http断点续传简单实现（java)

/* d|NW&PG  
**SiteFileFetch.java N { oVz],  
*/ :zKW[sF  
package NetFox; 1}=D  
import java.io.*; apa&'%7  
import java.net.*; :Pdh##k  
I8J>>H'#A  
H;nzo3x  
public class SiteFileFetch extends Thread { Zwc&4:5%  
?Xypn#OPt  
Y`ip.Nx  
SiteInfoBean siteInfoBean = null; //文件信息Bean Bzwll  
long[] nStartPos; //开始位置 /C!~v!;e  
long[] nEndPos; //结束位置 9S]pC?N]E  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 U U_0@V<  
long nFileLength; //文件长度 /=6_2t#vA  
boolean bFirst = true; //是否第一次取文件 U%:%. Bys  
boolean bStop = false; //停止标志 [
l5jPL}6  
File tmpFile; //文件下载的临时信息 ~q566k!Ll!  
DataOutputStream output; //输出到文件的输出流 9/0H,qZc  
*>=tmW;%  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） @9 S ::  
public SiteFileFetch(SiteInfoBean bean) throws IOException *J[P#y  
{ vm+3!s:u  
siteInfoBean = bean; C<^i`[&P$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Sr6'$8#>Y  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); fL2P6N@  
if(tmpFile.exists ()) !ZUUn*e{5  
{ |(%<FY$  
bFirst = false; )m7%cyfC  
read_nPos(); x!GDS>  
} g3
kbsi7_:  
else Gpxp8[ {  
{ U!|)M  
nStartPos = new long[bean.getNSplitter()]; lot`6]  
nEndPos = new long[bean.getNSplitter()]; @ ,X/Wf  
} ZzE(S  
wd*B3  
jV*10kM<  
[IOI&`?D  
} y{mt *VA4  
e x Z/  
GqCBD-@4v.  
public void run() F(`|-E"E;  
{ np^&cY]  
//获得文件长度 b_ZvI\H  
//分割文件 a.%ps:  
//实例FileSplitterFetch 6NV592  
//启动FileSplitterFetch线程 s7 nl  
//等待子线程返回 G]aey>)  
try{ ~Re4
zU  
if(bFirst) Fc`IRPW<  
{ ++,I`x+p  
nFileLength = getFileSize(); A` _d
j}UF  
if(nFileLength == -1) 6t;;Fz  
{ q("XS  
System.err.println("File Length is not known!"); $5G(_   
} Iz+%wAZ|B6  
else if(nFileLength == -2) O/#3QK  
{ 9~~NxWY%x  
System.err.println("File is not access!"); 3#,6(k4>  
} dM^EYW  
else Cty{  
{ *Ze0V9$'  
for(int i=0;i<nStartPos.length;i++) )KFxtM-  
{ tj
ThQ  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); V6dq8Z"h  
} Fj<*!J$,  
for(int i=0;i<nEndPos.length-1;i++) HQ"T>xb  
{ 'm*
W<  
nEndPos = nStartPos[i+1]; QTa\&v[f  
} B;[ .u>f  
nEndPos[nEndPos.length-1] = nFileLength; ldTXW(^j  
} _0Ea 3K  
} O)&W0`VY  
-b!Z(}JK  
^)]U5+g?  
//启动子线程 F,S)P`?  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u=nd7:bv  
for(int i=0;i<nStartPos.length;i++) K
.QSt  
{ zl8M<z1`1  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ti)Me-g  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5?H8?~&dz  
nStartPos,nEndPos,i); z#&1>  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9cB+x`+Lu  
fileSplitterFetch.start(); 9oc_*V0<  
} NL:-3W7vf  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {?lndBP<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w3q'n%  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tUH?N/qn  
nEndPos = " + nFileLength); \9`E17i  
// fileSplitterFetch[nPos.length-1].start(); _(g0$vRP~  
=M-=94  
E'4Psx9: =  
//等待子线程结束 toGd;2rl  
//int count = 0; rtAPkXJFM  
//是否结束while循环 O#;sY`fy_M  
boolean breakWhile = false; 
U:8]G  
4Lg ,J9  
!{+CzUo@  
while(!bStop) %2dzx[s  
{ Qqg.z-G%.  
write_nPos(); giu{,gS0?M  
Utility.sleep(500); #%QHb,lhl  
breakWhile = true; %C`P7&8m=O  
W2rd[W  
LQk^l`  
for(int i=0;i<nStartPos.length;i++) LTS{[(%  
{ &Cb,C+q  
if(!fileSplitterFetch.bDownOver) M7?ktK9`ma  
{ {E%c%zzQ  
breakWhile = false; IH=$ wc  
break; XcT!4xG0  
} DqWy@7 a  
} C~4SPCU  
if(breakWhile) rP]|`*B  
break; _D}3``  
4o M~  
Lqxhy s  
//count++; vrb@::sy0T  
//if(count>4) v\|jkzR5Y  
// siteStop(); `w#VYs|k  
} TO89;O  
\{ | GK  
0<v5_pB  
System.err.println("文件下载结束！"); PP$2s]{  
} AP%R*0]  
catch(Exception e){e.printStackTrace ();} >?K=l]!(*  
} })<u~r  
O^CBa$  
uQc("F  
//获得文件长度 F-zIzzb&O  
public long getFileSize() v#{Nh8n  
{ U -OD  
int nFileLength = -1; -V;Y4,:c  
try{ ox`Zs2-a  
URL url = new URL(siteInfoBean.getSSiteURL()); ppn  8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <QvVPE}z   
httpConnection.setRequestProperty("User-Agent","NetFox"); RuYIG?J=/  
67&IaDts  
uMva5o  
int responseCode=httpConnection.getResponseCode(); ]/Nt  
if(responseCode>=400) 7xO05)bz  
{ _+9i  
processErrorCode(responseCode); |U1 [R\X  
return -2; //-2 represent access is error A z@@0  
} :|kO}NGM  
;b65s9n^b  
*w0|`[P+h  
String sHeader; *
(5;5r  
@!oN]0`F;  
\( V1-,  
for(int i=1;;i++) I,#E`)  
{ i[9gcL"  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @,1_CqV  
//Utility.log(in.readLine()); %T>@Ldt  
sHeader=httpConnection.getHeaderFieldKey(i); `lE&:)  
if(sHeader!=null) I~F&@  
{ ,nL~?h-Zh  
if(sHeader.equals("Content-Length")) j[i*;0) |  
{ p5E okh  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !yj1X Ar  
break;  ij:a+T  
} @C@9Tw2Y  
} QyL]-zNg  
else oy jkk  
break;
*LhwIY  
} 3<<wHK;)  
} 9^g8VlQdT  
catch(IOException e){e.printStackTrace ();} r3?8nQ$  
catch(Exception e){e.printStackTrace ();} +|bmUm<2  
`^{G`es  
5'f_~>1Wt  
Utility.log(nFileLength); H0inU+Ih  
|)To 0Z  
MkFWZ9c3  
return nFileLength; 3HXeBW  
} V<|N}8{Z2a  
pSC{0Y$g  
~rO&Y{aG#  
//保存下载信息（文件指针位置） 9\?&u_ U"  
private void write_nPos() EsWB|V>  
{ @F(e
r  
try{ :tO?+
1  
output = new DataOutputStream(new FileOutputStream(tmpFile)); !]s=9(O  
output.writeInt(nStartPos.length); <<S4l~"o  
for(int i=0;i<nStartPos.length;i++) cd,'37pZ  
{ cHr]{@7Cs  
// output.writeLong(nPos); YIW9z{rrs  
output.writeLong(fileSplitterFetch.nStartPos); XsJ`x  
output.writeLong(fileSplitterFetch.nEndPos); d(t)8k$  
} Y_faqmZ9]  
output.close(); =>PX~/o  
} W (TTsnnx  
catch(IOException e){e.printStackTrace ();} .(Ux1.0C  
catch(Exception e){e.printStackTrace ();} >.P*lT  
} qU6!vgM&  
gmu.8  
b/*QV0(  
//读取保存的下载信息（文件指针位置） q*R~gEi#yk  
private void read_nPos() i/ o  
{ `2U,#nZ 4  
try{ V9<E`C  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); chD7^&5]  
int nCount = input.readInt(); } %0w25  
nStartPos = new long[nCount]; *{5}m(5F  
nEndPos = new long[nCount]; `m1stK(PO  
for(int i=0;i<nStartPos.length;i++) {=I,+[(  
{ exSwx-zxI  
nStartPos = input.readLong(); TuCHD~rb  
nEndPos = input.readLong(); 1c"s+k]9  
} @Z$fEG)9  
input.close(); ! weYOOu  
} BYB9M  
catch(IOException e){e.printStackTrace ();} o(v`  
catch(Exception e){e.printStackTrace ();} Z{(Gib~{N  
} !^L}LtqHI  
as3uz  
_d~GY,WTdO  
private void processErrorCode(int nErrorCode) |:(BI5&S  
{ k(>J?\iNW  
System.err.println("Error Code : " + nErrorCode); PNLlJlYlP  
} :.H@tBi*E  
YVRE9  
_`QMEr?  
//停止文件下载 jyg>'"W  
public void siteStop() s
dXchVC  
{ .w\4Th#  
bStop = true; a&[[@1OY  
for(int i=0;i<nStartPos.length;i++) yT3K 2A  
fileSplitterFetch.splitterStop(); i)@vHh82  
/-<]v3J  
1:cq\Y  
} A+Je?3/.  
} ocW`sE?EED  
//负责部分文件的抓取 9|>y[i  
**FileSplitterFetch.java 3H"F~_H  
*/ p(4Ek"  
package NetFox; Q!~1Xc0S`p  
 KYccjX  
b2F1^]p  
import java.io.*; %E,-dw  
import java.net.*; ;ACeY  
{QK9pZB  
k]& I(VQ"  
public class FileSplitterFetch extends Thread { Obc,   
N]c:8dOj  
 h;K9}w  
String sURL; //File URL :1iXBG\  
long nStartPos; //File Snippet Start Position <9=RLENmY"  
long nEndPos; //File Snippet End Position . VI #  
int nThreadID; //Thread's ID Jl"DMUy[kW  
boolean bDownOver = false; //Downing is over t@cBuV`9c  
boolean bStop = false; //Stop identical :i
?c  
FileAccessI fileAccessI = null; //File Access interface Qw%0<~<  
3_VWtGQ  
qj*BV  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /e*<-a  
{ z9#jXC#OdN  
this.sURL = sURL; f}FJR6VO  
this.nStartPos = nStart; R<h0RKiM@  
this.nEndPos = nEnd; OK}8BY  
nThreadID = id; gJOswN;([  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U8g?   
} q|D*H9[ke  
;NJM3g0I  
H~hAm  
public void run() 1nLFtiki  
{ f'Xz4;  
while(nStartPos < nEndPos && !bStop) ^n]?!BdU  
{ 78b9Sdi&  
=(k0^#++G  
hU2N{Ac  
try{ tK <)A)  
URL url = new URL(sURL); @D<Q'7mLh  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~b4fk^u`+  
httpConnection.setRequestProperty("User-Agent","NetFox"); }>j1j^c1='  
String sProperty = "bytes="+nStartPos+"-"; ?~VevD  
httpConnection.setRequestProperty("RANGE",sProperty); UgO\+cI  
Utility.log(sProperty); >yq
L  
oWOH#w  
z#&qWO  
InputStream input = httpConnection.getInputStream(); \}qv}hU  
//logResponseHead(httpConnection); ]@1ncn7N  
RzSN,bLR  
~Uz|sQ*G  
byte[] b = new byte[1024]; :TWHmxch  
int nRead; }S&SL)  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L/cbq*L  
{ %^E>~  
nStartPos += fileAccessI.write(b,0,nRead); `[1]wV5(5@  
//if(nThreadID == 1) [ 06B)|s  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r?2C%GI`  
} X4*/h$48 w  
:Ws3+OI'm3  
Nb{oH+$b  
Utility.log("Thread " + nThreadID + " is over!"); qm}7w3I^  
bDownOver = true; 55|$Imnf  
//nPos = fileAccessI.write (b,0,nRead); g(;ejKSR  
} N=L urXv  
catch(Exception e){e.printStackTrace ();} 7~`6~qg.  
} ae1fCw3k  
} I`KN8ll  
9p$q@Bc  
PwNLJj+%  
//打印回应的头信息 q+G1
#5  
public void logResponseHead(HttpURLConnection con) vqxTf)ys  
{ n#]G!7  
for(int i=1;;i++) anV)$PT=  
{ /ci.IT$Q^  
String header=con.getHeaderFieldKey(i); g-(xuR^*  
if(header!=null) G6Fg<g9:  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )5V1HWjU  
Utility.log(header+" : "+con.getHeaderField(header)); CILk  
else IX3U
\_I#  
break; x[oYN9O  
} >"nk}@  
} #QDV_ziE5  
XJ NKM~
 
,wEM  
public void splitterStop() {k]VT4/  
{ `RzM)ILl  
bStop = true; =XS'V*  
} wYawG$@_  
p9sxA|O=y  
4-n.4j|  
} bKaV]Uy  
SO&;]YO  
EX5kF  
/* D 7E^;W)H  
**FileAccess.java |)_<JAN  
*//文件访问(定位，写) 6qA{l_V  
package NetFox; p_(hM&>C  
import java.io.*; 5Np.&  
XZT( :(  
-T(V6&'Qi  
public class FileAccessI implements Serializable{ ! O>mu6:Rf  
J/*[wj  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e O}mZN  
RandomAccessFile oSavedFile; &\K#UVDyhh  
long nPos; Bms?`7}N  
6u7HO-aa  
y@z#Jw<  
public FileAccessI() throws IOException ^b.J z}  
{ \5l}5<|  
this("",0); d16PY_  
} \d;Ow8%d/  
LMDa68 s  
8+W^t I  
public FileAccessI(String sName,long nPos) throws IOException %~[F^  
{ /L8=8  
oSavedFile = new RandomAccessFile(sName,"rw"); D.GSl  
this.nPos = nPos; u!S{[7 FY  
oSavedFile.seek(nPos); 0&-sz=L  
} #,;k>2j0  
ouI0"R&@  
M;bQid@BG  
public synchronized int write(byte[] b,int nStart,int nLen) pQhv3F  
{ GgYomR:  
int n = -1; }?^G=IP4(  
try{ Z~gqTB]H  
oSavedFile.write(b,nStart,nLen); Mf63 59  
n = nLen; ),Rj@52l  
} &_6:TqJ  
catch(IOException e) f<'C<xnf  
{ G7
<X l}  
e.printStackTrace (); kgu+q\?  
} lb('r"*.  
"
86
9n37  
M@3H]t?  
return n; zYNJF>^<  
} EKf4f^<  
k4P.}SJ?  
V+q RDQ  
} >4E,_`3N  
z,EOyi  
!]nCeo  
/* cG'Wh@  
**SiteInfoBean.java Ww~0k!8,t  
*/ zkOgL9 (_8  
package NetFox; 73.b9mF  
m~K]|]iqQ  
zl[JnVF\6  
public class SiteInfoBean { CAA~VEUL  
L5W>in5(  
$9~1s/('  
private String sSiteURL; //Site's URL one>vi`=  
private String sFilePath; //Saved File's Path GwULtRa/  
private String sFileName; //Saved File's Name -iHhpD9"X  
private int nSplitter; //Count of Splited Downloading File T_-MSXhA  
#rwR)9iC0  
SJ-Sac58r  
public SiteInfoBean() ]lY9[~ v  
{//nSplitter的缺省值为5 loJ0PY'}=  
//default value of nSplitter is 5 wGH@I_cy>  
this("","","",5); DPOPRi~  
} =!X4j3Cv  
ZIp=JR8o$  
u/f&Wq/  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p3o?_ !Z  
{ 96avgyc  
sSiteURL= sURL; luT8>9X^:a  
sFilePath = sPath; 86g+c  
sFileName = sName; c"ztrKQQ  
this.nSplitter = nSpiltter; M=A9ax  
%U7B
0-  
1c!},O  
} ~}*;Ko\  
0Pk-FSY
|f  
Izu.I_$4  
public String getSSiteURL() %K7}yy&9C  
{ cw.7YiU  
return sSiteURL; %"zJsYQ!  
} Biwdb  
$5r,Q{;$  
O@rb4(  
public void setSSiteURL(String value) [4j;FN Fa  
{ v3Yj2LSqx  
sSiteURL = value; Hi9z<l=$  
} 9_3M}|V$^e  
&?6w2[}  
\tx/!tA  
public String getSFilePath() lijy?:__  
{ cG:`Zj~4  
return sFilePath; d ] ;pG(  
} )[*O^bPowI  
\irjIXtV  
F948%?a  
public void setSFilePath(String value) {@AcL:Eit  
{ sBnPS[Oo  
sFilePath = value; <*(R+to^d  
} ZZ*k3Ce  
[B`P]}gL:  
}HorR2(`N  
public String getSFileName() #+0R!Y  
{ >ULp!  
return sFileName; KT71%?P  
} bobkT|s^s  
I:<R@V<~#  
zQ}N mlk  
public void setSFileName(String value) Y +54z/{  
{ Ui!|!V-  
sFileName = value; gUA}%YXe  
} nh)R  
`F8;{`a  
rU@?v+i  
public int getNSplitter() 3H2;mqq  
{ I>Q,]S1h  
return nSplitter; VYo;[ue([  
} /H@")je  
v!A|n3B]p  
wtS*w  
public void setNSplitter(int nCount) ,&]` b#Rc  
{ V JL;+  
nSplitter = nCount; UE w3AO  
} T9-a uK0d  
} yW?%c#9D  
bU`yymf{L  
{+9\o ~  
/* n9!3h?,g  
**Utility.java :0/o?'s  
*/ b]?;R  
package NetFox; 4CT9-2UC  
z,YUguc|  
S=SncMO nE  
public class Utility { y|{?>3  
$ n[7  
:-" jKw  
public Utility() "IJMvTmj  
{ MWh+h7k'  
9mphj)`d;#  
gEHfsR=D6  
} ArzsZ<\//  
d ovwB`5  
//线程睡眠 .MARF  
public static void sleep(int nSecond) _4B iF?1  
{ n@[</E(  
try{ *[:CbFE0y  
Thread.sleep(nSecond); Yka&Kkw
 
} \ZWmef  
catch(Exception e) _J~ta.  
{ ik0Q^^1?Y  
e.printStackTrace (); sNmC#,  
} \'tz|  
} $'{`i5XB  
vqz#V=J{  
//日志 -01 1U!  
public static void log(String sMsg) 0P3|1=  
{ SLOYlRGCi  
System.err.println(sMsg); 9~%]|_(  
} PFgjW
p"Y  
l'".}6S  
42wC."A  
public static void log(int sMsg) b(-t)5^}  
{ }.V0SM6  
System.err.println(sMsg); >@

"3Q`  
} IYg3ve`x  
} Y_>-p(IH  
~V"cLTj"  
U{uWk3I_b  
/* Qwo9>ClC  
**TestMethod.java wDMB  
*/ cW\Y?x   
package NetFox; )k] !
u  
as|c`4r\O  
@j2*.ee  
public class TestMethod { HT=Am  
Yn]yd1  
c$<O0dI  
public TestMethod() To{G#QEgG  
{ ///xx/weblogic60b2_win.exe xc<eU`-'b  
try{ G[<[#$(  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Sb9=$0%\  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /Q>{YsRRB  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3/IWO4?_  
fileFetch.start(); 5QFXj)hR+4  
} 1L=Qg4 H  
catch(Exception e){e.printStackTrace ();} n5*{hi  
b|8>eY  
IQi[g~E.5  
} Nw>T$RzS  
;n7|.O]*  
ivUsMhx>S,  
public static void main(String[] args) -,fa{yt-  
{ $aPHl  
new TestMethod(); ctUF/[_w;  
} CBnouKc:  
} U>_\  
点击下载更多相关资料