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http断点续传简单实现(java)

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/* ``l7|b jJ  
**SiteFileFetch.java Yo`#G-]  
*/ 8T3j/ D<r  
package NetFox; KHK|Zu#k '  
import java.io.*; 7#\\Ava$T  
import java.net.*; zqd_^  
^pAgo B  
#0yU K5J  
public class SiteFileFetch extends Thread { +mc0:e{WF  
?f9@  
N{6 - rR  
SiteInfoBean siteInfoBean = null; //文件信息Bean Ni"M.O);t  
long[] nStartPos; //开始位置 6rBXC <Z  
long[] nEndPos; //结束位置 "RZV v~BD  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Ygwej2  
long nFileLength; //文件长度 s@Q, wa(  
boolean bFirst = true; //是否第一次取文件 ;QVX'?  
boolean bStop = false; //停止标志 C7|z DJ_  
File tmpFile; //文件下载的临时信息 U _QCe+  
DataOutputStream output; //输出到文件的输出流 %hEhZW{:  
IaDN[:SX  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) =#tQhg,_  
public SiteFileFetch(SiteInfoBean bean) throws IOException lwY2zX&%)/  
{ HY (|31  
siteInfoBean = bean; "mBX$t'gb  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); cjTV~(i'4A  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); /hx|KC&:e  
if(tmpFile.exists ()) v61'fQ1Qg!  
{ @Yv+L)  
bFirst = false;  >^<%9{  
read_nPos(); 0vu$dxb[  
} ?8{x/y:  
else Tc{n]TV  
{ z?9vbx  
nStartPos = new long[bean.getNSplitter()]; D #<)q)  
nEndPos = new long[bean.getNSplitter()]; =wd=TX/  
} Klw\  
]VarO'  
rKK{*%n  
B~[}E]WEK  
} y@\R$`0J  
WyO7,Qr\   
!!jitFHzb  
public void run() "`QI2{!l  
{ 7U:-zfq  
//获得文件长度 %Ls5:Z=  
//分割文件 9GH11B_A  
//实例FileSplitterFetch tH7@oV;  
//启动FileSplitterFetch线程 YlF<S49loC  
//等待子线程返回 @Ido6Z7  
try{ 6 /A#P$G  
if(bFirst) V l,V  
{ }"V$li  
nFileLength = getFileSize(); L<GF1I)  
if(nFileLength == -1) `7f><p/q  
{ dtXA EL\q  
System.err.println("File Length is not known!"); dZMOgZ.!yr  
} Y? 1 3_~ K  
else if(nFileLength == -2)  k|Xxr  
{ r)9&'m.:  
System.err.println("File is not access!"); zc}qAy'<  
} t[L_n m5-  
else BA1|%:.   
{ gM0^k6bB8  
for(int i=0;i<nStartPos.length;i++) 7W{xK'|]  
{ {~Q9jg(A  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); \R m2c8Z2  
} v#HaZT]u  
for(int i=0;i<nEndPos.length-1;i++) Awip qDAu  
{ $r>\y (W  
nEndPos = nStartPos[i+1]; dn"&j1@KY  
} `|t X[':  
nEndPos[nEndPos.length-1] = nFileLength; 72YL   
} efK3{   
} d]kP@flOV  
>z(AQ  
-zzM!1@F  
//启动子线程 vf |lF9@U  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !I 7bxDzK$  
for(int i=0;i<nStartPos.length;i++) ~If{`zWoC  
{ 0:,8Ce  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yq?7!X  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /SXms'C  
nStartPos,nEndPos,i); _fVC\18T  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S%+$  
fileSplitterFetch.start(); ]~')OSjw  
} %(9BWO  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &WqKsH$  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8Wa&&YTB  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GN7\p)  
nEndPos = " + nFileLength); >N&C-6W  
// fileSplitterFetch[nPos.length-1].start(); Tb2Tb2C  
\Y EV 5  
.7BB*!CP  
//等待子线程结束 OG M9e!  
//int count = 0; 1z4s1 Y  
//是否结束while循环 |k # ~  
boolean breakWhile = false; qtx5N)J6  
z%F68 f73  
[i8,rOa7  
while(!bStop) _n[4+S*v(  
{ M"E ]r=1  
write_nPos(); *jBn ^  
Utility.sleep(500); BUuU#e5  
breakWhile = true; c|kQ3(  
!A.Kb74  
@IB+@RmL  
for(int i=0;i<nStartPos.length;i++) Esc*+}ck  
{ 6Y#V;/gK!5  
if(!fileSplitterFetch.bDownOver) #4WA2EW  
{ 6l{=[\.Xa  
breakWhile = false; D92#&,KD  
break; <2\4eusk  
} +2}aCoL\  
}  N+<`Er  
if(breakWhile) Qx_K)  
break; d/Sx+1 "{T  
SqiLp!Y`  
J!%cHqR  
//count++; m[@7!.0=  
//if(count>4) [7QIpt+FSo  
// siteStop(); \X'{ ee  
} F-^#EkEGe  
7R$]BY=  
?c vXuxCm  
System.err.println("文件下载结束!"); \Z +O9T%  
} %cDTy]ILu  
catch(Exception e){e.printStackTrace ();} )/'y'd<r  
} /r4QDwu  
#-QQ_  
_;A?w8z  
//获得文件长度 =4;GIiF@  
public long getFileSize() lC/4CPKtV  
{ )xJo/{?  
int nFileLength = -1; uW.)(l  
try{ Eua\N<!aai  
URL url = new URL(siteInfoBean.getSSiteURL()); }tH$/-qnJE  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lgxG:zAC  
httpConnection.setRequestProperty("User-Agent","NetFox"); FyXz(l:  
</K"\EU  
`_IgH  
int responseCode=httpConnection.getResponseCode(); Ha~g8R&  
if(responseCode>=400) +["t@Q4IQ  
{ N Fc@Kz<H  
processErrorCode(responseCode); ar0y8>]3  
return -2; //-2 represent access is error F5CV<-jB  
} zh hH A9  
xDf<@  
@wWro?s'p  
String sHeader; yDt3)fP#  
!MOgM  
ZMSP8(V  
for(int i=1;;i++) -U6" Ce  
{ JRMe( ,u  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oGzZ.K3 A  
//Utility.log(in.readLine()); FFTh}>>  
sHeader=httpConnection.getHeaderFieldKey(i); *siN#,5  
if(sHeader!=null) 0|0<[:(hc  
{ 0Ywqv)gg  
if(sHeader.equals("Content-Length")) 3pSkk  
{ 2 {lo  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J%?'Q{  
break; %ZF6%m0S  
} c}nXMA^^  
} giy4<  
else JrF\7*rh9  
break; =K<8X!xUW  
} 8ODrW!o  
} t]Ey~-Rx  
catch(IOException e){e.printStackTrace ();} \Rc7$bS2H  
catch(Exception e){e.printStackTrace ();} b|i94y(  
* \@u,[,  
^L&hwXAO:  
Utility.log(nFileLength); [.}-nAN  
LbGyD;#_  
+jcg[|-' /  
return nFileLength; Ybr&z7# 2  
} Y'NQt?h  
sR`WV6!9  
LTsG  
//保存下载信息(文件指针位置) pKrol]cth8  
private void write_nPos() 9/LI[{  
{ h9)QQPP  
try{ a7#J af  
output = new DataOutputStream(new FileOutputStream(tmpFile)); &e\A v.n@-  
output.writeInt(nStartPos.length); $ctY#:;pV{  
for(int i=0;i<nStartPos.length;i++) Ku{DdiTg>  
{ p]*BeiT#n%  
// output.writeLong(nPos); D.2HM  
output.writeLong(fileSplitterFetch.nStartPos); B]K@'#  
output.writeLong(fileSplitterFetch.nEndPos); xF*C0B;QL  
} $x&\9CRM  
output.close(); \2!v~&S  
} * %p6+D-C  
catch(IOException e){e.printStackTrace ();} Zy2@1-z6  
catch(Exception e){e.printStackTrace ();} ,Yg<Z1  
} !$'s?rnh  
fDmGgD?  
T,h,)|:I^  
//读取保存的下载信息(文件指针位置) $wa )e  
private void read_nPos() ?@ ei_<A{  
{ * pN,@ZV$  
try{ i)V-q9\  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o6^^hc\  
int nCount = input.readInt(); fL7ym,?  
nStartPos = new long[nCount]; Hh=D:kE  
nEndPos = new long[nCount]; `F:PWG`  
for(int i=0;i<nStartPos.length;i++) hia_CuY#  
{ wVD-}n1"  
nStartPos = input.readLong(); D/_=rAl1  
nEndPos = input.readLong(); ``o:N`  
} 6Cut[*lj^  
input.close(); 6KmF 9  
} .$>?2|gRv  
catch(IOException e){e.printStackTrace ();} rt5UT~  
catch(Exception e){e.printStackTrace ();} MjMPbGUX{  
} jyPY]r  
_s./^B_w!  
{9KG06%+  
private void processErrorCode(int nErrorCode) xUE9%qO  
{ 7~[1%`  
System.err.println("Error Code : " + nErrorCode); 0(VQwGC[  
} T`46\KkN  
uY;-x~Z  
X%!#Ic]Q  
//停止文件下载 Y418k  
public void siteStop() 2s,wC!',  
{ ;p%a!Im_ <  
bStop = true; j'i-XIs  
for(int i=0;i<nStartPos.length;i++) Fs7/3  
fileSplitterFetch.splitterStop(); v4sc  
@Nb&f<+gi  
fL4F ~@`9l  
} krm&.J  
} Nko;I?Fn  
//负责部分文件的抓取 v`B7[B4K3  
**FileSplitterFetch.java 6Gjr8  
*/ aX6.XHWbDf  
package NetFox; VA_\Z  
m*h d%1D  
%(b`i C9  
import java.io.*; =vBxwa^  
import java.net.*; r'fNQJ >  
 L's_lC  
C\UD0r'p?  
public class FileSplitterFetch extends Thread { c]O3pcU  
LjjE(Yrv{  
uYiM~^ 0  
String sURL; //File URL f+Nq?GvwBQ  
long nStartPos; //File Snippet Start Position 68R[Lc9q5  
long nEndPos; //File Snippet End Position oQ@X}6B%S  
int nThreadID; //Thread's ID ]t]s/;9]K  
boolean bDownOver = false; //Downing is over @jg*L2L6  
boolean bStop = false; //Stop identical nn$,|/  
FileAccessI fileAccessI = null; //File Access interface |/zE(ePc{  
Zr'VA,v  
LOi5 ^Um|  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j&) +qTV  
{ +](^gaDw<L  
this.sURL = sURL; R@t?!`f!+  
this.nStartPos = nStart; 2 5h.u>6@{  
this.nEndPos = nEnd; u!mUUFl  
nThreadID = id; Ph2jj,K  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #sy)-xM  
} Ra[{K@  
95>(NwST4  
5YMjvhr?W  
public void run() zCj]mH`es'  
{ ZffK];D  
while(nStartPos < nEndPos && !bStop) %O>ehIerD  
{ _!H{\kU  
U aj8}7v  
Y<%$;fx$Sx  
try{ rgdDkWLXC  
URL url = new URL(sURL); !.H< dQS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0RN]_z$;H  
httpConnection.setRequestProperty("User-Agent","NetFox"); =K~<& l8  
String sProperty = "bytes="+nStartPos+"-"; ^tIs57!  
httpConnection.setRequestProperty("RANGE",sProperty); ko*Ir@SDv  
Utility.log(sProperty); y[oc^Zuo  
".onev^(  
4!,x3H'  
InputStream input = httpConnection.getInputStream(); ihBlP\C  
//logResponseHead(httpConnection); IM|VGT0  
w4<1*u@${  
b;`gxXeL  
byte[] b = new byte[1024]; u.x>::i&  
int nRead; 3qE2mYK  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fI;6!M#  
{ ,1EyT>  
nStartPos += fileAccessI.write(b,0,nRead); puA~}6C  
//if(nThreadID == 1) 8- 3]Bm!  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q+5g+9  
} @~hiL(IR'  
C:xg M'~+  
xDG8C39qrs  
Utility.log("Thread " + nThreadID + " is over!"); pca `nN!  
bDownOver = true; &eKnLGKD  
//nPos = fileAccessI.write (b,0,nRead); vmm#UjwF3  
} A}?n.MAX>  
catch(Exception e){e.printStackTrace ();} O@6iG  
} #S)+eH  
} NK;%c-r0v7  
'`&gSL.1a@  
A^nB!veh  
//打印回应的头信息 FJomUVR.  
public void logResponseHead(HttpURLConnection con) X|fl_4NC>  
{ \/J>I1J  
for(int i=1;;i++) Fy37I/#)r&  
{ q">lP (t  
String header=con.getHeaderFieldKey(i); 1`J-|eH=Q  
if(header!=null) )0 UVT[7  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AP5[}$TT  
Utility.log(header+" : "+con.getHeaderField(header)); 0F> ils  
else 5&Al  
break; $_IvzbOh  
} o|O730"2F  
} y:u7*%"  
>uT,Z,7O  
>?>@&A/  
public void splitterStop() :@#9P,"  
{ -d5b,leC^  
bStop = true; l*~O;do  
} [Z9 lxZ|  
n]:Xmi8p  
UtPFkase  
} Y1fcp_]m  
3kfrOf.4h  
z,dh?%H>X  
/* )tYu3*'  
**FileAccess.java !*Ex}K99  
*//文件访问(定位,写) 9/2VU< K  
package NetFox; @9#l3  
import java.io.*; )+ifVv50  
c"D%c(:4|  
X.}i9a 6  
public class FileAccessI implements Serializable{ X<G"Ga L  
Nl/^ga  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `%S 35x9  
RandomAccessFile oSavedFile; 0C!f/EZK  
long nPos; pGZiADT  
y buKwZFC  
4^uQB(}Z  
public FileAccessI() throws IOException x -;tV=E}  
{ 0b=1Ce+0q  
this("",0); ozaM!ee\z  
} <c'0-=  
RW"QUT  
709/'#- ^  
public FileAccessI(String sName,long nPos) throws IOException m&S *S_c  
{ 9-:\ NH^;  
oSavedFile = new RandomAccessFile(sName,"rw"); xhcFZTj/(  
this.nPos = nPos; LH}]& >F  
oSavedFile.seek(nPos); }ejZk bP  
} (8"advc6  
a4d7;~tZ  
f4'WT  
public synchronized int write(byte[] b,int nStart,int nLen) ehTrjb3k  
{ I<+EXH%1,  
int n = -1; w'uB&z4'  
try{ sdp3geBYo  
oSavedFile.write(b,nStart,nLen); z] +&kNm  
n = nLen; i}Q"'?  
} jK^Q5iD  
catch(IOException e) uH{oJSrK  
{ i0}f@pCB?X  
e.printStackTrace (); 8 $qj&2 N  
} HPryq )z  
_DouVv>  
B\54eTn  
return n; TJ_Wze-lQ  
} MCO2(E-  
}3O 0nab  
]\Z8MxFD  
} jK-b#h.gL  
3N[Rrxe2  
a%nf )-}|  
/* c/DK31K  
**SiteInfoBean.java (S~kNbIa  
*/ FUVp}>#U  
package NetFox; i 558&:  
< k?pnBI_  
AqiH1LAE  
public class SiteInfoBean { .H@b zm  
~^TH5n  
PrHoN2y5E  
private String sSiteURL; //Site's URL ,njlKkFw^Z  
private String sFilePath; //Saved File's Path Xf#+^cQ  
private String sFileName; //Saved File's Name 2@N9Zk{{J  
private int nSplitter; //Count of Splited Downloading File h! Bg} B~  
W{%X1::q$  
h% eGtd$n  
public SiteInfoBean()  PI.Zd1r  
{//nSplitter的缺省值为5 HLkI?mW<  
//default value of nSplitter is 5 lc8g$Xw3  
this("","","",5); _\.4ofK(  
} h/Yxm2  
j{j5TvsrY  
!r8_'K5R(  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ..kFn!5(g  
{ h,?%,GI  
sSiteURL= sURL; TSD7R  
sFilePath = sPath; Lf)JO|o  
sFileName = sName; Uc,MZV4  
this.nSplitter = nSpiltter; PJ)l{c  
~N%+ZXh&E  
-{}h6r  
} km*Y#`{  
H:|.e)$i  
Fge ["p?GF  
public String getSSiteURL() le' Kp V  
{ 80=LT-%#  
return sSiteURL; 1>uAVPa  
} :c|Om{;  
!Rc %  
U9\\8  
public void setSSiteURL(String value) 74ho=  
{ gW<6dP'v  
sSiteURL = value; nU' qE  
} m_;fj~m  
P-a8S*RRa  
)Q62I\  
public String getSFilePath() !u'xdV+bf  
{ rFGPS%STS  
return sFilePath; D;s%cL`  
} <S=( `D  
'pT13RFD  
EjFn\|VK  
public void setSFilePath(String value) [-VK! 9pQ  
{ tkH]_cH'w  
sFilePath = value; "P0!cY8r  
} >|c?ZqW  
Ka6u*:/  
4#}aLP  
public String getSFileName() Gh/nNwyu<  
{ &TY74 w*  
return sFileName; \i/HHP[%  
} 'YB[4Q /0  
tT!' qL.*  
xVw@pR;  
public void setSFileName(String value) :'B(DzUR  
{ <$yA*  
sFileName = value; Wlxmp['Bh  
} Ufl\ uq3'H  
'iF%mnJ  
p:TE##  
public int getNSplitter() /='0W3+o*L  
{ pHoHngyi&  
return nSplitter; }2@Z{5sh)  
} y%ij)vQY  
-N% V5 TN  
u.|%@  
public void setNSplitter(int nCount) ~CT]&({  
{ U+qyS|i  
nSplitter = nCount; (_|*&au J  
} g=[OH  
} o S=!6h  
QK?V^E  
eM_;rMCr}  
/* j &,Gv@  
**Utility.java kBhjqI*  
*/ 5"@>>"3U  
package NetFox; e,epKtL  
~1D^C |%  
l>K+4  
public class Utility { A[uE#T ^  
)-_^vB  
tu<<pR>  
public Utility() 3!b $R?kZ  
{ w.w{L=p:<"  
L4Zt4Yuw  
,eBC]4)B6  
} \KnRQtlI  
B;ek a[xU  
//线程睡眠 )][U6e  
public static void sleep(int nSecond) : c~SH/qS  
{ 5aizWz  
try{ '";#v.!  
Thread.sleep(nSecond); D#L(ZlD4  
} M i& ;1!bg  
catch(Exception e) ^T!Zz"/:  
{ R|8vdZ%@  
e.printStackTrace (); ,)Q-o2(C  
} ekvs3a^  
} uVUU1@  
x6`mv8~9Db  
//日志 WVRIq'  
public static void log(String sMsg) llP V{  
{ gSwV:hm  
System.err.println(sMsg); i"}z9Ae~.  
} VkFh(Br<{  
6ieul@?*u*  
Q4m> 3I  
public static void log(int sMsg) 3<&:av3  
{ ~D9Cu>d9  
System.err.println(sMsg); U0_)J1Yp  
} 9s^$tgH  
} $_"u2"p  
U`q keNd  
qUd7O](b=?  
/* GK}52,NM  
**TestMethod.java LZn'+{\`  
*/ =@Oo3*>  
package NetFox; G1 "QX  
ByY2KJ7  
xn3 _ ED  
public class TestMethod { m`-);y  
Ma|4nLC}  
R xMsP;be  
public TestMethod() ~o!- [  
{ ///xx/weblogic60b2_win.exe X(ph$,[  
try{ \Osu1]Jn>  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,,{;G'R|  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?$6H',u  
SiteFileFetch fileFetch = new SiteFileFetch(bean); i\6CE|  
fileFetch.start(); >}V?GK36  
} !"F;wg$  
catch(Exception e){e.printStackTrace ();} @PvO;]]%  
:/T\E\Qr  
BTkx}KK  
} b)I-do+  
|/gt;H~:  
cX-M9Cz  
public static void main(String[] args) qi4P(s-i  
{ Dx-P]j)4x  
new TestMethod(); ">bhxXeiN  
} ln82pQD2Y~  
} Q~ U\f$N  
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