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http断点续传简单实现(java)

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/* 5L42'gJ  
**SiteFileFetch.java 2xni! *T+  
*/ tJUMLn?  
package NetFox; ZJP.-`U  
import java.io.*;  []1VD#  
import java.net.*; r1}OlVbK  
-J:](p  
xHJ+!   
public class SiteFileFetch extends Thread { d}>Nl$  
HOsq _)K  
:?RooJ~#  
SiteInfoBean siteInfoBean = null; //文件信息Bean d{9rEB?  
long[] nStartPos; //开始位置 R{8nR0 0|1  
long[] nEndPos; //结束位置 s+yBxgQ/  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 WWrD r  
long nFileLength; //文件长度 1#(,Bq4  
boolean bFirst = true; //是否第一次取文件 %ia/i :  
boolean bStop = false; //停止标志 < hZA$.W3  
File tmpFile; //文件下载的临时信息 M_T$\z;,  
DataOutputStream output; //输出到文件的输出流  >pv~$  
Y_p   
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 0"#tK4  
public SiteFileFetch(SiteInfoBean bean) throws IOException  n1y#gC  
{ e|):%6#  
siteInfoBean = bean; Z #w1,n88  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); cGsP0LkHC  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); iq5h[  
if(tmpFile.exists ()) m3F.-KPO  
{ feIAgd},  
bFirst = false; !g=,O6  
read_nPos(); b\U Q6 V  
} ^-~.L: }q  
else VXn]*Mo  
{ x\3 ` W  
nStartPos = new long[bean.getNSplitter()]; &I:X[=;g  
nEndPos = new long[bean.getNSplitter()]; {KeHqM}e  
} 0Ny0#;P  
15iCJ p  
{8@?9Z9R{  
Lt@4F   
} /A_</GYs  
W E|L{  
.DHZs#R  
public void run() gLl?e8[F  
{ z;#}u C  
//获得文件长度 z ]o&^Q  
//分割文件 C(?>l.QGw  
//实例FileSplitterFetch O5Yk=-_m  
//启动FileSplitterFetch线程 u-OwL1S+  
//等待子线程返回 L@CN0ezQs  
try{ U6jlv3  
if(bFirst) o$d; Y2K  
{ "SLN8x49(  
nFileLength = getFileSize(); cp0>Euco=  
if(nFileLength == -1) ?tqTG2!(  
{ XXuU@G6Z7$  
System.err.println("File Length is not known!"); 1_7x'5GdA  
} 75!IzJG  
else if(nFileLength == -2) # Sb1oLC  
{ %L/Wc,My  
System.err.println("File is not access!"); bxkp9o  
} 4)JrOe&k  
else "uTzmm$  
{ 6by5VESx  
for(int i=0;i<nStartPos.length;i++) TQE3/IL  
{ mEz&:A  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); hrU.QF8  
} i&mu=J[  
for(int i=0;i<nEndPos.length-1;i++) W>wE8? _,  
{ YXrTm[P  
nEndPos = nStartPos[i+1]; m[ay  
} `u%//m_(  
nEndPos[nEndPos.length-1] = nFileLength; ReZ|q5*  
} e_k1pox]l  
} B wtD!de$  
f]T#q@|lE  
9y.C])(2  
//启动子线程 q6H90Zb  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |5e/.T$  
for(int i=0;i<nStartPos.length;i++) HQ/PHUg2  
{ ZzzQXfA#  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3|9) A+,#  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1ReO.Dd`R  
nStartPos,nEndPos,i); f IQ$a >  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mOGcv_L  
fileSplitterFetch.start(); _)2N Fq  
} {Swou>X4  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -a&wOn-W  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e3) rF5pp  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~}8 3\LI}  
nEndPos = " + nFileLength); r6Pi ZgR  
// fileSplitterFetch[nPos.length-1].start(); kRSu6r9  
$qg5m,1?  
e)!X9><J  
//等待子线程结束 p7zHP  
//int count = 0; 1tQZyHc42;  
//是否结束while循环 si3i#l&.b_  
boolean breakWhile = false; ',m,wp`  
;[g v-H  
1MfRF v  
while(!bStop) |],{kUIXO  
{ |I)xK@7  
write_nPos(); }-: d*YtK  
Utility.sleep(500); <C# s0UX  
breakWhile = true; YA{Kgc^  
2[j|:Ng7  
xhg{!w  
for(int i=0;i<nStartPos.length;i++) wnt^WW=a[  
{ ;bP7|  
if(!fileSplitterFetch.bDownOver) -}4H'%Z(i  
{ PJO;[: .I  
breakWhile = false; j1**Ch/  
break; I`Rxijz  
} u+8_et5T  
} P4R.~J ;8  
if(breakWhile) +n2x@ 0op  
break; d@8_?G}  
3Y=T8Gi#  
47$JN}qI0  
//count++; O!Mm~@MoA  
//if(count>4) 7F}I.,<W  
// siteStop(); -W+dsZ Sv8  
} 0A5xG&  
(z^2LaM `8  
; h/Y9uYn  
System.err.println("文件下载结束!"); 1REq.%/=  
} A{&Etu(K  
catch(Exception e){e.printStackTrace ();} e|+uLbN&;c  
} V!]e#QH;  
G>#L  
t@4X(i0  
//获得文件长度 El"XF?OgpP  
public long getFileSize() = 2My-%i  
{ sI*( MhU  
int nFileLength = -1; :*}tkr4&eh  
try{ wx<5*8zP  
URL url = new URL(siteInfoBean.getSSiteURL()); Ix1ec^?f  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bs_I{bCu?  
httpConnection.setRequestProperty("User-Agent","NetFox"); jUBlIVl]  
[0)iY%^  
:,GsbNKW  
int responseCode=httpConnection.getResponseCode(); QbOm JQ  
if(responseCode>=400) zg8m(=k'  
{ 8&`s wu&  
processErrorCode(responseCode); 8MW|CM4Q  
return -2; //-2 represent access is error 3@6f%Dyj  
} K")-P9I6-f  
m#%5H  
@["Vzg!I6"  
String sHeader; xA&G91|s  
{/#?n["  
I"<~!krt%  
for(int i=1;;i++) BT`/O D@  
{ ?P"ht  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1iF |t5>e  
//Utility.log(in.readLine()); &?zJ|7rh@|  
sHeader=httpConnection.getHeaderFieldKey(i); ;y"E}h  
if(sHeader!=null) XPWK"t0 1  
{ 27,WP-qie  
if(sHeader.equals("Content-Length")) _NqEhf:8  
{ ^f3F~XhY3  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \>,{)j q;  
break; RJBNY;0  
} 3+n&Ya1  
} n:k~\-&WJ  
else ShGR !r<  
break; RQ/X{<lQ)  
} wPqIy}-  
} =;@5Ue J  
catch(IOException e){e.printStackTrace ();} gDAA>U3|$  
catch(Exception e){e.printStackTrace ();} UN,@K9  
O a-Z eCq  
#( X4M{I  
Utility.log(nFileLength); =A=er1~%  
M-|4cd]6  
]9A9q<lZ  
return nFileLength; M[TgNWl/[  
} >rYP}k  
5^P)='0*  
<=jE,6_|  
//保存下载信息(文件指针位置) (h`||48d  
private void write_nPos() PlBT H  
{ skZxR5v3~L  
try{ 8$3Tu "+;  
output = new DataOutputStream(new FileOutputStream(tmpFile)); W@pVP4F0xM  
output.writeInt(nStartPos.length); >`s2s@Mx  
for(int i=0;i<nStartPos.length;i++) Y.Gr(]tk  
{ 4[+n;OI  
// output.writeLong(nPos); #^Sd r-   
output.writeLong(fileSplitterFetch.nStartPos); Fwho.R-.  
output.writeLong(fileSplitterFetch.nEndPos); ?~u"w OH'  
} :K2N7?shA  
output.close(); hc~--[1c:  
} GH^i,88  
catch(IOException e){e.printStackTrace ();} ZJ+q<n_4}  
catch(Exception e){e.printStackTrace ();} n%Nf\z  
} HOu<,9?>Q  
?c=l"\^x  
1 ht4LRFi  
//读取保存的下载信息(文件指针位置) p,ZubR J"  
private void read_nPos() oOQnV(I  
{ #sNa}292"  
try{ #i:p,5~")  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w*Kw#m'U  
int nCount = input.readInt(); ;:"~utL7  
nStartPos = new long[nCount]; IVEvu3  
nEndPos = new long[nCount]; c67O/ B(  
for(int i=0;i<nStartPos.length;i++) Ep?a1&b  
{ `\O[9.B  
nStartPos = input.readLong(); iFga==rw  
nEndPos = input.readLong(); 0g`WRe  
} jd(=? !_  
input.close(); p &XbXg-  
} WY<ip<  
catch(IOException e){e.printStackTrace ();} h2uO+qEsu  
catch(Exception e){e.printStackTrace ();} "$ u"Py  
} uOm fpgO  
YZ/mTQn_D  
N"HN] Y@w  
private void processErrorCode(int nErrorCode) SM0=  
{ HM ^rk  
System.err.println("Error Code : " + nErrorCode); EeL~`$f  
} s g6  
%;ny  
Z>Sv[Ec  
//停止文件下载 sowkxw.^Q  
public void siteStop() z2nDD6N  
{ ){8^l0b  
bStop = true; ~EX/IIa{  
for(int i=0;i<nStartPos.length;i++) nA%-<  
fileSplitterFetch.splitterStop(); 5UjXpS  
C]eb=rw$  
:5C9uW #  
} #gi&pR'$  
} :) mV-(+o  
//负责部分文件的抓取 =Z%&jul  
**FileSplitterFetch.java 2b3x|9o8  
*/ *3. ]  
package NetFox; !U=;e?o  
/z5j.TMs  
6VCw>x  
import java.io.*; D Q~+\  
import java.net.*; IsnC_"f  
iOzw)<  
JnPA;1@/  
public class FileSplitterFetch extends Thread { qmJFXnf  
2nOQ48ha T  
1xcx2L+R  
String sURL; //File URL 0'aZ*ozk  
long nStartPos; //File Snippet Start Position S(/@.gI:f  
long nEndPos; //File Snippet End Position 5E}0 <&  
int nThreadID; //Thread's ID H^'EY:|  
boolean bDownOver = false; //Downing is over Q:@Y/4=  
boolean bStop = false; //Stop identical #YjV3O5<  
FileAccessI fileAccessI = null; //File Access interface 9u"im+=:  
ZLo3 0*  
rpy`Wz/[  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I"Y?vj9]  
{ ?Yz.tg  
this.sURL = sURL; ;jI\MZ~l\  
this.nStartPos = nStart; o$Hc5W([Z  
this.nEndPos = nEnd; zg|yW6l)9  
nThreadID = id; N!Kd VDdT|  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jZ.+b j >  
} {s_0[>  
`p'L3u5H-  
5M*q{kX)  
public void run() .DCp)&m l;  
{ l.b  
while(nStartPos < nEndPos && !bStop) %Sxy!gGz%%  
{ vjbot^W9  
R)G'ILneV  
,cgC_ %  
try{ *1%=?:$(r6  
URL url = new URL(sURL); `M"b L|[R  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1gH5#_ ?  
httpConnection.setRequestProperty("User-Agent","NetFox"); 213D{#2  
String sProperty = "bytes="+nStartPos+"-"; [xM07%:  
httpConnection.setRequestProperty("RANGE",sProperty); )mwY] !  
Utility.log(sProperty); r_ r+&4n  
EYG&~a>L*  
r|0C G^:C  
InputStream input = httpConnection.getInputStream(); c|ZZ+2IYd  
//logResponseHead(httpConnection); ChGwG.-%L  
zCPjuS/~ Q  
$m{\<A  
byte[] b = new byte[1024]; t41\nTZr  
int nRead; 8v(Xr}q,r  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "B)DX*-\?  
{ 9YB~1 M  
nStartPos += fileAccessI.write(b,0,nRead); AGrGZ7p]  
//if(nThreadID == 1) & }k=V4L  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w )DO"Z7  
} ?;uzx7@F  
/?2yo{F g  
t"RgEH@  
Utility.log("Thread " + nThreadID + " is over!"); ilFM+x@  
bDownOver = true; ?Vt$  
//nPos = fileAccessI.write (b,0,nRead); S,Tm=} wj  
} ?V*>4A  
catch(Exception e){e.printStackTrace ();} qxd{c8  
} & +%CC  
} ]l+2Ca:-[j  
<|.S~HLTQ  
=X+DC&]%!  
//打印回应的头信息 (m.]0v*&c  
public void logResponseHead(HttpURLConnection con) 6jF~zI^  
{ F(SeD)ml  
for(int i=1;;i++) 4 Ag+  
{ T_YN^za(q  
String header=con.getHeaderFieldKey(i); <-FZ-asem  
if(header!=null) xB9^DURr\  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }3)$aI_  
Utility.log(header+" : "+con.getHeaderField(header)); ~zYp(#0op  
else |bd5aRS9  
break; |L]dJ<  
} U0)(k}Q)  
} RZ?>>Ll6  
5'oWd e  
Ep0Aogp29  
public void splitterStop() `bt]v$  
{ QRt(?96  
bStop = true; 3OM\R%M  
} >E)UmO{S  
GI6 EZ}.MZ  
 hA/FK  
} ZO0_:T#Z  
ixfkMM ,W  
C"0gAN  
/* dcXtT3,kpX  
**FileAccess.java oZOFZ-<  
*//文件访问(定位,写) `=CF | I  
package NetFox; H<1C5-  
import java.io.*; M5P63=1+  
45ct*w  
/md`tqI>i<  
public class FileAccessI implements Serializable{ -,XS2[  
~r>WnI:vg  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 's&Vg09D,  
RandomAccessFile oSavedFile; !q7M+j4  
long nPos; @ ?e;Jp9  
hXM C!~Th  
[3/P EDkw  
public FileAccessI() throws IOException c~$ipX   
{ CQv [Od  
this("",0); Tri.>@-u  
} tQ|b?3  
sav2.w  
e=2;z  
public FileAccessI(String sName,long nPos) throws IOException 4)XN1r:  
{ ?*4]LuK6  
oSavedFile = new RandomAccessFile(sName,"rw"); 6^ /C+zuX  
this.nPos = nPos; -u8@ .  
oSavedFile.seek(nPos); ~zRW*pd  
} yK}#|b'cM  
59EAqz[:  
T /] ayc:  
public synchronized int write(byte[] b,int nStart,int nLen) ^2=Jv.2{|  
{ ? 4.W _  
int n = -1; L(8Q%oX%o  
try{ Zr$PSp}  
oSavedFile.write(b,nStart,nLen); BwL: B\  
n = nLen; "`&?<82  
} KDn`XCnk,  
catch(IOException e) KNK0w5  
{ [n< U>up  
e.printStackTrace (); pwu5Fxn)  
} uIWCVR8`Y  
67n1s  
Zj}DlNkVu  
return n; 'nCBLc8  
} kB~ :HQf  
y:v0& 9L  
.#+rH}=Z  
} lhxhAe  
J@R+t6$3O  
$jw!DrE  
/* bBDgyFSI <  
**SiteInfoBean.java *1elUI2Rg  
*/ &Nec(q<  
package NetFox; @A yC0}  
h,\_F#hi  
7p~@S4  
public class SiteInfoBean { 6X'RCJu%  
Mr`u!T&sc  
sA` bPhk  
private String sSiteURL; //Site's URL ^K;,,s;0  
private String sFilePath; //Saved File's Path S&R~*  
private String sFileName; //Saved File's Name g/Qr] :;  
private int nSplitter; //Count of Splited Downloading File p R~PB  
/,B"H@ J  
[u-~<80  
public SiteInfoBean() &[kwM3 95  
{//nSplitter的缺省值为5 *1>XlVx,  
//default value of nSplitter is 5 fEgZ/p!g  
this("","","",5); D6v0n6w  
} O'!k$iJNb  
}uZh oA  
q WP1i7]=/  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WQ6E8t)  
{ S&]JY  
sSiteURL= sURL; blS*HKw  
sFilePath = sPath; >~ne(n4qy  
sFileName = sName; ~v<r\8`OI2  
this.nSplitter = nSpiltter; z3a te^PJF  
0gt/JI($  
x.45!8Zb  
} OP<@Xz  
P;A"`Il  
a+J :1'  
public String getSSiteURL() o 'yR^`  
{ xat)9Yb}0  
return sSiteURL; hDz_BvE  
} }F@`A?k  
S Xgpj  
/e\} qq  
public void setSSiteURL(String value) Jk(b=j  
{ W_M]fjL.  
sSiteURL = value; iRPd=)  
} hbN*_[  
SHh g&~B  
{_Ke'" k  
public String getSFilePath() =Ybbh`$<  
{ Iy e  
return sFilePath; Wp >W?'`  
} |!&,etu  
`uGX/yQ#=  
6 rmK_Y  
public void setSFilePath(String value) 8mx5K-/,y^  
{ ! 4i  
sFilePath = value; v< ;, x  
} BHU(Hd  
}g(aZ  
spFsrB  
public String getSFileName() x}F.<`  
{ "7gS*v,r  
return sFileName; GK\'m@k  
} V1j&>-]]9*  
Ry/NfF=  
&Vl,x/  
public void setSFileName(String value) 7b Gzun&  
{ l`,`N+FG  
sFileName = value; f'r/Q2{n  
} 5t0i/&zX  
!.p!  
,[~Ydth  
public int getNSplitter() m,=$a\UC  
{ `DJIY_{-2  
return nSplitter; hW/*]7AM^  
} z.[L1AGa|s  
H&%=>hyX  
Bt.W_p  
public void setNSplitter(int nCount) S%Ja:0=}?  
{ #=$4U!yL  
nSplitter = nCount; ydlH6>  
} M2V.FYV{j>  
} 8N|*n"`}  
L@G)K  
SxQ|1:i%  
/* s$Roe(J  
**Utility.java VgoQz]z  
*/ %/'[GC'y!  
package NetFox; +mxsjcq0  
` 6"\.@4  
3V,X=  
public class Utility {  W#??fae  
H|,{^b@9  
!!` zz  
public Utility() f \4Qp  
{ S - 7JDE>  
{CGk5`g~  
gc(1,hv  
} 9jvg[ H  
kfmIhHlYQ  
//线程睡眠 *nC<1.JW  
public static void sleep(int nSecond) BkO"{  
{ 89 SsSb  
try{ WUqAPN  
Thread.sleep(nSecond); }1$8)zH  
} s&fU|Jk8  
catch(Exception e) )3u[btm  
{ WMI/Y 9N  
e.printStackTrace (); FyY;F;4P  
} h eh! cDK  
} i.fDH57  
6 a$%  
//日志 c9ghR0WM  
public static void log(String sMsg) }f({03$  
{ ,fYO>l';`f  
System.err.println(sMsg); )p!dql K  
} uM4,_)L  
4Uwt--KtFh  
{'vvE3iZ  
public static void log(int sMsg) E+3~w?1  
{ -R\}Q"  
System.err.println(sMsg); 1hMk\ -3S  
} MM5#B!BB  
} {O"dj;RU  
16aaIK  
9ge$)q@3  
/* Xt~/8)&  
**TestMethod.java Xi|v!^IT  
*/ wTTQIo 60  
package NetFox; [jLx}\]  
8zY)0  
NuXU2w~  
public class TestMethod { kW(8i}bg  
oiR` \uY  
UbuxD})  
public TestMethod() \LS%bO,Y|  
{ ///xx/weblogic60b2_win.exe I~mw\K{.3M  
try{ "/\:Fdc^  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dk7"#q@kx  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iu:e>r  
SiteFileFetch fileFetch = new SiteFileFetch(bean); o@>5[2b4  
fileFetch.start(); bRIb'%=+GA  
} nDPfr\\  
catch(Exception e){e.printStackTrace ();} AM}OL Hj  
3Y r   
) .]Z}g&  
} ?s_q|d_  
q|6lw 74`  
X'3F79`  
public static void main(String[] args) *J$=UG,u  
{ D1Fc7! TV  
new TestMethod(); BS{">lPmx  
} {!EbGIh  
} vR`KRI`{  
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