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http断点续传简单实现(java)

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/* }_Tt1iai*  
**SiteFileFetch.java 0~Um^q*'3  
*/ s@/B*r9  
package NetFox; #8P#^v]H  
import java.io.*; y>DfM5>  
import java.net.*; 0*/mc96  
5cPSv?x^F@  
z4 GN8:~x  
public class SiteFileFetch extends Thread { nh _DEPMq  
Gw{Gt]liq  
7qCJ]%)b6  
SiteInfoBean siteInfoBean = null; //文件信息Bean  EGp~Vo-  
long[] nStartPos; //开始位置 >1#DPU(g  
long[] nEndPos; //结束位置 >xhd[  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 QC$=Fs5+  
long nFileLength; //文件长度 j<`I\Pmv  
boolean bFirst = true; //是否第一次取文件 23(B43zy  
boolean bStop = false; //停止标志 2hjre3"?  
File tmpFile; //文件下载的临时信息 AAIyr703cQ  
DataOutputStream output; //输出到文件的输出流 7j9D;_(.^$  
s!8J.hD'I  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) V+4k!  
public SiteFileFetch(SiteInfoBean bean) throws IOException r[C3u[  
{ X67C;H+  
siteInfoBean = bean; ~9`^72  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 8:3oH!n  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); [TiT ff&LV  
if(tmpFile.exists ()) m'G?0^Ft  
{ M"$jpBN*  
bFirst = false; #+ 2:d?t  
read_nPos(); .N2nJ/   
} T U"K#V&u  
else Zi[{\7a  
{ y]~+`9  
nStartPos = new long[bean.getNSplitter()]; ~pX(w!^  
nEndPos = new long[bean.getNSplitter()]; Z~-T0Ab-  
} #cSw"A  
($ [r>)TG  
tk3<sr"IQ  
$ ufSNx(F  
} E :'  
D@sx`H(  
IGF37';;  
public void run()  *pS7/ Qe  
{ o3\SO  
//获得文件长度 "tg\yem  
//分割文件 82Z[eo  
//实例FileSplitterFetch aOAwezfYR  
//启动FileSplitterFetch线程 1drqWI~  
//等待子线程返回 3[|:sa8?s  
try{ O3<Y_I^  
if(bFirst) 2]_4&mU  
{ $Z(g=nS>  
nFileLength = getFileSize(); C>k;MvqO  
if(nFileLength == -1) j]ln :?\  
{ yp^[]Mz=  
System.err.println("File Length is not known!"); k_En_\c?p2  
} :xAe<Pq  
else if(nFileLength == -2) yuy+}]uB@  
{ d <|lLNS  
System.err.println("File is not access!"); sBuq  
} ^NnU gj  
else r:8]\RU  
{ mKf>6/s{c  
for(int i=0;i<nStartPos.length;i++) &)"7am(S`  
{ ;f ;*Q>!  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); uz#eO|z@o  
} K#6`LL m  
for(int i=0;i<nEndPos.length-1;i++)  u_[4n  
{ ^*?B)D=,  
nEndPos = nStartPos[i+1]; hklO:,`  
} 3<UDVt@0  
nEndPos[nEndPos.length-1] = nFileLength; r3BDq  
} _'v }=:X  
} t\|K"  
&"H<+>`  
3qxG?G N  
//启动子线程 x4HMT/@AG2  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h2/1S{/n]  
for(int i=0;i<nStartPos.length;i++) 2 Zjb/  
{ ) R a/  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3Ld ;zW  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )zL"r8si  
nStartPos,nEndPos,i); amk42  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \Q?|gfJH  
fileSplitterFetch.start(); M:1F@\<  
} FOUs= E[  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +O!M>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,C'w(af@}  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GZhfA ;O,  
nEndPos = " + nFileLength); EBL,E:_)  
// fileSplitterFetch[nPos.length-1].start(); Z\gg<Q  
CXP $bt}  
3W0E6H"  
//等待子线程结束 8yo6v3JqC  
//int count = 0; neY=:9  
//是否结束while循环 hZ\W ?r  
boolean breakWhile = false; LOb'<R\p  
MCrO]N($b  
DneSzqO"o  
while(!bStop) ]R0A{+]n  
{ #ZnX6=;X  
write_nPos(); : $52Ds!i  
Utility.sleep(500); []N$;~R7  
breakWhile = true; uA/.4 b  
}vxH)U6$q  
:_YG/0%I  
for(int i=0;i<nStartPos.length;i++) qxcBj  
{ g /@yK  
if(!fileSplitterFetch.bDownOver) 0*:hm%g  
{ \A\yuJ=  
breakWhile = false; io33+/  
break; F?,&y)ri  
} c'Tu,-  
} W0T i ^@  
if(breakWhile) `0G.Y  
break; e %v4,8  
(yTz^o$t|  
3(GrDO9^  
//count++; _} 9R}  
//if(count>4) K,,@',  
// siteStop(); %FI6\ |`M  
} w{O3P"N2  
z&vms   
MJ/%$  
System.err.println("文件下载结束!"); K#sb"x`  
} N[bf.5T  
catch(Exception e){e.printStackTrace ();} pr,1Wp0l  
} Oi[9b  
`"b7y(M  
=ObtD"  
//获得文件长度 F*].  
public long getFileSize() PXu<4VF  
{ Tl7:}X<?  
int nFileLength = -1; U+r#Y E.  
try{ 6F&]Mk]V8  
URL url = new URL(siteInfoBean.getSSiteURL()); jv=f@:[`I  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3jeV4|  
httpConnection.setRequestProperty("User-Agent","NetFox"); 32|L $o  
_ * s  
s]8J+8 <uO  
int responseCode=httpConnection.getResponseCode(); "/Q(UV<d  
if(responseCode>=400) 3N*C]  
{ @#Uiy5N  
processErrorCode(responseCode); x&/Syb  
return -2; //-2 represent access is error Ci9wF (<k  
} la{uJ9Iw@}  
$#JVI:  
BOQV X&g%  
String sHeader; _v=WjN  
SWO!E  
4x?u5L 9o  
for(int i=1;;i++) =}GyI_br;8  
{ uWtS83i  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y9y*" :&%  
//Utility.log(in.readLine()); m9w ; a  
sHeader=httpConnection.getHeaderFieldKey(i); IeI% X\G  
if(sHeader!=null) K}3"KC  
{ !enz05VW6.  
if(sHeader.equals("Content-Length")) WM )g(i~(  
{ "57G@NC{n  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $<e .]`R  
break; JU1; /3(  
} 6U9Fa=%>}  
} N_[ Q.HD"  
else o? "@9O?  
break; kGiw?~t=%  
} H>X1(sh#}  
} #|h8u`  
catch(IOException e){e.printStackTrace ();} I>~BkR+u%o  
catch(Exception e){e.printStackTrace ();} {&qsh9ob  
?o5#Ve$-X  
tS|zf,7  
Utility.log(nFileLength); T\CQ  
1V$B^/_  
7$P(1D4  
return nFileLength; ?Cfp=85ea!  
} 'z!#E!i  
! -nm7Q  
Dohe(\C@  
//保存下载信息(文件指针位置) 1Klu]J%  
private void write_nPos() l<_mag/j9o  
{ h,?Yw+#o"  
try{ &?sjeC_  
output = new DataOutputStream(new FileOutputStream(tmpFile)); C)}LV  
output.writeInt(nStartPos.length); 3"D00~  
for(int i=0;i<nStartPos.length;i++) jt?%03iuk  
{ c}s3c >`d  
// output.writeLong(nPos); ui0(#2'h%  
output.writeLong(fileSplitterFetch.nStartPos); * xXc$T  
output.writeLong(fileSplitterFetch.nEndPos); %t.IxMY  
} m|FONQ,@D  
output.close(); tzJtd  
} Ps4A B#3  
catch(IOException e){e.printStackTrace ();} tO3B_zC  
catch(Exception e){e.printStackTrace ();} d0E5;3tQ  
} :u93yH6~8  
481u1  
X]%4QIeS  
//读取保存的下载信息(文件指针位置) SYLkC [0 k  
private void read_nPos() <QLj6#d7Y  
{ sJ()ItU5i  
try{ u)>*U'bM  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k5CIU}H"  
int nCount = input.readInt(); 5X|aa>/  
nStartPos = new long[nCount]; f\w4F'^tj  
nEndPos = new long[nCount]; S@-X?Lu  
for(int i=0;i<nStartPos.length;i++) 'Q,<_ L"  
{ .gg0:  
nStartPos = input.readLong(); HXo'^^}q;  
nEndPos = input.readLong(); wj~8KHan  
} .AS,]*?Zn%  
input.close(); xF0*q  
} l%/,Ef*3  
catch(IOException e){e.printStackTrace ();} hUc |Xm  
catch(Exception e){e.printStackTrace ();} ^T>.04";x  
} 6Z:|"AwC2  
^r$5];n  
k Er7,c  
private void processErrorCode(int nErrorCode) "E#%x{d  
{ .<hv &t  
System.err.println("Error Code : " + nErrorCode); LnIJ wD  
} =2'^ :4Z  
<3OV  
e@Y R/I8my  
//停止文件下载 ]B[Qdn  
public void siteStop() )BDi2: u  
{ VNPd L  
bStop = true; 4f5$^uN$qA  
for(int i=0;i<nStartPos.length;i++) RzRLrfV  
fileSplitterFetch.splitterStop(); ](pD<FfS]'  
.quc i(D  
c8MNo'h  
} $!lxVZ>  
} Ho|n\7$  
//负责部分文件的抓取 q ~lW  
**FileSplitterFetch.java Joj8'  
*/ !s:|Ddv  
package NetFox; '@bA_F(  
9X~^w_cdk  
5E8P bV-l  
import java.io.*; 7)#/I  
import java.net.*; c$;enAf@  
m? hX=  
*']RYu?X  
public class FileSplitterFetch extends Thread { glpdYg *  
up?8Pq*  
<j' #mUzd  
String sURL; //File URL s+11) ~  
long nStartPos; //File Snippet Start Position :OM>z4mQ  
long nEndPos; //File Snippet End Position V{r@D!}  
int nThreadID; //Thread's ID q ^?{6}sy  
boolean bDownOver = false; //Downing is over %/y/,yd  
boolean bStop = false; //Stop identical rO~D{)Nu  
FileAccessI fileAccessI = null; //File Access interface "%Ak[04'  
/~Iy1L#  
O<*iDd`(e  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s*@.qN  
{ KpL82  
this.sURL = sURL; }m?L/Y'}  
this.nStartPos = nStart; wP i=+  
this.nEndPos = nEnd; \wd~ Y  
nThreadID = id; {+MMqJCa  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {*m?t 7  
} E^!%m8--  
`i-&Z`  
C~B^sG@;  
public void run() +^.(3Aw  
{ >jcNo3S  
while(nStartPos < nEndPos && !bStop) sXUM,h8$!+  
{ c-,/qn/  
<8Ad\MU  
%<klz)!t  
try{ 4%p vw;r  
URL url = new URL(sURL); @ 9uwcM1F  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f%af.cR*  
httpConnection.setRequestProperty("User-Agent","NetFox"); x>Kem$z  
String sProperty = "bytes="+nStartPos+"-"; ~b+>o  
httpConnection.setRequestProperty("RANGE",sProperty); pD{Li\LY  
Utility.log(sProperty); SWu=n1J.?H  
.R1)i-^  
iL(E`_I<  
InputStream input = httpConnection.getInputStream(); p|Ln;aYc  
//logResponseHead(httpConnection); 82$^pg>  
Eb*DP_  
2c}kiqi{  
byte[] b = new byte[1024]; 3 . @W.GG8  
int nRead; ?#W>^Za=  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X(8 ]9  
{ #2}S83 k  
nStartPos += fileAccessI.write(b,0,nRead); |YH1q1l  
//if(nThreadID == 1) -n6C~Yx  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ws=J)2q  
} dM QnN[d6  
Ys\l[$_`*  
P)T:6K  
Utility.log("Thread " + nThreadID + " is over!"); E*kS{2NAq  
bDownOver = true; j"f ]pzg&  
//nPos = fileAccessI.write (b,0,nRead); h7g9:10  
} fx*Swv%r  
catch(Exception e){e.printStackTrace ();} fUa`Y ryQ  
} *d@}'De{8  
} Dhq7qz  
ct/I85c@P  
k|w6&k3  
//打印回应的头信息 Bq'hk<ns[  
public void logResponseHead(HttpURLConnection con) I qma vnM#  
{ \PL92HV  
for(int i=1;;i++) ?g9CeeH*  
{ ~Su>^T(?-  
String header=con.getHeaderFieldKey(i); fz:F*zT1  
if(header!=null) m'%F,c)  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^b&aDm~(7  
Utility.log(header+" : "+con.getHeaderField(header)); k%hif8y  
else iXBc ~S  
break; ZM<1;!i  
} 8R)*8bb  
} 7^S&g.A  
!I:6L7HdwB  
<n0-zCf  
public void splitterStop() wj Y3:S~  
{ x *(pr5k  
bStop = true; MYLq2g\  
} !DLIIKO78  
~aBALD0D;  
a "8/y4Y  
} bE0cW'6r  
yBeSvsm  
E-l>z%  
/* ?"J5~_U.  
**FileAccess.java +>{{91mN  
*//文件访问(定位,写) w!%Bc]  
package NetFox; ,OG sx  
import java.io.*; 24]O0K  
g(|p/%H  
/SSl$  
public class FileAccessI implements Serializable{ XYf;72*  
DOf[?vbu  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J/=b1{d"n  
RandomAccessFile oSavedFile; |7%M:7 Q  
long nPos; ~u7a50  
c!E+&5|n  
!%sj-RMvG  
public FileAccessI() throws IOException Q_]O[Kx  
{ yG{'hx6H  
this("",0); 'lg6<M%#[  
} ^\J/l\n  
@>&UoH}2  
s:,BcVLx^  
public FileAccessI(String sName,long nPos) throws IOException |G!-FmIK  
{ Lw1~$rZg  
oSavedFile = new RandomAccessFile(sName,"rw"); `UGHk*DL)  
this.nPos = nPos; sYgpK92  
oSavedFile.seek(nPos); k oZqoP  
} 67%o83\  
g/J ^ YT!  
vaS/WEY  
public synchronized int write(byte[] b,int nStart,int nLen) n:x6bPal]  
{ Em %"] B  
int n = -1; t@.M;b8  
try{ pd/{yX M  
oSavedFile.write(b,nStart,nLen);  UcKpid  
n = nLen; 3I@j=:(%Y  
} _/]4:("  
catch(IOException e) s^)wh v`C  
{ IEmtt^C  
e.printStackTrace (); rs`H':a/  
} R^{Ow  
"O!J6  
7 `thM/fN  
return n; &Vd,{JU  
} $&OoxC  
DfXXN  
2aNCcZw0  
} vdyLwBz:  
t6W$t  
/n"Ib )M  
/* {|9x*I  
**SiteInfoBean.java 'P3CgpF<Z2  
*/ 9~J  
package NetFox; ou0(C `  
7`9J.L&,;  
{=pRU_-^  
public class SiteInfoBean { }'U "HHv  
xPl+ rsU  
A'^y+42jY  
private String sSiteURL; //Site's URL $<xa "aN!  
private String sFilePath; //Saved File's Path !yI , ~`Z  
private String sFileName; //Saved File's Name 5|._K(M  
private int nSplitter; //Count of Splited Downloading File fRS)YE@a:  
@doo2qqIe]  
h&|q>M3  
public SiteInfoBean() .KSPr  
{//nSplitter的缺省值为5 :FcYjw  
//default value of nSplitter is 5 kmXpj3  
this("","","",5); Lf`LFPKb  
} bKRz=$P?  
? BtWM4Id8  
;4tmnC>OnA  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %eW[`uyV  
{ k GR5!8$z  
sSiteURL= sURL; +n_`*@SE  
sFilePath = sPath; *.nC'$-2r  
sFileName = sName; lv\C(^mGq  
this.nSplitter = nSpiltter; F0 x5(lp Q  
G9"2h \  
_?$P?  
} X2^`Znq9  
A14}  
%P05k  
public String getSSiteURL() = zJY5@^'7  
{ 5:ca6 H  
return sSiteURL; MDI[TNYG  
} 9,g &EnvG  
~`-z"zM:p  
|a/1mUxQ&  
public void setSSiteURL(String value) 46^LPC"x  
{ gwHNz5 a*V  
sSiteURL = value; 94Wf ]  
} 2@ 4^ 81  
CDOqdBQ  
5[NF  
public String getSFilePath() 29#&q`J  
{ ;/.ZjTRw  
return sFilePath; /4w"akB|P  
} rWk4)+Tk  
,2hZtJ<A  
ma9VI5w  
public void setSFilePath(String value) U)mg]o-VE  
{ e+J|se4L5  
sFilePath = value; PW a!7n#A  
} "7Qc:<ww  
{p#[.E8  
7I.7%m,g  
public String getSFileName() :i'jQ<|wZN  
{ #IH7WaN  
return sFileName; k8]=5C?k  
}  =FZt  
ZLK@x.=  
6uWzv~!*D  
public void setSFileName(String value) %) A-zzj  
{ cQj{[Wt4  
sFileName = value; \g|u|Y.2[  
} ;Kb]v\C:  
8GC(?#Kb  
("HT0 &#a  
public int getNSplitter() P=ARttT`(  
{ jU K0?S>  
return nSplitter; =l&A9 >\  
} ,]ALyWGuX  
F,B,D^WD  
7=jeq|&kN  
public void setNSplitter(int nCount) )2c[]d /a4  
{ \W73W_P&g  
nSplitter = nCount; G[U'-a}I  
} (bP\_F5D  
} 9p,<<5{  
 gB\ a  
CfFNk "0{  
/* i Rwqt-WZ  
**Utility.java (+g!~MP  
*/ \ ]AsL&  
package NetFox; lqC a%V  
5x/q\p-{/  
2+G_Y>  
public class Utility { HRF4 Ro  
v5i?4?-Z  
wg?:jK  
public Utility() .F=15A  
{ ?&Y3Fr)%  
sePOW#|  
w+vYD2 a  
} *GsrG*OM*D  
.^s%Nh2jM  
//线程睡眠 h 9V9.'  
public static void sleep(int nSecond) _"`wUMee  
{ % ~%>3  
try{ 6"Tr$E  
Thread.sleep(nSecond); A{hwT,zV:  
} ~mUP!f  
catch(Exception e) hk"^3d!  
{ htg+V-,  
e.printStackTrace (); ZgO7W]Z4  
} e=nExY  
} ]2Aqqy  
x9PEYhL?  
//日志 ;8sEE?C$g  
public static void log(String sMsg) LQYT/  
{ x@ bZ((w  
System.err.println(sMsg); zqAK|jbL  
} 6 USet`#  
Ch ` Omq  
d87pQ3e:&  
public static void log(int sMsg) {: EQ  
{ DSix(bs9  
System.err.println(sMsg); m^_)aS  
} Ki-CJ y  
} Ov%9S/d  
Jg|3Wjq5  
S5RS?ya  
/* ^sH1YE}0  
**TestMethod.java *n?6x!A  
*/  ]\P  
package NetFox; FQi"OZHq  
4BuS? #_  
BU:s&+LYUv  
public class TestMethod { cZL"e  
zE.4e&m%Z?  
n*D)RiW  
public TestMethod() I}Q3B3Byg  
{ ///xx/weblogic60b2_win.exe `Pl=%DR  
try{ cJ:BEe  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NLb/Bja  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .(;k]U P  
SiteFileFetch fileFetch = new SiteFileFetch(bean); (B]Vw+/  
fileFetch.start(); SVXey?A;CJ  
} _F^|n}Qbj  
catch(Exception e){e.printStackTrace ();} z!Jce}mx  
?Pmj}f  
}9P)<[>  
} \ox:/-[c\<  
oB9Fas!N  
P9`i6H'~  
public static void main(String[] args) 1[3"|  
{ 2%vwC]A  
new TestMethod(); oF V9t{~j  
} KU33P>a"[k  
} e%'9oAz  
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