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http断点续传简单实现(java)

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/* EPW4 h/I  
**SiteFileFetch.java `.;U)}Tn  
*/ KK 7}q<&i  
package NetFox; [G brKq(  
import java.io.*; / xv5we~  
import java.net.*; ,JI]Eij^  
#8XmOJ"W3k  
1$DcE>  
public class SiteFileFetch extends Thread { o`,}b1lh  
^nZ=B>Yn2  
lO\HchG zB  
SiteInfoBean siteInfoBean = null; //文件信息Bean WCd: (8B  
long[] nStartPos; //开始位置 F~=kMQO  
long[] nEndPos; //结束位置 &M5v EPR  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 GTB\95j]  
long nFileLength; //文件长度 }],l m  
boolean bFirst = true; //是否第一次取文件  gwIR3u  
boolean bStop = false; //停止标志 ,62~u'hR5  
File tmpFile; //文件下载的临时信息 ^}2!fRKAmo  
DataOutputStream output; //输出到文件的输出流 zq + 2@"q  
 I wj[ ^  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) L[44D6Vg  
public SiteFileFetch(SiteInfoBean bean) throws IOException E[t[R<v,P!  
{ VEa"^{,w  
siteInfoBean = bean; :C^{Lc  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); [BdRx`  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ?IeBo8  
if(tmpFile.exists ()) t$qIJt$  
{ PJ:!O?KVq  
bFirst = false; '9]?jkl  
read_nPos(); DCa[?|Y  
} VS4Glx73  
else .qe+"$K'n  
{ ;^s|n)F#c  
nStartPos = new long[bean.getNSplitter()]; \x$`/  
nEndPos = new long[bean.getNSplitter()]; $-^& AKc  
} #3ZAMV  
fqbWD)L]  
:!Z|_y{b  
FLJ&ZU=s  
} ~c&sr5E  
prM)t8SE  
\aPH_sf,  
public void run() A%EhRAy  
{ ,y"vf^BE.  
//获得文件长度 +EA ")T<l  
//分割文件 F%zMhX'AG  
//实例FileSplitterFetch y)L X?d  
//启动FileSplitterFetch线程 _GY2|x2c  
//等待子线程返回 cb'Y a_  
try{ s8:epcL`A  
if(bFirst) Msvs98LvW  
{ ]~$@x=p2e  
nFileLength = getFileSize(); ~:,}?9  
if(nFileLength == -1) k]gPMhe  
{ U`N?<zm<oO  
System.err.println("File Length is not known!"); e`a4Gr  
} <x$nw'H9  
else if(nFileLength == -2) kqZRg>1A  
{ f3,LX]zKA  
System.err.println("File is not access!"); !m=Js"  
} GYy8kp84  
else w9u|E46  
{ ,c&t#mu*0  
for(int i=0;i<nStartPos.length;i++) @lM-+q(tl  
{ B]hRYU  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); r]}6iF.  
} 3 u=\d)eq  
for(int i=0;i<nEndPos.length-1;i++) ~%tVb c  
{ (e_p8[x  
nEndPos = nStartPos[i+1]; VxOWv8}|  
} "Cvr("'O  
nEndPos[nEndPos.length-1] = nFileLength; ;L",K?6#  
} |j/Y#.k;{0  
} _)LXD,LA  
F~fN7<9R  
Ht43G_.j  
//启动子线程 }X])055S  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O|Vc  
for(int i=0;i<nStartPos.length;i++) D\ZH1C!d  
{ Tw%1m  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z;u3G4XlF  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w?3ww7yf`  
nStartPos,nEndPos,i); _"H\,7E  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &RuTq6)r  
fileSplitterFetch.start(); $uwz` N:  
} b'FTy i  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m0 W3pf  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lZkJ<*z#  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?t}s3P!Q3w  
nEndPos = " + nFileLength); ]) v61B  
// fileSplitterFetch[nPos.length-1].start(); C_ ;nlG6  
B<myt79F_[  
"tO m  
//等待子线程结束 %Y/;jC Y  
//int count = 0; bFG?mG:  
//是否结束while循环 {[bpvK  
boolean breakWhile = false; pi70^`@'B  
9I5AYa?  
L|D9+u L  
while(!bStop) Q|VBH5}1O  
{ : maBec)  
write_nPos(); qb=%W  
Utility.sleep(500); ?&qQOM~b-\  
breakWhile = true; 9%R"(X)  
s9Tn|Pm+!\  
?|NsaW  
for(int i=0;i<nStartPos.length;i++) v0!(&g 3Sd  
{ | h"$  
if(!fileSplitterFetch.bDownOver) [SKDsJRPP  
{ eMEKR5*-O  
breakWhile = false; 1f"}]MbLR  
break; [".94(qs  
} 5Uhxl^c  
} 8.%wnH  
if(breakWhile) VqD_FS;E  
break; f]sR4mhO  
RV]QVA*i  
U![$7k>,pr  
//count++; oFt_ yU-  
//if(count>4) h1B_*L   
// siteStop(); 8Bc2?NI=   
} xHx_! )7  
%y_pF?2@q  
W7.RA>  
System.err.println("文件下载结束!"); l  ~xXy<  
} a3:45[SO4e  
catch(Exception e){e.printStackTrace ();} D;48VK/Q  
} gQ{<2u  
'%+LQ"Bp  
Cnc=GTR i  
//获得文件长度 zLxuxf~4@  
public long getFileSize() Uw5&.aqn.b  
{ 7bGOE_r  
int nFileLength = -1; a>6M{C@pd  
try{ Mx# P >.  
URL url = new URL(siteInfoBean.getSSiteURL()); n Jz*}=  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V'za,.d-  
httpConnection.setRequestProperty("User-Agent","NetFox"); xrlyph5mE  
(Xz q(QV  
z#n+iC$9  
int responseCode=httpConnection.getResponseCode(); SEu:31k{o  
if(responseCode>=400) pp#!sRUKPV  
{ %k"hzjXAw  
processErrorCode(responseCode); &liFUP?   
return -2; //-2 represent access is error 1Qjc*+JzO.  
} vUL@i'0&o  
S@ y! 0,  
)Fqtb;W=  
String sHeader; x a\~(B.  
F7=\*U  
"*c&[ALw  
for(int i=1;;i++) t82*rC IB{  
{ XfEp_.~JM  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y+7+({w<  
//Utility.log(in.readLine()); R +U*]5~R  
sHeader=httpConnection.getHeaderFieldKey(i); LF (S"Of  
if(sHeader!=null) ,#^2t_c/  
{ 1b7?6CqV  
if(sHeader.equals("Content-Length")) P=E10  
{ TL -AL tG  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z>=;Xe8P8n  
break; sUk n.g!  
} .G<Or`K^i  
} l;h -`( 11  
else !WB3%E,I  
break; >*|Eyv_  
} *Hv d  
} Pc+,iK>  
catch(IOException e){e.printStackTrace ();} or)fx/%h  
catch(Exception e){e.printStackTrace ();} UpiZd/K  
IG%x(\V-e  
O!F"w !5@  
Utility.log(nFileLength); FELW?Q?k  
i!<(R$ Lo  
a94 nB  
return nFileLength; ep l1xfr  
} O "Aeg|  
-O@/S9]S)  
6hFs{P7  
//保存下载信息(文件指针位置) "`pg+t&  
private void write_nPos() zR=g<e1xe  
{ bDegIW/'w  
try{ ~ihi!u%~}  
output = new DataOutputStream(new FileOutputStream(tmpFile)); XNBzA3W  
output.writeInt(nStartPos.length); # ?u bvSdU  
for(int i=0;i<nStartPos.length;i++) ?]}=4  
{ ;>]dwsA*P  
// output.writeLong(nPos); Z ]OX6G  
output.writeLong(fileSplitterFetch.nStartPos); 0h('@Hb.K#  
output.writeLong(fileSplitterFetch.nEndPos); 4i29nq^n  
} y7z ,I  
output.close(); LG?b]'#  
} bvJ*REPL ?  
catch(IOException e){e.printStackTrace ();} n*~#]%4  
catch(Exception e){e.printStackTrace ();} v=IcVHuf  
} '?$< k@mJW  
I wu^@  
|g\CS4$  
//读取保存的下载信息(文件指针位置) K=P LOC5  
private void read_nPos() Ml_!)b  
{ (+TL ]9P  
try{ Wl,I%<&j}  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g(F2IpUm/  
int nCount = input.readInt(); Lf Y[Z4  
nStartPos = new long[nCount]; "?J f#  
nEndPos = new long[nCount]; D]V&1n  
for(int i=0;i<nStartPos.length;i++) AUaupNN  
{ $BOIa  
nStartPos = input.readLong(); <1U *{y  
nEndPos = input.readLong(); Hxj8cX UF|  
} /\pUA!G)BD  
input.close(); )VG_Y9;Xk:  
} H .sfM   
catch(IOException e){e.printStackTrace ();} hSk  
catch(Exception e){e.printStackTrace ();} S~y.>X3"P  
} z+?48 }  
Ap}`Q(.  
_`9WNJiL  
private void processErrorCode(int nErrorCode) 9H%ixBnM  
{ =mxj2>,&  
System.err.println("Error Code : " + nErrorCode); I=8MLv  
} "N=q>jaX  
tqU8>d0^  
z)*\njYe  
//停止文件下载 1| xKb (_l  
public void siteStop() OJLyqncw  
{ YgkQF0+  
bStop = true; ksqb& ux6  
for(int i=0;i<nStartPos.length;i++) w6l56 CB`  
fileSplitterFetch.splitterStop(); v XR27  
`u8=~]rblj  
x=1Sbs w{  
} pzDz@lAwR  
}  Z Mf,3  
//负责部分文件的抓取 O$Dj_R#  
**FileSplitterFetch.java T%2%*oa  
*/ VmTgD96  
package NetFox; & y7~  
dQAo~] B  
2-wgbC5  
import java.io.*; 6c[ L*1  
import java.net.*; Sr6?^>A@t  
bB.Yq3KI  
=ZARJ40L  
public class FileSplitterFetch extends Thread { 3>^S6h}o  
u$1^=  
5S #6{Y =  
String sURL; //File URL 7"k\i=  
long nStartPos; //File Snippet Start Position I#CS;Yh95  
long nEndPos; //File Snippet End Position N*Xl0m(Q  
int nThreadID; //Thread's ID jx];=IC3tt  
boolean bDownOver = false; //Downing is over %U&ztvR0C  
boolean bStop = false; //Stop identical ]Ai!G7s8P  
FileAccessI fileAccessI = null; //File Access interface YZ5[# E@l  
6IL-S%EGK1  
I8:G:s:  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'i8?]` T  
{ V}t8H  
this.sURL = sURL; J2$ =H1-  
this.nStartPos = nStart; R!_1*H$  
this.nEndPos = nEnd; 1++Fs  
nThreadID = id; atfK?VK#  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ; 5!8LmZ0#  
} ;:ocU?  
9!vimu)  
G4,BcCPQ  
public void run() `AELe_  
{ ch0x*[N@  
while(nStartPos < nEndPos && !bStop) DOW Z hD  
{ T;B/ Wm!x  
VD2o#.7*eu  
}+ TA+;  
try{ uulzJbV,K  
URL url = new URL(sURL); O>arCr=H  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fH;lh-   
httpConnection.setRequestProperty("User-Agent","NetFox"); ]+AgXUrbOD  
String sProperty = "bytes="+nStartPos+"-"; 4{ exv  
httpConnection.setRequestProperty("RANGE",sProperty); ; HjT  
Utility.log(sProperty); 2v1dSdX,W  
6Nz S<  
#4?:4Im#  
InputStream input = httpConnection.getInputStream(); U{-[lpd  
//logResponseHead(httpConnection); c}#(,<8X  
@-}!o&G0  
Z+! 96LR  
byte[] b = new byte[1024]; q3Y49d  
int nRead; _1HEGX\  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !o/;"'&E  
{ Yk#$-"c/a  
nStartPos += fileAccessI.write(b,0,nRead); l)91v"vJ  
//if(nThreadID == 1) VV=6v;u`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]hA]o7 k  
} LfG$?<}hR  
Kl+4A}Uo  
~2?UEv6  
Utility.log("Thread " + nThreadID + " is over!"); q|R$A8)L.  
bDownOver = true; 4S,/Z{ J.  
//nPos = fileAccessI.write (b,0,nRead); vTYgWR,h  
} F[U0TP@&*  
catch(Exception e){e.printStackTrace ();} 29h_oNO  
} fuA 8jx  
}   [IW6F  
ZfIeq<8 _  
B7BikxUa  
//打印回应的头信息 Ty"=3AvRLV  
public void logResponseHead(HttpURLConnection con) k.w}}78N2N  
{ U7Pn $l2!  
for(int i=1;;i++) 97SG;,6  
{ !fG`xZ~  
String header=con.getHeaderFieldKey(i); V@1K  
if(header!=null) >oc&hT  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v`u>; S_  
Utility.log(header+" : "+con.getHeaderField(header)); 7)v`l1  
else N`i`[ f  
break; Q##L|*Qy  
} STQ~mFs"  
} {_*$X  
>{kPa|  
~qm u?5  
public void splitterStop() v D4<G{  
{ 'O]Ja-  
bStop = true; t%>x}b"2T  
} U})Z4>[bvt  
o[CjRQY]P  
I~I$/j]e`  
} ]%/a'[  
<\5Y~!)  
\%:]o-+"I  
/* >iB-gj}>X  
**FileAccess.java b'~IFNt*^  
*//文件访问(定位,写) yzmwNsu  
package NetFox; wPU<jAQyp  
import java.io.*; <S%kwS  
@IwVR  
SB`"%6  
public class FileAccessI implements Serializable{ Ty>g:#bogI  
|MXv  w6P  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4 jeUYkJUM  
RandomAccessFile oSavedFile; Pxm~2PAm  
long nPos; o+Kh2;$)  
;P4tqY@  
ym)`<[T  
public FileAccessI() throws IOException Z ]WA-Q6n  
{ Sk,9<@  
this("",0); 8q& *tpE  
} XZ8;Ow=  
g?caE)  
)<1}`9G  
public FileAccessI(String sName,long nPos) throws IOException |K6hY-uC  
{ H/6GD,0  
oSavedFile = new RandomAccessFile(sName,"rw"); pu*vFwZ  
this.nPos = nPos; wUz)9n 6j  
oSavedFile.seek(nPos); uua1_# a  
} *!y.!v*  
lhA<wV1-9G  
zx{O/v KG  
public synchronized int write(byte[] b,int nStart,int nLen) r'ydjy  
{ 5=.EngG  
int n = -1; q#~]Hp=W5  
try{ Tse Pdkk  
oSavedFile.write(b,nStart,nLen); Wd_cNR\  
n = nLen; #D{//P|;  
} C=/nZGG  
catch(IOException e) R?Or=W)i  
{ ~:%rg H  
e.printStackTrace (); |cBpX+D  
} ,\K1cW~U5  
#}A >B  
z<F.0~)jb  
return n; Ng} AEAFp  
} Q`}n; DV  
oGLSk (T&I  
jF\J+:5M  
} k+S 6)BQ7U  
.baS mfc  
z AxwM-`  
/* ZK[S'(6q  
**SiteInfoBean.java ~4mgYzOmD`  
*/ Dn?P~%  
package NetFox; kE".v|@  
xe: D7  
S{NfU/: dL  
public class SiteInfoBean { %L./U$  
%XqLyeOS  
(r^IW{IndX  
private String sSiteURL; //Site's URL +*Cg2`  
private String sFilePath; //Saved File's Path eD, 7gC-  
private String sFileName; //Saved File's Name XRI1/2YA  
private int nSplitter; //Count of Splited Downloading File Nky%v+r  
T] nZ3EZ  
-NVk>ENL4  
public SiteInfoBean() [PrR 3 0:  
{//nSplitter的缺省值为5 $2^V#GWo  
//default value of nSplitter is 5 A]{8 =  
this("","","",5); V&_5q`L  
} ~`MGXd"o  
fwIZr~l  
E YUr.#:  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s&lZxnIjc  
{ %t\`20-1<  
sSiteURL= sURL; hSD)|  
sFilePath = sPath; 0=s+bo1  
sFileName = sName; / vge@bsE  
this.nSplitter = nSpiltter; 79a{Zwdd9j  
Ah &D5,3  
QH4nb h4  
} )E^4\3 ^:  
>;QkV6i7  
[6 !/  
public String getSSiteURL() {61NLF\0H  
{ +6f5uMKUvs  
return sSiteURL; ''wWw(2O  
} r}QW!^F  
;=6 ++Oq  
8@/]ki `>  
public void setSSiteURL(String value) v^[Ny0cM  
{ ,KIa+&vJW@  
sSiteURL = value; 0ldde&!p  
} g?i_10Xlp  
`a2Oj@jP  
q[q#cY:0  
public String getSFilePath() K I$?0O  
{ |zvxKIW;wd  
return sFilePath; y3$' gu|  
} \x x<\8Qr_  
qEf )TW(  
PF!Q2t5c3  
public void setSFilePath(String value) f b_tda",}  
{ eF}Q8]da  
sFilePath = value; X<(h)&E  
} k KL^U  
(J<@e!@NE  
mw`%xID*  
public String getSFileName() \J-O b  
{ r#]gAG4t\  
return sFileName; uHQJ&  
} 42Vy#t/HC  
*s?&)][  
8{JTR|yB  
public void setSFileName(String value) : O t\l  
{ h.4;-&  
sFileName = value; oRy?Dx+H  
} & HphE2 h  
dlK#V)  
%o#D"  
public int getNSplitter()  X\ \\RCp  
{ N(}7M~m>  
return nSplitter; &N*S   
} 0wZLkU_(  
D Z ~|yH  
5HL JkOV5  
public void setNSplitter(int nCount)  h:#  
{ .rG Rdb  
nSplitter = nCount; Ua V9T:)x  
} Nf0b?jn-  
} /n?5J`6  
**-%5 ~  
?$;_a%v6  
/* cGsxfwD  
**Utility.java 6l [T Q  
*/ lbT<HWzNH  
package NetFox; %MbjKw  
Lvv`_  
w*#k&N[X  
public class Utility { WqY:XE+?\  
;csAhkf:S  
xYM/{[  
public Utility() ^lRXc.c z  
{ x}N+vK   
fPK|Nw]b  
&!/L^Y*+  
} Ax0u \(p<^  
qg:1  
//线程睡眠 N_q7ip%z  
public static void sleep(int nSecond) pR 1v^m|  
{ Wz:MPdz3(  
try{ k%NY,(:(  
Thread.sleep(nSecond); -hp,O?PM  
} 8,dCx}X  
catch(Exception e) 0NpxqeIDY  
{ )/bt/,M&}  
e.printStackTrace (); S][: b  
} : [aUpX=  
} A+Y>1-=JO  
Lkk'y})/  
//日志 yn!LJT[~2  
public static void log(String sMsg) c !P9`l~MQ  
{ t ~U&a9&Z  
System.err.println(sMsg); fn#b3ee  
} dWD9YIYf  
$CL=M  
Yq`r>g  
public static void log(int sMsg) lJKhP  
{ X"iy.@7  
System.err.println(sMsg); &}:Hp9n  
} 79:x>i=  
} fRaVY`|wK  
^"6xE nA]  
'n!;7*  
/* U G^6I5  
**TestMethod.java a/_sL(F{  
*/ ] =>vv;L  
package NetFox; ;?zb (2  
 >?U (w<  
O~fRcf:Q  
public class TestMethod { 0~Yg={IKhK  
bi KpV? Dp  
I7BfA,mZ7  
public TestMethod() /o8`I m   
{ ///xx/weblogic60b2_win.exe [^ 7^&/0  
try{ Ik;~u8j1e  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4X#>;  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Pm+H!x,  
SiteFileFetch fileFetch = new SiteFileFetch(bean); )]>=Uo  
fileFetch.start(); ]Z<{ ~  
} s'~_pP  
catch(Exception e){e.printStackTrace ();} 2c8,H29  
z %+?\.oH  
lOd[8|/  
} N ?V5gi  
^>g+:?x  
y<)Lr}gP  
public static void main(String[] args) JkQ4'$:  
{ ! ~&X1,l1*  
new TestMethod(); gA~Ih  
} oPzt1Y  
} fcJ#\-+E  
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