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http断点续传简单实现(java)

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/* )EB+(c~E  
**SiteFileFetch.java -5  
*/ ,ja!OZ0$  
package NetFox; 0ZwXuq  
import java.io.*; bwhH2^ !  
import java.net.*; BFw_T3}zn  
5PZ!ZO&  
q=->) &D%  
public class SiteFileFetch extends Thread { sM MtU@<x  
&*" *b\  
[m{sl(Q  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^CLQs;zXE  
long[] nStartPos; //开始位置 O<Q8%Az  
long[] nEndPos; //结束位置 ;AJQ2  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 5b/ ~]v  
long nFileLength; //文件长度 nS3Aadm  
boolean bFirst = true; //是否第一次取文件 ]i(/T$?~  
boolean bStop = false; //停止标志 ^wWbW&<Tg  
File tmpFile; //文件下载的临时信息 W;=Ae~  
DataOutputStream output; //输出到文件的输出流 R 39_!  
#0T/^ #  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) P~{8L.w!>W  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5C1EdQ4S0  
{ b9X*2pnWJ  
siteInfoBean = bean; 5z 0VMt  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); p,8~)ic_  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 8 5ET$YV  
if(tmpFile.exists ()) ou-UR5  
{ Z[IM\# "  
bFirst = false; v =y 2  
read_nPos(); I4jRz*Ufe?  
} gep#o$P  
else ~5&4s  
{ uEJ8Lmi  
nStartPos = new long[bean.getNSplitter()]; 0)Ephsw  
nEndPos = new long[bean.getNSplitter()]; o5a=>|?p>  
} 24#qg '  
;_"|#  
7?R600OA  
la+Cra&xL  
} o:Kw<z,$H  
4{F1GW  
m4@NW*G{  
public void run() gEj#>=s  
{ $!>.h*np  
//获得文件长度 e9[72V  
//分割文件 @p*)^D6E\  
//实例FileSplitterFetch wUCxa>h'  
//启动FileSplitterFetch线程 9(TGkz(NA  
//等待子线程返回 ZEI,9`t!  
try{ 1]G)41  
if(bFirst) l{Df{1b.  
{ m@Yc&M~  
nFileLength = getFileSize(); FoK2h!_  
if(nFileLength == -1) WChP,hw  
{ #3qeRl  
System.err.println("File Length is not known!"); p@G7}'|eyA  
} 3>1^$0iq  
else if(nFileLength == -2) OtqFI!ns  
{ lNL=Yu2p_  
System.err.println("File is not access!"); +>q#eUS)  
} g&FTX>wX  
else 2DCQ5XewYe  
{ r+FEgSDa]  
for(int i=0;i<nStartPos.length;i++) RHC ZP  
{ v3-' G gM  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?+d`_/IB  
} GkJcd;  
for(int i=0;i<nEndPos.length-1;i++) Ax=HDW}  
{ k3#'g'>yh  
nEndPos = nStartPos[i+1]; ls@]%pz.1d  
} p +i 1sY  
nEndPos[nEndPos.length-1] = nFileLength; 27eG8  
} kMQ /9~  
} -)}s{[]d6m  
+Dy^4p?o  
5Ml=<^  
//启动子线程 '{d@Gc6.  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )]1hN;Nz  
for(int i=0;i<nStartPos.length;i++) y>a?<*Y+e  
{ _B^zm-}8|B  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {.:$F3T  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C{}_Rb'x  
nStartPos,nEndPos,i); E^i]eK*"  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >c,s}HJ  
fileSplitterFetch.start(); 6TW7E }a.  
} <>3)S`C`p  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A0DGDr PD  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "bo0O7InOV  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *|A QV:  
nEndPos = " + nFileLength); PE%$g\#?  
// fileSplitterFetch[nPos.length-1].start(); !a@)6or  
Y 2 @8B6  
D4=*yP  
//等待子线程结束 USBQEt  
//int count = 0; ]O x5F@  
//是否结束while循环 q\Y4vWg  
boolean breakWhile = false; I^ ?tF'E  
)j_El ]?  
c2npma]DZ  
while(!bStop) &3Zq1o  
{ C ^Y\?2h1  
write_nPos(); Gnkar[oa&  
Utility.sleep(500); THYw_]K  
breakWhile = true; i>F=XE  
YT\@fgBt  
TekUY m!G  
for(int i=0;i<nStartPos.length;i++) jm^.E\_  
{ ~e{ @5.g  
if(!fileSplitterFetch.bDownOver) qLN\%}69/  
{ -#|D>  
breakWhile = false; Wc3z7xK1@  
break;  ?%,NOX  
} "j^i6RS  
} C?<pD+]b_  
if(breakWhile) 6}4})B2  
break; tb3V qFx  
*pKTJP  
PMzPj,  
//count++; d ]P~  
//if(count>4) aLO^>",  
// siteStop(); aB]0?C y9(  
} JB_fS/I  
`Fy-"Uf  
y~SVD@  
System.err.println("文件下载结束!"); t^rw@$"}  
} _P;D.>?  
catch(Exception e){e.printStackTrace ();} ~4~`bT9  
} "/W[gP[y%  
.Mt3e c<  
{0zn~+  
//获得文件长度 \(o"/*  
public long getFileSize() V`V\/s gj  
{ u^80NR  
int nFileLength = -1; FfoOJzf~o  
try{ V>Wk\'h  
URL url = new URL(siteInfoBean.getSSiteURL()); a)qan  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r~4uIUE{  
httpConnection.setRequestProperty("User-Agent","NetFox"); 0 'QWa{dS\  
3*b5V<}'|  
_fGTTw(  
int responseCode=httpConnection.getResponseCode(); D&@]  
if(responseCode>=400) :GHv3hn5  
{ ._mep\#.:  
processErrorCode(responseCode); _VtQMg|u  
return -2; //-2 represent access is error JfY*#({y  
} rqdwQ  
<xOv8IQ|  
uV/5f#)  
String sHeader; vF$i"^;tJ;  
xmW~R*^  
Vz{+3vfra6  
for(int i=1;;i++) c OYD N[k  
{ IK~&`n](>  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Tkbao D  
//Utility.log(in.readLine()); c8RJOc4X  
sHeader=httpConnection.getHeaderFieldKey(i); eI #Gx_mg  
if(sHeader!=null) x0*{oP  
{ G#M)5'Q]U  
if(sHeader.equals("Content-Length")) FR&`R  
{ jG5HW*>k0  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $o^Z$VmL  
break; k9|5TLXq?  
} 4zug9kFK  
} <g4}7l8  
else Hvl n>x@  
break; ]S|FK>U[  
} D:)Wr, 26  
} 7*/{m K)  
catch(IOException e){e.printStackTrace ();} IgT`on3Y  
catch(Exception e){e.printStackTrace ();} {|;a?] ?  
.8hI ad  
/r}L_wI  
Utility.log(nFileLength); 1I +9?fa  
En5oi  
'6KvB  
return nFileLength; *Ak.KBg  
} I7f ^2  
1GY2aZ@  
~5 ^Jv m  
//保存下载信息(文件指针位置) |s|}u`(@9  
private void write_nPos() 9g92eKS  
{ |(7}0]BP0  
try{ <v"o+  
output = new DataOutputStream(new FileOutputStream(tmpFile)); rS8a/d~;0  
output.writeInt(nStartPos.length); DE?v'7cmA  
for(int i=0;i<nStartPos.length;i++) 4<s.|W`  
{ n|`3d~9$&  
// output.writeLong(nPos); \-<BUG]=  
output.writeLong(fileSplitterFetch.nStartPos); GK?ual1  
output.writeLong(fileSplitterFetch.nEndPos); "fFSZ@,r  
} [ oWkd_dK  
output.close(); FLZ9pb[T  
} }d$-:l ,w  
catch(IOException e){e.printStackTrace ();}  EM ,C  
catch(Exception e){e.printStackTrace ();} BD g]M/{  
} Zg;$vIhn  
gN&i &%*!  
8:cbr/F<  
//读取保存的下载信息(文件指针位置) T U%@_vYR  
private void read_nPos() 18g_v"6o  
{ K}*ets1s}  
try{ n:j'0WW  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5*0zI\  
int nCount = input.readInt(); tDByOml8Ix  
nStartPos = new long[nCount]; 3"fDFR  
nEndPos = new long[nCount]; \1EuHQ?  
for(int i=0;i<nStartPos.length;i++) 37AVk`a  
{ j;x()iZ<  
nStartPos = input.readLong(); qHtQ4_Zn;  
nEndPos = input.readLong(); A|A~$v("R  
} OG\i?N  
input.close(); $-4](br|  
} @SQsEq+A?\  
catch(IOException e){e.printStackTrace ();} 'uPAG;)m  
catch(Exception e){e.printStackTrace ();} tjdPi a  
} $:ush"=f8^  
A=|XlP$6  
j50vPV8m  
private void processErrorCode(int nErrorCode) ,GbmL8P7Y  
{ O&%'j  
System.err.println("Error Code : " + nErrorCode); c{#2;k Q,  
} \Lx=iKs<  
HB07 n4 |  
>7U/TVd&  
//停止文件下载 f@*69a8  
public void siteStop() q? ,PFvs"  
{ *X5)9dq  
bStop = true; -YoL.`s1   
for(int i=0;i<nStartPos.length;i++) *D5 xbkH=.  
fileSplitterFetch.splitterStop(); &OR(]Wt0  
U ?[ (  
xJq|,":gj  
} ]xC56se  
} N:j 7J  
//负责部分文件的抓取 {q>%Sr]9  
**FileSplitterFetch.java 2D\ pt  
*/ o |$D|E  
package NetFox; FW]tDGJOw  
wO??"${OH  
*A-_*A  
import java.io.*; A U~DbU0O  
import java.net.*; ^F^g(|(K  
[6GYYu\  
~Xi@#s~  
public class FileSplitterFetch extends Thread { y6(PG:L  
1NYR8W]2  
?Uql 30A  
String sURL; //File URL 7FX4|]  
long nStartPos; //File Snippet Start Position dX(JV' 18A  
long nEndPos; //File Snippet End Position *ug~LK5Y.  
int nThreadID; //Thread's ID 1U\ap{z@  
boolean bDownOver = false; //Downing is over /t5)&  
boolean bStop = false; //Stop identical 1tuvJ+`{  
FileAccessI fileAccessI = null; //File Access interface S-t#d7'B  
n 0!8)Sth  
{C |R@S  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IjI'Hx  
{ *s6 x  
this.sURL = sURL; wt($trJ  
this.nStartPos = nStart; bY_'B5$.^2  
this.nEndPos = nEnd; ;i@S}LwL  
nThreadID = id; 3,PR6a,b'  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I}f`iBG  
} 9QQ XB-  
;m7V]h? R  
PD#,KqL:  
public void run() J4bP(=w!  
{ Emlj,c<?j  
while(nStartPos < nEndPos && !bStop) ;"dX]":  
{ Dka,v  
sXVl4!=l6  
jY6GWsh:9  
try{ 9r%fBiSk  
URL url = new URL(sURL); N{J 1C6  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }:8}i;#M  
httpConnection.setRequestProperty("User-Agent","NetFox"); #GM^:rF  
String sProperty = "bytes="+nStartPos+"-"; ?(ORk|)kU  
httpConnection.setRequestProperty("RANGE",sProperty); (MGg r  
Utility.log(sProperty); Ow 0>qzTg  
@*%3+9`yq  
$6Ma{rC|  
InputStream input = httpConnection.getInputStream(); 0ix(1`Z  
//logResponseHead(httpConnection); }`=7%b`-?  
M9)4ihK  
6_mi9_w  
byte[] b = new byte[1024]; HT<p=o'$Z  
int nRead; *\ii +f-  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "ESc^28  
{ l";Yw]:^  
nStartPos += fileAccessI.write(b,0,nRead); i(~DhXz*T  
//if(nThreadID == 1) sL@\,]Y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =.`\V]  
} ns~]a:1yh  
N~/ 'EaO  
8Lgt  
Utility.log("Thread " + nThreadID + " is over!"); = l(euBb  
bDownOver = true; I\*6 >  
//nPos = fileAccessI.write (b,0,nRead); 4cQP+n  
} 1!uBzO6/$  
catch(Exception e){e.printStackTrace ();} o~$O$  
} x3n9|Uud  
} bM?gAY]mB8  
)N 3^r>(e<  
;nSF\X(;{  
//打印回应的头信息 /3s&??{tv  
public void logResponseHead(HttpURLConnection con)  kN=&"  
{ tz ;3  
for(int i=1;;i++) |_?e.}K  
{ sVx}(J  
String header=con.getHeaderFieldKey(i); gnJ8tuS  
if(header!=null) \'~ E%=Q  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9#9 UzKX#  
Utility.log(header+" : "+con.getHeaderField(header)); Pd7\Q]of  
else ^ ]9K>}  
break; q|*^{(tWs  
} bK:U:vpYm  
} G&S2U=KdV%  
ZR1U&<0c@  
@43psq1  
public void splitterStop() j(%N.f6  
{ z& ;8pZr  
bStop = true; g}MUfl-L  
} a``|sn9  
QIiy\E%  
~,/@]6S&Y  
} .D@J\<,+l  
R;DU68R  
'=0}2sF>  
/* \Th<7WbR6#  
**FileAccess.java mB-,\{)  
*//文件访问(定位,写) m!7%5=Fc  
package NetFox; -,bnj^L  
import java.io.*; zT>!xGTu7~  
2.3_FXSt  
s|p I`  
public class FileAccessI implements Serializable{ ?=&; A  
:|;@FkQ  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $z=%e#(!I  
RandomAccessFile oSavedFile; Uxjc&o  
long nPos; krfXvQJwJ  
?4':~;~  
`<9>X9.+  
public FileAccessI() throws IOException ! AwMD  
{ 6U{A6hH]  
this("",0); `n$Ak5f  
} AYnPxiW|  
r,;ca6>5H  
`=Ip>7T&  
public FileAccessI(String sName,long nPos) throws IOException -+"#G?g  
{ LwB1~fF  
oSavedFile = new RandomAccessFile(sName,"rw"); f30J8n"k  
this.nPos = nPos; G[KjK$.Ts?  
oSavedFile.seek(nPos); kG D_w  
} HJ&P[zV^  
8R*;8y_  
`O6#-<>  
public synchronized int write(byte[] b,int nStart,int nLen) ]c>@RXY'  
{ MtJ-pa~n  
int n = -1; kk78*s {6  
try{ mn@1&#c4y  
oSavedFile.write(b,nStart,nLen); ?L }>9$"  
n = nLen; ZN8j})lE  
} y`RzcXblIZ  
catch(IOException e) /V,xSK9.&  
{ +@ChZ  
e.printStackTrace (); ^$Y9.IH"  
} 1h@qcom9K_  
u[)X="-e#  
=7V4{|ESfy  
return n; ?"@Fq2xgB4  
} TKnWhB/J  
kx&JY9(&#  
SRfh{u  
} eu5te0{G  
CtY-Gs  
<)ZQRE@  
/* llZU: bs  
**SiteInfoBean.java h8(#\E  
*/ ]+:yfDtZd  
package NetFox; D|OGlP  
CmB_g?K  
-`' |z+V  
public class SiteInfoBean { o"JH B  
UIEvwQ  
2_pF#M9  
private String sSiteURL; //Site's URL OH@"]Nc~  
private String sFilePath; //Saved File's Path Vq3NjN!+5  
private String sFileName; //Saved File's Name Iynks,ikA  
private int nSplitter; //Count of Splited Downloading File nWsRa uY  
~DD _n  
yepRJ%mp  
public SiteInfoBean() \oPe" k=  
{//nSplitter的缺省值为5 PzPNvV/o  
//default value of nSplitter is 5 %<kfW&_>w  
this("","","",5); eP2Q2C8g  
} >Cr"q*  
04U|Frc  
@_`r*Tb)dM  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l-w4E"n3  
{ |&@q$d  
sSiteURL= sURL; ]L~z9)  
sFilePath = sPath; }#1.$a  
sFileName = sName; 4PVg?  
this.nSplitter = nSpiltter; ZJ{DW4#t  
3@=<4$  
b]]k\b  
} 7Q/H+)  
.Vt|;P}  
Mzg'$]N  
public String getSSiteURL() ZTTA??}Y  
{ l]|&j`'O  
return sSiteURL; p+P@I7V  
} Lx- %y'P  
E{6ku=2F  
N,w6  
public void setSSiteURL(String value) NATi)A"TZ  
{ |!K&h(J|  
sSiteURL = value; iY>x x~V  
} ]/ !*^;cY(  
f #h0O3  
@16y%]Q-E#  
public String getSFilePath() Oi?Q^ISxP  
{ 26~rEOgJ  
return sFilePath; xF UD9TM  
} d '2JMdbc  
x/1FQ>n:9  
'tTlBf7#  
public void setSFilePath(String value) NH/jkt&F[  
{ fXevr `  
sFilePath = value; ,dba:D= l  
} NTJ,U2  
\nOV2(FAT  
_`Kh8G {e  
public String getSFileName() %/zHL?RqJ  
{ |\B\IPs{%'  
return sFileName; VFV8ik)  
} \yymp70w  
gu3)HCZ  
_6FDuCVD-  
public void setSFileName(String value) ^ &KH|qRrO  
{ ,hK =x  
sFileName = value; N0fE*xo  
} ,,XHw;{  
JK md'ZGw  
|RpZr!3V  
public int getNSplitter() ^R\5'9K!  
{ M]\"]H?  
return nSplitter; ,[m4+6G5  
} 5NSXSR9c  
j@JY-^~K5  
EI9Yv>7d{  
public void setNSplitter(int nCount) i\36 s$\  
{ K6<1&  
nSplitter = nCount; [t^%d9@t  
} bv[*jr;45  
} <.7W:s,f=  
fv3)#>Dgp>  
Y!E| X 3  
/* e ]>{?Z  
**Utility.java '.&,.E&{$  
*/ gp'n'K]  
package NetFox; GLl@ 6S>v  
,@gDY9Q3r/  
\No22Je6d  
public class Utility { 9]8M {L  
Q!%CU8!`&  
7L:R&W6  
public Utility() Y@'1}=`J  
{ sEfGf.  
;Wr,VU]  
1/q iE{NW  
} ]*;+ U6/?  
kqAQrg]n  
//线程睡眠 ]O&A:Us  
public static void sleep(int nSecond) aEZn6k1  
{ s?K4::@Fv  
try{ <Q-ufF85)  
Thread.sleep(nSecond);  WU,72g=  
} tbv6-) Hs  
catch(Exception e) 2|w.A!  
{ Zk;;~ESOU  
e.printStackTrace (); CM's6qhQnn  
} vrW9<{  
} KF-gcRh  
kAk,:a;P  
//日志 U14dQ=~b/  
public static void log(String sMsg) t_VHw'~"  
{ 7iJk0L$]x  
System.err.println(sMsg); :~)Q]G1Nj  
} M[*:=C)H  
izW l5}+'B  
$BBfsaJPT  
public static void log(int sMsg) o-' i)pp  
{ UZX)1?U  
System.err.println(sMsg); &Y=NUDt_  
} Iq}h}Wd  
} S@"=,Xj M  
tw3d>H`  
hA\8&pI;  
/* =<_5gR  
**TestMethod.java /eMZTh*1P  
*/ -MEz`7c~  
package NetFox; Pd;ClMa%  
q(p0#Mk,E  
n*6s]iG V  
public class TestMethod { }Voh5*$E`  
TgB;R5  
Qy/bzO  
public TestMethod() /[IQ:':^  
{ ///xx/weblogic60b2_win.exe EH "g`r  
try{ XP^6*}H.*  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d$,i?d,  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,"VQ 0Z1  
SiteFileFetch fileFetch = new SiteFileFetch(bean); .M{[J]H`t  
fileFetch.start(); @YB\ PVhW  
} pOYtN1uN|  
catch(Exception e){e.printStackTrace ();} jgo@~,5R  
E$>e< T  
2* L/c-  
} (Sv%-8?gs  
>oNk(. %  
`k| nf9_  
public static void main(String[] args) U ^9oc&  
{ a*[\edcHU  
new TestMethod(); F`Y<(]+   
} UQcmHZ+lf  
} (*x "6)`  
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