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http断点续传简单实现(java)

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/* 2CgIY89O  
**SiteFileFetch.java nzJi)A./  
*/ K/d &c]  
package NetFox; xA'#JN<*  
import java.io.*; K}/`YDu  
import java.net.*; _ N f[HP  
&r5%WRzpYT  
}ZVv  
public class SiteFileFetch extends Thread { d?y\~<  
1nTaKK q  
y$9 t!cx  
SiteInfoBean siteInfoBean = null; //文件信息Bean 'L59\y8H  
long[] nStartPos; //开始位置 {#M{~  
long[] nEndPos; //结束位置 ];~[Olc  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 C{,] 1X6g  
long nFileLength; //文件长度 JU \J  
boolean bFirst = true; //是否第一次取文件 ZV4' |q  
boolean bStop = false; //停止标志 ',s7h"  
File tmpFile; //文件下载的临时信息 :9q^  
DataOutputStream output; //输出到文件的输出流 5N+(Gv[`"  
xWb?i6)z&  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) LF.~rmPa  
public SiteFileFetch(SiteInfoBean bean) throws IOException !;C(pnE  
{ n >PM_W  
siteInfoBean = bean; *xTquV$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); tUF]f6  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); JP@m%Yj  
if(tmpFile.exists ()) ^K8a#-  
{ U9sub6w6  
bFirst = false; s:F+bG}|  
read_nPos(); Q09~vFBg  
} [ \n.[4gq"  
else |F {E4mg(o  
{ ,;pX.Ob U  
nStartPos = new long[bean.getNSplitter()]; )^#Zg8L  
nEndPos = new long[bean.getNSplitter()]; "hY^[@7 W  
} V="f)'S$  
}(}vlL  
* t9qH  
slO9H6<  
} > 0)`uJ  
zGz'2, o3  
;OqLNfU3y  
public void run() @7 HBXP  
{ 8&hn$~ate  
//获得文件长度 NfN6KDd]2L  
//分割文件 *<QL[qyV  
//实例FileSplitterFetch TiEJyd`P  
//启动FileSplitterFetch线程 S%#Mu|  
//等待子线程返回 Eakjsk  
try{ 0%j; yzQ<  
if(bFirst) K :ptfD  
{ Dq 4}VkY  
nFileLength = getFileSize(); Jn&>Z? @  
if(nFileLength == -1) &`2*6 )qa  
{ t1g%o5?;  
System.err.println("File Length is not known!"); @soW f  
} sswAI|6ou  
else if(nFileLength == -2) BTtYlpN6  
{ 8@ g D03  
System.err.println("File is not access!"); -3U} (cZ*  
} LgKEg90w(  
else I3b-uEHev  
{ lfd{O7L0b  
for(int i=0;i<nStartPos.length;i++) Qnh1s u5  
{ iqP0=(^m  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); W\Y 4%y}  
} >&Lu0oHH  
for(int i=0;i<nEndPos.length-1;i++) IQY#EyTb  
{ [c )\?MWW  
nEndPos = nStartPos[i+1]; k-0e#"B  
} o%Q2.  
nEndPos[nEndPos.length-1] = nFileLength; RM$S|y{L  
} scwlW b<N  
} 0k]N%!U  
4yy yXj  
~,1X>N"  
//启动子线程 kIo?<=F8T  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]HT>-Ba;{h  
for(int i=0;i<nStartPos.length;i++) o:ob1G[p%  
{ KJZY.7  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2mG?ve%m)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f 2f $aZ  
nStartPos,nEndPos,i); 13 p0w  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h8;"B   
fileSplitterFetch.start(); 36UW oo  
} FQ^uX]<3j  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,aL"Wy(  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w=2 X[V}  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r${a S@F  
nEndPos = " + nFileLength); |REU7?B  
// fileSplitterFetch[nPos.length-1].start(); k Er7,c  
m!if_Iq  
vUA`V\  
//等待子线程结束 yY|U}]u!V  
//int count = 0; :g_ +{4  
//是否结束while循环 -7Wmq[L /  
boolean breakWhile = false; 1N*~\rV*?  
<{j9|mt  
e@Y R/I8my  
while(!bStop) =z.AQe+   
{ 'KG`{K$  
write_nPos(); V4D&&0&n  
Utility.sleep(500); :{<HiJdp  
breakWhile = true; ^jA}*YP  
r&;AG@N/  
~coG8r"o  
for(int i=0;i<nStartPos.length;i++) euK!JZ  
{ B[h9epU]K  
if(!fileSplitterFetch.bDownOver) cFQa~  
{ dno*Usx5d0  
breakWhile = false; HN%ZN}  
break; =r8(9:F!  
} 54&2SU$kx  
} Joj8'  
if(breakWhile) /8R1$7  
break; :=@[FXD4  
l.! ~t1i  
yE>DQ *  
//count++; 8%B @[YDe  
//if(count>4) ;2}Gqh)Yr  
// siteStop(); TB\CSXb  
} dl4.jLY  
-TWo-iu^  
5`Z#m:+u  
System.err.println("文件下载结束!"); ;MD{p1w  
} z=sqO'~  
catch(Exception e){e.printStackTrace ();}  'M{_S  
} Ws(>} qjy  
h&{pMmS3,  
BHYEd}M  
//获得文件长度 ;.Y`T/eWS  
public long getFileSize() ~qF9*{~!  
{ _{aVm&^kA  
int nFileLength = -1; @lI/g  
try{ 9S^-qQH3}  
URL url = new URL(siteInfoBean.getSSiteURL()); l=yO]a\QZ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 60Z)AQs;+J  
httpConnection.setRequestProperty("User-Agent","NetFox"); )_ uK(UNZ5  
H#D=vx'  
O%I'   
int responseCode=httpConnection.getResponseCode(); w;"'l]W  
if(responseCode>=400) QX4I+x~oo\  
{ &nYmVwi?"Q  
processErrorCode(responseCode); V SxLBwXf  
return -2; //-2 represent access is error +}n]A^&I\E  
} D~Su82 2  
tg:x}n  
<tNx*ce5  
String sHeader; aw`mB,5U  
sC j3h  
q b'ka+X  
for(int i=1;;i++) ]pt @  
{ Onl:eG;@  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q. >"@c[  
//Utility.log(in.readLine()); @S}'_g  
sHeader=httpConnection.getHeaderFieldKey(i);  2r[,w]  
if(sHeader!=null) = FQH  
{ .Qaqkb-Ty  
if(sHeader.equals("Content-Length")) 8LL);"$  
{ ~(c<ioIf  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0Z\fK>yw  
break; lUrchLoDt  
} 3yQ(,k#  
} ,SBL~JJ  
else 0y(d|;':  
break; G100L}d"N  
} k$zDofdfp  
} ,70|I{,Km  
catch(IOException e){e.printStackTrace ();} Y9C]-zEv  
catch(Exception e){e.printStackTrace ();} k~H-:@  
6 ^p 6v   
QeK~A@|F&  
Utility.log(nFileLength); JS4pJe\q  
6^ ~& sA  
Uc&0>_Z  
return nFileLength; CyE.q^Wm  
} .{6TX"M  
?#W>^Za=  
J[9jNCq|  
//保存下载信息(文件指针位置) u5lj+?  
private void write_nPos() g\ke,r6  
{ /];F4AO5  
try{ .w0?  
output = new DataOutputStream(new FileOutputStream(tmpFile)); =U:iR  
output.writeInt(nStartPos.length); \"5\hX~dS  
for(int i=0;i<nStartPos.length;i++) C'{Z?M>  
{ HLS^Ga,(  
// output.writeLong(nPos); 'h:4 Fzo<  
output.writeLong(fileSplitterFetch.nStartPos); 7|2:;5:U  
output.writeLong(fileSplitterFetch.nEndPos); 1vobfZ-w9  
} HG Pbx$!  
output.close();  X'0A"9  
} Bq'hk<ns[  
catch(IOException e){e.printStackTrace ();} L,R9jMx?_  
catch(Exception e){e.printStackTrace ();} Y yI|^f8C  
} /6>2,S8Ar  
l9n 8v\8,o  
BV<LIrAS  
//读取保存的下载信息(文件指针位置) *G=n${'  
private void read_nPos() wTOB'  
{ sO6+L #!  
try{ %F03cI,  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iK)w3S}k1y  
int nCount = input.readInt(); 1y 6H2  
nStartPos = new long[nCount]; wLW!_D,/R  
nEndPos = new long[nCount];  ,5<-\"{]  
for(int i=0;i<nStartPos.length;i++) Qg3 -%i/@  
{ O9!<L.X,%  
nStartPos = input.readLong(); 55hJRm3  
nEndPos = input.readLong(); ?onZ:s2  
} z]tvy).  
input.close(); +&JF|#FQ`  
} Ff|?<\x0}A  
catch(IOException e){e.printStackTrace ();} ~aBALD0D;  
catch(Exception e){e.printStackTrace ();} sjztT<{Q^-  
} W/fM0=!  
&bTadd%0  
ZQ@^(64  
private void processErrorCode(int nErrorCode) F+9|D  
{ >&p_G0-  
System.err.println("Error Code : " + nErrorCode); ; 5oY)1  
} -Ndd6O[ a5  
?9/%K45  
@aI`ru+a  
//停止文件下载 AM\`v'I*6  
public void siteStop() [S'ngQ"f`  
{ }(ot IqE  
bStop = true; d[jxU/.p;  
for(int i=0;i<nStartPos.length;i++) C#;}U51:t  
fileSplitterFetch.splitterStop(); GN(PH/fO9  
z;1yZ4[G  
_^Rf*G!  
} J/=b1{d"n  
} ;p) gTQa  
//负责部分文件的抓取 ASPfzW2  
**FileSplitterFetch.java 2#ypM9  
*/ Iy\K&)5?  
package NetFox; !%sj-RMvG  
^+!!:J|ra  
jg' 'T1)  
import java.io.*; cy%^P^M  
import java.net.*; .z)&#2E  
-&%#R_RV  
& Z*&&  
public class FileSplitterFetch extends Thread { 3<#4  
"m(HQ5e)*  
nTp?  
String sURL; //File URL R 8?Xz5  
long nStartPos; //File Snippet Start Position rWAJL9M  
long nEndPos; //File Snippet End Position ,,lrF.  
int nThreadID; //Thread's ID V]<J^m8  
boolean bDownOver = false; //Downing is over 7l%O:M(\  
boolean bStop = false; //Stop identical ' !ZFK}  
FileAccessI fileAccessI = null; //File Access interface AI/xOd!a  
?HAWw'QW  
szGp<xv_p  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6xvyhg#B  
{ _.yBX\tf[  
this.sURL = sURL; 8?J\  
this.nStartPos = nStart; Q3'\Vj,S&  
this.nEndPos = nEnd; `pOiv&>  
nThreadID = id; S3A OT  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ="JLUq*]s  
} ldO6W7 G|h  
~;9B\fE`  
H<Ed"-n$I<  
public void run() u#ag|b/C:  
{ oX8e}  
while(nStartPos < nEndPos && !bStop) cEhwv0f!qS  
{ ?1JS*LQ$  
,=.&  
VMe~aUd  
try{ ? L|m:A`  
URL url = new URL(sURL); LSs!U 3"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :?O+EE  
httpConnection.setRequestProperty("User-Agent","NetFox"); @Q 8E)k@  
String sProperty = "bytes="+nStartPos+"-"; [f!sBJ!  
httpConnection.setRequestProperty("RANGE",sProperty); ]SA]{id+  
Utility.log(sProperty); 0V }knR.l  
^0Cr-  
{|9x*I  
InputStream input = httpConnection.getInputStream(); MDM/~Qpj_  
//logResponseHead(httpConnection); Hw-,sze j"  
rd vq(\A  
h%|Jkx!v-t  
byte[] b = new byte[1024]; )#%k/4(Y  
int nRead; WyF1Fw  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TyI"fP  
{ o4^rE<vJ  
nStartPos += fileAccessI.write(b,0,nRead); FZ)_WaqGf  
//if(nThreadID == 1) dj3}Tjt  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y &6vTU  
} *fQ$s  
!yI , ~`Z  
G|*^W;(Z  
Utility.log("Thread " + nThreadID + " is over!"); mR\rK&'6  
bDownOver = true; {9S=:  
//nPos = fileAccessI.write (b,0,nRead); QVA)&k'T,  
} zUF%`CR  
catch(Exception e){e.printStackTrace ();} $[x2L s~  
} ,HO~NqmB4  
} ]@wee08  
|]kcgLqj  
v1*Lf/  
//打印回应的头信息 )u)]#z  
public void logResponseHead(HttpURLConnection con) bKRz=$P?  
{ //9Ro"  
for(int i=1;;i++) ?=}~]A5N  
{ #+I)<a7\  
String header=con.getHeaderFieldKey(i); > 1 {V  
if(header!=null) ~"6/OJA  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TY6 D.ikA  
Utility.log(header+" : "+con.getHeaderField(header)); >G(M&  
else c((^l&  
break; )L fXb9}  
} ~?T*D*  
} kq xX!  
zX *+J"x  
XaOq&7  
public void splitterStop() g b:)t }|  
{ cyu)YxT  
bStop = true; .hd<,\nW  
} s wgn( -  
f-!t31?XK  
j{PuZ^v1  
} & c a-  
?|Y/&/;%I  
K.'II9-{  
/* J}a 8N.S  
**FileAccess.java \@6P A  
*//文件访问(定位,写) I`"B<=zi  
package NetFox; KFd !wZ @e  
import java.io.*; 0`y;[qAG[  
?+EN.P[;3  
Byq4PX%B  
public class FileAccessI implements Serializable{ /4w"akB|P  
pI*/ - !I  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l'h[wwEXm{  
RandomAccessFile oSavedFile; E07g^y"}i  
long nPos; %{'hpT~h  
5T]GyftFV  
'U=D6X%V9m  
public FileAccessI() throws IOException 0{u31#0j  
{ *oR`l32O0z  
this("",0); -UgD  
} :i'jQ<|wZN  
qgTN %%"~  
B1\@ n$  
public FileAccessI(String sName,long nPos) throws IOException 38(Cj~u=3  
{ Sg$14B  
oSavedFile = new RandomAccessFile(sName,"rw"); zQsu~8PX  
this.nPos = nPos; 'J*)o<%  
oSavedFile.seek(nPos); mMLxT3Ci8  
} nFE0y3GD8  
L\p@1N?K  
e> "/Uii  
public synchronized int write(byte[] b,int nStart,int nLen) Nc4e,>$]&  
{ z>_jC+  
int n = -1; 6OeRBD&  
try{ |cZKj|0>  
oSavedFile.write(b,nStart,nLen); [p3)C<;ZC  
n = nLen; "f'pa&oHi  
} jU K0?S>  
catch(IOException e) 40VdT|n$$  
{ 9r@T"$V#c  
e.printStackTrace (); E2f9J{ Ki=  
} ]A*v\Qy  
Iz;hje4JL  
t-#Y6U}b+  
return n; [3":7bB 'E  
} K%TlBK V  
"],amJ  
+bnz%/v  
} wr\d5j  
T?=[6  
CfFNk "0{  
/* |Tz/9t  
**SiteInfoBean.java u#tLY/KA  
*/ 'IrwlS  
package NetFox; 7.O1 ~-  
YE#OAfj~  
}^J&D=J5V  
public class SiteInfoBean { y@!kp*0  
@=jcdn!\M  
#^IEQZgH  
private String sSiteURL; //Site's URL /?b<}am  
private String sFilePath; //Saved File's Path $~,]F  
private String sFileName; //Saved File's Name BS}uv3  
private int nSplitter; //Count of Splited Downloading File a ^+b(&;k  
|qra.\  
oL'  :07_  
public SiteInfoBean() 5p&&EA/  
{//nSplitter的缺省值为5 *GsrG*OM*D  
//default value of nSplitter is 5 n*\AB=|X  
this("","","",5); yQQ[_1$pq  
} |q$br-0+  
/wIev1Z!Y  
% ~%>3  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B8'(3&)My  
{ #mqz*=L3  
sSiteURL= sURL; )F;[  
sFilePath = sPath; fT.5@RR7^  
sFileName = sName; GXaCH))TO  
this.nSplitter = nSpiltter; 9\W~5J<7  
i>bFQ1Rdx  
S\<]|tM:x  
} i3 k ',8  
%^RlE@l9  
1 sCF -r  
public String getSSiteURL() [.P~-6~  
{ Rk fr4  
return sSiteURL; kKVq,41'  
} Py 8o8*H  
vO" $Xw  
c Xcn}gKV  
public void setSSiteURL(String value) ~AuvB4xe~  
{ hIa@JEIt  
sSiteURL = value; 9;;1 "^4/  
} FK!9to>  
Ai iOs?  
EAFKf*K=  
public String getSFilePath() z$p +l]  
{ }/G~"&N[  
return sFilePath; ja2LQe@ Q  
} Pp N+q:(  
NW=j>7  
9a)D8  
public void setSFilePath(String value) (JFa  
{ cd}TDd(H%  
sFilePath = value; J.":oD  
} j^Zp BNL  
K@*m6)  
B!< {s'  
public String getSFileName() N|q:wyS|  
{ |6\ ?"#  
return sFileName; DC*|tHl  
} vE?qF9I{$0  
Y_PCL9G{p  
I}Q3B3Byg  
public void setSFileName(String value) }W<]fK  
{ #eE:hiu<v  
sFileName = value; 4$.UVW\  
} )." zBc#  
 [.z1  
LEVNywk[  
public int getNSplitter() & A9psc(,&  
{ V6wYJ$]  
return nSplitter; ~2A<fL,-  
} WP^%[?S2  
$.kIB+K  
biGaP#"0  
public void setNSplitter(int nCount) )#3 ,y6  
{ f{ S)wE>;  
nSplitter = nCount; v}[KVwse  
} 8qBRO[  
} #_7}O0?c3  
>1s:F5u"  
B5B'H3@  
/* @uY%;%Pa8  
**Utility.java `-ENKr]  
*/ .:RoD?px  
package NetFox; "@` mPe/  
# FaR?L![Y  
QS=n 50T,  
public class Utility { `! m+g0  
V^L;Nw5h  
#C%<g:F8  
public Utility() L1)?5D  
{ ~,':PUkiV  
E C7f  
m U7Ad"  
} T_AZCl4d  
{!oO>t  
//线程睡眠 9zO;sg;3  
public static void sleep(int nSecond) _,F wt  
{  mH?^3T  
try{ =Z-.4\3  
Thread.sleep(nSecond); >+oQxml6nI  
} k )){1O  
catch(Exception e) &Vgjd>  
{ T/ S-}|fhQ  
e.printStackTrace (); :^iR&`2~  
} O gHWmb  
} yMz@-B  
e`}|*^-  
//日志 8CEy#%7]}  
public static void log(String sMsg) cW&OVNj  
{ 5&94VQ$d  
System.err.println(sMsg); yx/:<^"-$  
} l^0 <a<P  
p3^7Hr  
]Dx?HBM"DC  
public static void log(int sMsg) &]z2=\^e  
{ u%*;gu"2  
System.err.println(sMsg); /[EI0 ~P  
} M6?Qw=  
} 9@vY(k k  
,9+@\  
(\R"v^  
/* AH#e>kU^  
**TestMethod.java OH=Ffy F,  
*/ t9P` nfY  
package NetFox; $<33E e:a  
2EE#60  
I|R9@  
public class TestMethod { TD3R/NP  
J::SFu=  
[9+M/O|Vs  
public TestMethod() i!,>3  
{ ///xx/weblogic60b2_win.exe Uw)K [T  
try{ n!tCz<v  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lXz<jt@5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u8[X\f  
SiteFileFetch fileFetch = new SiteFileFetch(bean); }:hdAZ+z  
fileFetch.start(); Pel3e ~?t  
} z-,U(0 .  
catch(Exception e){e.printStackTrace ();} fk",YtS*  
Bq$bxuhV  
X$st{@}ZB  
} wL%>  
v1)jZ.:  
}QC: !e,yG  
public static void main(String[] args) E26ZVFg  
{ ^|gN?:fA}  
new TestMethod(); ="I]D I  
} f 8uVk|a  
} g\jdR_/  
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