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http断点续传简单实现(java)

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/* G 4 C 7  
**SiteFileFetch.java }@jT-t]P  
*/ ,7izrf8  
package NetFox; #zw 'H9l  
import java.io.*; H3jb{S b  
import java.net.*; Z sbE  
]}jY] l  
+X7+:QQ }  
public class SiteFileFetch extends Thread { T\o!^|8  
YGr^uTQb  
%/=#8v4*  
SiteInfoBean siteInfoBean = null; //文件信息Bean /,2${$c!  
long[] nStartPos; //开始位置 x2H?B` 5  
long[] nEndPos; //结束位置 ;PhX[y^*  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 L51uC ,QF  
long nFileLength; //文件长度 }_o!f V  
boolean bFirst = true; //是否第一次取文件 `K \(I#z  
boolean bStop = false; //停止标志 H He~OxWg  
File tmpFile; //文件下载的临时信息 "e~"-B7(\Y  
DataOutputStream output; //输出到文件的输出流 ZYD3[" ~x  
OcGHMGdn  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 9oJ=:E~CP  
public SiteFileFetch(SiteInfoBean bean) throws IOException U/bQ(,3}  
{ e025m}%SU  
siteInfoBean = bean; Gv zw=~8  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); '}T6e1#JV  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); $NhKqA`0  
if(tmpFile.exists ()) qddP-uN  
{ &d^u$Y5  
bFirst = false; \i$WXW]|  
read_nPos(); W]DZ'  
} aqAWaO  
else tL~?)2uEN  
{ hh>mX6A  
nStartPos = new long[bean.getNSplitter()]; ckPI^0A!  
nEndPos = new long[bean.getNSplitter()]; f")*I  
} J|2OmbJe  
N HL{.8L{  
['rqz1DL5  
VwV`tKit  
} -964#>n[  
naoH685R4  
Qs.g%  
public void run() DEkFmmw   
{ pn6!QpV5  
//获得文件长度 V_"K  
//分割文件 ?H_'L4Wv  
//实例FileSplitterFetch A 9HJWKO  
//启动FileSplitterFetch线程  R)?zL;,x  
//等待子线程返回 ^UAL5}CQt  
try{ #D&]5"0cX  
if(bFirst) D#n^U `\if  
{ 1Q ^YaHzuW  
nFileLength = getFileSize(); yPqZ ,  
if(nFileLength == -1) aj<=]=hr  
{ NuqWezJm&  
System.err.println("File Length is not known!"); uk~4R@=&H  
} ;/8oP ;X2  
else if(nFileLength == -2) $}G03G@  
{ 1 k}U+  
System.err.println("File is not access!"); HrZ\=1RB  
} #}rv)  
else UR&Uwa&.  
{ c~+;P(>  
for(int i=0;i<nStartPos.length;i++) Z'~yUo=  
{ v8xNtUxN  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); &S"o jbb  
} EK6fd#J?1  
for(int i=0;i<nEndPos.length-1;i++) :}Tw+S5  
{ d= -/'_'  
nEndPos = nStartPos[i+1]; $6X CHVx  
} N3Jfp3_b@  
nEndPos[nEndPos.length-1] = nFileLength; d M&BnI  
} '<C I^5^  
} |NcfR"[c  
nsJN)Pt  
'_~=C-g  
//启动子线程 yjbqby7  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4S]`S\w  
for(int i=0;i<nStartPos.length;i++) {{?[b^  
{ @,63%  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b1}P3W  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <|s9@;(I  
nStartPos,nEndPos,i); nKJJ7 R L  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uYPdmrPB?l  
fileSplitterFetch.start(); 8h#/b1\  
} n(gw%w+\7  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j 6~#_t[  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O0{M3-  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $:%?-xy(  
nEndPos = " + nFileLength); T/" 6iv\1  
// fileSplitterFetch[nPos.length-1].start(); XTHy CK  
3JiDi X"|  
Cr,UP8MO  
//等待子线程结束 )hHkaI>eYv  
//int count = 0; (N U*PQY6  
//是否结束while循环 F(8>"(C  
boolean breakWhile = false; dE+xU(\, w  
qF{u+Ms  
8}0W_CU,  
while(!bStop) l("Dw8 H  
{ )j40hrR  
write_nPos(); 7mSVL\\^  
Utility.sleep(500); E lt=/,v`!  
breakWhile = true; N4%q-fi  
~h] <E  
RpE69:~PV  
for(int i=0;i<nStartPos.length;i++) d FF[2  
{ Nkt(1?:-'  
if(!fileSplitterFetch.bDownOver) &Z_W*D  
{ W^W^5-'"D,  
breakWhile = false; +'H_sMmi{  
break; qJj;3{X2  
} [e )j,Q1  
} 1.0S>+^JE  
if(breakWhile) Z,Z34:-  
break; )z9)oM\  
j5ZeYcQ-  
Vc3tKuMsiX  
//count++; kL,{H~iq;  
//if(count>4) c,1Yxg]|  
// siteStop(); ?Ovl(4VG  
} ]k%Yz@*S  
'w`:p{E  
(z0S5#g ,x  
System.err.println("文件下载结束!"); o[Yxh%T  
} nJ#uz:(w,  
catch(Exception e){e.printStackTrace ();} ~ jb6  
} s% "MaDz  
/a%5!)NE%  
K+D`U6&  
//获得文件长度 #N%xr'H  
public long getFileSize() u{'bd;.7  
{ 5tg  
int nFileLength = -1; +Eh1>m  
try{ 4!<8Dd  
URL url = new URL(siteInfoBean.getSSiteURL()); " z\T$/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5B!l6ST  
httpConnection.setRequestProperty("User-Agent","NetFox"); BF2,E<^A  
jR S0(8  
/i$ mIj`  
int responseCode=httpConnection.getResponseCode(); ^0 R.U+?+  
if(responseCode>=400) <8[BB7  
{ BhkJ >4#  
processErrorCode(responseCode); lvIKL!;H  
return -2; //-2 represent access is error TdI5{?sW  
} D*Y4B ?,  
(b Q1,y  
^ad p<?q4  
String sHeader; g]R }w@nJ  
-$L53i&R  
<k'=_mC_  
for(int i=1;;i++) +qe!KPk2  
{ ow*) 1eo  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ci>+Zi6  
//Utility.log(in.readLine()); eOjoxnD-$  
sHeader=httpConnection.getHeaderFieldKey(i);  R:98'`X=  
if(sHeader!=null) D[m;rcl  
{ U7.3`qd"  
if(sHeader.equals("Content-Length")) ~]DGf(   
{ Qj? +R F6(  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [y| "iSD  
break; {%xwoMVc+  
} _e$15qW+  
} a|`Pg1j#  
else KFdTw{GlJ7  
break; :3$WY<  
} [!4p5;  
} z%;b-PpS  
catch(IOException e){e.printStackTrace ();} bE.,)GY  
catch(Exception e){e.printStackTrace ();} NyI0 []z  
'<~l% q  
j^T.7Zv  
Utility.log(nFileLength); m UpLD+-j  
@ 9D, f  
kt.z,<w5O  
return nFileLength; +~\1Zgw  
} |ul25/B B  
5BCXI8Ox9x  
f n )m$\2  
//保存下载信息(文件指针位置) *SQ hXTn  
private void write_nPos() ~h 6aw  
{ kD S  
try{ >S3iP?V7  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9S@PY_ms  
output.writeInt(nStartPos.length); 6Yebc_, R  
for(int i=0;i<nStartPos.length;i++) +M!f}=H  
{ pi:%Bd&F  
// output.writeLong(nPos); r k;k:<c  
output.writeLong(fileSplitterFetch.nStartPos); ^AK<]r<?L?  
output.writeLong(fileSplitterFetch.nEndPos); WY#A9i5Ge  
}  XeDiiI  
output.close(); `;4P?!WG  
} Ro$'|}(+A  
catch(IOException e){e.printStackTrace ();} K O"U5v  
catch(Exception e){e.printStackTrace ();} =4uL1[0'  
} Mib(J+Il  
%mPIr4$Pg  
e5_a.c  
//读取保存的下载信息(文件指针位置) U7O~ch[,  
private void read_nPos() ?9nuL}m!a  
{ $ 5ZBNGr  
try{ {^2``NYM_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eWSA  
int nCount = input.readInt(); PXG)?`^NX  
nStartPos = new long[nCount]; `q7O\  
nEndPos = new long[nCount]; bB@1tp0+  
for(int i=0;i<nStartPos.length;i++) 6lOT5C eJ"  
{ `P<}MeJ\l  
nStartPos = input.readLong(); !`L%wS  
nEndPos = input.readLong(); 0Lmq?D  
} 9F)+p7VJq  
input.close(); n#Xi Co_\  
} "hi?/B#d  
catch(IOException e){e.printStackTrace ();} g-"@%ps  
catch(Exception e){e.printStackTrace ();} x zu)``?  
} 4Tgy2[D?q  
2{Nv&ZX?  
% 1ZJi}~  
private void processErrorCode(int nErrorCode) yEyx.Mh.Af  
{ dO}6zQ\  
System.err.println("Error Code : " + nErrorCode); a]-F,MJ  
} Y3+DTR0|'  
iTF`sjL  
&2[OH}4  
//停止文件下载 8R"c}87  
public void siteStop() hdt;_qa   
{ 0(A`Ia  
bStop = true; hu0z):>y  
for(int i=0;i<nStartPos.length;i++) A@xa$!4}  
fileSplitterFetch.splitterStop(); ;`',M6g  
F7lhLly  
SYd4 3P A  
} U/9xO"b{.  
} 68JYA?  
//负责部分文件的抓取 d\dh"/_$  
**FileSplitterFetch.java WG>Nm89  
*/ lYldq)qB{  
package NetFox; -qaJ@T+J+7  
5H#f;L\k  
\=PnC}7I  
import java.io.*; } M-^A{C\%  
import java.net.*; {Qbg'|HO=l  
7{>mm$^|V  
<5(P4cm9  
public class FileSplitterFetch extends Thread { _0dm?=  
_|reo6  
VWf&F`^B(  
String sURL; //File URL 9`  
long nStartPos; //File Snippet Start Position N Q~keN  
long nEndPos; //File Snippet End Position 5e=9~].7  
int nThreadID; //Thread's ID S?ELFq(g  
boolean bDownOver = false; //Downing is over 3y?I^ .B  
boolean bStop = false; //Stop identical 4{4VC"fa  
FileAccessI fileAccessI = null; //File Access interface cB#5LXbCE  
*P2_l Q=  
y(/"DUx  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Kab"r_'  
{ Qc1NLU9:  
this.sURL = sURL; KSkT6_<  
this.nStartPos = nStart; +*&bgGhT  
this.nEndPos = nEnd; pFb }5Q  
nThreadID = id; __N< B5E  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VbX+`CwH  
} *YH5kX  
art L  
L kYcAY$w  
public void run() Ug(;\*yg  
{ U4;r.#qw,  
while(nStartPos < nEndPos && !bStop) APY^A6^:j  
{ ;PM(q<@\  
&[71~.Od  
K|[p4*6  
try{ D>tex/Of3  
URL url = new URL(sURL); ,5}%_  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @p` *MWU  
httpConnection.setRequestProperty("User-Agent","NetFox"); fNR2(8;}  
String sProperty = "bytes="+nStartPos+"-"; q,S[[{("  
httpConnection.setRequestProperty("RANGE",sProperty); -;]m4R)z  
Utility.log(sProperty); KA~eOEj M  
LF6PKS  
[0vgA#6I  
InputStream input = httpConnection.getInputStream(); *Rm"3S  
//logResponseHead(httpConnection); ws}cMX]*  
Xa o*h(Q@L  
,',  S  
byte[] b = new byte[1024]; )B"k;dLm  
int nRead;  W^dk:  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) })#VO-J  
{ T($d3Nn1  
nStartPos += fileAccessI.write(b,0,nRead); 4mHR+SZy  
//if(nThreadID == 1) V9KI?}q:W  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5PF?Eq   
} 0 PdeK'7  
E3..$x-/  
M9[52D!{  
Utility.log("Thread " + nThreadID + " is over!"); 7Yv1et |  
bDownOver = true; rgq~lZ.U4K  
//nPos = fileAccessI.write (b,0,nRead); Qc4r?7S<  
} @QOlo -u  
catch(Exception e){e.printStackTrace ();} 1f}YKT  
} ZVu_E.4.  
} QjT$.pU d  
f6/<lSoW  
BQWhTS7  
//打印回应的头信息 yV"k:_O{  
public void logResponseHead(HttpURLConnection con) r_R( kns  
{ xA7>";sla[  
for(int i=1;;i++) (U_`Q1Jo  
{ vbA<=V*P  
String header=con.getHeaderFieldKey(i); Kd='l~rby  
if(header!=null) "Y'MuV'x  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >T{Gl/? p  
Utility.log(header+" : "+con.getHeaderField(header)); M[eq)a$  
else 3{:AG,G  
break; Y5mQY5u|  
} jpwR\"UJ  
} ;*{"|l qe  
qb$&BZj]|  
T'^ Do/  
public void splitterStop() ) |t;nK,  
{ y<9' 3\  
bStop = true; 8Cx6Me>,=  
}  lL\%eQ  
>b;o&E`\  
4*0C_F@RX  
} sA(d_ Yu_  
wak:"B[  
jm ORKX+)  
/* ?T1vc  
**FileAccess.java q g2 fTe  
*//文件访问(定位,写) og[cwa_  
package NetFox; % _.kd"  
import java.io.*; Bm>>-nG;  
rtSG- _[i  
;OMR5KAz  
public class FileAccessI implements Serializable{ !k3 eUBF  
cy-o@U"s8  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $.+_f,tU  
RandomAccessFile oSavedFile; kuq&8f~!  
long nPos; 2`'g 9R  
~:krJ[=  
qkbGM-H%U  
public FileAccessI() throws IOException zH5pe  
{ n2V $dF4m  
this("",0); #"qP4S2  
} N%f% U  
n 9>**&5L  
C ^IPddw>  
public FileAccessI(String sName,long nPos) throws IOException W5*Kq^6Pd  
{ b)+;=o%  
oSavedFile = new RandomAccessFile(sName,"rw"); w!%"b03q  
this.nPos = nPos; 4j1$1C{  
oSavedFile.seek(nPos); Wa5B;X~  
} \:BixBU7  
\; voBU  
eae`#>XP  
public synchronized int write(byte[] b,int nStart,int nLen) ^j!2I&h1  
{ h}y]Pt?  
int n = -1; Zxw cqN  
try{ ^7Rc\   
oSavedFile.write(b,nStart,nLen); Yi?v |H<a  
n = nLen; 5i@WBa  
} 9,?7mgZ p  
catch(IOException e) 1j*E/L  
{ y3 "+4e  
e.printStackTrace (); 5La' I7q  
} `nCVO;B  
eH_< <Xh!v  
XfQK kol  
return n; J))U YJO  
} fi~jT"_CI  
,W|cyQ  
$L4h'(s  
} rT|wZz9$@  
gF>t+"+ x  
im3BQIPR  
/* 4%$#   
**SiteInfoBean.java it$w.v+W7V  
*/ } *jmW P  
package NetFox; +;ylld  
I=pFGU  
|s'5 ~+  
public class SiteInfoBean { i7b^b>B|e  
8|{d1dy  
r i/CLq^D  
private String sSiteURL; //Site's URL dw>1Ut{"3  
private String sFilePath; //Saved File's Path P:>]a$Is  
private String sFileName; //Saved File's Name 5S*aZ1t18  
private int nSplitter; //Count of Splited Downloading File 5m yQBKE  
MW2{w<-]7  
Qt\^h/zjG  
public SiteInfoBean() /o^/ J~/3  
{//nSplitter的缺省值为5 "-Yj~  
//default value of nSplitter is 5 z5J$".O`  
this("","","",5); (nwp s  
} @R_ON"h  
.(7m[-iF!  
+a"f)4\  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O+?vQ$z  
{ 3wMnTT"At  
sSiteURL= sURL; LP'wL6#  
sFilePath = sPath; `^HK-t4q  
sFileName = sName; ]1 jhy2j  
this.nSplitter = nSpiltter; \4KV9wm  
aH_0EBRc  
+i~kqiy.  
} T0{X,  
aH dQi,=z  
h0?w V5H  
public String getSSiteURL() W2&(:C8V@  
{ \30rF]F`l  
return sSiteURL; N/zP!%L  
} d"tR ?j  
l<;~sag  
z?@N+||,.  
public void setSSiteURL(String value) Nt|Fw$3*5{  
{ *\Lr]6k  
sSiteURL = value; :O7n*lwx  
} je`Inn<  
Ro_jfM  
\hWac%#  
public String getSFilePath() -zzoz x]S=  
{ %NDr5E^cc  
return sFilePath; ,h9?o  
} _C)\X(;  
3lTnfc&  
&x\cEI)!  
public void setSFilePath(String value) 4t-l@zFWb  
{ [V_+/[AA)  
sFilePath = value; Q-7L,2TL  
} i<(~J4}b  
NwVhJdo  
]=p^32  
public String getSFileName() BV6B:=E0  
{ $*:g~#bh  
return sFileName; N@Q_5t0bk  
} a2[rY  
e{H(  
n]6-`fpD  
public void setSFileName(String value) #-o 'g!  
{ T!I3.  
sFileName = value; +KaVvf  
} g4y& 6!g  
R9  Y@I  
+sV~#%%  
public int getNSplitter() !;4Hh)2  
{ <I#M^}`  
return nSplitter; +`iJ+  
} H>Ucmd;ay  
dUUg}/  
' &3,qT  
public void setNSplitter(int nCount) wD:2sri  
{ :cf#Tpq"  
nSplitter = nCount; r@}8TE*|P  
} FU(2,Vl  
} Ylyk/  
xS:n  
0cDP:EzR;  
/* RL )~J4Y  
**Utility.java 8rjD1<  
*/ tyWDa$u,u  
package NetFox;  d0i|^  
lwz\" 8  
a;v4R[lQ  
public class Utility { F+ 7*SImv6  
$fB j}\o  
h?H|)a<^9  
public Utility() $wn0oIuW  
{ [k0/ZfFwV  
vvu $8n  
M ziOpraj  
} Wffz&pR8  
&E1m{gB(  
//线程睡眠 Y;'SD{On  
public static void sleep(int nSecond) $}'(%\7"  
{ ~4|Trz2T  
try{ 'c_K[p$  
Thread.sleep(nSecond); 5f MlOP_  
} Pf/8tXs}  
catch(Exception e) 0yvp>{;p  
{ CB X}_]9X  
e.printStackTrace (); 1 +Ue m  
} 1J72*`4OK  
} S;y4Z:!  
E [6:}z<  
//日志 >t<\zC|~w  
public static void log(String sMsg) r6R@"1/  
{ c-v-U O%  
System.err.println(sMsg); RehraY3q  
} B=$O4nW_b  
?20R\ ]U  
$7ix(WL<%  
public static void log(int sMsg) HOF=qE*p  
{ =LODX29  
System.err.println(sMsg); I!Z"X&  
} i(OeE"YA  
} 6B%  h  
!A1~{G2VL_  
z [ 'G"yCi  
/* $PI9vyS  
**TestMethod.java YRCs&tgs  
*/ mU~&oU  
package NetFox; n I&p.i6  
,tcUJ}l  
89;@#9  
public class TestMethod { 6Ol9P56j  
H9PnJr8 \  
0:>hK\F#  
public TestMethod() X:I2wJDs\  
{ ///xx/weblogic60b2_win.exe  jr_z ?  
try{ f0j]!g  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "*.N'J\  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }r!+wp   
SiteFileFetch fileFetch = new SiteFileFetch(bean); t=xEUOQAn  
fileFetch.start(); qTN%9!0@9  
} 9(nq 4 HvI  
catch(Exception e){e.printStackTrace ();} ,lStT+A  
,i??}Wm5G  
.}v" `>x  
} T1*.3_wtP  
lixM0  
cJv/)hRaz  
public static void main(String[] args) {=?(v`88  
{ *coUHbP9>  
new TestMethod(); AWYlhH4c?t  
} >;' 0ymG.`  
} P"l'? `  
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