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http断点续传简单实现(java)

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/* Ey_" ~OB  
**SiteFileFetch.java .Si,dc\  
*/ E5)b  
package NetFox; [pl'|B  
import java.io.*; eCN })An  
import java.net.*; =+ytTQc*ot  
fF?z|  
N"8_S0=pw  
public class SiteFileFetch extends Thread { #.it]Nv{  
aa?w:3  
,$+lFv3LE  
SiteInfoBean siteInfoBean = null; //文件信息Bean bu |a0h7e  
long[] nStartPos; //开始位置 ERpnuMb  
long[] nEndPos; //结束位置 l ;JA8o\x  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 crqpV F]1]  
long nFileLength; //文件长度 V=zi >o`   
boolean bFirst = true; //是否第一次取文件 Y,W uBH  
boolean bStop = false; //停止标志 cV 5CaaL  
File tmpFile; //文件下载的临时信息  /<HRwG\w  
DataOutputStream output; //输出到文件的输出流 P/c&@_b  
fIj|4a+  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 7N-w eX  
public SiteFileFetch(SiteInfoBean bean) throws IOException :,Pn3xl  
{ y=`2\L" O  
siteInfoBean = bean; h!&prYx  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); {U!8|(  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); .z 6fv  
if(tmpFile.exists ()) Q7R~{5r>W  
{ ZT,B(#m  
bFirst = false; vg D77  
read_nPos(); j:k[90  
} Q?3Gk%T0[  
else Qk\A c  
{ \=uKHNP?#  
nStartPos = new long[bean.getNSplitter()]; ?*E'^~,H)  
nEndPos = new long[bean.getNSplitter()]; t"k*PA  
} - M[$Zy^  
q8^^H$<Db  
%F!1  
#>%X_o-o23  
} G>wqt@%r9  
twP,cyR  
Fb^:V4<T  
public void run() BlXB7q,  
{ }RmU%IYc  
//获得文件长度 pcYG~pZ9  
//分割文件 IkBei&4F`  
//实例FileSplitterFetch Pm lx8@D  
//启动FileSplitterFetch线程 _acE:H  
//等待子线程返回 _C(m<n  
try{ XLAN Np%E  
if(bFirst) FP;Ccl"s  
{ @r#v[I  
nFileLength = getFileSize(); .Jt[(;  
if(nFileLength == -1) ;\lW5ZX  
{ et,f_fd7v  
System.err.println("File Length is not known!"); x/;buW-  
} ]T;EdK-  
else if(nFileLength == -2) {) Q@c)'  
{ JS*m65e  
System.err.println("File is not access!"); um4yF*3b9  
} 4d8B`Fa9  
else &K/ya7  
{ qjf[zF  
for(int i=0;i<nStartPos.length;i++) } w 5l  
{ dZi(&s  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); '[ C.|)"  
} H2um|6>  
for(int i=0;i<nEndPos.length-1;i++) F{eU";D  
{ G`\f  
nEndPos = nStartPos[i+1]; LUC4=kk4   
} ^j" .  
nEndPos[nEndPos.length-1] = nFileLength; L5#P[cHzz  
} QAvir%Y9Q  
} ]@uE #a:[  
&jsVw)Ue  
7PANtCFb&  
//启动子线程 4g : >[q  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; GlbySD@  
for(int i=0;i<nStartPos.length;i++) dHK`eS$sb  
{ wvbPnf^y  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FI3)i>CnW  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4$*%gL;f^  
nStartPos,nEndPos,i); zgs(Dt;  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /%&2HDA)  
fileSplitterFetch.start(); %n hm  
} c0hwc1kv-  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n@U n  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -C<zF`jO  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (*oL+ef-C  
nEndPos = " + nFileLength); l-ct?T_@  
// fileSplitterFetch[nPos.length-1].start(); _~*,m#uxJ  
N 5i+3&  
h"_~7 jq"  
//等待子线程结束 AwslWkd=  
//int count = 0; \/1<E?Q f  
//是否结束while循环 NGOqy+Ty{f  
boolean breakWhile = false; \hhmVt@@  
]3g?hM6  
EI:w aIr  
while(!bStop) PB#fP_0C  
{ mml<9fbH  
write_nPos(); UN zlN  
Utility.sleep(500); -5T=:2M  
breakWhile = true; iVd.f A  
iVG-_RsKK  
'UMXq~RMe  
for(int i=0;i<nStartPos.length;i++) TZ2=O<Kj  
{ !"<MsoY@  
if(!fileSplitterFetch.bDownOver) 9nH?l{As   
{ < V\I~;  
breakWhile = false; (rkU)Q  
break; wc!onZX5  
} 'JNElXqrv  
} {W]=~*w  
if(breakWhile) =k/IaFg 6w  
break;  b^p"|L  
fH)YFn/  
D<Z p!J1o  
//count++; IdXZoY  
//if(count>4) CMn{LQcC  
// siteStop(); RB+N IoQQ|  
} hWKJ,r%9;  
 nv0]05.4  
t`+'r}=d  
System.err.println("文件下载结束!"); vP !{",>  
} K^ B%/T]d  
catch(Exception e){e.printStackTrace ();} $dA-2e1 0  
} Q",0F{'  
8HRmQ  
e0J6Ae4V[  
//获得文件长度 z,VD=Hnz  
public long getFileSize() LrAT Sq@  
{ Ma+$g1$  
int nFileLength = -1; QK+(g,)_86  
try{ ed:@C?  
URL url = new URL(siteInfoBean.getSSiteURL()); HO[wTB|D]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ' 4E R00  
httpConnection.setRequestProperty("User-Agent","NetFox"); om]4BRe  
<0S,Q+&  
Fr%d}g  
int responseCode=httpConnection.getResponseCode(); (sQr X{~  
if(responseCode>=400) Vo7dAHHL  
{ :_@JA0n  
processErrorCode(responseCode); UQ[B?jc  
return -2; //-2 represent access is error .58qL-iC  
} I8QjKI (  
x ul]m*Z  
IXb}AxB f  
String sHeader; Rcawc Y  
j~FD{%4N  
STglw-TC\  
for(int i=1;;i++) #Jna6  
{ HmZ{L +"  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yB3;  
//Utility.log(in.readLine()); l/Vo-#  
sHeader=httpConnection.getHeaderFieldKey(i); =i(?deR  
if(sHeader!=null) hRq3C1 mR  
{ 2CzaL,je[  
if(sHeader.equals("Content-Length")) AQc,>{Lm  
{ 5bA)j!#)|X  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ki{3IEOr}  
break; ,:%"-`a%  
} ) /v6l  
} >y}M.Mm  
else M{$j  
break; )LdyC`S\c  
} .-JCwnP  
} Q//,4>JKf  
catch(IOException e){e.printStackTrace ();} ?]rPRV  
catch(Exception e){e.printStackTrace ();} VOr1  
/RyR>G!  
?h0X,fl3  
Utility.log(nFileLength); !=y]Sv~h  
rLU/W<F8  
A"aV'~>  
return nFileLength; W;1|+6x  
} Q0\0f  
Qjnd6uv{I  
;P;((2_X9  
//保存下载信息(文件指针位置) Hk7q{`:N  
private void write_nPos() {VP$J"\e  
{ LPwT^zV&N  
try{ 4:7V./" 9  
output = new DataOutputStream(new FileOutputStream(tmpFile));  iL= m{  
output.writeInt(nStartPos.length); [lk'xzE  
for(int i=0;i<nStartPos.length;i++)  `juLQH  
{ ZbT/$\0(6  
// output.writeLong(nPos); 1RKW2RCaW_  
output.writeLong(fileSplitterFetch.nStartPos); :0/q5_t  
output.writeLong(fileSplitterFetch.nEndPos); siTX_`0  
} c,Euv>*`  
output.close(); .@"q$\  
} g!i45-n3gt  
catch(IOException e){e.printStackTrace ();} <jS~ WI@  
catch(Exception e){e.printStackTrace ();} 5~.ZlGd  
} unJ R=~E  
S2>c#BQ  
5VO;s1  
//读取保存的下载信息(文件指针位置) .0G6flD   
private void read_nPos() fgj^bcp-  
{ '<R>E:5  
try{ !6G?zipB  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j&UMjI9[  
int nCount = input.readInt(); NjE</Empb%  
nStartPos = new long[nCount]; v?c 0[+?  
nEndPos = new long[nCount]; }dxDt qb  
for(int i=0;i<nStartPos.length;i++) Bk}><H  
{ /cK%n4l.y  
nStartPos = input.readLong(); IG?'zppjd6  
nEndPos = input.readLong(); JxjI]SF02  
} " v}pdUW  
input.close(); xvNo(>  
} f/kI| Z  
catch(IOException e){e.printStackTrace ();} W- $a Y2  
catch(Exception e){e.printStackTrace ();} 5/QRL\  
} NWfAxkz {/  
?k[p<Uo  
x"4} isp<  
private void processErrorCode(int nErrorCode) \7z^!m  
{ <} jPXEB"  
System.err.println("Error Code : " + nErrorCode); =H8 xSJLh  
} 4gSH(*}  
ICB~_O5  
jEz+1Nl)  
//停止文件下载 @=5qT]%U3J  
public void siteStop() nJ?^?M'F%  
{ L&-hXGx=7  
bStop = true; 0e[d=)XG  
for(int i=0;i<nStartPos.length;i++) \#'TNmS  
fileSplitterFetch.splitterStop(); qi^!GA'5j  
#,(sAj  
]l~V&#i_c  
} Sb".]>^  
} !TAp+b  
//负责部分文件的抓取 B$?qQ|0:=  
**FileSplitterFetch.java XI Jlc~2  
*/ Zs2-u^3&  
package NetFox; I =Wc&1g  
%g]vxm5?  
-xg2q V\c  
import java.io.*; uE=$p)  
import java.net.*; ( #Z`  
xw<OLWW  
B`$L'  
public class FileSplitterFetch extends Thread { +KEkmXZ  
X~ Rl 6/,  
S>q>K"j^!  
String sURL; //File URL HftxS  
long nStartPos; //File Snippet Start Position fU2qrcVu  
long nEndPos; //File Snippet End Position ?@6/Alk  
int nThreadID; //Thread's ID *FR$vLGn  
boolean bDownOver = false; //Downing is over qP*}.Sqk7  
boolean bStop = false; //Stop identical zHfP+(ah  
FileAccessI fileAccessI = null; //File Access interface v=I|O%  
":Edu,6O  
Lh$dzHq  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException  \4ghYQ:  
{ *pzq.#  
this.sURL = sURL; wyxGe<1  
this.nStartPos = nStart; :`vP}I ^  
this.nEndPos = nEnd;  6qo^2  
nThreadID = id; ~9Cz6yF  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i;PL\Er:tX  
} I/x iT  
jx_4B%kzq  
jY!ZkQsVe  
public void run() $mA5@O~C5\  
{ IB9%QW"0  
while(nStartPos < nEndPos && !bStop) T:asm1BC[  
{  17g^ALs  
{}>n{_  
^] p  
try{ 9=dkx^q  
URL url = new URL(sURL); FZpKFsPx  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pL1s@KR  
httpConnection.setRequestProperty("User-Agent","NetFox"); Lp:6 ;  
String sProperty = "bytes="+nStartPos+"-"; >n.z)ZJ  
httpConnection.setRequestProperty("RANGE",sProperty); m:Go-tk  
Utility.log(sProperty); >x:EJV   
fvo<(c#Y#  
gd@p|PsS^  
InputStream input = httpConnection.getInputStream(); |`yZIY_  
//logResponseHead(httpConnection); +$z]w(lbT  
YJ7V`N p  
!$XHQLqF2  
byte[] b = new byte[1024];  ZC^C  
int nRead; }UyQ#U  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3mt%!}S  
{ 6\d X  
nStartPos += fileAccessI.write(b,0,nRead); Md; /nJO~{  
//if(nThreadID == 1) T9y;OG  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZX`J8lZP  
} M"^K 0 .  
yfjXqn[Z4  
iy5R5L 2  
Utility.log("Thread " + nThreadID + " is over!"); w5~i^x  
bDownOver = true; r;cV&T/?  
//nPos = fileAccessI.write (b,0,nRead); R -elIp  
} :_dICxaLZT  
catch(Exception e){e.printStackTrace ();} K3$` Kv>I  
} _EYB 8e  
} FJM;X-UOY  
y)J(K*x/$  
Il~01|3+m  
//打印回应的头信息 ('o&Q_  
public void logResponseHead(HttpURLConnection con) @O3/3vi1  
{ (hZ:X)E>  
for(int i=1;;i++) <ZPZk'53<f  
{ +S{  
String header=con.getHeaderFieldKey(i); "4}wnu6/  
if(header!=null) zDBD.5R;  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ( 76{2  
Utility.log(header+" : "+con.getHeaderField(header)); - HOnB=  
else j^u[F"  
break; +QqH}= M  
} Zy]s`aa  
} ML!9:vz  
{/M\Q@j  
7|D|4!i2Y  
public void splitterStop() \gKdD S  
{ sB*o)8  
bStop = true; MR9/Y:Nm  
} x6yW:tUG5  
, r+"7$  
Z^6#4Q]YC  
} ;( K MGir  
WVL#s?=g  
J 3?Dj  
/* hH4o;0rqJ  
**FileAccess.java Sni=gZK  
*//文件访问(定位,写) # 3.)H9  
package NetFox; *%- ?54B  
import java.io.*; -Ds|qzrN%  
LF=c^9t  
af>3V(7  
public class FileAccessI implements Serializable{ C-#.RI7  
?eWJa  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C6k4g75U2  
RandomAccessFile oSavedFile; ?n*fy  
long nPos; O3_B<Em  
a&5g!;.  
dK # h<q1  
public FileAccessI() throws IOException X ]s"5ju|t  
{ 4]BJ0+|mT  
this("",0);  nP_=GI  
} x0x $  9  
kEAhTh&g*  
zA{8C];~  
public FileAccessI(String sName,long nPos) throws IOException 3q~Fl=|.o  
{ @InJ_9E  
oSavedFile = new RandomAccessFile(sName,"rw"); %Dyh:h   
this.nPos = nPos; Mvof%I  
oSavedFile.seek(nPos); NWISS  
} [ -12]3  
[h", D5  
*)%dXVf  
public synchronized int write(byte[] b,int nStart,int nLen) ?M"HXu  
{ ZlM_ m >,o  
int n = -1; 3}4#I_<$F@  
try{ @&:VKpu\  
oSavedFile.write(b,nStart,nLen); uX0 Bp8P  
n = nLen; p":@>v?  
} )k%M.{&bji  
catch(IOException e) u9}!Gq  
{ \dNhzd#  
e.printStackTrace (); h ]}`@M"  
} :@e\'~7sH  
GN%<"I.  
MgnE-6_c  
return n; w a.f![  
} |uQ[W17^N  
(w2(qT&O  
LhKY}R  
} I =b'j5c  
<UK5eVQn  
Ld~4nc$H8  
/* pX]21&F  
**SiteInfoBean.java ?H0m<jO8~  
*/ \*9Ua/H  
package NetFox; S-P{/;c@  
.nPL2zO  
ylim/`u}6  
public class SiteInfoBean { k!c7a\">{  
Gbx";Y8  
\)GR\~z0h  
private String sSiteURL; //Site's URL @YNGxg~*g  
private String sFilePath; //Saved File's Path #fzw WP  
private String sFileName; //Saved File's Name 7<4xtK`+b  
private int nSplitter; //Count of Splited Downloading File [iXi\Ex  
4g'}h`kh  
TMtI^mkB:  
public SiteInfoBean() LO}z)j~W  
{//nSplitter的缺省值为5 4]u,x`6C  
//default value of nSplitter is 5 w=$'Lt!  
this("","","",5); JP_kQ  
} NCxn^$/+>9  
.]zw*t*  
_M&{^d  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }(cY|  
{ 5])8qb/F  
sSiteURL= sURL; ytob/tc  
sFilePath = sPath; k?n]ZNlT  
sFileName = sName; U>1b9G"_  
this.nSplitter = nSpiltter; mR!rn^<l  
:OX$LCi  
>OTl2F}4 !  
} 0ZT 0  
*CT.G'bQX  
Bj+wayMi  
public String getSSiteURL() PgTDjEo  
{ ktWZBQY  
return sSiteURL; @7]\y7D  
} vQcUaPm\$  
:Ip~)n9t  
b+_hI)T  
public void setSSiteURL(String value) e %&  
{ :=Nb=&lst  
sSiteURL = value; M(NH9EE  
} +yiU@K).0  
[}@n*D$  
p^Agh  
public String getSFilePath() fvO;lA>`  
{ BZ}`4W'  
return sFilePath; %-k(&T3&  
} O68bzi]  
Slo9#26  
)L|C'dJ<k`  
public void setSFilePath(String value) 4^`PiRGt  
{ +{'lZa  
sFilePath = value; v/ eB,p  
} 9Dy)nm^  
{DSyV:   
6G$/NW=L  
public String getSFileName() t+jIHo  
{ /jvO XS\M  
return sFileName; OoE9W  
} <TL])@da  
(26Bs':M~  
Z%KL[R}^w;  
public void setSFileName(String value) 4YBf ~Pp  
{ ~.FnpMDY  
sFileName = value; )4Bwt`VX  
} S'|lU@P Cl  
:82?'aR  
\3L$I-]m  
public int getNSplitter() N:twq&[Y  
{ oO8]lHS?@  
return nSplitter; Z0{f  
} oy`3r5g   
{a[&#Uv  
?{?Vy9'B  
public void setNSplitter(int nCount) d8D yv#gT  
{ >J9IRAm}sc  
nSplitter = nCount; JXlTN[O  
} 8 H,_vf  
} 2V 4`s'  
*>G ^!e.u  
Vn@A]Jx^  
/* Pu1GCr(  
**Utility.java >y&[BB7S6  
*/ bJANZn|H  
package NetFox; H&w(]PDh  
8 f|9W%jt  
$#TID=  
public class Utility { o.p+j  
O.]_Ry\OXA  
 3&O% &  
public Utility() "sdcP8])d  
{ <.;@ksCPW{  
vM5k4%D  
:O5Tr03z  
} G[ ,,L  
?Ozk^#H[  
//线程睡眠 i:MlD5 F  
public static void sleep(int nSecond) l kI8 {  
{ [^h/(a`  
try{ "tqS|ok.  
Thread.sleep(nSecond); unx;m$-c  
} 3S;>ki4(0  
catch(Exception e) muW`pm  
{ Bi'I18<  
e.printStackTrace (); ,oC= {^l{  
} I:r($m  
} 9NJ=~Ub-  
?aP1  
//日志 Iz 1*4@  
public static void log(String sMsg) Sr4dY`V*:z  
{ Uyz;U34 oI  
System.err.println(sMsg); R~U2/6V  
} ]|H]9mys98  
y.L|rRe@P  
Wh#os,U$  
public static void log(int sMsg) ,| $|kO/  
{ 40`9t Xn  
System.err.println(sMsg); l=Vowx.$2f  
} cP/F| uG5  
} MBnK&GS  
pE9aT5 L  
#p11D= @[  
/* s?4%<jz  
**TestMethod.java de3yP,  
*/ J R 8 Z6  
package NetFox; s@*,r@<  
X; e`y:9  
;mCGh~?G  
public class TestMethod { +OV%B .  
l:>qR/|m  
WM~J,`]J  
public TestMethod() Fm-q=3  
{ ///xx/weblogic60b2_win.exe &!3VqHQ`  
try{ `kaR@t  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mtiO7w"M\7  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ' lQ  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3j[w -Lfp  
fileFetch.start(); #n6FQ$l8m  
} *y":@T  
catch(Exception e){e.printStackTrace ();} %fex uy4  
wN/*|?`Z  
G}Qk!r  
} d()zW7}W  
=R"Eb1  
S)Ub/`f{s  
public static void main(String[] args) b |o`Q7Hj  
{  0jip::x  
new TestMethod(); \4]zNV ~x  
} RE(=! 8lGR  
} f4A4  
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