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http断点续传简单实现(java)

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/* E7.2T^o;M  
**SiteFileFetch.java r[BVvX/,F  
*/ l8I /0`_  
package NetFox;  swK-/$#  
import java.io.*; F({HP)9b  
import java.net.*; Fh`~`eog  
]^lw*724'>  
}% `.h"  
public class SiteFileFetch extends Thread { #~7ip\Uf[  
zG ^$"f2  
P(H8[,  
SiteInfoBean siteInfoBean = null; //文件信息Bean PcA2/!a  
long[] nStartPos; //开始位置 *~t6(v?  
long[] nEndPos; //结束位置 v.pBX<  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 tn Pv70m  
long nFileLength; //文件长度 j6Yy6X]  
boolean bFirst = true; //是否第一次取文件 t=Xv;=daB  
boolean bStop = false; //停止标志 SZ,YS 4M  
File tmpFile; //文件下载的临时信息 |y0(Q V  
DataOutputStream output; //输出到文件的输出流 ;$smH=I  
d8[J@M53|T  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) L1cI`9  
public SiteFileFetch(SiteInfoBean bean) throws IOException \P.I)n`8 y  
{ X~lVVBO  
siteInfoBean = bean; h|,:e;>}  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 6LalW5I  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); BI3@|,._N  
if(tmpFile.exists ()) RloK,bg  
{ n?- })  
bFirst = false; {so `/EWa  
read_nPos(); &Xf^Iu  
} 3BtaH#ZY  
else bn!HUM,  
{ /H8g(  
nStartPos = new long[bean.getNSplitter()]; H."EUcE{  
nEndPos = new long[bean.getNSplitter()]; ~:Ll&29i  
} SKkUU^\#R`  
nEJY5Bz$  
kQEy#JQmB  
tasUZ#\6  
} B"!l2  
a-=8xs'  
^pQCNKLBY  
public void run() @\f^0^G  
{ S/9DtXQ  
//获得文件长度 ,n3a gkPO>  
//分割文件 \l9qt5rS  
//实例FileSplitterFetch Dey<OE&  
//启动FileSplitterFetch线程 G+X Sfr  
//等待子线程返回 xlA$:M&  
try{ uTKD 4yig  
if(bFirst) PE5R7)~A  
{ +RyjF~  
nFileLength = getFileSize(); VXR>]HUF  
if(nFileLength == -1) "#{4d),r  
{ CF?1R  
System.err.println("File Length is not known!"); (O.d>  
} v7iuL6jl  
else if(nFileLength == -2) j)<IRD^  
{ >zXsNeGQR  
System.err.println("File is not access!"); &6ZD136  
} e[&L9U6GW-  
else KG|n  
{ *X+79vG:  
for(int i=0;i<nStartPos.length;i++) }a/x._[s  
{ J&.{7YF  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); L.S;J[a;  
} " @v <Bk  
for(int i=0;i<nEndPos.length-1;i++) p<,*3huj  
{ /5Oa,NS7  
nEndPos = nStartPos[i+1]; 1*9U1\z  
} }]lr>"~y}  
nEndPos[nEndPos.length-1] = nFileLength; d$ x"/A]<  
} gm igsXQ  
} Z -W(l<  
>[*8I\*@n  
ykV 5  
//启动子线程 05b_)&4R  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A v2 08}Y  
for(int i=0;i<nStartPos.length;i++) "1 L$|  
{ 0n;< ge&~R  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;"dV"W  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]G5 w6&d  
nStartPos,nEndPos,i); h*w%jdQ6  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  %oZ6l*  
fileSplitterFetch.start(); 925|bX6I  
} }BZ"S-hZ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KKiE@_z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E4|jOz^j4\  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w5Ay)lz  
nEndPos = " + nFileLength); BD_Iz A<wK  
// fileSplitterFetch[nPos.length-1].start(); .Le?T&_  
WtG~('g>&  
@+Si?8\  
//等待子线程结束 $\]&rZVi  
//int count = 0; El.hu%#n*G  
//是否结束while循环 C8Qa$._  
boolean breakWhile = false; ]rWgSID  
S|7!{}  
zgNc4B  
while(!bStop) zNxW'?0Z?  
{ c:<005\Bg  
write_nPos(); kEOS{C%6R  
Utility.sleep(500); "B3N* R(["  
breakWhile = true; JBE!j-F  
mS(fgq6  
UNom-  
for(int i=0;i<nStartPos.length;i++) r:f[mk"-"A  
{ S- pV_Ff  
if(!fileSplitterFetch.bDownOver) K/i*w<aPb7  
{ `6lr4Kk @R  
breakWhile = false; N G "C&v  
break; r'^Hg/Jzt  
} 6kpg+{;  
} * w?N{.  
if(breakWhile) kYG/@7f/  
break; jQ2Ot<  
gtk7)Uh  
e1%/26\  
//count++; 5*lT.  
//if(count>4) [N7{WSZ&  
// siteStop(); CE#gfP  
} F`gi_; c  
VH9dleZ  
/{+y2.{j  
System.err.println("文件下载结束!"); D8Ykg >B;&  
} 95 ;x=ju  
catch(Exception e){e.printStackTrace ();} B@&4i?yJ  
} M?Dfu .t  
DI:]GED" =  
QZ6D7t Uc8  
//获得文件长度 '*5i)^  
public long getFileSize() _F>CBG  
{ \fG#7_wt  
int nFileLength = -1; =]6%G7T  
try{ +x0!*3q  
URL url = new URL(siteInfoBean.getSSiteURL()); L^}_~PO N5  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iII=;:p  
httpConnection.setRequestProperty("User-Agent","NetFox"); )wC?T  
}&cu/o4  
(gP)%  
int responseCode=httpConnection.getResponseCode(); ^ DaBz\  
if(responseCode>=400) kW;+|qs^  
{ QRHu 3w  
processErrorCode(responseCode); NW]Lj >0Y  
return -2; //-2 represent access is error '[AlhBX  
} w>pq+og&  
\-h%O jf4  
XGYbnZ~   
String sHeader; RL!Oi|8  
)J2mM  
 gbF+WE  
for(int i=1;;i++) ?}wk.gt>  
{ #M9~L[nF S  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "I3@m%qv  
//Utility.log(in.readLine()); ?zh9d%R  
sHeader=httpConnection.getHeaderFieldKey(i); A\4D79>x  
if(sHeader!=null) $xzAv{  
{ #.rdQ,)<  
if(sHeader.equals("Content-Length")) ojaws+(& y  
{ >_[ 9t  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yA)/Q Yge  
break; \pPY37l  
} 01wX`"I  
} EMY/~bQW  
else idLWe9gC  
break; 6 Q%jA7  
} fObg3S92  
} v- 2:(I V  
catch(IOException e){e.printStackTrace ();} nV"~-On  
catch(Exception e){e.printStackTrace ();} e>6y%v;  
((H^2KJn  
t<#TJ>Le  
Utility.log(nFileLength); th  
O#ai)e_uQk  
kVkU)hqR  
return nFileLength; xN5)   
} n&$j0k  
6HT ;#Znn  
.YhA@8nc~l  
//保存下载信息(文件指针位置) CDsSrKhx  
private void write_nPos() Jl( &!?j  
{ :ci5r;^  
try{ \hTm)-FP  
output = new DataOutputStream(new FileOutputStream(tmpFile)); m8A#~i .  
output.writeInt(nStartPos.length); 6eLR2  
for(int i=0;i<nStartPos.length;i++) % Qmn-uZ  
{ ;D3C >7y  
// output.writeLong(nPos); gwLf'  
output.writeLong(fileSplitterFetch.nStartPos); YmL06<Mh  
output.writeLong(fileSplitterFetch.nEndPos); NP0\i1P>.?  
} Px4) >/ z,  
output.close(); i6^twK)j  
} }JF13beU  
catch(IOException e){e.printStackTrace ();} U;YC}r  
catch(Exception e){e.printStackTrace ();} [$mHv,~  
} {#ZlM  
*:Y%HAy*  
RSfQNc9Z  
//读取保存的下载信息(文件指针位置) <^VJy5>  
private void read_nPos() [)H&'5 +F  
{ ,|3MG",@@h  
try{ D9<!mH  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N4v~;;@(  
int nCount = input.readInt(); Y\D!/T  
nStartPos = new long[nCount]; n`#tKwWHYx  
nEndPos = new long[nCount]; H=<S 9M  
for(int i=0;i<nStartPos.length;i++) ,vr? 2k  
{ HJ9Kz^TnC  
nStartPos = input.readLong(); t_o['F  
nEndPos = input.readLong(); m4**~xfC  
} ~5NXd)2+Ks  
input.close(); Zq^At+8+  
} +[M6X} TQ  
catch(IOException e){e.printStackTrace ();} .!Oo|m`V@  
catch(Exception e){e.printStackTrace ();} R cAwrsd  
} h?AS{`.1  
UbXh,QEG*  
{&cJDqz5=  
private void processErrorCode(int nErrorCode) ^NRl//  
{ &q3"g*q  
System.err.println("Error Code : " + nErrorCode); FEW14 U'O  
} '9laa=H%8  
fa-IhB1!K  
qB~rQPa  
//停止文件下载 \z>fb%YW  
public void siteStop() `nUXDmdwzO  
{ ),0g~'I~D  
bStop = true; v_BcTzQ0S  
for(int i=0;i<nStartPos.length;i++) @:j}Jmg  
fileSplitterFetch.splitterStop(); TITKj?*o  
*F+KqZ.2  
lG9bLiFY  
} eX?OYDDC0j  
} Tl%`P_J)-S  
//负责部分文件的抓取 02f~En}>6  
**FileSplitterFetch.java 4QH3fTv   
*/ ;!=G   
package NetFox; ,$@bE  
.7Dtm<K#  
lsJSYJG&  
import java.io.*; ojafy}  
import java.net.*; A0/"&Ag]  
lAS#874dE  
9Z|jxy  
public class FileSplitterFetch extends Thread { rx'RSo#1O  
!`k1:@NZ  
- \ 5v^l  
String sURL; //File URL O@tU.5*$5  
long nStartPos; //File Snippet Start Position RM]\+BK  
long nEndPos; //File Snippet End Position fFMlDg[];  
int nThreadID; //Thread's ID 2L:_rR#w  
boolean bDownOver = false; //Downing is over `[z<4"Os   
boolean bStop = false; //Stop identical KT_!d*  
FileAccessI fileAccessI = null; //File Access interface SOs:]U-T3  
v]'ztFA  
/'Ass(=6  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7TgOK   
{ } K7#Q  
this.sURL = sURL; GD&uQ`Y5  
this.nStartPos = nStart; .!Qki@  
this.nEndPos = nEnd; Za/-i"U  
nThreadID = id; /@wg>&L]  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bENdMH";  
} bZ?v-fn\D,  
+M./@U*g  
_ q(ko/T  
public void run() j:^#rFD4?  
{ 9`T)@Uj2n  
while(nStartPos < nEndPos && !bStop) bbtGXfI+SB  
{ 18)'c?^.  
+dWDxguE{w  
Y4OPEo5o  
try{ e{h<g>7  
URL url = new URL(sURL); [/PR\'|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ")_|69 VX  
httpConnection.setRequestProperty("User-Agent","NetFox");  Hu^1[#  
String sProperty = "bytes="+nStartPos+"-"; ls?~+\Jb  
httpConnection.setRequestProperty("RANGE",sProperty); 3oBtP<yG.  
Utility.log(sProperty); $'0u|Xy`  
:I"2V  
I.WvLLK2  
InputStream input = httpConnection.getInputStream(); XQrF4l  
//logResponseHead(httpConnection); v V'EZ ?  
ob+b<HFv  
aB*Bz]5;E  
byte[] b = new byte[1024]; Htay-PB }  
int nRead; ynmWW^dg  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <>n0arAn  
{ >Y&N8PHD  
nStartPos += fileAccessI.write(b,0,nRead); dah[:rP,n{  
//if(nThreadID == 1) b1?#81  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); teOe#*  
} s6ZuM/Q  
QgrpBG  
\n"{qfn`r  
Utility.log("Thread " + nThreadID + " is over!"); j>*S5y.{  
bDownOver = true; 3RiWZN  
//nPos = fileAccessI.write (b,0,nRead); iMt:9|yF}8  
} pe0F0Ruy  
catch(Exception e){e.printStackTrace ();} v&Ii^?CvO  
} f& 0M*o,)  
} qsF<!'m7`  
wJg1Y0nh  
)) Zf|86N  
//打印回应的头信息 >lmi@UN|k  
public void logResponseHead(HttpURLConnection con) +ylTGSZS  
{ PUz*!9HC  
for(int i=1;;i++) ZufR {^W  
{ OGBHos  
String header=con.getHeaderFieldKey(i); "HX<,l8f%  
if(header!=null) 3ovWwZ8&  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ];}Wfl  
Utility.log(header+" : "+con.getHeaderField(header)); Q;MT"=RW  
else t$ +?6E  
break; @M<|:Z %.@  
} 7@C<oy_bb  
} x9NEFtqjm  
".f ;+wH  
xpNH?#&  
public void splitterStop() u=Fv 2  
{ +~St !QV%  
bStop = true; 2:*w~|6>}5  
} i}b${n o  
r~[Ia!U?  
f'8kish  
} 6f;fx}y  
3yANv?$a  
-1Jg?cPz k  
/* +O'3|M  
**FileAccess.java {Z{75}  
*//文件访问(定位,写) TH)"wNa  
package NetFox; hrmut*<|  
import java.io.*; yhlFFbU  
OL5v).Bb  
wWgWWXGT}  
public class FileAccessI implements Serializable{ 9K/HO!z  
m2 -Sx  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s.EI`*xylY  
RandomAccessFile oSavedFile; k[0-CB  
long nPos; (VS5V31"  
?xK8#  
;g8R4!J  
public FileAccessI() throws IOException so^lb?g  
{ U!T~!C^  
this("",0); WJ)z6m]  
} w'L\?pI  
mrTlXXz  
A+HF@Uw}^  
public FileAccessI(String sName,long nPos) throws IOException \ Fl+\?~D  
{ h"lX 4  
oSavedFile = new RandomAccessFile(sName,"rw"); :WQ^j!9'  
this.nPos = nPos; ko1J094Y%  
oSavedFile.seek(nPos);  0,r}o  
} tzZ63@cm  
^F>cp ,x  
z25lZI" X`  
public synchronized int write(byte[] b,int nStart,int nLen) {-ZFp  
{ CPgCjtY  
int n = -1; Yaj0;Lo[wt  
try{ INUG*JC6  
oSavedFile.write(b,nStart,nLen); =b38(\  
n = nLen; U0=]  
} "ZHW2l Mf  
catch(IOException e) Cv }Qwy  
{ "~`I::'c  
e.printStackTrace (); Z.d 7U~_  
} FE" y\2}  
- *F(7$  
Kqun^"Df  
return n;  R=.4  
} S2n39 3  
yPM3a7-Bm  
]FD'5p{  
} t'9*R7=  
u?>B)PW  
N03G>fZ  
/* R,)}>X|<  
**SiteInfoBean.java Xm+8  
*/ 'iy*^A `Y  
package NetFox; 0$_oT;{8  
YiYV>gaf"H  
*ohL&'y  
public class SiteInfoBean { 5pU2|Bk /  
5'0xz.)!  
+$X#q8j06  
private String sSiteURL; //Site's URL !)  S ?m  
private String sFilePath; //Saved File's Path ~n[d4qV&  
private String sFileName; //Saved File's Name CQZgMY1{  
private int nSplitter; //Count of Splited Downloading File Mmj;'iYOwF  
Y^36>1.:  
K6y :mJYp\  
public SiteInfoBean() Jwj%_<  
{//nSplitter的缺省值为5 np%\&CVhN  
//default value of nSplitter is 5 y+!+ D[x  
this("","","",5); JBZUv  
} *J$=.fF1  
$=5=NuX  
BQBeo&n6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F&])P- !3  
{ c<uN"/gi*  
sSiteURL= sURL; bB }$'  
sFilePath = sPath; lAzj N~V  
sFileName = sName; h tx;8:  
this.nSplitter = nSpiltter; YWMGB#=  
,REJt  
V<D.sd<  
} / y A7%2  
!E,A7s  
KQ `qpX^d  
public String getSSiteURL() _8Z_`@0  
{ j>]nK~[ka  
return sSiteURL; kgy:Q'  
} 4VHqBQ4  
PGYXhwOI  
.w> 4  
public void setSSiteURL(String value) n"+[ :w4  
{ /R~1Zj2&  
sSiteURL = value; k4,BNJt'Z  
} ?6(I V]  
UJ0<%^f  
-6Oz^  
public String getSFilePath() 6&DX] [G  
{ i O/K nH  
return sFilePath; 4Y,R-+f  
} {n/uh0>f*  
; l&4V  
I/M_p^  
public void setSFilePath(String value) 4 SHU  
{ Rop'e8Q  
sFilePath = value; ZIPl7tTw  
} rSxxH]-  
{g2@6ct  
#?*WPq  
public String getSFileName() pAb.c  
{ NM]s8cK_  
return sFileName; _$wmI/_J M  
} WuPH'4b 5  
?6L&WB  
rEHkw '  
public void setSFileName(String value) ^zEwA  
{ F^N82  
sFileName = value; ]Pry>N3G5  
} h@:TpE+N  
Ct2j ZqCDo  
{88gW\GL  
public int getNSplitter() UbEb&9}  
{ CPVjmRUF|  
return nSplitter; lY~4'8^  
} HS{(v;  
*+TH#EL2  
} X^|$  
public void setNSplitter(int nCount) "jTKSgv+q5  
{ nL$x|}XAcj  
nSplitter = nCount; :ml2.vP  
} \Y|~2Ls8tu  
} 'eo KZX+  
i<H wTmm$  
.!1S[  
/* G2]4n T  
**Utility.java Z|_K6v/c  
*/ GwG4LIp  
package NetFox; Eo\UAc  
'" X_B0k  
!(n4|Wd  
public class Utility { V[}4L| ad  
>N;F8v  
Ypeiy `.  
public Utility() }tH[[4tw,  
{ nSF``pp+  
uch>AuF:  
p8kr/uMP ;  
} R)M_|ca  
f6_];]yP  
//线程睡眠 Xcrk;!IB?  
public static void sleep(int nSecond) pM{nh00[  
{ f;&]:2.j  
try{ bHht d_}  
Thread.sleep(nSecond); V?P,&c?84  
} ~by]xE1Eg  
catch(Exception e) Cw~RJ^a_  
{ 1iX)d)(b  
e.printStackTrace (); PzV@umC1#f  
} B|C/ Rk6?  
} +$$$  
P y>{t4;S  
//日志 `+zWu 55;  
public static void log(String sMsg) >iOzl wmG  
{ /0W9g  
System.err.println(sMsg); y kW [B  
} *?z0$Kz<,[  
qS/V"|G(  
4B4Z])$3  
public static void log(int sMsg) s0*0 'f  
{ L4b:F0  
System.err.println(sMsg); ) c/% NiN  
} < -uc."6\  
} i.xXb [M+  
$xOI 1|d   
9%iUG(DC  
/* `C_jP|[e  
**TestMethod.java BnCKSg7V  
*/ Tx 1 vL  
package NetFox; ?E9DXg  
&O)&k  
?9HhG?_x  
public class TestMethod { RP 2_l$  
ari7iF ~j  
^A][)*SZ  
public TestMethod() YXU|h  
{ ///xx/weblogic60b2_win.exe $B#6tk~u  
try{ b1gaj"]  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Fhv2V,nZ<  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T1` |~Z?g-  
SiteFileFetch fileFetch = new SiteFileFetch(bean); C@Nv;;AlU  
fileFetch.start(); +&X%<S W  
} -w;(cE  
catch(Exception e){e.printStackTrace ();} 2>]a)  
T/c<23i  
!Oj)B1gc6&  
} K. %U  
'`|A I:L  
FVB;\'/  
public static void main(String[] args) \eGKkSy  
{ @)>D))+  
new TestMethod(); P_gYz!  
} zf.- I  
} H{?9CxYa  
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