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http断点续传简单实现(java)

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/* m|?" k38  
**SiteFileFetch.java Q'Jpsmwu  
*/ aD2CDu  
package NetFox; 2AdHj&XE  
import java.io.*; ~i_ R%z:y  
import java.net.*; UNZVu~WnF  
8L9S^ '  
U}vtVvx  
public class SiteFileFetch extends Thread { RAx]Sp Q-S  
omUl2C  
n.H`1@  
SiteInfoBean siteInfoBean = null; //文件信息Bean BS<>gA R;/  
long[] nStartPos; //开始位置 r<f-v_bxF  
long[] nEndPos; //结束位置 EBn:[2  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 n4d(`  
long nFileLength; //文件长度 *!7SM 7  
boolean bFirst = true; //是否第一次取文件 \8>N<B)  
boolean bStop = false; //停止标志 BKP!+V/  
File tmpFile; //文件下载的临时信息 ?[>BssW  
DataOutputStream output; //输出到文件的输出流 )mo|.L0  
*}WqYqOow  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) HjF'~n  
public SiteFileFetch(SiteInfoBean bean) throws IOException aid)q&AcQ  
{ &MGgO\|6  
siteInfoBean = bean; jQwg)E+o;  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); J`D<  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ;uo|4?E:\(  
if(tmpFile.exists ()) cF<DUr)Ve  
{ O6/=/-?N=c  
bFirst = false; k3|9U'r!c  
read_nPos(); PQ!?gj  
} eEds-&_  
else 'w$we6f  
{ nh.v?|  
nStartPos = new long[bean.getNSplitter()]; j~j V`>A  
nEndPos = new long[bean.getNSplitter()]; =VI`CBQ/Um  
} %$-3fj7  
x:wq"X  
0BwQ!B.  
rN!9&  
} 'A@Oia1;{  
WAXrA$:3J  
{ dx yBDK  
public void run() ).#D:eO[~  
{ `fE:5y  
//获得文件长度 M(f*hOG{Y  
//分割文件 Vblf6qaBs  
//实例FileSplitterFetch ea;c\84_N  
//启动FileSplitterFetch线程 eMMiSO!3  
//等待子线程返回 HE .Dl7 {  
try{ Gqu0M`+7  
if(bFirst)  k`zK  
{ YO4ppL~xe  
nFileLength = getFileSize(); w9?wy#YI  
if(nFileLength == -1) leqSS}KU+  
{ K?<Odw'k  
System.err.println("File Length is not known!"); j{+I~|ZB,  
} |vE#unA  
else if(nFileLength == -2) *>H'@gS  
{ n6+M qN  
System.err.println("File is not access!"); 6*oTT(0<p  
} 0 #; s{7k  
else #Yb9w3N  
{ ^O9m11  
for(int i=0;i<nStartPos.length;i++) g}`CdVQ2M<  
{ )n61IqrW  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); fC:\Gh5  
} z>#$#:Z4  
for(int i=0;i<nEndPos.length-1;i++) 5 `mVe0uI  
{ C 5!6k1TcE  
nEndPos = nStartPos[i+1]; T[K?A+l  
} w0OK. fj  
nEndPos[nEndPos.length-1] = nFileLength; e/l?|+m 6  
} }{PtQc6RL!  
} Xq$0% WjG  
E0'6!9y  
BU .G~0  
//启动子线程 u9%:2$[  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ov}{UP]a?  
for(int i=0;i<nStartPos.length;i++) C'"6@-~  
{ {i?K~| h  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e q.aN3KB"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 35\0g&  
nStartPos,nEndPos,i); 3Sb%]f5(  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3Q6#m3AWY  
fileSplitterFetch.start(); F= lj$?4{  
} Q 7?4GxMj  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Msdwv.jM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +1A<kJ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @ uWD>(D  
nEndPos = " + nFileLength); 8XE0 p7  
// fileSplitterFetch[nPos.length-1].start(); :\cJ vm  
hYx^D>}]  
{=Y&q~:8v  
//等待子线程结束 l0,O4k2'  
//int count = 0; &0blHDMj{#  
//是否结束while循环 N{@ eV][Q  
boolean breakWhile = false; Np)!23 "  
3`I_  
`hhG^ O_  
while(!bStop)  6<GWDO  
{ J)+eEmrU  
write_nPos(); Q?q m~wD  
Utility.sleep(500); ;W"[,#2TM  
breakWhile = true; w|ei*L  
k#M W>  
T9.gs}B0  
for(int i=0;i<nStartPos.length;i++) ]].21  
{ `_ L|I s=n  
if(!fileSplitterFetch.bDownOver) D[?|\?  
{ _u!G 6   
breakWhile = false; |0 VP^md  
break; G)`MoVH1  
}  -"H9W:  
}  O@$i  
if(breakWhile) _69\#YvCG  
break; M>j)6?n`_  
.})8gL7 V  
 '%4,!  
//count++; )$i3j 1[;  
//if(count>4)  q\"$~*  
// siteStop(); 2:yv:7t/  
} 4 n( f/  
w5Z3e^g  
4#uoPkLK  
System.err.println("文件下载结束!"); SfR_#"Uu  
} [8n4lE[)"  
catch(Exception e){e.printStackTrace ();} ??;[`_h{bz  
} Z5K,y19/~  
I1jF`xQ&0  
a{=~#u8  
//获得文件长度 9|,AhyhO  
public long getFileSize() <Th.}=  
{ YVi]f2F%  
int nFileLength = -1; hGLBFe#3  
try{ P[~a'u  
URL url = new URL(siteInfoBean.getSSiteURL()); 7y&`H  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b7/4~_s  
httpConnection.setRequestProperty("User-Agent","NetFox"); jLg4_N1SD  
>E#4mm  
L\5n!(,0  
int responseCode=httpConnection.getResponseCode(); Qpc>5p![3  
if(responseCode>=400) Vow+,,oh  
{ t1S\M%?  
processErrorCode(responseCode); 3ly|y{M",  
return -2; //-2 represent access is error #<:khs6  
} a>6p])Wh  
(J;<&v}Gad  
MG|NH0k  
String sHeader; 6IA~bkc}  
L '=3y$"],  
P=.W.oS  
for(int i=1;;i++) uWSG+  
{ MLl:)W*  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]v#Q\Q8>  
//Utility.log(in.readLine()); d?JVB  
sHeader=httpConnection.getHeaderFieldKey(i); .+.Pc_fv  
if(sHeader!=null) q :gH`5N  
{ e5dwq  
if(sHeader.equals("Content-Length")) b1+Nm  
{ PeOgXg)L`z  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8@!SM  
break; 2B|3`trY4x  
} | =&r) ~  
} h4U .wk  
else q;+qIV&.:  
break; 'sC{d&c  
} Rh39x-`Z  
} .[7m4iJf  
catch(IOException e){e.printStackTrace ();} / wEr>[8S  
catch(Exception e){e.printStackTrace ();} -7CkOZT  
Z"A:^jZ<s  
RSy1 wp4W  
Utility.log(nFileLength); i^yQ; 2 -  
 (1ebE  
}wn GOr  
return nFileLength; ,%u\2M  
} 4JucNGv  
&" =inkh  
U7O2.y+  
//保存下载信息(文件指针位置) l#Iof)@#  
private void write_nPos() -k'=s{iy  
{ sD M!Uv2n  
try{ %"o4IYV#  
output = new DataOutputStream(new FileOutputStream(tmpFile)); "p<f#s}  
output.writeInt(nStartPos.length); 3N?uY2  
for(int i=0;i<nStartPos.length;i++) |(Sqd;#v  
{ Rzz*[H  
// output.writeLong(nPos); zZ kwfF  
output.writeLong(fileSplitterFetch.nStartPos); !5pp A  
output.writeLong(fileSplitterFetch.nEndPos); N52N ^X>  
} lgU7jn  
output.close(); k(et b#  
} :[F w c  
catch(IOException e){e.printStackTrace ();} /@q_`tU  
catch(Exception e){e.printStackTrace ();} 6x_8m^+m  
} ${ e{#  
07n=H~yU  
P'zA=Rd&~>  
//读取保存的下载信息(文件指针位置) g=b 'T-  
private void read_nPos() $H?v  
{ \SyfEcSf2v  
try{ %h^; "|Z  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J-=&B5"O>  
int nCount = input.readInt(); HyZh27PE  
nStartPos = new long[nCount]; yhZ2-*pTg  
nEndPos = new long[nCount]; 4W6gKY  
for(int i=0;i<nStartPos.length;i++) 2: fSn&*/>  
{ iX}EJD{f  
nStartPos = input.readLong(); pX"f "  
nEndPos = input.readLong(); I/t2c=f  
} GDhg VOW(  
input.close(); PE-Vx RN)  
} TEv3;Z*N  
catch(IOException e){e.printStackTrace ();} fi`*r\  
catch(Exception e){e.printStackTrace ();} F@[l&`7  
} A+>+XA'  
(;\JCeGA  
iWO16=  
private void processErrorCode(int nErrorCode) fE,\1LK4  
{ .- uH ax0  
System.err.println("Error Code : " + nErrorCode); K%)u zP  
} o#CNr5/  
Z+JPxe#7  
_>0 I9.[5  
//停止文件下载 @}qMI   
public void siteStop() Iy'a2@   
{ :(E.sT "R  
bStop = true; b@"#A8M  
for(int i=0;i<nStartPos.length;i++) L~=h?C<  
fileSplitterFetch.splitterStop(); Zg_ fec~6q  
-6@#Nq_iWU  
AfB,`l`k  
} =[`B -?  
} \9jEpE^Ju(  
//负责部分文件的抓取 CN+[|Mz*p  
**FileSplitterFetch.java M:rE^El  
*/ ^,*!Qk<c  
package NetFox; ,'Zs")Ydp  
t,Ss3  
v*U OD'tk  
import java.io.*; Z7J8%ywQ  
import java.net.*; imC>T!-7  
`r+zNJ@q  
bdbTK8-  
public class FileSplitterFetch extends Thread { Lk#8G>U  
8`Ih> D c  
4c0 =\v  
String sURL; //File URL ,%6!8vX  
long nStartPos; //File Snippet Start Position %=e^MN1  
long nEndPos; //File Snippet End Position h6`v%7H?  
int nThreadID; //Thread's ID lsq\CavbM  
boolean bDownOver = false; //Downing is over +6-_9qRq  
boolean bStop = false; //Stop identical zO)Bf(  
FileAccessI fileAccessI = null; //File Access interface UXgeL2`;  
b v5BV  
~T">)Y~+xI  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WstX>+?'  
{ B:oE&Ahh{  
this.sURL = sURL; +7E&IK  
this.nStartPos = nStart; E7 mB=bt>=  
this.nEndPos = nEnd; J@$KF GUs  
nThreadID = id; I'[gGK4 F  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &1 t84p:^=  
} JP{Y Q:NF  
(_IPz)F  
eU(cn8/}  
public void run() oDW)2*8yF  
{ _O#R,Y2#  
while(nStartPos < nEndPos && !bStop) zPm|$d  
{ *E.uqu>I  
CT{mzC8  
A9Kt^HR  
try{ H'a6] ]2  
URL url = new URL(sURL);  \uG^w(*)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ++\s0A(e  
httpConnection.setRequestProperty("User-Agent","NetFox"); ze"`5z26|  
String sProperty = "bytes="+nStartPos+"-"; lq}m0}9<  
httpConnection.setRequestProperty("RANGE",sProperty); '"C& dia  
Utility.log(sProperty); me@k~!e"z  
_*w kTI+j  
^i[bo3  
InputStream input = httpConnection.getInputStream(); F81Kxcs  
//logResponseHead(httpConnection); %_ (Xn  
2=IZD `{!  
br;~}GR_h  
byte[] b = new byte[1024]; %t*KP=@  
int nRead; <g$bM;6%  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w5<&b1:  
{ k 5gvo  
nStartPos += fileAccessI.write(b,0,nRead); yRy^'E~  
//if(nThreadID == 1) +k;][VC[O  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6DVHJ+WTV  
} g|Xjw Ti8$  
s{uSU1lQn  
:d1Kq _\K  
Utility.log("Thread " + nThreadID + " is over!"); }Jo}K) >!  
bDownOver = true; T&ib]LmR  
//nPos = fileAccessI.write (b,0,nRead); sjy/[.4-  
} vyBx|TR  
catch(Exception e){e.printStackTrace ();} xey?.2K1A  
} d1}cXSQ1T  
} T s9go  
o*5b]XWw  
@{@DGc  
//打印回应的头信息 (j&7`9<5  
public void logResponseHead(HttpURLConnection con) \2Yo*jE}  
{ m$`4.>J  
for(int i=1;;i++) J3 xi5S  
{ Ri/D>[  
String header=con.getHeaderFieldKey(i); ,a3M*}Y ~3  
if(header!=null) af_b G;  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1}q(Pn2  
Utility.log(header+" : "+con.getHeaderField(header)); ~? n)/i("  
else 5Z>+NKQ  
break; \7WZFh%:  
} {!*dk V  
} | MXRNA~  
|@rYh-5  
QSx4M  
public void splitterStop() N&G; `  
{ 2OwO|n  
bStop = true; RY}:&vWDk  
} YK V"bI  
W]5sqtF;6  
mr+8[0  
} &4m;9<8\  
<3 I0$?xL  
DfZ)gqp/Av  
/* snVeOe#'S  
**FileAccess.java ,#.9^J  
*//文件访问(定位,写) 3J[ 5^  
package NetFox; LIh71Vg/cc  
import java.io.*; o(YF`;OhvS  
Ym wb2]M  
2 W Wr./q  
public class FileAccessI implements Serializable{ a;v;%rs  
A}CpyRVCn  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Lu[xoQ~I  
RandomAccessFile oSavedFile; J5zu}U?  
long nPos; M5{vYk>,1Q  
xL|4'8  
71G00@&w9D  
public FileAccessI() throws IOException (RLJ_M|;/b  
{ GD<pqm`vVY  
this("",0); 8]&lUMaqVZ  
} hQ Lh}}B  
k(wJ6pc  
wb6$R};?  
public FileAccessI(String sName,long nPos) throws IOException s/OXZ<C|  
{ 8Og)(BC  
oSavedFile = new RandomAccessFile(sName,"rw"); z1LY|8$G  
this.nPos = nPos; D,SL_*r{  
oSavedFile.seek(nPos); .GuZV'  
} fqZ+CzH  
Nu6]R677Y  
l]mn4cn3  
public synchronized int write(byte[] b,int nStart,int nLen) `bEum3l\6]  
{ &;@U54,wV  
int n = -1;  DZ&AwF  
try{ jIL$hqo  
oSavedFile.write(b,nStart,nLen); z<s4-GJ)?  
n = nLen; YbE1yOJ&m  
} !' jXN82  
catch(IOException e) UE/N-K)`  
{ )4bZ;'B5  
e.printStackTrace (); J9`[Qy\  
} Gq^#.o]  
Zbjj>*2%^  
}{@RO./)[  
return n; ]@7]mu:oL  
} n`g:dz  
l%9nA.M'  
k<\]={ |=  
} ^1NtvQe@Y\  
! jb{q bq  
^p!bteA>  
/* Ld YaJh~h  
**SiteInfoBean.java 7`6JK  
*/ ^Sz?c_<2P  
package NetFox; !YEU<9  
Ue0Q| h  
k0R;1lZ0n  
public class SiteInfoBean { Eb=;D1)y]  
"6%vVi6  
9wC:8@`6E  
private String sSiteURL; //Site's URL 9 ulr6  
private String sFilePath; //Saved File's Path wq"AWyu  
private String sFileName; //Saved File's Name yy-\$<j  
private int nSplitter; //Count of Splited Downloading File me`( J y<  
QZ54Osdl  
mLn =SU{#  
public SiteInfoBean() Q{Lsr,  
{//nSplitter的缺省值为5 ^NTOZ0x~#  
//default value of nSplitter is 5 Ctxx.MM  
this("","","",5); :}18G}B  
} _;+N=/l0  
q3E_.{t  
1f1J'du  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WtTwY8HC  
{ weiqt *,8  
sSiteURL= sURL; 'E,Bl]8C5  
sFilePath = sPath; xbA% 'p  
sFileName = sName; lYu1m  
this.nSplitter = nSpiltter; jq&$YmWp  
mckrR$>  
S,,3h0$X  
} #YSUPO%F  
2JYt.HN  
w{"GA ~=  
public String getSSiteURL() ;pNHT*>u,  
{ U{>eE8l  
return sSiteURL; Q(KLx)  
} ]Zim8^n?`.  
4 1TB  
VPTT* a`  
public void setSSiteURL(String value) WLWE%bDP  
{ 'gojP  
sSiteURL = value; BKm$H! u  
} 97Qng*i  
hqY9\,.C  
'.@R_sj   
public String getSFilePath() p\8cl/~  
{ t?]6>J_V  
return sFilePath; 1h+!<c q  
} 0 n,5"B  
ys;e2xekg  
v[6BESu  
public void setSFilePath(String value) d/(=q  
{ 0{Kl5>Z9M  
sFilePath = value; zux+ooU  
} |b/J$.R  
=3oz74O[  
Md {,@ G  
public String getSFileName() <E BgHD)  
{ asW1GZO  
return sFileName; KW&&AuPb}  
} q'2PG@  
&bj :,$@  
%i%Xi+{3  
public void setSFileName(String value) :*&wnQMKR  
{ =O)JPo&iwY  
sFileName = value; u?g!E."v  
} _u;^w}0  
}C7tlA8,7  
<'~8mV1  
public int getNSplitter() G-3.-  
{ !nj%n  
return nSplitter; &,."=G  
} 2c%}p0<;|?  
@mJN  
^ MJGY,r6b  
public void setNSplitter(int nCount) {|xwvTl J  
{ Uzb"$Ue4  
nSplitter = nCount; ;$&-c/]F#  
} YF>t{|  
} 4!k={Pd  
\ @N>38M  
Lf0Hz")  
/* 2 J4|7UwJ  
**Utility.java rY!uc!  
*/ XFu@XUk!K  
package NetFox; pXFNK" jm  
GoEIY  
@IiT8B  
public class Utility { w ^<Y5K  
dWqFP  
J82{PfQ"  
public Utility() iQ9#gPk_9  
{ xD\Km>|i  
gv[7h'}<  
5GJ0EZ'X  
} ZHC sv]l  
-/gS s<"  
//线程睡眠 %o"Rcw|  
public static void sleep(int nSecond) +cV!=gDT  
{ K%pmE?%,8  
try{ ~o/^=:*  
Thread.sleep(nSecond); /2@%:b)  
} 5R=lTx/Hj  
catch(Exception e) D} .t  
{ {-Y_8@&  
e.printStackTrace (); `C*!de]Y%  
} $k`8Zx w  
} KFZ[gqW8YY  
7@lXN8_f  
//日志 y2+a2  
public static void log(String sMsg) p_z"Uwp  
{ DYWC]*  
System.err.println(sMsg); &16bZw  
} R&4E7wrdP  
"qj[[L Q  
m_(hCY=Q$  
public static void log(int sMsg) ,#E5/'c`  
{ 13QCM0#  
System.err.println(sMsg); WD\{Sdx:r  
} %b{!9-n}  
} k_a'a)`$6  
 wi9|  
t~M<j| ]k  
/* vv0zUvmT  
**TestMethod.java <=inogf  
*/ 4jz]c"p-  
package NetFox; tbPPI)lu  
+z D'r5  
2:N_c\Vi  
public class TestMethod { ) ,hj7  
jkP70Is  
btF%}<o)  
public TestMethod() 1ZL_;k  
{ ///xx/weblogic60b2_win.exe u W|x)g11a  
try{ 84!4Vz^  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {^f0RGJg9  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v 2GhR*  
SiteFileFetch fileFetch = new SiteFileFetch(bean); |d5L Ifb(  
fileFetch.start(); cA%U  
} /a(zLHyz)  
catch(Exception e){e.printStackTrace ();} 2SJh6U  
9Bk}g50$#  
)/Xrhhx  
} |+:ZO5FaO  
ee_\_"  
oPy zk7{  
public static void main(String[] args) "J5Pwvs-  
{ J3x7i8  
new TestMethod(); W`'|&7~  
} W[>TqT63  
} tKeO+6l  
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