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http断点续传简单实现(java)

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/* mOB\ `&h5  
**SiteFileFetch.java +{I\r|  
*/ s`B'vyoaa  
package NetFox; p\WUk@4  
import java.io.*; $!f$R`R^Q\  
import java.net.*; >guQY I@4,  
=FbfV*K 9  
zaZ}:N/w(z  
public class SiteFileFetch extends Thread { fz&}N`n  
uS'ji k}  
39j d}]e  
SiteInfoBean siteInfoBean = null; //文件信息Bean (Gn[T1p?  
long[] nStartPos; //开始位置 w(j9[  
long[] nEndPos; //结束位置 6bGD8 ;  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 P1QJ'eC;T  
long nFileLength; //文件长度 ^sKXn:)  
boolean bFirst = true; //是否第一次取文件 D'h2 DP!  
boolean bStop = false; //停止标志 s]iOC6v  
File tmpFile; //文件下载的临时信息 .{ -yveE  
DataOutputStream output; //输出到文件的输出流 j r[~  
WI6E3,ejB1  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) h 3&:"*A2  
public SiteFileFetch(SiteInfoBean bean) throws IOException DR /)hAE  
{ 4L e5Ms/  
siteInfoBean = bean; 76b7-Nj"  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); d eoM~r9s  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Ic K=E ]p  
if(tmpFile.exists ()) mz*z1`\7v\  
{ \bOjb\ w$  
bFirst = false; ?/( K7>`  
read_nPos(); 9pcf jx..  
} FW DuH`-5  
else x]oQl^ F  
{ d_uy;-3  
nStartPos = new long[bean.getNSplitter()]; /wE_eK.  
nEndPos = new long[bean.getNSplitter()]; !5j3gr ~  
} -y?Z}5-rs  
yU"G|Ex  
lrhAO"/1  
e<4z)  
} a*j <TR  
#sU~fq  
S I7B6c  
public void run() >k}/$R+  
{ ^P/D8cXa4  
//获得文件长度 7omGg~!k(  
//分割文件 dyzw J70K  
//实例FileSplitterFetch sjI[Vq  
//启动FileSplitterFetch线程 l;*lPRoW,  
//等待子线程返回 VaSNFl1_M  
try{ t`T\d\  
if(bFirst) iBQBHF   
{ O'-Zn]@.]  
nFileLength = getFileSize(); 4AOS}@~W  
if(nFileLength == -1) I ~L Q1 _  
{ LGROEn<*d  
System.err.println("File Length is not known!"); .k`*$1?73x  
} Y-q@~v Z]  
else if(nFileLength == -2) :.o=F`W  
{ _MbVF>JOx  
System.err.println("File is not access!"); -\'.JA_  
} Kn#xY3W6  
else 8[1DO1*P  
{ _8li4;F  
for(int i=0;i<nStartPos.length;i++) IHbow0'  
{ x;FO|fH  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); x_y>j)  
} 92aDHECo  
for(int i=0;i<nEndPos.length-1;i++) "gN*J)!x  
{ J )8pqa   
nEndPos = nStartPos[i+1]; Ot$cmBhw!  
} P}+|`>L  
nEndPos[nEndPos.length-1] = nFileLength; qa$[L@h>  
} t7oz9fSz=?  
} _c9 WWp?  
)fd-IYi-3  
[> &+*c  
//启动子线程 I0l.KiBm  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H]i+o6  
for(int i=0;i<nStartPos.length;i++) *T>#zR{  
{ FJjF*2 .  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F0BOhlK  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 86[RH!e  
nStartPos,nEndPos,i); R!/,E  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )1Ma~8Y%r  
fileSplitterFetch.start(); Eo { 1y  
} ZU| V+yT  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c(Uj'uLc  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7o965h  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P96Cw~<Q?  
nEndPos = " + nFileLength); UOLTCp?M;J  
// fileSplitterFetch[nPos.length-1].start(); I*+LJy;j  
I5TQ>WJbf  
Sg CqxFii  
//等待子线程结束 vy{rwZ$  
//int count = 0; k lP{yxU'n  
//是否结束while循环 M73VeV3DL  
boolean breakWhile = false; `r~`N`o5A  
,yHzo  
|z!q r}i  
while(!bStop) 3P+4S|@q(4  
{ 4hsPbUx9  
write_nPos(); .KiPNTh'  
Utility.sleep(500); ="5k\1W1M  
breakWhile = true; ]b0zkoD9<  
dDv{9D,  
bK_0NrXP  
for(int i=0;i<nStartPos.length;i++) m{:"1]  
{ */%$6s~  
if(!fileSplitterFetch.bDownOver) zK ' _e&*  
{ lgCHGv2@  
breakWhile = false; Vr&el  
break; 3JlC/v#0  
} P;)2*:--)  
} G zJ9N`  
if(breakWhile) S F&M (=w<  
break; 7.7Cluh5,  
[ -9)T  
Qag|nLoT  
//count++; ZfFIX5Qd\  
//if(count>4)  uD.  
// siteStop(); ~=`f]IL  
} ]iz_w`I\  
jHkyF`<+  
VRtbHam  
System.err.println("文件下载结束!"); 07$/]eO%C  
} S`pF7[%rp  
catch(Exception e){e.printStackTrace ();} ax-=n(   
} &_Cxv8  
g6rv`I $l  
vbr~<JT=  
//获得文件长度 q Axf5  
public long getFileSize() G*)s%2c>h  
{ W9 n^T+2  
int nFileLength = -1; 4u3 \xR?w6  
try{ httls>:xB|  
URL url = new URL(siteInfoBean.getSSiteURL()); RtW4 n:c  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]sX7%3P  
httpConnection.setRequestProperty("User-Agent","NetFox"); =1gDjF9|  
Y;fuh[#  
?,WUJH?^  
int responseCode=httpConnection.getResponseCode(); <h'8w  
if(responseCode>=400) =ied}a :[  
{ 'b LP ~  
processErrorCode(responseCode);  K&j' c  
return -2; //-2 represent access is error P/FrE~  
} k TFz_*6.  
'9^E8+=|  
w0#% AK  
String sHeader; zSEr4^Dk4  
bZxv/\  
b2a'KczV  
for(int i=1;;i++) 8&?^XcJ*x  
{ a^@+%?X  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c eqFQ  
//Utility.log(in.readLine()); ' " Bex`  
sHeader=httpConnection.getHeaderFieldKey(i); \V._Z>]  
if(sHeader!=null) $`E4m8fX  
{ OpYmTep#T\  
if(sHeader.equals("Content-Length")) P1dN32H o  
{ D*|( p6v1&  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G=vN;e_$_b  
break; (&q@~ dJ  
} 1UC2zM"  
} }'u3U"9)  
else 1oB$MQoc  
break; %(fL?  
} rU],J!LF  
} 1Pu ,:Jt  
catch(IOException e){e.printStackTrace ();} 55LgBD  
catch(Exception e){e.printStackTrace ();} AzZi{Q ?  
;9K[~  
"K 8nxnq  
Utility.log(nFileLength); ^GN5vT+:'  
,&0Z]*  
5@K\c6   
return nFileLength; JFe4/ V  
} cS4xe(n8  
"pYe-_"@  
'=$TyiU  
//保存下载信息(文件指针位置) 7Ez}k}aR<  
private void write_nPos() cnbo +U  
{ &/HoSj>HS  
try{ 2ed@HJu  
output = new DataOutputStream(new FileOutputStream(tmpFile)); OO$|9`a  
output.writeInt(nStartPos.length); yz2(_@R  
for(int i=0;i<nStartPos.length;i++) 'HCnB]1  
{ k@7kNMl  
// output.writeLong(nPos); =<Hy"4+?.  
output.writeLong(fileSplitterFetch.nStartPos); u]R$]&<  
output.writeLong(fileSplitterFetch.nEndPos); L+Eu d  
} Q^nG0<q+  
output.close(); CK=ARh#|  
} c$/<l5Uw  
catch(IOException e){e.printStackTrace ();} o94P I*.  
catch(Exception e){e.printStackTrace ();} $kv@tzO  
} W.IH#`-9E  
"8FSA`>=  
3zbXAR*  
//读取保存的下载信息(文件指针位置) tO7I&LNE  
private void read_nPos() l4zw]AYk+X  
{ Ny]lvgu9X  
try{ !f@XDW&R  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u9BjgK(M  
int nCount = input.readInt(); _$!`VA%  
nStartPos = new long[nCount]; t]4!{~,  
nEndPos = new long[nCount]; wBLsz/  
for(int i=0;i<nStartPos.length;i++) 7O"hiDQ  
{ lz- iCZ  
nStartPos = input.readLong(); PaNeu1cO  
nEndPos = input.readLong(); 9+t =|  
} L -YNz0A  
input.close(); $:(z}sYQ7  
} l`* ( f9Q  
catch(IOException e){e.printStackTrace ();} b1 H7  
catch(Exception e){e.printStackTrace ();} g(nK$,c  
} Ep<YCSQy$i  
:4U0I:J#  
;|;iCaD a+  
private void processErrorCode(int nErrorCode) moaodmt]x  
{ 72u db^  
System.err.println("Error Code : " + nErrorCode); Hl/7(FJqc>  
} ~oo'ky*H!  
ZOC#i i`:  
V\"1wV~E  
//停止文件下载 ^g[J*{+!W  
public void siteStop() %Sul4: D#  
{ k},>^qE  
bStop = true; .N!{ U  
for(int i=0;i<nStartPos.length;i++) v[smQO  
fileSplitterFetch.splitterStop(); BD4`eiu"  
0`6),R'x  
h mds(lv7  
} z|Ap\[GS  
} v~f'K3fLp  
//负责部分文件的抓取 `/0u{[  
**FileSplitterFetch.java 4QO/ff[ o  
*/ >IBTBh_ka  
package NetFox; m9woredS,  
/,LfA2^_j{  
W"|mpxp  
import java.io.*; .$P|^Zx,  
import java.net.*; mTJ"l(,3  
TOrMXcn!/  
'g~@"9'oe  
public class FileSplitterFetch extends Thread { _; 7fraqX  
gJKKR]4*  
><K!~pst}  
String sURL; //File URL (_ U^  
long nStartPos; //File Snippet Start Position -p]>Be+^x  
long nEndPos; //File Snippet End Position ZL=N[XW4'  
int nThreadID; //Thread's ID d@Q][7  
boolean bDownOver = false; //Downing is over j %H`0  
boolean bStop = false; //Stop identical NHAH#7]M&1  
FileAccessI fileAccessI = null; //File Access interface S~> 5INud  
ewym 1}o  
7 v~ro  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException P.h.M A]  
{ Z}+yI,  
this.sURL = sURL; 5j`v`[B;  
this.nStartPos = nStart; =U c$D*  
this.nEndPos = nEnd; rH.gF43O:  
nThreadID = id; k2.G%]j  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {-h, ZdH^  
} GG+5/hU  
CL1 oAk  
AEqq1A   
public void run() c.0]1  
{ (A uPZ  
while(nStartPos < nEndPos && !bStop) Zih ?Bm  
{ [;Fofu Z  
g|4w8ry  
n,sY\=vB  
try{ }[v~&  
URL url = new URL(sURL); HCazwX  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;ctU&`  
httpConnection.setRequestProperty("User-Agent","NetFox"); OXCQfT@\  
String sProperty = "bytes="+nStartPos+"-"; G0/>8_Q>Nr  
httpConnection.setRequestProperty("RANGE",sProperty); tr=@+WHp  
Utility.log(sProperty); 0;<OYbm3<  
dyO E6Ex  
C_Gzv'C"L  
InputStream input = httpConnection.getInputStream(); r.<JDdj  
//logResponseHead(httpConnection); 8lb-}=  
R04J3D|  
0D~=SekQ 9  
byte[] b = new byte[1024]; 1a8$f5  
int nRead; 11{y}J  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KoF iQ?  
{ ] D6|o5  
nStartPos += fileAccessI.write(b,0,nRead); H;y}-=J+  
//if(nThreadID == 1) .`J:xL%Z  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gt@SuX!@{^  
} l;0y-m1  
7=3O^=Q ^Q  
wDw<KU1UK  
Utility.log("Thread " + nThreadID + " is over!"); .[(P  
bDownOver = true; x5F@ad 9  
//nPos = fileAccessI.write (b,0,nRead); 8[R1A  
} mp:m`sh*i  
catch(Exception e){e.printStackTrace ();} 3I*uV!notJ  
} Ue!Q."  
} KTv4< c]  
C0(sAF@  
_Wma\(3$  
//打印回应的头信息  C0<YH "  
public void logResponseHead(HttpURLConnection con) $ eX*  
{ :\bfGSD/gd  
for(int i=1;;i++) ERC<Dd0  
{ lD3)TAW@o  
String header=con.getHeaderFieldKey(i); Ay%:@j(E  
if(header!=null) (}"S) #C  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QptOQ3!  
Utility.log(header+" : "+con.getHeaderField(header)); GA@ Ue9  
else M=[th  
break; o(Kcs-W2  
} jb3.W  
} j+Zt.KXjT  
`xIh\q  
q,@+^aZ  
public void splitterStop() [+gzdLad  
{ r<|nwFJ  
bStop = true; F.0d4:A+  
} Tq#<Po $  
Mz\yPT;Y  
,CKvTxz0  
} ^IgS  
4>_d3_1sn  
rhoeZ  
/* `:4MMr91  
**FileAccess.java @H+~2;B,  
*//文件访问(定位,写) i@6wO?Tv  
package NetFox; \xeVDKJH+n  
import java.io.*; j{"[Ec  
o8tS  
^6qjSfFW}  
public class FileAccessI implements Serializable{ nuxd S ,  
XN(tcdCG  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JCcQd 01z  
RandomAccessFile oSavedFile; k9&@(G[K3  
long nPos; Q"'V9m7 i  
VF= Z`  
^W}MM8 '  
public FileAccessI() throws IOException AsAFUuI  
{ ls]H6z*q  
this("",0); A;T[['  
} ob]dZ  
doH2R @  
B.6`cM^  
public FileAccessI(String sName,long nPos) throws IOException >-zkB)5<,#  
{ L~ 2q1  
oSavedFile = new RandomAccessFile(sName,"rw"); [ro t  
this.nPos = nPos; AWL[zixR  
oSavedFile.seek(nPos); 8T7f[?  
} Uz $ @(C  
1 KB7yG-#6  
7t3X`db  
public synchronized int write(byte[] b,int nStart,int nLen) O4N-_Kfp/  
{ Efvq?cG&  
int n = -1; X(b1/lzA  
try{ )2]a8JVf  
oSavedFile.write(b,nStart,nLen); /6jGt'^U  
n = nLen; #]X2^ND4 7  
} ? rQc<;b  
catch(IOException e) ZMe}M!V  
{ pX^=be_  
e.printStackTrace (); ~M; gM]r;  
} DUhT>,~]  
,0h3x$l)   
s_v }=C^  
return n; EzUPah  
} "\<P$&`HA  
3@'lIV ?,q  
p#z;cjfSt  
} v23TL  
;}f6Y['z  
FJW`$5?  
/* dy'X<o^?W  
**SiteInfoBean.java ^GrNfB[Qu  
*/ 4{g:^?1=  
package NetFox; 'T6B_9GQ8  
Wn2Ny jX  
B #;s(O  
public class SiteInfoBean { R%qX_m\0  
4RlnnXY  
Z3Bo@`&?  
private String sSiteURL; //Site's URL P*}9,VoY  
private String sFilePath; //Saved File's Path m9v"v:Pw  
private String sFileName; //Saved File's Name t%0r"bTi  
private int nSplitter; //Count of Splited Downloading File f2BS[$oV4  
iXt4|0  
V+P8P7y37B  
public SiteInfoBean() u Eu6f  
{//nSplitter的缺省值为5 V< 2IIH5^  
//default value of nSplitter is 5 QJ[(Y@ O6a  
this("","","",5); _G_ &Me0  
} *2w_oKE'+5  
,?P8m"  
v=dKcruR:  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WHZe)|n  
{ FSI]k:  
sSiteURL= sURL; B:.;,@r]  
sFilePath = sPath;  O6M}W_  
sFileName = sName; & y#y>([~  
this.nSplitter = nSpiltter; 6R3"L]J  
FKDamHL<  
j+z'  
} p,M3#^ q  
xCDA1y;j  
KZ367&>b7  
public String getSSiteURL() ph}wnIW]  
{ D2hAlV)i(  
return sSiteURL; z7NGpA(  
} _OyP>| L'  
&>+I7Ts]  
6E)uu; 8  
public void setSSiteURL(String value) ?NL&x  
{ [Gh%nsH  
sSiteURL = value; Res"0Q  
} uFA|r X  
Wl9I`Itg  
\N'hbT=  
public String getSFilePath() H|UV+Q0,  
{ / h 2*$  
return sFilePath; X r  
} OuYE-x2]x"  
c_D,MW\IC  
]$XBd{\D{  
public void setSFilePath(String value) 5 b#" G"  
{ v4Fnh`{  
sFilePath = value; >8F{lbEe  
} FrAqTz  
.:r2BgL  
ctwhfS|Y0  
public String getSFileName() goBKr: &]w  
{ LB64W ;#h  
return sFileName; >M8^ Jgh  
} 5~kW-x  
toYg$IV  
 q~:'R  
public void setSFileName(String value) ;/hH=IT  
{ ba:mO$  
sFileName = value; l/y Kc8^<  
} t?#vb}_  
YWn6wzu%Vc  
#:Sy`G6!?  
public int getNSplitter() twJ|Jmd  
{ 7zJh;f/  
return nSplitter; ;'WzfJ!q  
} V.P5v {  
wr;|\<c  
^S;RX*  
public void setNSplitter(int nCount) )2<B$p  
{ ,P; a/{U  
nSplitter = nCount; '#An+;x{  
} ,N@Icl  
} -$]DO5fY  
Oa_o"p<Lr  
6GrMcI@hS  
/* t$PnQ@xu  
**Utility.java ~XT a=  
*/ p#8LQP~0$  
package NetFox; E't G5,/m  
a*n%SUP  
[:hy  
public class Utility { ,ov v  
w or'=byh\  
,h(f\h(9  
public Utility() SUnmp  
{ ~|B!. +  
(a)@<RF`Q}  
@!O&b%8X%  
} {;(g[H=q;  
OTtanJ?  
//线程睡眠 PuoJw~^h  
public static void sleep(int nSecond) X#NeB>~  
{ :7PSZc:xE  
try{ !=Kay^J~.  
Thread.sleep(nSecond); ht74h  
} [m+O0VK$  
catch(Exception e) m$y$wo<K[7  
{ ~9/nx|%D  
e.printStackTrace (); fz?Wr: I  
} u1|Y;*  
} @Q1F#IU  
Ud(dWj-/  
//日志 rM~IF+f0XD  
public static void log(String sMsg) N+@@EOmH  
{ 6;c{~$s~[  
System.err.println(sMsg); qA_DQ):  
} }lvP|6Y: y  
WxP4{T* <  
T+{'W  
public static void log(int sMsg) >_% g8T'  
{ 3z. >b  
System.err.println(sMsg); %fSk "%u%<  
} n\)f.}YD8d  
} *l8vCa9Y  
owVUL~  
_ ~$0cj<  
/* 4a-F4j'  
**TestMethod.java >v4~:n2D  
*/ RKZk/ly  
package NetFox; J)& +y;.  
[5:7 WqB  
v2z/|sG  
public class TestMethod { H~K2`Cr)4  
~PvzUT-^  
Re ur#K  
public TestMethod() bg. KkJMrR  
{ ///xx/weblogic60b2_win.exe .F|WQ7Mu  
try{ TBp5xz`  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @Oay$gP{T  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R63d `W  
SiteFileFetch fileFetch = new SiteFileFetch(bean); w~-d4MNM  
fileFetch.start(); cO+`8`kv  
} bW3o%srxa  
catch(Exception e){e.printStackTrace ();} dgD%I  
hiM!htc;M  
xf SvvCy  
} WSwmX3rn  
a'~y'6  
KO"iauW  
public static void main(String[] args) GlZDuU  
{ kniMXeiu  
new TestMethod(); q|2C>{8  
} sVnu Sm  
} jO.E#Ei}~  
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