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http断点续传简单实现(java)

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/* i|2$8G3  
**SiteFileFetch.java $fArk36O#  
*/ q G ;-o)h  
package NetFox; \v`#|lT$  
import java.io.*; ^/KfH &E  
import java.net.*; `\FI7s3b  
.A<sr  
+802`eax  
public class SiteFileFetch extends Thread { LZWS^77  
|Mg }2!/L  
6zYaA  
SiteInfoBean siteInfoBean = null; //文件信息Bean O.:I,D&]  
long[] nStartPos; //开始位置 D?u`  
long[] nEndPos; //结束位置 SfI*bJo>V  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 cqQRU  
long nFileLength; //文件长度 GfsBQY/  
boolean bFirst = true; //是否第一次取文件 *m_93J  
boolean bStop = false; //停止标志 dXP6"V@iI  
File tmpFile; //文件下载的临时信息 9={N4}<  
DataOutputStream output; //输出到文件的输出流 >iy^$bqF  
g5R,% 6  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) #4y,a_)  
public SiteFileFetch(SiteInfoBean bean) throws IOException A o3HX  
{ i>Iee^_(  
siteInfoBean = bean; 7Jx%JgF  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); )*[ ""&  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); AUAI3K?  
if(tmpFile.exists ()) d7~j^v)=^  
{ 9y+[o  
bFirst = false; NiTJ}1 l  
read_nPos(); )1_(>|@oi  
} :GL7J6  
else GoeIjuELR  
{ q:yO92Ow  
nStartPos = new long[bean.getNSplitter()]; 1p CkWe  
nEndPos = new long[bean.getNSplitter()]; %8Yyj{^!(  
} V<-htV  
* -z4<LAa  
94z8B;+ H]  
^gm>!-Gx  
} A7'bNd6f9  
5^F]tRz-  
uu3M{*}  
public void run() i`~~+6`J  
{ + zDc  
//获得文件长度 Yq0# #__  
//分割文件 X8b#[40:  
//实例FileSplitterFetch !QTPWA  
//启动FileSplitterFetch线程 $I(}r3r  
//等待子线程返回 ;C_ >  
try{ 1 ;Ju]  
if(bFirst) G;2[  
{ ?>)yKa#U  
nFileLength = getFileSize(); /| f[us-w  
if(nFileLength == -1) uo 4xnzc  
{ ?waebuj>  
System.err.println("File Length is not known!"); ]^ !}*  
} U?EG6t  
else if(nFileLength == -2) (fd[P|G_]  
{  QT_^M1%  
System.err.println("File is not access!"); ?360SQ<  
} w -dI<s  
else [|z'"Gk{  
{ WgZ@N  
for(int i=0;i<nStartPos.length;i++) \P@S"QO  
{ pE(sV{PD  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); _Y7:!-n}   
} x:C@)CAr  
for(int i=0;i<nEndPos.length-1;i++) !OQuEJR  
{ Loc8eToZ  
nEndPos = nStartPos[i+1]; +I.v!P!^  
} @SQceQfB  
nEndPos[nEndPos.length-1] = nFileLength; R_9 o!s TZ  
} =SL^>HS.fo  
} LT& /0  
JilKZQmk  
Re\o v x9  
//启动子线程 }6@%((9E 2  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hG~Uz   
for(int i=0;i<nStartPos.length;i++) +Wd L  
{ (-'PD_|  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D9G0k[D,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 85 Dm8~  
nStartPos,nEndPos,i); 'F<Sf:?.p  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5E.vje{U;  
fileSplitterFetch.start(); U 5clQiow  
} No~ 6s.H  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =ty2_6&>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X$PS(_M  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;Lqm#]C  
nEndPos = " + nFileLength); _]_LF[  
// fileSplitterFetch[nPos.length-1].start(); 'Dq"e$JM<  
O E]~@eU  
ME,duY/>Q  
//等待子线程结束 8ur_/h7  
//int count = 0; uAQg"j  
//是否结束while循环 3m~U(yho  
boolean breakWhile = false; (Y>U6  
X; 5S  
vS2(Q0+TZi  
while(!bStop) r=|vad$  
{ lkyJ;}_**  
write_nPos(); Y& m<lnB  
Utility.sleep(500); fW[_+r]  
breakWhile = true; ?Cc$]  
.;j"+Ef   
y "<JE<X  
for(int i=0;i<nStartPos.length;i++) }Uq/kei^P  
{ #W.bZ]&WA  
if(!fileSplitterFetch.bDownOver) ;wp W2%&  
{ R<t&F\>  
breakWhile = false; )biX8yq hR  
break; |B,dEx/uU  
} WE7>?H*Ro  
} JfR kp  
if(breakWhile) Zq9>VqGe  
break; 9/^d~ ZO  
we @Yw6<  
y.%i  
//count++; cx<h_  
//if(count>4) vDWr|M%``l  
// siteStop(); EyzY2>"^  
} x9 TuweG  
cFe V?a  
YqkA&qL]#;  
System.err.println("文件下载结束!"); @RQ+JYQi  
} .!9Vt#  
catch(Exception e){e.printStackTrace ();} "hz>{oe  
} i^~sn `o  
5N Fq7&rJ6  
e-1;dX HL  
//获得文件长度 n2H&t>N  
public long getFileSize() t% <pbZO  
{ 5BZ+b_A>VV  
int nFileLength = -1; _8Pmv$   
try{ yFIl^Ck%  
URL url = new URL(siteInfoBean.getSSiteURL()); JHHb|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EC0zH#N  
httpConnection.setRequestProperty("User-Agent","NetFox"); n&3iz05}  
e3G7K8  
.`b4h"g:  
int responseCode=httpConnection.getResponseCode(); q=J9L Q  
if(responseCode>=400) T %$2k>  
{ @^B S#  
processErrorCode(responseCode); $HP/c Ku  
return -2; //-2 represent access is error 5^bh.uF  
} <d3PDO@w/  
4,o %e,z  
`e4o1 *  
String sHeader; !>?4[|?n<  
JvT %R`i  
N;e}dwh&  
for(int i=1;;i++) !^n1  
{ xq8}6Q  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U;^CU!a  
//Utility.log(in.readLine()); x;<oaT$X  
sHeader=httpConnection.getHeaderFieldKey(i); <|ka{=T  
if(sHeader!=null) I3V{"Nx6  
{ c8 H9_6  
if(sHeader.equals("Content-Length")) 2(@LRl>:  
{ nYmf(DV  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mrw]yu;2<n  
break; 8') .o hD  
} };4pZceV  
} \H},ou U  
else B4PW4>GF  
break; g/fp45s  
} ly9x1`?$  
} m T>b ;  
catch(IOException e){e.printStackTrace ();} #JHy[!4  
catch(Exception e){e.printStackTrace ();} (jD'+ "?  
 zZS>+O  
J r=REa0  
Utility.log(nFileLength); oHv{Y  
<L[T'ZE+  
liBAJx  
return nFileLength; HQ ELK  
} BT y]!%r'  
v4nv Z6  
0(Yh~{   
//保存下载信息(文件指针位置) Nv}U/$$S  
private void write_nPos() )*q7pO\cty  
{ V'Sd[*  
try{ T)$ 6H}[c  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z1XUYe62  
output.writeInt(nStartPos.length); R!:eYoQ  
for(int i=0;i<nStartPos.length;i++) LC~CPV'F  
{ tuL\7 (R  
// output.writeLong(nPos); G~b`O20N  
output.writeLong(fileSplitterFetch.nStartPos); bW,BhUb,|  
output.writeLong(fileSplitterFetch.nEndPos); E#IiyZ  
} ?uNTUU,  
output.close(); 4i ~eTb  
} xg*\j)_}  
catch(IOException e){e.printStackTrace ();} ~ z-?rW  
catch(Exception e){e.printStackTrace ();} v Ie=wf~D`  
} __oY:d(~  
-N /8Ho  
}.fZy&_  
//读取保存的下载信息(文件指针位置) "t3uW6&  
private void read_nPos() N2+mN0k;  
{ D;1 6}D  
try{ ,)B~cic'u  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SXT@& @E  
int nCount = input.readInt(); UBUB/N Y  
nStartPos = new long[nCount]; (Von;U  
nEndPos = new long[nCount]; W>aQ tT  
for(int i=0;i<nStartPos.length;i++) wsdB; 6%$  
{ e>ZbZy?  
nStartPos = input.readLong(); \FY/eQ*07  
nEndPos = input.readLong(); yhw:xg_;Kz  
} \UkNE5  
input.close(); k'WS"<-  
} 6Y92&  
catch(IOException e){e.printStackTrace ();} |ec(z  
catch(Exception e){e.printStackTrace ();} k8Su/U  
} JO<gN= [  
mM\!4Yi`7  
u`L!za7fi  
private void processErrorCode(int nErrorCode) |g: '')>[  
{ &UJ Ty'  
System.err.println("Error Code : " + nErrorCode); &k%wOz1vM  
} mTrI""Jsu;  
.>AFf9P  
(IO \+  
//停止文件下载 L XTipWKz  
public void siteStop() ZYl-p]\*y  
{ 6I5[^fv45G  
bStop = true; )Ta]6  
for(int i=0;i<nStartPos.length;i++) ^-c si   
fileSplitterFetch.splitterStop(); /:*R -VdF  
W_e-7=6  
"W,"qFx  
} @vQ;>4i.  
} wt_?B_nR  
//负责部分文件的抓取 nkr,  
**FileSplitterFetch.java 1A)wbH)  
*/ kcma/d  
package NetFox; >ji}j~cH  
6bA~mC^&  
b6?Xo/lJ.  
import java.io.*; eJVOVPg<,  
import java.net.*; Z7KB?1{G  
SoM ]2^  
SzgY2+Qq  
public class FileSplitterFetch extends Thread { rH} Dt@  
3LmBV\["  
n'x`oI)-  
String sURL; //File URL XSHwE)m  
long nStartPos; //File Snippet Start Position lhIr]'?l  
long nEndPos; //File Snippet End Position c!(~BH3p  
int nThreadID; //Thread's ID {8>_,z^P)  
boolean bDownOver = false; //Downing is over U# FJ8CD&u  
boolean bStop = false; //Stop identical LzEE]i  
FileAccessI fileAccessI = null; //File Access interface fO^EMy\  
.eDxIWW+ft  
mXN1b!  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6"rFfdns  
{ yo Q?lh  
this.sURL = sURL; wZ\e3H z  
this.nStartPos = nStart; n_!]B_Vd$  
this.nEndPos = nEnd; }ii]c Y  
nThreadID = id; [w#x5Xsn  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &s6(3k  
} :+Z>nHe  
=Y=^]ayO/  
46.q a nh  
public void run() [<3Q$*Ew  
{ EiIFVP   
while(nStartPos < nEndPos && !bStop) %8`1Li6g  
{ 0F;(_2V-  
t6,M  
m?kIa!GM=  
try{ 7Hr4yh[j&  
URL url = new URL(sURL); J z:W-o  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gYH:EuY,  
httpConnection.setRequestProperty("User-Agent","NetFox"); vI:bl~  
String sProperty = "bytes="+nStartPos+"-"; ,{mf+ 3&$,  
httpConnection.setRequestProperty("RANGE",sProperty); 5sV/N] !  
Utility.log(sProperty); ][>M<J  
&|&YRHv  
?`[ uh%  
InputStream input = httpConnection.getInputStream(); o`y*yucHI  
//logResponseHead(httpConnection); >FMT#x t  
TF}4X;3Dsy  
5)SZd)  
byte[] b = new byte[1024]; '\E*W!R.]  
int nRead; 2YP"nj#  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @T~#Gwv  
{ WY. \<$7  
nStartPos += fileAccessI.write(b,0,nRead); l.NkS   
//if(nThreadID == 1) |2t7mat  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nD?M;XN  
} $0`$)(Y  
X-2S*L'  
*IO;`k q,;  
Utility.log("Thread " + nThreadID + " is over!"); k @/SeE  
bDownOver = true; Wp9 2sm+  
//nPos = fileAccessI.write (b,0,nRead); .5Z@5g`  
} 3vGaT4TDx  
catch(Exception e){e.printStackTrace ();} da86Jj=k  
} EA@$^e[  
} %H 6ZfEO  
`))J8j"  
KlX |PQ  
//打印回应的头信息 u>i+R"hi"  
public void logResponseHead(HttpURLConnection con) H|Fqc=qp  
{ u4*]jt;H  
for(int i=1;;i++) ]2s Zu7  
{ jiB>.te  
String header=con.getHeaderFieldKey(i); {HJ`%xN|  
if(header!=null) 3b[[2x_UU  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {pJ@I=q  
Utility.log(header+" : "+con.getHeaderField(header)); Y| N vBr  
else I9j+x ])  
break; fM[fS?W  
} kKk |@  
} &u`rE""  
nR|LV'(  
'hHX"\|RA  
public void splitterStop() 2Q_{2(nQb  
{ GHsdLe=t0#  
bStop = true; !vo'8r?&  
} ][K8\  
&8YI)G%  
U@t?jTMBkO  
} VEYKrZA  
uB&I56  
SIBIh-L  
/* BHBT=,sI  
**FileAccess.java lo;9sTUHT  
*//文件访问(定位,写) .$s|T  
package NetFox; nF y7gA|  
import java.io.*; xbH!:R;  
$8ww]}K  
iqKfMoy5  
public class FileAccessI implements Serializable{ Wes "t}[25  
ZYt"=\_  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DBrzw+;e3  
RandomAccessFile oSavedFile; &l}xBQAL  
long nPos; S$_Ts1Ge6  
-clg 'Aa;.  
N*)8L[7_;  
public FileAccessI() throws IOException \]:NOmI^'  
{ ghd[G}  
this("",0); j tkPi)QR  
} K.L+; nQ  
f%%En5e +  
Q_h+r! b  
public FileAccessI(String sName,long nPos) throws IOException ( =/L#Yg_  
{ ScmzbDu  
oSavedFile = new RandomAccessFile(sName,"rw"); yW,#&>]# |  
this.nPos = nPos; gl{P LLe[}  
oSavedFile.seek(nPos); +q?0A^C>  
} P##(V!YR  
2o3k=hKS  
~ilBw:L-3  
public synchronized int write(byte[] b,int nStart,int nLen) .?)oiPW#  
{ <+JFal  
int n = -1; 0J,d9a [1  
try{  G/;aZ  
oSavedFile.write(b,nStart,nLen); Jt^JE{m9%  
n = nLen; .xQ'^P_q  
} M@ZpgAfq  
catch(IOException e) <T~fh>a  
{ RpXGgw  
e.printStackTrace (); &XTd[_VW!  
} EC\:uK  
gK_[3FiKt  
b6M)qt9R  
return n; mztq7[&-  
} 3\~fe/z'I  
>bP7}T  
a_MnQ@  
} QF6JZQh<  
"JGig!9  
+GtGyp  
/* ^7<mlr  
**SiteInfoBean.java &y wY?ox  
*/ gM[ J'DMW  
package NetFox; g 5N<B+?!i  
(w  
,colGth 54  
public class SiteInfoBean { KvOI)"0(  
f;dU72]q+  
H LGy"P  
private String sSiteURL; //Site's URL P[K T  
private String sFilePath; //Saved File's Path *J5euA5=  
private String sFileName; //Saved File's Name "r3s'\  
private int nSplitter; //Count of Splited Downloading File 7n]%`Yb  
iz5wUyeg  
m|gd9m $,?  
public SiteInfoBean() RLX^'g+P  
{//nSplitter的缺省值为5 ;XuE Mq,Di  
//default value of nSplitter is 5 n,LKkOG  
this("","","",5); ]KT,s].  
} [:'?}p  
\`5u@Nzx  
J~`%Nj5>  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $F$R4?_  
{ UeeV+xU  
sSiteURL= sURL; }r<^]Q*&p  
sFilePath = sPath; [,X,2  
sFileName = sName; `;GGuJb \  
this.nSplitter = nSpiltter; dR{ V,H7N  
6MQ:C'8T&=  
QP0X8%+p  
} HaUo+,=  
5ml}TSMu'  
n:] 1^wX#  
public String getSSiteURL() =x]dP.  
{ rs+37   
return sSiteURL; 1D DOUV  
} 8Y'"=!3  
{-qTU6  
k= 1+mG  
public void setSSiteURL(String value) L#b Q`t  
{ ay[*b_f  
sSiteURL = value; M&-/ &>n!  
} "A3xX&9-q  
l_EI7mJ  
A2S9h,t  
public String getSFilePath() S*:w\nXP~  
{ vH8%a8V  
return sFilePath; ]iX$p~riH  
} Rj= Om  
_ @76eZd  
j)*nE./3  
public void setSFilePath(String value) 5nb6k,+E  
{ bd}SB-D  
sFilePath = value; pSUp"wch  
} ZK*aVYnu  
y$NG..S  
4tTJE<y  
public String getSFileName() z|H>jit+  
{ N Q=YTRU  
return sFileName; Dw,f~D$+ic  
} k JFHUR  
c>.Xc[H  
Lcm!e  
public void setSFileName(String value) BT0hx!Ti  
{ Gjr2]t;E  
sFileName = value; !~v>&bCG>9  
} (P8oXb+%  
&i RX-)^u  
r U5'hK  
public int getNSplitter() \ } f*   
{ xc?<:h"  
return nSplitter; rfpxE>_|G  
} E 3.s8}}  
2_v>8B  
:"]ei@  
public void setNSplitter(int nCount) LcF3P 4  
{ :LG%8Z{R  
nSplitter = nCount; A4h/oMis  
} h65j,v6B  
} rg.if"o  
H)tDfk sq\  
F{tSfKy2  
/* L~~Yh{<  
**Utility.java cw{[B%vw  
*/ Y?cw9uYB  
package NetFox; | &vuK9q  
o5R40["  
U)8]pUI+/P  
public class Utility { <X*8Xzmv  
37Y]sJrs$  
_#B/# ^a  
public Utility() eH{ 9w8~  
{ 6Tnzg`0I  
]9Hy "#Fz  
Nig-D>OS  
} F)Lbr>H?I  
 sd%~pY}  
//线程睡眠 7/L7L5h<  
public static void sleep(int nSecond) *_wBV M=2  
{ :_*Q IyW  
try{ w3D_ c~  
Thread.sleep(nSecond); pkx>6(Y  
} vKf=t&gqr  
catch(Exception e) g=Di2j{A  
{ -f=hL7NW  
e.printStackTrace (); $(U|JR@  
} 9j`-fs@:  
} mZyTo/\0  
wQT'~'kL  
//日志 6* 7&X#gG  
public static void log(String sMsg) _L":Wux  
{ bSfQH4F  
System.err.println(sMsg); HenJlo  
} ~@lNBF  
F04Etf 2k  
R8l9i2  
public static void log(int sMsg) xJCpWU3wM  
{ )w-?|2-w5  
System.err.println(sMsg); CCV~nf  
} Rd)QVEk>SD  
} UZ#2*PH2E  
d/1XL[&  
s9iM hCu|  
/* \BL9}5y  
**TestMethod.java @#apOoVW>  
*/ Sls> OIc  
package NetFox; /Ny&;Y  
5oS\uX|  
o6 /?WR9  
public class TestMethod { Cmj)CJ-  
q@:&^CS  
"|if<hx+  
public TestMethod() 3nO|A: t  
{ ///xx/weblogic60b2_win.exe n>WS@b/o  
try{ XJ;/ kR  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 00i9yC8@6  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N2>JG]G  
SiteFileFetch fileFetch = new SiteFileFetch(bean); bb{+  
fileFetch.start(); 8{C3ijR  
} Tx*m p+q  
catch(Exception e){e.printStackTrace ();} fvD wg  
*M:Bhw  
DN+`Q{KS  
} Ju<D7  
9!LAAE`  
jJ|;Nwm<[  
public static void main(String[] args) ^;a[v^&9  
{ y.zQ `  
new TestMethod(); J}JnJV8|G  
} c,@6MeKHq  
} v,;?+Ck  
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