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http断点续传简单实现(java)

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/* Cvry8B  
**SiteFileFetch.java @SjISZw_  
*/ z\Hg@J&#  
package NetFox; 3yX^93  
import java.io.*; tg_xk+x  
import java.net.*; i882r=TE3  
<~@}r\  
LUc!a4i"fO  
public class SiteFileFetch extends Thread { { 0RwjPYp  
CBN,~wzP*  
,bzE`6  
SiteInfoBean siteInfoBean = null; //文件信息Bean 84j6.\,  
long[] nStartPos; //开始位置 pX8TzmIB0  
long[] nEndPos; //结束位置 H*51GxK  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 RZoSP(6  
long nFileLength; //文件长度 aZn]8jC%  
boolean bFirst = true; //是否第一次取文件 XD%@Y~>+  
boolean bStop = false; //停止标志 mM0VUSy  
File tmpFile; //文件下载的临时信息 S~()A*5  
DataOutputStream output; //输出到文件的输出流 wX Z"}uT<}  
G8z.JX-7g  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ? l/VCEZP  
public SiteFileFetch(SiteInfoBean bean) throws IOException lHerEv<ja  
{ O?L6Ues  
siteInfoBean = bean; L{1MyR7`I+  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); T&+*dyNxMK  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); !0!m |^c5  
if(tmpFile.exists ()) $ha,DlN  
{ 3V=wW{;x  
bFirst = false; >!sxX = <  
read_nPos(); h*d1G9%Q1  
} K G<. s<  
else =hFIH\x  
{ uE] HU  
nStartPos = new long[bean.getNSplitter()]; yhm6%  
nEndPos = new long[bean.getNSplitter()]; znnnqR0us  
} 0h/bC)z  
=\~<##sRJ  
u#!QIQW  
tf[)Q:|  
} +lC?Vpi^  
hhWIwR  
o|`[X '  
public void run() y/i{6P2`,D  
{  B0 E`C  
//获得文件长度 c(Ws3  
//分割文件 ?, B4  
//实例FileSplitterFetch OD[q u  
//启动FileSplitterFetch线程 3Gi^TXE]  
//等待子线程返回 =sZ58xA  
try{ )hG4,0hv&  
if(bFirst) 3fGL(5|_  
{ !aQb Kp  
nFileLength = getFileSize(); AS4mJ UU9  
if(nFileLength == -1) Lmsc ~~  
{ 8]h~jNku  
System.err.println("File Length is not known!"); 5tx!LGOK  
} @n,V2`"  
else if(nFileLength == -2) ~'1gX`o:  
{ &A}hx\_T  
System.err.println("File is not access!"); B']-4X{SGa  
} fk&>2[^&  
else 4j|IG/m  
{ y'L7o V?L9  
for(int i=0;i<nStartPos.length;i++) FQTAkkA_!  
{ q"(b}3  
nStartPos = (long)(i*(nFileLength/nStartPos.length));  )OHGg  
} U45kA\[bZ  
for(int i=0;i<nEndPos.length-1;i++) :'`y}'  
{ iq^F?$gFk  
nEndPos = nStartPos[i+1]; }TQa<;Q  
} Upw`|$1S  
nEndPos[nEndPos.length-1] = nFileLength; 0\zY?UUww  
} )DB\du   
} BTc }Kfae  
Oh# z zo  
|xawguJ  
//启动子线程 )_n=it$  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &cGa~#-u  
for(int i=0;i<nStartPos.length;i++) ?}RPn f  
{ +>3jMs~&  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [s4|+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tn{YIp   
nStartPos,nEndPos,i); :a/l9 m(  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bog3=Ig-  
fileSplitterFetch.start(); 3_bqDhVI5  
} hsB3zqotF  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `%A vn<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]A%]W^G  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fn#qcZv?  
nEndPos = " + nFileLength); CY~ S{w  
// fileSplitterFetch[nPos.length-1].start(); t"JE+G  
"7q!u,u  
GJ5R <f9I  
//等待子线程结束 s Poh\n  
//int count = 0; n&l(aRoyx  
//是否结束while循环 ?wP/l  
boolean breakWhile = false; `=V p 0tPI  
k?Kt*T  
/q,vQ[ R/  
while(!bStop) D%}rQ,*  
{ t!-\:8n  
write_nPos(); ?lE&o w  
Utility.sleep(500); Nj;5iy  
breakWhile = true; nuH=pIq6x  
6(=B`Z}a  
fUMjLA|*I<  
for(int i=0;i<nStartPos.length;i++) }W)b  
{ Jxf>!\:AZu  
if(!fileSplitterFetch.bDownOver) W_L*S4 ~  
{ w_h{6Kc<  
breakWhile = false; cgnMoBIc  
break; jB<B_"  
} Q5c3C &$6  
} !RP0W  
if(breakWhile) > ^=n|%  
break; ~R&rQJJeJ  
qj9[mBkP"  
U&i#cF   
//count++; {]bmecz  
//if(count>4) Y'{}L@"t  
// siteStop(); tD*k   
} )T6:@n^]h  
qt(4?_J  
uK] -m  
System.err.println("文件下载结束!"); 5dGfO:Dy_  
} <2d)4@B=  
catch(Exception e){e.printStackTrace ();} Pbd[gKX_  
} _@i-?Q  
*I!R0;HT  
yAAV,?:o[  
//获得文件长度 mqHcD8X  
public long getFileSize() wPEK5=\4Ob  
{ mv>0j<C91  
int nFileLength = -1; mPU}]1*p  
try{ Zs(BViTb|  
URL url = new URL(siteInfoBean.getSSiteURL()); IsmZEVuC  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hraR:l D  
httpConnection.setRequestProperty("User-Agent","NetFox"); eR4ib-nS  
OK)>QGl  
wz1nV}  
int responseCode=httpConnection.getResponseCode(); -oUGmV_  
if(responseCode>=400) #|K{txC   
{ tm/=Oc1p  
processErrorCode(responseCode); ,4S[<(T"  
return -2; //-2 represent access is error t>Ye*eR*`U  
} ?N<,;~  
Nyt*mbd5 {  
~j>yQ%[v  
String sHeader; {+zG.1o^  
V:#rY5X  
gg.]\#3g  
for(int i=1;;i++) & #JYh=#  
{ 118lb]  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \pk9i+t  
//Utility.log(in.readLine()); mKjTJzS  
sHeader=httpConnection.getHeaderFieldKey(i); O&MH5^I  
if(sHeader!=null) ;O1jf4y  
{ LofpBO6^  
if(sHeader.equals("Content-Length")) b}fC' h  
{ BYu(a  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >|, <9z`D  
break; P4HoKoj2`  
} 7m  ou  
} vp2w^/])u  
else 0Ix,c(%  
break; )u+O~Y95&i  
} k,$/l1D  
} |fywqQFq  
catch(IOException e){e.printStackTrace ();} qH0JZdk  
catch(Exception e){e.printStackTrace ();} %X's/;(Lx`  
sBYDo{0 1  
JN:L%If  
Utility.log(nFileLength); ^\g.iuE  
yH=<KYk  
 6/#+#T  
return nFileLength; '%4fQ%ID}  
} W**[:n+  
}-sh  
SOE-Kio=B  
//保存下载信息(文件指针位置) =xDxX#3  
private void write_nPos() %19~9Tw  
{  pdm(7^  
try{ ,}\LC;31,  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^SsdM#E  
output.writeInt(nStartPos.length); U# [T!E  
for(int i=0;i<nStartPos.length;i++) +pq) 7  
{ z6}p4  
// output.writeLong(nPos); p7 !y#  
output.writeLong(fileSplitterFetch.nStartPos); *#E_KW1RV  
output.writeLong(fileSplitterFetch.nEndPos);  [Rub  
} 4i.&geX A.  
output.close(); @54$IhhT~  
} x&^Xgi?  
catch(IOException e){e.printStackTrace ();} za}Kd^KeB  
catch(Exception e){e.printStackTrace ();} V )Oot|  
} V dvj*I  
 ]Tb?z&  
xI<B)6D;f  
//读取保存的下载信息(文件指针位置) &OZx!G^Z  
private void read_nPos() p[o]ouTcS  
{ ;zze.kb&F  
try{ ]KEE+o  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [L7s(Zs>  
int nCount = input.readInt(); tK[o"?2y  
nStartPos = new long[nCount]; lwfM>%%N  
nEndPos = new long[nCount]; x1Y/^ks@2  
for(int i=0;i<nStartPos.length;i++) @I|kY5'c  
{ 4[#)p}V  
nStartPos = input.readLong(); @67GVPcxl  
nEndPos = input.readLong(); n|?sNM<J3  
} OM^`P  
input.close(); =$+0p3[r  
} wl%ysM| x  
catch(IOException e){e.printStackTrace ();} m' S{P:TK  
catch(Exception e){e.printStackTrace ();} % >a /m.$  
} y`8U0TE3R  
Ym"^Ds}  
I L7kpH+y  
private void processErrorCode(int nErrorCode) Du +_dr^4  
{ "=+i~N#Sc  
System.err.println("Error Code : " + nErrorCode); K|\0jd)N  
} n^$Q^[:Z  
0[fBP\H"Wr  
@`+\v mfD  
//停止文件下载 !~RK2d  
public void siteStop() kCEo */,  
{ _VjaTw8iM  
bStop = true; #tpz74O  
for(int i=0;i<nStartPos.length;i++) @YRy)+  
fileSplitterFetch.splitterStop(); 3QKBuo  
a * CXg.i  
/2E Q:P  
} -O,:~a=*_  
} S&-F(#CF^  
//负责部分文件的抓取 N.+A-[7,W  
**FileSplitterFetch.java x^_c4,i)  
*/ KztQT9kY  
package NetFox; Sh5)36  
h5T~dGRlR  
0}`.Z03fy  
import java.io.*; [ _ `yy  
import java.net.*; !-n* ]C  
>);M\,1\I  
sw}^@0ua=  
public class FileSplitterFetch extends Thread { W`u @{Vb]  
8 %?MRRK  
-K$ugDi  
String sURL; //File URL pg!oi?Jn  
long nStartPos; //File Snippet Start Position 8dLmsk^  
long nEndPos; //File Snippet End Position k<j]b^jbz  
int nThreadID; //Thread's ID tS\Db'C7  
boolean bDownOver = false; //Downing is over A-.Wd7^~*  
boolean bStop = false; //Stop identical oiR9NB&<  
FileAccessI fileAccessI = null; //File Access interface (pM& eow}  
^fsC]9NS  
} ,}g](!m  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t~dK\>L  
{ x!W5'DO  
this.sURL = sURL; wj0_X;L  
this.nStartPos = nStart; LjEMs\P\  
this.nEndPos = nEnd; +:jv )4^O  
nThreadID = id; 6Y6t.j0vN.  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w;(=w N\  
} q&3(yhx  
_*g.U=u  
Z8/.I  
public void run() _<2{8>EVf  
{ AB0}6g^O  
while(nStartPos < nEndPos && !bStop) ~.J*_0~Ze  
{ 6vTnm4  
gaNe\  
_,v?rFLE  
try{ +t*I{X(  
URL url = new URL(sURL); uit.r^8l  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3?`TEw~'  
httpConnection.setRequestProperty("User-Agent","NetFox"); ~*\ *8U@7  
String sProperty = "bytes="+nStartPos+"-"; "Xwsu8~  
httpConnection.setRequestProperty("RANGE",sProperty); G(shZ=fq  
Utility.log(sProperty); 3G 5xIr6   
(RrC<5"  
o(> #}[N}  
InputStream input = httpConnection.getInputStream(); Z  eY *5m  
//logResponseHead(httpConnection); ki2 `gLK  
.X(qs1  
p/u  
byte[] b = new byte[1024]; eHGx00:  
int nRead; vA Z kT"  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DnhbMxh8o  
{ F\&^(EL  
nStartPos += fileAccessI.write(b,0,nRead); P.k>6T<U>  
//if(nThreadID == 1) Uc ,..  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U|.r -$|5P  
} [AIqKyIr  
9m_~Zs}Z  
nQ|($V1?W  
Utility.log("Thread " + nThreadID + " is over!"); Y`$\o  
bDownOver = true; 50A\Y)i_mZ  
//nPos = fileAccessI.write (b,0,nRead); I`jG  
} iqB%sIP  
catch(Exception e){e.printStackTrace ();} 2!CL8hG5:  
} @}wa Z?'  
} +>2.O2)%q  
  < /5  
wL]#]DiE  
//打印回应的头信息 snu?+*6  
public void logResponseHead(HttpURLConnection con) ,afO\oe>MG  
{ @ZJ }lED3  
for(int i=1;;i++) |=~mRqG  
{ lfd-!(tXD  
String header=con.getHeaderFieldKey(i); v$JW7CKA  
if(header!=null) v+trHdSBYE  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cUd>ah v  
Utility.log(header+" : "+con.getHeaderField(header)); jLO$[c`;  
else P|lDW|}D@  
break; G;pmR^  
} n) D  
} 3QVUWhJ  
+O8zVWr  
u#y)+A2&!  
public void splitterStop() T*C F5S  
{ 2ve<1+V_  
bStop = true; Y[>h |@  
} -`z%<)!Y  
>o`+j$j  
UH+#Nel+!  
} qkp0'f*}  
$T66%wX  
o /1+ }f  
/* =WZ9|e  
**FileAccess.java j` * bz-  
*//文件访问(定位,写) -k2|`t _  
package NetFox; ?|}qT05  
import java.io.*; 7h41E#  
9B83HV4J  
:9x]5;ma  
public class FileAccessI implements Serializable{ ;.=0""-IF  
jA~omX2A  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SdMLO6-  
RandomAccessFile oSavedFile; cH|J  
long nPos; 7i02M~*uS  
'^7UcgugB  
'"LaaTTs  
public FileAccessI() throws IOException hcYqiM@8>  
{ d1t_o2  
this("",0); xb9^WvV  
} 4f ~q$Sf]<  
l g ,%  
Y$)y:.2#  
public FileAccessI(String sName,long nPos) throws IOException aM#xy6:XG  
{ JX&%5sn(  
oSavedFile = new RandomAccessFile(sName,"rw"); v^p* l0r6:  
this.nPos = nPos; `C-8zA  
oSavedFile.seek(nPos); :=!6w  
} q;f L@L@-  
'gD./|Z0  
[]yIz1P=j  
public synchronized int write(byte[] b,int nStart,int nLen) 28+{  
{ `fJ;4$4  
int n = -1; +<V$G/"  
try{ BNr%Q:Q  
oSavedFile.write(b,nStart,nLen); 2VX9FDrnk  
n = nLen; 60e{]}Z  
} DR]oK_  
catch(IOException e) d$E>bo-\   
{ 0a@tPskV  
e.printStackTrace ();  z.2UZ%:  
} rxJl;!7G  
S+mBVk"-~S  
I1dOMu9  
return n; Q[H4l({E  
} s,/C^E  
;<+Z}d/g9  
4R8Qn^  
} --c)!Vxzx  
LtKR15h,  
*J': U>p  
/* gA1j'!\6l9  
**SiteInfoBean.java \S?-[v*{  
*/ 8 K)GH:a  
package NetFox; 6e5A8e8"]  
w_~tY*IwB  
=1)9>=}  
public class SiteInfoBean { oz|+{b}%  
}"%mP 4]&  
< %<nh`D  
private String sSiteURL; //Site's URL ~% `hh9]  
private String sFilePath; //Saved File's Path 9ku|w#%I  
private String sFileName; //Saved File's Name vtK.7AF  
private int nSplitter; //Count of Splited Downloading File V;)+v#4{  
L7xiq{t`Y  
k{|> !(Ax  
public SiteInfoBean() h:FN&E c}  
{//nSplitter的缺省值为5 R]>0A3P  
//default value of nSplitter is 5 d:cOdm>,  
this("","","",5); GlJOb|WOX  
} Dd, &a  
XI`s M~'  
B_8JwMJu3  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2'Kh>c2  
{ jSdC1,wR  
sSiteURL= sURL; v9f%IE4fX  
sFilePath = sPath; q8GCO\(  
sFileName = sName; 9 *v14c%  
this.nSplitter = nSpiltter; 3{ea~G)[9  
pwV~[+SS_  
N1" bH~  
} Zqb*-1Qw"*  
x{/-&`F  
bH!_0+$P  
public String getSSiteURL() -z%->OUu  
{ _nSEp >]L  
return sSiteURL; tTh4L8fO  
} G3h"Eo?>g  
;Eh"]V,e  
6P)DM  
public void setSSiteURL(String value) Xe(]4Ux  
{ p&D7&Sb[  
sSiteURL = value; "~Zdv}^xS  
} :)h4SD8Y  
:z6?  
MM( ,D& Z  
public String getSFilePath() x'SIHV4M@Q  
{ GB,ub*|  
return sFilePath; {\|XuCF#  
} a>+m_]*JZ  
LLoV]~dvUu  
*z0 R f;  
public void setSFilePath(String value) JOs kf(  
{ ,wy;7T>ODd  
sFilePath = value; 'Zqt~5=5  
} u#Bj#y!  
i+lq:St  
@gQ?cU7  
public String getSFileName() gADqIPu]  
{ ,mz7!c9H^a  
return sFileName; z80*Ylx  
} x@:98P  
kV3LFPf>0  
;Rm';IW$  
public void setSFileName(String value) p:ZQ*Ue  
{ llCE}Vdh  
sFileName = value; -w'g0/fD  
} G/w@2lYx  
c;=St1eoz  
^PMA"!n8  
public int getNSplitter() {96NtR0Z  
{ [FBc&HN  
return nSplitter; ^E%NYq_2l<  
} F>E_d<m  
*Tmqs@L  
E;"VI2F  
public void setNSplitter(int nCount) %f(4jQ0I  
{ aD~S~L!  
nSplitter = nCount; B =DV!oUg  
} {yi!vw  
} r\y\]AmF  
rERtOgi  
e"Z,!Q^-L  
/* jT;'T$  
**Utility.java v~p?YYOm<  
*/ U<'$ \ P  
package NetFox; jASK!3pY  
DvA#zX[  
-ilhC Y@M  
public class Utility { NCm=l  
sr~VvciIy  
-'i[/{  
public Utility() Aiqb*v$  
{ ](IOn:MuDE  
9AD0|,g  
nYj7r* e[  
} jank<Q&w  
&d"s cM5  
//线程睡眠 )F0Q2P1I  
public static void sleep(int nSecond) T{BGg  
{ paxZlA o  
try{ /4+*!X  
Thread.sleep(nSecond); @Z96902<t  
} swhtlc@@  
catch(Exception e) W5&KmA  
{ 1+tPd7U  
e.printStackTrace (); -1R7 8(1  
} zEeix,IU  
} J!'IkC$>  
MOIVt) ZY  
//日志 pf3-  
public static void log(String sMsg) gER(&L4[  
{  GU xhn  
System.err.println(sMsg); 73!])!SVI  
} s1T}hp  
fl*49-d  
L-e6^%eU  
public static void log(int sMsg) ay=f1<a  
{ %@;xbKj  
System.err.println(sMsg); y<y9'tx  
} P{8<U8E  
}  <XnxAA  
2{L[D9c/6  
I>>X-}  
/* N&u(9Fxn  
**TestMethod.java "%=K_WJ?  
*/ XJ3aaMh"  
package NetFox; "04:1J`  
1sfs!b&E  
~@iYP/=/Q  
public class TestMethod { Uz7V2r%]  
4Y@q.QP  
c5{3  
public TestMethod() Zg >!5{T  
{ ///xx/weblogic60b2_win.exe TI3@/SB>  
try{ "o<&3c4  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8;Df/ %  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rVnolA*%  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $H7T|`WI.,  
fileFetch.start(); bw[K^/  
} "=9)|{=m  
catch(Exception e){e.printStackTrace ();} *&W1|Qkg_  
~"vRH  
Fi#b0S  
} q.p.y0  
RSf*[2  
})ic@ Mmd$  
public static void main(String[] args) P Z+Rz1x  
{ .BZ3>]F3<  
new TestMethod(); $C6O<A  
} 1=Q3WMT  
} M{U7yE6*j*  
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