiteFileFetch fileFetch = new SiteFileFetch(bean); D<_,>{$gW  
fileFetch.start(); }QWTPRn  
} A1k&` |k   
catch(Exception e){e.printStackTrace ();} PNxVW  
@Q$ /eL  
9?g]qy,1)  
} r7Q:l ?F2  
-_{C+Y_  
l $p_])x  
public static void main(String[] args) |oBdryi  
{ U>L=.\\|  
new TestMethod(); 48~m=mI  
} ]df9'\  
} 9aF..  
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