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http断点续传简单实现(java)

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/* uy/y wm/?=  
**SiteFileFetch.java X^zYQ6t  
*/ Xzl KP;r0  
package NetFox; 1<xcMn0et  
import java.io.*;  28nmQ  
import java.net.*; \\=.6cg<K  
u5Qp/ag?N  
>f&xJq  
public class SiteFileFetch extends Thread { F\>oxttS1  
cyW;,uT)D  
Y)$52m5rM  
SiteInfoBean siteInfoBean = null; //文件信息Bean \Ut6;  
long[] nStartPos; //开始位置 ,LhE shf  
long[] nEndPos; //结束位置 ~O \}/I28  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 pG/ NuImA  
long nFileLength; //文件长度 C&=x3Cz  
boolean bFirst = true; //是否第一次取文件 g[/^cJHQ  
boolean bStop = false; //停止标志 's)fO#  
File tmpFile; //文件下载的临时信息 %$Aqbd  
DataOutputStream output; //输出到文件的输出流 82lr4  
r=h8oUNEJ*  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) TbOJp  
public SiteFileFetch(SiteInfoBean bean) throws IOException M]c7D`%s  
{ ]Z _$'?f  
siteInfoBean = bean; +H7y/#e+3  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 4[`[mE18.  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); YU&4yk lE  
if(tmpFile.exists ()) )AOPiC$jL  
{ t)LU\!  
bFirst = false; brntE:  
read_nPos(); +Y7Pg'35  
} ji }#MBac  
else 'f 3HKn<L  
{ L^lS^P  
nStartPos = new long[bean.getNSplitter()]; ~L~]QN\3  
nEndPos = new long[bean.getNSplitter()]; [6H}/_nD  
} hGvqT,'  
ei@3,{~5  
j~epbl)pC  
[eyb7\#   
} L/BHexOB  
KGu= ;  
Vc|NL^  
public void run() 7{-@}j`  
{ V7:\q^$  
//获得文件长度 Q\|18wkW  
//分割文件 Rb#/qkk/  
//实例FileSplitterFetch 0pD[7~^o  
//启动FileSplitterFetch线程 /jR8|sb  
//等待子线程返回 AP0|z  
try{ Hq?&Qo  
if(bFirst) Tv\HAK<N  
{ QWw"K$l  
nFileLength = getFileSize(); vO]J]][  
if(nFileLength == -1) >60"p~t  
{ `y2ljIWJ  
System.err.println("File Length is not known!"); !N1J@LT5h  
} Atd1qJ  
else if(nFileLength == -2) ]U[&uymax  
{ !Av1Leb9$  
System.err.println("File is not access!"); t@)my[!  
} VD/&%O8n  
else <7^Kt7k  
{ LJWTSf"f?  
for(int i=0;i<nStartPos.length;i++) ")ED)&e  
{ j7}lF?cJ2  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); zw]3Vg{T  
} p.C1nh  
for(int i=0;i<nEndPos.length-1;i++) jn$j^ 51`C  
{ '00J~j~  
nEndPos = nStartPos[i+1]; Ff<)4`J  
} akC>s8tqlA  
nEndPos[nEndPos.length-1] = nFileLength; :CTL)ad2  
} &DLhb90  
} $6!i BX@  
IBET'!j4"  
O: JPJ"!  
//启动子线程 ({e7U17[#  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (;UP%H>  
for(int i=0;i<nStartPos.length;i++) DWrbp  
{ 4.Z(:g  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TV=c,*TV  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,d cg?48  
nStartPos,nEndPos,i); [D[D`gpjA  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Cw#V`70a  
fileSplitterFetch.start(); Pbe7SRdr^  
} bMmra.x4L  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l3p3tT3+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5 `=KyHi:b  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h<Wg3o  
nEndPos = " + nFileLength); b[srG6{ &  
// fileSplitterFetch[nPos.length-1].start(); 76u{!\Jo/{  
H&bh<KPMh  
W-XpJ\_  
//等待子线程结束 X+iK<F$  
//int count = 0; g$w6kz_[  
//是否结束while循环 ~ziexZ=N  
boolean breakWhile = false; WNF9#oN|oT  
:l"dYfl  
kA^A mfba  
while(!bStop) $<OhGk-  
{ v[&'k\  
write_nPos(); fHfY}BQS  
Utility.sleep(500); "8HE^Po/pn  
breakWhile = true; G),db%,X2  
e4[) WNR  
Qq3fZ=  
for(int i=0;i<nStartPos.length;i++) %v4ZGtKC@  
{ I4il R$jg  
if(!fileSplitterFetch.bDownOver) S}7>RHe  
{ kcS6_l  
breakWhile = false; GN%(9N'W  
break; O2v.  
} "EH,J  
} 2xTT)9Tq*  
if(breakWhile) .pvxh|V  
break; "HC)/)Mv@  
_M5Xk?e=  
U3F3((EYJ  
//count++; J^ ={}  
//if(count>4) zu<3^=3  
// siteStop(); hZN<Yd8:  
} /s[DI;M$o  
'qy#)F  
[ /ohk&  
System.err.println("文件下载结束!"); /6U 4S>'(  
} / Z!i;@Wf  
catch(Exception e){e.printStackTrace ();} o:UXPAj  
} ]0/p 7N14  
X/+OF'po  
a+?~;.i~  
//获得文件长度 Ro r2qDF  
public long getFileSize() d+}kg  
{ yVS\Q,:J9  
int nFileLength = -1; BXhWTGiG  
try{ p4> ,Fwy2  
URL url = new URL(siteInfoBean.getSSiteURL()); )#`H."Z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -_~)f{KN@  
httpConnection.setRequestProperty("User-Agent","NetFox"); rkYjq4Z@  
g:gB`8w?  
{$fsS&aPg  
int responseCode=httpConnection.getResponseCode(); QIV%6q+*R  
if(responseCode>=400) >;nS8{2o  
{ HomN/wKh  
processErrorCode(responseCode); Pp_V5,i\  
return -2; //-2 represent access is error ',mW`ZN  
} N[k<@Q?*a  
hz)9"B\S  
!k<:k "7  
String sHeader; 8(xw?|D7  
Z2p> n`D  
oJY[{-qW  
for(int i=1;;i++) 8A{6j  
{ FA$zZs10\  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nyhMnp#<  
//Utility.log(in.readLine()); ,7,;twKz  
sHeader=httpConnection.getHeaderFieldKey(i); O9]\Q@M.  
if(sHeader!=null) dr })-R  
{ c> G@+  
if(sHeader.equals("Content-Length")) 2Q ayM?k8  
{ PZM42"[&  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :oa9#c`L  
break; Dip*}8$o(w  
} &" h]y?Q  
} Alz~-hqQ  
else vA-PR&  
break; BaL]mIx  
} 8wIK:   
} F?4Sz#  
catch(IOException e){e.printStackTrace ();} cZ< \  
catch(Exception e){e.printStackTrace ();} e4.&aIC[  
cY{Nos  
y\[r(4h  
Utility.log(nFileLength); xm^95}80yh  
mm,lhIh  
pm]fQ uq  
return nFileLength; ?`P2'i<b  
} rn" pKUd  
yQ[u3tI  
1K[(ou'rl  
//保存下载信息(文件指针位置) D4Sh9:\  
private void write_nPos() nem@sB;v#  
{ dlD}Ub  
try{ DuNcX$%%  
output = new DataOutputStream(new FileOutputStream(tmpFile)); IZ~.{UQ  
output.writeInt(nStartPos.length); B8~= RmWLl  
for(int i=0;i<nStartPos.length;i++) pFIecca w  
{ #nEL~&  
// output.writeLong(nPos); 6tdI6  
output.writeLong(fileSplitterFetch.nStartPos); J}@GKNm  
output.writeLong(fileSplitterFetch.nEndPos); Yx1 D)  
} :s*>W$Wp4  
output.close(); se,Z#H  
} &O tAAE  
catch(IOException e){e.printStackTrace ();} &jm[4'$ *z  
catch(Exception e){e.printStackTrace ();} 9#@Zz4Ww  
} Z[} $n-V  
afm_Rrg[  
z5EVG  
//读取保存的下载信息(文件指针位置) K0<yvew  
private void read_nPos() 9^zx8MRXd  
{ :_H>SR:  
try{ mo9$NGM&}  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0w3b~RJ  
int nCount = input.readInt(); ou6j*eSN  
nStartPos = new long[nCount]; a8JN19}D  
nEndPos = new long[nCount]; j9xXKa5  
for(int i=0;i<nStartPos.length;i++) ./.=Rw  
{ s.y}U5Ty?P  
nStartPos = input.readLong(); 1nB@zBQu -  
nEndPos = input.readLong(); 3!Bj{;A  
} *V|zx#RN  
input.close(); p&5S|![\  
} !K\itOEP-  
catch(IOException e){e.printStackTrace ();} AbZ:(+@cP  
catch(Exception e){e.printStackTrace ();} 0N VI +Z$  
} /{we;Ut=g  
-+P7:4/  
HRHrSf7  
private void processErrorCode(int nErrorCode) O+FBQiv  
{ /"MJkM.~E  
System.err.println("Error Code : " + nErrorCode); ;+%Z@b%  
} \7 Mq $d  
la702)N{  
oD,C<[(p  
//停止文件下载 'w6hW7"L  
public void siteStop() D3.VXuKn6  
{ pqq?*\W&[v  
bStop = true; [; @):28"  
for(int i=0;i<nStartPos.length;i++) x@Vt[}e  
fileSplitterFetch.splitterStop(); ~04[KG  
\G3!TwC%  
N 8}lt  
} o^PuhVu  
} CWvlr nv  
//负责部分文件的抓取 R&!]Rl9hf  
**FileSplitterFetch.java ^j iE9k)  
*/ 4:`[qE3  
package NetFox; I>Y{>S  
"Q?_ EEn  
m&cvU>lC  
import java.io.*; DZP*x  
import java.net.*; >[P%Ty);  
[` 9^QEj  
yM|g|;U  
public class FileSplitterFetch extends Thread { Nm"<!a<F  
InN{^uN  
2_N/wR#=&  
String sURL; //File URL K @C4*?P  
long nStartPos; //File Snippet Start Position , QA9k$`  
long nEndPos; //File Snippet End Position ',#   
int nThreadID; //Thread's ID )-#i8?y3C  
boolean bDownOver = false; //Downing is over 6Ty 3e|do  
boolean bStop = false; //Stop identical 0@v 2*\D#  
FileAccessI fileAccessI = null; //File Access interface p}BGw:=  
Pl?}>G  
Z+,CL/  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uAT/6@  
{ ZR6&AiL(Bj  
this.sURL = sURL; 94YA2_f;  
this.nStartPos = nStart; ETg{yBsp  
this.nEndPos = nEnd; L?Tu)<Mn  
nThreadID = id; `Jqf**t  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F~'sT}A*  
} FR(QFt!g  
,@479ZvvR3  
Onyh1  
public void run() i=V-@|Z  
{ J7Sx!PQ  
while(nStartPos < nEndPos && !bStop) [!Ao,rt?Vg  
{ s"N\82z)  
| F8]Xnds  
IF e+ B"  
try{ ;xI0\a7  
URL url = new URL(sURL); Y=|CPE%V  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G4O3h Y.`  
httpConnection.setRequestProperty("User-Agent","NetFox"); }Wqtip:L  
String sProperty = "bytes="+nStartPos+"-"; s*eyTm  
httpConnection.setRequestProperty("RANGE",sProperty); +dJ&tuL:S  
Utility.log(sProperty); &AJUY()8  
{H'X)n$  
\D ^7Z97  
InputStream input = httpConnection.getInputStream(); Z"]xdOre  
//logResponseHead(httpConnection); 1j+eD:d'  
nqrDT1b**  
N?zV*ngBS  
byte[] b = new byte[1024]; _=6vW^ s  
int nRead; z41D^}b  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n}f3Vrl  
{ l -XnB   
nStartPos += fileAccessI.write(b,0,nRead); -&$%|cyThQ  
//if(nThreadID == 1) |Cu1uwy  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _E&U?>g+  
} 'Z y{mq\  
g4i #1V=  
|K6nOX!i  
Utility.log("Thread " + nThreadID + " is over!"); G$|G w  
bDownOver = true; *XHj)DC;  
//nPos = fileAccessI.write (b,0,nRead); 5R)[Ou.  
} {rz>^  
catch(Exception e){e.printStackTrace ();} 'r6cVBb}  
} s* @QT8%  
} p0   
} !Xf&c{7{  
QP'qG@j[:  
//打印回应的头信息 FX cc1X/  
public void logResponseHead(HttpURLConnection con) . c#90RP  
{ *Gf&q  
for(int i=1;;i++) 3Sk5I%  
{ ~ 0av3G  
String header=con.getHeaderFieldKey(i); $tEdBnf^ca  
if(header!=null) e#K rgUG  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y(V&z"wk[  
Utility.log(header+" : "+con.getHeaderField(header)); YcPKM@xo  
else ]Qh[%GD  
break; 6Q?BwD+>  
} C+DG+_%V*S  
} SlR7h$r'  
QziN]  
O}e|P~W  
public void splitterStop() hkkF1 h  
{ X >3iYDe  
bStop = true; | pF5`dX  
} !Jk(&.  
i-|/2I9%  
]r"31.w(  
} ~W2:NQ>i  
#( $k 3OA  
@?'t@P:4  
/* &19l k   
**FileAccess.java 2,rY\Nu_  
*//文件访问(定位,写) A9NOeE  
package NetFox; Tnzco  
import java.io.*; 8XLxT(YFIs  
n ;Ql=4  
t-3v1cv"  
public class FileAccessI implements Serializable{ Z'7 c^c7_  
\] tq7  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p.6$w:eV  
RandomAccessFile oSavedFile; n's2/9x  
long nPos; IKNFYe[9e  
DLwC5Iir  
s!8J.hD'I  
public FileAccessI() throws IOException S3%.-)ib  
{ d A_S"Zc  
this("",0); tJ(c<:zD  
} hP'~  
*7:u-}c!  
u|_I Twk  
public FileAccessI(String sName,long nPos) throws IOException N7RG5?  
{ 3&drof\{  
oSavedFile = new RandomAccessFile(sName,"rw"); @p9e:[  
this.nPos = nPos; ZuF4N=;  
oSavedFile.seek(nPos); ,d9%Ce.$2  
} ,H#qgnp  
!`O_VV`/@  
w@ gl  
public synchronized int write(byte[] b,int nStart,int nLen) >#"jfjDuR  
{ V7K tbL#  
int n = -1; j. ks UJ  
try{ X:xC>4]gG'  
oSavedFile.write(b,nStart,nLen); z[0LU]b<  
n = nLen; Q KcF1?  
} MA/"UV&M(  
catch(IOException e) <{-(\>f!9  
{ B $ y44  
e.printStackTrace (); i 5 >J  
} 4z-,M7iP  
clR?< LO  
V1CSXY\2  
return n; &<fRej]v  
} 5tgILxSK  
PJSDY1T  
\@ WsF$  
} *`S)@'@:(  
C>k;MvqO  
j]ln :?\  
/* yp^[]Mz=  
**SiteInfoBean.java 2EqsfU* I  
*/ {'=Nb 5F  
package NetFox; >zfZw"mEP  
E |GK3/  
 n_xa)  
public class SiteInfoBean { TYJnQ2m  
C9z~)aL}7  
YjIED,eRv  
private String sSiteURL; //Site's URL _/z)&0DO  
private String sFilePath; //Saved File's Path cV=_G E  
private String sFileName; //Saved File's Name yTq(x4]  
private int nSplitter; //Count of Splited Downloading File xj00eL  
[-:<z?(n4  
3>@qQ_8%~  
public SiteInfoBean() \$~oH3m&  
{//nSplitter的缺省值为5 MLv.v&@S  
//default value of nSplitter is 5 G|6|;   
this("","","",5); zoJkDr=jn  
} "6*Kgf2G  
xJH9qc ME  
q$u\ q.  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l~Wk07r3  
{ bh;b` 5  
sSiteURL= sURL; i6g[E 4nk  
sFilePath = sPath; Cf1wM:K|8  
sFileName = sName; ixJ20A7  
this.nSplitter = nSpiltter; = "hY{RUa  
eI=Y~jy  
yY@ s(:  
} jO3u]5}.6  
oN6*WN tJ  
(h@yA8>n  
public String getSSiteURL() X5oW[  
{ l]kl V+9t  
return sSiteURL; 2Fp]S a  
} J:-TINeB  
v YmtpKNj%  
k.%W8C<Pa  
public void setSSiteURL(String value) +q_lYGTiO  
{ zs]/Y2  
sSiteURL = value; <}Wy;!L  
} ,w/mk$v  
%_@5_S  
<1 1Tqb  
public String getSFilePath() k4AE`[UE  
{ t ]I(98pY  
return sFilePath; @01D1A  
} A7,$y!D  
) }it,<  
}vxH)U6$q  
public void setSFilePath(String value) m[Ac'la  
{ !wb~A0m  
sFilePath = value; xd BZ^Q  
} 5bznM[%xO  
d @kLLDP  
LX?r=_\  
public String getSFileName() 0*:hm%g  
{ }v$=mLy  
return sFileName; eN?P) ,  
} UE#Ni 5  
aaD$'Y,<>B  
JQh s=Xg  
public void setSFileName(String value) Jx ;"a\KD  
{ ):\{n8~  
sFileName = value; RWPd S  
} )w 8lusa  
,vdP #:  
ch8w'  
public int getNSplitter() wrb& ta  
{ (yTz^o$t|  
return nSplitter; c+i`Zd.m<  
} cxJK>%84  
I/b8  
$\@ V4  
public void setNSplitter(int nCount) ,t&-`U]AX  
{ ~md|k  
nSplitter = nCount; ^FMa8;'o  
} .rB;zA;4S)  
} ]3y5b9DuW  
&MQt2aL  
*u4X<oBS*  
/* kRXg."b(  
**Utility.java ~$ qJw?r  
*/ '>mb@m  
package NetFox; f]A6Mx6  
)?IA`7X  
)~mc1 U`b  
public class Utility { [ EID27P  
H!>oLui  
.&}4  
public Utility() 95 .'t}  
{ 3XlnI:w =  
MMr7,?,$  
hYv 6-5_  
} <J }9.k  
|QTqa~~B  
//线程睡眠 8EEQV}4  
public static void sleep(int nSecond) IS4K$Ac.  
{ W#\};P  
try{ Z#:@M[HH{  
Thread.sleep(nSecond); m'"VuH?^  
} 2CgIY89O  
catch(Exception e) 6')SJ*|yS  
{ @>nk^ l  
e.printStackTrace (); M-K@n$k   
} KdMA58)  
} 2xdJ(\JWM  
-qP[$Q  
//日志 fQ_8{=<-&X  
public static void log(String sMsg) lnSE+YJ>  
{ '*;eFnmvs:  
System.err.println(sMsg); |{IU<o x  
} u2O^3r G-  
`b`52b\6S  
c%/&@vs7  
public static void log(int sMsg) UVmyOC[Y{  
{ d?y\~<  
System.err.println(sMsg); d#:J\2V"R  
} SWO!E  
} 2|>wY%  
yx;R#8;b.  
UkbQ'P+oS  
/* R/cq00g  
**TestMethod.java Jd2Y)  
*/ 'yRv~BA  
package NetFox; mf_'| WDs  
m9w ; a  
I%C:d#p  
public class TestMethod { I"<. h'  
]sP9!hup  
[#6Esy8|  
public TestMethod() F8;4Oj  
{ ///xx/weblogic60b2_win.exe s^R2jueR  
try{ E^W*'D  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >P"/ nS"nn  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x2c*k$<p  
SiteFileFetch fileFetch = new SiteFileFetch(bean); A?k,}~  
fileFetch.start(); JU1; /3(  
} #&c;RPac!6  
catch(Exception e){e.printStackTrace ();} HFWm}vA:  
&:f'{>3z  
#(J}xz;  
} 7{F9b0zwk  
7#. PMyK9  
kGiw?~t=%  
public static void main(String[] args)  !Ocg  
{ tU/NwA"  
new TestMethod(); a(T4WDl^  
} <G?85*Nv_  
} 6-}e-H  
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