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http断点续传简单实现(java)

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/* 8=)9ZjfD  
**SiteFileFetch.java .qLX jU  
*/ uSJLIb  
package NetFox; =gC% =  
import java.io.*; Tol V3  
import java.net.*; /[5\T2GI   
GX'S4B  
M?5voV*  
public class SiteFileFetch extends Thread { Ej $.x6:  
U8{^-#(Uz  
_hgGF9  
SiteInfoBean siteInfoBean = null; //文件信息Bean ydMhb367|  
long[] nStartPos; //开始位置 f\FqZ?w  
long[] nEndPos; //结束位置 0v#p4@Z  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 /IlO   
long nFileLength; //文件长度 _FU}IfG>t  
boolean bFirst = true; //是否第一次取文件 3:<[;yo  
boolean bStop = false; //停止标志 F-XMy>9  
File tmpFile; //文件下载的临时信息 *^KEb")$  
DataOutputStream output; //输出到文件的输出流 <sn,X0W  
g'Wr+( A_  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) K#Xl)h}y7  
public SiteFileFetch(SiteInfoBean bean) throws IOException Tv `&  
{ .e4upT GU  
siteInfoBean = bean; 8@ S@^C*F  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ,Iru_=Wk~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ^A=2#j~H\  
if(tmpFile.exists ()) pgW^hj\  
{ %jJIR88  
bFirst = false; Q9c*I,O j  
read_nPos(); N/[!$B0H@  
} nbW.x7  
else \~r_S  
{ 8?rq{&$t  
nStartPos = new long[bean.getNSplitter()]; |n;5D,r0C  
nEndPos = new long[bean.getNSplitter()]; C)~%(< D  
} OnyAM{$g  
T+PERz(  
~>Y^?l  
Q3'P<"u  
} q;#bFPh  
-v:3#9uX)  
'J)9#  
public void run() ;I6C`N  
{ @vL0gzE?nB  
//获得文件长度 y4VO\N!  
//分割文件 !hE F.S  
//实例FileSplitterFetch $KBW{  
//启动FileSplitterFetch线程 `<#O8,7`  
//等待子线程返回  N!Xn)J  
try{ S~W;Ld<>fB  
if(bFirst) efuiFN;  
{ AF, ;3G  
nFileLength = getFileSize(); FxT]*mo  
if(nFileLength == -1) *\_>=sS x;  
{ $h}w: AV:  
System.err.println("File Length is not known!"); gB>AYL%o=  
} iVo-z#  
else if(nFileLength == -2) eep/96G ?  
{ %TO&  
System.err.println("File is not access!"); VF+g+~  
} q^uCZnkb=  
else NZlCn:"  
{ [!Djs![O  
for(int i=0;i<nStartPos.length;i++) -0I&dG-  
{ b!`6s  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); YDZB$?&a  
} c[;A$P= 8.  
for(int i=0;i<nEndPos.length-1;i++) xiL+s-   
{ sGh TP/  
nEndPos = nStartPos[i+1]; JxKd  
} /8u}VYE  
nEndPos[nEndPos.length-1] = nFileLength; :H#D4O8UiH  
} >[~`rOU*|Y  
} ztAC3,r]  
:;IZ|hU  
lanU)+U.  
//启动子线程 I}|E_U1Qj  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9ph>4u(R  
for(int i=0;i<nStartPos.length;i++) (4IP&^j:\  
{ ;kZJnN"y  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q(R -8"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?X\uzu  
nStartPos,nEndPos,i); n]nJ$u1u  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )TBm?VMe  
fileSplitterFetch.start(); =`2jnvx  
} A'"J'q*t  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~Q]/=HK  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mE'HRv  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H_ NoW  
nEndPos = " + nFileLength); n0t+xvNDF_  
// fileSplitterFetch[nPos.length-1].start(); wod(P73?  
i[wnG)  
:f7:@8  
//等待子线程结束 /g8nT1k  
//int count = 0; muDOY~.  
//是否结束while循环 o)Px d  
boolean breakWhile = false; R?dMM  
fJ=(oF=  
R%\<al$O  
while(!bStop) {DE4PE`  
{ X_)I"`  
write_nPos(); "Y"`'U=v  
Utility.sleep(500); 9JeT1\VvHY  
breakWhile = true; Z`Jt6QgW  
BAG#YZB  
nITkgN:s  
for(int i=0;i<nStartPos.length;i++) |x=(}g  
{ ,#9i=gp  
if(!fileSplitterFetch.bDownOver) F>?~4y,b7  
{ "*TP@X?@f  
breakWhile = false; ,Ww.W'#P  
break; bIzBY+P  
} &'/bnN +R  
} 1uEM;O  
if(breakWhile) QtcYFf g  
break; {IF$\{Al  
 .4Mc4'  
<p?oFD_e4  
//count++; 8|u8J0^  
//if(count>4) jN(c`Gb  
// siteStop(); Tt_QAIl  
} ,>nf/c0.  
!<F5W <V  
Gs4t6+Al  
System.err.println("文件下载结束!"); i&<@}:,  
} ] pv!Ll  
catch(Exception e){e.printStackTrace ();} ]4'V59\  
} q4vHsy36  
'$4&q629d  
OLGMy5  
//获得文件长度 @Y ?p-&  
public long getFileSize() 5kHU'D  
{ VkId6k:>6C  
int nFileLength = -1; M"Z/E>ne  
try{ g>a% gVly  
URL url = new URL(siteInfoBean.getSSiteURL()); _UbyhBl  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ACI.{`SrQ=  
httpConnection.setRequestProperty("User-Agent","NetFox"); ?\<Kb|Q  
zs'Jgm.v  
H1 i+j;RN  
int responseCode=httpConnection.getResponseCode(); Y~I0\8s-  
if(responseCode>=400) cet|k!   
{ w;kiH+&  
processErrorCode(responseCode); >#`{(^  
return -2; //-2 represent access is error z)R\WFBW  
} gEmsPk,  
#8%~u+"N  
#wGOlW;R  
String sHeader; [t*-s1cq  
@# . a5  
roIc1Ax:  
for(int i=1;;i++) a,:Nlr3  
{  Sg(\+j=  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _+Uf5,.5yU  
//Utility.log(in.readLine()); {>Qs+]  
sHeader=httpConnection.getHeaderFieldKey(i); COxJ,v(  
if(sHeader!=null) 6rlM\k@!  
{ b8 6c[2  
if(sHeader.equals("Content-Length")) Ng*O/g`%L  
{ xo(>nFjo  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WpkCFp  
break; Hx9lQ8  
} @[5]?8\o  
} /1hcw|cfC  
else BtQqUk#L2  
break; L f;Uv[^c  
} |9)y<}c5oM  
} _1jeaV9@  
catch(IOException e){e.printStackTrace ();} K~qKr<)  
catch(Exception e){e.printStackTrace ();} w3Dqpo8E  
0{stIgB$  
g&/r =U  
Utility.log(nFileLength); V|4k=_-  
.G/RQn]x}  
|KSoS#Y  
return nFileLength; oCKn  
} WVx^}_FD0  
& 5'cN  
/vqsp0e"H  
//保存下载信息(文件指针位置) iP?lP= M  
private void write_nPos() 7V"Jfh4_  
{ H$,wg!kY!  
try{ NH,4>mV$!  
output = new DataOutputStream(new FileOutputStream(tmpFile)); %D ,(S-Uj  
output.writeInt(nStartPos.length); 1Nz#,IdQ  
for(int i=0;i<nStartPos.length;i++) |e2s{J2   
{ fh&Q(:ZU  
// output.writeLong(nPos); !6J+#  
output.writeLong(fileSplitterFetch.nStartPos); Enhrkk  
output.writeLong(fileSplitterFetch.nEndPos); zbDK$g6  
} p0pA|  
output.close(); v5L#H=P  
} TezwcFqH  
catch(IOException e){e.printStackTrace ();} Xs)?PE [  
catch(Exception e){e.printStackTrace ();} 9hhYyqGsO  
} py\/m]  
wNl "y  
8]JlYe  
//读取保存的下载信息(文件指针位置) "g1Fg.o  
private void read_nPos() @nM+*0 $d  
{ >NA{**$0  
try{ bhCAx W  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |3gWH4M4**  
int nCount = input.readInt(); VWMr\]g  
nStartPos = new long[nCount]; -B:O0;f  
nEndPos = new long[nCount]; p8z"Jn2P  
for(int i=0;i<nStartPos.length;i++) ho6,&Bp8  
{ k-$J #  
nStartPos = input.readLong(); c`#4}$  
nEndPos = input.readLong(); ZC&4uNUr  
} Bs<LJzS{V  
input.close(); e!4Kl:  
} 1tH#QZIT  
catch(IOException e){e.printStackTrace ();} z| zd=3c  
catch(Exception e){e.printStackTrace ();} p49T3V  
} ;{"uG>#R  
U5j0i]  
?xo<Fv  
private void processErrorCode(int nErrorCode) 3\5I4#S  
{ }ct*<zj[~u  
System.err.println("Error Code : " + nErrorCode); XKbTj R  
} S@C"tHD  
<##aD3)  
w6[$vib'  
//停止文件下载 o q cu<]  
public void siteStop() ?$4CgN-  
{ \6,Z<.I  
bStop = true; ypY7uYO^"  
for(int i=0;i<nStartPos.length;i++) %? z;'Y7D  
fileSplitterFetch.splitterStop(); L$}'6y/@  
oRl@AhS  
@Hst-H.l<l  
} +/Vzw  
} BWsD~Ft  
//负责部分文件的抓取 bpfSe  
**FileSplitterFetch.java @C5 %`{\  
*/ &0J/V>k  
package NetFox; xf8.PqVNo  
rB3b  
B zr}+J  
import java.io.*; 58/\  
import java.net.*; 2Zw]Uu`sb  
suZ`  
/S%!{;:  
public class FileSplitterFetch extends Thread { |r53>,oR<:  
6 ZVD<C:\  
|( R[5q  
String sURL; //File URL ZRCUM"R_  
long nStartPos; //File Snippet Start Position %l)~C%T  
long nEndPos; //File Snippet End Position r A9Rz^;xa  
int nThreadID; //Thread's ID 9!Vp-bo  
boolean bDownOver = false; //Downing is over b]\V~ZaXG  
boolean bStop = false; //Stop identical ~Nl`Zmn(A|  
FileAccessI fileAccessI = null; //File Access interface aB4L$M8x  
@#| R{5=+  
F2["AkNM  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Rj,M|9Y)o  
{ r7N% onx  
this.sURL = sURL; n`7n5M*  
this.nStartPos = nStart; ,NQ>,}a0  
this.nEndPos = nEnd; x:IY6  l  
nThreadID = id; u2Qs}FX  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /4u:5G  
} 8\8%FSrc  
w7h=vy n?  
AmT*{Fz8  
public void run() tqK}KL  
{ 2&U<Wiu\}  
while(nStartPos < nEndPos && !bStop) Px"K5c*  
{ pXHeUBY.  
&E8fd/s= k  
" qrL:,   
try{ %b`B.A  
URL url = new URL(sURL); 0qD.OF)8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^->vUf7PX  
httpConnection.setRequestProperty("User-Agent","NetFox"); !<MW*7P=  
String sProperty = "bytes="+nStartPos+"-"; =DXvt5G  
httpConnection.setRequestProperty("RANGE",sProperty); IctLhYZ  
Utility.log(sProperty); ]lzOz<0q  
Z(fhH..T`  
8^dsx1U#  
InputStream input = httpConnection.getInputStream(); z50f$!?  
//logResponseHead(httpConnection); gb/M@6/j  
MHKB:t]hA  
t ~"DQq E  
byte[] b = new byte[1024]; _a=f.I  
int nRead; MOW {g\{\  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R|H_F#eVn}  
{ 4lfJc9J  
nStartPos += fileAccessI.write(b,0,nRead); ihdtq  
//if(nThreadID == 1) Vl+,OBy  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); > jDx-H.N  
} 1 +'HKT}  
? /Z hu  
>w=xGb7  
Utility.log("Thread " + nThreadID + " is over!"); E={W^k!Vz:  
bDownOver = true; :WBl0`kW]4  
//nPos = fileAccessI.write (b,0,nRead); f*SAbDE  
}  g8_IZ(%:  
catch(Exception e){e.printStackTrace ();} }ZWeb#\  
} '%"#]  
} p,w6D,h  
Ey "<hAF  
^~dvA)bH  
//打印回应的头信息 +(<}`!9M*  
public void logResponseHead(HttpURLConnection con) v+Q# O[  
{ ".SQ*'Oc  
for(int i=1;;i++) kY6))9 O  
{ -m~[z  
String header=con.getHeaderFieldKey(i); e?D,=A4mV"  
if(header!=null) %C[ ;&  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lEC58`Ws  
Utility.log(header+" : "+con.getHeaderField(header)); P&Q 5ZQb  
else 3It'!R8$  
break; 4n@, p0   
} [Pt5c6L:  
} V-w[\u  
ynN[N(m#  
G{ $Zg  
public void splitterStop() %R{clbbbn  
{ -h8!O+7 .  
bStop = true; }?Y+GT"E  
} }f6x>  
1v&!`^G99j  
? I}T[j  
} z {J1pH_X  
a;Y9wn  
(Rk g  
/* w`Dzk. 2  
**FileAccess.java EF{_-FXY  
*//文件访问(定位,写) -3r&O:  
package NetFox; !lF|90=  
import java.io.*; 6X:- Z 3  
#| 8!0]n'  
T`=N^Ca1!`  
public class FileAccessI implements Serializable{ QE5 85s5  
|[TH ~ o  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N3H!ptn37  
RandomAccessFile oSavedFile; b`K~l'8  
long nPos; B%9[  
E4[\lX$J  
|[ |X  
public FileAccessI() throws IOException [:!#F7O-  
{ 6|LDb"Rvy  
this("",0); >|7&hj$  
} _ #l b\  
eeb 8v:4  
^LT9t2  
public FileAccessI(String sName,long nPos) throws IOException #D+Fq^="P  
{ V|HSIJ#J  
oSavedFile = new RandomAccessFile(sName,"rw"); fC%;|V'Nd  
this.nPos = nPos; >e-XZ2>Sj  
oSavedFile.seek(nPos); 1xq1te)  
} }+#ag:M  
JEBo!9  
D?5W1m]E,s  
public synchronized int write(byte[] b,int nStart,int nLen) |_[mb(<|  
{ 0#*\o1r\p  
int n = -1; 2#W%--  
try{ 7@tr^JykO  
oSavedFile.write(b,nStart,nLen); PLo.q|%  
n = nLen; -R7f/a8  
} ]\ r~"*TZ  
catch(IOException e) x5`q)!<&  
{ e$>5GM  
e.printStackTrace (); N{p2@_fnB  
} !>S' eXt  
QTn-n)AE  
S-f3rL[?  
return n; ^2^ptQj  
} Ha C?,  
U;V. +onv  
@fE^w^K7  
} dEe/\i'r9  
GF/p|I D  
v@t*iDa?7  
/* o!\O)  
**SiteInfoBean.java / V {w<  
*/ :Dr& {3>  
package NetFox; :&or'Yi}  
7L-%5:1%  
G0]n4"~+?  
public class SiteInfoBean { HWefuj  
Bgs~1E@8V  
v\MH;DW^Z  
private String sSiteURL; //Site's URL H`Z4a N  
private String sFilePath; //Saved File's Path {YGz=5^  
private String sFileName; //Saved File's Name G0(c@FBK  
private int nSplitter; //Count of Splited Downloading File O5=ggG  
MZd\.]G@  
rf`Br\g8  
public SiteInfoBean() k=~?!+p7  
{//nSplitter的缺省值为5 h |lQ TT  
//default value of nSplitter is 5 5r+0^UAO:J  
this("","","",5); 1I@4xC #X  
} rL,)Tc|"  
 CMg83  
*xl7;s  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `Eu(r]:W  
{ KqSa"76R  
sSiteURL= sURL; n5JB'F)  
sFilePath = sPath; k0YsAa#6V  
sFileName = sName; f C^l9CRY  
this.nSplitter = nSpiltter; n47=eKd70  
kCwTv:)  
&=?`;K  
} :U:7iP:  
j0%0yb{-^  
Qr<%rU^{.  
public String getSSiteURL() wU ; f   
{ $HXB !$d  
return sSiteURL; p;7 4 +q  
} `HS4(2+C  
wrO>#`Z  
<{U{pCT%  
public void setSSiteURL(String value) @*uX[)  
{ _ <;Q=?'*  
sSiteURL = value; 5j{@2]i  
} `Of wl%G  
5i/E=D  
YDNqWP7s  
public String getSFilePath() Ij #a  
{ VBX# !K1Q  
return sFilePath; @*DIB+K  
} |x6mkSf]ke  
Y1 P[^ws  
:xw3b)KS  
public void setSFilePath(String value) 4{DeF@@  
{ )RYnRC#O  
sFilePath = value; |wJZU  
} )KqR8UO  
=GQ^uVf1  
eCp|QSXE  
public String getSFileName() tqQ0lv^J  
{ mei_aN7zW  
return sFileName; lkfFAwnc  
} VWshFI  
Is@a,k  
O^}v/}d  
public void setSFileName(String value) |"yf@^kdC  
{ * |HZ&}  
sFileName = value; s1vrzze  
} %EGr0R(  
Fd[h9 G  
B~>cNj<  
public int getNSplitter() .gN$N=7<  
{ >J}n@MZ  
return nSplitter; v{2DBr  
} t;!]z-Y>  
JYd7@Msfc  
9*KMbd ^T  
public void setNSplitter(int nCount) T;4` wB8@  
{ Iz )hz9k  
nSplitter = nCount; JblmXqtC  
} m`$>:B  
} lB!vF ~A&  
90T%T2K  
Lq-33#n/  
/* |:9Ir^  
**Utility.java 5}eQaW48  
*/ `xUG|  
package NetFox; 3%R{"Q"  
+%wWSZ<#  
R|1xXDLm*E  
public class Utility { 0HR|aqPo  
ck+b/.gw`  
qon{ g  
public Utility() `4%;qLxngP  
{ 5_)@B]~nM  
3eTrtCe$  
*v rW A  
} !\0F.*   
OB6J.dF[%  
//线程睡眠 [8@kxCq  
public static void sleep(int nSecond) 6z3T?`}Y  
{ Cqgk  
try{ nG"n-$A?<  
Thread.sleep(nSecond); kT^*>=1  
} =4zNo3IvL+  
catch(Exception e) ejklpa ./  
{ Xlv#=@;O]  
e.printStackTrace (); Y}LLOj@L  
} #, Q}NO#vT  
} R zS|dGNQE  
'Y!pY]Z  
//日志 'j,oIqx  
public static void log(String sMsg) Dz`k[mI  
{ jJ a V  
System.err.println(sMsg); ?j/kOD0  
} Wp5]Uk  
aDL)|>"Q  
{'h_'Y`bOQ  
public static void log(int sMsg) #JA}LA"l  
{ QCOLC2I  
System.err.println(sMsg); fcRj  
} dEASvD'  
} Q.,DZp   
z)lM2x>|*  
W+gpr|R2  
/* yl-fbYH  
**TestMethod.java fVe@YqNa  
*/ \M5P+Wk '  
package NetFox; D_d|=i  
}[ ].\G\G  
vwKw?Z0%J  
public class TestMethod { L=,OZ9aA  
<uZPqi||  
K@HQrv<  
public TestMethod() +W9]ED  
{ ///xx/weblogic60b2_win.exe %3M95UZ2  
try{ TPHYz>D]  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2H[ ; v+  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p8=|5.  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Qyz>ZPu}sz  
fileFetch.start(); x;u~NKy  
} 4O!E|/`wO  
catch(Exception e){e.printStackTrace ();} F>N+<Z  
p*|ah%F6N  
vMhYpt?7\  
} :BZMnCfA  
R2w`Y5#`  
&5u BNpH  
public static void main(String[] args) *g1L$FBG  
{ dK.R[ aQ  
new TestMethod(); 6xarYh(  
} iJ)0Y~  
} B7 HQR{t  
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