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http断点续传简单实现(java)

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/* =pcj{B{qa  
**SiteFileFetch.java #K! Df%,<  
*/ |-_5ou N.  
package NetFox; 45j+n.9=  
import java.io.*; (4 {49b  
import java.net.*; U&3*c+B4  
!icpfxOpjQ  
OV8b~k4=  
public class SiteFileFetch extends Thread { Ti3BlWQH  
{u.V8%8  
bOck^1Hky  
SiteInfoBean siteInfoBean = null; //文件信息Bean kM3BP& 3m1  
long[] nStartPos; //开始位置 p!aeL}g`  
long[] nEndPos; //结束位置 g-p OO/|  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 SC2C%.%l`  
long nFileLength; //文件长度 45MK|4\Y_  
boolean bFirst = true; //是否第一次取文件 t48(GKF  
boolean bStop = false; //停止标志 {C]M]b*F6(  
File tmpFile; //文件下载的临时信息 iW"L!t#\|  
DataOutputStream output; //输出到文件的输出流 1wc -v@E  
-'PpY302  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 6eDIS|/  
public SiteFileFetch(SiteInfoBean bean) throws IOException GYO\l.%V5y  
{ 4E |6l  
siteInfoBean = bean; iY|YEi8  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); GoEIY  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); fSqbGoIQ  
if(tmpFile.exists ()) dWqFP  
{ GmL|76  
bFirst = false; jm-0]ugY&`  
read_nPos(); 0dcXgP  
} {my=Li<_H  
else OaCL'!  
{ uAvs  
nStartPos = new long[bean.getNSplitter()]; mLk Z4OZ  
nEndPos = new long[bean.getNSplitter()]; z)VIbEy  
} "]_|c\98  
-/gS s<"  
" DlC vjc  
@eT sS%f2  
} Ar<OP'C  
6ZG)`u".("  
owMH  
public void run() T![K i  
{ .897Z|$VB  
//获得文件长度 2 !;4mij,  
//分割文件 YQ]H3GA  
//实例FileSplitterFetch y{<#pS.  
//启动FileSplitterFetch线程 f]'@Vt>  
//等待子线程返回 <;6])  
try{ D@^F6am%  
if(bFirst) bg HaheU  
{ KFZ[gqW8YY  
nFileLength = getFileSize(); QhGg^h%6  
if(nFileLength == -1) Rm*}<JN31  
{ y2+a2  
System.err.println("File Length is not known!"); 4C*3#/TR  
} jVA~]a  
else if(nFileLength == -2) 'd t}i<  
{ Y;&#Ur8q  
System.err.println("File is not access!"); M)J*Df0@  
} ^TEODKS  
else \W}EyA  
{ lTB!yF.r|  
for(int i=0;i<nStartPos.length;i++) Pj.~|5gnf  
{ ,#E5/'c`  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); %UQ{'JW?K  
} jO,<7FPs5  
for(int i=0;i<nEndPos.length-1;i++) aydal 9M  
{ r6$=|Yto  
nEndPos = nStartPos[i+1]; 0wkLM-lN  
} eYcx+BJ  
nEndPos[nEndPos.length-1] = nFileLength; k_a'a)`$6  
} ob00(?;H  
} NZTYT\7  
'u3+k.  
? w?k-v  
//启动子线程 =+"'=o  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;yZ N "r  
for(int i=0;i<nStartPos.length;i++) o 4b{>x  
{ KB"iF}\P0  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r{Q< a  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V^{!d}  
nStartPos,nEndPos,i); xI<dBg|]+  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f oVD+\~Y  
fileSplitterFetch.start(); )j6>b-H   
} *h4m<\^U  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Az-!LAu9 R  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3E ZwF  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =CVT8(N*  
nEndPos = " + nFileLength); [;=ky<K0E  
// fileSplitterFetch[nPos.length-1].start(); cLU*Tx\  
Q$vr`yV#=6  
9(l'xuX  
//等待子线程结束 =_dd4`G&<  
//int count = 0; *i{.@RX?  
//是否结束while循环 8QN8bGxK   
boolean breakWhile = false; m6x. "jG  
Yy)a,clZ*$  
cA%U  
while(!bStop) Zd(d]M_x  
{ 7:L~n(QpP  
write_nPos(); 668bJ.M\O  
Utility.sleep(500); U(N$6{i_  
breakWhile = true; M([H\^\:  
~yi&wbTjM  
\!QF9dP4  
for(int i=0;i<nStartPos.length;i++) =Yj[MVn  
{ ]'h)7  
if(!fileSplitterFetch.bDownOver) Rdg0WT*;j  
{ O|RO j  
breakWhile = false; DjIswI1I  
break; X{xJ*T y'  
} 7h]R{_  
} a1`cI5n  
if(breakWhile) +7/*y}.U  
break; `Y\/US70{c  
3K!0 4\  
|2<f<k/UT  
//count++; $cOD6Xr)d  
//if(count>4) %gMpV  
// siteStop(); W-PZE|<  
} -NPk N%h  
wDhcHB  
'h^DI`  
System.err.println("文件下载结束!"); otSPi7|k  
} C55n  
catch(Exception e){e.printStackTrace ();} Kg`x9._2  
} ]0i2 ]=J&,  
pmyM&'#Id  
I A`8ie+  
//获得文件长度 87(^P3;@  
public long getFileSize() ;]M67ma7C  
{ 'D"K`Vw  
int nFileLength = -1; R[9PFMn  
try{ ]XG n2U\  
URL url = new URL(siteInfoBean.getSSiteURL()); 9BD|uU;0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m90R8  V  
httpConnection.setRequestProperty("User-Agent","NetFox"); .XKvk(9  
V&oT':%q  
g**% J Xo  
int responseCode=httpConnection.getResponseCode(); *z"1MU  
if(responseCode>=400) OEE{JVeI  
{ =P;;&j3Z  
processErrorCode(responseCode); ZU.)K>'  
return -2; //-2 represent access is error :ZfUjqRE  
} f5b`gvCY,#  
pd>a6 lI`  
\Tf{ui  
String sHeader; /N]Ow  
fd"~[ z[  
sR>;h /  
for(int i=1;;i++) 4`-?r%$,:  
{ 31sgf5 s  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C$RAJ  
//Utility.log(in.readLine()); Vc52s+7=8  
sHeader=httpConnection.getHeaderFieldKey(i); b)hOzx  
if(sHeader!=null) HA.NZkq.tV  
{ y]pN=<*h5  
if(sHeader.equals("Content-Length")) ]6%%X+$7  
{ Q xF8=p  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~:}XVt0%8  
break; qv*uM0G6i  
} h NOYFH  
} "4k=(R?  
else r{!"%03H_  
break; uU ?37V  
} S[hJ{0V  
} E"1 ;i  
catch(IOException e){e.printStackTrace ();} ]b~2Dap  
catch(Exception e){e.printStackTrace ();} YV3TxvXMR  
1yaIV+_y/  
~\:j9cC  
Utility.log(nFileLength); V0'p1J tD  
.FbZVYc]  
h>^jq{yu  
return nFileLength; : 9?Cm`  
} c7l!G~yx'  
So\|Ye  
>_0 i=.\  
//保存下载信息(文件指针位置) Q"6hD?6.  
private void write_nPos() #:vDBP05.m  
{ qgC-@I  
try{ 4=F]`Lql  
output = new DataOutputStream(new FileOutputStream(tmpFile));  `\|3 ~_v  
output.writeInt(nStartPos.length); _/]:=_bf_z  
for(int i=0;i<nStartPos.length;i++) @Uj _+c q  
{ t1:S!@  
// output.writeLong(nPos); 4'{hI;&a&  
output.writeLong(fileSplitterFetch.nStartPos); 3^A/`8R7K  
output.writeLong(fileSplitterFetch.nEndPos); ,F?~'-K  
} i9@;,4f  
output.close(); b?2X>QJ  
} ;+ C o!L  
catch(IOException e){e.printStackTrace ();} ^0-e,d 9h  
catch(Exception e){e.printStackTrace ();} sPE)m_u  
} yrE,,N%I  
w-'D*dOi  
_5U%'\5s  
//读取保存的下载信息(文件指针位置) tgvpf /cQ  
private void read_nPos() "\zj][sL  
{ _Xk03\n6  
try{ L VU)W^  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n<%=~1iY+  
int nCount = input.readInt(); *t?~)o7  
nStartPos = new long[nCount]; J+cAS/MYX  
nEndPos = new long[nCount]; {Ukc D+.Y  
for(int i=0;i<nStartPos.length;i++) }[KDE{,V  
{ 6& &}P79  
nStartPos = input.readLong(); Pi"~/MGP$  
nEndPos = input.readLong(); iFwyh`Bcg  
} EBIa%,  
input.close(); vNK`Y|u@  
} ezg^5o;  
catch(IOException e){e.printStackTrace ();} p'Y&Z?8  
catch(Exception e){e.printStackTrace ();} '?`@7Eol  
} FD XWFJ  
E*r  
@tE&<[e  
private void processErrorCode(int nErrorCode) Rg8m4xw  
{ s}[A4`EWH  
System.err.println("Error Code : " + nErrorCode); 38w.sceaT  
} C)J_lI{^  
s0 \f9D  
n{.*El>{  
//停止文件下载 C-a*EG  
public void siteStop() 3WO#^}t  
{ t?]\M&i&  
bStop = true; 55>" R{q  
for(int i=0;i<nStartPos.length;i++) +7i7`'9pd  
fileSplitterFetch.splitterStop(); I=4Xv<F  
8 l'bRyuS  
>bX-!<S  
} b(.-~c('  
} Xr@l+zr  
//负责部分文件的抓取 e(OwS?K  
**FileSplitterFetch.java D4=..;  
*/ IdV,%d{  
package NetFox; ,YP1$gj  
"<PoJPh  
[):{5hMA  
import java.io.*; 97qtJ(ESI  
import java.net.*; 5"-una>D  
} * ?n?'  
h*;g0QBkl  
public class FileSplitterFetch extends Thread { V-D}U$fw  
Sk6b`W7$  
;mf4 U85  
String sURL; //File URL =_$XP   
long nStartPos; //File Snippet Start Position dN$ 1$B^k  
long nEndPos; //File Snippet End Position a"0B?3*r46  
int nThreadID; //Thread's ID 4 [R8(U[g  
boolean bDownOver = false; //Downing is over RLYU\@kK?  
boolean bStop = false; //Stop identical 18DTv6?QG  
FileAccessI fileAccessI = null; //File Access interface M>*0r<qn  
E;6Y? vJ  
~-XOvKJb  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YMc8Q\*B  
{ X+]L-o6I2  
this.sURL = sURL; ~q0I7M  
this.nStartPos = nStart; [,OJX N-4s  
this.nEndPos = nEnd; W]@gQ (Ef  
nThreadID = id; 'GEBxNH:  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;;EDN45  
} Qqd6.F  
pP|,7c5  
UJee&4C-y  
public void run() 82j'MgGP  
{ (Oxz'#TX  
while(nStartPos < nEndPos && !bStop) A[u)wX^`f^  
{ Vk MinE  
l,*yEkU  
JP{UgcaF  
try{ 5SoZ$,a<e  
URL url = new URL(sURL); NoFs-GGGh  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dO>k5!ge|:  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1^Kj8*O8e  
String sProperty = "bytes="+nStartPos+"-"; Yw6DJY  
httpConnection.setRequestProperty("RANGE",sProperty); 6B7<  
Utility.log(sProperty); 1vB-M6(  
eq^TA1>T  
vS7/~:C  
InputStream input = httpConnection.getInputStream(); O0@w(L-  
//logResponseHead(httpConnection); K^"w]ii=  
NJn&>/vM  
aQ(`6DQv  
byte[] b = new byte[1024]; 7cIC&(h5  
int nRead; k4S} #!  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l% rx#;=u  
{ q:vz?G  
nStartPos += fileAccessI.write(b,0,nRead); 1*Sr5N[=  
//if(nThreadID == 1) \n[ 392  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?k [%\jq{a  
} 3LKB;  
CD^CUbGk  
c]6V"Bo}A  
Utility.log("Thread " + nThreadID + " is over!"); *f79=x  
bDownOver = true; K1:a]aU?Iu  
//nPos = fileAccessI.write (b,0,nRead); Wm<z?.lS  
}  ;KZrl`  
catch(Exception e){e.printStackTrace ();} .4wTjbO6  
} fJX\'Rc\  
} u K'<xM"%T  
A:kkCG!~Nf  
?3`q+[:  
//打印回应的头信息 3>i>@n_  
public void logResponseHead(HttpURLConnection con) ;4!=DFbU  
{ }c} ( 5  
for(int i=1;;i++) Yx6hA#7I  
{ RXBb:f  
String header=con.getHeaderFieldKey(i); W@l+ciZ_  
if(header!=null) 3@&bxYXm  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o>2e !7  
Utility.log(header+" : "+con.getHeaderField(header)); |</"N-#S  
else 6^Ph '  
break; 'g]hmE  
} IQT cYl  
} 3=Z<wD s  
;P3>>DZ  
2-~a P  
public void splitterStop() wDDxj  
{ \3r3{X _<`  
bStop = true; lY.B  
} B]1HS`*7  
x"vwWJNQ  
Xq|nJ|h  
} WM/#.  
Mec{_jiH&D  
8 4z6zFv?Q  
/* 2 #KoN8%  
**FileAccess.java qtHfz"p  
*//文件访问(定位,写) +O'vj  
package NetFox; {1~9vHAZ  
import java.io.*; CD}Ns  
Yb}w;F8(  
F+Z2U/'a  
public class FileAccessI implements Serializable{ \k;U}Te<  
`|]e6Pb  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e$/&M*0\f  
RandomAccessFile oSavedFile; h2% J/69  
long nPos; u yFn}y62  
B s,as  
@44P4?;  
public FileAccessI() throws IOException +jtA&1cf  
{ " \:ced  
this("",0); &s:=qQa1  
} @;m$ua*|:  
;`kWpM;  
~n6[$WjZA  
public FileAccessI(String sName,long nPos) throws IOException ;-Ss# &  
{ a+41Ojv (  
oSavedFile = new RandomAccessFile(sName,"rw"); ('t kZt%8  
this.nPos = nPos; >!}`%pk(  
oSavedFile.seek(nPos); -u|l}}bh  
} -l "U"U"F  
0O~p7D  
M/{g(|{  
public synchronized int write(byte[] b,int nStart,int nLen) A:eG5K}  
{ _R7 w?!t8  
int n = -1; ?>V6P_r>  
try{ Tr&E4e  
oSavedFile.write(b,nStart,nLen); o'Pu'y  
n = nLen; A W)a">|  
} t[EfOQ  
catch(IOException e) &!jq!u$(  
{ # .<V^  
e.printStackTrace (); Pd~MiyO;K  
} 2J<&rKCF  
[T`}yb@  
r~8;kcu7  
return n; "!H@k%eAM|  
} 5 lTD]d  
Q.k :\m*h  
/s c.C  
}  ]>Si0%  
i[150g?K  
W&(f&{A  
/* LmQ/#Gx  
**SiteInfoBean.java Z)&D`RCf  
*/ =-~;OH /  
package NetFox; EA|k5W*b  
(R'+jWH  
Fk1.iRVzi  
public class SiteInfoBean { ni6r{eSQ  
2yKz-"E  
$%PVJs  
private String sSiteURL; //Site's URL &[@\f^~  
private String sFilePath; //Saved File's Path :.iyR  
private String sFileName; //Saved File's Name S &JJIFftO  
private int nSplitter; //Count of Splited Downloading File 3bs4mCq  
7 ({=*  
^7aN2o3{  
public SiteInfoBean() >fzwFNdo  
{//nSplitter的缺省值为5 sG,+  
//default value of nSplitter is 5 [$a<b/4  
this("","","",5); 5| w&dM  
} g:<?  
M=y0PCD  
}"zC >eX&  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }q!_!q,@  
{ E=u/tpj  
sSiteURL= sURL; ;;V\"7q'  
sFilePath = sPath; KWhZ +i`  
sFileName = sName; - 8bNQU  
this.nSplitter = nSpiltter; H"CUZ  
6;oe=Q:Q  
;GsQR+en  
} A+ 0,i  
E'c%d[:H,  
;=jr0\|e  
public String getSSiteURL() &|5GB3H =  
{ 44sy`e  
return sSiteURL; # |^^K!%  
} a<m-V&4x  
h qmSE'8  
[s` G^  
public void setSSiteURL(String value) ?4[H]BK  
{ :\yc*OtX  
sSiteURL = value; XM~~y~j  
} jm3G?Vnq  
pCU*@c!  
fS A)G$b]  
public String getSFilePath() nl1-kB)$e|  
{ 61_f3S(u  
return sFilePath; PlCc8Zy  
} !gP0ndRJ=  
~xyw>m+o.  
v6uxxsI>Hm  
public void setSFilePath(String value) ;(6P6@+o  
{ n56;m`IU  
sFilePath = value; I*\^,ow  
} ml u 3K  
~ 3T,&?r  
&L4 q10-N  
public String getSFileName() 2 x 4=  
{ lKV"Mh+6  
return sFileName; ULBg {e?l8  
} UQT'6* !  
.q;ED`G  
mBk5+KyT  
public void setSFileName(String value) ijUzC>O+q  
{ :&VcB$  
sFileName = value; z4 M1D9iPY  
} O}Le]2'  
w'ybbv{c  
=%qEf   
public int getNSplitter() @"|i"Hk^  
{ \ijMw  
return nSplitter; GAEO$e:  
} rZwB> c  
TGV  
S~F`  
public void setNSplitter(int nCount) 7#-y-B]l  
{ :w-`PY J%G  
nSplitter = nCount; Jb(Y,LO^  
} sR_xe}-  
} >a>fb|r  
\pY^^ l*  
\4bWWy  
/* `M@Ak2gcR+  
**Utility.java Y2T$BJJ  
*/ kA#vByf`v  
package NetFox; '$m7ft}  
8i 0  
hW 2.8f$  
public class Utility { &M"ouy Zo9  
py<_HyJ  
\2X$C#8E  
public Utility() F 3RB  
{ s& yk  
3$p#;a:=n  
Utt>H@t[  
} E{Vo'!LY  
n9hm790x-  
//线程睡眠 ;b%{ilx:  
public static void sleep(int nSecond) A7-r <s  
{ <94G  
try{ *\XH+/]+  
Thread.sleep(nSecond); RtV.d \  
} 8^yJqAXK  
catch(Exception e) .y4&rF$n  
{ ?nFO:N<  
e.printStackTrace (); e~\QE0Oe:  
} zlf} .  
} Hi,t@!!  
ffcLuXa  
//日志 @}LZ! y  
public static void log(String sMsg) RA/EpD:H  
{ ps1@d[n  
System.err.println(sMsg); sH!O0WL  
} lZ+!H=`  
 <!'M} s  
x:z0EYL  
public static void log(int sMsg) x8[MP?Wz  
{ =dH$2W)G  
System.err.println(sMsg); HFtf  
} UTk r.T+2X  
} :jem~6i  
*^XbDg9  
(GU9p>2  
/* lAASV{s{  
**TestMethod.java 4tc:.  
*/ )ly ^Ox  
package NetFox; g`,AaWlF  
;Ss$2V'a  
y{=NP  
public class TestMethod { d#_m.j  
Vb4;-?s_  
Tj/GClD:%  
public TestMethod() ;!u;!F!i  
{ ///xx/weblogic60b2_win.exe Kn}ub+ "J  
try{ dbF M,"^  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Nw<P bklz  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SN">gmY+  
SiteFileFetch fileFetch = new SiteFileFetch(bean); vA&Vu"}S  
fileFetch.start(); ;5S}~+j  
} \C|cp|A*&  
catch(Exception e){e.printStackTrace ();} lpC @I^:  
+1`t}hO  
9`Q@'( m  
} IB$7`7  
jj&s} _75  
q~Jq/E"f  
public static void main(String[] args) SS3-+<z  
{ fC<m^%*zgA  
new TestMethod(); z@h~Vb&I  
} s3QEi^~  
} "^rNr_  
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