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http断点续传简单实现(java)

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/* CAJ]@P#Xj+  
**SiteFileFetch.java CGp7 Tx#  
*/ R?D c*,  
package NetFox; GN=ugP 9  
import java.io.*; @OB7TI_/   
import java.net.*; ~BbF:DS  
y~r5KB6w  
d#W>"Cqxqa  
public class SiteFileFetch extends Thread { .7`c(9<  
`B%IHr  
p~evPTHnrX  
SiteInfoBean siteInfoBean = null; //文件信息Bean \46 'j.  
long[] nStartPos; //开始位置 xIb"8,N  
long[] nEndPos; //结束位置 Y0 ?<~Gf  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 U;q GUqI  
long nFileLength; //文件长度 v>!tws5e  
boolean bFirst = true; //是否第一次取文件 {gkY:$xnrG  
boolean bStop = false; //停止标志 N!Cy)HnS\w  
File tmpFile; //文件下载的临时信息 8-_\Q2vG  
DataOutputStream output; //输出到文件的输出流 X$0&tmum  
[AA*B  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) P2t9RCH  
public SiteFileFetch(SiteInfoBean bean) throws IOException )J>-;EYb8  
{ i2y E-sgF  
siteInfoBean = bean; AEw~LF2w  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); T4e-QEH  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); IwZe2$f  
if(tmpFile.exists ()) $:u5XJx  
{ <fm<UO,%  
bFirst = false; 6qF9+r&e ?  
read_nPos(); '<!T'l:R:/  
} wj$WE3Y  
else Oe_*(q&  
{ R\MFh!6sn  
nStartPos = new long[bean.getNSplitter()]; gc[BP>tl\  
nEndPos = new long[bean.getNSplitter()]; =}xH6^It  
} py':UQS*q  
qHf8z;lc  
y7@q]~%  
of<(4<T  
} %-Oo9 2tP  
p O O4fc  
 C4.g}q  
public void run() sqE? U*8.-  
{ ]N4?*S*jd)  
//获得文件长度 JIh:IR(ta  
//分割文件 RbN# dI'  
//实例FileSplitterFetch 9J(jbJ7p  
//启动FileSplitterFetch线程 Pq<]`9/w^w  
//等待子线程返回 )ePQN~#K}  
try{ lG/h[  
if(bFirst) d>-k-X-[  
{ 0)HZ5^J  
nFileLength = getFileSize(); L^%jR=  
if(nFileLength == -1) NU/:jr.W#  
{ ZGgM- O1  
System.err.println("File Length is not known!"); L; (J6p]h  
} T*bBw  
else if(nFileLength == -2) T~G~M/  
{ tEl_a~s*3?  
System.err.println("File is not access!"); a`E1rK'  
} =&-+{txs  
else --BS/L-  
{ C/{%f,rU  
for(int i=0;i<nStartPos.length;i++) %]\IC(q  
{ @";zM&  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); upefjwm  
} Bf+7;4-  
for(int i=0;i<nEndPos.length-1;i++) svj0;x5  
{ u~7 ,v  
nEndPos = nStartPos[i+1]; ~Kll.  
} )|Md"r_B  
nEndPos[nEndPos.length-1] = nFileLength; =H)"t:xE  
}  X0&[cyP!  
} D%,AdR"m  
fKQq]&~ H  
Q3P*&6wA  
//启动子线程 >u/ T`$  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <xO" E%t  
for(int i=0;i<nStartPos.length;i++) wu`P=-  
{ D\9-MXc1  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E5`KUMZkq  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $9PscubM4  
nStartPos,nEndPos,i); gzd)7np B2  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W"&Y7("y  
fileSplitterFetch.start(); ITr@;@}c]  
} vq;_x  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^wTod\y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xu(N'l.7&  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M9dOLM.  
nEndPos = " + nFileLength); U_l#lGA(H  
// fileSplitterFetch[nPos.length-1].start(); }MCJ$=5  
Lju)q6  
x17K8De  
//等待子线程结束 Kq4b`cn{_  
//int count = 0; K'u66%wAL  
//是否结束while循环 }35HKgqX  
boolean breakWhile = false; s:f%=4-7  
)a0%62  
;($"_h  
while(!bStop) m{{ 8#@g  
{ F?*ko,  
write_nPos(); JR^#NefJ  
Utility.sleep(500); N2/t  
breakWhile = true; `zjbyY  
`p\@b~GM  
Lq cHsUFj  
for(int i=0;i<nStartPos.length;i++) riz[AAB  
{ d%w#a3(  
if(!fileSplitterFetch.bDownOver) aA3KJa  
{ C'oNGOEd  
breakWhile = false; ~3r}6,%  
break; Hy| X>Z  
} $#LR4 [Fq  
} }n[<$*W^  
if(breakWhile) k%2Rv4)hU  
break; 2GW.'\D  
OHyBNJ  
^!yJ;'H\  
//count++; ai@hQJ*  
//if(count>4) l?J|Ip2W  
// siteStop(); WIkr0k  
} D N#OLk  
ZGZ+BOFL  
#!RO,{FT  
System.err.println("文件下载结束!"); *Iir/6myM  
} ._A@,]LS}  
catch(Exception e){e.printStackTrace ();} ^Z`?mNq9  
} lVR a{._m  
Kh,zp{  
1?hx/02  
//获得文件长度 %9Y3jB",2  
public long getFileSize() dRu|*s  
{ G ;fc8a[X  
int nFileLength = -1; {-Q=YDR  
try{ Trz41g  
URL url = new URL(siteInfoBean.getSSiteURL()); "o6a{KY(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ux=0N]lc  
httpConnection.setRequestProperty("User-Agent","NetFox"); A$;"9F@  
F!pgec%]'  
*!- J"h  
int responseCode=httpConnection.getResponseCode(); 9W+RUh^W  
if(responseCode>=400) KE*8Y4#9  
{ 7,:$, bL  
processErrorCode(responseCode); pxgVYr.  
return -2; //-2 represent access is error j$mCU?  
} lOJ3_8  
f' 28s*n  
QxS=W2iN  
String sHeader; Qqn9nO9  
C<u<:4^H  
ObIL  w  
for(int i=1;;i++) w/UZ6fu  
{ J_ y+.p- 5  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nBo?r}t4  
//Utility.log(in.readLine()); # @~HpqqR  
sHeader=httpConnection.getHeaderFieldKey(i); qr|v|Ejd~  
if(sHeader!=null) @kmOz(  
{ KCc7u8   
if(sHeader.equals("Content-Length")) @M_p3[c\  
{ "CcdwWM  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >Ndck2@  
break; #cdrobJ  
} ~;uc@GGo  
} ^oYudb^%  
else unZYFA}(  
break; A1uo@W  
} `Eq~W@';Q0  
} MeMSF8zSQ  
catch(IOException e){e.printStackTrace ();} NPY\ >pf  
catch(Exception e){e.printStackTrace ();} f&ri=VJY\T  
U2TR>0l  
 VsR8|Hn$  
Utility.log(nFileLength); L^><APlX  
DJ.n8hne  
4te QG  
return nFileLength; bWEti}kW  
} ;I@@PUnR  
h#o?O k  
\[yg f6#[  
//保存下载信息(文件指针位置) guc[du  
private void write_nPos() \Jy/ a-  
{ }?KfL$@$  
try{ ]sL)[o  
output = new DataOutputStream(new FileOutputStream(tmpFile)); K#_x.: <J  
output.writeInt(nStartPos.length); ecIZ +G)k  
for(int i=0;i<nStartPos.length;i++) & Y Y^Bd#  
{ !wNj;ST*  
// output.writeLong(nPos); 'wm :Xa  
output.writeLong(fileSplitterFetch.nStartPos); M`u&-6  
output.writeLong(fileSplitterFetch.nEndPos); op5G}QZ  
} Tc.k0n%W:b  
output.close(); BK;Gh0mp  
} U?.cbB,  
catch(IOException e){e.printStackTrace ();} Oll,;{<O  
catch(Exception e){e.printStackTrace ();} TP R$oO2  
} f:hsE  
wR]jJb F  
?CU6RC n  
//读取保存的下载信息(文件指针位置) Ww)p&don  
private void read_nPos() yDe6f(D  
{ pB0p?D)n  
try{ O~~WP*N  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BWG*UjP M  
int nCount = input.readInt(); ~>-MVp  
nStartPos = new long[nCount]; .0]\a~x  
nEndPos = new long[nCount]; 6zR9(c:a~  
for(int i=0;i<nStartPos.length;i++) *}<Uh'?  
{ 7uq/C#N  
nStartPos = input.readLong(); 8urX]#  
nEndPos = input.readLong(); QMAineO  
} 2/F";tc\'  
input.close(); i&_&4  
} lNRGlTD%  
catch(IOException e){e.printStackTrace ();} SR8)4:aKW  
catch(Exception e){e.printStackTrace ();} l\t\DX"s_  
} -'%>Fon  
F)n^pT  
1r?hRJ:'  
private void processErrorCode(int nErrorCode) 0+dc  
{ u(W+hdTap=  
System.err.println("Error Code : " + nErrorCode); wY'w'%A?  
} ?_V&~?r   
`G0GWh)`x  
egXbe)ld  
//停止文件下载 :/<SJ({q  
public void siteStop() Q}6!t$Vk  
{ [@;q#.}Z  
bStop = true; ,*MA teD  
for(int i=0;i<nStartPos.length;i++) (<KFA,  
fileSplitterFetch.splitterStop(); xP+`scv*m#  
*l{GD1ZDk  
}p|S3/G?$!  
} 2&o jQhe  
} I6-.;)McO  
//负责部分文件的抓取 0ub0 [A  
**FileSplitterFetch.java >K;DBy*  
*/ =IH~:D\&  
package NetFox; 6 @A'N(I=O  
Mv?$zV"`#  
w Sd|-e  
import java.io.*; ;Y9-0W  
import java.net.*; ?[VL 2dP0  
MP_LdJM1E  
[L ?^+p>  
public class FileSplitterFetch extends Thread { {16]8-pe  
q"9 2][}  
&,8F!)[9  
String sURL; //File URL J5Ovj,[EZ  
long nStartPos; //File Snippet Start Position ;1AX u/  
long nEndPos; //File Snippet End Position m- u0U  
int nThreadID; //Thread's ID slTE.  
boolean bDownOver = false; //Downing is over q/#p ol  
boolean bStop = false; //Stop identical J:Idt}@z  
FileAccessI fileAccessI = null; //File Access interface /nWBol,  
SUC'o"  
E*AI}:or;  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @s.civ!Yk  
{ sXaudT  
this.sURL = sURL; 'zhv#&O  
this.nStartPos = nStart; l9t|@9  
this.nEndPos = nEnd; v|Y ut~  
nThreadID = id; B&L-Lc2  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xQ,My  
} 5RsO^2V:  
/ DG  t  
ItD&L ))  
public void run() ~YRG9TK  
{ oH='\M%+  
while(nStartPos < nEndPos && !bStop) zQ~ax!}R  
{ kt2W7.A 5  
zI,z<-  
 <BiSx  
try{ /Os6i&;  
URL url = new URL(sURL); A9_} RJ9  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !9t,#?!  
httpConnection.setRequestProperty("User-Agent","NetFox"); `n?Rxhkwp  
String sProperty = "bytes="+nStartPos+"-"; dt||nF  
httpConnection.setRequestProperty("RANGE",sProperty); ZA+w7S3  
Utility.log(sProperty); ^).  
K1$   
F}~qTF;H  
InputStream input = httpConnection.getInputStream(); Bwl@Muw  
//logResponseHead(httpConnection); 6UKZ0~R  
5=_bK^Am  
Tx>V$+al  
byte[] b = new byte[1024]; {n\Ai3F-  
int nRead; gY&WH9sp?9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s[bQO1g;*  
{ \IaUsx"#o{  
nStartPos += fileAccessI.write(b,0,nRead); I%:\"g"c  
//if(nThreadID == 1) U#Wg"W{  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WZM  
} UR~s\m  
$f?GD<}?7r  
v>0I=ut  
Utility.log("Thread " + nThreadID + " is over!"); Z`<5SHQd  
bDownOver = true; bH.SUd)  
//nPos = fileAccessI.write (b,0,nRead); H/U.Bg 4  
} v\o m  
catch(Exception e){e.printStackTrace ();} ezb*tN!  
} C#LTF-$])  
} />n!2'!  
$0Ys{m  
\`;1[m  
//打印回应的头信息 ;,/4Ry22j-  
public void logResponseHead(HttpURLConnection con) "H#pN;)+   
{ 5.$/]2VK  
for(int i=1;;i++) @jCMQYR  
{ %xrldn%  
String header=con.getHeaderFieldKey(i); 3i1TBhs6  
if(header!=null) Ae\:{[c_D  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6WX?Xc]$3  
Utility.log(header+" : "+con.getHeaderField(header)); &=]!8z=  
else 3Cgv($xl&  
break; "5204I  
} -tIye{  
} iPdS>e e  
21O@yNpS$  
V :/v r  
public void splitterStop() I?RUVs  
{ I? ="Er[g}  
bStop = true; >n3ig~0d  
} p:V1VHT,  
M`n0 q y  
}kG>6_p?  
} Rl&nR$#  
tOX -vQ  
,xg-H6Xfa{  
/* T|,/C|L  
**FileAccess.java .W\JvPTC  
*//文件访问(定位,写) +%H=+fJ2}  
package NetFox; x_t$*  
import java.io.*; ^ WF_IH&  
 W_6gV  
=ld!=II  
public class FileAccessI implements Serializable{ $_3 )m  
6"?#E[ #[  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !jf!\Uu[U  
RandomAccessFile oSavedFile; ep4?;Qmho  
long nPos; W[R`],x`  
WcQkeh3n  
Po&'#TC1  
public FileAccessI() throws IOException # [ +n(  
{ pedyWA>  
this("",0); T"t.t%(8  
} +:W/=C d(h  
ht#,v5oG>f  
EeH ghq  
public FileAccessI(String sName,long nPos) throws IOException @Ko#nDEq  
{ -/ G#ls|?  
oSavedFile = new RandomAccessFile(sName,"rw"); `n@;%*6/  
this.nPos = nPos; hXvC>ie(i  
oSavedFile.seek(nPos); ;66{S'*[  
} 3-oKY*jO  
Vju/+  
e,Z[Nox  
public synchronized int write(byte[] b,int nStart,int nLen) zJ$U5r/u  
{ <,Pl31g^  
int n = -1; l[i1,4  
try{ [+8*}03  
oSavedFile.write(b,nStart,nLen); }t:* w  
n = nLen; ]TJ258P}  
} /E3~z0  
catch(IOException e) 'y5H%I!  
{ -?l`LbD  
e.printStackTrace (); @-Y,9mM   
} M2;6Cz>,P  
@REMl~"D5  
xs )jO+.  
return n; R#i`H(N  
} 2a;[2':  
W7;RQ  
Al]*iw{  
} O\gVB!x  
&-w.rF@  
]q"y P 0  
/* 7{l~\] 6d  
**SiteInfoBean.java C4GkFD   
*/ r i)`e  
package NetFox; Ms5R7<O.7  
_ 2)QL  
0fLd7*1>  
public class SiteInfoBean { -knP5"TB  
=Ot_P7'5gv  
Gx4{ 9  
private String sSiteURL; //Site's URL )TyP{X>  
private String sFilePath; //Saved File's Path ]826kpq_  
private String sFileName; //Saved File's Name j<6+p r  
private int nSplitter; //Count of Splited Downloading File |j{]6Nu  
sCmN|Q  
aK]AhOG   
public SiteInfoBean() sl"H!cwF  
{//nSplitter的缺省值为5 tK?XU9o  
//default value of nSplitter is 5 7G7"Zule*j  
this("","","",5); pe>?m^gz[  
} Jw>na _FJ  
2kk; z0f  
A`Rs n\  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -%Ce  
{ =d iGuI B  
sSiteURL= sURL; rg=Ym.  
sFilePath = sPath; K`j:F>b  
sFileName = sName; $~j9{*]5  
this.nSplitter = nSpiltter; IxG7eX!  
]>ndFE6kl  
dc_2nF  
} P RNq8nmxC  
; xQhq*  
n ywC]T  
public String getSSiteURL() keG\-f  
{ Dd,i^,4Gj  
return sSiteURL; -1~o~yGE  
} AX'-}5T=  
Ino]::ZJ/  
'1fyBU  
public void setSSiteURL(String value) @,}tY ?>a  
{ M ac?HI  
sSiteURL = value; \zwm:@lG  
} s,pg4nst56  
NxDVU?@p*  
m8G/;V[x  
public String getSFilePath() fU\;\  
{ a,)/D_{1  
return sFilePath; ksJ 1:_  
} ImD&~^-_<  
'NCx<0*  
$ER9u2  
public void setSFilePath(String value) F-M)6&T  
{ 'H4?V  
sFilePath = value; B2KBJ4rI[1  
} FFe{=H,=  
 p: eaZ  
"q!*RO'a  
public String getSFileName() l8 $.k5X  
{ \qlz<   
return sFileName; vlipB}  
} c/:k|x  
\m1^sFMZ  
d2)]6)z6  
public void setSFileName(String value) U[OUIXUi  
{ q}0I`$MU  
sFileName = value; 4Ssy (gt  
} Fey^hx w =  
YfMs~}h,  
 c,M"a  
public int getNSplitter() t<$J 3h/"  
{ ;O 5Iu  
return nSplitter; e p Dp*  
} J83C]2~7  
Kb-m  
VVpJ +  
public void setNSplitter(int nCount) M'oZK  
{ \3%3=:  
nSplitter = nCount; S v#,L8f  
} MZh?MaBz06  
} \:'6_K  
I)0_0JXs  
L/%{,7l<^?  
/* kA)`i`gt  
**Utility.java #XqiXM~^R  
*/ y@7CY-1  
package NetFox; OsVz[wN  
9C7HL;MF  
Fg'{K%t4  
public class Utility { g[~J107%A  
h0$ \JXk  
Nez '1  
public Utility() x{GFCy7  
{ so| U&`G  
<X5ge>.  
$fT#Wva-\d  
} 0>e]i[P.  
%nE%^Enw  
//线程睡眠 l8_RA  
public static void sleep(int nSecond) vq-;wdq?2  
{ _J#oAE5]!  
try{ /F''4%S?E  
Thread.sleep(nSecond); hx/A215L  
} b^()[4M;  
catch(Exception e) Goy[P2m  
{ z(2G"}  
e.printStackTrace (); ~Ga{=OM??  
} A`>^A]%  
} 5~(nHCf>  
w\V<6_[vv.  
//日志 ]"YXa~b  
public static void log(String sMsg) "gDk?w  
{ JE*?O*&|Q  
System.err.println(sMsg); F[F  NtZ  
} olXfR-2>1  
/q7$"wP  
>?G!>kw  
public static void log(int sMsg) ljz=u;O)  
{ EU'rdG*t/R  
System.err.println(sMsg); k)y<iHR_o  
} A1z<2.R  
} Y$j !-l5z  
[ :Sl~  
[D<(xr&N%  
/* r?^L/HGc  
**TestMethod.java }jFRuT;35  
*/ PpNG`_O  
package NetFox; ^EW6}oj[  
/'_Yct=  
hw)z]  
public class TestMethod { J9y}rGO  
g0s4ZI+T  
CDr0QM4k:.  
public TestMethod() LcNI$g;}Yf  
{ ///xx/weblogic60b2_win.exe R? N+./{  
try{ Nd@/U c  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 02(Ob  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c|(Q[=   
SiteFileFetch fileFetch = new SiteFileFetch(bean); $YJi]:3&  
fileFetch.start(); wsc=6/#u  
} 3vQVk  
catch(Exception e){e.printStackTrace ();} m")p]B&i=  
0Jd>V  
AI,E9  
} 300[2}Y]  
9+.3GRt7  
/c4$m3?]  
public static void main(String[] args) L}_VT J  
{ (l(d0g&p>  
new TestMethod(); |Vu`-L'Jz  
} ORXH<;^0y  
} &XXr5ne~C  
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