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http断点续传简单实现(java)

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/* g;i>nzf  
**SiteFileFetch.java !e?=I  
*/ t.t$6+"5We  
package NetFox; |g;hXr#~  
import java.io.*; ?SK1*; i  
import java.net.*; !>TVDN>  
b2aPo M=  
"o*(i7T=n  
public class SiteFileFetch extends Thread { *NS:X7p!V  
;2(8&.  
- jfZLO4  
SiteInfoBean siteInfoBean = null; //文件信息Bean n[|&nv6x  
long[] nStartPos; //开始位置 1#qyD3K  
long[] nEndPos; //结束位置 D.kLx@Z  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 p[4KN(PyK  
long nFileLength; //文件长度 3 q^3znt  
boolean bFirst = true; //是否第一次取文件 %E}f7GT 4  
boolean bStop = false; //停止标志 6%sX<)n%]  
File tmpFile; //文件下载的临时信息 -%E+Yl{v  
DataOutputStream output; //输出到文件的输出流 y))d[ 1E  
!o+#T==p  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) %"r3{Hs  
public SiteFileFetch(SiteInfoBean bean) throws IOException (TM1(<j  
{  )o`|t  
siteInfoBean = bean; &|'1.^f@;E  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); #K.OJJaG  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 12U1DEd>-  
if(tmpFile.exists ()) 0k>bsn/ j  
{ m Y*JNx  
bFirst = false; _<yGen-  
read_nPos(); tV%:sk^d  
} wb~#=6Y  
else l ~CYxO  
{ dYrw&gn  
nStartPos = new long[bean.getNSplitter()]; -"Wp L2qD  
nEndPos = new long[bean.getNSplitter()]; 0-M.>fwZ=  
} {'C PLJ{R  
nsIx5UA_n  
Azv j(j  
: KhAf2A  
} 9_)*b  
&}_ $@  
lQj3# !1}  
public void run() R*VRxQ,h6+  
{ J,Du:|3o  
//获得文件长度 vnwS &;-k~  
//分割文件 kG@~;*;l  
//实例FileSplitterFetch 9dn~nnd'n  
//启动FileSplitterFetch线程 Jz(wXp  
//等待子线程返回 btoye \ rl  
try{ {&nL'R  
if(bFirst) uDvZ]Q|.  
{ ~,3+]ts='\  
nFileLength = getFileSize(); o *)>aw  
if(nFileLength == -1) `n7*6l<k~4  
{ Z`y%#B6x.  
System.err.println("File Length is not known!"); Y> ElE-  
} !LB#K?I  
else if(nFileLength == -2) ;)].Dj9  
{  G`8i{3:  
System.err.println("File is not access!"); bHZXMUewC  
} nb::,  
else ]awu7}C9Z  
{ luXcr H+w  
for(int i=0;i<nStartPos.length;i++) M:K5r7Q!yv  
{ mj:X'BVA  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); @px2/x  
} 1ml>  
for(int i=0;i<nEndPos.length-1;i++) *;@V5[^3I?  
{ W: R2e2  
nEndPos = nStartPos[i+1]; k|Mj|pqA  
} z/Z 0cM#  
nEndPos[nEndPos.length-1] = nFileLength;  #~QkS_  
} t)o!OEnE  
} g:<2yT  
7.U CX"  
MG6taOO!  
//启动子线程 UP]X,H~stU  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6+`+$s0  
for(int i=0;i<nStartPos.length;i++) Zpc R   
{ whFaL}2C  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d h5%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /`$9H|  
nStartPos,nEndPos,i); q$IgkL  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jd#g"a>zZ  
fileSplitterFetch.start(); "g}mxPe  
} x[L/d"Wf  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >F7v'-*{  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vU|=" #  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |hGi8  
nEndPos = " + nFileLength); kD1[6cJ!=.  
// fileSplitterFetch[nPos.length-1].start(); +9Vp<(  
QE8;Jk-  
)2vkaR  
//等待子线程结束 p+6L qk<  
//int count = 0; P(h[QAM  
//是否结束while循环 ^}Vx5[  
boolean breakWhile = false; e+416 ~X v  
X'[93 C|K  
sX_6qKUH  
while(!bStop) a(cZ]`s]*  
{ h|m>JDxn  
write_nPos(); w K)/m`{g  
Utility.sleep(500); o m9zb&{tu  
breakWhile = true; Ib V 7}  
oY Y?`<N#  
e:2e5gz  
for(int i=0;i<nStartPos.length;i++) +7%}SV 2)  
{ 4l)Q  
if(!fileSplitterFetch.bDownOver) 1=NP=ZB  
{ ; (0<5LQ  
breakWhile = false; FQ6jM~  
break; XQW9/AzNf  
} _}G1/`09#  
} /D@(o`a  
if(breakWhile) N5m+r.<;  
break; lxSCN6  
#\DKU@|h  
P[q`{TdV  
//count++; "WPFZw:9  
//if(count>4) WBOebv  
// siteStop(); %N.qu_,IZ  
} +2&+Gh.h  
+,wCV2>\3  
(zv)cw%  
System.err.println("文件下载结束!"); (>.+tq}  
} C{g Y*+  
catch(Exception e){e.printStackTrace ();} LS(J%\hMDm  
} b Ag>;e(  
j=>:{`*c  
/U1&#"P  
//获得文件长度 w]-,X`  
public long getFileSize() Gh.@l\|tf  
{ 7|vB\[s  
int nFileLength = -1; ;`CNe$y   
try{ T1Gy_ G/  
URL url = new URL(siteInfoBean.getSSiteURL()); FEoH$.4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;giW  
httpConnection.setRequestProperty("User-Agent","NetFox"); e/S^Rx4W  
+#$(>6Zu"{  
!/]vt?v#^  
int responseCode=httpConnection.getResponseCode(); )cF1?2  
if(responseCode>=400) 7"|j.Yq$H{  
{ J|Af`HJ  
processErrorCode(responseCode); =A yDVWpE  
return -2; //-2 represent access is error vH`m W`=  
} aM2[<m}  
*Y!c6eA  
9bE/7v  
String sHeader; }iu(-{Z  
'OERW|BO  
Z3jtq-y  
for(int i=1;;i++) 3B+ F'k&#  
{ aC9PlKI  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S zqY@  
//Utility.log(in.readLine()); BkO)hze  
sHeader=httpConnection.getHeaderFieldKey(i); C{"uz_Gh  
if(sHeader!=null) ?:8wDV  
{ "M`ehgCBr  
if(sHeader.equals("Content-Length")) c <T'_93  
{ VlLc[eVV  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !"dn!X  
break; gJn_Z7MgJ  
} UN,y /V  
} fxR}a,a  
else $ 2/T]  
break; ,vN0Jpf}\8  
} \q |n0>  
} @qGg=)T  
catch(IOException e){e.printStackTrace ();} vWM'}(  
catch(Exception e){e.printStackTrace ();} [+j39d.Q  
#c2InwZV  
s3., N|  
Utility.log(nFileLength); L.]mC !  
9F*],#ng  
.JJ^w!|>#  
return nFileLength; NbDfD3 1GK  
} eqFOPK5q  
a%h'utF{[  
#_zd`s3k  
//保存下载信息(文件指针位置) Qey6E9eCA  
private void write_nPos() DJm/:td  
{ 4Pm+0=E   
try{ Aj22t   
output = new DataOutputStream(new FileOutputStream(tmpFile)); WecJ^{g>r{  
output.writeInt(nStartPos.length); *C0gpEf9S  
for(int i=0;i<nStartPos.length;i++) CYxrKW l:'  
{ SdI/  
// output.writeLong(nPos); 7+h*&f3>  
output.writeLong(fileSplitterFetch.nStartPos); wn$:L9"YN  
output.writeLong(fileSplitterFetch.nEndPos); 4-YXXi}  
} N%2UL&w#B  
output.close(); Ya_4[vR<  
} /_,} o7@t~  
catch(IOException e){e.printStackTrace ();} _z3Hl?qk=  
catch(Exception e){e.printStackTrace ();} 5xEk 7g.  
} iN}BMd.U  
TF@HwF"#  
wq( m%F  
//读取保存的下载信息(文件指针位置) /@*J\0h(-  
private void read_nPos() O>![IH(L  
{ 0M?nXHA[  
try{ vGk}r  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rLzYkZ  
int nCount = input.readInt(); >QusXD"L>  
nStartPos = new long[nCount]; )~](qLSl  
nEndPos = new long[nCount]; ^1%gQ@P  
for(int i=0;i<nStartPos.length;i++) M?UlC   
{ OoFQ@zE7%  
nStartPos = input.readLong(); c0H8FF3  
nEndPos = input.readLong(); ~'4:{xH  
} >:ZlYZ6sI  
input.close(); GC3:ZpV`  
} kt";Jx  
catch(IOException e){e.printStackTrace ();} b=#3p  
catch(Exception e){e.printStackTrace ();} ;5*)kX  
} !6wbg  
G0^O7w^5  
 MRB>(}  
private void processErrorCode(int nErrorCode) 3xW;qNj:!l  
{ ;'Pi(TA)  
System.err.println("Error Code : " + nErrorCode); n ^T_pqV?X  
} TwZvz[u  
qdn\8Pn  
q5$z:'zE  
//停止文件下载 mX8A XWIa  
public void siteStop() vWJhSpC[  
{ 5T[9|zJs  
bStop = true; ==psPyLF@  
for(int i=0;i<nStartPos.length;i++) i*9l  
fileSplitterFetch.splitterStop(); `TkI yGr  
x*#F|N4~',  
1%L* 9>e  
} ]`D(/l'  
} ^}2 ie|  
//负责部分文件的抓取 Qa,^;hZWS  
**FileSplitterFetch.java !U"1ZsO)l  
*/ t9&z|?Vz  
package NetFox; E(T6s^8  
xNNoB/DR  
ta+'*@V +G  
import java.io.*; M} IRagm  
import java.net.*; 6'Sc=;;:  
Po[u6K2&  
}lgqRg)F9[  
public class FileSplitterFetch extends Thread { X$O,L[] 4  
6,'!z ?d%  
@=c{GAj  
String sURL; //File URL O_f|R1G5z  
long nStartPos; //File Snippet Start Position /$hfd?L  
long nEndPos; //File Snippet End Position `d=$9Pi  
int nThreadID; //Thread's ID EX>|+zYL  
boolean bDownOver = false; //Downing is over bOCdf"!g  
boolean bStop = false; //Stop identical {Izg1 N  
FileAccessI fileAccessI = null; //File Access interface ?ng?>!  
7"f$;CN?~  
`07u}]d8  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fB5Bh;K  
{ ay2 m!s Q  
this.sURL = sURL; Rg&6J#h  
this.nStartPos = nStart; z[Kxy1,  
this.nEndPos = nEnd; `h M:U  
nThreadID = id; Ep}KIBBO  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O.=~/!(  
} {6<7M  
)o[ O%b  
yI9l*'  
public void run() xZ@H{):  
{ b?oT|@  
while(nStartPos < nEndPos && !bStop) q[]!V0Ek10  
{ $JTy`g0>x  
1h\:Lj  
oKTIoTb  
try{ _QtqQ~f  
URL url = new URL(sURL); 9`^VuC'  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?B %y)K  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3V`K^X3  
String sProperty = "bytes="+nStartPos+"-"; vi0% jsI  
httpConnection.setRequestProperty("RANGE",sProperty); u+s#Fee I  
Utility.log(sProperty); L6j 5pI  
$*%Ml+H-  
uL b- NxQ-  
InputStream input = httpConnection.getInputStream(); dUn8Xqj1  
//logResponseHead(httpConnection); o})4Jt1vj  
uw+v]y  
8Es]WR5 ^  
byte[] b = new byte[1024]; @hm %0L  
int nRead; TE*$NxQ 2  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0+8ThZ?n  
{ %_1~z[Dv  
nStartPos += fileAccessI.write(b,0,nRead); /-$`GT?l  
//if(nThreadID == 1) Fm-W@  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3h"; 2  
} O6;>]/`  
m7kDxs(KO  
U:MkA(S%c  
Utility.log("Thread " + nThreadID + " is over!"); <_ */  
bDownOver = true; _\"P<+!  
//nPos = fileAccessI.write (b,0,nRead); N{/q p  
} X3]E8)645N  
catch(Exception e){e.printStackTrace ();} |.:O$/ Tt[  
} %>i7A?L  
} mo#4jtCE  
pP?J(0Q~  
T] EXm/  
//打印回应的头信息 Sct-,K%i  
public void logResponseHead(HttpURLConnection con) Vw9^otJu  
{ * @G4i  
for(int i=1;;i++) 5G){7]P+r"  
{ *^c4q|G.-  
String header=con.getHeaderFieldKey(i); v !@/  
if(header!=null) ItKwB+my  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1elcP`N1  
Utility.log(header+" : "+con.getHeaderField(header)); {L$b$u$7:  
else W\U zw,vI  
break; Oe$cM=Yf  
} p>K'6lCa  
} :M|c,SQK  
U3kf$nbV/J  
FEaf&'G]  
public void splitterStop() [X^JV/R  
{ v.6" <nT2  
bStop = true; =]xNpX)  
} .1I];Cy0D  
r'&9'rir2  
9aZ3W<N`M  
} r=L9x/r  
qR]4m]o  
B[4y(Im  
/* $'9r=#EH  
**FileAccess.java DGHX:Ft#  
*//文件访问(定位,写) 83i%3[L  
package NetFox; (^a;2j9  
import java.io.*; L{^DZg|E  
pJa FPO..|  
ZFW}Vnl  
public class FileAccessI implements Serializable{ `y YgL@Zt  
Oku4EJFJ  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m3_e]v3{o  
RandomAccessFile oSavedFile; P603P  
long nPos; FbFUZ^Zj  
=#Vdz=.  
fwsq:  
public FileAccessI() throws IOException ;S?1E:\av  
{ K/\#FJno  
this("",0); ;xB"D0~,1  
} D<++6HN&#  
Mh+'f 93  
>j`*-(`2fa  
public FileAccessI(String sName,long nPos) throws IOException i;)g0}x`  
{ 0BaL!^>  
oSavedFile = new RandomAccessFile(sName,"rw"); j{U-=[$'  
this.nPos = nPos; /=e[(5X|O  
oSavedFile.seek(nPos); sWavxh8A  
} ziH2<@  
j~Gu;%tq  
bq(*r:`"  
public synchronized int write(byte[] b,int nStart,int nLen) [PX'Jer  
{ BLaX p0  
int n = -1; z%Z}vWn  
try{ &g& &-=7)  
oSavedFile.write(b,nStart,nLen); =l7LEkR  
n = nLen; )&R;!#;5  
} ['R=@.  
catch(IOException e) hLm9"N'Pf  
{ B.P64"w  
e.printStackTrace (); "BFW&<1  
} [tD*\\IA  
iBo-ANnK9  
Uw&+zJ  
return n; <q[ *kr  
} 'E&K%/d  
~:t2@z4p  
p\-.DRwT`  
} C>K/C!5?  
s}z,{Y$-t  
X!2|_  
/* }SN'*w@E  
**SiteInfoBean.java oTa! F;I  
*/  gA[M  
package NetFox; 4l$8lYi  
ycE<7W  
@nT8[v  
public class SiteInfoBean { (QRl -| +  
l&|{uk  
!k s<VJh  
private String sSiteURL; //Site's URL vy#c(:UQR  
private String sFilePath; //Saved File's Path $`=?Nb@@#  
private String sFileName; //Saved File's Name YKx0Zs  
private int nSplitter; //Count of Splited Downloading File [ThzLk#m  
bs`/k&'  
wcL0#[)  
public SiteInfoBean() ~o2{Wn["  
{//nSplitter的缺省值为5 Aj`4uFhiL  
//default value of nSplitter is 5 ffB]4  
this("","","",5); xK y<o  
} A&M/W'$s  
>u/yp[Ky  
(w^&NU'e  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ` q@~78`  
{ \)#3S $L~  
sSiteURL= sURL; &qpA<F@7  
sFilePath = sPath; 3+$O#>  
sFileName = sName; 8/F2V?iT  
this.nSplitter = nSpiltter; R|M:6]}   
s24H.>Z  
C {,d4KG  
} (i?^g &  
*FE<'+%  
[ho'Pc3A<  
public String getSSiteURL() XM 7zA^-  
{  WcJ{}V9  
return sSiteURL; tV,zz;* Oe  
} y@Or2bO#  
'q-h kN  
.F6#s  
public void setSSiteURL(String value) <qy+@t  
{ .iS]aJJ  
sSiteURL = value; xD#/@E1'Y  
} .iYgRW=T  
@t^ 2/H ?O  
<|_Ey)1 6  
public String getSFilePath() JQ1VCG  
{ ?yU#'`q  
return sFilePath; a;zcAeX  
}  {Eb6.  
oaK~:'  
B)|s.Ez  
public void setSFilePath(String value) -s1VlS/  
{ d{m0uX56  
sFilePath = value; Fi`:G}   
} h P1|l  
xV6j6k  
hf-S6PEsM  
public String getSFileName() ,]Ma ,2  
{ P}I*SV0  
return sFileName; [K KoEZ  
} `Qhh{  
k$2Y)  
6GN'rVr!Z  
public void setSFileName(String value) ;uDFd04w [  
{ +W1rm$Q  
sFileName = value; k8JPu"R  
} 9x1Dyz 2?F  
PA/6l"-`3  
b1OB'P8  
public int getNSplitter() DNy)\+[  
{ # 9t/j`{  
return nSplitter; @e7+d@ O<  
} 3IkG*enI  
!:8!\gE ^P  
6\K)\  
public void setNSplitter(int nCount) *+z({S_Nv  
{ ;1 fML,8  
nSplitter = nCount; Pla EI p  
} 88K*d8m  
} S!]}}fKEFm  
3:( `#YY  
rij[ZrJ  
/* 4Uiqi{}  
**Utility.java z|2liQrf+  
*/ KOQTvJ_#  
package NetFox; Bz{ g4!ku  
/b|sv$BN  
xpk|?/6  
public class Utility { {;zPW!G  
4l*&3Ar  
v+G:,Tc"  
public Utility() ;D1IhDC  
{ +\%zy=  
xlLS`  
rBf?kDt6l  
} Ydx5kUJV<  
;k8}D*?8  
//线程睡眠 hA8 zXk/'8  
public static void sleep(int nSecond) Z:_y,( 1Q  
{ ?zEF?LJoK  
try{ (AYD @  
Thread.sleep(nSecond); 4=Ey\Px  
} 1|VJND  
catch(Exception e) NP8TF*5V  
{ /HRaX!|E#  
e.printStackTrace (); x _K%  
} ~ #CCRUhM  
} J (h>  
1GdD  
//日志 Q Y'-]  
public static void log(String sMsg) @2gMtf?<  
{ K5SO($  
System.err.println(sMsg); YSgF'qq\  
} )VT/kIq-U  
{/<&  
(=j!P*  
public static void log(int sMsg) w^gh&E  
{ d%3BJ+J  
System.err.println(sMsg); U\ued=H  
} F 4/Uu"J:  
} R=PzR;8  
^ne8~ ;Q  
7,TWCVap  
/* ~|rkt`8p  
**TestMethod.java 5WT\0]RUa  
*/ ' T]oV~H  
package NetFox; `?x$J 6p  
dK: "  
e`r;`a&  
public class TestMethod { {P&^Erx  
 o 2  
8:xo ~Vc  
public TestMethod() pC-OZ0  
{ ///xx/weblogic60b2_win.exe =f!M=D  
try{ ]aNnY?qW5  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <Z' hZ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i1\2lh$  
SiteFileFetch fileFetch = new SiteFileFetch(bean); BvF_9  
fileFetch.start(); #=(op?]  
} Ef.4.iDJrR  
catch(Exception e){e.printStackTrace ();} SK52.xXJ  
4Z }{hc\J  
ItADO'M  
} - (1\ `g07  
T;@>O^  
9#ft;c  
public static void main(String[] args) I?>T"nV +'  
{ )\vHIXnfJ1  
new TestMethod(); {R;M`EU>  
} yU,xcq~l  
} p'~5[JR:  
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