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http断点续传简单实现(java)

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/* &Ci_wDJ  
**SiteFileFetch.java ?]}=4  
*/ D{+D.4\  
package NetFox; 1P BnGQYM  
import java.io.*; F=UW[zy/[  
import java.net.*; pC&i!la{o}  
09iD| $~  
[eDRghK  
public class SiteFileFetch extends Thread { dVJ9cJ9^  
Lk)TK/JM)  
+xr;X 9  
SiteInfoBean siteInfoBean = null; //文件信息Bean 1aUu:#c  
long[] nStartPos; //开始位置 #yCnM]cEn  
long[] nEndPos; //结束位置 a^&RV5o  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 LsK fCB}  
long nFileLength; //文件长度 |c2;`T#`o  
boolean bFirst = true; //是否第一次取文件 "nNT9 K|  
boolean bStop = false; //停止标志 "x3!F&  
File tmpFile; //文件下载的临时信息 ?J"Y4,{  
DataOutputStream output; //输出到文件的输出流 g(F2IpUm/  
1-G-p:|  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) "?J f#  
public SiteFileFetch(SiteInfoBean bean) throws IOException I%0J=V;o{  
{ You~ 6d6Om  
siteInfoBean = bean; L[:M[,?=`  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); .4=A:9  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); d%1 Vby  
if(tmpFile.exists ()) `_{,4oi  
{ gg Hl{cl)  
bFirst = false; !U1V('   
read_nPos(); J=#9eW  
} ^$8WV&5q>  
else tkHUX!Ow;  
{ 52*KRq o  
nStartPos = new long[bean.getNSplitter()]; r"lh\C|  
nEndPos = new long[bean.getNSplitter()]; Lo9 \[4FP  
} h*mKS -TC  
bWB&8&p  
49B6|!&I  
tkdyR1-  
} 3TKl  
EmV ZqW  
%bhFl,tL  
public void run() Z1DF)  
{ &Qv%~dvW  
//获得文件长度 9:Z|Z?>?  
//分割文件 a S+i`A:a  
//实例FileSplitterFetch *jy"g64j  
//启动FileSplitterFetch线程 j)jt&Gg'  
//等待子线程返回 ,\PTn7_  
try{ K$ |!IXs  
if(bFirst) ~A>-tn}O  
{ 9kas]zQ%=P  
nFileLength = getFileSize(); y)`q% J&  
if(nFileLength == -1) pf_`{2.\uO  
{ Wp= &nh  
System.err.println("File Length is not known!"); XP@&I[J3sI  
} .@Jos^rxgJ  
else if(nFileLength == -2) uU8L93  
{  p;vrPS  
System.err.println("File is not access!"); c=IjR3F  
} liH1r1M  
else p/jAr+XM  
{ 9Cw !<  
for(int i=0;i<nStartPos.length;i++) 95-%>?4  
{ bj+foNvu\  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); *18J$  
} MPJ0>Ly  
for(int i=0;i<nEndPos.length-1;i++) )B Xl|V,  
{ 5R#:ALwX:  
nEndPos = nStartPos[i+1]; Q".p5(<  
} lp]q%P  
nEndPos[nEndPos.length-1] = nFileLength; dcN4N5r  
} S)A;!}RK6  
} Ns[.guWu-  
7FP @ vng  
+|spC  
//启动子线程 \ id(P3M  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; FVoKNaK-  
for(int i=0;i<nStartPos.length;i++) + hMF\@  
{ KRj3??b  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nZkMyRk  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), boIFN;Aq"  
nStartPos,nEndPos,i); q%Lw#f  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M_F4I$V4  
fileSplitterFetch.start(); DOW Z hD  
} T;B/ Wm!x  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :J6FI6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }+ TA+;  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uulzJbV,K  
nEndPos = " + nFileLength); O>arCr=H  
// fileSplitterFetch[nPos.length-1].start(); S >\\n^SbT  
a(+u"Kr z  
i8(n(  
//等待子线程结束 ~ePtK~,dv  
//int count = 0; _v=zFpR  
//是否结束while循环 \1#!% I=.  
boolean breakWhile = false; &d[%  
3+:uV  
3_c4+u"6  
while(!bStop) [[8h*[:  
{ ig:z[k?  
write_nPos(); \&%y4=y<sE  
Utility.sleep(500); v!rOT/I  
breakWhile = true; ut9R] 01:  
ZvW&%*k=  
l)91v"vJ  
for(int i=0;i<nStartPos.length;i++) VV=6v;u`  
{ ]hA]o7 k  
if(!fileSplitterFetch.bDownOver) ;5}y7#4C  
{ R~XNF/QMl  
breakWhile = false; 5?gZw;yiv%  
break; ~2?UEv6  
} &Zm1(k6&K  
} /)xQ# yfX  
if(breakWhile) 0:k MnHn\  
break; 0XrOOYmx  
))#_@CwRr  
BjbpRQ,  
//count++; '3ZYoA%  
//if(count>4) o|c"W}W  
// siteStop(); c jBHczkY  
} t)*A#  
{]:B80I;2  
0'tm.,  
System.err.println("文件下载结束!"); n(el  
} /pnQKy.  
catch(Exception e){e.printStackTrace ();} zH?&FtO  
} ,DWC=:@X  
fm^)u"  
38(|a5  
//获得文件长度 JWs?az  
public long getFileSize() W|[k]A` 2  
{ sh8(+hg  
int nFileLength = -1; T1~,.(#  
try{ q e;O Ox  
URL url = new URL(siteInfoBean.getSSiteURL()); vpqMKyy  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %c,CfhEV%&  
httpConnection.setRequestProperty("User-Agent","NetFox"); 55|.MXzq  
{_*$X  
>{kPa|  
int responseCode=httpConnection.getResponseCode(); JQWW's}  
if(responseCode>=400) v D4<G{  
{ lIL{*q(  
processErrorCode(responseCode); ,V:RE y  
return -2; //-2 represent access is error TGQDt|+Z  
} $^"_Fox]A\  
dq$C COC^F  
3q0^7)m0  
String sHeader; &T/}|3S  
HA%r:Px  
nXF|AeAco  
for(int i=1;;i++) z6J fu:_N!  
{ b'~IFNt*^  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i3\6*$Ug  
//Utility.log(in.readLine()); wPU<jAQyp  
sHeader=httpConnection.getHeaderFieldKey(i); <S%kwS  
if(sHeader!=null) >c:- ;(k  
{ f:K`M W  
if(sHeader.equals("Content-Length")) ; +E@h=?  
{ #pw=HHq*(  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ( -rw]=Qu  
break; /Q[M2DN@  
} }]?U. ]-  
} C:d$   
else #NLLl EE  
break; az ?2  
} $C !Mk  
} 0NWtu]9QC  
catch(IOException e){e.printStackTrace ();} cxQ8/0^  
catch(Exception e){e.printStackTrace ();} 0^{?kg2o_  
-#?p16qz5  
N%&D(_  
Utility.log(nFileLength); spt='!)4  
n/]$k4h  
~.wDb,*  
return nFileLength; wUz)9n 6j  
} qP0_#l&  
j?n:"@!G/  
+~A<&7[}  
//保存下载信息(文件指针位置) #%i-{t+_>  
private void write_nPos() i\?P>:)  
{ p;rG aLo:u  
try{ {1ic* cZS  
output = new DataOutputStream(new FileOutputStream(tmpFile)); nu#_,x<LS  
output.writeInt(nStartPos.length); p@7[w@B\c  
for(int i=0;i<nStartPos.length;i++) (^Kcyag4  
{ D;0xROW8{  
// output.writeLong(nPos); U'acVcD  
output.writeLong(fileSplitterFetch.nStartPos); 1$Pn;jg:  
output.writeLong(fileSplitterFetch.nEndPos); h8!;RN[  
} H-,RzL/  
output.close(); ){oVVLs  
} Uwqm?]  
catch(IOException e){e.printStackTrace ();} a/wkc*}}/  
catch(Exception e){e.printStackTrace ();} \o j#*aL^  
} xBC:%kG~#  
IlcFW  
rn?:utP  
//读取保存的下载信息(文件指针位置) txwTJScg  
private void read_nPos() ZSTpA,+6  
{ lAwOp  
try{ e[@q{.  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mTzzF9n"Y  
int nCount = input.readInt(); Y(]&j`%  
nStartPos = new long[nCount]; ,1YnWy *  
nEndPos = new long[nCount]; #)BdN  
for(int i=0;i<nStartPos.length;i++) k+S 6)BQ7U  
{ &,Xs=Lv mq  
nStartPos = input.readLong(); ;U|^Tsuc`  
nEndPos = input.readLong(); h?:lO3)TL=  
} z AxwM-`  
input.close(); THmX=K4=?  
} ZK[S'(6q  
catch(IOException e){e.printStackTrace ();} }hFjl4`xa  
catch(Exception e){e.printStackTrace ();} o?J>mpC  
} ZC1U  
z.[ Ok  
m dC.M$  
private void processErrorCode(int nErrorCode) B94mh  
{ F=hfbCF5x  
System.err.println("Error Code : " + nErrorCode); uj-q@IKe  
} o " x& F  
[D H@>:"dd  
%L./U$  
//停止文件下载 ?~a M<rcZ  
public void siteStop() N+?kFob  
{ N3nk\)V\E  
bStop = true; R?Q@)POW  
for(int i=0;i<nStartPos.length;i++) WQ]~TGW  
fileSplitterFetch.splitterStop(); 9k^;]jE  
e6f!6a+%  
i%W,Y8\uf*  
} LTY@}o]\U  
} 1px:(8]{  
//负责部分文件的抓取 0=8.8LnN(  
**FileSplitterFetch.java F^=|NlU&%  
*/ 5U[;T]{)e  
package NetFox; v5t`?+e  
y)v'0q  
G2kr~FG  
import java.io.*; 4\?I4|{pC  
import java.net.*; *Df|D/,WE  
Y 1 i!  
nFlj`k<]Y  
public class FileSplitterFetch extends Thread { 'PlKCn`(w  
nYuZg6K  
 jK&kQ  
String sURL; //File URL mLO{~ruu  
long nStartPos; //File Snippet Start Position IrXC/?^h  
long nEndPos; //File Snippet End Position eN%Ks  
int nThreadID; //Thread's ID Y:VM 5r)  
boolean bDownOver = false; //Downing is over I,AI$A  
boolean bStop = false; //Stop identical q5[%B K  
FileAccessI fileAccessI = null; //File Access interface 4kA/W0 VG  
h"YIAQ',  
d*1@lmV*  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZBJYpeGe  
{ b=QO^  
this.sURL = sURL; odquAqn  
this.nStartPos = nStart; 0}Xkj)R,  
this.nEndPos = nEnd; COj50t/  
nThreadID = id; "0g1'az}  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &K`[SX=  
} [6 !/  
{61NLF\0H  
9r7QE&.  
public void run() D|Z,eench  
{ P!m~tu}B  
while(nStartPos < nEndPos && !bStop) @-;-DB]j  
{ :f^O!^N  
1` m ~c  
B\}E v&  
try{ W?'!}g(~  
URL url = new URL(sURL); x-U^U.i@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Uz H)fB  
httpConnection.setRequestProperty("User-Agent","NetFox"); gW6lMyiLb  
String sProperty = "bytes="+nStartPos+"-"; ag?@5q3J}  
httpConnection.setRequestProperty("RANGE",sProperty); L"tj DAV  
Utility.log(sProperty); ^?toTU   
DSy,#yA  
/Yx 1S'5  
InputStream input = httpConnection.getInputStream(); PF!Q2t5c3  
//logResponseHead(httpConnection); f b_tda",}  
eF}Q8]da  
'oEFNC9V  
byte[] b = new byte[1024]; GA6Z{U{XS  
int nRead; r,MgIv(L  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n\*>m p)  
{ ^C):yxN P  
nStartPos += fileAccessI.write(b,0,nRead); t3Q;1#Zf  
//if(nThreadID == 1) 9))%tYN  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ygUvO3Z  
} 0'|#Hi7@  
: O t\l  
h.4;-&  
Utility.log("Thread " + nThreadID + " is over!"); pLBp[GQ  
bDownOver = true; J*,Ed51&7  
//nPos = fileAccessI.write (b,0,nRead); c1CP1 2  
} j>?H^fB  
catch(Exception e){e.printStackTrace ();} _QBd3B %  
} 8+ B.x  
} bg_Zf7{  
UY{ Uo@k9x  
uiE9#G  
//打印回应的头信息 1w+&Y;d|  
public void logResponseHead(HttpURLConnection con) 5]p>& |Ud  
{ }.2pR*W  
for(int i=1;;i++) VrO$SmH  
{ v[r:1T@  
String header=con.getHeaderFieldKey(i); /n?5J`6  
if(header!=null) m2{z  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tJ.LPgfZ  
Utility.log(header+" : "+con.getHeaderField(header)); / vje='[!  
else vo uQ.utl  
break; .(CzsupY_q  
} tmK@Veb*a'  
} TR{8A^XhE8  
\#2,1W@  
?_W "=WpC  
public void splitterStop() )R9>;CuC9?  
{ G5=(3V%  
bStop = true; 1(hgSf1WH  
} qJ"dkT*  
^67P(h  
$NG}YOP)@  
} `z5j  
B Ibcm,YQ  
%'4dg k  
/* jDgiH}  
**FileAccess.java ^bL.|vB  
*//文件访问(定位,写) eiP>?8  
package NetFox; )@1_Dm@0b  
import java.io.*; pwd7I  
wm*`  
=#T6,[5  
public class FileAccessI implements Serializable{ ^o:0 Y}v=  
*M+:GH/5  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8xg:ItJaA0  
RandomAccessFile oSavedFile; )5d&K8@  
long nPos; +*)B;)P  
Kj}hb)HU  
(sJ{27b_  
public FileAccessI() throws IOException _rs!6tp  
{ A_Sl#e  
this("",0);  9<[RXY  
} }#EiL !Pv  
c4L5"_#`x-  
X"iy.@7  
public FileAccessI(String sName,long nPos) throws IOException EW#.)@-  
{ #1u4Hi(x5  
oSavedFile = new RandomAccessFile(sName,"rw"); vh?({A#>.E  
this.nPos = nPos; ^"6xE nA]  
oSavedFile.seek(nPos); 'n!;7*  
} B`RbXk68q  
1/gY]ghL  
;?zb (2  
public synchronized int write(byte[] b,int nStart,int nLen)  >?U (w<  
{ O~fRcf:Q  
int n = -1; ,a^_ ~(C  
try{ _jU6[y|XLh  
oSavedFile.write(b,nStart,nLen); I7BfA,mZ7  
n = nLen; H0tjN&O_  
} )u\"xxcV  
catch(IOException e) q$b/T+-ec  
{ HewVwD<C  
e.printStackTrace (); Zn #ri 8S  
} s( Kf%ZoE  
)]>=Uo  
]Z<{ ~  
return n; s'~_pP  
} qhF/iUE  
Om>6<3n  
JWMIZ{/M  
} g"# R>&P  
_k5KJKvr  
vuDp_p*]S  
/* JguE#ob2  
**SiteInfoBean.java oPzt1Y  
*/ fcJ#\-+E  
package NetFox; `'Z ;+h]  
;EL!TzL:8  
rU.ew~  
public class SiteInfoBean { zFB$^)v"<  
z<^HohT  
tBrd+}e2*  
private String sSiteURL; //Site's URL Q9%N>h9  
private String sFilePath; //Saved File's Path VD36ce9  
private String sFileName; //Saved File's Name _e~EQ[,  
private int nSplitter; //Count of Splited Downloading File <0R?#^XBZB  
u^ngD64  
wF@qBDxg  
public SiteInfoBean() d+2I+O03  
{//nSplitter的缺省值为5 [.Kia >  
//default value of nSplitter is 5 iOki ZN+d>  
this("","","",5); QdC>fy  
} ]0m4esK`  
VCbnS191*  
OWOj|jM  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y3;G<9K2c]  
{ ix7N q7!N  
sSiteURL= sURL; &)xoR4!2  
sFilePath = sPath; bmt2~!  
sFileName = sName; ub,Sj{Mq"  
this.nSplitter = nSpiltter; 2+"#  
@*%5"~F  
@zd)]O]xH?  
} Gt6$@ji4u  
lpSM p  
oxcAKo  
public String getSSiteURL() J]N-^ld\\  
{ L2Gm0 v  
return sSiteURL; ] MUuz'<  
} Eg  w?  
8uT@$ ./  
bE]2:~  
public void setSSiteURL(String value) M5 Pvc  
{ uERc\TZ  
sSiteURL = value; ]dk~C?H  
} lW^RwNcd  
_5.7HEw>/  
1S.nqOfx  
public String getSFilePath() $stJ+uh  
{ J tYnBg?[E  
return sFilePath; #@y4/JS&2  
} 6"jq/Pu  
~Qzm!Po,  
'Ur$jW  
public void setSFilePath(String value) 5p=T*Y  
{ z4{|?0=C  
sFilePath = value; Eer rIV  
} v9M ;W+J  
"hs`Y4U  
#{ `(;83  
public String getSFileName() Nv #vfh9}P  
{ #G9S[J=xe  
return sFileName; Q3z-v&^E9  
} 7z F29gC  
6AZ/whn#  
Pfi '+I`s  
public void setSFileName(String value) bX5>qqB]  
{ 1{nXmtvr  
sFileName = value; Y}nE/bmx&9  
}  eCk}B$ 2  
'y;[ fwo7  
iSIj ?.  
public int getNSplitter() g%RL9-z  
{ e-{k;V7b  
return nSplitter; <K4'|HU/  
} @uT\.W:Q2  
E(TL+o  
193Q  
public void setNSplitter(int nCount) sl/#1B   
{ pjHUlQ   
nSplitter = nCount; .rN 5A+By`  
} g-Z>1V  
} ;wTl#\|w0  
m./lrz  
|910xd`Z  
/* %4+r&  
**Utility.java C4Bh#C  
*/ {!'AR`|  
package NetFox; g4I(uEJk  
*Pw; ;#\B  
7c4\'dt#  
public class Utility { z#bO FVg#  
hof ZpM  
9:YiLoz?  
public Utility() mpXc o *!_  
{ Ay2Vz>{  
Tfs7SC8ta  
pS*vwYA  
} >RF[0s'-  
$S=lm {  
//线程睡眠 [T~O%ly7x&  
public static void sleep(int nSecond) 2x3&o|J  
{ <\2,7K{{+;  
try{ j"J2&Y2  
Thread.sleep(nSecond); 0gfa7+Y  
} >9Ub=tZm  
catch(Exception e) .T4"+FTzP  
{ NaB8cLURp  
e.printStackTrace (); %2bZeZ  
} J/R=O>  
} C x$|7J=O  
nmS3  
//日志 MCL5a@BX)  
public static void log(String sMsg) ykX}T6T  
{ ~A [ Ju%R  
System.err.println(sMsg); bWUo(B#*I  
} c%Kv"Z%f  
m3P%E8<Q#  
$&k zix  
public static void log(int sMsg) vL\wA_z"<H  
{ eP[azC"G[  
System.err.println(sMsg); rK}*Uwut  
} q.uIZ  
} q;t T*B W  
?<xGO@b .  
L;E9"7Jo  
/* [ ecYpE<  
**TestMethod.java 2/qfK+a  
*/ ]}~*uT}>  
package NetFox; i nF&Pv  
O'A''}M  
D8BK/E-  
public class TestMethod { URX>(Y}g9^  
MDl  
`m@06Q  
public TestMethod() yhgHwES"  
{ ///xx/weblogic60b2_win.exe ~\:+y  
try{ HrEZ]iQ@O0  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hY/SR'8  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7PHvsd"]p  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2syKYHV  
fileFetch.start(); Ny p5=  
} ;:8_H0X'K  
catch(Exception e){e.printStackTrace ();} >L?/Ph%d  
K, ?M5n '  
I_'vVbK+>  
} %L<VnY#%u  
Wi hQj  
BLuILE:$  
public static void main(String[] args) s1:UCv-%  
{ $zyY"yWRZ  
new TestMethod(); < yE(p  
} :$dGcX}  
} =>4>Z_q  
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