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http断点续传简单实现(java)

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/* SUCU P<G  
**SiteFileFetch.java 5/><$06rq  
*/ sfT+i;p  
package NetFox; 0rSIfYZa  
import java.io.*; +>^7vq-\'  
import java.net.*; 5X.ebd;PT  
qeL pXe0c  
B0}~G(t(  
public class SiteFileFetch extends Thread { jjs&`Fy,  
b}!3;:iD  
rM}0%J'  
SiteInfoBean siteInfoBean = null; //文件信息Bean S:Q! "U  
long[] nStartPos; //开始位置 ` m@U!X  
long[] nEndPos; //结束位置 MZv]s  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 UM%o\BiO  
long nFileLength; //文件长度 3k$[r$+"  
boolean bFirst = true; //是否第一次取文件 0X|_^"!  
boolean bStop = false; //停止标志 GV|9H]_,I  
File tmpFile; //文件下载的临时信息 _o6G6e,  
DataOutputStream output; //输出到文件的输出流 ^ZeJ[t&!#  
VaZn{z  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 8;P2A\ X  
public SiteFileFetch(SiteInfoBean bean) throws IOException i%Z2wP.o  
{ NUJ~YWO;  
siteInfoBean = bean; Wl"0m1G  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); t G.(flW,  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ITJ q  
if(tmpFile.exists ()) jn%kG ~]'Q  
{ k_|^kdWJ  
bFirst = false; -cF'2Sfr  
read_nPos(); W_M'.1 t  
} zoDZZ%{  
else .lG5=Th!  
{ PaB!,<A  
nStartPos = new long[bean.getNSplitter()]; *4Fr&^M\  
nEndPos = new long[bean.getNSplitter()]; SkNre$>t{  
} j=+"Qz/hr_  
1^J`1  
5`[n8mU  
;oO v/3  
} }u{gR:lZ  
N^0uit  
i8X`HbmN  
public void run() CG]Sj*SA~  
{ {i~8 :  
//获得文件长度 )vB2!H/  
//分割文件 x|64l`Vp(:  
//实例FileSplitterFetch vEe NW  
//启动FileSplitterFetch线程 V}w;Y?] J  
//等待子线程返回 a T  l c  
try{ t%1^Li  
if(bFirst) t=euE{c  
{ K r`]_m  
nFileLength = getFileSize(); 4pU>x$3$  
if(nFileLength == -1) D<{{ :7n  
{ !G5a*8]  
System.err.println("File Length is not known!"); ~|Y>:M+0Z  
} &:B<Q$g#  
else if(nFileLength == -2) B#%; Qc  
{ ._:nw=Y0<}  
System.err.println("File is not access!"); g&/p*c_  
} f3*?MXxb16  
else l7[7_iB&E  
{ .3pbuU  
for(int i=0;i<nStartPos.length;i++) W1aa:hEf  
{ C.  MoKa3  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); C&\5'[*  
} g|<Sfp+;+  
for(int i=0;i<nEndPos.length-1;i++) H( ^bC5'  
{ ^cvl:HOog  
nEndPos = nStartPos[i+1]; Br>Fpe$q4  
} u~zs* qp  
nEndPos[nEndPos.length-1] = nFileLength; {Z;t ^:s#  
} "%2xR[NF  
} ~vdkFc(8B  
W{cY6@  
`Kl`VP=c  
//启动子线程 }A$WO {2  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s Wjy6;  
for(int i=0;i<nStartPos.length;i++) ({}(qm  
{ vdoZ&Tu  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )wXuwdc[  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C R<`ZNuWz  
nStartPos,nEndPos,i); v{x{=M]  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -]G(ms;}/Y  
fileSplitterFetch.start(); HHk)ZfWRo  
} Y]aW)u  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6X g]/FD  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }*U[>Z-eO  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2Nc>6  
nEndPos = " + nFileLength); @{ ;XZb^  
// fileSplitterFetch[nPos.length-1].start(); :B *}^g  
OU DcY@x~  
^ ?hA@{T/1  
//等待子线程结束 N^?9ZO   
//int count = 0; Wk;5/  
//是否结束while循环 iP~,n8W  
boolean breakWhile = false; *y[PNqyd  
%T`U^ Pnr  
s0UFym 8  
while(!bStop) qd@&59zSh  
{ )4Q?aMm  
write_nPos(); |w}w.%  
Utility.sleep(500); .] 4W!])9  
breakWhile = true; em@EDMvI  
/G{_7cb  
JwnAW}=  
for(int i=0;i<nStartPos.length;i++) 3M*Bwt;F_  
{ }w-wSkl1  
if(!fileSplitterFetch.bDownOver) G1T^a>tj4  
{ Q'apG)0I  
breakWhile = false; 8 }'|]JK  
break; 3. WF}8  
} =H7xD"'%R  
} `rY2up#%  
if(breakWhile) g8;D/  
break; mo]KCi  
}$su4A@0  
y k161\  
//count++; )(Iy<Y?#  
//if(count>4) Tm]nEl)_  
// siteStop(); yTM{|D]$(  
} F-Z%6O,2  
?^Hf Np9  
a.F Al@Br  
System.err.println("文件下载结束!"); )8gGv  
} sE(HZR1  
catch(Exception e){e.printStackTrace ();} 8Ad606  
} A!W0S  
d?idTcgs  
m"tOe?  
//获得文件长度 >v;8~pgO  
public long getFileSize() CCijf]+  
{ JM$.O;y -  
int nFileLength = -1; nHFrG =o,  
try{ R_P}~l  
URL url = new URL(siteInfoBean.getSSiteURL()); &Jc_Fc(M  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -XoPia2  
httpConnection.setRequestProperty("User-Agent","NetFox"); ytEC   
6" T['6:j  
dP$GThGl  
int responseCode=httpConnection.getResponseCode(); UO`;&e-DB  
if(responseCode>=400) AtS;IRN@  
{ z:Sigo_z[  
processErrorCode(responseCode); H2gj=krK  
return -2; //-2 represent access is error {aKqXL[UP  
} F#|O@.tDG  
`XTh1Z\  
Upl6:xYrG  
String sHeader; |rRO@18dA  
fr6^nDY  
_Yb _D/  
for(int i=1;;i++) j '%4{n  
{ iItcN;;7  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4\t1mocCSN  
//Utility.log(in.readLine()); W~T}@T:EN  
sHeader=httpConnection.getHeaderFieldKey(i); #PvB/3  
if(sHeader!=null) ! {,F~i9  
{ EC&@I+'8Q  
if(sHeader.equals("Content-Length")) co4h*?q  
{ n#Dv2 E=6  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y>."3*^  
break; :S@1  
} w^k;D,h  
} }]1BO  
else \h<BDk*  
break; 89}Y5#W  
} gE/Tj$  
} ',7??Q7j&v  
catch(IOException e){e.printStackTrace ();} ?VU(Pq*`  
catch(Exception e){e.printStackTrace ();} .k{ j]{k  
u#7+U\  
2g{)AtK$#  
Utility.log(nFileLength); vY|^/[x#B  
p4>$z& _  
#h!*dj"  
return nFileLength; 9ch#}/7B  
} Z[!d*O%R_  
 q}Z3?W  
T70QJ=,  
//保存下载信息(文件指针位置) FxG7Pk+=  
private void write_nPos() 6Z?j AXGSq  
{ @xsP5je]  
try{ |xr%6 [Ff  
output = new DataOutputStream(new FileOutputStream(tmpFile)); n@C~ev@%S  
output.writeInt(nStartPos.length); _;A $C(  
for(int i=0;i<nStartPos.length;i++) ~Aad9yyi  
{ Nb2Qp K  
// output.writeLong(nPos); 9&%fq)gS  
output.writeLong(fileSplitterFetch.nStartPos); 6!iJ;1PeE  
output.writeLong(fileSplitterFetch.nEndPos); /T^ JS  
} F,Xo|jjj  
output.close(); ek aFN\  
} cR-~)UyrO  
catch(IOException e){e.printStackTrace ();} Ax3W2s  
catch(Exception e){e.printStackTrace ();} pb60R|k  
} ( <t_Pru  
/e\{    
z!QDTIb  
//读取保存的下载信息(文件指针位置) t-u|U(n  
private void read_nPos() =bh*[ , -  
{ ~H)4)r^  
try{ "i.r@<)S  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nm$Dd~mxW1  
int nCount = input.readInt(); d &cU*  
nStartPos = new long[nCount]; SQsSa1  
nEndPos = new long[nCount]; SDG-~(Y  
for(int i=0;i<nStartPos.length;i++) x)rlyjFM  
{ ? Q@kg  
nStartPos = input.readLong(); PMsz`  
nEndPos = input.readLong(); XB hb`AG  
} q"KnLA(  
input.close(); T@wcHg  
} :Br5a34q  
catch(IOException e){e.printStackTrace ();} a^qNJ?R !  
catch(Exception e){e.printStackTrace ();} Y-piL8Xc  
} 6TWWl U^e  
5 v^yQ<70  
$!vxVs9n  
private void processErrorCode(int nErrorCode) I|oT0y &  
{ 31^cz*V  
System.err.println("Error Code : " + nErrorCode); <q)4la  
} Dq\ Jz~  
>>l`,+y  
%x; x_  
//停止文件下载 LL^q1)o  
public void siteStop() ?B@;QjhjiJ  
{ ;:S&F  
bStop = true; e/_C  
for(int i=0;i<nStartPos.length;i++) s6*ilq1  
fileSplitterFetch.splitterStop(); uaw~r2  
)'4P.>!!aQ  
Mpue   
} _R|Ify#J  
} yZ]:y-1  
//负责部分文件的抓取 9L0GLmLk1u  
**FileSplitterFetch.java vg Ipj3u  
*/ 4nfu6Dq  
package NetFox; g3n'aD@'x  
[$(%dV6O  
->z54 T  
import java.io.*; 8eIUsI.o  
import java.net.*; g]@ (E  
mM.*b@d-  
`cz2DR-"  
public class FileSplitterFetch extends Thread { &ad I (s~  
c'6g*%2k  
TQX)?^Ft  
String sURL; //File URL #v#<itfFH  
long nStartPos; //File Snippet Start Position GY3 Wj  
long nEndPos; //File Snippet End Position l:;PXy6)  
int nThreadID; //Thread's ID e<7.y#L  
boolean bDownOver = false; //Downing is over +[@z(N-h  
boolean bStop = false; //Stop identical TlL^7f}  
FileAccessI fileAccessI = null; //File Access interface c@[:V  
0<"k8 k@J  
J2q,7wI#  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :Eh\NOc_O  
{ |@?%Ct  
this.sURL = sURL; mOpTzg@  
this.nStartPos = nStart; r;9 r!$d  
this.nEndPos = nEnd; pA.J@,>`}  
nThreadID = id; wHZW `  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <H3ezv1M  
} uY_SU-v  
Xdi:1wW@p  
j.~!dh$mg  
public void run() i"zuil  
{ g 6]epp[8  
while(nStartPos < nEndPos && !bStop) ZN"j%E{d  
{ rrg96WD  
:.(;<b<\  
CO-_ea U(  
try{ )}Q(Tl\$  
URL url = new URL(sURL); J{[n?/A{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WPZ?*Sx  
httpConnection.setRequestProperty("User-Agent","NetFox"); i| \6JpNA:  
String sProperty = "bytes="+nStartPos+"-"; jA".r'D%  
httpConnection.setRequestProperty("RANGE",sProperty); YDC mI@  
Utility.log(sProperty); 4?N8R$  
r|4t aV&  
PFUO8>!pA\  
InputStream input = httpConnection.getInputStream(); ,F&g5'  
//logResponseHead(httpConnection); >+. ( r]  
+% /s*EC'w  
fQrhsuCrC  
byte[] b = new byte[1024]; y(R? ,wa=]  
int nRead; Li*eGlId  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OY[e.N t&  
{ aA7=q=  
nStartPos += fileAccessI.write(b,0,nRead); |AZg*T3:W  
//if(nThreadID == 1) Vcd.mE(t%  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B?VhIP e  
} p=/m  
Kn+S,1r  
H>r!i 4l  
Utility.log("Thread " + nThreadID + " is over!"); zy*/T>{#  
bDownOver = true; "#mBcQ;QLV  
//nPos = fileAccessI.write (b,0,nRead); cj11S>D  
} ?UM*Xah  
catch(Exception e){e.printStackTrace ();} 4Llo`K4  
} VDTcR  
} c8Z wr]DF  
UH7jP#W%=  
oyo(1 >  
//打印回应的头信息 -i-?.:  
public void logResponseHead(HttpURLConnection con) 8p[)MiC5W^  
{ RK w$-7O  
for(int i=1;;i++) boG_f@dv(  
{ P2 Vg4   
String header=con.getHeaderFieldKey(i); G[jW<'f  
if(header!=null) Z"unF9`"1  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;c$J=h]  
Utility.log(header+" : "+con.getHeaderField(header)); $XoQ]}"O  
else k4 F"'N   
break; .F+@B\A<  
} FLEo*9u>b  
} @JdZ5Q  
NHlk|Y#6b  
a&vY!vx 3  
public void splitterStop() S*yjee<@  
{ +^;JS3p@\  
bStop = true; n_'{^6*O  
} (5\N B0  
(h:Rh  
3G kv4,w<  
} #:SNHM^><  
\l~*PG2  
*2jK#9"MP  
/* B7imV@<  
**FileAccess.java @IXsy  
*//文件访问(定位,写) {T].]7Z  
package NetFox; O$cHZs$  
import java.io.*; <tioJG{OT  
r7qh>JrO  
D_Bb?o5  
public class FileAccessI implements Serializable{ T1H"\+  
G}p\8Q}'  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zl`h~}I  
RandomAccessFile oSavedFile; 9?k_y ZV  
long nPos; 8U_{|]M  
Dl}$pN  
mx=BD'  
public FileAccessI() throws IOException c/ uNM  
{ A~mum+[5  
this("",0); A@Dw<.&_I  
} TiH) 5  
k!{p7*0  
A= w9V  
public FileAccessI(String sName,long nPos) throws IOException x,'!eCKN  
{ r hfb ftw  
oSavedFile = new RandomAccessFile(sName,"rw"); vY_-Ranj#.  
this.nPos = nPos; (P`3 @H  
oSavedFile.seek(nPos); +$Rt+S BD  
} \nP>:5E1  
0P]E6hWgg  
iJ~Vl"|m  
public synchronized int write(byte[] b,int nStart,int nLen) Ox@P6|m  
{ *2GEnAZb7n  
int n = -1; ^urDoB:  
try{ .(WQYOMl0  
oSavedFile.write(b,nStart,nLen); v~Y^r2  
n = nLen; :GJ &_YHf  
} !3ctB3eJ  
catch(IOException e) ki)#d' }  
{ M4W5f#C5Ee  
e.printStackTrace (); LupkrxV  
} wT{nu[=GH*  
9WR6!.y#f  
<Z/x,-^*<  
return n; +U3m#Y)k  
} {.?/)  
Ct%x&m:  
cSm%s  
} jt.3P  
%?Ev|:i`@  
j.@\3'  
/* $ O5UyKI  
**SiteInfoBean.java X<*U.=r)  
*/ }3L@J8:D"  
package NetFox; NW&b&o  
k{Aj^O3gD  
C;vtY[}<  
public class SiteInfoBean { c=`wg$2:5  
z'EajBB\f  
}O4^Cc6  
private String sSiteURL; //Site's URL w4d--[Q  
private String sFilePath; //Saved File's Path s]JF0584  
private String sFileName; //Saved File's Name =%BZ9,l  
private int nSplitter; //Count of Splited Downloading File @$+ecaVW  
.uk>QM s1  
go<W( ,O  
public SiteInfoBean() ]]wA[c~G  
{//nSplitter的缺省值为5 : 7`[$<~E  
//default value of nSplitter is 5 Zc`BiLzrIG  
this("","","",5); >L 0_dvr  
} ]V#M%0:Q82  
v3jg~"!  
;IokThI  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iS<I0\D  
{ y7i*s^ys{  
sSiteURL= sURL; L# 2+z@g  
sFilePath = sPath; HZf/CE9T  
sFileName = sName; G JqJlgHe  
this.nSplitter = nSpiltter; `u&Zrdr,  
KSN Pkd6  
9*1,!%]  
} Ch3jxgQY  
7 !JQB  
#Q`dku%V:  
public String getSSiteURL() &E=>Hj(dTG  
{ b8LLr;oQw  
return sSiteURL; vsl]92xI  
} ]@Uq=?%  
{ >)#HD  
X'qU*Eo  
public void setSSiteURL(String value) ?pB>0b~3-  
{ d*%`!G  
sSiteURL = value; csW43&  
} ]n~ilS.rkl  
< RH UH)I  
T r1?620  
public String getSFilePath() DuHu\>f<S  
{  q;][5  
return sFilePath; ry`z(f  
} /Id%_,}Kb  
?}U(3  
gh8F 2V;<  
public void setSFilePath(String value) 6U R2IxbE  
{ 2 Cv4=S  
sFilePath = value; n' q4  
} ap+JQ@b  
.Lsavpo  
xY^ %&n  
public String getSFileName() e(GP^oK  
{ UZJCvfi  
return sFileName; 'DL`Ee\  
} [Q/TlOt5  
li}1S  
P;ci9vk  
public void setSFileName(String value) IV\'e}  
{ [nrYpb4  
sFileName = value; =06gj)8  
} ZOeQ+j)|I  
<YhB8W9 P  
$',K7%y  
public int getNSplitter() iiS-9>]/  
{ ,>0*@2  
return nSplitter; /7|V+6jV  
} DkvF5c&  
3@M|m<_R$  
\%f q  
public void setNSplitter(int nCount) XH}\15X  
{ x:7b/ j-  
nSplitter = nCount; &h^9}>rVjV  
} 1+jAz`nA:T  
} 34%RZG_o'  
l0PZ`m+;j  
4,CXJ2  
/* S~;4*7+?:  
**Utility.java > dI LF  
*/ DVB{2~7 4  
package NetFox; _/6!yyl  
--%N8L;e  
{MCi<7j<?  
public class Utility { X\@C.H2ttY  
V C24sU  
1DE<rKI  
public Utility() 2[ RoxKm  
{ tG9BfGF  
aTqd@},?  
*n 6s.$p)%  
} t>urc  
M^r1S  
//线程睡眠 [z`31F  
public static void sleep(int nSecond) j3{I /m  
{ G~2jUyv  
try{ }L+L"l&  
Thread.sleep(nSecond); %|g>%D3Z?  
} X(]WVCu  
catch(Exception e) A: 5x|  
{ (e!0]Io@  
e.printStackTrace (); njScz"L~  
} ^;Y|3)vvB  
} % NA9{<I  
E:JJ3X|  
//日志 VY;{/.Sa  
public static void log(String sMsg) )vjh~ybZ  
{ 6:Ch^c+IZ  
System.err.println(sMsg); x(etb<!jd  
} wQP^WzNE  
V5sg#|&  
s%C)t6`9  
public static void log(int sMsg) CFzNwgv]z  
{ \r /ya<5  
System.err.println(sMsg); m?pstuUK(  
} 5][Ztx  
} \`oT#|0  
xO^:_8=&:  
Vr6@> @SC  
/* I/d&G#:~  
**TestMethod.java v, n$^R  
*/ ,&j hlZ i  
package NetFox; *)ardZV${  
gVq;m>\|F  
:3XA!o&.T3  
public class TestMethod { YQ+tDZY8`  
K/tRe/t }  
(qqOjz   
public TestMethod() F~%]6^$w  
{ ///xx/weblogic60b2_win.exe 4 Y ;Nm1 @  
try{ & -{DfNKc  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i5Zk_-\#H  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :=/85\P0SU  
SiteFileFetch fileFetch = new SiteFileFetch(bean); %+8F'&X  
fileFetch.start(); Q<h-FW8z  
} TD'L'm|2  
catch(Exception e){e.printStackTrace ();} 0vEoGgY0*:  
0Fk5kGD,&K  
8TGOx%}i  
} Av xfI"sp  
`tHvD=`m.  
^* J2'X38I  
public static void main(String[] args) fBRo_CU8!  
{ XWA:J^  
new TestMethod(); M)eO6oX|  
} }`W){]{k O  
} 19O,a#{KHf  
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