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http断点续传简单实现(java)

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/* IO9|o!&>  
**SiteFileFetch.java QD{1?aY  
*/ 1goRO  
package NetFox; H[nBNz)C  
import java.io.*; l,]%D  
import java.net.*; ?Y -;781  
T30fp  
s@"|o3BX  
public class SiteFileFetch extends Thread { =bja\r{  
svDnw cl  
"OYD9Q''  
SiteInfoBean siteInfoBean = null; //文件信息Bean |>xuH#Q  
long[] nStartPos; //开始位置 ~+0IFJ`}  
long[] nEndPos; //结束位置 <z2.A/L  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 6'N_bNW  
long nFileLength; //文件长度  QtG6v<A  
boolean bFirst = true; //是否第一次取文件 ps:`rVQ7  
boolean bStop = false; //停止标志 13Z,;YW  
File tmpFile; //文件下载的临时信息 _*?qOmf=  
DataOutputStream output; //输出到文件的输出流 O9d"Z$~n=j  
#k)z5vZ$h  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) hp/pm6  
public SiteFileFetch(SiteInfoBean bean) throws IOException pO7OP"q1  
{ v X6JjE!  
siteInfoBean = bean; CUG"2K9  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); \+sa[jK  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); b\H&E{Gn|x  
if(tmpFile.exists ()) (M1YOK)I  
{ M_UmnqN1C  
bFirst = false; "5k 6FV  
read_nPos(); *A8*FX>\F  
} \WTKw x  
else 6@/k|t>OT  
{ (!5Pl`:j"  
nStartPos = new long[bean.getNSplitter()]; \/j,  
nEndPos = new long[bean.getNSplitter()]; s+fxv(,"c  
} R!"|~OO  
,9jk<)m]L  
"u4x#7n|  
`5h^!="  
} HH7WMYoKY  
\db=]L=|  
CC"a2Hu/  
public void run() @w.DN)GPo  
{ L>1y[ Q  
//获得文件长度 56c[$ q  
//分割文件 5vR])T/S0  
//实例FileSplitterFetch z&9MkbH1  
//启动FileSplitterFetch线程 w.J$(o(/  
//等待子线程返回 gy,)% {,G  
try{ 'Z.C&6_  
if(bFirst) Zqe$S +u  
{ ?yj g\S?L  
nFileLength = getFileSize(); !LpjTMYs  
if(nFileLength == -1) H.>EO&#|p  
{ vxk0@k_  
System.err.println("File Length is not known!"); # }}6JM  
} r^msJ|k8[  
else if(nFileLength == -2) >0ZG&W9  
{ @|t]9  
System.err.println("File is not access!"); w0j'>4  
} sUc[!S:/  
else R\7r!38  
{ ^{=UKf{  
for(int i=0;i<nStartPos.length;i++) V[*>}XQER  
{ 9Xa.%vw>  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); . 70=xH  
} '&,p>aM  
for(int i=0;i<nEndPos.length-1;i++) ,:J[|9  
{ #&r}J  
nEndPos = nStartPos[i+1]; V3cKdlu Na  
} DBaZcO(U  
nEndPos[nEndPos.length-1] = nFileLength; y>E:]#F  
} @73kry v  
} hO3 q|SL  
$)KODI>|  
YRBJ(v"9  
//启动子线程 iZ}c[hC'3`  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }0anssC  
for(int i=0;i<nStartPos.length;i++) t}Td$K7  
{ z?Z"*z  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d(^HO~p  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6A.%)whI;  
nStartPos,nEndPos,i); %vZHHBylu  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \*{MgwF  
fileSplitterFetch.start(); Ths~8{dMb  
} BGj!/E  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T _UJ?W  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pi#a!Quf\  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u0=&_Q(=  
nEndPos = " + nFileLength); R6Md_t\  
// fileSplitterFetch[nPos.length-1].start(); Vrlqje_Q  
tw zV-8\  
RR+kjK?  
//等待子线程结束 P/WGB~NH  
//int count = 0; @uV]7d"z(  
//是否结束while循环 M1NdlAAf  
boolean breakWhile = false; 6[R6P:v&'G  
4<PupJ  
pRE^; 4}z  
while(!bStop) rloxM~7!,)  
{ j<BRaT  
write_nPos(); GLZ*5kw  
Utility.sleep(500); NhNd+SCZ@  
breakWhile = true; y!x[N!a  
M"p%CbcI]  
C_q2bI  
for(int i=0;i<nStartPos.length;i++) oO3 ^9?Z  
{ svxjad@l/  
if(!fileSplitterFetch.bDownOver) V*2 * 5hx  
{ {4/*2IRN9h  
breakWhile = false; ?#&[1.= u  
break; (vD==n9Hd  
} \P":V  
} `\"<%CCe  
if(breakWhile) *}#HBZe(9  
break; [!3cWJCt  
)jUPMIo  
[ypE[   
//count++; *$R9'Yo}F  
//if(count>4) -^`s#0( y^  
// siteStop(); _](y<O^9yO  
} b5]<!~Fv:`  
T;{}bc&I  
L.-qTh^P  
System.err.println("文件下载结束!"); AsuugcN*  
} z(.,BB[  
catch(Exception e){e.printStackTrace ();} ^["D>@yIR  
} s.;'-oA  
r|uR!=*|?  
N>a~k}pPH  
//获得文件长度 ^q& Rl\  
public long getFileSize() 7CF>cpw  
{ ^pew'p HQ  
int nFileLength = -1; ^:ny  
try{ `~lG5|  
URL url = new URL(siteInfoBean.getSSiteURL()); ]:2Ro:4Yv  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); . bUmT!  
httpConnection.setRequestProperty("User-Agent","NetFox"); ~fL`aU&  
z!b:|*m]w  
%1#|>^  
int responseCode=httpConnection.getResponseCode(); dZ* &3.#D5  
if(responseCode>=400) Y$Rte .?  
{ m*iSW]&  
processErrorCode(responseCode); NPO!J^^  
return -2; //-2 represent access is error EFI!b60mc  
} gG.+3=  
p-(V2SP/)t  
%qeNC\6N  
String sHeader; o2$A2L9P  
OKau3T]  
d^tY?*n  
for(int i=1;;i++) ' i5}`\  
{ bcu Uej:  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VFnxj52<  
//Utility.log(in.readLine()); C{t}q*fG 5  
sHeader=httpConnection.getHeaderFieldKey(i); @44*<!da  
if(sHeader!=null) !h}Vz  
{ aA>!p{/x  
if(sHeader.equals("Content-Length")) y,jpd#Y  
{ ir\)Hz2P  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !U2<\!_  
break; HL$7Ou  
} `\ IaeMvo  
} `<T4 En  
else Vx5fQ mx  
break; dikX_ Q>D  
} "mU2^4q  
} XJl 3\*  
catch(IOException e){e.printStackTrace ();} RHvK Wt  
catch(Exception e){e.printStackTrace ();} #7:ah  
ER&\2,fZ  
Ji=`XsV  
Utility.log(nFileLength); mrKIiaU<J  
${ DSH  
mrG#ox4$  
return nFileLength; ]0(ZlpT  
} N^F5J  
m@D :t 5  
kDRxu!/  
//保存下载信息(文件指针位置) @_c&lToj_  
private void write_nPos() g.;2N9  
{ &F[N$6:v  
try{ N(J#<;!yb  
output = new DataOutputStream(new FileOutputStream(tmpFile)); wNFx1u^/)  
output.writeInt(nStartPos.length); >XuPg(Ow  
for(int i=0;i<nStartPos.length;i++) }9z$72;Qdq  
{ u9c^YCBM  
// output.writeLong(nPos); t(.vX  
output.writeLong(fileSplitterFetch.nStartPos); l`X?C~JhJ  
output.writeLong(fileSplitterFetch.nEndPos); r~,3  
} 9]G~i`QQ  
output.close(); D]'8BS3  
} vt(}8C+  
catch(IOException e){e.printStackTrace ();} XS&;8 PO  
catch(Exception e){e.printStackTrace ();} 9 MQwc  
} |KPNl\%ID  
/Gb)BJk!  
Ho&f[T(  
//读取保存的下载信息(文件指针位置) S @!z'$&  
private void read_nPos() "_BWUY  
{ !VudZ]Sg  
try{ ?wIEXKI  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s6;ZaU  
int nCount = input.readInt(); tdu:imH~  
nStartPos = new long[nCount]; A+\rGVNH'S  
nEndPos = new long[nCount]; e!C,<W&B\  
for(int i=0;i<nStartPos.length;i++) *U8,Q]gS  
{ 5yV>-XT+-  
nStartPos = input.readLong(); mQU t 'j4  
nEndPos = input.readLong(); .]<iRf[\[  
} Gcxz$.(  
input.close(); M#8_Qbvfk  
} JH2-'  
catch(IOException e){e.printStackTrace ();} Rf=-Q %  
catch(Exception e){e.printStackTrace ();} $|!3ks  
} HG5E,^1n  
Pum&\.l  
Y~#.otBL&  
private void processErrorCode(int nErrorCode) w; f LnEz_  
{ \l5G   
System.err.println("Error Code : " + nErrorCode); F 6+4Yy+  
} l[WX77bp=  
:8+x&zn  
A&-2f]L tl  
//停止文件下载 j&8G tE1b  
public void siteStop() Ck/w:i@>?  
{ 4VsttT  
bStop = true; fP( n3Q  
for(int i=0;i<nStartPos.length;i++) =gd~rk9  
fileSplitterFetch.splitterStop(); k%N$eO$  
Vm I Afe  
Z{F^qwne  
} +j8-l-o  
} :F"NF  
//负责部分文件的抓取 cvtn,Ml6  
**FileSplitterFetch.java 7s0y.i~  
*/ +&M>J|  
package NetFox; x;STt3M~  
!0KN A1w,  
=C)2DWJ1  
import java.io.*; e>uq/|.!  
import java.net.*; tjne[p  
ojIGfQV  
"%rU1/@#  
public class FileSplitterFetch extends Thread { J~ z00p`E  
69odE+-X.  
V4,\vgGu  
String sURL; //File URL n2'XWbMaL  
long nStartPos; //File Snippet Start Position bK!uR&i^l  
long nEndPos; //File Snippet End Position hb)83mH}  
int nThreadID; //Thread's ID  [cfXcl  
boolean bDownOver = false; //Downing is over ,x[~|J!  
boolean bStop = false; //Stop identical ob[G3rfd@Z  
FileAccessI fileAccessI = null; //File Access interface 5'wFZ=>vMt  
ZNDjk  
QbWeQ[V{  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u*7>0o|H:  
{ i>pUTT _[  
this.sURL = sURL; mJVru0  
this.nStartPos = nStart; ]qk`Yi  
this.nEndPos = nEnd; a5`9mR)Y$'  
nThreadID = id; p%\&M bA  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eFQz G+/  
} H]{`q  
)@ .0ai  
OeQ~g-n  
public void run() j#H&~f  
{ S09Xe_q  
while(nStartPos < nEndPos && !bStop) ]4 \6_J&  
{ %w3tzE1Hq  
7U&<{U<  
`]/0&S  
try{ q-+_Y `_\  
URL url = new URL(sURL); ]^QO ^{Sz  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VY!A]S"  
httpConnection.setRequestProperty("User-Agent","NetFox"); _Vt CC/  
String sProperty = "bytes="+nStartPos+"-"; ^/$U(4  
httpConnection.setRequestProperty("RANGE",sProperty); 2(9~G|C.  
Utility.log(sProperty); 07,&weQ  
"haJwV6-  
O<?.iF%  
InputStream input = httpConnection.getInputStream(); 7VfPS5se  
//logResponseHead(httpConnection); U\"FYTC  
v dU)  
o fCN[u  
byte[] b = new byte[1024]; pEG!j ~  
int nRead; Tx$bg(  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,@8*c0Y~<!  
{ aq^OzKP?  
nStartPos += fileAccessI.write(b,0,nRead); m9$lOk4/  
//if(nThreadID == 1) YE-}1&8  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {>X2\.Rl  
} v 5&8C  
C'joJEo  
O F?o  
Utility.log("Thread " + nThreadID + " is over!"); ^`9O$.'@  
bDownOver = true; .H86f !=  
//nPos = fileAccessI.write (b,0,nRead); A] f^9F@  
} %^;rYn3  
catch(Exception e){e.printStackTrace ();} *adwCiB  
} B(R$5Xp  
} -JdNA2P  
h,i=Y+1  
2)|G%f_lS  
//打印回应的头信息 Okd7ua-f  
public void logResponseHead(HttpURLConnection con) *Ud P1?Y  
{ ,GF(pCZzG  
for(int i=1;;i++) fvV5G,lD3h  
{ sN/8OLc  
String header=con.getHeaderFieldKey(i); CYhSCT!-?  
if(header!=null) 6{[ uCxxl  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }Q;^C  
Utility.log(header+" : "+con.getHeaderField(header));  ByjgM`  
else iz6+jHu'l  
break; vyruUYFWe  
} xGw|@d  
} GrM`\MIO  
$1|65j[e  
fRcy$  
public void splitterStop() di~ [Ivw  
{ AZbFj-^4  
bStop = true; %07vH&<C.  
} E qt\It9  
3s,a%GOk  
FOSC#W9E  
} BvpUcICJ  
 0gJ{fcI  
ua%j}%G(  
/* |k/;1.b!9(  
**FileAccess.java -^$IjK-N  
*//文件访问(定位,写) kOv37c'  
package NetFox; +)*oPSQ5  
import java.io.*; o? wEX%  
"lBYn2W  
UH7FIM7kX  
public class FileAccessI implements Serializable{ a)rT3gl  
81S0:=   
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -dH]_  
RandomAccessFile oSavedFile; V`"Cd?R0Z  
long nPos; d+IN-lR(  
0@}:`OynX  
F Xp_`9.zH  
public FileAccessI() throws IOException jlaC: (6  
{ 0$. ;EGP  
this("",0); m=D9V-P  
} BVxk}#d  
cbv%1DT3  
}?,Eb~q  
public FileAccessI(String sName,long nPos) throws IOException X GDJCN  
{ 1 o\COnt  
oSavedFile = new RandomAccessFile(sName,"rw"); s'k} .}  
this.nPos = nPos;  y7.oy"  
oSavedFile.seek(nPos); ,TQ;DxB}=E  
} g"X!&$ &  
O7zj8  
?q}:ojrs1  
public synchronized int write(byte[] b,int nStart,int nLen) NxN~"bfh  
{ Z" dU$ ,n  
int n = -1; ~{{@m]P  
try{ C9nCSbGMY{  
oSavedFile.write(b,nStart,nLen); y:R+;91  
n = nLen; =nG>aAG  
} 7Q # A  
catch(IOException e) k, jcLX.  
{ ePiZHqIsv/  
e.printStackTrace (); c^}DBvG,  
} UZ7ukn-  
23P7%\  
3u1\zse  
return n; \&^U9=uq  
} p)*x7~3e  
OT}P0 ~4s  
~Da-|FKa>  
} QT[4\)  
G$6mtw6[M  
u'Z^|IVfo  
/* 88A,ll%  
**SiteInfoBean.java >$;,1N $bd  
*/ PS`F  
package NetFox; \kC'y9k  
d(9C7GLC,  
7$Pf  
public class SiteInfoBean { -n6e;p]  
DWk2=cO  
<ua! ]~  
private String sSiteURL; //Site's URL .}iRe}=  
private String sFilePath; //Saved File's Path <l$ vnq  
private String sFileName; //Saved File's Name :hDv^D?3  
private int nSplitter; //Count of Splited Downloading File 71,GrUV:  
'L G )78sk  
;! #IRR  
public SiteInfoBean() gmtS3,  
{//nSplitter的缺省值为5 K,@} 'N  
//default value of nSplitter is 5 C@@PLsMg  
this("","","",5); D1Q]Z63,  
} ]|B_3* A  
p}|<EL}Z9  
9oj0X>| 1  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nSq$,tk(  
{ Bh()?{q  
sSiteURL= sURL; GCp90  
sFilePath = sPath; d"}lh:L9  
sFileName = sName; gyOAvx  
this.nSplitter = nSpiltter; <P-AlHYV-  
a#+;BH 1  
#[y2nK3zF  
} |5\: E}1  
8j8~?=$a6Q  
Kj#h9e  
public String getSSiteURL() <|VV8r93  
{ M#xol/)h  
return sSiteURL; UW-`k1  
} ^'4I%L"  
d@{#F"o  
]NY^0SqM  
public void setSSiteURL(String value) #QiNSS  
{ %m "9 =C  
sSiteURL = value; E4xybVo@  
} MG3xX;  
- *xn`DH  
14p{V} f3  
public String getSFilePath() Mqm9i  
{ Hh &s.ja  
return sFilePath; L^L.;1  
} $%5vJiuk  
|O[ I=!  
0t)5KO  
public void setSFilePath(String value) HVNX"`]"  
{ HUx -8<ws  
sFilePath = value; L%/atl!  
} 7h\U}!  
QX+&[G!DZH  
6' 9zpe@`  
public String getSFileName() (b+o$C  
{ }\vw>iHPX@  
return sFileName; Gvqu v\  
} %`]fZr A]#  
8!7`F.BX  
>%85S>e  
public void setSFileName(String value) U6~79Hnt  
{ (o1o);AO  
sFileName = value; D^A#C<Gs  
} X9#i!_*  
/.:&9 c  
k~qZ^9QB~  
public int getNSplitter() q (}#{OO  
{ 57:27d0y  
return nSplitter; T$tO[QR/  
} *TYOsD**9  
1#nY Z%  
h~k+!\  
public void setNSplitter(int nCount) _j|U>s   
{ HvW6=d(#  
nSplitter = nCount; '.#3h$d  
} b%e7rY2  
} l,ra24  
d 2z!i^:  
r%%<   
/* (sEZNo5n  
**Utility.java i^V3u  
*/ N0UZ%,h\  
package NetFox; IUQYoKz4}A  
~uEI}z  
Tnb5tHjnh  
public class Utility { M/jdMfU  
PAv<J<d  
1f0maN  
public Utility() %DhLU~VX  
{ tdn|mX#  
+=(@=PJ6  
iL3k8:x  
} T0K*!j}O  
MMf_  
//线程睡眠 Io<L! =>  
public static void sleep(int nSecond) 9D51@b6k  
{ ~lH2# u>g  
try{ =p#:v  
Thread.sleep(nSecond); ie<m)  
} Ve t<,;Te  
catch(Exception e) Lq{/r+tt/  
{ DO ,7vMO  
e.printStackTrace (); D~@lpcI  
} !-q)9K?  
} q8 Rep  
fnudy% oo  
//日志 S?# 'Y*h  
public static void log(String sMsg) tMr$N[@r  
{ gBo~NLrf  
System.err.println(sMsg); @ jD#Tn-*  
} pNc4o@-  
LgA> ,.  
2 m2$jp0  
public static void log(int sMsg) {)& b6}2h  
{ avxI%%|  
System.err.println(sMsg); QykHB k  
} pcPRkYT[ M  
} Is }?:ET  
0ZtH  
QHe:  
/* Y,d|b V*FH  
**TestMethod.java CpC6vA.R  
*/ I9kBe}g3  
package NetFox; a>Xq   
SW=%>XKkh  
yb'v*B ]  
public class TestMethod { RBOhV/f  
kk+:y{0V  
UymhBh  
public TestMethod() &Y$)s<u8.  
{ ///xx/weblogic60b2_win.exe ()yOK$"  
try{ <"x *ZT  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /5C>7BC  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YPS,[F'B.  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8YkCTJfBGu  
fileFetch.start(); 7kQ,D,c'  
} -|_io,eL;  
catch(Exception e){e.printStackTrace ();} Fo&ecWhw  
kud2O>>  
&A~(9IV  
} -(|}:J  
t 2&}  
73(5.'F  
public static void main(String[] args) %)j^>W5  
{ dhI+_z   
new TestMethod(); mbZ g2TTy  
} q@iZo,Yk  
} l[{Ci|4  
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