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http断点续传简单实现(java)

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/* 7l$ u.[  
**SiteFileFetch.java 49M1^nMvoo  
*/ S<NK!89  
package NetFox; J'sa{/ #  
import java.io.*; De^:9<{jc  
import java.net.*; ,b&h Lht  
O1c:X7lHc  
~v;+-*t  
public class SiteFileFetch extends Thread { zG<<MR/<  
tuIZYp8tIN  
,pI9=e@O/z  
SiteInfoBean siteInfoBean = null; //文件信息Bean ohq Thl  
long[] nStartPos; //开始位置 $l"%o9ICG  
long[] nEndPos; //结束位置 =?0v,;F9|  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 !L9OJ1F  
long nFileLength; //文件长度 s5{=lP  
boolean bFirst = true; //是否第一次取文件 l*z% Jw  
boolean bStop = false; //停止标志 |u?VlRt  
File tmpFile; //文件下载的临时信息 M"z=114  
DataOutputStream output; //输出到文件的输出流 KloX.y)q  
xU;SRB   
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) !}=eXDn;A_  
public SiteFileFetch(SiteInfoBean bean) throws IOException '(K4@[3t  
{ D0J{pAJ  
siteInfoBean = bean; w,1N ;R&  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); iwnGWGcuS  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); b:(+d"S  
if(tmpFile.exists ()) _a&gbSQv  
{ RE!WuLs0"  
bFirst = false; 4~ x>]  
read_nPos(); TOiLv.Dor  
} UP#@gxF  
else C:1(<1K  
{ 'D W|a  
nStartPos = new long[bean.getNSplitter()]; or-k~1D  
nEndPos = new long[bean.getNSplitter()]; ET[5`z  
} +}jzge"  
m{>1# 1;$t  
qkfof{z  
1c,#`\Iikd  
} #19O5  
.#y#u={{l  
t__f=QB/  
public void run() kQI'kL8>  
{ %@QxU-k_  
//获得文件长度 QFTiE1mGH  
//分割文件 iv`G}.Bo  
//实例FileSplitterFetch 0d[O/Q`  
//启动FileSplitterFetch线程 #8jiz+1 _  
//等待子线程返回 I=DVMG|  
try{ t %u0=V  
if(bFirst) L#`X ]E  
{ #>yOp *  
nFileLength = getFileSize(); D[^K0<-Z  
if(nFileLength == -1) i~x]!!  
{ 6$#,$aO  
System.err.println("File Length is not known!"); Kmx4bp4  
} Jk{SlH3'  
else if(nFileLength == -2) Gd!_9S`68  
{ $.C\H,H  
System.err.println("File is not access!"); H@- GYX"4  
} @zGF9O<3,@  
else M8lw; (  
{ f['I4 /o  
for(int i=0;i<nStartPos.length;i++) l&\y]ZV={  
{ WG,Il/  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); .XpuD,^;@  
} Xg.Lo2s  
for(int i=0;i<nEndPos.length-1;i++) W. d',4)  
{ sssw(F  
nEndPos = nStartPos[i+1]; t<Sa ;[+  
} z*HM_u  
nEndPos[nEndPos.length-1] = nFileLength; )4fQ~)  
} (tO4UI5!  
} dr#%~I  
T=NLBJ  
y ;mk]  
//启动子线程 5[g&0  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \<I&utn  
for(int i=0;i<nStartPos.length;i++) /y1+aTiJ  
{ L%[>z'Zp  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ="G2I\  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [<r.M<3  
nStartPos,nEndPos,i); b4:{PD~Mh  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K1YxF  
fileSplitterFetch.start(); jNbVp{%/S}  
} j hRr!  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _G)A$6weU  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;Q3[} ]su  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b1^wK"#  
nEndPos = " + nFileLength); L=54uCv Q  
// fileSplitterFetch[nPos.length-1].start(); m|JA }&A  
o w(9dB&E  
UZsvYy?  
//等待子线程结束 }r18Y6  
//int count = 0; IqlCl>_j  
//是否结束while循环 |FFz $'8)  
boolean breakWhile = false; BN(=LQ2["  
1z|bQ,5  
7Z9'Y?[m  
while(!bStop) yC ?p,Ci,  
{  G>?kskm  
write_nPos(); V~jp  
Utility.sleep(500); C-ORI}o  
breakWhile = true; dU_;2d$  
oFp1QrI3k8  
+hKU]DP2;  
for(int i=0;i<nStartPos.length;i++) l4mRNYv)z  
{ W*iTg%a\k  
if(!fileSplitterFetch.bDownOver) f>xi (0  
{ ;HYEJ3  
breakWhile = false; IAbQgBvUD  
break; ta5_k&3N  
} NHUJ:j@  
} 1mHS -oI9J  
if(breakWhile) +<$nZ=,hsy  
break; S/*\j7cj  
@gqZiFM)  
Rkg)yme!N  
//count++; An}RD73!w  
//if(count>4) C ]B P}MY<  
// siteStop(); DXj>u9*%  
} yQ^,>eh  
QiA}0q3]0  
H9'psv  
System.err.println("文件下载结束!"); &tbAXU5$  
} 6n]jx:CZ,  
catch(Exception e){e.printStackTrace ();} 3O 4,LXdA  
} 9: g]DIL  
ho6hjhS|u  
QSzht$ 8  
//获得文件长度 <!G\%C  
public long getFileSize() gP|-A`y  
{ gT=pO`a  
int nFileLength = -1; )sQ/$gJ  
try{ RIUJX{?  
URL url = new URL(siteInfoBean.getSSiteURL()); myVa5m!7Q  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {d#sZT  
httpConnection.setRequestProperty("User-Agent","NetFox"); I%:?f{\  
4dN <B U  
T)<^S(5 7  
int responseCode=httpConnection.getResponseCode();  96;5  
if(responseCode>=400) :!cK?H$+  
{ A[@koLCL  
processErrorCode(responseCode); fp(zd;BSQ  
return -2; //-2 represent access is error $;(@0UDE  
} ab9ecZ  
%H{;wVjK  
g/68& M  
String sHeader; gREk,4DAv  
s5G`?/  
g - !  
for(int i=1;;i++) *@^@7`W  
{ .>r3ZwrE'  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V= &M\58  
//Utility.log(in.readLine()); _U LzA  
sHeader=httpConnection.getHeaderFieldKey(i); [f { qb\  
if(sHeader!=null) X}]A_G  
{ 2[=3-1c  
if(sHeader.equals("Content-Length")) "~.4z,ha  
{ fUCjC*#1  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S8kzAT  
break; $"( 15U  
} *pD|N  
} $8(QBZq  
else %2b^t*CQ  
break; )l! /7WKY  
} u^MRKLn  
} :_xfi9L~W0  
catch(IOException e){e.printStackTrace ();} 7f k)a  
catch(Exception e){e.printStackTrace ();} mrsmul{  
}pf|GdL  
pl[@U<8aw  
Utility.log(nFileLength); F =*4] O  
31 <0Nw;l  
J,?F+Qji&=  
return nFileLength; LauGT* z!  
} 1MO-60  
2<!IYEyT  
){)-}M  
//保存下载信息(文件指针位置) YL!{oHs4  
private void write_nPos() ' =5B   
{ Id`V`|q  
try{ Nr]Fh  
output = new DataOutputStream(new FileOutputStream(tmpFile)); $kN=45SR  
output.writeInt(nStartPos.length); oj{CNa  
for(int i=0;i<nStartPos.length;i++) \1<|X].jNY  
{ !"yr;t>|Zb  
// output.writeLong(nPos); ia_@fQ  
output.writeLong(fileSplitterFetch.nStartPos); ,W[J@4.  
output.writeLong(fileSplitterFetch.nEndPos); ?B e}{Qqlg  
} aaKf4}  
output.close(); uxDM #  
} A/:_uqm4  
catch(IOException e){e.printStackTrace ();} ^$% Sg//  
catch(Exception e){e.printStackTrace ();} (y6}xOa(  
} :Cx|(+T  
_[E+D0A  
1|w@f&W"  
//读取保存的下载信息(文件指针位置) ORF:~5[YS`  
private void read_nPos() + a nsN~3  
{ -n[(0n3c  
try{ } )L z%Z  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7$g$p&,VX  
int nCount = input.readInt(); ,YvOk|@R  
nStartPos = new long[nCount]; /i27F2NQm  
nEndPos = new long[nCount]; q1eMK'1  
for(int i=0;i<nStartPos.length;i++) J]Z~.f="  
{ T\$i=,_$  
nStartPos = input.readLong(); <},JWV3  
nEndPos = input.readLong(); [mjie1j/<  
} #| ,cy,v4  
input.close(); |LbAW /9a  
} vC@^B)5gb  
catch(IOException e){e.printStackTrace ();} *{+{h;p  
catch(Exception e){e.printStackTrace ();} #O;JV}y  
} E X'PRNB,  
a9p:k ]{  
bFajK;  
private void processErrorCode(int nErrorCode) ILAn2W  
{ qF `6l(  
System.err.println("Error Code : " + nErrorCode); YI7M%B9Lj  
} Mth:V45G|  
ti%RE:*  
_ h#I}uJ~  
//停止文件下载 TvDC4tm-:  
public void siteStop() 3Ji$igL  
{ g6lWc@]F  
bStop = true; AnX<\7bc}  
for(int i=0;i<nStartPos.length;i++) QM 3DB  
fileSplitterFetch.splitterStop(); z#o''  
hchG\ i  
m#8[")a$"  
} vaP`'  
} X|Y(*$?D7  
//负责部分文件的抓取 Ky%lu^  
**FileSplitterFetch.java 9-{=m+|b  
*/ ^s7!F.O C  
package NetFox; ,I5SAd|dX  
wz69Yw7  
3Y2~HuM  
import java.io.*; <C(o0u&/  
import java.net.*; O HpV%8`  
&5R|{',(Y  
'n,V*9  
public class FileSplitterFetch extends Thread { bz#]>RD  
=iKl<CqI$E  
cXqYO|3/M  
String sURL; //File URL 9!uiQ  
long nStartPos; //File Snippet Start Position kq5X<'MM9N  
long nEndPos; //File Snippet End Position P* `*^r3  
int nThreadID; //Thread's ID W +ER'lX  
boolean bDownOver = false; //Downing is over jmk Ou5@  
boolean bStop = false; //Stop identical dV'EiNpf  
FileAccessI fileAccessI = null; //File Access interface *QiQ,~Ep  
rfEWh Vy(}  
-GCo`PR?b  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException / 'qoKof  
{ 9)'f)60^  
this.sURL = sURL; Q7XOO3<):  
this.nStartPos = nStart; wTa u.Bo  
this.nEndPos = nEnd; ]n|Jc_Y  
nThreadID = id; w90YlWS#  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J>}J~[ap\J  
} \/Mx|7<  
^ U mYW  
z.SC^/\o|  
public void run() 7:<w)Al!  
{ + tMf&BZ  
while(nStartPos < nEndPos && !bStop) ?![[la+f  
{ :NF4[c  
,?|$DY+=  
OA[e}Vn  
try{ ] c7X~y  
URL url = new URL(sURL); Mq Ai}z%  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vW=L{8zu  
httpConnection.setRequestProperty("User-Agent","NetFox"); 2Ckx.m&  
String sProperty = "bytes="+nStartPos+"-"; H TOr  
httpConnection.setRequestProperty("RANGE",sProperty); m<-ShRr*b  
Utility.log(sProperty); I} jgz  
3@gsKtA&H4  
Ck Nl;g l  
InputStream input = httpConnection.getInputStream(); }<0N)dpT  
//logResponseHead(httpConnection); Xv-p7$?f  
m|qktLx  
;Nj9,Va(t  
byte[] b = new byte[1024]; aE`d[d SG  
int nRead; c[,h|~K/_?  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6UeYZ g  
{ R{H[< s+n  
nStartPos += fileAccessI.write(b,0,nRead); e(? w h   
//if(nThreadID == 1) O1z]d3x  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'f-r 6'_ZX  
} FzJ7 OE |  
~Ba=nn8Cq  
W}CM;~*L  
Utility.log("Thread " + nThreadID + " is over!"); uX6yhaOp|  
bDownOver = true; x)~i`$  
//nPos = fileAccessI.write (b,0,nRead); {p84fR1P  
} t R|dnC4U  
catch(Exception e){e.printStackTrace ();} a]T:wUYG'  
} lhGJ/By- -  
} v4n< G-  
Vb (b3  
kUf i  
//打印回应的头信息 (aa2uctTn  
public void logResponseHead(HttpURLConnection con) {rUg,y{v  
{ eluN~T:W  
for(int i=1;;i++) @&ZQDi  
{ yWi-ic [n  
String header=con.getHeaderFieldKey(i); DW. w=L|5R  
if(header!=null)  yfZNL?2x  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q<dG}aj  
Utility.log(header+" : "+con.getHeaderField(header)); ?;ok9Y  
else $eYL|?P50h  
break; <e2l@@#oy  
} 1 ~zjsi  
} lT|Gkm<G  
ITn%  
K oJ=0jM#  
public void splitterStop() zw>L0gC  
{ )XN_|zCk  
bStop = true; 4E39]vb  
} :R Iz6Tz  
QrYF Lh  
p{g4`o  
} ??,[-Oi  
}Kp!,  
f+h\RE=BGt  
/* ,CfslhO{j  
**FileAccess.java -]Z7^  
*//文件访问(定位,写) Q/+`9z+c  
package NetFox; Dr3_MWJ+  
import java.io.*; ,vR?iNd:q[  
K~TwyB-h  
e&}W#  
public class FileAccessI implements Serializable{ IfK~~XYG  
Lx0nLJ\  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cS;3,#$  
RandomAccessFile oSavedFile; SVe]2ONd  
long nPos; 9TW[;P2> )  
D=0YLQ*rP  
SMEl'y  
public FileAccessI() throws IOException ]`/>hH>+~9  
{ x b,XI/  
this("",0); k]~o=MLmj  
} } oPO`  
K^u,B3  
V`Cy x^P  
public FileAccessI(String sName,long nPos) throws IOException tbFAVGcAM  
{ iW5cEI%tb  
oSavedFile = new RandomAccessFile(sName,"rw"); sQJ\{'g  
this.nPos = nPos; ]r Uj<[O  
oSavedFile.seek(nPos); YOl$sgg}  
} 0:$ }~T9T  
t'n@yX_  
+Nt4R:N  
public synchronized int write(byte[] b,int nStart,int nLen) w% %q/![uy  
{ `6Bx8CZ'I  
int n = -1; x4MmBVqp  
try{ 5h5izA'0'  
oSavedFile.write(b,nStart,nLen); v e&d"8+]  
n = nLen; 7>N~l  
} |P >"a`  
catch(IOException e) ,md_eGF  
{ fiGTI}=P  
e.printStackTrace (); UA>=# $  
} u]yy%@U1  
G4* LO  
m\&|#yq  
return n; a-{|/ n%  
} ingG  
h `Lr5)B'  
S!(3-{nC  
} n' ~ ==2  
7he73  
1m*)MZ)  
/* F.[%0b E  
**SiteInfoBean.java lL D#|T3  
*/ \V? .^/  
package NetFox; Q:-T' xk@  
TnF~'RZYb  
)DgXsT  
public class SiteInfoBean { 1 G>Ud6(3<  
%'Cj~An  
nu0pzq\6  
private String sSiteURL; //Site's URL G+zhL6]F  
private String sFilePath; //Saved File's Path )bUnk +_  
private String sFileName; //Saved File's Name orGMzC2  
private int nSplitter; //Count of Splited Downloading File /K:r4Kw  
}Fe6L;^;  
@{Rb]d?&F?  
public SiteInfoBean() ZQ`8RF *v  
{//nSplitter的缺省值为5 -xn-A f!v  
//default value of nSplitter is 5 =:H-9  
this("","","",5); b>ai"!  
} 4agW<c#  
dY 8 H2;  
%U\,IO`g  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lw@Yn>eza  
{ 3&hR#;,"X  
sSiteURL= sURL; zp}7p~#k^  
sFilePath = sPath; p<5]QV7st  
sFileName = sName; Q((&Q?Vi  
this.nSplitter = nSpiltter; %*D=ni#(sT  
[D"6&  
z|#*c5Y9w  
} ?P kJG ,~  
k2}DBVu1  
G6G Bqp6|  
public String getSSiteURL() %e iV^>  
{ @ {/)k%U  
return sSiteURL; "Z.6@ c7  
} p{Lrv%-j  
)z[C=  
ha :l-<a  
public void setSSiteURL(String value) =pL$*`]?  
{ fn}E1w  
sSiteURL = value; ~+Wx\:TT  
} vjEDd`jYZ  
K~L&Z?~|E  
Z RVt2  
public String getSFilePath() NI?O  
{ f_~T  
return sFilePath; ;hT3N UCA  
} )D8op;Fn  
UmR)L!QT8  
8eXe b|?J  
public void setSFilePath(String value) XGa8tI[:X  
{ l.}PxZ  
sFilePath = value; "~4V(  
} 5rsz2;#p  
ufXWK3~\  
"Bd-h|J  
public String getSFileName() 9g6$"',H  
{ [ V.67_~  
return sFileName; OyO<A3  
} GfONm6A  
Ao K9=F}  
,DFN:uf=l  
public void setSFileName(String value) J!C \R5\  
{ @)pC3Vi^  
sFileName = value; ,Fn;*  
} - Jaee,P  
M5I`i{Gw  
'\bokwsP  
public int getNSplitter() mERkC,$  
{ Cy-p1s  
return nSplitter; ZF>:m>  
} U$y 9f  
G&oD;NY@/  
m` 1dB%;?  
public void setNSplitter(int nCount) z^9oaoTl  
{  [N,+mX  
nSplitter = nCount; 7$*E0  
} bxa>:71  
} :<g0Ho?e  
_7!ZnJrR  
P'KA-4!  
/* h8/tKyr8(  
**Utility.java 6u_i >z  
*/ ^q-%#  
package NetFox; DOWWG!mx  
 q0ktABB  
gS FZ>v*6  
public class Utility { 8F[ ];LF>  
Y-it3q'Z  
DuC#tDP  
public Utility() K~:SLCv E%  
{ 4)iP%%JH  
%pVsafV  
"}()/  
} qc(e3x  
)>~ jjR  
//线程睡眠 3EYEd39E  
public static void sleep(int nSecond) z</C)ObL  
{ ?NA $<0  
try{ P%R!\i  
Thread.sleep(nSecond);  ?s,oH  
} @|A!?}  
catch(Exception e) Sh#N5kgD  
{ 1uw1(iL+  
e.printStackTrace (); $}vk+.!*1  
} i$kB6B#==  
} WN]k+0#  
6%V:Z  
//日志 0(i3RPIj\  
public static void log(String sMsg) _i>_Sn1"  
{ l~$)>?ZD  
System.err.println(sMsg); ;bwBd:Y  
} nc1~5eo  
<VZ43I  
}[leUYi`  
public static void log(int sMsg) {XU!p: x  
{ l2;$qNAo  
System.err.println(sMsg); b@J"b(  
} ((gI OTV  
} T.cTL.}  
FWu:5fBZY  
Sfe[z=7S  
/* ;MeY@* "{  
**TestMethod.java g#(+:^3'  
*/ '/`O*KD]  
package NetFox; @vq)Y2)r\  
T;DKDg a  
XW aa`q  
public class TestMethod { YWU@e[  
UG\2wH_  
@ 95p[  
public TestMethod() J4eU6W+{  
{ ///xx/weblogic60b2_win.exe KKpM=MZ  
try{ *  1}dk`-  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NrS+N;i  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7=G6ao7  
SiteFileFetch fileFetch = new SiteFileFetch(bean); |6^a[x3/U  
fileFetch.start(); Xr^ 5Th\  
} rhLhFN{h  
catch(Exception e){e.printStackTrace ();} @(L}:]{@  
25Ee+&&%  
L:C/PnIV  
} d"5_x]Z;  
 IZrcn  
Ch{6=k bK  
public static void main(String[] args) Lu^uY7 ?}  
{ H, 3Bf  
new TestMethod(); X.{xH D&_  
} 2XL^A[?   
} z:S:[X 0  
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