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http断点续传简单实现(java)

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/* F!R2_89iy  
**SiteFileFetch.java 0ny{)Sd6um  
*/ DyX0 xx^  
package NetFox; @ KJV1t`  
import java.io.*; ?>)yKa#U  
import java.net.*; /| f[us-w  
lM&UFEl-\  
?waebuj>  
public class SiteFileFetch extends Thread { ]^ !}*  
U?EG6t  
(fd[P|G_]  
SiteInfoBean siteInfoBean = null; //文件信息Bean PSEWL6=]N  
long[] nStartPos; //开始位置 ?360SQ<  
long[] nEndPos; //结束位置 w -dI<s  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 [|z'"Gk{  
long nFileLength; //文件长度 WgZ@N  
boolean bFirst = true; //是否第一次取文件 \P@S"QO  
boolean bStop = false; //停止标志 pE(sV{PD  
File tmpFile; //文件下载的临时信息 lbofF==(  
DataOutputStream output; //输出到文件的输出流 x:C@)CAr  
!OQuEJR  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) EOQaY  
public SiteFileFetch(SiteInfoBean bean) throws IOException +I.v!P!^  
{ Fo LDMx(  
siteInfoBean = bean; R_9 o!s TZ  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); =SL^>HS.fo  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); S| "TP\o  
if(tmpFile.exists ()) JilKZQmk  
{ R25-/6_V>  
bFirst = false; }6@%((9E 2  
read_nPos(); W+/2c4$F3  
} +Wd L  
else 4L $};L  
{ /xf.\Z7<  
nStartPos = new long[bean.getNSplitter()]; U TS{H  
nEndPos = new long[bean.getNSplitter()]; wKLN:aRF2  
} D{3fhPNU<b  
P|v ?  
%\l0-RA@<  
&&*wmnWCS{  
} iW-t}}Z>B  
Y)v%  
K]MzP|T,  
public void run() Uk|9@Auav  
{ hvL6zCi  
//获得文件长度 :^.u-bHI  
//分割文件 b8e*Pv/  
//实例FileSplitterFetch CL )%p"[x  
//启动FileSplitterFetch线程 _Ua PwJ  
//等待子线程返回 XJ _%!  
try{ sHF%=Vu  
if(bFirst) (Y>U6  
{ ) _ #T c  
nFileLength = getFileSize(); vS2(Q0+TZi  
if(nFileLength == -1) rSbQ}O4V  
{ lkyJ;}_**  
System.err.println("File Length is not known!"); Y& m<lnB  
} hN}5u"pS  
else if(nFileLength == -2) ?Cc$]  
{ x;*VCs  
System.err.println("File is not access!"); y "<JE<X  
} }Uq/kei^P  
else ![j(o!6&  
{ ;wp W2%&  
for(int i=0;i<nStartPos.length;i++) R<t&F\>  
{ 8db6(Q~P  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); HK? Foo?  
} `} ZL'\G  
for(int i=0;i<nEndPos.length-1;i++) WE7>?H*Ro  
{ R,XD6'Q  
nEndPos = nStartPos[i+1]; bf{Ep=-  
} 9/^d~ ZO  
nEndPos[nEndPos.length-1] = nFileLength; we @Yw6<  
} [!5l0{0  
} 3k`NNA  
jw/ wcP  
9.jG\i  
//启动子线程 x vHOY:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "_ Zh5 g  
for(int i=0;i<nStartPos.length;i++) mJ/^BT]  
{ p~ mN2x]  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :0{AP_tvcC  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -<_+-t  
nStartPos,nEndPos,i); ))$ CEh"X  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *?s/Ho &'  
fileSplitterFetch.start(); (1OW6xtfG  
} j`Tm\!q  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #dL5x{gV=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); uTxX`vH@!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I<IC-k"Y  
nEndPos = " + nFileLength); McO@p=M  
// fileSplitterFetch[nPos.length-1].start(); 9j9Y Q2  
O#A8t<f|M  
0,+EV,  
//等待子线程结束 "Fo  
//int count = 0; rE9Ta8j6  
//是否结束while循环 3{I=.mUUm  
boolean breakWhile = false; wrhBH;3  
:A,O(   
e?|d9;BO  
while(!bStop) 5R& x{jf$  
{ & %@/Dwr  
write_nPos(); wbn^R'  
Utility.sleep(500); ?]759,Q3L  
breakWhile = true; ;B,nzx(L  
$gXkx D  
`4se7{'UK`  
for(int i=0;i<nStartPos.length;i++) +!D=SnBGs  
{ tuX =o  
if(!fileSplitterFetch.bDownOver) @#'yPV1  
{ z&\Il#'\m+  
breakWhile = false; {(8U8f<'=y  
break; YWybPD4\(  
} gF$1wV]e  
} !k4 }v'=  
if(breakWhile) AEiWL.*.  
break; SjFF=ib  
HCI'q\\  
yIn/Y0No  
//count++; gNG0k$nP  
//if(count>4) vsOdp:Yp9!  
// siteStop(); eV@4VxaZ  
} kq-mr  
g| _HcaW  
$1:}(nO,  
System.err.println("文件下载结束!"); 9[6G8;<D&  
} _Ac/ir[,:  
catch(Exception e){e.printStackTrace ();} WK/b=p|#o  
} f>.` xC{  
v)wY  
FF5tPHB  
//获得文件长度 6:e}v'q{  
public long getFileSize() nL "g23  
{ kxt\{iy4  
int nFileLength = -1; 9/@FADh  
try{ ~Rx~g  
URL url = new URL(siteInfoBean.getSSiteURL()); z36brv<_'p  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PmuEL@'^ U  
httpConnection.setRequestProperty("User-Agent","NetFox"); N` @W%  
7-g]A2N  
$%N;d>[U,  
int responseCode=httpConnection.getResponseCode(); u&hDjE  
if(responseCode>=400) 9Ba%=  
{ F(?Fz8  
processErrorCode(responseCode); [,.[gWA  
return -2; //-2 represent access is error Vu_7uSp,)  
} My'9S2Y8nv  
v9X7-GJ~  
`</=AY>  
String sHeader; LZ=wz.'u  
<(u3+`f1s  
iX0]g45o  
for(int i=1;;i++) }z9I`6[  
{ 7UeE(=Hr5  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,n /SDEL  
//Utility.log(in.readLine()); )&b}^1  
sHeader=httpConnection.getHeaderFieldKey(i); LS R_x$G+t  
if(sHeader!=null) /h.:br?M#P  
{ ~Hp#6+  
if(sHeader.equals("Content-Length")) 48*Oh2BA  
{ Gd]5xl HRU  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #U\&i`  
break; Huc3|~9  
} YD0vfwh  
} yBXkN&1=%;  
else P>yG/:W;  
break; Zi2Eu4p l{  
} i} NkHEK  
} Y&1!Z*OL;  
catch(IOException e){e.printStackTrace ();} @'k,\$/  
catch(Exception e){e.printStackTrace ();} vu !j{%GO  
9XJ9~I?  
.P |+oYT&g  
Utility.log(nFileLength); ,u8ZS|9  
{Oc?C:aI=  
t(uB66(_F  
return nFileLength; ~#IWM+I  
} "Gi+zkVm  
|g: '')>[  
X-*KQ+ ?  
//保存下载信息(文件指针位置) &"~,V6,q  
private void write_nPos() .&* ({UM  
{ mlsvP%[f.  
try{ vkNZ -`+I  
output = new DataOutputStream(new FileOutputStream(tmpFile)); p3,(*eZ  
output.writeInt(nStartPos.length); n;S0fg  
for(int i=0;i<nStartPos.length;i++) L:k@BCQM  
{ 7>W+Uq  
// output.writeLong(nPos); 9}'l=b:Jms  
output.writeLong(fileSplitterFetch.nStartPos); O|^6UH  
output.writeLong(fileSplitterFetch.nEndPos); 4X(1   
} >h/)r6  
output.close(); _^ CQ*+F  
} <.?^LT  
catch(IOException e){e.printStackTrace ();} z Et6  
catch(Exception e){e.printStackTrace ();} :3E8`q~c1  
} ;ZE<6;#3IP  
^G7n#  
Rpa A)R,  
//读取保存的下载信息(文件指针位置) $@ T6g  
private void read_nPos() qw Kh,[]  
{ gOES2 4$2  
try{ ATXx? b8h  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?=|) n%  
int nCount = input.readInt(); 2S7H_qo$  
nStartPos = new long[nCount]; m\}\RnZu  
nEndPos = new long[nCount]; K_<lO,[S  
for(int i=0;i<nStartPos.length;i++) Bcd0   
{ >gS5[`xRE  
nStartPos = input.readLong(); ;k63RNT,M&  
nEndPos = input.readLong(); ] fwTi(4y  
} pO7{3%  
input.close(); 4/mj"PBKL  
} vt(}ga  
catch(IOException e){e.printStackTrace ();} F_M~!]<na  
catch(Exception e){e.printStackTrace ();} +"N<-  
} ~YT>:Np  
>FE QtD~F  
u}@% 70A  
private void processErrorCode(int nErrorCode) c-3YSrY  
{ )n3bi QL_  
System.err.println("Error Code : " + nErrorCode); 4%c7#AX[T  
} B9;,A;E};  
9cw4tqTm  
?Ss RN jeL  
//停止文件下载 S*DBY~pZy  
public void siteStop() x/jN& ;"/  
{ Do[ F+Y  
bStop = true; zvQ^f@lq2  
for(int i=0;i<nStartPos.length;i++) Sj]T{3mi  
fileSplitterFetch.splitterStop(); D.oS8'   
R(7X}*@X  
|]2eGrGj4  
} 3Oig/KZ  
} 2}xFv2X  
//负责部分文件的抓取 |Z^c #R  
**FileSplitterFetch.java s_Ge22BZ  
*/ 1+PNy d  
package NetFox; E#HU?<q8  
_>:=<xyOq  
T$8$9D_u  
import java.io.*; :BZx ) HxQ  
import java.net.*; oRJP5Y5na  
;Cp/2A}Xx  
[2H(yLwO  
public class FileSplitterFetch extends Thread { N- ?|]4e/  
4[f7X4d$  
x x`8>2T#e  
String sURL; //File URL #*;fQ&p  
long nStartPos; //File Snippet Start Position me}Gb a  
long nEndPos; //File Snippet End Position C{I8Pio{b  
int nThreadID; //Thread's ID c_8mQ  
boolean bDownOver = false; //Downing is over ; HLMU36q  
boolean bStop = false; //Stop identical <J_,9&\J  
FileAccessI fileAccessI = null; //File Access interface w\8r h\Mvh  
Y[8co<p  
efAahH  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }RP9%n^  
{ n-| i  
this.sURL = sURL; ]@<3 6ByM  
this.nStartPos = nStart; :Ro" 0/d  
this.nEndPos = nEnd; RxDxLU2kt  
nThreadID = id; yfw>y=/p  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RT+30Q?  
} %RD7=Z-z  
BQfAen]  
Jv{"R!e"P  
public void run() 0 f#a_  
{ <T2~xn  
while(nStartPos < nEndPos && !bStop) R7;rBEt8  
{ Z_4H2HseL  
uRq#pYn@  
Er+3S@sfq,  
try{ s? \9i6  
URL url = new URL(sURL); fOjt` ~ToI  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $q@RHcj  
httpConnection.setRequestProperty("User-Agent","NetFox"); ) eGu4iEPM  
String sProperty = "bytes="+nStartPos+"-"; 02 c.;ka3  
httpConnection.setRequestProperty("RANGE",sProperty); yW=hnV{  
Utility.log(sProperty); `R=_t]ie  
9oau _Q#  
)1yUV*6  
InputStream input = httpConnection.getInputStream(); D!E 9@*Lf  
//logResponseHead(httpConnection); ]B.,7  
G`JwAy r'  
yLa5tv/  
byte[] b = new byte[1024]; g #<?OFl  
int nRead; = ]HJa  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &T/9y W[L  
{ -0J<R;cVs  
nStartPos += fileAccessI.write(b,0,nRead); j]F3[gpc  
//if(nThreadID == 1) LGg x.Z  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q_|S^hx Q  
} \w\47/k{  
Va[dZeoy  
`&Of82*w  
Utility.log("Thread " + nThreadID + " is over!"); aKU8" 5  
bDownOver = true; cM'[;u  
//nPos = fileAccessI.write (b,0,nRead); }PD(kk6fX  
} Gqz)='  
catch(Exception e){e.printStackTrace ();} J<:D~@qq  
} :bF2b..XOu  
} %|6Q7'@p  
3'@jRK  
>U Ich  
//打印回应的头信息 g:6}zHK  
public void logResponseHead(HttpURLConnection con) ]X;*\-  
{ g<0%-p  
for(int i=1;;i++) LFM5W&?  
{ (IQ L`3f%  
String header=con.getHeaderFieldKey(i); XK9*,WA9r  
if(header!=null) R\=\6("  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 52R.L9Ai  
Utility.log(header+" : "+con.getHeaderField(header)); RuEnr7gi  
else *wZV*)}  
break; -EIMh^  
} hnL gsz  
} 7}7C0mV3  
BCDf9]X  
]qG5 Ne _  
public void splitterStop() n~cm?"  
{ <yaw9k+P  
bStop = true; IG@&l0ARL  
} 0_Z|y/I.  
 Jy[8,X  
aZ0iwMK  
} E6\~/=X=%  
[?o v J  
{'bkU9+  
/* )s[S.`S Tz  
**FileAccess.java H4",r5qw:  
*//文件访问(定位,写) 6#63D>OWp  
package NetFox; 4U1fPyt  
import java.io.*; [*E.G~IS`  
:v ~q  
~l(tl[  
public class FileAccessI implements Serializable{ B9Tztg  
\B +SzW  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oa|*-nw  
RandomAccessFile oSavedFile; weadY,-H8  
long nPos; _@?Jx/`;bk  
03\8e?$  
90k|u'ikOp  
public FileAccessI() throws IOException rSCX$ @@F  
{ `%:(IGxz  
this("",0); Yzx0[_'u  
} >V=@[B(0  
*J5euA5=  
"r3s'\  
public FileAccessI(String sName,long nPos) throws IOException jmVy4* P_  
{ \(t>(4s_~  
oSavedFile = new RandomAccessFile(sName,"rw"); W%QtJB1)  
this.nPos = nPos; D??/=`|8  
oSavedFile.seek(nPos); Gf.o{  
} #u(,#(P'#  
AdW7 vn  
X.5LB!I)  
public synchronized int write(byte[] b,int nStart,int nLen) p arG  
{ eV}Tx;1|}  
int n = -1; RxG./GY  
try{ @n'ss!h  
oSavedFile.write(b,nStart,nLen); N2Hb19/k  
n = nLen; \`# 0,pLr  
} HBGA lZ  
catch(IOException e) Upen/1bA  
{ S*@0%|Q4r  
e.printStackTrace (); U MIZ:*j  
} T<GD!j(  
.Q@'Ob`  
V2skr_1  
return n; [)c|oh%  
} 84cH|j`w  
=i %w_ e  
RL8 wSK  
} ?saVk7Z[|5  
Ka2tr]+s  
<cjTn:w  
/* aBLb i  
**SiteInfoBean.java L#b Q`t  
*/ ay[*b_f  
package NetFox; Lwk-  
bUL9*{>G  
iP_Xr~w  
public class SiteInfoBean { ^<+heX  
^Z+D7Q  
>1zzDd_  
private String sSiteURL; //Site's URL  p$v +L  
private String sFilePath; //Saved File's Path ,KaWP  
private String sFileName; //Saved File's Name EOC"a}Cq-  
private int nSplitter; //Count of Splited Downloading File fdW={}~  
ZM!~M>B9R  
uMZf9XUE  
public SiteInfoBean() W<l(C!{  
{//nSplitter的缺省值为5 brot&S2P><  
//default value of nSplitter is 5 T6#GlO)8)  
this("","","",5); JFdzA  
} [)u{-  
:E*U*#h/  
IBsn>*ja<  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z_+No :F7I  
{ `^{P,N>X  
sSiteURL= sURL; CgE5;O  
sFilePath = sPath; zf u78  
sFileName = sName; (DAJ(r~  
this.nSplitter = nSpiltter; 5)6%D  
+06j+I  
lNAHn<ht  
} WQ`T'k#ESW  
ij5YV3  
KR0 x[#.*  
public String getSSiteURL() %Ski5q  
{ L\DaZ(Y  
return sSiteURL; < Ifnf 6~  
} b*fflJ  
![%,pip2/&  
b"9,DQB=i  
public void setSSiteURL(String value) N4-J !r@#~  
{ ,iUx'U  
sSiteURL = value; l0)uu4|  
} #m>mYp8E.5  
wYG0*!Vj  
\>k+Oyj  
public String getSFilePath() 7 i/Cax  
{ BZ9iy~  
return sFilePath; "dTXT  
} ~yN,FpD  
{c; 3$  
dW68lVWq_  
public void setSFilePath(String value) ]+P &Y:   
{ W9"I++~f  
sFilePath = value; =ndKG5  
} ak [)+_k_  
@( l`_Wx  
O6]~5&8U.  
public String getSFileName() W[s>TDc`v  
{ AF6'JxG7  
return sFileName; ba13^;fm#  
} H=C;g)R  
P+h&tXZn8  
= @o}  
public void setSFileName(String value) 63=m11 Z4  
{ (P-<9y@  
sFileName = value; _(foJRr  
} s=4.Ovd\  
+&@0;zSga  
UEUTu}4y  
public int getNSplitter() ig{5 ]wZ(  
{ -s"lW 7N^  
return nSplitter; iXFaQ  
} A$cbH.  
h;->i]  
-yeT$P&|  
public void setNSplitter(int nCount) ZI7<E  
{ 6tguy  
nSplitter = nCount; c^y 1s*  
} _rd{cvdR  
} -}@9lhS,  
{W]jVh p  
xFZq6si?  
/* s?Kn,6Y  
**Utility.java }T,uw8?f!  
*/ >YLm]7v}  
package NetFox; v &n &i?  
g%trGW3{-  
@#apOoVW>  
public class Utility { Sls> OIc  
/Ny&;Y  
+Sfv.6~v  
public Utility() o6 /?WR9  
{ Cmj)CJ-  
q@:&^CS  
LxT] -  
} 3nO|A: t  
n>WS@b/o  
//线程睡眠 XJ;/ kR  
public static void sleep(int nSecond) 00i9yC8@6  
{ (agdgy:#  
try{ Xc!w y9m  
Thread.sleep(nSecond); 3>+;G4  
} mX89^  
catch(Exception e) 9[`6f8S_$  
{ :9}*p@  
e.printStackTrace (); |w DCIHzQ  
} n[@Ur2&)  
} 9=|5-? ^  
!r<7]nwV  
//日志 lK-I[i!  
public static void log(String sMsg) PO&`r r  
{ f@0`,  
System.err.println(sMsg); c,@6MeKHq  
} cF6|IlhO  
duI8^&|  
\cG'3\GI  
public static void log(int sMsg) \1Zf Sc  
{ C7{wI`~  
System.err.println(sMsg); x+pFu5,  
} Ero3A'f  
} o#i {/# oF  
(rJvE*  
Gkl#s7'  
/* Ot?rsr  
**TestMethod.java fOVRtSls  
*/ xk/(| f{L  
package NetFox; > L%%B-  
DxlX-  
{)mlXo(On  
public class TestMethod { :|a[6Uwl\V  
ydt1ED0Q-  
QUt!fF@t  
public TestMethod() 3r\QLIr L8  
{ ///xx/weblogic60b2_win.exe ZU`"^FQ3A  
try{ W>~V?%F&'  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X\;y;pmRH  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P.o W#Je  
SiteFileFetch fileFetch = new SiteFileFetch(bean); .eE5pyw+C  
fileFetch.start(); $)U RY~;i  
} @9-qqU@  
catch(Exception e){e.printStackTrace ();} 4t":WutC  
1 !sYd@iD@  
"P6MLf1  
} /=N`P &R#  
,0~=9dR  
y.zW>Mfl  
public static void main(String[] args) { }z7N~  
{ r* U6govky  
new TestMethod(); Z1Wra-g  
} B4kIcHA  
} O'k"6sBb  
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