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http断点续传简单实现(java)

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/* 64xq@_+  
**SiteFileFetch.java 3 d $  
*/ 1&N|k;#QS  
package NetFox; \)Jv4U\;  
import java.io.*; &* GwA  
import java.net.*; {];4  
oz $T.  
juOOD   
public class SiteFileFetch extends Thread { 0s)B~  
i\hH .7G1  
f[v~U<\R  
SiteInfoBean siteInfoBean = null; //文件信息Bean *AX)QKQ@  
long[] nStartPos; //开始位置 yem*g1  
long[] nEndPos; //结束位置 NCbl|v=  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 )#ze  
long nFileLength; //文件长度 3S='/^l  
boolean bFirst = true; //是否第一次取文件 w}n:_e  
boolean bStop = false; //停止标志 ]yu,YZ@7  
File tmpFile; //文件下载的临时信息 L$zI_ z  
DataOutputStream output; //输出到文件的输出流 !#cZ!  
8was/^9;  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) .s$#: ls?  
public SiteFileFetch(SiteInfoBean bean) throws IOException *4}l V8  
{ k#"Pv"  
siteInfoBean = bean; Ij; =  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); V"":_`1VW  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); h $)t hW  
if(tmpFile.exists ()) w6tb vhcmU  
{ jRIjFn|~{Y  
bFirst = false; . 2_t/2  
read_nPos();  /;LteBoY  
} k 1;,eB  
else [?TQ!l}8A  
{ )US|&> o8  
nStartPos = new long[bean.getNSplitter()]; 2{naSiaq  
nEndPos = new long[bean.getNSplitter()]; G"!YV#"~  
} 'TclH80  
}G n2%  
AU1P?lk  
#6{"c r6l  
} il^SGH  
E.W7`zl  
+js3o@Ku{\  
public void run() bh=d'9B@&J  
{ .UNh\R?r  
//获得文件长度 t6 :;0[j  
//分割文件 {m5tgVi&  
//实例FileSplitterFetch W"9iFj X  
//启动FileSplitterFetch线程 g*8LdH 6mq  
//等待子线程返回 b:fy  
try{ '>FJk`iI  
if(bFirst) H8 yc<  
{ KLBV(`MS  
nFileLength = getFileSize(); -,j J{Y~  
if(nFileLength == -1) .XM3oIaW  
{ rN#ydw:9  
System.err.println("File Length is not known!"); _DfI78`(  
} A(AyLxB47*  
else if(nFileLength == -2) n0:+D R  
{ Zrfp4SlZZ  
System.err.println("File is not access!"); U|odm58s  
} m'1NZV%#  
else Cnf;5/  
{ 2D-ogSIo  
for(int i=0;i<nStartPos.length;i++) qg#WDx /  
{ Bv"Fx* {W  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); WH :+HNl1d  
} L;.6j*E*  
for(int i=0;i<nEndPos.length-1;i++) X70vDoW  
{ j9C=m"O  
nEndPos = nStartPos[i+1]; 5n;|K]UW  
} Avw"[~Xd  
nEndPos[nEndPos.length-1] = nFileLength; 9[5NnRv$P  
} 2YK4 SL  
} &B3Eq 1A  
{y0*cC  
:K{`0U&l5  
//启动子线程 tF)K$!GR[  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bTC2Ya  
for(int i=0;i<nStartPos.length;i++) IBl}.o&]B#  
{ q|2{W.P5qi  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), THQ W8 V  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FM9b0qE  
nStartPos,nEndPos,i); M0o=bYI  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G1B~?i2$ ?  
fileSplitterFetch.start(); pfg"6P  
} _J&u{  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rPK?p J  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GN{\ccej  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )<4o"R:*  
nEndPos = " + nFileLength); W"Dj+/uS  
// fileSplitterFetch[nPos.length-1].start(); t&SJ!>7_c  
d%9I*Qo0,  
sAk~`(:4!  
//等待子线程结束 '.~vN L+ O  
//int count = 0; @FkNT~OZ  
//是否结束while循环 &dvJg  
boolean breakWhile = false; 5WP[-J)  
aGp <%d  
.&7=ZY>E  
while(!bStop) 4q@o4C<0  
{ 3]'=s>UO>^  
write_nPos(); n i@D7:h  
Utility.sleep(500); v)N6ZOj*C  
breakWhile = true; i#lvt#2J0  
w;H  
wO} 3i6  
for(int i=0;i<nStartPos.length;i++) c%pW'UE&  
{ C Cq<y  
if(!fileSplitterFetch.bDownOver) K1O/>dN_\O  
{ 9YHSL[  
breakWhile = false; < Q\`2{  
break; _1y|#o  
} 2EE/xnwX  
} F)e*w:D  
if(breakWhile) "+nURdicO  
break; l=9 &  
!dhZs?/UI  
9 K$F.{cx  
//count++; *-+~H1tP  
//if(count>4) pzU">)  
// siteStop(); .j88=t0  
} 9ciL<'H\  
TOMvJ>bF  
g/z9bOgIX  
System.err.println("文件下载结束!"); 8f^URN<x  
} C==tJog[  
catch(Exception e){e.printStackTrace ();} yF0,}  
} Z+t?ah00  
c'`7p/l.  
| nry^zb  
//获得文件长度 n4."}DO  
public long getFileSize() l$m^{6IYc  
{ Bo%M-Gmu  
int nFileLength = -1; BqZLqGO Ku  
try{ 3=bzIU  
URL url = new URL(siteInfoBean.getSSiteURL()); ' 1P_*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I4|p;\`fK  
httpConnection.setRequestProperty("User-Agent","NetFox"); cIM5;"gLP  
vp mSzh  
.v1rrH?  
int responseCode=httpConnection.getResponseCode(); h:bs/q+-  
if(responseCode>=400) WtRy~5A2  
{ $<s@S;Ri  
processErrorCode(responseCode); 5jNBt>.0  
return -2; //-2 represent access is error t 1C{  
} 1b|<   
#s yP=  
,7%(Jj$ ^  
String sHeader; ;o^m"I\y  
G#@<bg3  
;k/0N~  
for(int i=1;;i++) P\zi:]h[Gh  
{ 7KM!\"PM  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _IlL'c5  
//Utility.log(in.readLine()); (OG@]|-  
sHeader=httpConnection.getHeaderFieldKey(i); /-|xxy  
if(sHeader!=null) $ @1&G~x  
{ `SW`d<+L  
if(sHeader.equals("Content-Length")) eHnC^W}|s  
{ 82/iVm1  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K=(&iq!VO  
break; q6_1`Ew  
} #UWQ (+F  
} 6@F Z,e  
else 3"L$*toRA  
break; Be]o2N;J  
} GtGToI  
} :cC`wX$  
catch(IOException e){e.printStackTrace ();} R:ar85F  
catch(Exception e){e.printStackTrace ();} 7H >dv'  
R2J3R5 S=[  
0]HK (,/h  
Utility.log(nFileLength); n,HWVo>([  
,MvvW{EY  
&H+<uYV  
return nFileLength; g:,4Kd|  
} @~N#)L^  
"t\9@nzdX  
IS=)J( 0  
//保存下载信息(文件指针位置) QM_~w \  
private void write_nPos() q?0goL  
{ aPb!-o{  
try{ iTK1I0  
output = new DataOutputStream(new FileOutputStream(tmpFile)); QiRzA4-zq  
output.writeInt(nStartPos.length); 9QX{b+}"e  
for(int i=0;i<nStartPos.length;i++) D 3HB`{  
{ Ys3C'Gc  
// output.writeLong(nPos); G: &Q)_  
output.writeLong(fileSplitterFetch.nStartPos); l{pF^?K  
output.writeLong(fileSplitterFetch.nEndPos); Z$hxo )|  
} U)l>#gf8  
output.close();  /KV@Ce\  
} dkn_`j\v  
catch(IOException e){e.printStackTrace ();} B"B  
catch(Exception e){e.printStackTrace ();} oNh .Zgg  
} R1m18GHQ  
,}|V'y  
?<}qx`+%Q  
//读取保存的下载信息(文件指针位置) .ZJh-cd  
private void read_nPos() e| l?NXRX  
{ 2'}2r ~6  
try{ hs*:!&E  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {Y/  
int nCount = input.readInt(); 02+^rqIx5  
nStartPos = new long[nCount]; r-0 7!A  
nEndPos = new long[nCount]; 1%:A9%O)t  
for(int i=0;i<nStartPos.length;i++) Ud9\;Qse  
{ ]E3g8?L  
nStartPos = input.readLong(); ;kFp)*i  
nEndPos = input.readLong(); 23fAc"@ B  
} 9"aTF,'F/  
input.close(); EXi+pm  
} q_K1L  
catch(IOException e){e.printStackTrace ();} 2>r.[  
catch(Exception e){e.printStackTrace ();} @6Mo_4)O  
} [&4y@  
tw(2V$J  
%B?5l^W@  
private void processErrorCode(int nErrorCode) z>&D~0  
{ V,"'k<y  
System.err.println("Error Code : " + nErrorCode); GkO6r'MVE  
} L7b{H2 2  
@Uu\x~3y  
y7Ub~q U  
//停止文件下载 ZN1p>+oY!  
public void siteStop() NR [VGZj  
{ hPH7(f|c{g  
bStop = true; GJ$,@  
for(int i=0;i<nStartPos.length;i++) g-s@m}[T  
fileSplitterFetch.splitterStop(); V:+bq`  
0CR;t`M@  
hh{liS% 10  
} d"cfSH;h  
}  (M=Br  
//负责部分文件的抓取 uXC?fMWp.  
**FileSplitterFetch.java JQCwI`%i  
*/ !K2[S J  
package NetFox; RAxz+1JT  
&sWyh[`P  
PLyu1{1" z  
import java.io.*; _aGdC8%[  
import java.net.*; WI9.?(5q  
7lpVK]  
u rOGOa$  
public class FileSplitterFetch extends Thread { .G]# _U  
a]k&$  
{3R ax5Ty  
String sURL; //File URL ^/uGcz|.  
long nStartPos; //File Snippet Start Position Rb0{t[IU  
long nEndPos; //File Snippet End Position tvUvd(8 w  
int nThreadID; //Thread's ID  R pbl)  
boolean bDownOver = false; //Downing is over oGqv,[$qN  
boolean bStop = false; //Stop identical ?x0yiV~dL  
FileAccessI fileAccessI = null; //File Access interface 2uTa}{/%  
QUDVsN#  
Ss:,#|   
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +g[B &A!d+  
{ K_aN7?#.v`  
this.sURL = sURL; ._3NqE;  
this.nStartPos = nStart; .R'i=D`Pz  
this.nEndPos = nEnd; i=D,T[|>a  
nThreadID = id; ^&.?kJM  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -T8 gV1*(<  
} 1sJN^BvuG  
lN'/Z&62  
""d>f4,S  
public void run() a3 x~B=E  
{ e2fct|'  
while(nStartPos < nEndPos && !bStop) X A|`wAGP  
{ z,)sS<t(  
&^H "T6  
h~@+M5r,  
try{ [ lW "M  
URL url = new URL(sURL); \_E.%K  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fz3*oJ'  
httpConnection.setRequestProperty("User-Agent","NetFox"); /WfVG\NF  
String sProperty = "bytes="+nStartPos+"-"; g@k9w{_  
httpConnection.setRequestProperty("RANGE",sProperty); av?BpN"l  
Utility.log(sProperty); S+G)&<a^  
VZoOdR:d  
}v,THj  
InputStream input = httpConnection.getInputStream(); bEKLameKv  
//logResponseHead(httpConnection); DO1{r/Ib.{  
Oy&'zigJ  
q#`^EqtUF  
byte[] b = new byte[1024]; f zO8by  
int nRead; -#6*T,f0P(  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )mdNvb[*n  
{ ];;w/$zke  
nStartPos += fileAccessI.write(b,0,nRead); `1@[uWl  
//if(nThreadID == 1) W<VHv"?V  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BT3O_X`u  
} @E2nF|N  
ntV >m*^  
NO^t/(Z  
Utility.log("Thread " + nThreadID + " is over!"); J"rwWIxO*  
bDownOver = true;  uN 62>  
//nPos = fileAccessI.write (b,0,nRead); ?<'W~Rm6n  
} 1,QZnF!.x  
catch(Exception e){e.printStackTrace ();} z-5#bOABW  
} 0)5Sx /5'  
} 17)M.(qmuP  
5-HJ&Q  
,d>~='  
//打印回应的头信息 U_'q-*W  
public void logResponseHead(HttpURLConnection con) AFTed?(  
{ Pfx71*u,  
for(int i=1;;i++) _kN%6~+U  
{ )c/y07er  
String header=con.getHeaderFieldKey(i); !^fR8Tp9  
if(header!=null) sVd_O[  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z|*6fFE   
Utility.log(header+" : "+con.getHeaderField(header)); L0b] ^_ tI  
else }27Vh0v  
break; Vor9 ?F&w  
} IGT_ 5te  
} :QV6 z*#zD  
uk  f\*  
]a#]3(o]}  
public void splitterStop() FM"BTA:C  
{ ~#_$?_/(  
bStop = true; lMez!qx,=  
} N>%KV8>{L  
T1HiHvJ  
Xl6ZV,1=n7  
} 0DIM]PS  
kZ-~ ;fBe  
ws>Iyw.u  
/* %@93^q[\2  
**FileAccess.java NoZ4['NI\  
*//文件访问(定位,写) :TYzzl43  
package NetFox; 8;\tP29  
import java.io.*;  jnzz~:  
KH>sCEt  
f^sb0nU  
public class FileAccessI implements Serializable{ HcVs(]tIW  
EJaaW&>[  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rqe_zyc&  
RandomAccessFile oSavedFile; 6XL9 qb~X  
long nPos; >ha Ixs`9  
zMzf=~  
b%f2"e0g  
public FileAccessI() throws IOException 1=5'R/k  
{ zRoEx1  
this("",0); x ETVt q  
} R 4QwWSBJ  
e=)* O  
ZX6=D>)u  
public FileAccessI(String sName,long nPos) throws IOException MQH8Q$5D  
{ O\F^@;] F6  
oSavedFile = new RandomAccessFile(sName,"rw"); 0*IY%=i  
this.nPos = nPos; :'rZZeb'  
oSavedFile.seek(nPos); bA^: p3  
} [-Tt11  
%802H%+  
YZ:'8<  
public synchronized int write(byte[] b,int nStart,int nLen) m\Fb ,  
{ _& Uo|T  
int n = -1; M(WOxZ8  
try{ `(Q_ 65y  
oSavedFile.write(b,nStart,nLen); bc=u1=~w  
n = nLen; ~K#_'Ldrd  
} 4f[M$xU&h  
catch(IOException e) %3#I:>si  
{ LOUKUReE  
e.printStackTrace (); $17 v,  
} dms:i)L2  
&T/q0bwd  
e9hVX[uq  
return n; <_{4-Q>S3#  
} fRa-bqQ  
^AjYe<RU}  
,-I F++q  
} ]G o~]7(5|  
q{Ta?|x#  
:f !=_^}  
/* @uM3iO7&  
**SiteInfoBean.java k#:@fH4{PA  
*/ vl{_M*w ;  
package NetFox; m57tO X  
S}p&\w H  
yZ~eLWz  
public class SiteInfoBean { `_g?y)  
L!b0y7yR  
%=mwOoMk0L  
private String sSiteURL; //Site's URL C|~JPcl  
private String sFilePath; //Saved File's Path "K$Wh1<7  
private String sFileName; //Saved File's Name %f> |fs  
private int nSplitter; //Count of Splited Downloading File [cL U*:  
IU'!?XVo  
N" Jtg@w  
public SiteInfoBean() MHr0CYyb.  
{//nSplitter的缺省值为5 XG\a-dq[  
//default value of nSplitter is 5 Vh.;p.!e  
this("","","",5); OxHw1k  
}  Vq)gpR  
D.&eM4MZ  
~SR(K{nf#.  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K0DXOVT\  
{ E%2!C/+B  
sSiteURL= sURL; hzuMTKH9  
sFilePath = sPath; ND55`KT4  
sFileName = sName; o +QzQ+ Z  
this.nSplitter = nSpiltter; : ` 6$/DK  
id#k!*$7  
pJ$N@ID  
} WP@JrnxO\`  
< ;,S"e  
Th;gps%b  
public String getSSiteURL() Z/6'kE{l  
{ D@r n@N  
return sSiteURL; ! N"L`RWD  
} g"dZB2`C  
o~.o^0Y  
$YGIN7_Gg  
public void setSSiteURL(String value) U3|&Jee  
{ y%IG:kZ,  
sSiteURL = value; @(,{_c]  
} '^oGDlkr H  
^;CR0.4  
jY#(A23  
public String getSFilePath() )*TW\v`B  
{ kTi PZZI  
return sFilePath; ]dGr1 ncu  
} 4<3?al&  
i^s`6:rNu  
ghJ,s|lH  
public void setSFilePath(String value) 9?l?G GmQ  
{ \{M rQ2jd  
sFilePath = value; w[,?- Xm  
} gSv[4,hXd  
EDgob^>  
8W1K3[Jj<  
public String getSFileName() .y;\puNq  
{ bDh:!M  
return sFileName; 8%2rgA  
} WDoKbTv  
-M>K4*%K  
5}d/8tS  
public void setSFileName(String value) SN[L4}{  
{ '!yS72{$2  
sFileName = value; g@k#J"Q '[  
} ,2 g M-  
]4 K1%ZV  
l#5~ t|\  
public int getNSplitter() :uIi ?  
{ C$'D]fX  
return nSplitter; I4o =6ts  
} )4'x7Qg/  
j2 o1"  
B \_d5WJ<  
public void setNSplitter(int nCount) c+Q.?vJ  
{ Uaus>Frx.T  
nSplitter = nCount; U=&^H!LVY  
} !e:iB7<  
} (GCG/8s  
_f cS>/<a  
Fi mN?s  
/* >Bc> IO  
**Utility.java D`6iDi t  
*/ s}6+8fE"  
package NetFox; ze`1fO|%  
6iG(C.b  
Zy^=fM  
public class Utility { b2N6L2~V  
6X/wd k  
ev9; Ld  
public Utility() "\e:h| .G  
{ $}t=RW  
sLb8*fak  
1N8;)HLIBJ  
} tAF]2VV(e  
\tY"BC4.  
//线程睡眠 i+g~ Uj}h  
public static void sleep(int nSecond) ,V,f2W 4  
{ $@_{p*q  
try{ 93j{.0]X  
Thread.sleep(nSecond); M\Se_  
} a6%@d_A  
catch(Exception e) PgMbMH  
{ z~,mRgc$B  
e.printStackTrace (); |6aJwe+*  
} tQWWgLM  
} oL]mjo=jN  
\K;op2  
//日志 089 k.WG  
public static void log(String sMsg) -"=)z /S  
{ nX|Q~x]  
System.err.println(sMsg); H@GE)I>^@  
} o\Uu?.-<  
1BJ<m5/1%  
6B0# 4Qrv  
public static void log(int sMsg) IV'p~t  
{ c!It ^*  
System.err.println(sMsg); YTK^ijmU6x  
} MaO"#{i  
} gH[,Xx?BN!  
Ojq]HM6f  
zJ+3g!  
/* mzWP8Hlw  
**TestMethod.java l _+6=u  
*/ O sQkA2=  
package NetFox; #uSK#>H_!  
e+.\pe\  
l4rMk^>>  
public class TestMethod { ldGojnS  
W^es;5  
VPt9QL(  
public TestMethod() 4:7mK/Z  
{ ///xx/weblogic60b2_win.exe {^#2=`:)O  
try{ ?c]n^GvG  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )tS-.PrA-  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .h4\{|  
SiteFileFetch fileFetch = new SiteFileFetch(bean); t V03+&jF  
fileFetch.start(); kZLMtj-   
} 4U=75!>  
catch(Exception e){e.printStackTrace ();} Z<U>A   
]ab#q=  
XM/vDdR  
} Tkw;pb  
LH2PTW\b!6  
}u%"$[I}  
public static void main(String[] args) |S&5es-yW  
{ EF#QH _X  
new TestMethod(); 87V1#U^  
} UL( lf}M  
} j?6X1cMq  
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