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http断点续传简单实现(java)

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/* h. (;GJO  
**SiteFileFetch.java #HuA(``[d  
*/ O"^a.`27  
package NetFox; &P{p\v2Y  
import java.io.*; BSu)O~s  
import java.net.*; 7f Tg97eF  
Is6']bYh  
^'I5]cRa  
public class SiteFileFetch extends Thread { M7<#=pX&  
^RyTK|SQ  
o`8+#+@f7  
SiteInfoBean siteInfoBean = null; //文件信息Bean /e?ux~f|  
long[] nStartPos; //开始位置 0G\myv  
long[] nEndPos; //结束位置 KJ^GUqVl  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 =U7D}n hS-  
long nFileLength; //文件长度 S}[:;p?F`  
boolean bFirst = true; //是否第一次取文件 (DMnwqr  
boolean bStop = false; //停止标志 hUhp2ibEs  
File tmpFile; //文件下载的临时信息 (:Hbtr I  
DataOutputStream output; //输出到文件的输出流 O9=H [b  
p,u<g JUL  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) KIBZQ.uG  
public SiteFileFetch(SiteInfoBean bean) throws IOException c)!s[oL  
{ S1= JdN  
siteInfoBean = bean; fQ.>G+0 I>  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); zcWxyLifl0  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); RGA*7  
if(tmpFile.exists ()) 5m7Ax] \  
{ I nK)O ';  
bFirst = false; P5xmLefng  
read_nPos(); wYMX1=  
} XhD fI &  
else *n_4Rr  
{  wY_-  
nStartPos = new long[bean.getNSplitter()]; ZUJOBjb` K  
nEndPos = new long[bean.getNSplitter()]; c2mt<DtWW  
} Ru')X{]25  
)zt4'b\)v  
<$6'Mzf  
{BCj VmY  
} HeifFJn  
N5Mz=UgB  
EM w(%}8w  
public void run() X|1YGZJ  
{ @d^h/w  
//获得文件长度 (4f9wrK  
//分割文件 "3oU (RA  
//实例FileSplitterFetch 7-IeJ6,D  
//启动FileSplitterFetch线程 :@Dos'0Px  
//等待子线程返回 'I>#0VRr  
try{ [_hhC  
if(bFirst) FY S83uq0  
{ Bg0cC  
nFileLength = getFileSize(); _";pk  _  
if(nFileLength == -1) xy3%z  
{ vl~   
System.err.println("File Length is not known!"); `srZ#F5  
} *>$)#?t  
else if(nFileLength == -2) &p4<@k\L  
{ AX RNV  
System.err.println("File is not access!"); G5f57F  
} _:p_#3s$  
else V"jnrNs3  
{ s'Q^1oQM2h  
for(int i=0;i<nStartPos.length;i++) >b?)WNk  
{ z ;Nk& <?  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); R./6Q1  
} K/+C6Y?  
for(int i=0;i<nEndPos.length-1;i++) 10IPq#Jj  
{ [gp:nxyfQm  
nEndPos = nStartPos[i+1]; Iw7r}G  
}  ly%B!P|  
nEndPos[nEndPos.length-1] = nFileLength; i O|,,;_  
} rg/vxTl  
} j$oZIV7  
emPm^M5/K  
oz-I/g3go  
//启动子线程 :=eUNH  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ucPMT0k  
for(int i=0;i<nStartPos.length;i++) &it/@8yH  
{ (+ anTA=  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l*H"]6cXRL  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n1(X%%2  
nStartPos,nEndPos,i); &)jZ|Q~  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .{Oq)^!ot  
fileSplitterFetch.start(); m9c T}x&j  
} r['C.S6  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9G/2^PI  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DJ0T5VE W3  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \%Q rN+WQ  
nEndPos = " + nFileLength); *v/*_6f*  
// fileSplitterFetch[nPos.length-1].start(); :]Qx T8B  
E2kRt'~N  
G@!9)v]9  
//等待子线程结束 hP<qKVy  
//int count = 0; Q 9<_:3  
//是否结束while循环 >D62l*VC)  
boolean breakWhile = false; r!,V_a4n  
+ aqo8'a  
Kp8T;&<Iay  
while(!bStop) s2=X>,kz?  
{ S9oGf  
write_nPos(); nW'x#0-  
Utility.sleep(500); !PIdw~YC  
breakWhile = true; S]/ +n>  
D07u?  
m kf{_!TK  
for(int i=0;i<nStartPos.length;i++) PzDgl6C  
{ Pv.@Y 30  
if(!fileSplitterFetch.bDownOver) ved Qwzh  
{ S6tH!Z=(g  
breakWhile = false; {o%R~{6  
break; .Kwl8xRg  
} (C@@e'e  
} 3y,?>-  
if(breakWhile) 7'uc;5:  
break; !I_4GE,  
!#qB%E]a  
uZI a-b  
//count++; CHI(\DXNs  
//if(count>4) ;g]+MLV9  
// siteStop(); 4HE4e  
}  +'.Q-  
!;Nh7vG  
7*"LW  
System.err.println("文件下载结束!"); 'Sh5W%NM  
} \9QOrjiw  
catch(Exception e){e.printStackTrace ();} #sZes  
} oyw1N;K  
&[5az/Hj*  
),,vu  
//获得文件长度 5-^twXC&  
public long getFileSize() $8r:&Iw  
{ A,qG*lv  
int nFileLength = -1; +(%[fW  
try{  64fG,b  
URL url = new URL(siteInfoBean.getSSiteURL()); Kjw\SQ)2~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o w[qpP[  
httpConnection.setRequestProperty("User-Agent","NetFox"); p]4 sN  
3IFU{0a`  
#mYxO  
int responseCode=httpConnection.getResponseCode(); =YIQ _,{u  
if(responseCode>=400) HXI}f\6x  
{ E:k?*l  
processErrorCode(responseCode); 063;D+  
return -2; //-2 represent access is error (Lnh> '2  
} ] ),' =@  
R 0}%   
sXu+F2O  
String sHeader; dZmq  
y>8?RX8  
sN2l[Ous  
for(int i=1;;i++) vE(Hy&Q&  
{ +)S X  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z, [ +  
//Utility.log(in.readLine()); VIzZmd  
sHeader=httpConnection.getHeaderFieldKey(i); q?&&:.H"?5  
if(sHeader!=null) &=bI3-  
{ 2-84  
if(sHeader.equals("Content-Length")) |=s3a5sl  
{ KK</5Aw9p  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); MzD0F#Y  
break; JB<4 m4-  
} Ji q[VeLe  
} .~J^`/o  
else ^h=kJR9  
break; PAkW[;GSDh  
}  7I|Mq  
} +F|[9o z  
catch(IOException e){e.printStackTrace ();} M.xEiHz  
catch(Exception e){e.printStackTrace ();} cqudF=q  
Hr$5B2'  
.U_=LV]C  
Utility.log(nFileLength); $hio (   
mz1g8M`@[D  
o1\8>Ew  
return nFileLength; &bQ^J%\  
} 9"S3AEI  
Xl;N= fc  
UB}mI0/w  
//保存下载信息(文件指针位置) u:ISwAp  
private void write_nPos() :%{7Q$Xv<  
{ Kl?1)u3^4  
try{ ikQ2x]Sp  
output = new DataOutputStream(new FileOutputStream(tmpFile)); rNc>1}DDS  
output.writeInt(nStartPos.length); *F0N'*  
for(int i=0;i<nStartPos.length;i++) iQF93:#  
{ B|v fkX2f  
// output.writeLong(nPos); n :P}K?lg  
output.writeLong(fileSplitterFetch.nStartPos); ?3#X5WT  
output.writeLong(fileSplitterFetch.nEndPos); f$|v  
} xh0!H| R  
output.close(); uypD`%pC  
} AI2CfH#:C  
catch(IOException e){e.printStackTrace ();} V 6F,X`7  
catch(Exception e){e.printStackTrace ();} TL>e[ PBO  
} _qV_(TpS+  
X}$S|1CjO  
Dg`W{oj  
//读取保存的下载信息(文件指针位置) [z\*Zg  
private void read_nPos() :[doYizk:  
{ lV8Mr6m  
try{ N5^:2ag  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +Q.[W`goV  
int nCount = input.readInt(); M:x(_Lu  
nStartPos = new long[nCount]; v;S JgZK  
nEndPos = new long[nCount]; 8J} J;Ga  
for(int i=0;i<nStartPos.length;i++) M4| L  
{ lgl/| ^ Uw  
nStartPos = input.readLong(); ;XT$rtuX  
nEndPos = input.readLong(); r_G`#Z_5F  
} !SnpesTn  
input.close(); 8Ex0[ e  
} bTj,5,8 i  
catch(IOException e){e.printStackTrace ();} eIJQ|p<v  
catch(Exception e){e.printStackTrace ();} vJ!t.Vou  
} R-ci?7dt3  
C}CX n X  
R##O9BSI8Z  
private void processErrorCode(int nErrorCode) y03l_E,  
{ HM/ q B^  
System.err.println("Error Code : " + nErrorCode); ;\h'A(  
} kDsUKO p  
#]rw@c  
fOfp.`n  
//停止文件下载 FwyPmtBj  
public void siteStop() ]l`DR4 =  
{ 2bqwnRT}  
bStop = true; VrpY BU  
for(int i=0;i<nStartPos.length;i++) BtspnVB ez  
fileSplitterFetch.splitterStop(); q6q= ,<T%S  
7 UR)4dYA  
@:}z\qBM  
} piU4%EO  
} ,M9'S;&^  
//负责部分文件的抓取 I/'>Bn+  
**FileSplitterFetch.java R0Qp*&AL  
*/ q_!3<.sf  
package NetFox; >a,w8^7  
|$Td-M^)  
QeGU]WU{  
import java.io.*; 1z)+P1nH]  
import java.net.*; {z w#My   
gCmGFQE-f  
Y#\e~>K  
public class FileSplitterFetch extends Thread { bbz86]AhY  
OnG?@sW+4!  
p?Y1^/   
String sURL; //File URL 3'8~H]<W  
long nStartPos; //File Snippet Start Position 1!~9%=%  
long nEndPos; //File Snippet End Position |nD`0Rbw  
int nThreadID; //Thread's ID IySlu^a  
boolean bDownOver = false; //Downing is over }G]]0Oi2  
boolean bStop = false; //Stop identical # aC}\  
FileAccessI fileAccessI = null; //File Access interface yY}`G-)g~*  
1UOFTI2S|  
Gb"PMai  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U9Sp$$L  
{ dG1qrh9_-  
this.sURL = sURL; Rc u/ @j{O  
this.nStartPos = nStart; \!_ >ul  
this.nEndPos = nEnd; MD%86m{Sg=  
nThreadID = id; Xs4`bbap  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -50|r;a  
} nF=h|rN  
&`@K/Nf$9  
U@H SU%H  
public void run() 'i}Q R~pe  
{ [xHK^JP 8F  
while(nStartPos < nEndPos && !bStop) Q WOd&=:  
{ G*ecM`Bl  
Yt&^ i(  
DwoO([&I  
try{ AtSEKpKc  
URL url = new URL(sURL); ^s^X nQhE  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nfc&.(6x<  
httpConnection.setRequestProperty("User-Agent","NetFox"); y8\44WKW  
String sProperty = "bytes="+nStartPos+"-"; 5WEF^1  
httpConnection.setRequestProperty("RANGE",sProperty); HH^eEh4g  
Utility.log(sProperty); %N2=:;f  
Hg<]5  
^;L;/I[-  
InputStream input = httpConnection.getInputStream(); \MnlRBUM,  
//logResponseHead(httpConnection); JD.WH|sZ5  
?>2k>~xlQ  
|@Bl?Bs+  
byte[] b = new byte[1024]; (%tKGeb  
int nRead; t'^/}=c-  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop)  1D6iJ  
{ Z O&5C6qa  
nStartPos += fileAccessI.write(b,0,nRead); =YR/|9(  
//if(nThreadID == 1) `U)~fu/\2M  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }yUZ(k#  
} b*7OIN5h  
<Dl7|M  
nT:ZSJWM  
Utility.log("Thread " + nThreadID + " is over!"); O0e6I&u :  
bDownOver = true; <`BUk< uf#  
//nPos = fileAccessI.write (b,0,nRead); KATt9ox@  
} TwY]c<t  
catch(Exception e){e.printStackTrace ();} 4~D?F'o  
} d&F8nBIM5  
} ~i(X{ ^,3  
~qs 97'  
4\>Cnc{  
//打印回应的头信息 Q 1g@FsW&U  
public void logResponseHead(HttpURLConnection con) M*|x,K=U  
{ WJ8i,7  
for(int i=1;;i++) VGkwrS;+I  
{ t=5 K#SX}  
String header=con.getHeaderFieldKey(i); 7&E3d P  
if(header!=null) sT|8a  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); IF<pT)  
Utility.log(header+" : "+con.getHeaderField(header)); Dr&2q X!  
else +g%kr~w=  
break; Pr9$( 6MX  
} Iell`;  
} K%O%#Kk  
_uID3N%  
*zJ}=%)f  
public void splitterStop() e+j7dmGa  
{ .hXxh)F  
bStop = true; Q YPsqkF*  
} YhRES]^  
|X0h-kX4  
UO>ADRs}  
} m!V ?xGKJ  
`$7. (.#s  
uPhFBD7  
/* :>]= YE  
**FileAccess.java 4u0=/pfi[  
*//文件访问(定位,写) gh#9<  
package NetFox; Pd6p)zj  
import java.io.*; WL:CBE#  
pO[ @2tF  
nD6NLV%2x  
public class FileAccessI implements Serializable{ wknX\,`Q  
S{&,I2aO  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `{#0C-  
RandomAccessFile oSavedFile; zuwlVn  
long nPos; F|Pf-.r`t  
)%I2#Q"Nt-  
[LbUlNq^B@  
public FileAccessI() throws IOException |wZcVct~  
{ Z_Qs^e$  
this("",0); FWNWOU  
} 07`hQn)Gc  
&Ba` 3V\M  
f%<kcM2  
public FileAccessI(String sName,long nPos) throws IOException PRg^E4  
{ &'Pwz  
oSavedFile = new RandomAccessFile(sName,"rw"); 2r4owB?  
this.nPos = nPos; h\k@7wgu  
oSavedFile.seek(nPos); c 2t<WRG  
} @9Rg g9r  
F jsnFX;  
tJ;<=.n  
public synchronized int write(byte[] b,int nStart,int nLen) WBvh<wTw;  
{ ge %ytrst  
int n = -1; /}t>o* x  
try{ (e.?). e  
oSavedFile.write(b,nStart,nLen); &@NTedg!  
n = nLen; aNs~Uad1U  
} }8`W%_Yk  
catch(IOException e) [uqe|< :  
{ Q8OA{EUtq  
e.printStackTrace (); l];w,(u{  
} :sDE 'o  
9$U@h7|Q`  
Jr+~'  
return n; >>22:JI`  
} kV9S+ME  
: p %G+q2  
Y>W$n9d&G2  
} 8` ~M$5!  
Jas=D  
FOz~iS\  
/* u_ou,RF  
**SiteInfoBean.java S{wR Z|8U  
*/ #SyF-QZ[1  
package NetFox; S5'ZKk  
^C$Oht,cU  
}81eef4$S  
public class SiteInfoBean { wiHGTaR  
8$9Q=M  
M uz+j.0  
private String sSiteURL; //Site's URL @/jLN  
private String sFilePath; //Saved File's Path nIc:<w]  
private String sFileName; //Saved File's Name X)6}<A  
private int nSplitter; //Count of Splited Downloading File '9d<vW g  
[Ume^  
ML eo3  
public SiteInfoBean() g2)jd[GM  
{//nSplitter的缺省值为5 vz$-KT4e^  
//default value of nSplitter is 5 YvA@I|..~  
this("","","",5); ]:H((rk  
} l}w9c`f  
RgTm^?Ex  
o^ Z/~N  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q5Yy \M  
{ !'m MGxkEb  
sSiteURL= sURL; SUGB)vEa  
sFilePath = sPath; 6WI-ZEVp&  
sFileName = sName; Qg9*mlm`  
this.nSplitter = nSpiltter; (h&XtFul}  
#WE"nh9f|z  
8d4:8}  
} 4sJM!9eb[  
-o: if F|  
;zq3>A  
public String getSSiteURL() itotn!Wb`  
{ 3jR>   
return sSiteURL; JdYmUM|K/c  
} dOG]Yjc  
pX 4:WV  
,EsPm'`?A/  
public void setSSiteURL(String value) b{+7sl  
{ U -h'a: K  
sSiteURL = value; |aWeo.;c  
} *aem5 E`c  
^lw0} i  
3jeB\  
public String getSFilePath() ]\TYVv)  
{ KH=4A-e,0  
return sFilePath; hKx*V"7/#\  
} _.}1 Y,Q  
:2v^pg|  
c qWX*&2_  
public void setSFilePath(String value) '>"riEk  
{ mHj3ItXUu  
sFilePath = value; 6 (M^`&fl  
}  <xn96|$  
8,VX%CS#q  
xJcM1>cT>  
public String getSFileName() yiT)m]E d  
{ yW@0Q:  
return sFileName; 5Yxs_t4  
} &PE/\_xD_  
NI<;Lm  
&<Iyb}tA?  
public void setSFileName(String value) `qXCY^BH2  
{ 8?yRa{'"  
sFileName = value; WSi`KNX  
} :NCY6? [Dz  
s8O.yL  
OCX>LK!K  
public int getNSplitter() J`I^F:y*  
{ !Py SYY  
return nSplitter; LvM;ZfAEv  
} 0aWy!d  
BI|BfO%F$j  
1K&_t  
public void setNSplitter(int nCount) N'5AU (  
{ @gc|Z]CV  
nSplitter = nCount; j Z6]G{  
} MJyz0.9c  
} {?+dVLa^;  
- WEEnwZ  
Q`0 k=<  
/* wO-](3A-8P  
**Utility.java {p90   
*/ *X%dg$VcV  
package NetFox; H Z)an  
_x'?igy  
U@'F9UB`  
public class Utility { HxE`"/~.7k  
i!nPiac  
Le?yzf  
public Utility() SWq5=h  
{ s.uw,x  
dv7IHUFf  
l<DpcLX  
} ?7eD< |  
;)c 4  
//线程睡眠 L_~vPp  
public static void sleep(int nSecond) ' K\ $B_  
{ d*cAm$  
try{ ZC!GKW P2  
Thread.sleep(nSecond); <+r<3ZBA  
} g~/@`Z2Y  
catch(Exception e) $D%[}[2  
{ 12olVTuw  
e.printStackTrace (); s*3p*zf  
} rn8#nQ>QZ%  
} Nn:>c<[  
:~PzTUz  
//日志 cD5^mxd%  
public static void log(String sMsg) |to|kU  
{ I_aS C4  
System.err.println(sMsg); gX'nFGqud  
} \v,m r|  
%=PGvu  
f 8AgTw,K8  
public static void log(int sMsg) lYq/ n&@_1  
{ lk[BS*  
System.err.println(sMsg); s9\HjK*+  
} n7$2 1*,  
} No(p:Snbo  
q33Z.3R  
]!mC5Ea  
/* +<TnE+>j  
**TestMethod.java cy%S5Rz  
*/ }b$W+/M\  
package NetFox; F,)\\$=,  
U%qE=u-  
3B^`xnV  
public class TestMethod { M[}aQWT$v  
^DaP^<V  
I<}<!.Bc!  
public TestMethod() ?E2$  
{ ///xx/weblogic60b2_win.exe F?jFFw im  
try{ h+"UK=  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /t $J<bU  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ch-.+p3  
SiteFileFetch fileFetch = new SiteFileFetch(bean); qVe&nXo  
fileFetch.start(); MEled:i  
} o 00(\ -eb  
catch(Exception e){e.printStackTrace ();} R>CIEL  
84|oqwZO  
\[CPI`yQe  
} C\RJ){dk  
'0MH-M  
WKDa]({k%  
public static void main(String[] args) ,T<q"d7-#  
{ #ts;s\!  
new TestMethod(); Q[Xh{B  
} _ !r]**  
} GyP.;$NHa[  
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