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http断点续传简单实现(java)

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/* CD:@OI  
**SiteFileFetch.java AA:Ch?  
*/ Z f4Xt Yn  
package NetFox; "i<i.6|  
import java.io.*; Jk!}z+X'A  
import java.net.*; wv|:-8V  
/lCn^E6-  
?{mFQ  
public class SiteFileFetch extends Thread { N1jj\.nB  
%u-l6<w# R  
FZ DC?  
SiteInfoBean siteInfoBean = null; //文件信息Bean nzmv>s&UW  
long[] nStartPos; //开始位置 w&8gA[y*u  
long[] nEndPos; //结束位置 v[T5D:  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ~M6Q8Y9  
long nFileLength; //文件长度 lY yt8H  
boolean bFirst = true; //是否第一次取文件 $cHA_$ `  
boolean bStop = false; //停止标志 [RiCa  
File tmpFile; //文件下载的临时信息 MM"{ehd{^a  
DataOutputStream output; //输出到文件的输出流 a.L ?J  
2VyLt=mdh  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) f*04=R?w7>  
public SiteFileFetch(SiteInfoBean bean) throws IOException UxzZr%>s  
{ oIdMDp^$  
siteInfoBean = bean; 1tHTjEG4^3  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 8QV+DDZx  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); RcitW;{|Kg  
if(tmpFile.exists ()) ;]3Tuq  
{ KGS=(z  
bFirst = false; /m%i"kki  
read_nPos(); *IJctYJaX  
} <\|f;7/  
else ZY-W~p1:G  
{ ,~w)~fMb8  
nStartPos = new long[bean.getNSplitter()]; x3xBl_t  
nEndPos = new long[bean.getNSplitter()]; *q{/`Z{wy  
} 9]r6V   
ZMQSy7  
DJr{;t$7~  
{wiw]@c8  
} !U>711$  
v?F~fRH  
6H\3  
public void run() .-T^ S"`d|  
{ LSv0zAIe/  
//获得文件长度 0&E{[~Pv  
//分割文件 J b Hn/$  
//实例FileSplitterFetch \b?z\bC56  
//启动FileSplitterFetch线程 "yxIaTZu  
//等待子线程返回 glbU\K> >  
try{ _[zO?Div[  
if(bFirst) @{\q1J>  
{ >_XRh  
nFileLength = getFileSize(); B v /]>Z  
if(nFileLength == -1) );$_|]#  
{ h1} x2  
System.err.println("File Length is not known!"); >y#<WB$i  
} wyeiz7  
else if(nFileLength == -2) ;  6Js   
{ {.v-  
System.err.println("File is not access!"); f5<qF ]Y/  
} \^or l9  
else DfgqB3U[  
{ z@iu$DZ  
for(int i=0;i<nStartPos.length;i++) xH!{;i  
{ 5rK7nLb  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 1nhC! jDD  
} ;0(|06=  
for(int i=0;i<nEndPos.length-1;i++) *6=2UJcJ  
{ ,{MA90!  
nEndPos = nStartPos[i+1]; /MKcS%/H/  
} gF+Uj( d  
nEndPos[nEndPos.length-1] = nFileLength; WQv%57+  
} @U08v_,  
} #G%[4.$n.  
_"%mLH=!8  
TC;2K,.#k  
//启动子线程 4Z5ZV!  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9#L0Q%,*  
for(int i=0;i<nStartPos.length;i++) JJ[.K*dO  
{ H z&a~  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eD5.*O  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {0 d/;  
nStartPos,nEndPos,i); &[ejxK"  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2'UWPZgE  
fileSplitterFetch.start(); Sa7bl~p\  
} g0NtM%  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o5)lTVQ~~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sr1`/  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ")T;3/c  
nEndPos = " + nFileLength); :^]rjy/|+  
// fileSplitterFetch[nPos.length-1].start(); 'M+iw:R__  
b"n0Yk1  
{Hg.ctam  
//等待子线程结束 .6z8fjttOC  
//int count = 0; tJ`tXO  
//是否结束while循环 w6(E$:#d  
boolean breakWhile = false; C)66 ^l!x  
PLlad\  
Y3^UJe7E  
while(!bStop) p(o"K@I  
{ L ldZ"%P  
write_nPos(); _3v6c  
Utility.sleep(500); }xXUCU<  
breakWhile = true; 8i"v7}  
 _dCdyf  
>qkZn7C   
for(int i=0;i<nStartPos.length;i++) CR3<9=Lv>  
{ YQGVQ[P  
if(!fileSplitterFetch.bDownOver) I~ Q2jg2  
{ ?T]3I.3 2^  
breakWhile = false; ?Co)7}N  
break; FJxg9!%d  
} [xW;5j<87  
} yh~*Kt]9Ya  
if(breakWhile)  1$nlRQi  
break; 4+Aht]$hC  
ehe hTP  
~5S[Sl  
//count++; &[QvMh  
//if(count>4) 3fA.DK[4[  
// siteStop(); WrJgU&H{  
} =UY)U-  
l12Pj02w  
#pDWwnP[rt  
System.err.println("文件下载结束!"); /,#HGu]q'  
} =GH>-*qp  
catch(Exception e){e.printStackTrace ();} ((OQs.  
} /o@6? UH  
W.u+R?a=  
xv|?;Zf6w  
//获得文件长度 x~3N})T5  
public long getFileSize() ;\1/4;m  
{ hc#Lni R3$  
int nFileLength = -1; nX 4WlH  
try{ REqQJ7a/  
URL url = new URL(siteInfoBean.getSSiteURL()); C{Y0}ZrmlF  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 39Nz>Nu:  
httpConnection.setRequestProperty("User-Agent","NetFox"); U~h f,Oxi  
:De@_m  
ktE~)G  
int responseCode=httpConnection.getResponseCode(); !j8.JP}!)  
if(responseCode>=400) j~DTvWg<Jl  
{ EyU5r$G  
processErrorCode(responseCode); ol^uM .k%_  
return -2; //-2 represent access is error vlW521  
} S)`%clN}J  
w4I&SLm-b  
ha Tmfh_|  
String sHeader; #GoZH?MAF  
7S^ba  
wg-qq4Q\  
for(int i=1;;i++) OGA_3|[S   
{ .AHf]X0  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ')G, +d^  
//Utility.log(in.readLine()); =17d7#-  
sHeader=httpConnection.getHeaderFieldKey(i); 0<ze'FbV]  
if(sHeader!=null) 04o>POR  
{ K14FY2"  
if(sHeader.equals("Content-Length")) jg)+]r/hS  
{ 3:H[S_q  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Mk=M)d`  
break; r1pj-   
} >]/RlW[  
} 0Wd2Z-I  
else C_5o&O8Bc  
break; %X|fp{C  
} kh7RQbNY<I  
} Z+8Q{|Ev  
catch(IOException e){e.printStackTrace ();} kJP` C\4}f  
catch(Exception e){e.printStackTrace ();} A[7\!bq5  
p"'knZ G  
&|]GTN`E  
Utility.log(nFileLength); m/E$0tf  
9-B/n0  
e^ Aw%t  
return nFileLength; FqWW[Bgd  
} d+m}Z>iQ1O  
}Mv$Up  
P]A~:Lj  
//保存下载信息(文件指针位置) +Oxw?`I$  
private void write_nPos() 5u5-:#sLy  
{ '?gF9:  
try{ l.>3gjr  
output = new DataOutputStream(new FileOutputStream(tmpFile)); A r=P;6J  
output.writeInt(nStartPos.length); ZBY*C;[)*P  
for(int i=0;i<nStartPos.length;i++) dp|VQWCq  
{ jV 'u*2&9  
// output.writeLong(nPos); "z8iuF  
output.writeLong(fileSplitterFetch.nStartPos); `<#Ufi*c  
output.writeLong(fileSplitterFetch.nEndPos); xU6rZ CqE  
} " J4?Sb<  
output.close(); d~QZc R  
} z JBcz,  
catch(IOException e){e.printStackTrace ();} +<})`(8  
catch(Exception e){e.printStackTrace ();} 6?`3zdOeO  
} c*!xdK  
6&,{"N0 T  
Jc=~BT_G  
//读取保存的下载信息(文件指针位置) eV5 e:9  
private void read_nPos() v?@=WG  
{ 6,raRg6  
try{ l_lK,=cLj+  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y$,j'B:;4m  
int nCount = input.readInt(); =".sCV9"N  
nStartPos = new long[nCount]; Dug{)h_2  
nEndPos = new long[nCount]; AqZ()p*z  
for(int i=0;i<nStartPos.length;i++) )x<oRHx]  
{ )k~{p;Ke  
nStartPos = input.readLong(); 1m{c8Z.h/d  
nEndPos = input.readLong(); dq4t@:\o0  
} 6uu49x_^L4  
input.close(); ^1\[hyZ!  
} hpBn_  
catch(IOException e){e.printStackTrace ();} A+QOox]<  
catch(Exception e){e.printStackTrace ();} Io*mFa?  
} ~a ]R7X7  
} Q1m  
Fs_zNN  
private void processErrorCode(int nErrorCode) Ly~s84k_po  
{ cT.8&EEW  
System.err.println("Error Code : " + nErrorCode); )e?6 Ncy  
} 6j6P&[  
@xkI?vK6  
 m1#,B<6  
//停止文件下载 u-k!h  
public void siteStop() Ir?ehA  
{ 1i=p5,|  
bStop = true; 4 yDWVd;  
for(int i=0;i<nStartPos.length;i++) y**>l{!!  
fileSplitterFetch.splitterStop(); I AFj_VWC0  
j"4]iI+{"  
+'`I]K>  
} Yw6d-5=:  
} W5U;{5  
//负责部分文件的抓取 i}_d&.DbF  
**FileSplitterFetch.java Y{`hRz`  
*/ aSM S uX8  
package NetFox; XJguw/[wm  
+rOfQ'lQ  
Pm=i(TBS/  
import java.io.*; q+1SU6x'm  
import java.net.*; 52v@zDY  
A5 <T7~U  
nK>D& S_!  
public class FileSplitterFetch extends Thread { (@3?JJ]1  
hNL_ e3  
J]gtgt^   
String sURL; //File URL ZK?:w^Z  
long nStartPos; //File Snippet Start Position j=V2~ xA6  
long nEndPos; //File Snippet End Position Lv<)Dur0K  
int nThreadID; //Thread's ID _n12Wx{  
boolean bDownOver = false; //Downing is over g7`uWAxZa  
boolean bStop = false; //Stop identical lfe^_`ij(+  
FileAccessI fileAccessI = null; //File Access interface e)Pm{:E  
'l41];_  
Vd+5an?  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G&,2>qxK R  
{ ibxtrt=  
this.sURL = sURL; NVG`XL  
this.nStartPos = nStart; Zoyo:vv&  
this.nEndPos = nEnd; jx-8%dxtZ  
nThreadID = id; k}908%w  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0$I!\y\  
} mF@D O$  
B[{Ie G'  
;o?Wn=J  
public void run() | X0Ys8f  
{ mP+rPDGp  
while(nStartPos < nEndPos && !bStop) [+ N 5  
{ O#@KP"8  
F^}n7h=qk  
r57rH^Hc  
try{ _^Lg}@t  
URL url = new URL(sURL); ]M.)N.T  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %q5iy0~P  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5%%A2FrB.S  
String sProperty = "bytes="+nStartPos+"-"; s[tFaB1  
httpConnection.setRequestProperty("RANGE",sProperty); 1`@rAA>h'  
Utility.log(sProperty); v}^ f8nVR  
* ~4m!U_s  
-"X} )N2  
InputStream input = httpConnection.getInputStream();  0ZpWfL  
//logResponseHead(httpConnection); ^J7g)j3  
VkDFR [k_  
d){Al(/  
byte[] b = new byte[1024]; *N?y<U  
int nRead; GcA!I!j/  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a&~]77)  
{ )`gE-udR  
nStartPos += fileAccessI.write(b,0,nRead); $C?G7Vs  
//if(nThreadID == 1) Q =cbHDB  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,';+A{aV  
} 5jBBk*/\  
_=oNQ  
Gj(UA1~1  
Utility.log("Thread " + nThreadID + " is over!"); n:5*Tg9  
bDownOver = true; zV=(e( [  
//nPos = fileAccessI.write (b,0,nRead); 6P:H`  
} ;3k6_ub  
catch(Exception e){e.printStackTrace ();} G9uWn%5r  
} KqT~MPl  
} 8L}N,6gC4_  
Zjh9jvsW  
/DQcM.3  
//打印回应的头信息 OJ\rT.{  
public void logResponseHead(HttpURLConnection con) u#m(Py  
{ )#n>))   
for(int i=1;;i++) ?G>#'T[  
{ M[ZuXH}  
String header=con.getHeaderFieldKey(i); [j`-R 0Np  
if(header!=null) Cb/?hT  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @5-+>\Hd^t  
Utility.log(header+" : "+con.getHeaderField(header)); /,Sd  
else !saKAb}d7H  
break; .+c YzS] !  
} sw@* N  
} S.Fip _  
]0wmvTR  
6lc/_&0  
public void splitterStop() &Jw4^ob  
{ lt&30nf=  
bStop = true; I NE,/a=  
} ~IE5j,SC  
,w/f :-y  
'd@Vusq}2  
} umWZ]8  
7F{=bL  
@tLoU%  
/* 4)3!n*I  
**FileAccess.java y[!4M+jj  
*//文件访问(定位,写) 4';]fmf@[i  
package NetFox; >MIp r  
import java.io.*; ~-w  
<#9zc'ED:  
:`ysq  
public class FileAccessI implements Serializable{ w5(GRAH  
Z0e+CEzq  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 HG%H@uK  
RandomAccessFile oSavedFile; IJnr^S8  
long nPos; J}.y+b>8\  
fV.43E  
db!2nImNu\  
public FileAccessI() throws IOException }PY? ZG  
{ aUy=D:\  
this("",0); OQh36BM  
} r4xq%hy  
B&m?3w  
O:a$ U:  
public FileAccessI(String sName,long nPos) throws IOException wzMWuA4vX  
{ Y e}y_W  
oSavedFile = new RandomAccessFile(sName,"rw"); n~d`PGs?f  
this.nPos = nPos; */L;6_  
oSavedFile.seek(nPos); NW9k.D%  
} e-o s0F  
1*x4T%RF$  
H\3CvFm  
public synchronized int write(byte[] b,int nStart,int nLen) m(3bO[u1  
{  1Nk}W!v  
int n = -1; (t9qwSS8z  
try{ Tj{!Fx^H  
oSavedFile.write(b,nStart,nLen); w I@ lO\  
n = nLen; lm&C!{K  
} 9& W\BQ  
catch(IOException e) 7OOB6[.fu  
{ 3RRZVc* ^  
e.printStackTrace (); ,U'Er#U  
} ' U)~|(\i  
fXw%2wg  
+WwQ!vWWd  
return n; -c=IO(B/  
} T[XI  
5.|rzk>  
w'5~GhnP+  
} xL>0&R  
=I/J !}.  
ZF;S}1  
/* 5Tp n`2F  
**SiteInfoBean.java |U^ ff^]  
*/ 2uWzcy ?F  
package NetFox; 5Kv=;o=U  
wrn[q{dX  
h3 p 3~xq  
public class SiteInfoBean { "eQ96^'J  
!*|CIxk(  
y::;e#.  
private String sSiteURL; //Site's URL ~9oS~fP?I  
private String sFilePath; //Saved File's Path =QyO$:t  
private String sFileName; //Saved File's Name IFPywL{K  
private int nSplitter; //Count of Splited Downloading File ~ilbW|s?=k  
(p14{  
N"t, 6tH  
public SiteInfoBean() aXC`yQ?  
{//nSplitter的缺省值为5 )hQNIt3o_  
//default value of nSplitter is 5 ~N'KIP[W  
this("","","",5); XE$eHx3;  
} e`$v\7K  
~:)$~g7>b  
:M3l#`4Q  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O:7y-r0i  
{ 6g$04C3tHi  
sSiteURL= sURL; ~*B1}#;  
sFilePath = sPath; z7PPwTBa  
sFileName = sName; lGLZIp  
this.nSplitter = nSpiltter; RFK N,oB  
\\)-[4uC  
/2HwK/RZ  
} S|]~,l2]}  
Gs?W7}<$  
9$DVG/  
public String getSSiteURL() Zc9 n0t[  
{ I;-{#OE,  
return sSiteURL; ?$n<vF>  
} 1|gP :t}  
KUyua~tF  
~+lC %R  
public void setSSiteURL(String value) =_yOX=g|  
{ N%B#f\N  
sSiteURL = value; 8:&@MZQ&!  
} TVFGonVY  
,XA;S5FE  
Pm?6]] 7  
public String getSFilePath() ,+X8?9v  
{ c~RIl5j  
return sFilePath; |nt J+  
} Pucf0 #  
*q0N$}k  
_~cmR<  
public void setSFilePath(String value) OC>" +  
{ Jx>P%>+<j  
sFilePath = value; <m(nZ'Zqz2  
} r\3In-(AT  
huTJ a2  
E>g'!  
public String getSFileName() zWY6D4   
{ @W @L%<  
return sFileName; g{J3Ba  
} 9M7P]$^  
ev?>Nq+Z  
d;;=s=j  
public void setSFileName(String value) )nJ>kbO~8  
{ @P.l8|w  
sFileName = value; vGAPQg6*  
} ?APzx@$D.  
Qp=uiXs  
cn\_;TYiJ  
public int getNSplitter() %eah=e  
{ lT:<ZQyjT  
return nSplitter; rzTyHK[  
} 3?geJlD4  
?B}>[  
TRq~n7Y7C  
public void setNSplitter(int nCount) !c&^b@ yw  
{ $o@?D^  
nSplitter = nCount; U=yD!  
} uo{QF5z]  
} =az$WRV+7!  
u3ZG;ykM  
Fu`g)#Z  
/* I&xRK'  
**Utility.java Q.|2/6hD7[  
*/ HIU@m<  
package NetFox; |-|BM'Y  
A |&EI-In  
VC+\RB#:-  
public class Utility { ;|^fAc~9{r  
-12v/an]L7  
1=D!C lcb  
public Utility() lR(&Wc\j  
{ ?SAi t Q3  
fBF}-{VX(  
i Bi/9  
} L9kP8&&KK  
)} #r"!  
//线程睡眠 LH_2oJ\  
public static void sleep(int nSecond) CeJ|z {F\  
{  A:!{+  
try{ >r*Zm2($MR  
Thread.sleep(nSecond); s=nds"J  
} c1 <g!Q&E  
catch(Exception e) 7/1S5yUr|  
{ ?~K2&eo  
e.printStackTrace (); P:=AD W c  
} B';Ob  
} 'I~dJEW7  
%qQ(@TG  
//日志 4mAtYm  
public static void log(String sMsg) %G@aZWk Sa  
{ @$*c0 . |z  
System.err.println(sMsg); a9I8W Q   
} meL'toaJdQ  
"+WR[-n>\  
'!I?C/49k  
public static void log(int sMsg) 8tL61x{]  
{ L8G4K)  
System.err.println(sMsg);  4{?x(~  
} 4_Jdh48-d  
} c5;ROnTm  
$>UzXhf}\  
Jc)1}  
/* Dk-L4FS  
**TestMethod.java c`.:"i" k3  
*/ r&[~/m8zl  
package NetFox; la4 ,Z  
HA%ye"(y8  
Esjv^* v9-  
public class TestMethod { W% [5~N  
O,{ (  
#J!? :(m:  
public TestMethod() [jw o D  
{ ///xx/weblogic60b2_win.exe ;Ki1nq5c#s  
try{ w}0Qy  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q{ hq.KZ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $ T4PC5.  
SiteFileFetch fileFetch = new SiteFileFetch(bean); .+|DN"PgJ  
fileFetch.start(); hLvv:C@  
} O2G+ '  
catch(Exception e){e.printStackTrace ();} 5dF=DCZ  
,7(/Il9  
`O{Uz?#*x  
} <@A^C$g  
"!tB";n  
Mb>XM7}PU  
public static void main(String[] args) +7^Ul6BB#K  
{ .{ -yveE  
new TestMethod();  M9K).P=  
} v,+@ U6i  
} C\^K6,m5  
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