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http断点续传简单实现(java)

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/* h/oRWl0r  
**SiteFileFetch.java ~6{iQZa1Y  
*/ 8;PS>9<  
package NetFox; /q| r!+  
import java.io.*; G5WQTMzf&  
import java.net.*; ]MD,{T9l\>  
EPEWyGw  
5Zf^cou  
public class SiteFileFetch extends Thread { G)|Xj70  
Wd`*<+t]  
Borr  
SiteInfoBean siteInfoBean = null; //文件信息Bean vHJOpQmt~  
long[] nStartPos; //开始位置 LNz  
long[] nEndPos; //结束位置 @%lkRU)  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 fe!eZiE  
long nFileLength; //文件长度 kM6i{{Q  
boolean bFirst = true; //是否第一次取文件 'FNnFm  
boolean bStop = false; //停止标志 2xLEB&  
File tmpFile; //文件下载的临时信息 (rmOv\hG9V  
DataOutputStream output; //输出到文件的输出流 GB%kxtGD;\  
18^#:=Z  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) oACbZ#/@n  
public SiteFileFetch(SiteInfoBean bean) throws IOException t1JU_P  
{ HNJR&U t  
siteInfoBean = bean; p< Y-b,&  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); {EfA#{x  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); /0Jf/-}ovn  
if(tmpFile.exists ()) HLe/|x\@<  
{ zG0]!A  
bFirst = false; Y#,&Tu  
read_nPos(); T,a71"c  
} 6"Ze%:AZZ  
else 0OXl`V`w  
{ YpOcLxFL  
nStartPos = new long[bean.getNSplitter()]; oF0DprP@  
nEndPos = new long[bean.getNSplitter()]; Y\,aJL$  
} vfd<qdi3p(  
`q9n`h1  
XS}-@5TI  
wBWqibY|  
} 4s e6+oJe  
?8w5tfN6t  
_1?nLx7n  
public void run() Dm@h'*  
{ ;^TSla+t+  
//获得文件长度 GlHP`&;UH  
//分割文件 ^e]O-,UBk  
//实例FileSplitterFetch y6dQ4Whv&  
//启动FileSplitterFetch线程 {Rdh4ZKh  
//等待子线程返回  0ij YE  
try{ J-|&[-Z  
if(bFirst) J(G-c5&=  
{ R XCjYzt  
nFileLength = getFileSize(); =P9Tc"2PN  
if(nFileLength == -1) ?y]R /?  
{ xHCdtloi?I  
System.err.println("File Length is not known!"); ]v/pMg#-  
} qSDn0^y  
else if(nFileLength == -2) C hQ] d  
{ ~ _hA{$  
System.err.println("File is not access!"); dVPY07P  
} S n<X   
else (wFoI}s  
{ -e_|^T"  
for(int i=0;i<nStartPos.length;i++) `g_r<EY8/  
{ Kx?.g#>U;  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Y_}_)nE@m  
} =:Yrb2gP_\  
for(int i=0;i<nEndPos.length-1;i++) !>"fDz<w`  
{ lUaJC'~p  
nEndPos = nStartPos[i+1]; HOx+umjxW  
} v8WT?%  
nEndPos[nEndPos.length-1] = nFileLength; bsm/y+R  
} ]bAVOKm-  
} F @<h:VVP  
Sgr. V)  
mr2Mu  
//启动子线程 H|0-Al.{  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 73 4t  
for(int i=0;i<nStartPos.length;i++) ,>01Cs=t8  
{ Y]=k"]:%  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +?W4ac1  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q`'"+`h  
nStartPos,nEndPos,i); n!.=05OtX  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qco uZO  
fileSplitterFetch.start(); (/0dtJ  
} xFekSH7[F  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \>>P%EU,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e/_QS}OA  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FrUqfTi+W  
nEndPos = " + nFileLength); ZPY&q&R  
// fileSplitterFetch[nPos.length-1].start(); 6:L2oW 6}{  
`a:3S@n(}  
K@JaN/OM  
//等待子线程结束 AAs&P+;  
//int count = 0; S*>T%#F6Uo  
//是否结束while循环 jV9oTH-  
boolean breakWhile = false; SB08-G2  
 sa&`CEa  
O) TS$  
while(!bStop) !Vg=l[  
{ K3<A<&W_-  
write_nPos(); ZjMnGRP  
Utility.sleep(500); 6D[]Jf,9  
breakWhile = true; w3"L5;oH  
_yUYEq<`  
:s&dn%5N"  
for(int i=0;i<nStartPos.length;i++) <YtjE!2  
{ f>$RR_  
if(!fileSplitterFetch.bDownOver) y3o3G  
{ <&3aP}  
breakWhile = false; jDqG9]  
break; Ef?hkq7X<  
} hdi0YL  
} x{8h3.ZQ,  
if(breakWhile) r#2Fk &Z9  
break; UKZ )Boo  
.4U*.Rf  
mNacLkh[  
//count++; j)Ak:l%a  
//if(count>4) ;3wO1'=  
// siteStop(); nw% 9Qw  
} uSRhIKy  
qljsoDG  
KK #E qJ  
System.err.println("文件下载结束!"); Osm))Ua(  
} 1%*\*z  
catch(Exception e){e.printStackTrace ();} =EMB~i  
} __Ksn^I   
T]Ai{@i  
D>7J[ Yxg-  
//获得文件长度 2nC,1%kxhq  
public long getFileSize() GVJ||0D  
{ mICEJ\`x  
int nFileLength = -1; H\a"=&M  
try{ *9$SFe|&n:  
URL url = new URL(siteInfoBean.getSSiteURL()); M /v@C*c  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~=iH*AQR  
httpConnection.setRequestProperty("User-Agent","NetFox"); z)U7  
)MK $E,W  
:o{,F7(P  
int responseCode=httpConnection.getResponseCode(); oPr`SYB  
if(responseCode>=400) ;*<R~HJt  
{ 1S!}su,uH  
processErrorCode(responseCode); tkcs6uy  
return -2; //-2 represent access is error ?.%dQ0  
} RPgz"-  
+llb{~ZN  
CN:T$ f|)  
String sHeader; IF0!@f  
NT.#U?9c  
Z;81 "   
for(int i=1;;i++) `3i>e<m~  
{ MkoK(m{7  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'WE"$1  
//Utility.log(in.readLine()); 2{63:f1c`'  
sHeader=httpConnection.getHeaderFieldKey(i); Rh|9F yN  
if(sHeader!=null) j\~,Gtn>Z  
{ -'d:~:1f  
if(sHeader.equals("Content-Length")) ?l?l<`sTO  
{ EUuSN| a  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,7Hyrx`  
break; mLZ1u\ 7W  
} k Alx m{  
} -i2rcH  
else Ge-Bk)6  
break; )w M%Ul<s  
} mXp#6'a  
} +|obU9M  
catch(IOException e){e.printStackTrace ();} 3PU_STSix  
catch(Exception e){e.printStackTrace ();} EwN{|34C  
8(\}\4G_  
2@6@|jRG  
Utility.log(nFileLength); {+WY,%e  
#\lvzMjCC  
H)D|lt5xy  
return nFileLength; fF0i^E<  
} Tt)z[^)%  
{V QGfN  
b+|Jw\k  
//保存下载信息(文件指针位置) r9_ ON|  
private void write_nPos() M.mn9kw`  
{ Fk/I (Q  
try{ vw2E$ya  
output = new DataOutputStream(new FileOutputStream(tmpFile)); hXjZ>n``  
output.writeInt(nStartPos.length); k9rws  
for(int i=0;i<nStartPos.length;i++) <C'_:&M  
{ hYkk r&  
// output.writeLong(nPos); Bgm8IK)6  
output.writeLong(fileSplitterFetch.nStartPos); JfN5#+_i  
output.writeLong(fileSplitterFetch.nEndPos); QLO;D)fC  
} =){ G  
output.close(); R}0gIp=  
} 1WMZ$vsQUb  
catch(IOException e){e.printStackTrace ();} _ f%s]  
catch(Exception e){e.printStackTrace ();} -`k>(\Q< d  
} ;pW8a?  
8{G!OBxc\.  
cRnDAn#42  
//读取保存的下载信息(文件指针位置) 4@-tT;$  
private void read_nPos() Jj \ nye+  
{ OOSf<I*>  
try{ _C/|<Ot:  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7@;*e=v  
int nCount = input.readInt(); ['}|#3*w  
nStartPos = new long[nCount]; zas&gsl-;  
nEndPos = new long[nCount]; %[p*6&V  
for(int i=0;i<nStartPos.length;i++) A`3KE9ED  
{ g9pKoi|\E  
nStartPos = input.readLong(); 6LDZ|K@  
nEndPos = input.readLong(); JU>~[yAP  
} _s^tL2Pc  
input.close(); $#h U_vr  
} plWNuEW  
catch(IOException e){e.printStackTrace ();} #EzhtuHxn  
catch(Exception e){e.printStackTrace ();} $vXY"-k  
} -t4:%-wv  
FFw(`[A_  
e#;43=/Ia  
private void processErrorCode(int nErrorCode) ]eGa_Ld  
{ ` 7iA?;  
System.err.println("Error Code : " + nErrorCode); ]"T157F  
} QPf\lN/$4d  
%0-oZL  
@o0HDS  
//停止文件下载 #a}w&O";  
public void siteStop() lu{ *]!  
{ Gky*EY  
bStop = true; R1LirZlzJ  
for(int i=0;i<nStartPos.length;i++) QIkFX.^  
fileSplitterFetch.splitterStop(); jo"nK,r  
@sn:%/x_  
ZvF#J_%gE5  
} ~},H+A!?  
} _|C3\x1c  
//负责部分文件的抓取 2@a'n@-  
**FileSplitterFetch.java ELwXp|L  
*/ 6Mc&=}bV  
package NetFox; /1LN\Eu  
M#^q <K %  
zRjbEL  
import java.io.*; = cxO@Fu  
import java.net.*; MlWKfe<  
_W(xO |,M  
'Q E8  
public class FileSplitterFetch extends Thread { Q I";[  
co\?SgE35  
\xS X'/G  
String sURL; //File URL `S((F|Ty=;  
long nStartPos; //File Snippet Start Position n/;{-  
long nEndPos; //File Snippet End Position zKP[]S-  
int nThreadID; //Thread's ID ]xvhUv!G  
boolean bDownOver = false; //Downing is over s&ox%L4  
boolean bStop = false; //Stop identical On);SN'  
FileAccessI fileAccessI = null; //File Access interface ? /!Fv/  
'~ b  
DH\Ox>b=  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {@KLN<  
{ LeN }Q  
this.sURL = sURL; *P *.'XM  
this.nStartPos = nStart; A(&\wd  
this.nEndPos = nEnd; a)2l9  
nThreadID = id; <tTNtBb  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @GAj%MK$  
} iOa<=  
$!G|+OuTR  
{0j,U\ kb  
public void run() }%wP^6G*x\  
{ rIPg,4y*S!  
while(nStartPos < nEndPos && !bStop) \|X 1  
{ fX9b1x  
1<x5{/CZ  
;woK96"{t  
try{ v0WB.`rO  
URL url = new URL(sURL); ?z)2\D  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +q2\3REzx  
httpConnection.setRequestProperty("User-Agent","NetFox"); uu4! e{K  
String sProperty = "bytes="+nStartPos+"-"; 2pHR$GZ2  
httpConnection.setRequestProperty("RANGE",sProperty); Flpl,|n a  
Utility.log(sProperty); ? }^ y6  
zk70D_}L  
XH0{|#hwN  
InputStream input = httpConnection.getInputStream(); ++w{)Io Z  
//logResponseHead(httpConnection); zhE4:g9v  
\zVp8MMf  
M&zB&Ia"'  
byte[] b = new byte[1024]; L9hL@  
int nRead; unYPvrd  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sk5=$My  
{ , -d2wzhW  
nStartPos += fileAccessI.write(b,0,nRead); 8fvKVS  
//if(nThreadID == 1) 78T;b7!-C  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d?U,}tv  
} 5-a^Frmg#"  
QncjSaEE  
E]{0lG`l  
Utility.log("Thread " + nThreadID + " is over!"); Yo5ged]i  
bDownOver = true; LUx'Dm"  
//nPos = fileAccessI.write (b,0,nRead); #I ,c'Vj  
} L(y~ ,Kc  
catch(Exception e){e.printStackTrace ();} pOy(XUV9O  
} z,qNuv"W  
} U GOe(JB  
|Qpo[E }a  
F":dS-u&L  
//打印回应的头信息 K=sk1<>)m  
public void logResponseHead(HttpURLConnection con) _n*gj-  
{ >hnhV6ss  
for(int i=1;;i++) 6jal5<H  
{ ) \cnz  
String header=con.getHeaderFieldKey(i); ^*NOG\BK@  
if(header!=null) Sr6iQxE  
//responseHeaders.put(header,httpConnection.getHeaderField(header));  Mv%B#J  
Utility.log(header+" : "+con.getHeaderField(header)); 0,LUi*10  
else &6Wim<*  
break; H'2o84$  
} \bSakh71  
} 78mJ3/?rC  
S@L%X<Vm  
Q|Pm8{8  
public void splitterStop() ^^Q> AfTR.  
{ k"`^vV[{F  
bStop = true; ]G~u8HPH!m  
} G#^6H]`[J:  
KC\W6|NtGj  
\ ]h$8JwV  
} P_N},Xry  
:rmi8!o  
6:TA8w|  
/* s[*I210  
**FileAccess.java `? f sU  
*//文件访问(定位,写) PPtJ/ }\  
package NetFox; KU0;}GSNX}  
import java.io.*; VS<w:{*  
6;\Tps;A  
iEBxBsz_  
public class FileAccessI implements Serializable{ =~ j S  
hniTMO  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Su`] ku'  
RandomAccessFile oSavedFile; |fWR[\NU  
long nPos; cT^x^%  
}l@7t&T|  
*7/MeE6)i  
public FileAccessI() throws IOException Il s^t  
{ ZP7wS  
this("",0); 1\Vp[^#Vx  
} Yh;A  
.*w3ryQ  
Zv1/J}+  
public FileAccessI(String sName,long nPos) throws IOException BO=j*.YKy  
{ m[*y9A1  
oSavedFile = new RandomAccessFile(sName,"rw"); UXV>#U?  
this.nPos = nPos; cX-) ]D  
oSavedFile.seek(nPos); /SYzo4(  
} [;i3o?\_I  
,G(bwE9~  
K"ytE2:3  
public synchronized int write(byte[] b,int nStart,int nLen) e/u (Re  
{ r)t-_p37  
int n = -1; Xc@%_6  
try{ 4EEXt<c.  
oSavedFile.write(b,nStart,nLen); 7tz #R :  
n = nLen; _S#3!Wx  
} &l1CE1 9<  
catch(IOException e) |-k~Fa  
{ EPwM+#|e-  
e.printStackTrace (); s av  
} aruT eJF  
0--0+?  
FZhjI 8+,~  
return n; !_UBw7Zm  
} <</ Le%  
qc`UDD5  
3P2L phW  
} g JMv  
f0lK ,U@P  
ns[Q %_  
/* cn!Y7LVr  
**SiteInfoBean.java k7Z1Y!n7  
*/ q\6ZmKGnT  
package NetFox; Lv?e[GA  
)OcG$H NK  
*l4`2eqZ  
public class SiteInfoBean { % 2lcc"'  
('.r_F  
rN^P//  
private String sSiteURL; //Site's URL 7Cj6Kw5k  
private String sFilePath; //Saved File's Path _-g?6q  
private String sFileName; //Saved File's Name @=1kr ^i  
private int nSplitter; //Count of Splited Downloading File 9gokTFoN  
%phv<AW  
Nt'u;0  
public SiteInfoBean() q+-Bl  
{//nSplitter的缺省值为5 Syj7K*,%bZ  
//default value of nSplitter is 5 -%x9^oQwY  
this("","","",5); |CFTOe\ q  
}  =:-x;  
(*2kM|  
bfjtNF*^  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *z A1NH5  
{ S7 Tem:/  
sSiteURL= sURL; 2r=A'  
sFilePath = sPath; v'zf*]9  
sFileName = sName; !EQMTF=(  
this.nSplitter = nSpiltter; v(tr:[V  
<+c6CM$#}V  
7&z`N^dz{  
} B}y-zj; T  
9>"To  
;eeu 9_$  
public String getSSiteURL() f#9\&-h e0  
{ m^)h/s0A  
return sSiteURL; lE?F Wt  
} (7g1eEK%  
c);(+b  
7Q9zEd" d  
public void setSSiteURL(String value) Ll L8Q  
{ ` cgS yRD]  
sSiteURL = value; i`1QR@11  
} A[6$'IJ  
CdRgI^5  
lU<n Wf  
public String getSFilePath() `n!<h,S'2  
{ #Mz N7  
return sFilePath; "K8<X  
} E}$K&<J'-  
-l!;PV S|  
[=Yfdh M8S  
public void setSFilePath(String value) kEQ${F{  
{ Wh)QCp0|n  
sFilePath = value; X>#!s Lt  
} 7QlA/iKqK  
5!PU+9Kh  
F*_mHYa;  
public String getSFileName() H[{ch t h  
{ \5%T'S@5  
return sFileName; 0r+%5}|-K  
} l%^'K%'b  
:hp=>^$Y  
/L1qdkG  
public void setSFileName(String value) WBA0! g98  
{ F:CqB|  
sFileName = value; dB`YvKr#  
} P==rY5+s`  
;,y9  
46dh@&U  
public int getNSplitter() EnrRnVB  
{ '~E&^K5hr  
return nSplitter; 5UwaBPj4  
} q lL6wzq,  
Iky'x[p,D  
,!f*OWnZ  
public void setNSplitter(int nCount) >4.{|0%ut  
{ he/UvMu  
nSplitter = nCount; ^AUmIyf_  
} [Uezi1I  
} PF1m :Iz`d  
zX!zG<<K  
A}b<Lg  
/* otXB:a  
**Utility.java P(W7,GD,k  
*/ /R< Q~G|\  
package NetFox; xOjCF&W  
=J,aBp  
cvbv\G'aT  
public class Utility { -, ~n|ceI  
(d[)U<  
j0k"iv  
public Utility() AR?J[e  
{ Nvs8t%  
"~4ULl< i'  
&Q^M[X  
} `n7z+  
\HDRr*KO  
//线程睡眠 Y>+\:O  
public static void sleep(int nSecond) 6P' m0  
{ <3QE3;4  
try{ G1Cn[F;e  
Thread.sleep(nSecond); }0T1* .Cz  
} f4zd(J  
catch(Exception e) !9i,V{$c`"  
{ :<s)QD  
e.printStackTrace (); iuq-M?1  
} GP uAIoBo  
} i`Es7 }  
}`yIO"{8n  
//日志 :JqH.Sqk  
public static void log(String sMsg) Cl]E rg  
{ ~?dPF;.6_  
System.err.println(sMsg); im_W0tGvF  
} S >uzW #  
9q;\;-  
#zXkg[J6d  
public static void log(int sMsg) vcAs!ls+  
{ 5-}4jwk  
System.err.println(sMsg); Bya!pzbpr  
} fAfsKO*  
} C}+w<  
5>7ECe*  
UGEC_  
/* R{3f5**0  
**TestMethod.java jGEUl=W  
*/ j3~:\H  
package NetFox; >(u=/pp=:  
Fy<dk}@  
$CO^dFf  
public class TestMethod { "-vm=d~\  
}}Eko7'^  
J(S.iTD  
public TestMethod() CJ&0<Z}{m  
{ ///xx/weblogic60b2_win.exe l.lXto.6)  
try{ V$-IRdb  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); APuG8 <R,  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B[Uvj~g  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0W9,uC2:N  
fileFetch.start(); ;|b D@%@  
} xF5q=%n  
catch(Exception e){e.printStackTrace ();} R1X9  
Jk|c!,!  
`Bnp/9q5  
} \A _g  
+is;$ 1rq  
N>7INK  
public static void main(String[] args) `RfhxzI  
{ cgm]{[f  
new TestMethod(); ]~)FMWQz-  
} _odP:  
} /_?Ly$>'  
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