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http断点续传简单实现(java)

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/* A{)pzV25  
**SiteFileFetch.java UNv!G/i-5  
*/ dOaCdnd~  
package NetFox; Z'5&N5hx  
import java.io.*; _e8v12s  
import java.net.*; p NQ7uy  
?0sTx6x@  
!RwhVaSh  
public class SiteFileFetch extends Thread { ?5};ONjN  
aEa+?6;D  
/f oI.S  
SiteInfoBean siteInfoBean = null; //文件信息Bean e~'z;% O~  
long[] nStartPos; //开始位置 hG<[F@d  
long[] nEndPos; //结束位置 rhaq!s38:  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Lq.2vfA>  
long nFileLength; //文件长度 z9 #-  
boolean bFirst = true; //是否第一次取文件 !v%>W< 3Q  
boolean bStop = false; //停止标志 O/(vimx.#F  
File tmpFile; //文件下载的临时信息 !:esdJH  
DataOutputStream output; //输出到文件的输出流 \3K7)o^  
",Mrdxn7  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) QKVOc,Fp7i  
public SiteFileFetch(SiteInfoBean bean) throws IOException #bG6+"g{=L  
{ .YB/7-%M[  
siteInfoBean = bean; L>7@!/ 9L  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); k*,+ag*j  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); # SJJ@SM  
if(tmpFile.exists ()) lMg#zT!?  
{ *6=9 8C4I  
bFirst = false; ^k^?>h  
read_nPos(); KC(z TY  
} 'q}f3u>  
else {;u+?uY  
{ H=Cj/jE  
nStartPos = new long[bean.getNSplitter()]; y[AB,Dd  
nEndPos = new long[bean.getNSplitter()]; 9CN'2 9c  
} =h ~n5wQG  
suLC7x`Z  
JqYa~6 C  
Nx*1m BC  
} W*(- * \1[  
O kT@ _U  
DYgB_Iak  
public void run() W|n$H`;R  
{ ;<b7kepR  
//获得文件长度 )4:]gx#cr  
//分割文件 ^f"|<r  
//实例FileSplitterFetch ,D<U PtPQ  
//启动FileSplitterFetch线程 GM)q\Hx{  
//等待子线程返回 w2('75$J  
try{ 3qH1\  
if(bFirst) E GZiWBr  
{ A+4Kj~`!  
nFileLength = getFileSize(); #&L7FBJ"*v  
if(nFileLength == -1) vW?/:  
{ (mI590`f  
System.err.println("File Length is not known!"); !su773vo  
} ?q2Yk/P  
else if(nFileLength == -2) R2 J A(Hn  
{ uf (_<~  
System.err.println("File is not access!"); ),j6tq[  
} hy$VG%b;#  
else %,ScGQE  
{ g4+Hq *  
for(int i=0;i<nStartPos.length;i++) E_Y!in 70  
{ u5KAwMw%Q  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); %Lh+W<;  
} +|5 O b  
for(int i=0;i<nEndPos.length-1;i++) ZZCm438  
{ '#,C5*`  
nEndPos = nStartPos[i+1]; ;<GxonIV  
} h9iQn<lp4.  
nEndPos[nEndPos.length-1] = nFileLength; m@w469&<(q  
} FS!)KxC/-  
} CY[3%7 fv  
fH:S_7i  
T,vh=UF%]  
//启动子线程 j?k|-0  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; du#f_|xG  
for(int i=0;i<nStartPos.length;i++) VhAJ1[k4!  
{ aD_7^8>  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ucU7 @j  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @v&s|X '  
nStartPos,nEndPos,i); X-TGrdoX  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w1VYU>  
fileSplitterFetch.start(); Cx.##n0  
} "Ehh9 m1&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >+Iph2]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \+l_H4\`K  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bQwG"N  
nEndPos = " + nFileLength); (~E-=+R[$&  
// fileSplitterFetch[nPos.length-1].start(); Y5;afU='  
P4eH:0=#  
#Er"i  
//等待子线程结束 x#zj0vI-8  
//int count = 0; niW"o-}  
//是否结束while循环 u^CL }t*  
boolean breakWhile = false; o90g;Vog  
UX<-jY#'V  
k*\)z\f  
while(!bStop) iXL^[/}&?M  
{ d%epM5  
write_nPos(); BGwD{6`U  
Utility.sleep(500); hlze]d?z  
breakWhile = true; hiA\~}sl n  
iF837ng5  
u U>L (  
for(int i=0;i<nStartPos.length;i++) w%\{4T~  
{ dGkw%3[  
if(!fileSplitterFetch.bDownOver) $?]`2*i  
{ [{)Z^  
breakWhile = false; Rt&5s)O'  
break; ?_A[E]/H  
} v>Kh5H5e~  
} @o^$/AE?  
if(breakWhile) BnGoB`n  
break; vD?D]8.F~Q  
!J X7y%J  
#)twk `!^  
//count++; H-v[ShE  
//if(count>4) : D-D+x  
// siteStop(); ?CC.xE  
} G e]NA]<  
^,AE;Z T7  
S<cz2FlV  
System.err.println("文件下载结束!"); q9j~|GE|  
} bu_@A^ys  
catch(Exception e){e.printStackTrace ();} e!gNd>b {  
} Haekr*1%  
\/;c^!(<  
C/qKa[mg  
//获得文件长度 |)Dm.)/0)  
public long getFileSize() /Wjc\n$'  
{ KB :JVK^<  
int nFileLength = -1; h-;> v.  
try{ GIcq|Pe  
URL url = new URL(siteInfoBean.getSSiteURL()); pV  u[  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I *sT*;U  
httpConnection.setRequestProperty("User-Agent","NetFox"); Us'JMZ~  
CrL9|78  
Zy;jp*Q  
int responseCode=httpConnection.getResponseCode(); N0kCdJv  
if(responseCode>=400) FK~wr;[  
{ 3'`&D/n  
processErrorCode(responseCode); z _\L@b  
return -2; //-2 represent access is error 9"+MZ$  
} i7r)9^y  
 aY(s &  
hp(MKfhH  
String sHeader; Y,Z$U| U  
5YNAb/! !F  
GQY" +xa8]  
for(int i=1;;i++) Oy=0Hsh@x  
{ #<9'{i3  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S|k@D2k=  
//Utility.log(in.readLine()); mhhc}dS(H  
sHeader=httpConnection.getHeaderFieldKey(i); { >[ ]iX  
if(sHeader!=null) Ua 6O~,\  
{ P[q>;Fx*  
if(sHeader.equals("Content-Length")) H+Bon=$cE!  
{ Ji9o0YR  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @#t<!-8d  
break; sfw* _}y  
} IO"P /Q  
} OhCdBO  
else Ew PJ|Z^  
break; @Q2E1Uu%  
} oYf+I  
} f['lY1#V1  
catch(IOException e){e.printStackTrace ();} ?#:']q  
catch(Exception e){e.printStackTrace ();} Ezew@*(  
rCA!b"C2  
Tb?XKO,  
Utility.log(nFileLength); 8gE p5  
27c0wzq  
O4oN)  
return nFileLength; ">1wPq&  
} %gFIu.c  
tg#jjXV\0p  
:KX*j$5U  
//保存下载信息(文件指针位置) Ji!i}UjD7!  
private void write_nPos() (EWGX |QA  
{ 86-Rm  
try{ NwYQ6VEA  
output = new DataOutputStream(new FileOutputStream(tmpFile)); w2'z~\dG8  
output.writeInt(nStartPos.length); W[)HFh(#  
for(int i=0;i<nStartPos.length;i++) ,#, K_oz  
{ M=;csazN  
// output.writeLong(nPos); F3!@|/<w  
output.writeLong(fileSplitterFetch.nStartPos); t6KKfb  
output.writeLong(fileSplitterFetch.nEndPos); (9aOET>GG  
} ]6`K  
output.close(); MDIPoS3BRa  
} CStNCBZ|\  
catch(IOException e){e.printStackTrace ();} Y iuV\al  
catch(Exception e){e.printStackTrace ();} |-\anby<  
} Y)]VlV!`  
Hn)? xw]x  
8h|}Q_  
//读取保存的下载信息(文件指针位置) `{Oqb  
private void read_nPos() wj}LVyV  
{ ^C^I  
try{ ]JGq{I>%+6  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;7qzQ{Km  
int nCount = input.readInt(); l 7dm@S  
nStartPos = new long[nCount]; B:v_5e\f@  
nEndPos = new long[nCount]; ~YW;'  
for(int i=0;i<nStartPos.length;i++) u?SwGXi~8  
{ ceks~[rP  
nStartPos = input.readLong(); xu-bn  
nEndPos = input.readLong(); dgX%NKv1  
} m2(}$z3e  
input.close(); P6>C+T1  
} -b?M5P*:  
catch(IOException e){e.printStackTrace ();} @YaI5>,/  
catch(Exception e){e.printStackTrace ();} x@oxIXN  
} Jg'#IM  
OMjPC_  
KV;q}EyG  
private void processErrorCode(int nErrorCode) ip'{@1L  
{ Y}.f&rLe  
System.err.println("Error Code : " + nErrorCode); >+i+_^]  
}  Lhg  
F)eP55C6  
J7{D6@yLS  
//停止文件下载 CL5^>. }  
public void siteStop() `:r-&QdU o  
{ GGHeC/4  
bStop = true; o(54 A['  
for(int i=0;i<nStartPos.length;i++) .HY,'oC.  
fileSplitterFetch.splitterStop(); %|JL=E}%|  
J#@+1 Nt  
u"hr4+/  
} a|t{1]^w`  
} OC,yLQ  
//负责部分文件的抓取 xgNV0;g,  
**FileSplitterFetch.java sEw ?349Bz  
*/ uInI{>  
package NetFox; h'G  
PK&&Vu2M  
CcV@YST?  
import java.io.*; qycf;Kl:6  
import java.net.*; +Gy9K  
?@MY+r_G  
P $ h) Y  
public class FileSplitterFetch extends Thread { HtE^7i*_  
8?<J,zu@AV  
JCZ&TK  
String sURL; //File URL @*6_Rp"@  
long nStartPos; //File Snippet Start Position }>,%El/  
long nEndPos; //File Snippet End Position gV:0&g\v  
int nThreadID; //Thread's ID (C`nBiL<  
boolean bDownOver = false; //Downing is over 3ErV" R4"$  
boolean bStop = false; //Stop identical d=vD Pf  
FileAccessI fileAccessI = null; //File Access interface Z5wQhhH  
?0z/i^I  
zh?B-"O=5  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2.{<C.BK{  
{ $j(4FyH\  
this.sURL = sURL; l_2l/ff9  
this.nStartPos = nStart; i8EKzW  
this.nEndPos = nEnd; p ~+sk1[.  
nThreadID = id; ojj T  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $'#}f?  
} R*ex!u60M  
e cvZwL  
-biw{  
public void run() d|UH AX  
{ *z~J ]  
while(nStartPos < nEndPos && !bStop) oOXJ7 |n  
{ oc-o>H  
%>O}bdSf  
5*B'e{C  
try{ NLgeBLB  
URL url = new URL(sURL); @k:@mzB7R  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K_N`My  
httpConnection.setRequestProperty("User-Agent","NetFox"); $x+ P)5)  
String sProperty = "bytes="+nStartPos+"-"; 9(KffnE^  
httpConnection.setRequestProperty("RANGE",sProperty); F*:H&,  
Utility.log(sProperty); 4dSAGLpp  
e6T?2`5P  
98{n6$\  
InputStream input = httpConnection.getInputStream(); h{)`W ]~  
//logResponseHead(httpConnection); 6p,}?6^  
k5)IBO  
OXoEA a  
byte[] b = new byte[1024]; `soQp2h-  
int nRead; *9r 32]i;  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z3Xgi~c  
{ `E>o:tff  
nStartPos += fileAccessI.write(b,0,nRead); xkaed  
//if(nThreadID == 1) % <%r  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "MOmJYH  
} <(~geN  
=D 5!Xq'|  
MB.LHIo  
Utility.log("Thread " + nThreadID + " is over!"); Zl2doXC  
bDownOver = true; x1#6~283  
//nPos = fileAccessI.write (b,0,nRead); &v r0{]V^  
} X=JAyxY  
catch(Exception e){e.printStackTrace ();} ^DR`!.ttr  
} LkXF~  
} O<0-`=W,a  
) .H nK  
M""X_~&I"  
//打印回应的头信息 w6k^|."  
public void logResponseHead(HttpURLConnection con) ]G=^7O]`C!  
{ Jz_`dLL^ w  
for(int i=1;;i++) !=+hU/e  
{ G9> 0w)r  
String header=con.getHeaderFieldKey(i); 9kU|?JE  
if(header!=null) :Us NiR=l  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \,b_8^  
Utility.log(header+" : "+con.getHeaderField(header)); *wz62p  
else /vFdhh  
break; 9t0NO-a  
} &eX^ll  
} cU=EXyP%  
/57)y_ \  
Y<`uq'V  
public void splitterStop() 7ZpU -':  
{  Hh<}~s  
bStop = true; pS)/yMlVj  
} ;KW}F|  
sMqAuhw$.  
l,M?   
} ;z^C\=om  
Tk0Senq,  
1x4{~g\  
/* t{ScK%S6  
**FileAccess.java W-@}q}A  
*//文件访问(定位,写) Z&0*\.6S~  
package NetFox; /*{s1Zcb  
import java.io.*; Ea[K$NC)#  
OX)[?1m8  
c4n]#((%a  
public class FileAccessI implements Serializable{ N[AX]gOJ  
Q+'QJ7fw'|  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L+y90 T6?  
RandomAccessFile oSavedFile; &7t3D?K'qX  
long nPos; 72>/@  
|cCrLa2*-  
G4eY}3F7,4  
public FileAccessI() throws IOException pElAY3  
{ 3]1uDgfr  
this("",0); 7nAB^~)6l  
} n[pW^&7x  
StJ&YYdD  
p$ %D  
public FileAccessI(String sName,long nPos) throws IOException fPW(hb;  
{ fB3W} dr  
oSavedFile = new RandomAccessFile(sName,"rw"); 1zUo.Tg0  
this.nPos = nPos; D|p`~(  
oSavedFile.seek(nPos); P Yp<eo\  
} [vs5e3B)  
'XHKhpm<  
ki[Yu+';}  
public synchronized int write(byte[] b,int nStart,int nLen) WS?"OTH.^\  
{ h{&}p-X&[  
int n = -1; 3-5X^!C  
try{ Eh&et0&=g  
oSavedFile.write(b,nStart,nLen); ?|t9@r  
n = nLen; q'%-8t  
} G 'sEbw'[  
catch(IOException e) gE>_:s   
{ #PpmR _IX  
e.printStackTrace (); Z;6v`;[  
} ?UlAwxn  
MwN.Ll  
*uq;O*s  
return n; 451TTqc  
}  1 U|IN=  
kCO`JAH#  
u"*@k^}(  
} }&Gt&Hm>K  
n9}3>~ll  
 *TEgV  
/* _{fh/{b1  
**SiteInfoBean.java U=4tJb  
*/ 8%qHy1  
package NetFox; ]\y:AkxhJ  
^x8yW brE  
9 -\.|5;:  
public class SiteInfoBean { lC8DhRd0_  
38 Q>x  
mlsM;A d2  
private String sSiteURL; //Site's URL Gy+/P6  
private String sFilePath; //Saved File's Path Lb2bzZbhx  
private String sFileName; //Saved File's Name #Ont1>T,G  
private int nSplitter; //Count of Splited Downloading File WQ(*A $  
<g SZt\  
|#p`mc%f~\  
public SiteInfoBean() 8cV3VapF  
{//nSplitter的缺省值为5 o& g0 1t  
//default value of nSplitter is 5 sOegR5?;  
this("","","",5); G1t{a:  
} 95 7Cr  
+9MoKn=h  
FwB }@)3  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z@Klj qN  
{ tnv @`xBn  
sSiteURL= sURL; JVPl\I  
sFilePath = sPath; ?pS,?>J f  
sFileName = sName; ZK1H%&P=R  
this.nSplitter = nSpiltter; _O76Aw-@l  
;<j[0~qp:  
+K6j p  
} 'jr\F2  
v{/z`J!JR  
`1AVw] k  
public String getSSiteURL() ;7jszs.6%  
{ #GTR}|Aga  
return sSiteURL; :qfP>Ok  
} FaNr}$Pe  
-@6R`m= >  
T*AXS|=ju  
public void setSSiteURL(String value) &:K!$W  
{ #le1 ^ <w7  
sSiteURL = value; E}7@?o7u}  
} I?2S{]!?  
U3R;'80 f  
/$w,8pV =  
public String getSFilePath() g4Y1*`}2f  
{ P2U^%_~  
return sFilePath; WOw( -  
} (gdi 2  
zEHX:-f8  
(KHO'QNMt^  
public void setSFilePath(String value) +v!% z(  
{ reBAxmt   
sFilePath = value; UDBMf2F]  
} }:04bIaV  
16J" QUuG  
E79'<;K,zs  
public String getSFileName() (qG}`?219J  
{ $,@PY5r  
return sFileName; })?t:zX#*  
} `#/0q*$  
?@*hU2MTC  
0bl?dOV{  
public void setSFileName(String value) %< ^IAMkp  
{ uWtj?Q+M|  
sFileName = value; 4l2/eh]Hc(  
} hDn?R}^l{  
5_H`6-q  
zwLJ|>  
public int getNSplitter() >8v4fk IK  
{ {*BZ;Xh\8  
return nSplitter; Em<B 9S  
} Whd\Ub8(  
JZ l"k  
#YiphR&  
public void setNSplitter(int nCount) j[ fE^&  
{ w \U?64  
nSplitter = nCount; *F^t)K2  
} ^\(<s  
} HQy:,_f@  
prk@uYCa =  
!l(O$T9 T  
/* qh]D=i  
**Utility.java 6zZT5 Kn  
*/ 6T9?C|q  
package NetFox; I2&R+~ktR  
(:9=M5d  
,pTj'I  
public class Utility { B - 1Kfc  
CVAX?c{   
A)5;ae  
public Utility() w$evAPuz^  
{ u6t%*''  
S^q%+Z  
Ux!q(9<_  
} YXlaE=9bn  
 d5YL=o  
//线程睡眠 JeXA*U#  
public static void sleep(int nSecond) l:.q1UV  
{ kM;}$*?  
try{ riu_^!"Z_  
Thread.sleep(nSecond); oG$OZTc  
} cHAq[Ebp2!  
catch(Exception e) o'KBe%@/  
{ MwHxn%  
e.printStackTrace (); J5zKwt  
}  oB8LJZ;  
} Q>yO,H|  
}v`Z. ?|Z  
//日志 sLOkLz"x  
public static void log(String sMsg) Maw$^Tz,  
{ <ht^Ck  
System.err.println(sMsg); qCI0[U@  
} [!S%nYs&8L  
fAT+x1J\  
5M? I-m  
public static void log(int sMsg) [NU@A>H  
{ <Em|0hth  
System.err.println(sMsg); S^:7V[=EgI  
} (,j ~s{  
} \ ^3cNw  
1 uJpn  
7.nNz&UG]5  
/* 5`FPv4   
**TestMethod.java R/\qDY,@  
*/ qM(@wFg  
package NetFox; 8FJPw"9  
wl0i3)e:  
ZRP[N)Ld$  
public class TestMethod { n%d7`?tm4  
`G<|5pe  
4CK$W` V  
public TestMethod() &9 khIJI n  
{ ///xx/weblogic60b2_win.exe 'R nvQ""  
try{  +wE>h>?;  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z!z#+G  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IQyw>_~]  
SiteFileFetch fileFetch = new SiteFileFetch(bean); |5(un/-C  
fileFetch.start(); 4<S=KFT_  
} p&lT! 5P!A  
catch(Exception e){e.printStackTrace ();} Tilw.z  
3z!^UA>q  
>8EmfjUoc  
} '=(@3ggA:  
[W8?ww%qT  
_YA;Nd#%k  
public static void main(String[] args)  Eikt,  
{ #OsUF,NU  
new TestMethod(); hOr4C4  
} iz:O]kI  
} 4=ZN4=(_[  
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