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http断点续传简单实现(java)

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/* gL"}53A  
**SiteFileFetch.java PoJyWC  
*/ %`1vIr(7  
package NetFox; =)YYx8gR  
import java.io.*; 'lk74qU$  
import java.net.*; UK>=y_FYO  
uq%3;#[0  
Nj_sU0Dt  
public class SiteFileFetch extends Thread { D,j5k3< #  
@>IjfrjV  
,rI |+  
SiteInfoBean siteInfoBean = null; //文件信息Bean FBAC9}V"  
long[] nStartPos; //开始位置 } XU:DE  
long[] nEndPos; //结束位置 1$VI\}  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 E@6r{uZ#  
long nFileLength; //文件长度 T:">,* |  
boolean bFirst = true; //是否第一次取文件 Iq]6]  
boolean bStop = false; //停止标志 mtQ{6u  
File tmpFile; //文件下载的临时信息 $jm<' 4  
DataOutputStream output; //输出到文件的输出流 \,gZNe&Vv  
-!>ZATL<B  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) bMZn7c  
public SiteFileFetch(SiteInfoBean bean) throws IOException b DS1'Ce  
{ 8@KFln )[  
siteInfoBean = bean; SWsv,  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Mgs|*u-5  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); V8$bPVps  
if(tmpFile.exists ()) u2B W]T]  
{ ,M&0<k\  
bFirst = false; Ti|++oC/&  
read_nPos(); h&M RQno  
} J<#`IaV  
else {U '&9_y  
{ %Dls36F  
nStartPos = new long[bean.getNSplitter()]; "ue$DyN  
nEndPos = new long[bean.getNSplitter()]; doO Ap9%  
} <lmJa#  
So *Wk "  
{dx /p-Tv  
0o$HC86w  
} wv.Ul rpx.  
:2)1vQH0L  
6a?$=y  
public void run() Gi2ad+QH-  
{ H\+c'$  
//获得文件长度 5%+bWI{w  
//分割文件 T5jG IIa  
//实例FileSplitterFetch *tM7>  
//启动FileSplitterFetch线程 {&E Z>r-  
//等待子线程返回 I/V )z9  
try{ 9>&tMq  
if(bFirst) )g:,_1s)|  
{ +%qSB9_>N{  
nFileLength = getFileSize(); QiE<[QP{g  
if(nFileLength == -1) Gz|%;  
{ x~9z`d{!  
System.err.println("File Length is not known!"); ^GrkIh0nL  
} E'^]zW=9  
else if(nFileLength == -2) #O9*$eMw  
{ k\c &2T]W  
System.err.println("File is not access!"); +#uNQ`1v  
} )*K<;WI WH  
else *Iwk47J ;a  
{ EPe]-C`  
for(int i=0;i<nStartPos.length;i++) NVc! g  
{ -)O kG#J@  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); B.mbKntK)R  
} ]6B mCh  
for(int i=0;i<nEndPos.length-1;i++) *Qg5Z   
{ ZE8/ m")  
nEndPos = nStartPos[i+1]; f;Bfh3  
} .eabtGO,  
nEndPos[nEndPos.length-1] = nFileLength; R=amKLD?  
} Z0ncN])  
} ,M@m4bx  
_:g GD8  
S $_Y/x  
//启动子线程 <duBwkiG  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /iTUex7T  
for(int i=0;i<nStartPos.length;i++) >1r[]&8  
{ B221}t  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |)?aH2IL  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hX8gV~E=y  
nStartPos,nEndPos,i); 1t[;`iZ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fATA%eA8;  
fileSplitterFetch.start(); C^,4`OI  
} &V#zkW  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {yHB2=nI  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gR;8ht(pd(  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uspkn1-  
nEndPos = " + nFileLength); ;c X^8;F0  
// fileSplitterFetch[nPos.length-1].start(); Sj0 ucnuHi  
<E[HlL  
 ^%5~ ;  
//等待子线程结束 ;5D @kS^  
//int count = 0; i.&Kpw9;m  
//是否结束while循环 U1>  
boolean breakWhile = false; O2q=gYX>\  
9iGE`1N%E  
Ld\LKwo  
while(!bStop) 5 dfe@$  
{ N[,VSO&  
write_nPos(); {1Ju} =69  
Utility.sleep(500); 1 ;\]D9i  
breakWhile = true; bB;~,W&E1  
Q7 uAf3  
*>aZc::  
for(int i=0;i<nStartPos.length;i++) +~w?Xw,  
{ <V$Y6(uMs  
if(!fileSplitterFetch.bDownOver) O&#S4]Y   
{ `;5VH]V  
breakWhile = false; rL%]S&M9  
break; >@)*S n9"  
} {d 1N&  
} QiTR-M2C!  
if(breakWhile) FJa[ToZ4+  
break; U] V3DDN  
I|KY+k> /  
8h&oSOkQk,  
//count++; `Di ^6UK(  
//if(count>4) fiE>H~  
// siteStop(); nDHHYp  
} c~gNH%1XN  
5JBB+g  
vzY'+9q1.  
System.err.println("文件下载结束!"); ]aC ':55(  
} ,DQGv_  
catch(Exception e){e.printStackTrace ();} L$Hx?^3  
} z(g%ue\  
a=J@y K  
iK5]y+@8  
//获得文件长度 UF&0 & `@  
public long getFileSize() Vs_\ykO  
{ r6d0x  
int nFileLength = -1; MzEm*`<  
try{ HGO#e  
URL url = new URL(siteInfoBean.getSSiteURL()); !,cQ'*<W8-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /d0Q>v.g  
httpConnection.setRequestProperty("User-Agent","NetFox"); f >mhFy  
,f8}q]FTA  
4Qa@`  
int responseCode=httpConnection.getResponseCode(); )XLj[6j0  
if(responseCode>=400) >Z#uFt0<Pm  
{ N]1V1c$G*  
processErrorCode(responseCode); 1YOg1 n+k  
return -2; //-2 represent access is error Gw ~{V  
} Qg'c?[~W@  
dtB[m^$  
==%`e/~Y  
String sHeader; On#;)35M  
b#D9eJhS  
z.eJEK  
for(int i=1;;i++) 3R5K}ZBi%  
{ *j|/2+pq  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F(Lb8\to\M  
//Utility.log(in.readLine()); 5;IT64&]  
sHeader=httpConnection.getHeaderFieldKey(i); BZovtm3 E  
if(sHeader!=null) k$ZRZ{ E+  
{ )Rjb/3*!  
if(sHeader.equals("Content-Length")) 99<4t$KH  
{ E% <w5d.lq  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v<L=!-b^  
break; nd.57@*M  
} ^I]LoG:  
} P@qMJ}<j  
else 7~_{.f  
break; v1 LKU  
} `wNm%*g  
} OENzG~  
catch(IOException e){e.printStackTrace ();} Y\.-v\uJu  
catch(Exception e){e.printStackTrace ();} Q;4}gUmI$  
FoE|Js  
xDR9_  
Utility.log(nFileLength); :]vA 2  
iV5}U2Vh  
Rw{$L~\  
return nFileLength; IikG /8lP  
} "hL9f=w  
{DU"]c/S  
^#]c0  
//保存下载信息(文件指针位置) ?nQ_w0j  
private void write_nPos() _b>F#nD,'%  
{ *i@sUM?K  
try{ ,Z^Ca15z  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2zz,(RA  
output.writeInt(nStartPos.length); ? m&IF<b  
for(int i=0;i<nStartPos.length;i++) :.Y|I[\E%  
{ dVa!.q_3  
// output.writeLong(nPos); O/mR9[}  
output.writeLong(fileSplitterFetch.nStartPos); r]v&t  
output.writeLong(fileSplitterFetch.nEndPos); &=YSM.G  
} yH*hL0mO  
output.close(); :*^:T_U  
} Vzpt(_><  
catch(IOException e){e.printStackTrace ();} 59.$ULQVMY  
catch(Exception e){e.printStackTrace ();} X4a^m w\"  
} q(,cYu  
!{;[xXK4M  
! 0^;;'  
//读取保存的下载信息(文件指针位置) k^z0Lo|)'  
private void read_nPos() =4eUAeH {w  
{ #,G1R7  
try{ 1Q]Rd  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |+98h&U~  
int nCount = input.readInt(); Z.quh;  
nStartPos = new long[nCount]; _1ew(x2J  
nEndPos = new long[nCount]; 5UE409Gn'  
for(int i=0;i<nStartPos.length;i++) <$%ql'=  
{ 9z:K1  
nStartPos = input.readLong(); T .kyV|  
nEndPos = input.readLong(); kB o;h.[l  
} -LTKpN`[@  
input.close(); +=7:4LFOL  
} `ruNA>M  
catch(IOException e){e.printStackTrace ();} _3/ec]1  
catch(Exception e){e.printStackTrace ();} Jm4#V~w  
} 5k]XQxc6_  
[u`6^TycP  
f-4.WW2FN  
private void processErrorCode(int nErrorCode) JBz}|M D  
{ 9RH"d[%yc}  
System.err.println("Error Code : " + nErrorCode); %<ic%gt`#  
} v9=}S\=Cd  
s.VA!@F5  
$/+so;KD  
//停止文件下载 %#u.J  
public void siteStop() l;OYUq~F  
{ [>f]@>  
bStop = true; /prYSRn8  
for(int i=0;i<nStartPos.length;i++) Z0$] tS  
fileSplitterFetch.splitterStop(); Z0-ytODI I  
Vo\H<_=G  
>)NQH9'1  
} ~O{W;Cyh  
} \6o\+OQk  
//负责部分文件的抓取 3+ =I;nj  
**FileSplitterFetch.java YGp)Oy}:  
*/ /;Yy@oc  
package NetFox; `N}d}O8   
b0rX QMu  
\:Za[6  
import java.io.*; =LI:S|[4  
import java.net.*; | f\D>Y%)  
_1aGtX|W  
<J&7]6Z  
public class FileSplitterFetch extends Thread { =\Iu$2r`  
z<B CLP  
='}#`',  
String sURL; //File URL h d2'AlB  
long nStartPos; //File Snippet Start Position yzR=A%V8A  
long nEndPos; //File Snippet End Position %D`o  
int nThreadID; //Thread's ID yS!(Ap  
boolean bDownOver = false; //Downing is over 8O7Yv<  
boolean bStop = false; //Stop identical @E%DP9.I  
FileAccessI fileAccessI = null; //File Access interface L[y Pjw:0  
-R0/o7  
zT[6eZ8m  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &J$##B  
{ (u&`Ij9  
this.sURL = sURL; e4\dpvL  
this.nStartPos = nStart; W\8Ln>  
this.nEndPos = nEnd; Z(e ^iH  
nThreadID = id; ?qmp_2:WU  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jn JZ# =)  
} :U'Cor H  
e)@3m.  
X:EEPGE  
public void run() 7C7>y/uS  
{ Q9c)k{QZ  
while(nStartPos < nEndPos && !bStop) #H~_K}Ks  
{ O,s.D,S  
P|xG\3@Z  
F PR`tE  
try{ D."=k{r.  
URL url = new URL(sURL); %d2!\x%bG  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BI/&dKM  
httpConnection.setRequestProperty("User-Agent","NetFox"); W2]TRO  
String sProperty = "bytes="+nStartPos+"-"; @0NJ{  
httpConnection.setRequestProperty("RANGE",sProperty); 0fArF*  
Utility.log(sProperty); o ehaQ#e  
1/;o  
Y3Oz'%B  
InputStream input = httpConnection.getInputStream(); D#Kuo$  
//logResponseHead(httpConnection); fThgK;Qy'U  
n?xTkkr0  
tU@zhGb  
byte[] b = new byte[1024]; "35A/V  
int nRead; -tLO.JK<  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c5% 6Y2W0  
{ e,gyQjJR  
nStartPos += fileAccessI.write(b,0,nRead); pHC /(6?  
//if(nThreadID == 1) .c+9P<VmC}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @?k J).  
} #_JYh?  
Q@S-f:!  
$IX\O  
Utility.log("Thread " + nThreadID + " is over!"); O )d[8jw"  
bDownOver = true; * F4UAQzYb  
//nPos = fileAccessI.write (b,0,nRead); nP3  E  
} UvJ; A  
catch(Exception e){e.printStackTrace ();} h6v077qG  
} b5a.go  
} q7\Ovjs0  
-c*\o3)  
nZk +  
//打印回应的头信息 *O~e T  
public void logResponseHead(HttpURLConnection con) %*}Y6tl'|  
{ "ju'UOcS/  
for(int i=1;;i++) iE].&>w  
{ F@YKFk+a  
String header=con.getHeaderFieldKey(i); BuOgOYh9  
if(header!=null) Fhf<T`  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EGVM)ur  
Utility.log(header+" : "+con.getHeaderField(header)); mtAE  
else ?C-Towo=i  
break; Ib=x~za@n  
} q v*7K@  
} @N@F,~[RR2  
3gEMRy*+  
HD>q(cK_|8  
public void splitterStop() bulS&dAX  
{ YJeyIYCs<  
bStop = true; #5} wuj%5  
} O`[aU%4b  
W?woNt'n  
4rg2y]  
} soRv1)el  
yx38g ca  
zeb=8 Dg :  
/* tq1CwzRX  
**FileAccess.java 4T6 {Y  
*//文件访问(定位,写) IxZb$h[  
package NetFox; V)ig)(CT  
import java.io.*; Y f@e=:  
L{-LX= G^  
KLWn?`  
public class FileAccessI implements Serializable{ .B2]xfo"`  
3?I;ovsM  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Pe73g%  
RandomAccessFile oSavedFile; , t5 '  
long nPos; $;N*cH~  
4<dcB@v  
*cuuzi&  
public FileAccessI() throws IOException E H:T  
{ FzQTDu9  
this("",0); 'k0[rDFc#3  
} D\dWt1n  
l7H qo)  
YyAJ m^o  
public FileAccessI(String sName,long nPos) throws IOException dO> VwP  
{ '7^M{y/dU  
oSavedFile = new RandomAccessFile(sName,"rw"); RD7^&  
this.nPos = nPos; sUJ%x#u}Fk  
oSavedFile.seek(nPos); )SF}2?7e  
} `{k"8#4:qA  
1RcSTg  
U1_@F$mq<  
public synchronized int write(byte[] b,int nStart,int nLen) P262Q&.}d  
{ }o4N<%/+  
int n = -1; v{zMO:3  
try{ }/tf>?c  
oSavedFile.write(b,nStart,nLen); #'D" 'B  
n = nLen; eV:9y  
} C?v[Z]t  
catch(IOException e)  xw^R@H  
{ zi R5:d3   
e.printStackTrace (); #6Fez`A  
} 'm1N/)F  
B~]5$-  
Qd}m`YW-f$  
return n; VVH.2&`I  
} d@`M CchCB  
]^':Bmq  
|F,R&<2  
} dI&!e#Y  
j`^$#  
$vC1 K5sLk  
/* QO;N9ZI  
**SiteInfoBean.java zJP6F.Ov!  
*/ @k[R/,#'[t  
package NetFox; F <>!kK/c  
B~o\+n  
3bk|<7tl  
public class SiteInfoBean { ) [0T16  
f` =CpO*  
_XJ2fA )  
private String sSiteURL; //Site's URL (" LQll9  
private String sFilePath; //Saved File's Path + a- 6Q ~  
private String sFileName; //Saved File's Name +fvaUV_-  
private int nSplitter; //Count of Splited Downloading File d ;vT ~;  
6"Bic rY  
* #jsgj[  
public SiteInfoBean() | N0Z-|  
{//nSplitter的缺省值为5 q0f3="  
//default value of nSplitter is 5 ^O^l(e!3  
this("","","",5); lY|Jr{+Ln  
} U2uF&6v  
}*.0N;;C  
*K> l*l(f]  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =]:>"_jN  
{ GKN%Tv:D_  
sSiteURL= sURL; !vG'J\*xc  
sFilePath = sPath; WVVJ  
sFileName = sName; f|O{#AC  
this.nSplitter = nSpiltter; n6s}ww)  
(Qa/EkE^*w  
Cmc3k,t  
} aLIBD'z  
0a-:<zm  
/rUo{j  
public String getSSiteURL() W6On9 3sa  
{ 9Xx's%U  
return sSiteURL; m(pE5B(  
} EwOV;>@T?  
V(Ub!n:j  
K|dso]b/  
public void setSSiteURL(String value) .e_cgad :  
{ ^]{R.(#z  
sSiteURL = value; ByCnD  
} `jwa<N4e@  
7o8{mp'_  
V<Z[ nq  
public String getSFilePath() s kg*  
{ ]X I*Wsn  
return sFilePath; /_ `lz^  
} gx%|Pgd  
ABUSTf<  
@}u9Rn*d;  
public void setSFilePath(String value) ],P;WPU  
{ v{}#?=I5  
sFilePath = value; ,"B+r6}EF  
} 9K9DF1SOa  
=i~}84>  
-jMJAYjV  
public String getSFileName() G "73=8d  
{ ~%YBI9$+  
return sFileName; *zr(Zv  
} 6`f2-f9%iq  
,yd?gP-O  
E9~Ghx.   
public void setSFileName(String value) K_dOq68_  
{ kT;S4B  
sFileName = value; -wjN"g<  
} F&&$Qn_+  
br|;'i%(  
dPhQ :sd>  
public int getNSplitter() ]\!?qsT3}  
{ jYe'V#5S#  
return nSplitter; U"Zmv  
} )I3NeKWz  
?Wz8[u  
eopD5  
public void setNSplitter(int nCount) L'F<ev  
{ {?yr'*  
nSplitter = nCount; 6L)%T02C  
} s0PrbL%_`  
} ^Vpq$'!  
gvL f|+m  
nw-I|PVTNa  
/*  ]C) 4  
**Utility.java J>\B`E  
*/ 92EWIHEWZ  
package NetFox; Z?\2F%  
}mAa}{_  
rb|U;)C  
public class Utility { B'fb^n<  
5O\*h;U 6  
3g >B"t  
public Utility() a[ex[TRKe  
{ ,G2TVjz  
2sJ(awN>  
92 [; Y  
} 3\B>lKhQ  
vvm0t"|\  
//线程睡眠 +(h\fm7*-  
public static void sleep(int nSecond) zzyHoZJP  
{ rnF/H=I/  
try{ p>upA)W]  
Thread.sleep(nSecond); d!$Z (W0  
} 7k rUKYVo  
catch(Exception e) _ ]Z s,Hy  
{ q#s,- uu  
e.printStackTrace (); !TUrQ  
} ,gS;m &!'J  
} m&?#;J|B$  
9M:O0)s  
//日志 cZ|\.0-  
public static void log(String sMsg) v#!%GEg1r  
{ v61[.oS  
System.err.println(sMsg); ia MUsa{  
} <"_d]?,  
IyPwP*A  
:AE&Ny4  
public static void log(int sMsg) <>8WQn,K  
{ mVy|{Oh  
System.err.println(sMsg); ]bK=FIK2  
} 9pX&ZjYP-  
} T87 m?a$  
gntxNp[9T  
3d e_V|%  
/* >M`CVUf  
**TestMethod.java bdc&1I$  
*/ s#WAR]x0x  
package NetFox; bLwAXW2K+  
iB498t  
3J5!oF{H  
public class TestMethod { 'JRvP!]  
`tn{ei  
D8xmE2%  
public TestMethod() 1A\OC  
{ ///xx/weblogic60b2_win.exe H(Z88.OM  
try{ MerFZd 1  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4B^ZnFJ%m  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u4/kR  
SiteFileFetch fileFetch = new SiteFileFetch(bean); {o>j6RS\  
fileFetch.start(); nYX@J6!  
} !Y[lQXv  
catch(Exception e){e.printStackTrace ();} zlEX+=3  
P3=W|81e  
,=#F//  
} BYMi6wts  
o<|P9#(U"  
}3OKC2K~  
public static void main(String[] args) K[!&b0O  
{ [_Qa9e  
new TestMethod(); @]ytla>d  
} =_:et 0  
} d%o&+l#  
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