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http断点续传简单实现(java)

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/* ^T&@(|o  
**SiteFileFetch.java b;k3B7<  
*/ OPe3p {]  
package NetFox; )oAxt70  
import java.io.*; :)=>,XwL8  
import java.net.*; R;l;;dC=  
l\t\DX"s_  
'^10sf`"  
public class SiteFileFetch extends Thread { YDxEWK<  
1r?hRJ:'  
0+dc  
SiteInfoBean siteInfoBean = null; //文件信息Bean J<;@RK,c_  
long[] nStartPos; //开始位置 wY'w'%A?  
long[] nEndPos; //结束位置 ?_V&~?r   
FileSplitterFetch[] fileSplitterFetch; //子线程对象 1XXuFa&  
long nFileLength; //文件长度 uw>O|&!  
boolean bFirst = true; //是否第一次取文件 [Zxv&$SQ  
boolean bStop = false; //停止标志 'L$}!H1y  
File tmpFile; //文件下载的临时信息 c0aXOG^  
DataOutputStream output; //输出到文件的输出流 oqUF_kh  
;U)xZ _Ew~  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 3Z%~WE;I  
public SiteFileFetch(SiteInfoBean bean) throws IOException W{W8\  
{ 1LZ[i89&%  
siteInfoBean = bean; ~;S  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); DV{0|E  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); }huFv*<@'  
if(tmpFile.exists ()) +, |aIF  
{ K{ED mC  
bFirst = false; Swr 8  
read_nPos(); V]Z!x.x"=y  
} ``:+*4e9  
else kWMz;{I5*w  
{ l' mdj!{&  
nStartPos = new long[bean.getNSplitter()]; `p'682xI  
nEndPos = new long[bean.getNSplitter()]; +S6(Fvp  
} "zZ Z h  
bGtS! 'I  
X 7R&>Pf  
*YO^+]nmY  
} sD ,=_q@  
-\[H>)z]RB  
Kg6[  
public void run() e%_J O7  
{ f1w_Cl  
//获得文件长度 f>hA+  
//分割文件 PK).)5sW  
//实例FileSplitterFetch d+o.J",E  
//启动FileSplitterFetch线程 G0~6A@>  
//等待子线程返回 /N9ct4 {^  
try{ [JVEKc ym  
if(bFirst) !*e1F9k  
{ c4V%>A  
nFileLength = getFileSize(); iz%wozf  
if(nFileLength == -1) cNl NJ  
{ L+.&e4f'oj  
System.err.println("File Length is not known!"); E< Y!BT[X  
} q>rDxmP<  
else if(nFileLength == -2) 6m%#cP (6K  
{ ? FlQ\q  
System.err.println("File is not access!"); |}><)}  
} V jLv{f<p  
else !rsGCw!Pg  
{ MAQ(PIc>T  
for(int i=0;i<nStartPos.length;i++) %WF]mF T_  
{ e);`hNLih  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); aY-7K._</  
} 6o d^+>U  
for(int i=0;i<nEndPos.length-1;i++) PC!g?6J  
{ ^D8~s;?  
nEndPos = nStartPos[i+1]; aqEmF  
} {/}%[cY =  
nEndPos[nEndPos.length-1] = nFileLength; ey@ccc*sZ9  
} ]{| wU.  
} |/;;uK,y  
p1N3AhXY  
bRD-[)  
//启动子线程 )uu(I5St  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +L|x^ B3  
for(int i=0;i<nStartPos.length;i++) QpD- %gN  
{ 3O*^[$vM  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &u2H^ j  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x n=#4:f  
nStartPos,nEndPos,i); %uw7sGz\  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &WNIL13DK  
fileSplitterFetch.start(); UvR.?js(O  
} R-YNg  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A<_{7F9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ON9L+"vqv0  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !oa/\p  
nEndPos = " + nFileLength); Rt>mAU$}  
// fileSplitterFetch[nPos.length-1].start(); goe %'k,  
.*edaDi  
FsLd&$?T&  
//等待子线程结束 GL%)s?   
//int count = 0; h S)lQl:^  
//是否结束while循环 2]]}Xvx4#  
boolean breakWhile = false; h~lps?.#b  
ot0g@q[3  
5PsjGvm.%  
while(!bStop) Ya4yW9*  
{ #mYe@[p@  
write_nPos(); UD=[::##  
Utility.sleep(500); qP0UcG  
breakWhile = true; 22'Ra[  
D-FT3Culw  
{53|X=D64  
for(int i=0;i<nStartPos.length;i++) `S+n,,l  
{ iJH?Z,Tjf  
if(!fileSplitterFetch.bDownOver) g/frg(KF  
{ ;nrkC\SYh:  
breakWhile = false; t$ 97[ay  
break; *q"1I9zvT  
} G.r .Z0  
} gO{$p q}  
if(breakWhile) cJf&R^[T  
break; )t((x  
l9e=dV:pH  
9k \M<jA  
//count++; *cZ7?  
//if(count>4) M@JW/~p'  
// siteStop(); nDcH;_<;9a  
} h$mGaw vZ~  
PhAD: A  
\l%##7DRp]  
System.err.println("文件下载结束!"); a6@k*9D>  
} jvxCCYXR  
catch(Exception e){e.printStackTrace ();} &kcmkRRG  
} R xS{  
W[sQ_Z1C  
z%BX^b$Hj  
//获得文件长度 E@EP9X >  
public long getFileSize() &c}2[=  
{ PjofW%7F  
int nFileLength = -1; |qVM`,%L  
try{ =KAN|5yn  
URL url = new URL(siteInfoBean.getSSiteURL()); ?D|kCw69SE  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); * =*\w\ te  
httpConnection.setRequestProperty("User-Agent","NetFox"); L1WvX6  
*pDS%,$xe  
p( )LQT!  
int responseCode=httpConnection.getResponseCode(); !L( )3=  
if(responseCode>=400) k{O bm g  
{ 1_TniR3z1  
processErrorCode(responseCode); hYh~%^0dt  
return -2; //-2 represent access is error D<:zw/IRE  
} X,c`,B03  
)3R5cq  
c>3j $D+  
String sHeader; *2fJdY  
(&u'S+  
C\Z5%2<Z  
for(int i=1;;i++)  [aG   
{ 4T$DQK@e  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &bGf{P*Da  
//Utility.log(in.readLine()); d,o*{sM5d  
sHeader=httpConnection.getHeaderFieldKey(i); 7kITssVHI  
if(sHeader!=null) ~T/tk?:8Vi  
{ f$5\ b[O  
if(sHeader.equals("Content-Length")) _8ks`O#}  
{ nN^lY=3  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); unNN&m#@  
break; =**Q\ Sl  
} %%#bTyF  
} <Ql2+ev6  
else 24 .'+3  
break; GvvKM=1  
} 9-vQn/O^D  
} =Ot_P7'5gv  
catch(IOException e){e.printStackTrace ();} Gx4{ 9  
catch(Exception e){e.printStackTrace ();} )TyP{X>  
]omBq<ox'Y  
'vYt_T  
Utility.log(nFileLength); !]5V{3  
17`-eDd  
?*[35XUd  
return nFileLength; g7lPQ_A*  
} x8x-b>|$&<  
1|AY&u%fiP  
fz?woVn  
//保存下载信息(文件指针位置) :`lP+y?a1  
private void write_nPos() }: u-l3e  
{ Sx (E'?]  
try{ |qwx3 hQ?  
output = new DataOutputStream(new FileOutputStream(tmpFile)); f@$kK?c?  
output.writeInt(nStartPos.length); d'H gek{T  
for(int i=0;i<nStartPos.length;i++) |DPq~l(d  
{ ms\\R@R  
// output.writeLong(nPos); 6!USSipn  
output.writeLong(fileSplitterFetch.nStartPos); gzy|K%K  
output.writeLong(fileSplitterFetch.nEndPos); ]vPdj"7  
} $pt~?ZZ3-  
output.close(); mB6%. "  
} GctV  
catch(IOException e){e.printStackTrace ();} OEX\]!3_Fm  
catch(Exception e){e.printStackTrace ();} LPZ\T} <l  
} =6f)sZpPh  
6__HqBQ  
^t*Ba>A  
//读取保存的下载信息(文件指针位置) 1*'gaa&y  
private void read_nPos() 6.$z!~8  
{ (i?9/8I  
try{ 9Zmq7a E  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w~jm0jK]  
int nCount = input.readInt(); [@B!N+P5;  
nStartPos = new long[nCount]; c.5u \ I9"  
nEndPos = new long[nCount]; \rO!lvX  
for(int i=0;i<nStartPos.length;i++) +\u\BJ!LAJ  
{ f! )yE`4-  
nStartPos = input.readLong(); 'i:lV'  
nEndPos = input.readLong(); 86!$<!I  
} $ER9u2  
input.close(); F-M)6&T  
} 'H4?V  
catch(IOException e){e.printStackTrace ();} B2KBJ4rI[1  
catch(Exception e){e.printStackTrace ();} FFe{=H,=  
} J\p-5[E  
B/^o$i  
H0yM`7[y  
private void processErrorCode(int nErrorCode) e 'F:LMX  
{ sY?wQ:  
System.err.println("Error Code : " + nErrorCode); rx@i .+  
} !, rF(pz  
D~|q^Ms,%  
fZLAZMrM  
//停止文件下载 8<32(D{  
public void siteStop() k7L4~W  
{ R~|(]#com  
bStop = true; ${}9/(x/^  
for(int i=0;i<nStartPos.length;i++) 2- (}=N  
fileSplitterFetch.splitterStop();  B@*!>R  
:#{0yno)H  
Iz;^D!  
} Q`Q"p  
} `*`ZgTV  
//负责部分文件的抓取 #l.s> B4  
**FileSplitterFetch.java OECVExb@eH  
*/ yu > ;m.e_  
package NetFox; J!dv"Ww"  
rusYNb1J  
Fu\#:+5\  
import java.io.*; j~>J?w9<O  
import java.net.*; R6:m@  
ipt]qJFd  
8Bh micU  
public class FileSplitterFetch extends Thread { hd[t&?{=  
}odjaM}5Nc  
TDWD8??e  
String sURL; //File URL s8qpK; O  
long nStartPos; //File Snippet Start Position Fpwhyls  
long nEndPos; //File Snippet End Position rY1jC\  
int nThreadID; //Thread's ID Ke]'RfO\  
boolean bDownOver = false; //Downing is over ,^<39ng  
boolean bStop = false; //Stop identical ^gNbcWc7CU  
FileAccessI fileAccessI = null; //File Access interface ~?)y'?  
AMO{ee7Po  
L|1~'Fz#w  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tL1\q Qg  
{ ac966<#  
this.sURL = sURL; _\= /~>Xl  
this.nStartPos = nStart; 4cJ/XgX  
this.nEndPos = nEnd; *,*XOd:3TL  
nThreadID = id; gw%L M7yQR  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :S!!J*0  
} HCe/!2Y/%  
>Rb jdM5K4  
0dI7{o;<|  
public void run() ,OP\^  
{ 4!-R&<TLve  
while(nStartPos < nEndPos && !bStop) Z@$'fX?~9  
{ `Hv"^o  
i }Zz[b  
r(_Fr#Qn  
try{ * kUb[  
URL url = new URL(sURL); 5lM 3In@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d-W*`:Q  
httpConnection.setRequestProperty("User-Agent","NetFox"); TIaiJvo  
String sProperty = "bytes="+nStartPos+"-"; n!lE|if  
httpConnection.setRequestProperty("RANGE",sProperty); [9Tnp]q  
Utility.log(sProperty); "T<7j.P?  
5LU7}v~/  
sqjDh  
InputStream input = httpConnection.getInputStream(); huR ^l  
//logResponseHead(httpConnection); N+H[Y4c?F&  
*A")A.R  
9;`hJ!r  
byte[] b = new byte[1024]; XaoVv2=G~  
int nRead; 8,VEuBZ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =)N6 R  
{ m6 Y0,9  
nStartPos += fileAccessI.write(b,0,nRead); A2\3.3  
//if(nThreadID == 1) /'_Yct=  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v:>sS_^  
} [biz[ fm  
+bb-uoZf  
wqap~X  
Utility.log("Thread " + nThreadID + " is over!"); ; vWJOvM2  
bDownOver = true; f}ch1u>  
//nPos = fileAccessI.write (b,0,nRead); fjuPGg~  
} *#@{&Q(Qh  
catch(Exception e){e.printStackTrace ();} ,:V[H8 ?  
} 1:./f|m  
} I?%#`Rvu  
iU=:YPE+ .  
u09D`QPP]  
//打印回应的头信息 +>c%I&h}`  
public void logResponseHead(HttpURLConnection con) z U *Mk  
{ AXnKhYlu  
for(int i=1;;i++) (OavgJ+Y  
{ D$w?  
String header=con.getHeaderFieldKey(i); Bi"cWO  
if(header!=null) e ^`La*n  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8vfC  
Utility.log(header+" : "+con.getHeaderField(header)); <$#^)]Ts  
else at2)%V)  
break; ?nE9@G5Gc  
} _(8N*q*w  
} RmO kb~  
uBC#4cX`D*  
1Vz3N/AP%?  
public void splitterStop() {?A/1q4rr  
{ 8)83j6VF  
bStop = true; /;u=#qu(E-  
} ') 2LP;(  
q%)."10}]  
ltkA7dUbu  
} 1$:O9 {F  
m Q<Vwx0  
c{x:'@%/s'  
/* ld5+/"$  
**FileAccess.java zY-?Bv_D  
*//文件访问(定位,写)  qzSm]l?z  
package NetFox; bhfKhXh8  
import java.io.*; \`-xxhb?e  
(&_^1  
[g=4'4EZc  
public class FileAccessI implements Serializable{ ?f!&M  
e. E$Ej]w  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zcio\P=^|B  
RandomAccessFile oSavedFile; ,.;{J|4P  
long nPos; O >@Q>Z8W?  
^.*zBrFx  
8hSw4S "$  
public FileAccessI() throws IOException 7x*C` Et<x  
{ ws U@hqS  
this("",0); n S Vr,wU  
} 4ZYywDwn  
64^3ve3/a=  
i@%a!].I  
public FileAccessI(String sName,long nPos) throws IOException ogV v 8Xb  
{ |F qujZz  
oSavedFile = new RandomAccessFile(sName,"rw"); ?d k)2  
this.nPos = nPos; |ss4pN0X  
oSavedFile.seek(nPos); a,n#E!zT?w  
} 4]xD-sc  
lcfs 1].  
uE.. 1N&*  
public synchronized int write(byte[] b,int nStart,int nLen) NZ+TTMv  
{ "od 2i\  
int n = -1; %"|W qxv  
try{ sn'E}.uhXH  
oSavedFile.write(b,nStart,nLen); }"/>,  
n = nLen; 0^F!-b^z  
} e Dpt1  
catch(IOException e) SI=7$8T5=5  
{ (SA^> r  
e.printStackTrace (); ],'"iVh  
} dMI G2log  
~Ds3 -#mMy  
{qs>yQ6a:-  
return n; X3~@U7DU  
} Oz<#s{Z  
"DX 2Mu=  
/38XaKc{6  
} )vY)Mg  
F8\JL %  
8RS@YO  
/* @R`Ao9n9V  
**SiteInfoBean.java tK 6=F63e  
*/ jFI`CA6P  
package NetFox; MaF4lFmS  
CWb*bw0  
/HdjPxH  
public class SiteInfoBean { ^#4<~zU  
on1B~?*D  
*{O[}  
private String sSiteURL; //Site's URL tNYuuC%N  
private String sFilePath; //Saved File's Path B!4~A{  
private String sFileName; //Saved File's Name L}K8cB  
private int nSplitter; //Count of Splited Downloading File ^bLFY9hSC  
o76{;Bl\O  
iUZV-jl2/  
public SiteInfoBean() =i},$"Bf*%  
{//nSplitter的缺省值为5 | _nBiHjNn  
//default value of nSplitter is 5 VWk{?*Dp  
this("","","",5); f`[E^ zj  
} iAt&927  
p ^)3p5w  
q-/t?m0  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L08lkq,  
{ %Vk77(  
sSiteURL= sURL; WM ]eb, 8q  
sFilePath = sPath; 8KsPAK_  
sFileName = sName; NC sem  
this.nSplitter = nSpiltter; <driD'=F  
Tz&h[+6`  
v]}\Ns/  
} YhP+{Y8t  
VDiW9]  
p@oz[017/J  
public String getSSiteURL() Ue!yK  
{ f*Os~@K  
return sSiteURL; 1R7tnR@[u  
} xrv0%  
T`GiM%R;g  
.X:,]of  
public void setSSiteURL(String value) hUEA)c  
{ yA';~V\V{>  
sSiteURL = value; wR"17z7[]  
} |<MSV KW  
B#3Q4c$  
HumL(S'm  
public String getSFilePath() 7"OJ,Mx%  
{ xl@~K^c]  
return sFilePath; bL5u;iy)  
} ?. Ip(g  
*JZlG%z  
vx}BT H  
public void setSFilePath(String value) >Sb3]$$  
{ s@ 6Jz\<E  
sFilePath = value; "/%o'Fq  
} 2WE01D9O  
1*.*\4xo  
o/& IT(v  
public String getSFileName() L-%'jR  
{ m^w{:\p  
return sFileName; 1\g r ;b  
} `O`MW} c  
hoLA*v2<  
t/l<X]o  
public void setSFileName(String value) P(a}OlG  
{ %D~Mij  
sFileName = value; R \]C;@J<  
} -lR7 @S  
{BgJ=0g?  
yJ ;Qe_up  
public int getNSplitter() $#(j2sL1  
{ o'8nQ Tao  
return nSplitter; ;s-@m<  
} tq51;L  
LjIkZ'HuF  
D0>Pc9  
public void setNSplitter(int nCount) #$F*.vQSs+  
{ 9TwKd0AT$&  
nSplitter = nCount; I1I-,~hO  
} <kWkc|z BY  
} *]nk{jo2  
`>OKV;~{z  
6Cfsh<]b  
/* %/qwqo`Q  
**Utility.java z[y  
*/ v8n^~=SH  
package NetFox; Xg;;< /Z  
mA@!t>=oMq  
kI2+&  
public class Utility { ae](=OQ  
/Z[HU{4  
c e; zn\  
public Utility() lQy-&d|=#^  
{ |kTq &^$  
WBb*2  
^;tB,7:*V  
} f .$*9Fkw  
|sEuhP\A3  
//线程睡眠 Nr).*]g@~  
public static void sleep(int nSecond) )uMv]  
{ D4uAwmc  
try{ d24_,o\_  
Thread.sleep(nSecond); 7 p1B"%  
} 9A/bA|$  
catch(Exception e) >0uj\5h)I]  
{ A;dD'Kgl  
e.printStackTrace (); Et0)6^-v  
} *adznd  
} ) .KMZ]  
`zB bB^\`W  
//日志 /)kx`G_  
public static void log(String sMsg) PB!XApTb  
{ hljKBx ~  
System.err.println(sMsg); _O ;4>  
} CGkx_E]  
B^/k`h6J  
o\; hF3   
public static void log(int sMsg) 6As%<g=  
{ Dwr 9}Z-]  
System.err.println(sMsg); Bf6i{`!G  
} E+LQyvF[  
} "_&c[VptWi  
xGOVMo +  
L ./c#b!{  
/* g-1j#V`5  
**TestMethod.java X$6QQnyR  
*/ Y=g]\%-PB  
package NetFox; 7upWM~H^  
f re5{=@  
pLys%1hg  
public class TestMethod { /J&ks>St  
*N }$~N  
E31Yk D.A  
public TestMethod() 7#NHPn  
{ ///xx/weblogic60b2_win.exe O .-n&U9  
try{ $EEn]y  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M&<qGV$A  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _:WNk(  
SiteFileFetch fileFetch = new SiteFileFetch(bean); x+;y0`oL  
fileFetch.start(); =N8_S$nx(  
} 29VX-45  
catch(Exception e){e.printStackTrace ();}  m l@% H  
V|[NL4  
+|7N89l  
} DEt!/a{X  
z[myf] @  
x<' $  
public static void main(String[] args) ;R Jv7@  
{ k7;i^$@c  
new TestMethod(); /wl]kGF  
} U_ j[<.aN)  
} A*A/30o|R  
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