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http断点续传简单实现(java)

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/* r-Xe<|w  
**SiteFileFetch.java {S: 3 FI  
*/ uV$d7(N}"  
package NetFox; &*:)5F5  
import java.io.*; Fh4w0u*Q  
import java.net.*; ].T;x|  
2?7hUaHX  
_M4v1Hr48  
public class SiteFileFetch extends Thread { pz6- hi7  
=|&"/$+s  
pmD-]0  
SiteInfoBean siteInfoBean = null; //文件信息Bean w7?9e#> Z  
long[] nStartPos; //开始位置 ez:o9)N4  
long[] nEndPos; //结束位置 >W]"a3E  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Iybpk?,M+  
long nFileLength; //文件长度 S^`9[$KH0  
boolean bFirst = true; //是否第一次取文件 Ty|c@X  
boolean bStop = false; //停止标志 U)=Z&($T  
File tmpFile; //文件下载的临时信息 0BP~ 0z  
DataOutputStream output; //输出到文件的输出流 | xI_aYv*  
^V,/4u  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) *>*/|  
public SiteFileFetch(SiteInfoBean bean) throws IOException ?,e:c XhE2  
{ >Pd23TsN  
siteInfoBean = bean; T:~W.3  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));  (mD:[|.  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); tsC|R~wW  
if(tmpFile.exists ()) [_G0kiI}W"  
{ 5@rqU(]<  
bFirst = false; )w?$~q  
read_nPos(); M~Dc5\T  
} 0Lz56e'j  
else AS"|r  
{ C^: &3,  
nStartPos = new long[bean.getNSplitter()]; [>9"RzEl  
nEndPos = new long[bean.getNSplitter()]; iKH T  
} sW3D ( n  
N$\5%  
Kf<_A{s  
ea}KxLC`,  
} A-!qO|E[-  
R$m?&1K  
fTtSx_}3H  
public void run() aNU%OeQA  
{ $,#IPoi~X  
//获得文件长度 lc(iy:z@  
//分割文件 959jp85  
//实例FileSplitterFetch <l/Qf[V  
//启动FileSplitterFetch线程 J` --O(8Ml  
//等待子线程返回 oOSyOD  
try{ ]@T `q R  
if(bFirst) q8v!{Os+#  
{ #l% \}OC  
nFileLength = getFileSize(); w7V W   
if(nFileLength == -1) uQ+$HzxX  
{ / hdl  
System.err.println("File Length is not known!"); 1Nu`@)D0  
} 5)i0g  
else if(nFileLength == -2) gy`qEY~B&  
{ {X"]92+  
System.err.println("File is not access!"); LB+=?Mz V  
} w.- i !Ls  
else b#j5fEY  
{ SntYi0,`  
for(int i=0;i<nStartPos.length;i++) l Nto9  
{ cSDCNc*%  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); L KR,CPz  
} p}X87Zq  
for(int i=0;i<nEndPos.length-1;i++) F4gc_>{|  
{ {0 {$.L  
nEndPos = nStartPos[i+1]; bvTkS EN  
} >9|+F [Fc  
nEndPos[nEndPos.length-1] = nFileLength; 7Wn]l!  
} $>m<+nai'  
} a8c]B/  
Nuq/_x  
V#KM~3e  
//启动子线程 DL{a8t1L  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1_]l|`Po  
for(int i=0;i<nStartPos.length;i++) ?&_\$L[  
{ M/;g|J jM  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <Ux;dekz}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (Cd `~*5  
nStartPos,nEndPos,i); -3 Hq1  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \C|06Bs $  
fileSplitterFetch.start(); Vd~k4  
} ~=*_I4,+r  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =v9;HPiO  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >?<d}9X  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nfB9M1Svn  
nEndPos = " + nFileLength); 5~QB.m,>  
// fileSplitterFetch[nPos.length-1].start(); [%:NR  
S0yT%V  
\SR  
//等待子线程结束 z>~3*a9&  
//int count = 0; eyV904<F  
//是否结束while循环 ysPW<  
boolean breakWhile = false; ^\%%9jY  
9 |Y?#oZ1  
&5<lQ1  
while(!bStop) {]]I4a  
{ +/tD$  
write_nPos(); V>Cf 8>m  
Utility.sleep(500); xm5D$m3#  
breakWhile = true; &-A 7%"  
EzaOg|  
sM K/l @7  
for(int i=0;i<nStartPos.length;i++) I(4k{=\ph]  
{ \8!HZei  
if(!fileSplitterFetch.bDownOver) hAdEq$  
{ YX(%jcj*  
breakWhile = false; [(mq8Nb  
break; ?}.(k/  
} g@L4G?hLn  
} M}>q>  
if(breakWhile) aum,bm/0J  
break; =Ao;[j)*!  
EMo6$(  
\?Z dUY  
//count++; V*N9D>C  
//if(count>4) V4>P8cE  
// siteStop(); G+}LLm.wX  
} @N$r'@  
tXx9N_/  
|w5#a_adM  
System.err.println("文件下载结束!"); 19EU[eb  
} DCm;dh  
catch(Exception e){e.printStackTrace ();} M\%{!Wzo8  
} C"}x=cK  
_F,OS<>  
g 0L 4  
//获得文件长度 [q z6_WOo  
public long getFileSize() ">o/\sXeH  
{ (R, eWWF8~  
int nFileLength = -1; x[X.// :  
try{ }fA3{ Ro  
URL url = new URL(siteInfoBean.getSSiteURL()); &Fi8@0Fh  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /c7j@=0  
httpConnection.setRequestProperty("User-Agent","NetFox"); ~?p > L  
P/_XDP./U  
X}ZOjX!  
int responseCode=httpConnection.getResponseCode(); UaBR;v-.B3  
if(responseCode>=400) ;9~z_orNQZ  
{ `XnFc*L 1  
processErrorCode(responseCode); U{x'@/Ld  
return -2; //-2 represent access is error Xk3Ufz]QN  
} v6GWD}HH,  
LV[4zo]=  
^ey\ c1K  
String sHeader; Hq~ 2,#Ue  
@.0,k a,X  
sOJ~PRA  
for(int i=1;;i++) ] !H<vR$8  
{ rEViw?^KT  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D"hiEz  
//Utility.log(in.readLine());  4@5<B  
sHeader=httpConnection.getHeaderFieldKey(i); ql4T@r3l}3  
if(sHeader!=null) 5u&jNU5m_  
{ R[Rs2eS_  
if(sHeader.equals("Content-Length")) r}991O<  
{ kSDV#8 uZ  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5mV'k"Om#"  
break; czp5MU_^  
} ZpdM[\Q-  
} CI,-q i  
else !>+ 0/   
break; ka5>9E  
} `S VR_  
} R6!3Y/Q@  
catch(IOException e){e.printStackTrace ();} Y,a.9AWw)  
catch(Exception e){e.printStackTrace ();} ^,X+ n5q;m  
H1w;Wb1se  
eI[z%j[Y*  
Utility.log(nFileLength); }A#FGH +  
a}fW3+>  
^8 z*f&g  
return nFileLength; Cr&ua|%F  
} 1?*vqdt  
f ZISwr  
*8Lym,]  
//保存下载信息(文件指针位置) ]/a?:24[  
private void write_nPos() @<Y Za$`  
{ ~(^[TuJC  
try{ iD\joh-C  
output = new DataOutputStream(new FileOutputStream(tmpFile)); GY!&H"%  
output.writeInt(nStartPos.length); {S}/LSNB  
for(int i=0;i<nStartPos.length;i++) -uh/W=Q1R  
{ c>^_4QQ  
// output.writeLong(nPos); WcdU fv(>  
output.writeLong(fileSplitterFetch.nStartPos); T^79p$  
output.writeLong(fileSplitterFetch.nEndPos); EH[?*>+s  
} )~J/,\  
output.close(); Q:-/@$&i  
} Ah"Rx A  
catch(IOException e){e.printStackTrace ();} L4dbrPE*0  
catch(Exception e){e.printStackTrace ();} M_PL{  
} :s4CWE d  
MXhS\vF#m  
?GFVV->i  
//读取保存的下载信息(文件指针位置) )~Q$ tM`  
private void read_nPos() Ao,lEjNI  
{ w0.#/6  
try{ k'{lo _  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3U}z?gP[  
int nCount = input.readInt(); ?=\h/C  
nStartPos = new long[nCount]; =\q3;5[  
nEndPos = new long[nCount]; )Ev [o#y  
for(int i=0;i<nStartPos.length;i++) UgUW4x'+  
{ * "E]^wCn  
nStartPos = input.readLong(); 0wc+<CUW  
nEndPos = input.readLong(); Q8P;AN_JS  
} $k!t&G  
input.close(); Y!SD^Ie7!  
} oc15!M3$  
catch(IOException e){e.printStackTrace ();} I*0 W\Qz@  
catch(Exception e){e.printStackTrace ();} f[X>?{q  
} <=0_[M  
L 5>>gG ,  
M#:Mwa$  
private void processErrorCode(int nErrorCode) ;z&p(e  
{ 9zX\i oT  
System.err.println("Error Code : " + nErrorCode); #-@dc  
}  - @  
jdhhvoQ  
OnD+/I  
//停止文件下载  Z3I<  
public void siteStop() t4,6`d?C  
{ H >RGX#|  
bStop = true; ysSEgC3  
for(int i=0;i<nStartPos.length;i++) f}@]dFr  
fileSplitterFetch.splitterStop(); [jafPi(#g  
8(ZQD+U(9F  
T,;6q!s=  
} r R."_Z2  
} yy%J{;  
//负责部分文件的抓取 p[W8XX  
**FileSplitterFetch.java fIFB"toiPE  
*/ ZZ4W?);;  
package NetFox; X3'z'5  
]0\8g=KK  
Iy"   
import java.io.*; $rf5\_G,96  
import java.net.*; n#m )]YQC  
u dH7Q&"  
d]+g3oy `  
public class FileSplitterFetch extends Thread { YKj7~yK?  
6n<:ph,h;  
Ll&Y_Ry  
String sURL; //File URL ;@Ls "+g  
long nStartPos; //File Snippet Start Position IspY%UMl  
long nEndPos; //File Snippet End Position ( 2<0kqj%  
int nThreadID; //Thread's ID /SZsXaC '  
boolean bDownOver = false; //Downing is over 4,FuQ}  
boolean bStop = false; //Stop identical I2D<~xP~2+  
FileAccessI fileAccessI = null; //File Access interface fNQ.FAK":  
E@t^IGD r  
e PlEd'Z  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @| r*yi  
{ ~,dj)x 3M  
this.sURL = sURL; RaG-9gujI  
this.nStartPos = nStart; nz+DPk["  
this.nEndPos = nEnd; .LdLm991,Y  
nThreadID = id; ;clF\K>  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =XyK/$  
} Gv3a<Knn4  
G{YLyl/9  
7@MVInV9  
public void run() irpO(>LK  
{ |Q.t]TR'P  
while(nStartPos < nEndPos && !bStop) 6i,d|  
{ hyFq>XFo  
EcFYP"{U  
y~''r%]   
try{ <#LH L  
URL url = new URL(sURL); _q M'm^z5  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3,W2CN}  
httpConnection.setRequestProperty("User-Agent","NetFox"); |$^,e%bE  
String sProperty = "bytes="+nStartPos+"-"; {WT"\Xj>B?  
httpConnection.setRequestProperty("RANGE",sProperty); 7[^:[OEE  
Utility.log(sProperty); 8Q?)L4.]  
 E~jNUTq  
cBiv=!n  
InputStream input = httpConnection.getInputStream();  &EV|knW  
//logResponseHead(httpConnection); 9kWyO:a_(  
"pQM$3n(  
s>E4.0[I%  
byte[] b = new byte[1024]; JaiYVx(  
int nRead; o~2bk<]z  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *!Vic#D%  
{ tbl!{Qwx  
nStartPos += fileAccessI.write(b,0,nRead); i=]IUjx<  
//if(nThreadID == 1) C.FGi`rrm  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dGr Ow)  
} qXCl6Yo8  
{.DI[@.g  
45W:b/n\  
Utility.log("Thread " + nThreadID + " is over!"); ?20y6c<  
bDownOver = true; r"zW=9 O=  
//nPos = fileAccessI.write (b,0,nRead); WQ|d;[E  
} &7XB $  
catch(Exception e){e.printStackTrace ();} cg}46)^<QH  
} !nU  
} 2P"@=bYT"  
7a-> "W  
*(& J^  
//打印回应的头信息 p$0;~1vH  
public void logResponseHead(HttpURLConnection con) :DR G=-M  
{ 8~Rja  
for(int i=1;;i++) vFV->/u  
{ N|WnUlf]:  
String header=con.getHeaderFieldKey(i); [="moh2*f  
if(header!=null) Yono8M;9*  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {uDL"~^\  
Utility.log(header+" : "+con.getHeaderField(header)); oy;N3  
else plv"/KJM  
break; 8n,i5>!d  
} s[SzE6eQ`l  
} pIqPIuy  
axxd W)+K  
3Yp_k  
public void splitterStop() jgs kK  
{ ghx8dX}  
bStop = true; +[zrU`!@  
} LyS139P$  
0v,DQJ?w8  
Mw\/gm_3  
} L`V6\Ix(I  
v}M, M&?  
vpMNulXb,  
/* a+{YTR>0m  
**FileAccess.java >6@*%LM  
*//文件访问(定位,写) 3 B KW  
package NetFox; qF%wl  
import java.io.*; 3Nsb@0  
/ZvNgaH5M  
Rl=NVo  
public class FileAccessI implements Serializable{ H]mY6D51"  
o{ f n}  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7: J6 F  
RandomAccessFile oSavedFile; jQ4Pv`  
long nPos; X. UN=lu  
1;?b-FEq:  
U :J~O y_Z  
public FileAccessI() throws IOException O8[dPm W  
{ j0kEi+!TVq  
this("",0); '355Pce/  
} 7>9/bB+TL  
c42p>}P[  
8T&m{s  
public FileAccessI(String sName,long nPos) throws IOException &rq7;X  
{ H-1@z$p  
oSavedFile = new RandomAccessFile(sName,"rw"); ?Xlmt$Jp  
this.nPos = nPos; P+%O]v1 Ob  
oSavedFile.seek(nPos); 1k-^LdDj  
} o5BOe1_Pw  
2a (w7/W:  
x|F6^d   
public synchronized int write(byte[] b,int nStart,int nLen) Jn' q'+  
{ zblh_6  
int n = -1; K%2,z3ps  
try{ QEQ8gfN9>  
oSavedFile.write(b,nStart,nLen); P2 !~}{-  
n = nLen; M\enjB7k  
} 8p-5.GU)<e  
catch(IOException e) _@F4s   
{ wAF>C[<\  
e.printStackTrace (); v$+G_@  
} a_x$I? ,  
sN5 x\9U  
sOz jViv  
return n; p%xo@v(  
}  T~ /Bf  
I@pnZ-5  
C/<fR:`c  
} lY?TF  
e}(. u1  
jcXb@FE6  
/* gS4K](KH |  
**SiteInfoBean.java UF D_  
*/ $daI++v`  
package NetFox; N]KqSpPh  
X H{5E4P  
43,- t_jV  
public class SiteInfoBean { 8%arA"#S  
,(OA5%A9zK  
6;*tw i  
private String sSiteURL; //Site's URL ;9,Ll%Lk<  
private String sFilePath; //Saved File's Path \<i#Jn+)  
private String sFileName; //Saved File's Name (0Hhn2JA  
private int nSplitter; //Count of Splited Downloading File ;6fkG/T  
q'C'S#qqn  
 4>0xS -  
public SiteInfoBean() n." j0kc7=  
{//nSplitter的缺省值为5 1V FAfv%}  
//default value of nSplitter is 5 Y($"i<rN  
this("","","",5); + #S]uC  
} !%T@DT=l&  
'ZL)-kbI  
/3FC@?l w4  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9 r+' o#  
{ z#D@mn5\ a  
sSiteURL= sURL; x*Z"~'DI  
sFilePath = sPath; CDU^X$Q  
sFileName = sName; 3zs~ Y3M?i  
this.nSplitter = nSpiltter; A3C<9wXx  
m feyR  
Tg{d#U_qB  
} bL swq  
2s|[!:L5  
FIC 2)  
public String getSSiteURL() &EA4`p  
{ 4A|5eg9N  
return sSiteURL; Kc{fT^E  
} `A&64D  
h=d&@k\g  
v,Ep2$  
public void setSSiteURL(String value) ]E[Mv} =  
{ !Aj_r^[X`  
sSiteURL = value; `S$BBF;  
} /SlCcozFL~  
al#yc  
Rjm5{aa-  
public String getSFilePath() z~z.J ]  
{ cN&b$ 8O=%  
return sFilePath; PS(LD4mD  
} O23f\pm&  
2)4{  
&qrH  
public void setSFilePath(String value) `(*5yXC  
{ &W".fRH_O  
sFilePath = value; 7/Ve=7]  
} EG<K[t  
Hr96sN.R   
/+02 BP  
public String getSFileName() 7th&C,c&  
{ x<9|t(  
return sFileName; {,P&05iSi  
} L7a+ #mGE  
+de.!oY  
!C#q  
public void setSFileName(String value) 0r:8ni%cL  
{ X} 8rrC=  
sFileName = value; N @]*E  
} 4vE,nx=  
?$=N!>P#  
i aP+Vab  
public int getNSplitter() P%%Cd  
{ d-xKm2sH  
return nSplitter; 8c]\4iau  
} N \A)P  
!7^fji  
Q$V xm+  
public void setNSplitter(int nCount) "6Ly?'H K  
{ 1c?,= ;>  
nSplitter = nCount; 8l;0)`PU  
} NTgk0cq  
} o` ,&yq.  
k{"~G#GwP  
YR~g&E#U^  
/* 3vVhE,1N  
**Utility.java s+Ln>c'|o  
*/ Xo{Ce%L  
package NetFox; z\fD}`^8  
nSgg'I(  
tty 6  
public class Utility { < ~x5{p  
Njz,y}\  
q& 4Z.(  
public Utility() _qJ[~'m<^C  
{ :vX;>SH$p  
H\^5>ccU>V  
q0DoR@  
} ruF+X)  
P%B1dRa  
//线程睡眠 Gash3}+  
public static void sleep(int nSecond) 83;1L:}`  
{ D.R5-  
try{ _.Uz!2  
Thread.sleep(nSecond); Kq6m5A]z  
} r/3 !~??x  
catch(Exception e) i!YZF$|  
{ vAwFPqu  
e.printStackTrace (); Odw SNG  
} J6NQ5S\  
} D95$  
A 7DdUNR  
//日志 ^D oJ='&  
public static void log(String sMsg) S,Zjol%p  
{ fbo64$!hZ  
System.err.println(sMsg); .F)--%  
} ^b>E_u  
90I)"vfW5  
_ [XEL+.  
public static void log(int sMsg) ~LYKt0/W&  
{ (IJf2  
System.err.println(sMsg); hO{@!H$l  
} De:w(Rm  
} },[S9I`p  
Zb);08X  
JR7~|ov  
/* K%Q^2"Eb0  
**TestMethod.java #J^p,6  
*/ { H9pF2C  
package NetFox;  \2eYw.I=  
?ADk`ts~,}  
9n8;eE08  
public class TestMethod { 3%|<U51  
}1;Ie0l=_e  
'*-X 3p  
public TestMethod() HT1bsY 0t  
{ ///xx/weblogic60b2_win.exe mpr["C"l  
try{ jGt'S{  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o~es> ;  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &[RC4^;\V  
SiteFileFetch fileFetch = new SiteFileFetch(bean); :p8JO:g9  
fileFetch.start(); )#*c|.  
} A=h`Z^8\B  
catch(Exception e){e.printStackTrace ();} 9h*$P:S;1v  
)](8 {}wo  
>(%im :_  
} }zLe;1Tx  
0Vy* 0\{S  
/hI#6k8o_  
public static void main(String[] args) %R&3v%$y*  
{ X4%*&L  
new TestMethod(); .iew5.eB+  
} \dufKeiS&a  
} g`J? 2 _]  
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