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http断点续传简单实现(java)

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/* Zt3)]sB  
**SiteFileFetch.java EMc;^ d  
*/ A|@_}h"WG  
package NetFox; pm6>_Kz  
import java.io.*; D91e\|]  
import java.net.*; ]7Z{ 8)T  
o,P.& m{?  
STJJU]H  
public class SiteFileFetch extends Thread { A?@@*$&  
BY]i;GVq  
U. @*`Fg  
SiteInfoBean siteInfoBean = null; //文件信息Bean U5 r7j  
long[] nStartPos; //开始位置 }`NU@O#  
long[] nEndPos; //结束位置 "hQ_sgz[Z  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 i:l<C  
long nFileLength; //文件长度 kMsnW}Nu  
boolean bFirst = true; //是否第一次取文件 h48SItY  
boolean bStop = false; //停止标志 h/,${,}J  
File tmpFile; //文件下载的临时信息 .&x}NYX4  
DataOutputStream output; //输出到文件的输出流 2mq$H_  
.T*GN|@$!  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) E[^ {w  
public SiteFileFetch(SiteInfoBean bean) throws IOException 2>l,no39t+  
{ 8L1ohj  
siteInfoBean = bean; VG>vn`x>a  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); :(_+7N[KA  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 2z@\R@F  
if(tmpFile.exists ()) ^`D=GF^tX  
{ 42\-~]  
bFirst = false; $:of=WTY(  
read_nPos(); E~kG2x{a  
} ZY56\qcY  
else c   c  
{ M+!x}$ &v  
nStartPos = new long[bean.getNSplitter()]; SZ_V^UX_  
nEndPos = new long[bean.getNSplitter()]; BJS-Jy$-  
} ;2m<CSv!D  
9TAj) {U%'  
Rl6\#C*  
[+Y{%U  
} _qWliw:0#  
+B|7p9qy  
=@)d5^<5F  
public void run() ayBRWT0  
{ 5#E |R  
//获得文件长度 b5:op@V  
//分割文件 } 17.~  
//实例FileSplitterFetch gf+d!c(/  
//启动FileSplitterFetch线程 [/_+>M  
//等待子线程返回 ;<Km 3  
try{ jn.C|9/mj  
if(bFirst) LG]3hz9^9  
{ 9,]5v +  
nFileLength = getFileSize(); Yif*"oO  
if(nFileLength == -1) wLV~F[:  
{ 6/ `.(fL1  
System.err.println("File Length is not known!"); cubUq5  
} g-vg6@6  
else if(nFileLength == -2) jw ,izxia  
{ #?B%Ja% ;W  
System.err.println("File is not access!"); A-ZmG7xk  
} Pj?Dmk~   
else CCDDK L]N:  
{ |3? 8)z\n  
for(int i=0;i<nStartPos.length;i++) :"o o>  
{ l?*r5[O>n  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); tD$lNh^  
} ~svO*o Wa  
for(int i=0;i<nEndPos.length-1;i++) smQVWs>  
{ s:y ^_W)d  
nEndPos = nStartPos[i+1]; V84*0&qOW  
} 4F MAz^  
nEndPos[nEndPos.length-1] = nFileLength; 3_5XHOdE  
} ]=F8p2w?  
} A 699FQ  
x6'^4y])  
T{vR,  
//启动子线程 D';eTy Y  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cyd~2\Kv~  
for(int i=0;i<nStartPos.length;i++) PKq-@F%X  
{ &GWkq>  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f*xpE`&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z%gx%$  
nStartPos,nEndPos,i); xU9@$am  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;9uRO*H?T  
fileSplitterFetch.start(); sNU}n<J-  
} F:37MUQi  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;Pb8YvG1$  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \.s`n2.w  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 84&XW  
nEndPos = " + nFileLength); 8)0 L2KL'  
// fileSplitterFetch[nPos.length-1].start(); G { mC7@  
$GF]/;\m  
] y1fM0  
//等待子线程结束 `Xo 4q3  
//int count = 0; vH?9\3  
//是否结束while循环 RB3 zHk%  
boolean breakWhile = false; pvXcLR)L+3  
5^)_B;.f  
"<l<& qp  
while(!bStop) B/eaqJ  
{ )fh0&Y; R  
write_nPos(); E,*&BDW  
Utility.sleep(500); LAZVW</  
breakWhile = true; IjZ@U%g@;  
PJ 9%/Nrh  
#o[\Dwu  
for(int i=0;i<nStartPos.length;i++) >#N[GrJAE  
{ ^b53}f8H  
if(!fileSplitterFetch.bDownOver) y @apJ;_R-  
{ p#H]\ P'  
breakWhile = false; VO`"<  
break; ` Q9+k<  
} 5()Fvae{k  
} d\Jji 6W  
if(breakWhile) |f NMs  
break; aR:<<IF\  
8B@J Fpg^  
lfy7w|  
//count++; ndOfbu;mf  
//if(count>4) \p6 }  
// siteStop(); 2a[9h #  
} .s};F/(diD  
xv0M  
#AncOo  
System.err.println("文件下载结束!"); oCJbkt=  
} Fp:3#Bh  
catch(Exception e){e.printStackTrace ();} +"L$ed(=nJ  
} *ro.mQ_  
c)3O/`  
.Z5[_'T  
//获得文件长度 5<N~3 1z  
public long getFileSize() fq Y1ggL  
{ NW De-<fQ  
int nFileLength = -1; eU~?p|Np  
try{ t F/nah  
URL url = new URL(siteInfoBean.getSSiteURL()); e\~l!f'z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,o)4p\nV  
httpConnection.setRequestProperty("User-Agent","NetFox"); U_*3>Q  
6z]`7`G   
#HDesen  
int responseCode=httpConnection.getResponseCode(); qC.i6IL  
if(responseCode>=400) 6UI>GQ  
{ %Qd3BZ  
processErrorCode(responseCode); qT 0_L  
return -2; //-2 represent access is error uRGB/ju^E  
} ._ih$=   
X X&K=<,Ja  
HPTHF  
String sHeader; xSOoIsL[  
p5`ZyD ]+  
Yhk6Uog{4  
for(int i=1;;i++) D1! {S7  
{ 4ac1m,Jlt  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z'e1"Y.  
//Utility.log(in.readLine()); ] ?9t-  
sHeader=httpConnection.getHeaderFieldKey(i); r_=p,#}#  
if(sHeader!=null) QqjTLuN  
{ <THUsY`3P&  
if(sHeader.equals("Content-Length")) R ^^ 1/%  
{ xBt<Yt"  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b_l.QKk  
break; &*ZC0V3  
} HIrEv  
} FSVS4mtiX\  
else v0u\xX[H;  
break; >eu `!8  
} tPzM7 n|  
} .&L^J&V  
catch(IOException e){e.printStackTrace ();} |zb`&tv}  
catch(Exception e){e.printStackTrace ();} fX""xT NPi  
{ $X X  
*<?XTs<  
Utility.log(nFileLength); *seu&  
sD.6"w7}  
+RdI;QmM  
return nFileLength; 4%%B0[Wo_O  
} (}6wAfGo  
b%<164i  
G u6[{u  
//保存下载信息(文件指针位置) o\:$V   
private void write_nPos() n~9 i^  
{ (UXv,_"nU  
try{ *WD;C0?z  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~DK F%}E  
output.writeInt(nStartPos.length); N JXa_&_  
for(int i=0;i<nStartPos.length;i++)  JUmw$u  
{ QZ?O;K1|y  
// output.writeLong(nPos); S\}?zlV  
output.writeLong(fileSplitterFetch.nStartPos); 9N<*S'Z  
output.writeLong(fileSplitterFetch.nEndPos); +tPx0>p;  
} )K8P+zn~  
output.close(); tx gvVQ  
} _F3KFQ4,S-  
catch(IOException e){e.printStackTrace ();} r+SEw ;  
catch(Exception e){e.printStackTrace ();} a4Ls^  
} u mqLKf=x!  
>7"$}5d  
Q%+ }  
//读取保存的下载信息(文件指针位置) e21E_exM0  
private void read_nPos() ~:2&/MOP?  
{ !-F^VGD(8  
try{ +SO2M|ru&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h=!M6yap<  
int nCount = input.readInt(); <>SR4  
nStartPos = new long[nCount]; |)m*EME  
nEndPos = new long[nCount]; m*\B2\2gJ  
for(int i=0;i<nStartPos.length;i++) \I'f3  
{ >0kmRVd  
nStartPos = input.readLong(); ]jZiW1C*a  
nEndPos = input.readLong();  Y>xi|TWN  
} MV% :ES?  
input.close(); iTj"lA  
} y;zt_O/  
catch(IOException e){e.printStackTrace ();} NG!>7$@RV  
catch(Exception e){e.printStackTrace ();} hTlnw[I  
} 8f /T!5  
^fFtI?.6jI  
:D<:N*9i  
private void processErrorCode(int nErrorCode) x:!C(Ep)  
{ (~q#\  
System.err.println("Error Code : " + nErrorCode); z0\;m{TH  
} x>U1t!'  
JR H f.?  
`Ev A\f  
//停止文件下载 fO[Rf_  
public void siteStop() 5%2ef{T[  
{ %KbBH:z05  
bStop = true; $ /}:P  
for(int i=0;i<nStartPos.length;i++) 3*CzXK>`M&  
fileSplitterFetch.splitterStop(); V}vl2o  
E}xz7u   
~C}(\8g  
} 0C lX  
} >k$[hk*~  
//负责部分文件的抓取 fo/ D3  
**FileSplitterFetch.java FBR$,j;Y  
*/ se<i5JsSV  
package NetFox; Paae-EmC  
2(+RIu0d  
)![f\!'PI  
import java.io.*; 5W?yj>JR  
import java.net.*; Y|hzF:ll  
<7vIh0  
fK)ZJ_?w,@  
public class FileSplitterFetch extends Thread { ]%NO"HzF~  
G=r(SJq  
u#zP>!  
String sURL; //File URL W _PM!>8`  
long nStartPos; //File Snippet Start Position n4ds;N3Hd  
long nEndPos; //File Snippet End Position BxSk%$J  
int nThreadID; //Thread's ID . 1{vpX  
boolean bDownOver = false; //Downing is over 9pVf2|5hj  
boolean bStop = false; //Stop identical r6O7&Me<  
FileAccessI fileAccessI = null; //File Access interface @&~OB/7B:  
m~= ]^e  
]>VJ--fH  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1jZDw~  
{ 8>%jZ%`a  
this.sURL = sURL; d&[M8(  
this.nStartPos = nStart; o*O "\/pmF  
this.nEndPos = nEnd; 9E->;0-  
nThreadID = id; C:tSCNH[  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [[*0MA2Y  
} ?1-n\ka  
1cHSgpoJ  
=`7#^7Q9  
public void run() Ov~S2?E8  
{ '-nuH;r  
while(nStartPos < nEndPos && !bStop) zJy 89ib'  
{ UtW"U0A  
94qHY1rp  
0%A(dJA6  
try{ JT.\f,z&  
URL url = new URL(sURL); 7=QC+XSO  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (8@h F#N1  
httpConnection.setRequestProperty("User-Agent","NetFox"); @T,H.#bL  
String sProperty = "bytes="+nStartPos+"-"; S}v{^vR  
httpConnection.setRequestProperty("RANGE",sProperty); R>e3@DQ~  
Utility.log(sProperty); ~-`BSR  
(4{@oM#H6  
WDH[kJ  
InputStream input = httpConnection.getInputStream(); &, Zz  
//logResponseHead(httpConnection); +EiUAs~H  
?ck^? p7  
FkxhEat8  
byte[] b = new byte[1024]; >QZt)<[  
int nRead; @]ptY*   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o trTrh  
{ zZ+LisSs&  
nStartPos += fileAccessI.write(b,0,nRead); |bG[TOa  
//if(nThreadID == 1) xXY)KI N[  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %:be{Y6  
} 6ImV5^l  
7AtXG^lK  
{^$"/hj  
Utility.log("Thread " + nThreadID + " is over!"); Vg [5bJ5  
bDownOver = true; 0JZq:hUd  
//nPos = fileAccessI.write (b,0,nRead); RP@idz  
} xU\:Vid+A  
catch(Exception e){e.printStackTrace ();} d$?n6|4  
} MlC-Aad(  
} l&^[cR  
WfjUJw5x"s  
c;~Llj P  
//打印回应的头信息 RY/ Z~]  
public void logResponseHead(HttpURLConnection con) %`T^qh_dE  
{ LN6JH!  
for(int i=1;;i++) #u=O 5%.  
{ z5*O@_r+.b  
String header=con.getHeaderFieldKey(i); o2e h)rtB  
if(header!=null) !{~7)iq  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1'U%7#;E  
Utility.log(header+" : "+con.getHeaderField(header)); Y)j,(9  
else f?<M3P  
break; (zLIv9$  
} $5"-s]  
} O"-PNF,J  
2|NyAtPb5  
qyBK\WqaP  
public void splitterStop() VX>t!JP p  
{ AO7qs:+  
bStop = true; T#^6u)  
} <ZvPtW  
!RUo:b+  
gMK3o8B/  
} FivaCNA  
=cKk3kJC  
{)[g  
/* yExyx?j.  
**FileAccess.java .-26 N6S  
*//文件访问(定位,写) Vq7 kA "  
package NetFox; @k #y-/~?  
import java.io.*; eD1MP<>h  
np>!lF:  
*U^I `j[u  
public class FileAccessI implements Serializable{ ! tPK"k  
zr9Pm6Rl  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !skWe~/  
RandomAccessFile oSavedFile; ^t%M   
long nPos; n *0F  
tJ_@AcF  
.MPOUo/e  
public FileAccessI() throws IOException 43Uy<%yb>}  
{ K:50?r_-6  
this("",0); ;S27m]Q?  
} 3:Egqw  
9U1!"/F  
;RZa<2  
public FileAccessI(String sName,long nPos) throws IOException 7IW7'klkvD  
{ I}0 -  
oSavedFile = new RandomAccessFile(sName,"rw"); a#Gq J?nY  
this.nPos = nPos; 2m}]z.w#  
oSavedFile.seek(nPos); Yy~Dg  
} 9JeGjkG,  
/38Pp%  
)tg*dE  
public synchronized int write(byte[] b,int nStart,int nLen) ;.m[&h 0  
{ 8>+eGz|  
int n = -1; ]@]"bF!Dn  
try{ 8k% :w0H  
oSavedFile.write(b,nStart,nLen); E0Xu9IW/A  
n = nLen; zMg^2{0L  
} Dp'af4+%$  
catch(IOException e) IN*Z__l8j`  
{ iU|C<A%Hh  
e.printStackTrace (); t?&ajh  
} .qP zd(<T7  
[vJosbU;  
Nq1RAM  
return n; x6P^IkL:  
} >CA1Ub&ls  
$>`8'I  
p`C5jfI  
} Q'LU?>N)/  
PkO(Y!  
HM x9M$  
/* sbb{VV`I  
**SiteInfoBean.java <m\TZQBD  
*/ 8;bOw  
package NetFox; \Bf{/r5x  
!"">'}E1  
Va:jMN  
public class SiteInfoBean { -#hl& ^u$  
#7)6X:/O  
+%^xz 1m  
private String sSiteURL; //Site's URL V!4E(sX  
private String sFilePath; //Saved File's Path #]a0 51Y  
private String sFileName; //Saved File's Name Z r*ytbt  
private int nSplitter; //Count of Splited Downloading File |9@;Muq;  
IrK )N  
ng\S%nA&J  
public SiteInfoBean() Iu]P^8  
{//nSplitter的缺省值为5 L(iWFy1& T  
//default value of nSplitter is 5 { Uh/ ~zu  
this("","","",5); VE!h!`<k  
} 6HyQm?c>a  
,oR}0(^"\<  
E[ ,Ur`>:  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &BP%~  
{ /.vB /{2  
sSiteURL= sURL; WVKzh  
sFilePath = sPath; mZmwCS8  
sFileName = sName; 6B&':N98  
this.nSplitter = nSpiltter; v~j21`  
f"S^:F0  
l%U{Unwu  
} Rc @p!Xi  
%1S;y  
Y~,N,>nITu  
public String getSSiteURL() ^+I{*0{/[  
{ E` BL3+kQ  
return sSiteURL; R'He(x  
} PXWBc\  
)D Y?Y-n  
0I1bY]*  
public void setSSiteURL(String value) d(<[$ 3.  
{ W2s6!_AN  
sSiteURL = value; <a; <|Fm.  
} G7 b>r  
J'W6NitMr  
ZJ1 %  
public String getSFilePath() Enyx+]9  
{ ,iV|^]X3$/  
return sFilePath; a%cCR=s=  
} #A+ dj| b  
e2~&I`ct  
@-)jU!  
public void setSFilePath(String value) l!5fuB8  
{ P`0}( '"U  
sFilePath = value; R^4JM,v9x`  
} eh`n?C  
!/2u O5  
R1)v;^B|)  
public String getSFileName() %v5IR  
{ u[k0z!p_ c  
return sFileName; e'Njl?>3  
} 9l<f?OzAO  
>|IUjv2L  
(= #EJB1(  
public void setSFileName(String value) A%(t'z  
{ EdR1W~JZ  
sFileName = value; ,ELbm  
} |1!RvW:[!  
UaG })  
@'P\c   
public int getNSplitter() P3Ocfpf Bp  
{ ;d5d$Np@m&  
return nSplitter; l1 Nr5PT  
} !X5n'1&  
@~1}n/  
20h+^R3{Z  
public void setNSplitter(int nCount) v@n0ma=  
{ IHC {2 ^  
nSplitter = nCount; mQwP-s  
} PLoD^3uG)  
} Oc A;+}>  
3;v%78[&P  
{_[\k^98>  
/* df9 jT?l  
**Utility.java ebv"`0K$  
*/ 2":{3=oW~  
package NetFox; {zhajY7  
QTe>EJ12  
`!- w^~c  
public class Utility { ?OD43y1rzd  
jc0Trs{Jf  
;cpQ[+$nKp  
public Utility() KdN+$fe*g  
{ pA?kv]l(  
MeCHn2zwB  
R-[t 4BHn  
} o!$O+%4  
@3g$H[}  
//线程睡眠 BU;o$"L  
public static void sleep(int nSecond) A*x3O%zH  
{  iup "P  
try{ caH!(V}6  
Thread.sleep(nSecond); {)K H%  
} 4s_|6{ANS  
catch(Exception e) sR;^7(f!m  
{ ?j:U<TY)  
e.printStackTrace (); VV'*3/I  
} 8slOB>2#Y  
} 3{/[gX9  
Z)qts=  
//日志 {BI5lvx:  
public static void log(String sMsg) |i~Ab!*8n  
{ F4X0DRC,G  
System.err.println(sMsg); ,'}qLor  
} )}3!iDA  
$v \@mW*R  
42B_8SK  
public static void log(int sMsg) Bk44 wz2 X  
{ Or:a\qQ1  
System.err.println(sMsg); #Y>os3]  
} ] -}Zd\Rs  
} b~Q8&z2  
xtq='s8e  
P(|+1$#[  
/* {];8jdg/?  
**TestMethod.java _$vAitUe4S  
*/ q-<t'uhs[  
package NetFox; azKiXr#_(  
3v?R"2\qS  
|,)=-21&;  
public class TestMethod { &:@)ro CR  
&)Z!A*w]  
duT'$}2@>  
public TestMethod() >JUOS2  
{ ///xx/weblogic60b2_win.exe Yb? L:,a(I  
try{ 2^f6@;=M  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JK=0juv<E  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 79MF;>=tV  
SiteFileFetch fileFetch = new SiteFileFetch(bean); }Y`D^z~  
fileFetch.start(); b2vCr F;  
} \&#IK9x{  
catch(Exception e){e.printStackTrace ();} .tQeOZW'  
*w,C5 f  
qC:QY6g$N  
} ~|kSQ7O^  
C(!A% >  
W^"C|4G}  
public static void main(String[] args) L<H zPg  
{ <yg! D21Y  
new TestMethod(); 3 z~d7J  
} -)E nr6  
} NDYm7X*et  
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