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http断点续传简单实现(java)

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/* [lOf|^9  
**SiteFileFetch.java ;fkSrdj  
*/ z[Z2H5[  
package NetFox; T(&kXMaB  
import java.io.*; BP:(IP!&  
import java.net.*; CX.SYr&!R  
SLg+H  
1h{>[ 'L  
public class SiteFileFetch extends Thread { \"J?@  
(`F|nG=X  
uX98iJ  
SiteInfoBean siteInfoBean = null; //文件信息Bean EM=xd~H  
long[] nStartPos; //开始位置 a0{[P$$  
long[] nEndPos; //结束位置 v*vn<nPAQ>  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ,FY-d$3)  
long nFileLength; //文件长度 Y[h#hZ  
boolean bFirst = true; //是否第一次取文件 99a \MH`^  
boolean bStop = false; //停止标志 DQMPAj.  
File tmpFile; //文件下载的临时信息 *3P3M}3~\  
DataOutputStream output; //输出到文件的输出流 HIsB|  
x!`b'U\  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) A1=_nt)5  
public SiteFileFetch(SiteInfoBean bean) throws IOException =hPG_4#  
{ 5^b i 7J  
siteInfoBean = bean; b h*^{  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); `,Xb8^M2  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); xl3zy~;M  
if(tmpFile.exists ()) D{Oq\*  
{ q[Vi[b^F  
bFirst = false; 8s~\iuk  
read_nPos(); Q%I#{+OT  
} hR!}u}ECd  
else \hrrPPD1z  
{ %N>\:8 5?  
nStartPos = new long[bean.getNSplitter()]; 8.[&wy U  
nEndPos = new long[bean.getNSplitter()]; XzW7eO ,A  
} 5Yn{?r\#F  
hEWx.  
0~qf-x  
u0s'6=  
} m$,cH>E  
 WN$R[N  
{s,^b|I2#U  
public void run() #UBB lE#  
{ TF%3uH  
//获得文件长度 {x7=;-  
//分割文件 qw5&Y$((  
//实例FileSplitterFetch % Oz$_Xe  
//启动FileSplitterFetch线程 ^Wif!u/HM  
//等待子线程返回 ;*W=c   
try{ OI*ZVD)J  
if(bFirst) DCt\E/  
{ Jc`Rs"2  
nFileLength = getFileSize(); \Bt =bu>Z  
if(nFileLength == -1) gxI&f  
{ ]7v81G5E  
System.err.println("File Length is not known!"); Wgav>7!9  
} ax4*xxU  
else if(nFileLength == -2) 5/ tj  
{ /731.l  
System.err.println("File is not access!"); l6V%"Lo/)  
} IhUW=1& J  
else ,GP!fsK  
{ L'13BRu`  
for(int i=0;i<nStartPos.length;i++) iD.0J/  
{ Y 5Qb4Sa  
nStartPos = (long)(i*(nFileLength/nStartPos.length));  dhZ Zb  
} CdDH1[J  
for(int i=0;i<nEndPos.length-1;i++) ^eT@!N  
{ o>0O@NE  
nEndPos = nStartPos[i+1]; 1$);V,DK!  
} T_uNF8Bh  
nEndPos[nEndPos.length-1] = nFileLength; r|l53I 5  
} u/_Gq[Q,u  
} 2dXU0095  
`E{;85bDH  
anK[P'Y  
//启动子线程 (~=Qufy  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; C5>{Q:.`e'  
for(int i=0;i<nStartPos.length;i++) XI]OA7Zis  
{ Y_$^:LG  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), = vY]G5y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &1*4%N@'  
nStartPos,nEndPos,i); m &9)'o  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \P*PjG?R  
fileSplitterFetch.start(); P)Z/JHB  
} )!N2'Ld  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }PtI0mZ1  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iP2U]d~M  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Uy(vELB  
nEndPos = " + nFileLength); 6lN?)<uQ  
// fileSplitterFetch[nPos.length-1].start(); 8rGl&  
{`+bW"9  
A,3@j@bdy  
//等待子线程结束 9@( O\xr  
//int count = 0; 5tN%a>D%  
//是否结束while循环 Bh\ [ CY  
boolean breakWhile = false; BXT 80a\  
n"XdHW0  
]&&I|K_  
while(!bStop) 8o!  
{ (hpTJsZ  
write_nPos(); : [A?A4l  
Utility.sleep(500); |}M~ kJ)  
breakWhile = true; :5r:I[FFy  
-;l`hRW  
T^KCB\\<  
for(int i=0;i<nStartPos.length;i++) 2.^7?ok  
{ CbnR<W-j  
if(!fileSplitterFetch.bDownOver) 5JQd)[Im  
{ `K$:r4/[  
breakWhile = false; bq c;.4$  
break; /Lq;w'|I  
} Sja"(sJ  
} U,oD44  
if(breakWhile) bk/.<Rt  
break; +<'uw  
NFdJb\  
w;lx:j!Vp$  
//count++; O4lxeiRgC  
//if(count>4) {KW&wsI  
// siteStop(); 6$W-?  
} :`{9x%o;  
B$K7L'e+-  
nvU+XCx  
System.err.println("文件下载结束!"); Ytl:YzXCi  
} o@qN#Mg?>}  
catch(Exception e){e.printStackTrace ();} F@>w&A ~K  
} N2[, aU  
#gxRTx  
1.hOE>A%  
//获得文件长度 +9<,3IJe6  
public long getFileSize() ,2=UuW"K  
{ ,m #@%fa  
int nFileLength = -1; ;s}-X_O<  
try{ +W V@o'  
URL url = new URL(siteInfoBean.getSSiteURL()); Iu=pk@*O  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nG&w0de<>  
httpConnection.setRequestProperty("User-Agent","NetFox"); T+ &x{+gZ  
h1Ke$#$6  
I T*fjUY&  
int responseCode=httpConnection.getResponseCode(); N&R '$w  
if(responseCode>=400) , I[^3Fn  
{ 27h/6i3  
processErrorCode(responseCode); jK ?  
return -2; //-2 represent access is error [+ %p!T  
} a(Gk~vD;"  
wZ (uq?3S`  
H;7O\  
String sHeader; S+` !%hJ  
K9x*Sep  
d&GKfF  
for(int i=1;;i++)  y)N.LS  
{ #Z2>TN  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); DI $ mD{  
//Utility.log(in.readLine()); [8V(N2  
sHeader=httpConnection.getHeaderFieldKey(i); TE*>a5C|  
if(sHeader!=null) #Pe\Z/  
{ 9m<X-B&P  
if(sHeader.equals("Content-Length")) B`RW-14g  
{ t[H_6)  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |Fh`.iT%c  
break; (P]^8qc  
} n:}MULy;  
} [*mCa:^  
else rsIt~w  
break; "K4X:|Om"  
} x|~D(zo  
} 7|{%CckN  
catch(IOException e){e.printStackTrace ();} ByB0>G''.  
catch(Exception e){e.printStackTrace ();} mCEKEX  
T }8r;<P6  
p ] $  
Utility.log(nFileLength); W #JVUGYD  
Ggxrj'r  
%8z+R m,Ot  
return nFileLength; "6[Ax{cM  
} KweHY,  
OTy 4"%  
[nhLhl4S  
//保存下载信息(文件指针位置) O*+w_fox  
private void write_nPos() ?(`nBlWQ5  
{ 5sf fDEU]A  
try{ kBDe*K.V  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Poylq] F  
output.writeInt(nStartPos.length); D@YM}HXuj  
for(int i=0;i<nStartPos.length;i++) o/i5e=9[y  
{ 5 \.TZMB  
// output.writeLong(nPos); N2S!.H!Wz  
output.writeLong(fileSplitterFetch.nStartPos); $fU/9jTa  
output.writeLong(fileSplitterFetch.nEndPos); a*$1la'Uf  
} duiKFNYN  
output.close(); 'nmYB:&!  
} *}Ae9  
catch(IOException e){e.printStackTrace ();} +Fy- ~Mq  
catch(Exception e){e.printStackTrace ();} ]i_):@  
} <R]Wy}2-  
$F /p8AraK  
Z{R=h7P  
//读取保存的下载信息(文件指针位置) Do{*cSd  
private void read_nPos() tM?I()Y&P  
{ FdK R{dX}  
try{ wTJMq`sY_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |L~gNC  
int nCount = input.readInt(); w~FO:/  
nStartPos = new long[nCount]; 9N3oVHc?  
nEndPos = new long[nCount]; .Q6{$Y%l  
for(int i=0;i<nStartPos.length;i++) '!|E+P-  
{ ht[TMdV  
nStartPos = input.readLong(); ="[+6X  
nEndPos = input.readLong(); YM,D`c[pX  
} }O-%kl  
input.close(); fxf GJNR  
} 5G]#'tu  
catch(IOException e){e.printStackTrace ();} {(zL"g46  
catch(Exception e){e.printStackTrace ();} |SJ% _#=i  
} 94>7-d  
h.+,*9T\  
e\bF_ N2VA  
private void processErrorCode(int nErrorCode) })=c:h &  
{ s-YV_  
System.err.println("Error Code : " + nErrorCode); Lu$:,^ C  
} {t IoC;Y  
v:;C|uE|  
9#=IrlV4  
//停止文件下载 5x L,~"  
public void siteStop() x:D<Mu#  
{ `&&6-/  
bStop = true; neMe<jr  
for(int i=0;i<nStartPos.length;i++) .q& ]wu  
fileSplitterFetch.splitterStop(); )F9%^a(  
mrB hvp""  
[4 (A458H  
} R/KWl^oNj  
} I$P7%}  
//负责部分文件的抓取 w]}cB+C+l#  
**FileSplitterFetch.java JeSkNs|vB  
*/ u[% J#S  
package NetFox; ?[|4QzR  
3By>t!~Q  
"9Fv!*<-W  
import java.io.*; 0z2R`=)  
import java.net.*; E4fvYV_ra  
vXWESy  
, ?s k J  
public class FileSplitterFetch extends Thread { C&MqUj"]  
+Y%I0.?&5  
f>JzG,-  
String sURL; //File URL 0i1?S6]d-  
long nStartPos; //File Snippet Start Position XzRWY\x  
long nEndPos; //File Snippet End Position sC*E;7gT,  
int nThreadID; //Thread's ID [}g5Z=l  
boolean bDownOver = false; //Downing is over &cv /q$W4  
boolean bStop = false; //Stop identical N 7|W.(  
FileAccessI fileAccessI = null; //File Access interface "i5AAP?_]{  
kO\&mL& qD  
kTe<1^,m  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'bqf?3W  
{ ,Y/>*,J  
this.sURL = sURL; c\?/^xr'!}  
this.nStartPos = nStart; Mh@ylp+q  
this.nEndPos = nEnd; U},W/g-  
nThreadID = id; %li{VDb  
fileAccessI = new FileAccessI(sName,nStartPos);//定位  K`mxb}  
} !"qEB2r  
}t{^*(  
!7Q.w/|=  
public void run() 9bYHb'70  
{ Boz_*l|  
while(nStartPos < nEndPos && !bStop) 6(;[ov1  
{ p<.!::*%(  
OaVL NA^{  
\$++.%0  
try{ _rWXcK3cjr  
URL url = new URL(sURL); o0v m?CL#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _3?xIT  
httpConnection.setRequestProperty("User-Agent","NetFox"); :zTj"P>"I  
String sProperty = "bytes="+nStartPos+"-"; J'oz P^N  
httpConnection.setRequestProperty("RANGE",sProperty); I,q~*d  
Utility.log(sProperty); Gl\RAmdc  
m*WEge*$t  
p{_ O*bo  
InputStream input = httpConnection.getInputStream(); &5CeRx7%  
//logResponseHead(httpConnection); 2Uw}'J_N  
{ l~T~3/i  
1JY90l$ME  
byte[] b = new byte[1024]; t5[JN:an  
int nRead; cF6@.)  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (>% Vj  
{ )FiU1E  
nStartPos += fileAccessI.write(b,0,nRead); .St h  
//if(nThreadID == 1)   rs KE  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A^jm<~  
} |[t=.dK%  
0R{R=r]  
Z\yLzy#8  
Utility.log("Thread " + nThreadID + " is over!"); wH5O>4LO  
bDownOver = true; _34YH5  
//nPos = fileAccessI.write (b,0,nRead); #k]0[;1os  
} ojI"<Q~g  
catch(Exception e){e.printStackTrace ();} &~6O;}\  
} cnO4N UDv  
} HCZ%DBU96  
iONql7S @  
 y3$\ m  
//打印回应的头信息 ZI*A0_;L  
public void logResponseHead(HttpURLConnection con)  Z~:lfCK`  
{ lP &%5y;  
for(int i=1;;i++) Hw3 ES  
{ , 0ja_  
String header=con.getHeaderFieldKey(i); ?~9X:~6\  
if(header!=null) F>nrV  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3m9 E2R,  
Utility.log(header+" : "+con.getHeaderField(header)); B}bNl 7 ~  
else }Qu 7o  
break; :Gk~FRA|  
} |iThgq_\z  
} f\_Q+!^  
Xm+3`$<  
` R-np_  
public void splitterStop() Rla*hc~  
{ `t"Kq+  
bStop = true; &cejy>K  
} ?n~j2-[<  
6@36 1f[  
u01^ABn  
} jYx(  
7q=xW6  
|#,W3Ik(l  
/* )W#g@V)>  
**FileAccess.java 1e%Xyqb  
*//文件访问(定位,写) Vi~+C@96  
package NetFox; D*b|(Oi  
import java.io.*; '\qr=0aW  
UYLI>XSd  
%-1-J<<J q  
public class FileAccessI implements Serializable{ $VNn`0^gF  
v Cr$miZ  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /v<8x?=  
RandomAccessFile oSavedFile; IKj1{nZvDc  
long nPos; `2+52q<FO  
l0o_C#"<S  
k}7)pJNj  
public FileAccessI() throws IOException Qc/J"<Lx  
{ ?Cl"jcQ*  
this("",0); &?pAt30K:  
} z<XS"4l?W  
At:C4>HE@  
_JB3+0@  
public FileAccessI(String sName,long nPos) throws IOException &WS%sE{p_  
{ )8PL7P84  
oSavedFile = new RandomAccessFile(sName,"rw"); A>S2BL#=  
this.nPos = nPos; .w"O/6."  
oSavedFile.seek(nPos); s_Gp +-  
} .v!e=i}.  
XS@6jbLE  
j R:Fih-}  
public synchronized int write(byte[] b,int nStart,int nLen) <Z_`^~!  
{ CdjGYS  
int n = -1; =@ RVLml  
try{ Gd 9B  
oSavedFile.write(b,nStart,nLen); F*u;'K   
n = nLen; *O2j<3CHf  
} p5ihuV,   
catch(IOException e) 6=D;K.!  
{ DO; 2)ZQ%  
e.printStackTrace (); L x&ZWF$  
} iddT.   
-0Ek&"=Z^  
"a7d`l:  
return n; ^~$ o-IX  
} Qw+">  
D=$<E x^p  
f #14%?/  
} J!>oC_0]8  
fAi113q!  
XhiC'.B_  
/* kzT'  
**SiteInfoBean.java * G4;  
*/ 0v?,:]A0E  
package NetFox; ,v+SD\7|  
gf@Dy6<  
!ywc).]e  
public class SiteInfoBean { #SmWF|/  
|SmN.*&(9  
U;/ )V  
private String sSiteURL; //Site's URL @AFLFX]  
private String sFilePath; //Saved File's Path J^T66}r[f,  
private String sFileName; //Saved File's Name FdD'Hp+  
private int nSplitter; //Count of Splited Downloading File @2<J_Ja  
"Y+`U  
Yv)/DsSyL  
public SiteInfoBean() Et (prmH  
{//nSplitter的缺省值为5 P:+:Cm<  
//default value of nSplitter is 5 Syb:i(Y  
this("","","",5); jn'8F$GU  
} z&8#1'  
?.H*!u+9>  
j(rFORT  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 53c6dl  
{ gQ[4{+DSf  
sSiteURL= sURL; %WR  
sFilePath = sPath; C/JFg-r  
sFileName = sName; ]z,?{S  
this.nSplitter = nSpiltter; ScD9Ct*):C  
n9%rjS$  
-Y6JU  
} ME.LS2'n  
jB;+tDC!Co  
%A Fy{l  
public String getSSiteURL() R?(j#bk  
{ GUxhCoxb  
return sSiteURL; 6ZE] 7~X  
} TL5bX+  
#{(rOb6H)  
711 z-  
public void setSSiteURL(String value) Ni`qU(I'|  
{ 1/ HofiIa  
sSiteURL = value; Wd7*sa3T  
} )-mB^7uXGv  
8dv1#F|  
1/ a,7Hl  
public String getSFilePath() mEGMe@37  
{ .*Z]0~ &|  
return sFilePath; .IqS}Rh  
} A 6d+RAx  
*\/UT  
B?]^}r  
public void setSFilePath(String value) `?)i/jko"  
{ Y<B| e91C  
sFilePath = value; ^l9S5 {  
} <MYD`,$yu  
h(9K7  
?^hC|IR$  
public String getSFileName() ;tHF$1!J  
{ tP\Utl-0  
return sFileName; 5o,82 Kti  
} sG3%~  
{MHr]A}X\  
@M1U)JoQ  
public void setSFileName(String value) f-Sb:O!V  
{ 5b&'gd^d  
sFileName = value; 30<^0J.1  
} \Tc$P#  
S&a 44i  
g {00i  
public int getNSplitter() ;y"DEFs,u  
{ qU"+0t4  
return nSplitter; *StJ5c_kg2  
} M8h9i2  
wDsEx!\#  
fE(rDQI  
public void setNSplitter(int nCount) 'b-}KDP  
{ qZ4DO*%b3  
nSplitter = nCount; )T^hyi$  
} `8L7pbS%,Q  
} O@l`D`  
Z@1rs#  
3+)i23[4=\  
/*  z=!xN5  
**Utility.java >Zr`9$i  
*/ ?g!)[p`v  
package NetFox; q|S }5  
=4?m>v,re  
O:1YG$uKa  
public class Utility { B"G;"X  
k'm!|  
HxkhlNB  
public Utility() sp JB6n(  
{ #q%&,;4  
c(o8uWn  
oM< 9]jK}  
} IkD\YPL;  
.7oz  
//线程睡眠 Mq$e5&/  
public static void sleep(int nSecond) BsxQW`>^y  
{ f;QWlh"9  
try{ `S%p D.g,2  
Thread.sleep(nSecond); f@Db._ E  
} 'E6)6N  
catch(Exception e) myH#.$=A  
{ Ra.<D.  
e.printStackTrace (); v-OaH81&R  
} cd\0  
} ucyxvhH^-  
_Nw-|N.  
//日志 /KH3v!G0  
public static void log(String sMsg) syMB~g  
{ 8USF;k  
System.err.println(sMsg); !}U&%2<69  
} Fe8xOo6  
3rs=EMz:w  
>*EcX3  
public static void log(int sMsg) - v`;^X  
{ Bisht%]^  
System.err.println(sMsg); k{uc%6s  
} ^lf)9 `^U  
} s2q#D.f  
p5E|0p  
+[:}<^p?cG  
/* ZVViu4]?y  
**TestMethod.java ^ *RmT  
*/ 7u0!Q\  
package NetFox; evq *&.6\  
j`(o\Fd )  
N n+leM  
public class TestMethod { V*LpO 8=  
+tl&Jjdm  
}]kzj0m  
public TestMethod() {l! [{  
{ ///xx/weblogic60b2_win.exe H>k=V<  
try{ !DXKn\aQf  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jf@#&%AC9  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UfXqcyY(  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5yuR[ VU  
fileFetch.start(); njX!Ez  
} 6*Rz}RQ  
catch(Exception e){e.printStackTrace ();} Jv a&"}Cb  
[Cvo^cC  
hK3?m.> "g  
} \ c9EE-  
VQ2)qJ#l  
QXniWJJ  
public static void main(String[] args) c=h{^![$  
{ [{L4~(uU8  
new TestMethod(); !Hxx6/  
} P'R!" #  
} 7C F-?M!  
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