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http断点续传简单实现(java)

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/* F?4'>ZW  
**SiteFileFetch.java Ss/="jC  
*/ @WE$%dr  
package NetFox; <p8y'KAlc  
import java.io.*; mT$tAwzTC{  
import java.net.*; "N"k8,LH  
nUu|}11(  
, |B\[0p  
public class SiteFileFetch extends Thread { &BR?;LD  
?2/M W27w  
Bd[}A9O[  
SiteInfoBean siteInfoBean = null; //文件信息Bean $f\-.7OD  
long[] nStartPos; //开始位置 c>k6i?u:X7  
long[] nEndPos; //结束位置 L(rjjkH  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 spDRQ_qq  
long nFileLength; //文件长度 !ry+ r!"  
boolean bFirst = true; //是否第一次取文件 PQ|x?98  
boolean bStop = false; //停止标志 |"*:ZSj  
File tmpFile; //文件下载的临时信息 No+zw%l0E  
DataOutputStream output; //输出到文件的输出流 JFkjpBS  
aDEP_b;  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类)  'Z}$V*  
public SiteFileFetch(SiteInfoBean bean) throws IOException t;6/bT-  
{ >b${rgCvQ  
siteInfoBean = bean; cK/odOi  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); >QPS0Vx[  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); \'b- ;exH  
if(tmpFile.exists ()) D(GHkS*0q  
{ >FhBl\oIi  
bFirst = false; K6Ua~N^  
read_nPos(); >,1LBM|0u  
} Y5 pNKL  
else T!E LH!  
{ (]dZ+"O{  
nStartPos = new long[bean.getNSplitter()]; rrq-so1u}  
nEndPos = new long[bean.getNSplitter()]; 'D{abm0  
} k}gs;|_  
7 4UE-H)  
XcneH jpR  
);LwWKa  
} PUArKBYM-  
zvg&o)/[  
s o s&  
public void run() 34+}u,=  
{ Fb-TCq1y#  
//获得文件长度 9|DC<Zn&B#  
//分割文件 ;c}];ZU3G  
//实例FileSplitterFetch +r"$?bw '  
//启动FileSplitterFetch线程 W5{e.eI}|  
//等待子线程返回 n&JP/P3Y  
try{ Ss}0.5Bq  
if(bFirst) b@Cvs4  
{ ^5F/=TtE G  
nFileLength = getFileSize(); i>}z$'X  
if(nFileLength == -1) )I9(WVx!]  
{ sP!qv"u  
System.err.println("File Length is not known!"); mer{Jy s  
} Rl8-a8j$f.  
else if(nFileLength == -2) W,+91rup  
{ Q0q$ZK6C  
System.err.println("File is not access!"); VVOt%d  
} W=:+f)D  
else N<WFe5  
{ tDVdl^#  
for(int i=0;i<nStartPos.length;i++) Uk4">]oct  
{ 8&bj7w,K  
nStartPos = (long)(i*(nFileLength/nStartPos.length));  X'<xw  
} ;C%EF  
for(int i=0;i<nEndPos.length-1;i++) 1C{n\_hR  
{ i&KODhMpP  
nEndPos = nStartPos[i+1]; fZC,%p  
} e^TF.D?RS  
nEndPos[nEndPos.length-1] = nFileLength; }vIm C [  
} 4vphLAm  
} Y'9deX+  
t=#)3C`Q}  
I 3PnyNZ  
//启动子线程 PHkvt!uH  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Cz%ih#^b  
for(int i=0;i<nStartPos.length;i++) 71InYIed  
{ $G[##j2  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), he #iWD'  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C/=ZNl9"fn  
nStartPos,nEndPos,i); L`v,:#Y   
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q)X&S*-<o~  
fileSplitterFetch.start(); w93,N+es6  
} *yx:nwmo  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FqfeH_-U  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Sz&`=x#  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cA kw5}P   
nEndPos = " + nFileLength); 4(]k=c1<  
// fileSplitterFetch[nPos.length-1].start(); @U5o;X!qU  
&[uGfm+@  
=v-D}eJQ=  
//等待子线程结束 q6dq@   
//int count = 0; h?sh#j6  
//是否结束while循环 c-F&4V  
boolean breakWhile = false; 4m:E:zVn  
vbp)/I-h  
)C[8#Q-:  
while(!bStop) +]X^bB[  
{ yI)2:Ca*  
write_nPos(); U<x3=P  
Utility.sleep(500); RD^o&VXO  
breakWhile = true; 2#!D"F  
9^n ]qg^  
pFh2@O  
for(int i=0;i<nStartPos.length;i++) ~ p.23G]x  
{ R\^tr  
if(!fileSplitterFetch.bDownOver) LCt m@oN  
{ Ue7~rPdlR  
breakWhile = false; '4iu0ie>D  
break; c<=1,TB"-_  
} 'E9jv4E$n  
} i \~4W$4I  
if(breakWhile) !VW#hc \A5  
break; ?`xId;}J#7  
R0>L[1o  
'@FKgy;B)-  
//count++; BshS@"8r  
//if(count>4) XcXd7e  
// siteStop(); rlq8J/0/+  
} .dV!du  
O;~1M3Ii  
*7ox_ R@  
System.err.println("文件下载结束!"); tF 4"28"h  
} N.]8qzW  
catch(Exception e){e.printStackTrace ();} =B\ ?(  
} ZHT.+X:_  
xAI<<[-  
<}evOw2  
//获得文件长度 /T?['#:r-)  
public long getFileSize() hikun 2  
{ ji "*=i  
int nFileLength = -1; lPH]fWt<  
try{ *m2:iChY  
URL url = new URL(siteInfoBean.getSSiteURL()); {r"HR%*u  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `k+k&t  
httpConnection.setRequestProperty("User-Agent","NetFox"); y(HR1v Q;Z  
e>[QF+e)y  
%}@^[E)  
int responseCode=httpConnection.getResponseCode(); &\A$Rj)  
if(responseCode>=400) F[lHG,g-  
{ ?w.Yx$Z"  
processErrorCode(responseCode); : v]< h  
return -2; //-2 represent access is error 6i%)'dl  
} _$\T;m>'A  
?@ O[$9y  
z;-2xD0&U[  
String sHeader; P _9O8"W  
KF.?b]  
$ysC)5q.  
for(int i=1;;i++) iVD9MHT4  
{ ;fuy}q8@7  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !e?\> '  
//Utility.log(in.readLine()); E @7! :  
sHeader=httpConnection.getHeaderFieldKey(i); u{si  
if(sHeader!=null) &{$\]sv  
{ {d) +a$qj  
if(sHeader.equals("Content-Length"))  H='`#l1  
{ B;EdLs}  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +f+\uObi:  
break; 1:-$mt_*  
} +m"iJW0  
} QDU^yVa_  
else 7%X$6N-X  
break;  #/n\C  
} |XQ!xFB  
} '1d-N[  
catch(IOException e){e.printStackTrace ();} P/27+5(|  
catch(Exception e){e.printStackTrace ();} !=a8^CV  
Es?~Dd  
$]O\Ryf6  
Utility.log(nFileLength); :g Ze>  
&.d~ M1Mz  
aFLm,  
return nFileLength; %;gD_H4mm  
} R\iU)QP  
U!('`TYe  
2rA`y8g(L  
//保存下载信息(文件指针位置) h4V.$e<T&  
private void write_nPos() c| E  
{ k1X<jC]P  
try{ ) +{'p0  
output = new DataOutputStream(new FileOutputStream(tmpFile)); C; ! )<(Vw  
output.writeInt(nStartPos.length); |XeuqZa  
for(int i=0;i<nStartPos.length;i++) zdr?1=  
{ 7.]ZD`"Bb  
// output.writeLong(nPos); gbF.Q7?$u  
output.writeLong(fileSplitterFetch.nStartPos); JTVCaL3Z  
output.writeLong(fileSplitterFetch.nEndPos); tL D.e  
} *F=w MWa  
output.close(); 2Ddrxc>48  
} hF6EOCY6D  
catch(IOException e){e.printStackTrace ();} )4j#gHN\  
catch(Exception e){e.printStackTrace ();} &0M^UvO  
} 98x(2fCvF(  
WFtxEIrl3j  
GX\/2P7CZ  
//读取保存的下载信息(文件指针位置) " 4s,a  
private void read_nPos() (d_{+O"  
{ _,5(HETE2  
try{ U:ZklDW  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #\w~(Nm-  
int nCount = input.readInt(); Rf7py)  
nStartPos = new long[nCount]; ^}9Aq $R  
nEndPos = new long[nCount]; [~ fJ/  
for(int i=0;i<nStartPos.length;i++) Ucv-}oa-?  
{ HZR~r:_ i  
nStartPos = input.readLong(); NX$$4<A1  
nEndPos = input.readLong(); \s [Uq  
}  F`f#gpQ  
input.close(); R7+k=DI  
} UAa2oY&  
catch(IOException e){e.printStackTrace ();} 2uz<n}IV  
catch(Exception e){e.printStackTrace ();} yt$V<8a  
} UA}k"uM  
d!!5'/tmS  
 u"tv6Qp  
private void processErrorCode(int nErrorCode) A2]N :=  
{ "#(]{MY  
System.err.println("Error Code : " + nErrorCode); IS"UBJ6p  
} Yk[yG;W  
9;kWuP>k4u  
)'92{-A0  
//停止文件下载 (eHvp  
public void siteStop() <Cm:4)~  
{ )t0t*xu#  
bStop = true; IeE+h-3p  
for(int i=0;i<nStartPos.length;i++) eo"6 \3z  
fileSplitterFetch.splitterStop(); l1a=r:WhH  
~,.Agx  
TR| G4l?  
} % `\8z  
} J7$5<  
//负责部分文件的抓取 RytQNwv3  
**FileSplitterFetch.java qd"*Td  
*/ P5kkaLzG  
package NetFox; db4Ol=  
L Ktr>u  
pz~AsF  
import java.io.*; UEt #;e  
import java.net.*; g;Bq#/w  
#N wlKZ-  
9w(QM-u  
public class FileSplitterFetch extends Thread { Rax}r  
3%>"|Ye}A  
^<7)w2ns  
String sURL; //File URL {6*h';~  
long nStartPos; //File Snippet Start Position uG~%/7Qt{  
long nEndPos; //File Snippet End Position L3'o2@$  
int nThreadID; //Thread's ID 5Y JLR;  
boolean bDownOver = false; //Downing is over Lr_+) l  
boolean bStop = false; //Stop identical @zW'!Ol  
FileAccessI fileAccessI = null; //File Access interface d2Bn`VI  
1P@&xcvS\  
J8~3LE )G  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WADNr8.  
{ g.Z>9(>;Y  
this.sURL = sURL; eLM_?9AZ!R  
this.nStartPos = nStart; 0(h *< g:  
this.nEndPos = nEnd; E XEae ?  
nThreadID = id; Xb5n;=)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h{VCx#!]  
} bo`w( h_  
Fn yA;,*  
#P<v[O/rA  
public void run() JEGcZeq)  
{ \ @3i=!  
while(nStartPos < nEndPos && !bStop) +kmPQdO;*/  
{ x/R|i%u-s  
+(QGlRd  
-%NT)o  
try{ ma?$@ ]`k  
URL url = new URL(sURL); r. =_=V/t  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }2-{4JIq}  
httpConnection.setRequestProperty("User-Agent","NetFox"); 2>_6b>9]  
String sProperty = "bytes="+nStartPos+"-"; 7JQ5OC3  
httpConnection.setRequestProperty("RANGE",sProperty); UXnd~DA  
Utility.log(sProperty); z{7&=$  
Y6,< j|  
p (:\)HP)R  
InputStream input = httpConnection.getInputStream(); 8(\Az5%  
//logResponseHead(httpConnection); [89#8|+  
(Rve<n6{A  
; P&K a  
byte[] b = new byte[1024]; W:ih#YW_F  
int nRead; %DbL|;z1  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y!h$Z6.  
{ g < M\zD  
nStartPos += fileAccessI.write(b,0,nRead); l!EfvqWX  
//if(nThreadID == 1) ,0[bzk  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S9t_2%e  
} 1BmevE a)  
cL7je  
p9y "0A|  
Utility.log("Thread " + nThreadID + " is over!"); {|O8)bW'  
bDownOver = true; YO|Kc {j2e  
//nPos = fileAccessI.write (b,0,nRead); % Lhpj[C  
} dc|"34;^"  
catch(Exception e){e.printStackTrace ();} T4F}MVK  
} k^:$ETW2 D  
} j]6 Z*AxQ  
&Ru|L.G`  
4t|ril``]  
//打印回应的头信息 Eo!1 WRruF  
public void logResponseHead(HttpURLConnection con) e%afK@c  
{ tK`sVsm>  
for(int i=1;;i++) .R#p<"$I  
{ j *Ta?'*  
String header=con.getHeaderFieldKey(i); lc,{0$ 1<  
if(header!=null) ={o>g '  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s =! y%  
Utility.log(header+" : "+con.getHeaderField(header)); 'p80X^g  
else 7%c9 nY  
break; \f}S Hh  
} &HNJ '  
} wWKC.N  
><mZOTn e;  
TxoMCN?7c  
public void splitterStop() be|k"s|6)  
{ xa[<k >r3  
bStop = true; $6L gaz  
} &.y:QVR,!  
BuCU_/H  
0m(/hK  
} rUvqAfE&+  
Xp[[ xV|  
eu@-v"=w  
/* O5CIK}A  
**FileAccess.java L=O,OS+  
*//文件访问(定位,写) Cg?D<l4  
package NetFox; #'^!@+)  
import java.io.*; tV<}!~0,*  
tO~DA>R  
I,(m\NalK  
public class FileAccessI implements Serializable{ 7hZCh,O  
@NWjYHM[`  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2`Ub;Nn29  
RandomAccessFile oSavedFile; 4_Tx FulX.  
long nPos; WO?EzQ ?  
s#/JMvQ#  
s^TF+d?B  
public FileAccessI() throws IOException \rY|l  
{ iNUisl  
this("",0); q(M[ij  
} CkE@ Ll3Z  
9$c0<~B\  
P%z\^\p"5  
public FileAccessI(String sName,long nPos) throws IOException T^B&GgW  
{ p+ SFeUp  
oSavedFile = new RandomAccessFile(sName,"rw"); }L^Yoq]  
this.nPos = nPos; IsxPm9P2<  
oSavedFile.seek(nPos); (cAv :EKpo  
} +Pd&YfU9  
_A|1_^[G(  
z6#N f,  
public synchronized int write(byte[] b,int nStart,int nLen) eS8tsI  
{ ,>A9OTSN\  
int n = -1; TviC1 {2  
try{ ]:(>r&'  
oSavedFile.write(b,nStart,nLen); :WIbjI=  
n = nLen; !MS z%QcO  
} =unMgX]$  
catch(IOException e) M7-piRnd4  
{ <"{Lv)4  
e.printStackTrace (); aR6?+`6<  
} O@{ JB  
BQ{Gp 2N  
S}gUz9ks  
return n; mf=,6fx28  
} =K I4  
RXh0hD  
k!H;(B"s-  
} /6B!& b2f  
@a#qq`b;  
VQ5T$,&  
/* v|t_kNX;v*  
**SiteInfoBean.java WCA`34(  
*/ /Mb?dVwA  
package NetFox; O6LZ<}oUR  
&&4av*\I  
zYO+;;*@  
public class SiteInfoBean { E]WammX c  
N3g[,BE  
fIN8::Cs[  
private String sSiteURL; //Site's URL XL c&7  
private String sFilePath; //Saved File's Path M>P-0IC  
private String sFileName; //Saved File's Name ;ZPAnd:pb  
private int nSplitter; //Count of Splited Downloading File .%_scNP  
$%ZEP> ]  
X&nkc/erx  
public SiteInfoBean() 5|f[evQj<S  
{//nSplitter的缺省值为5 O|m-Uz"+  
//default value of nSplitter is 5 3.U5Each-  
this("","","",5); zB/$*Hd  
} sJg-FVe2  
uy)iB'st&  
>DVjO9Kf  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9_V'P]@  
{ ..V6U"/  
sSiteURL= sURL; ]Cnj=\'  
sFilePath = sPath; #x$.  
sFileName = sName; o)F^0t  
this.nSplitter = nSpiltter; 8~AO~  
$J"}7+  
jo{[*]Oa  
} ~j}di^<{  
dy N`9  
P$S>=*`n U  
public String getSSiteURL() 6f,#O8]#5  
{ u:& gp  
return sSiteURL; Yf&x]<rkCp  
} ,+<NP}Yg#G  
pm$,B7Q`oO  
z #c)Q  
public void setSSiteURL(String value) 3ddH@Y|  
{ TzmoyY  
sSiteURL = value; = q9>~E{}  
} LL|$M;S  
mG@xehH  
b<};"H0a  
public String getSFilePath() e#JJd=  
{ W4Rs9NA}  
return sFilePath; 9Slx.9f  
} -'3~Y 2#  
Zm,<2BP>  
/ >c F  
public void setSFilePath(String value) 8X!^ 2B}J  
{ 'hfQ4EN  
sFilePath = value; ]f#ZU{A'mt  
} -8;U1^#  
<iVn!P  
fiqeXE?E  
public String getSFileName() S {gB~W  
{ ax0RtqtR&  
return sFileName; :pj#t$:!  
} \E1[ /  
7y.$'<  
NBZFIFO<  
public void setSFileName(String value) -:b0fKn  
{ H(9%SP@[c  
sFileName = value; GhpVi<FL  
} ' _Ij9{M  
ukb2[mb*u  
 +LeZjA[  
public int getNSplitter() @N,dA#  
{ ]+\;pb}bq  
return nSplitter; ~6L\9B )  
} z}&w7 O#   
:5IbOpVM  
PrqN5ND  
public void setNSplitter(int nCount) 4<g,L;pUU  
{ .<5 66g}VP  
nSplitter = nCount; BC0SSR@e  
} oV"#1lp*  
} l\< *9m<  
:"5'l>la  
|LA@guN  
/* D_er(  
**Utility.java rKg~H=4x2  
*/ .si!`?K%[  
package NetFox; 0J7)UqMf.  
,pL%,>R5  
,paD/  
public class Utility { L]I ;{Y  
r(-`b8ZE  
0m k-o  
public Utility() %K[_;8  
{ I:M]#aFD  
6qg_&woJ3  
w&<-pIa`  
}  Xr'Y[E [  
AX3iB1):K  
//线程睡眠 !\w@b`Iv8  
public static void sleep(int nSecond) I?c "\Fe  
{ kSj,Pl\NC  
try{ ?EQ]f34  
Thread.sleep(nSecond); E wDFUK  
}  V9\g?w  
catch(Exception e) Z9TmX A@  
{ 9NXf~-V-  
e.printStackTrace (); L:UJur%  
} j6<o,0P  
} [yj-4v%u`  
gI<e=|J6w  
//日志 -DD2   
public static void log(String sMsg) /NRdBN  
{ L-Qc[L  
System.err.println(sMsg); s/#L?[YH  
} j_L1KB*  
C3 >X1nU  
^y:!=nX^  
public static void log(int sMsg)  1t7vP;  
{ l]tda(  
System.err.println(sMsg); CqHCJ '  
} p2T<nP<Pt  
} 5n,?&+*L  
USBU?WDt  
t* eZe`|  
/* rC )pCC  
**TestMethod.java /4x3dwXW@  
*/ > Q[L, I  
package NetFox; $M%<i~VXe&  
W ~(4t:hp  
( -^-  
public class TestMethod { b {fZU?o  
1=Npq=d  
+pDZ,c,  
public TestMethod() K??(>0Qr}r  
{ ///xx/weblogic60b2_win.exe n:QFwwQ`Q;  
try{ kB~KC-&O  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cTlitf9  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o[<lTsw<  
SiteFileFetch fileFetch = new SiteFileFetch(bean); tx0`#x  
fileFetch.start(); 9?M>Y?4  
} ]M2<b:yo  
catch(Exception e){e.printStackTrace ();} }EFMJ,NQ  
q6E8^7RtS@  
7bcl^~lY  
} , c3gW2E  
^\|Hz\"*  
tR`'( *wh  
public static void main(String[] args) x@^Kd*fo  
{ OJX* :Q  
new TestMethod(); "h.-qQGU%  
} B,rpc\_  
} "p,TYjT?R  
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