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http断点续传简单实现(java)

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/* Z5"!0B^ j  
**SiteFileFetch.java Y*]l|)a6_]  
*/ xc:`}4  
package NetFox; CnM+HN30o  
import java.io.*; 5<'n  
import java.net.*; Lf$Q %eM0  
d=Rk\F'^J  
'vqj5YTj  
public class SiteFileFetch extends Thread { g~bf!  
'LtgA|c=  
9q@ z[+X  
SiteInfoBean siteInfoBean = null; //文件信息Bean z7NGpA(  
long[] nStartPos; //开始位置 :)^# xE(  
long[] nEndPos; //结束位置 5`OK-  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ?NL&x  
long nFileLength; //文件长度 [R@q]S/  
boolean bFirst = true; //是否第一次取文件 ="'rH.n #  
boolean bStop = false; //停止标志 muqfSF  
File tmpFile; //文件下载的临时信息 o O{|C&A  
DataOutputStream output; //输出到文件的输出流 u&l>cJ'  
"-~D! {rS  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 4iL.4Uj{N  
public SiteFileFetch(SiteInfoBean bean) throws IOException %^Q@*+{:f  
{ 5JXzfc9rL  
siteInfoBean = bean; pw(U< )  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ,=q7}5o Y  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); q\z=z$VR  
if(tmpFile.exists ()) ?,+C!R?  
{ |}]JWsuB  
bFirst = false; .MzP}8^  
read_nPos(); iuH8g  
} Z!s>AgH9u  
else ~#N.!e4  
{ Qzs\|KS  
nStartPos = new long[bean.getNSplitter()]; mZ& \3m=  
nEndPos = new long[bean.getNSplitter()]; cx1WGbZ  
} R4Gg|Bh  
mBD!:V'  
RT_Pd\(qD  
Y9I #Q  
} 709Uv5  
sg9x?Bx9  
Hc_hO  
public void run() #:Sy`G6!?  
{ twJ|Jmd  
//获得文件长度 r-\T}e2Gz  
//分割文件 oE|u;o  
//实例FileSplitterFetch 8wH41v67F  
//启动FileSplitterFetch线程 q!9v}R3(  
//等待子线程返回 f@xfb ie !  
try{ Ep,0Z*j  
if(bFirst) DbNi;m  
{ 71n uTE%!  
nFileLength = getFileSize(); {pQ@0 b  
if(nFileLength == -1) lJz?QI1  
{ Fh!!T%5>C  
System.err.println("File Length is not known!"); Ymk4Cu.s  
} @y~BYiKs  
else if(nFileLength == -2) 61Iy{-/ZV  
{ ~jRk10T(B  
System.err.println("File is not access!"); n[cyK$"  
} f)s_e  
else Ow .)h(y/  
{ +<9q]V  
for(int i=0;i<nStartPos.length;i++) U~B}vt  
{ 5 1CU@1Ie  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 2Ws/0c  
} ~|B!. +  
for(int i=0;i<nEndPos.length-1;i++) yM#trqv5  
{ O^="T^J  
nEndPos = nStartPos[i+1];  =R24 h  
} mj2sbRiSR=  
nEndPos[nEndPos.length-1] = nFileLength; &G+:t)|S  
} k0DX|O8mXV  
} Lb2/ Te*  
j0e1CSE  
xkz`is77Y@  
//启动子线程 mw=keY9]  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Jz_`dLL^ w  
for(int i=0;i<nStartPos.length;i++) V ;M'd@  
{ YccD ^w[`B  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lN::veD  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 54&&=NVs|  
nStartPos,nEndPos,i); ^eqq|(<K  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !2]G.|5/A  
fileSplitterFetch.start(); k5GJrK+  
} rEZMX2  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =ThacZHb8  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pexg"328  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mv9@Az9  
nEndPos = " + nFileLength); =)XC"kU p  
// fileSplitterFetch[nPos.length-1].start(); "V7&@3  
N6S}u@{J~N  
k%ckV`y  
//等待子线程结束 +P 9h%/Yk  
//int count = 0; I!,FxOM|$  
//是否结束while循环 0SWec7G  
boolean breakWhile = false; :mz6*0qW  
X9n},}bJ"  
t{ScK%S6  
while(!bStop) W-@}q}A  
{ 0N*~"j;r#M  
write_nPos(); {3=]cLtt  
Utility.sleep(500); :+\B|*T2.L  
breakWhile = true; n8>( m,  
PaYsn *{})  
Ycve[31BDd  
for(int i=0;i<nStartPos.length;i++) >`c-Fqk  
{ f\gN+4)  
if(!fileSplitterFetch.bDownOver) M2e_)f:  
{ p_2-(n@  
breakWhile = false; {kgV3 [%>  
break; ^iaG>rvA  
} ?Dk&5d^d  
} 8DP] C9  
if(breakWhile) s@vHU4  
break; oefhJM!y  
!r*Ogv[  
p$ %D  
//count++; A~Ov(  
//if(count>4) ?4,e?S6,[  
// siteStop(); Dy_Za.N2  
} 6{p] cr  
qXJBLIG  
X!%CYmIRb  
System.err.println("文件下载结束!"); I+]q;dF;  
} w8df-]r  
catch(Exception e){e.printStackTrace ();} "eiZZSz  
} ]ozZW:  
~ g\GC  
E/</  
//获得文件长度 \]eB(&nq  
public long getFileSize() ?|t9@r  
{ .Bu?=+O~  
int nFileLength = -1; H_<X\(  
try{ z\fmwI  
URL url = new URL(siteInfoBean.getSSiteURL()); b+.P4+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nDvj*lZF  
httpConnection.setRequestProperty("User-Agent","NetFox"); q;p:)Q"  
[80L|?, *  
ny:4L{)  
int responseCode=httpConnection.getResponseCode(); t_PAXj  
if(responseCode>=400) }x^q?;7xW  
{ ,s*-2Sz  
processErrorCode(responseCode); ersddb^J]  
return -2; //-2 represent access is error i+)9ItZr  
} 8MH ZWi  
BuE=(v2}  
i,DnXgmz@  
String sHeader; 9K\A4F}  
H53dy*wb$  
JlZU31Xws  
for(int i=1;;i++) n-P)X<\  
{ #3l&N4/  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o+o'!)  
//Utility.log(in.readLine()); `J%iFm/5*  
sHeader=httpConnection.getHeaderFieldKey(i); b'Scoa7@'  
if(sHeader!=null) )c:i 'L  
{ gn>qd6P  
if(sHeader.equals("Content-Length")) Ps@a@d"83  
{ 2nL [P#r  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &> Myf@  
break; xU4,Rcgo  
} p<w2e  
} p_x@FA(  
else 3_:J`xX(4  
break; biJ"@dm 4  
} w^e5"og]  
} dD Qx[  
catch(IOException e){e.printStackTrace ();} SLyeonM-C  
catch(Exception e){e.printStackTrace ();} }0& @J'<  
/1F5khN  
i/j DwA  
Utility.log(nFileLength); =i_ s#v[Y  
8CR b6  
]m _<lRye  
return nFileLength; K+=cNC4B  
} r &<sSE;5  
5C}1iZEJ  
noali96J  
//保存下载信息(文件指针位置) +j*hbG=  
private void write_nPos() llbf(!  
{ +K6j p  
try{ ^EK]z8;|  
output = new DataOutputStream(new FileOutputStream(tmpFile)); hG~TqH^} B  
output.writeInt(nStartPos.length); A4lW8&rHI  
for(int i=0;i<nStartPos.length;i++) oa4{s&db-  
{ Y8 c#"vm(  
// output.writeLong(nPos); %r1NRg8  
output.writeLong(fileSplitterFetch.nStartPos); UMcQqV+vT  
output.writeLong(fileSplitterFetch.nEndPos); >l<`)4*H  
} %XX(x'^4  
output.close(); m&o6j>C  
} 0X.(BRI~6p  
catch(IOException e){e.printStackTrace ();} (!^i6z0Sp  
catch(Exception e){e.printStackTrace ();} - '<K_e;  
} :gD=F&V  
avJ%J"j8z  
,".1![b  
//读取保存的下载信息(文件指针位置) b4 Y<  
private void read_nPos() %25GplMT  
{ X+0+ }S  
try{ 2P`Z >_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 36 &ghx  
int nCount = input.readInt(); Bri yy  
nStartPos = new long[nCount]; uq.!{3)8  
nEndPos = new long[nCount];  I&m C  
for(int i=0;i<nStartPos.length;i++) }:04bIaV  
{ sbeS9vE  
nStartPos = input.readLong(); 25 NTtj:X  
nEndPos = input.readLong(); {WYJQKs8  
} ';>]7oT`  
input.close(); & xAwk-{W  
} l2Gtw*i_I  
catch(IOException e){e.printStackTrace ();} 0bl?dOV{  
catch(Exception e){e.printStackTrace ();} %< ^IAMkp  
} +4*3aWf`  
#N?VbDK9_  
|\# ~  
private void processErrorCode(int nErrorCode) kYW>o}J|  
{ _l{`lQ}  
System.err.println("Error Code : " + nErrorCode); "!g}Q*   
} bfE4.YF  
'<Fr}Cn  
|c<h& p  
//停止文件下载 Whd\Ub8(  
public void siteStop() [3@Pu.-I+M  
{ Y8%bk2  
bStop = true; 5YZh e4R  
for(int i=0;i<nStartPos.length;i++) [C>>j;q%  
fileSplitterFetch.splitterStop(); R^hlfKnt  
~/QzL.S;p  
JPmW0wM  
} h"j{B  
} >*EcX3  
//负责部分文件的抓取 Tf` ~=fg%  
**FileSplitterFetch.java ]@Q14   
*/ Wa ,  #  
package NetFox; e)O6k7U$  
!x[ +rf  
iGM-#{5  
import java.io.*; st~f}w@  
import java.net.*; *Z Aue.  
iYR8sg[' #  
j$BM$q/c  
public class FileSplitterFetch extends Thread { H>k=V<  
iN<Tn8-YH6  
flnoK%wi  
String sURL; //File URL UfXqcyY(  
long nStartPos; //File Snippet Start Position YaDr6)  
long nEndPos; //File Snippet End Position  ^~?VD  
int nThreadID; //Thread's ID A6= Um%T  
boolean bDownOver = false; //Downing is over 5) nm6sf  
boolean bStop = false; //Stop identical [T.kwQf4$  
FileAccessI fileAccessI = null; //File Access interface #X`j#"Ov2(  
^|(F|Z  
?=-18@:.ss  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y}Y2 Vx  
{ eE+zL ~CE  
this.sURL = sURL; :k#Y|(  
this.nStartPos = nStart; ,a_\o&V  
this.nEndPos = nEnd; X*/j na"*  
nThreadID = id; &dH/V-te  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KYZ/b8C  
} C5$1K'X@  
eE '\h  
,)[u<&  
public void run() $b QD{ {  
{ mY+J ju1  
while(nStartPos < nEndPos && !bStop) /z.Y<xOc  
{ /q0[T{Wz$  
#"|</*% >  
 mR)Xq=  
try{ AQw1,tGV  
URL url = new URL(sURL); .i) H1sD  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z1{kZk  
httpConnection.setRequestProperty("User-Agent","NetFox"); qH1[Bs Ox  
String sProperty = "bytes="+nStartPos+"-"; ]6bh#N;.  
httpConnection.setRequestProperty("RANGE",sProperty); N7v7b<6  
Utility.log(sProperty); `A_CLVE  
9nN$%(EO5;  
J^m#984  
InputStream input = httpConnection.getInputStream(); -~n^?0  
//logResponseHead(httpConnection); ~oWCTj-  
["TUSf]  
j^-E,YMC  
byte[] b = new byte[1024]; M_lQ^7/  
int nRead; !<BJg3  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ">_<L.,I  
{ ND $m|V-C  
nStartPos += fileAccessI.write(b,0,nRead); FrT.<3  
//if(nThreadID == 1) +m8CN(c  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |Ii[WfFA|J  
} a~ sU  
a|?&  
(&t741DN|  
Utility.log("Thread " + nThreadID + " is over!"); o b;]  
bDownOver = true; s\O4D*8  
//nPos = fileAccessI.write (b,0,nRead); Jmg<mjq/G  
} *'[8FZ|dQ  
catch(Exception e){e.printStackTrace ();} <q\OREMsq  
} HEh,Cf7`'  
} tQ~vLPi$  
rH Y SS0*3  
r:;nv D  
//打印回应的头信息 5^lFksZ  
public void logResponseHead(HttpURLConnection con) l Oxz&m  
{ J,q6  
for(int i=1;;i++) @N+ }cej  
{ <5@VFRjc  
String header=con.getHeaderFieldKey(i); y#tuwzE  
if(header!=null) E&>3{uZI  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^EtBo7^t  
Utility.log(header+" : "+con.getHeaderField(header)); 8[v9|r  
else (dvsGYT|.  
break; 0n dk=V  
} b-!+Q)  
} <9f;\+zA  
@}K|/  
>%6a$r~@  
public void splitterStop() /Uxp5 b h  
{ +;#z"m]  
bStop = true; z3Id8G&>  
} Z01BzIsR  
2bv/ -^  
<DeC^[-P  
} l7T@<V  
lKVV*RR}  
ce56$L8[  
/* [KcF0%a  
**FileAccess.java ;r8< Ed  
*//文件访问(定位,写) zjE|UK{  
package NetFox; +4 W6{`  
import java.io.*;  eeMeV>  
#3~hF)u&/  
PP*',D3  
public class FileAccessI implements Serializable{ fvE:'( #?  
1ze\ U>  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3a Y^6&  
RandomAccessFile oSavedFile; 6lAHB*`  
long nPos; #r,LV}*qg  
n9H4~[JiC  
{,X}Btnwp  
public FileAccessI() throws IOException c3__=$)'kP  
{ [ !<  
this("",0); XM#xxf* Y  
} Ht,+KbB  
q?##S'  
xg.o7-^M  
public FileAccessI(String sName,long nPos) throws IOException {t%Jc~p{  
{ 5 (cgHr"  
oSavedFile = new RandomAccessFile(sName,"rw"); 2kSN<jMr  
this.nPos = nPos; OD8{ /7  
oSavedFile.seek(nPos); $ S'~UbmYU  
} qdNt2SO  
DG-XX.:z  
I xk+y?  
public synchronized int write(byte[] b,int nStart,int nLen) Ri<'apl  
{ zL@FN sYVM  
int n = -1; PdD,~N#  
try{ ))xP]Muv  
oSavedFile.write(b,nStart,nLen); $6DA<v^=z  
n = nLen; TbQ5  
} eqQ=HT7J  
catch(IOException e) _ `~\zzUZ  
{ L ]Y6/Q   
e.printStackTrace (); %8c2d  
} ,!>1A;~wT  
7^FJ+gN8b  
o>jM4sk$  
return n; :~wU/dEEiz  
} Wi2Tg^  
I3hN7  
Iw[7;B5v  
} xcM*D3  
]t)#,'$^[W  
7GDrH/yK  
/* vE{L`,\ q  
**SiteInfoBean.java _eZ*_H,\  
*/ L_O*?aaZ  
package NetFox; GyQ9we~  
|w+N(wcJ  
=-%10lOI  
public class SiteInfoBean { U#6<80Ke  
yFY:D2  
M]7>Ar'zsG  
private String sSiteURL; //Site's URL PHR:BiMZ  
private String sFilePath; //Saved File's Path % 3Tz%>n  
private String sFileName; //Saved File's Name +Es3iE @  
private int nSplitter; //Count of Splited Downloading File Rg<y8~|'}  
N:0/8jmmO  
G9z Q{E  
public SiteInfoBean() =r+u!~%@''  
{//nSplitter的缺省值为5 ?)Z~H,Q(z  
//default value of nSplitter is 5 {~16j"  
this("","","",5); v;el= D  
} CY)Wuv ^  
?F*gFW_k  
E8jdQS|i  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )Be}Ev#)Zx  
{ %&Z!-k(  
sSiteURL= sURL; U?>P6p  
sFilePath = sPath; VyCBJK  
sFileName = sName; ; z:}OD  
this.nSplitter = nSpiltter; -#3B>VY  
\PU|<Ru.  
=4 &9!Z  
} fcr\XCG7U  
+q) ^pCC  
Cf<i"   
public String getSSiteURL() p8[Z/]p  
{ RNcHU  
return sSiteURL; }_3<Q\j  
} lj@c"Yrk  
`P)atQ  
q3T'rw%Eh  
public void setSSiteURL(String value) 1`5d~>fV  
{ Th`IpxV  
sSiteURL = value; \W( C=e  
} a5?Rj~h!<  
x V~`sqf  
pUYa1=  
public String getSFilePath() wR@fB  
{ 4B-v\3Ff  
return sFilePath; wCkhE,#-_  
} ,X+mXtg.  
fJd!;ur)0  
cDxjD5E  
public void setSFilePath(String value) w \i#  
{ -1:yqF.x  
sFilePath = value; yZJR7+  
} (orO=gST-/  
|Rk$u  
z.itVQs$I  
public String getSFileName() 86(8p_&zC  
{ _+ z5~6>  
return sFileName; {bB;TO<b`  
} 4#H~g @  
ghq#-N/t  
ye Q6\yi  
public void setSFileName(String value) ptXCM[Z+  
{ u'"VbW3u n  
sFileName = value; lqPzDdC^>  
} tm27J8wPzV  
}$-;P=k  
871taL=  
public int getNSplitter()  p]z *  
{ ! Ff/RRo  
return nSplitter; 0_7A <   
} 5"1kfB3v  
cnfjO g'\{  
C^>txui8  
public void setNSplitter(int nCount) 5AV5`<r.  
{ <C0~7]XO  
nSplitter = nCount; 5e^t;  
} (gd+-o4  
} ]mEY/)~7  
S+LE ASOr  
[0v`E5  
/* vvEr}G  
**Utility.java gc|?$aE  
*/ ^(5Up=.EA  
package NetFox; 'urn5[i  
CT1)tRN  
\bJ,8J1C  
public class Utility { 34lt?6%j  
~s_n\r&23  
)@"iWQ 3K  
public Utility() ":t'} Eg=6  
{ r=8(n<;Co  
d^5OB8t  
pa1.+~)  
} ")%)e;V3  
R7xKVS_MP  
//线程睡眠 }*4K{<02  
public static void sleep(int nSecond) # fvt:iE  
{ \nQV{J  
try{ {Vy2uow0  
Thread.sleep(nSecond); .QRa{l_)  
} H=2sT+Sp  
catch(Exception e) Y](kMNUSg  
{ j*uc$hC"  
e.printStackTrace (); 7g'jg7  
} Jb. V4  
} 7A!E~/nSC  
MXy~kb&  
//日志 9d7`R'  
public static void log(String sMsg) JO*}\Es  
{ n)]]g3y2  
System.err.println(sMsg); yb)!jLnH  
} ZH]n&%@j  
19.+"H  
_ ^5w f  
public static void log(int sMsg) /yRP>CX~  
{ s d -5AE  
System.err.println(sMsg); |3tq.JU  
} *AEN  
} r*e<`Is  
}bwH(OOS  
.Sz<%d7XIQ  
/* N@Ie VF  
**TestMethod.java g=8}G$su{%  
*/ 9 U6cM-p?  
package NetFox; !3]}3jZ.  
dEz7 @T  
xx^7  
public class TestMethod { XJ\ j0  
Mp8BilH-T  
zqd_^  
public TestMethod() nYfZ[Q>v  
{ ///xx/weblogic60b2_win.exe ;xp^F KP  
try{ K,pQ11J  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B2}|b^'I  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 58T<~u7  
SiteFileFetch fileFetch = new SiteFileFetch(bean); )vO?d~x|  
fileFetch.start(); FQc8j:'  
} -Re4G78%  
catch(Exception e){e.printStackTrace ();} }Xn5M&>?  
Gag=GHG  
PP~rn fE  
} V=He_9B  
/iNa'W5\  
5 8-e^.  
public static void main(String[] args) v[@c*wo  
{ YIt& >  
new TestMethod(); L9Z;:``p  
} n,HE0Zn]Y_  
} X{n- N5*  
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