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http断点续传简单实现(java)

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/* B';6r4I-  
**SiteFileFetch.java F@*+{1R  
*/ /,X[k !  
package NetFox; rDQ!zlg>l  
import java.io.*; ]6{*^4kX  
import java.net.*; :^fcC[$K  
B"v.* %"&/  
m <w "T7  
public class SiteFileFetch extends Thread { s.x&LG  
*0|IXGr  
X*,%&6O*  
SiteInfoBean siteInfoBean = null; //文件信息Bean >TP7 }u|  
long[] nStartPos; //开始位置 V h k _  
long[] nEndPos; //结束位置 `"@g8PWe  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 u&9 r2R959  
long nFileLength; //文件长度 ,N e;kI  
boolean bFirst = true; //是否第一次取文件 i@B[ eta  
boolean bStop = false; //停止标志 [ e8x&{L-_  
File tmpFile; //文件下载的临时信息 ]b=P=  
DataOutputStream output; //输出到文件的输出流 .p=sBLp8  
$ KRI'4  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ~{D[ >j][  
public SiteFileFetch(SiteInfoBean bean) throws IOException c1_5, 1U'  
{ vi|R(&  
siteInfoBean = bean; 1|?05<8  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); x&`~R>5/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); c= x,ijY "  
if(tmpFile.exists ()) ynB_"mg  
{  :Mcu  
bFirst = false; "n: %E  
read_nPos(); RiTa \  
} C:uz6i1  
else _9?I A  
{ 0V{(Ru.O  
nStartPos = new long[bean.getNSplitter()]; 4_UU<GEp  
nEndPos = new long[bean.getNSplitter()]; (^5 7UmFv]  
} t2V0lyeL  
M#4QQ} F.  
JGFt0He]  
^47PLLRP  
} p[@5&_u(z  
g1UGd  
v|ck>_" .  
public void run() v"MX>^/<  
{ UDc$"a}ds{  
//获得文件长度 U^.4Hy&D  
//分割文件 'r@:Cz3e*I  
//实例FileSplitterFetch Hh4 n  
//启动FileSplitterFetch线程 b:(-  
//等待子线程返回 2o9$4{}rG  
try{ 1N\D5g3  
if(bFirst) HeK h>  
{ yg2uC(2  
nFileLength = getFileSize(); Lqp8yVO  
if(nFileLength == -1) o%4Gd~  
{ =rd|0K"(r  
System.err.println("File Length is not known!"); $v`afd y  
} teW6;O_  
else if(nFileLength == -2) X>I)~z}9#  
{ G|m1.=DJm  
System.err.println("File is not access!"); ^Q{Bq  
} ZO7&vF}  
else +xXH2b$wWC  
{ "0EA;S8$8  
for(int i=0;i<nStartPos.length;i++) `$604+G  
{ {u\%hpD_  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); $3d}"D  
} BYM3jXWi0v  
for(int i=0;i<nEndPos.length-1;i++) id?#TqD  
{ &6j<ca  
nEndPos = nStartPos[i+1]; ^#):c`  
} >|o_wO  
nEndPos[nEndPos.length-1] = nFileLength; 2`a q**}  
} 45@]:2j  
} =9G;PVk|  
3p*-tBOO  
W0zbxJKjd  
//启动子线程 s-W[ .r|  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f{lZKfrp  
for(int i=0;i<nStartPos.length;i++) AY SSa 1}  
{ A K/z6XGy  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #Y93y\  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CodSJ,  
nStartPos,nEndPos,i); XMRNuEU  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l+wc '= ]  
fileSplitterFetch.start(); .9|u QEL  
} >J=<bhR  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'ZQWYr9R  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?`zgq>R}w[  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n(lk dw  
nEndPos = " + nFileLength); =/+#PVO  
// fileSplitterFetch[nPos.length-1].start(); @-#T5?  
=Z sGT  
8@M'[jT  
//等待子线程结束 gor <g))\  
//int count = 0; a}d6o;li  
//是否结束while循环 m_!U}!  
boolean breakWhile = false; 0m+8P$)C%  
x7RdZC  
ACjf\4Q  
while(!bStop) (\dK4JJ  
{ Y'Z+, CNf  
write_nPos(); sFb4`  
Utility.sleep(500); sg'NBAo"  
breakWhile = true; E=/[s]@5  
,fnsE^}.U  
TK>{qxt:=  
for(int i=0;i<nStartPos.length;i++) 8,o17}NY,  
{ idJh^YD  
if(!fileSplitterFetch.bDownOver) C%ytkzG_  
{ }`9`JmNM  
breakWhile = false; qSQ@p\O~  
break; .yVnw^gu  
} b4 hIeBI\  
} [U_[</L7  
if(breakWhile) 4w{-'M.B  
break; RI@*O6\/I  
V2yveNz\7  
,w&:_n  
//count++; Sue 6+p  
//if(count>4) bZ# X 9fT  
// siteStop(); 6~W u`  
} Q[s 2}Z!N;  
Y&,rTa  
=w <VT%  
System.err.println("文件下载结束!"); jX|=n.#q  
} DuF7HTN[K  
catch(Exception e){e.printStackTrace ();} 6.Bh3p  
} fr#Qz{  
s#lto0b"8  
S!7g)  
//获得文件长度 <*Y O~S(R  
public long getFileSize() G\1J _al  
{ aqfL0Rg+`  
int nFileLength = -1; Zu=kT}aGg  
try{ 797X71>  
URL url = new URL(siteInfoBean.getSSiteURL()); 9bEM#Hj  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  C6)R#  
httpConnection.setRequestProperty("User-Agent","NetFox"); T _~KxQ  
79z)C35~  
CT}' ")Bm  
int responseCode=httpConnection.getResponseCode(); ZT9IMihV  
if(responseCode>=400) l.7d$8'\  
{ g9qC{x d  
processErrorCode(responseCode); zKJ. Tj W  
return -2; //-2 represent access is error |yAK@ Hl'  
} A7(M,4`6  
u&SZ lkf6%  
,xj3w#`zaf  
String sHeader; Y*\6o7  
kr{)  
&A"e,h(^  
for(int i=1;;i++) 966<I56+  
{ tzNaw %\  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h^d\xn9GT#  
//Utility.log(in.readLine()); 7O461$4v  
sHeader=httpConnection.getHeaderFieldKey(i); `r]TA]D R  
if(sHeader!=null) HZuiVW8  
{ 0h:G4  
if(sHeader.equals("Content-Length")) /=trj5h  
{ {~nvs4X  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jI Z+d;1  
break; *]'qLL7d  
} 9ET/I$n  
} *N'hA5.z  
else nF j-<!  
break; SJOmeN}4)  
} 'f6PjI  
} #~1wv^  
catch(IOException e){e.printStackTrace ();} JE9>8+  
catch(Exception e){e.printStackTrace ();} t]r7cA  
N Z)b:~a  
[88{@)  
Utility.log(nFileLength); ;'hi9L  
)"F5lOA6  
>"bnpYSe  
return nFileLength; -HN%B?}. x  
} K@*rVor{  
E\_W  
j,4,zA1j|  
//保存下载信息(文件指针位置) 'jN/~I  
private void write_nPos() Y!;gQeC  
{ m'SmN{(t  
try{ &:q[-K@!  
output = new DataOutputStream(new FileOutputStream(tmpFile)); N tO?  
output.writeInt(nStartPos.length); p; F2z;#  
for(int i=0;i<nStartPos.length;i++) Kc-Y  
{ {:3.27jQ  
// output.writeLong(nPos); .E#<fz  
output.writeLong(fileSplitterFetch.nStartPos); @Mzz2&(d U  
output.writeLong(fileSplitterFetch.nEndPos); {f&NStiB  
} w/O<.8+  
output.close(); {vLTeIxf.G  
} *$JB`=Q  
catch(IOException e){e.printStackTrace ();} 8i[".9}G\  
catch(Exception e){e.printStackTrace ();} 6#fOCr;f7  
} Q5hb0O%a  
(eki X*y  
>/8ru*Oc  
//读取保存的下载信息(文件指针位置) v;Swo("  
private void read_nPos() c1PViko,>  
{ UBL(Nr  
try{ ;x,+*%  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9jqO/_7R+  
int nCount = input.readInt(); -J{Dxz  
nStartPos = new long[nCount]; 2rF?Q?$,B  
nEndPos = new long[nCount]; V;H d)v( j  
for(int i=0;i<nStartPos.length;i++) dFx2>6AZt  
{ ]NbX`'  
nStartPos = input.readLong(); 4 U}zJP(L  
nEndPos = input.readLong(); g'KzdG`O0  
} LjSLg[i  
input.close(); mVa?aWpez  
} \5t`p67Ve_  
catch(IOException e){e.printStackTrace ();} ,tcP=f dk]  
catch(Exception e){e.printStackTrace ();} yI3Q|731)  
} (W7;}gysh  
w'!ECm>*`  
.4H_Zt[2  
private void processErrorCode(int nErrorCode) KbXbT  
{ bK!,Pc<  
System.err.println("Error Code : " + nErrorCode); u)tHOV>&  
} Q^*G`&w,  
mYiSR   
D8)O4bh  
//停止文件下载 UCe,2v%  
public void siteStop() K5 5} Wi  
{ zt-'SY  
bStop = true; )?F $-~7  
for(int i=0;i<nStartPos.length;i++) y T[Lzv#  
fileSplitterFetch.splitterStop(); {9h`$e=  
/!^L69um  
7vi i9Am7  
} ls[Ls  
} n33JTqX  
//负责部分文件的抓取 [u/zrpTk  
**FileSplitterFetch.java ;%BhhmR)[  
*/ hO^&0?  
package NetFox; 6W)xj6<@  
j5PaSk&o=  
U(rr vNt:t  
import java.io.*; IUluJ.sXIf  
import java.net.*; f %bc64N(  
8|w5QvCU?3  
Bv2z4D4f+  
public class FileSplitterFetch extends Thread { zWF 5m )-  
[ED!J~lg8  
A6{t%k~F  
String sURL; //File URL >&$$(Bp  
long nStartPos; //File Snippet Start Position Rf)'HT  
long nEndPos; //File Snippet End Position 2>!_B\%)H  
int nThreadID; //Thread's ID e*Uz# w:  
boolean bDownOver = false; //Downing is over P]!LN\[  
boolean bStop = false; //Stop identical ]NaMZ  
FileAccessI fileAccessI = null; //File Access interface "2)+)Db  
>Sc$R0  
/Oq1q._9F  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S% JNxT7'  
{ 2uvQf&,  
this.sURL = sURL; ^m6k@VM  
this.nStartPos = nStart; ddUjs8VvJ  
this.nEndPos = nEnd; LVPt*S=/  
nThreadID = id; NWo7wVwc/c  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Fy}MXe"f  
} 3v9gb,)y\  
L eG7x7n  
'#cT4_D^lI  
public void run() o7_MMeQ4  
{ v YRt2({}Z  
while(nStartPos < nEndPos && !bStop) Fpj6Atk  
{ r*X}3t*  
zCKy`u .  
8\qCj.>S  
try{ 7&;[an^w  
URL url = new URL(sURL); d8Q_6(Ar|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R$!;J?SS  
httpConnection.setRequestProperty("User-Agent","NetFox"); s=^r/Sz902  
String sProperty = "bytes="+nStartPos+"-"; |QAeQWP+1  
httpConnection.setRequestProperty("RANGE",sProperty); gFWEodx,9  
Utility.log(sProperty); jMz1s%C  
3b g4#c  
s T :tFK\  
InputStream input = httpConnection.getInputStream(); ]MqH13`)A  
//logResponseHead(httpConnection); *j_fG$10g  
IyG = 7  
D,}'E0  
byte[] b = new byte[1024]; Vq\..!y  
int nRead; lRF_ k  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Se^/VVm  
{ y(c|5CQ  
nStartPos += fileAccessI.write(b,0,nRead); l6&v}M  
//if(nThreadID == 1) an$ ]IN  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rj2r#{[  
} ? BHWzo!  
]v^`+s}3  
ecY ^C3+S  
Utility.log("Thread " + nThreadID + " is over!"); E&iWtwkz  
bDownOver = true; &J6o$i  
//nPos = fileAccessI.write (b,0,nRead); F(KH-  
} F$6])F  
catch(Exception e){e.printStackTrace ();} A]tf>H#1  
} a O"nD_7  
} 9z| >roNe  
Z!*8JaMT  
DK@w^ZW6JA  
//打印回应的头信息 UALg!M#  
public void logResponseHead(HttpURLConnection con) 6PzN>+t^y  
{ DmXDg7y7s  
for(int i=1;;i++) Zv1Bju*y  
{ MuFU?3ovG*  
String header=con.getHeaderFieldKey(i); @R'g@+{I  
if(header!=null) (Qx-KRH  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \c9t]py<.h  
Utility.log(header+" : "+con.getHeaderField(header)); _M"$5 T  
else j?f,~Y<k  
break; !dbA (  
} 80s~ae;  
} w}U5dM`  
^7~SS2t!  
+9Hk+.  
public void splitterStop() _ntW}})K  
{ FQ9csUjpB  
bStop = true; bn*{*=(|  
} _V7^sk!  
MOqA$b  
A=qW]Im  
} J++sTQ(!?  
2=Y_Qrhi  
St3(1mApl  
/* M[ ~2,M&H  
**FileAccess.java 0IPhVG~#  
*//文件访问(定位,写) 8Snq75Q<   
package NetFox; OuBMVn  
import java.io.*; [#Nx>RY  
MR)KLM0  
d'AviW>  
public class FileAccessI implements Serializable{ uu@'02G8  
m|ERf2-  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }d~FTre  
RandomAccessFile oSavedFile; ZTBFV/{  
long nPos; 1&@wb'MBs.  
vU$O{|J  
B'gk/^6$eg  
public FileAccessI() throws IOException [^(R1K  
{ 0ZID @^  
this("",0); F&L?J_=  
} /<?X-IDz.{  
[-Dgo1}Qr  
d T,m{[+  
public FileAccessI(String sName,long nPos) throws IOException 3Ibt'$dK  
{ Ay"2W%([`  
oSavedFile = new RandomAccessFile(sName,"rw"); 1M~:]}*<  
this.nPos = nPos; [;CqvD<S  
oSavedFile.seek(nPos); oIL+@}u7  
} c7nk~K[6  
G}dOx}kT  
&v9PT!R~  
public synchronized int write(byte[] b,int nStart,int nLen) }b ]y 0"  
{ sO4}kxZ  
int n = -1; ;AL@<,8  
try{ Pl5NHVr  
oSavedFile.write(b,nStart,nLen); agxSb^ 8tF  
n = nLen; KlqJ EtO_  
} /qhm9~4e3  
catch(IOException e) ^1Zq0  
{ %qjyk=z+Z  
e.printStackTrace (); ??%T  
} :: 72~'tw  
%J ( }D7-,  
s8_NN  
return n; GwpBDM k  
} M Xt +  
$?A Uk  
_:=OHURc  
} L z>{FOR  
}`/n2  
m6Cd^'J9^  
/* wZ3 vF)2s  
**SiteInfoBean.java [U7,\o4w  
*/ aj'8;E+  
package NetFox; GoVPo'  
}!7DF  
=|V]8 tN  
public class SiteInfoBean { E0B2>V  
|&RX>UW$W  
8YLZ)k'  
private String sSiteURL; //Site's URL H6CGc0NS+  
private String sFilePath; //Saved File's Path X-r,>o:  
private String sFileName; //Saved File's Name nIKT w  
private int nSplitter; //Count of Splited Downloading File DHNii_w4v  
+?txGHQq  
*9{Wn7pck/  
public SiteInfoBean() f5qHBQ  
{//nSplitter的缺省值为5 +ET  
//default value of nSplitter is 5 M j%|'dZz  
this("","","",5); rbZ6V :  
} -L50kk>h  
.,K?\WZ  
$JSC+o(q3#  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /z?7ic0  
{ ;Owu:}   
sSiteURL= sURL; qg:I+"u  
sFilePath = sPath; Y~SlipY_  
sFileName = sName; n*4X/K  
this.nSplitter = nSpiltter; B|$13dHfa  
>A( C9_\  
A*U'SCg(G  
} XaS_3d  
H^1 a3L]  
k^\ &.63(  
public String getSSiteURL() !vp!\Zj7o  
{ j!o3g;j  
return sSiteURL; GfPz^F=ie.  
} ~#km0<r?  
W3/Stt$D  
r<"/P`r  
public void setSSiteURL(String value) GaqG 8% .  
{ j3-6WUO  
sSiteURL = value; >MY.Fr#.m  
} J9c3d~YW  
T*~)9o  
F1*rUsRKN  
public String getSFilePath() ftuQ"Ds  
{ !!O{ ppM  
return sFilePath; et}Y4,:  
} `v2l1CQ: ^  
g*.(! !  
=usDI<3r  
public void setSFilePath(String value) i*w-Q=  
{ yzR=:0J  
sFilePath = value; RAQ;O  
} "$cT*}br  
8"UG&wLT  
.p~;U|h"  
public String getSFileName() VCRv(Ek  
{ q=i<vcw  
return sFileName; hdqls0 r  
} H{zuIN/.1  
oySM?ZE  
U (7P X`1  
public void setSFileName(String value) { (,vm}iFL  
{ ts!aKx  
sFileName = value; IqKXFORiNI  
} Qnx92   
Fe< t@W  
b/Q"j3  
public int getNSplitter() 5mVu]T`  
{ .: ;Hh~  
return nSplitter; "FvlZRfXj  
} 'X<uG x  
{;M/J  
<r3n?w8  
public void setNSplitter(int nCount) (kOv  
{ k T>}(G||  
nSplitter = nCount; y'/9KrV T  
} 6ng g*kE<  
} 08jQq#  
Nj8)HR  
`.WKU"To  
/* Utp\}0GZY  
**Utility.java *3Z#r  
*/ u Aa>6R  
package NetFox; --)[>6)I  
(OJ9@_fgG[  
(5;xs  
public class Utility { f L?~1i =  
dsuW4 ^ l  
S @($c'  
public Utility() h9nCSj  
{ =K8h)B_g  
ka%pS  
n\9*B##  
} KrH ;o)|  
3$;v# P$%N  
//线程睡眠 dUSuhT  
public static void sleep(int nSecond) QNEaj\   
{ '|R|7nQAj  
try{ <:-&yDh u  
Thread.sleep(nSecond); 42LV>X#i  
} D40VJ3TUc  
catch(Exception e) ,Z"sh*  
{ R!CUR~F  
e.printStackTrace (); ZVU)@[s  
} )dcGV$4t[  
} v8N1fuP}  
$y}Tbm  
//日志 Mla,"~4D5  
public static void log(String sMsg) 4HAfTQ 1G  
{ uESHTX/[  
System.err.println(sMsg); 0IuU4h5Fr  
} ]A[~2]  
enM 3  
?zqXHv#x  
public static void log(int sMsg) nr;/:[F  
{ zV#k #/$  
System.err.println(sMsg); [$X(i|6  
} #D8)rs.9  
} Uz_{jAhW]  
>EjBk nl  
nor`w,2VF  
/* &#.&xc2sRZ  
**TestMethod.java i8F~$6C  
*/ o? =u#=  
package NetFox; $[e*0!e  
\)hmg  
wqsnyP/m  
public class TestMethod { UF4QPPH4  
Zzs pE}  
ezeGw?/  
public TestMethod() xhv)rhu@  
{ ///xx/weblogic60b2_win.exe ;F5%X\ t-  
try{ klKt^h-  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -xXM/3g1u  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6|9fcIh]B  
SiteFileFetch fileFetch = new SiteFileFetch(bean); F7d f  
fileFetch.start(); eZHi6v)i  
} X |as1Y$O+  
catch(Exception e){e.printStackTrace ();} O<5bsKw'r  
:iJ= 9  
zKZ6Qjd8!  
} 7)YU ;  
uG<+IT|x  
Sc(2c.HO*  
public static void main(String[] args) ax$0J|}7  
{ i^(0,L  
new TestMethod(); zuOIos  
} >13=4S  
} /#HY-b  
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