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http断点续传简单实现(java)

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/* b2=0}~LK  
**SiteFileFetch.java XNb ZNaAd  
*/ "0k8IVwp  
package NetFox; P#/HTu5q7  
import java.io.*; h=_0+\%  
import java.net.*; v\"S Gc  
?9=9C"&s  
Css l{B  
public class SiteFileFetch extends Thread { ;h" P{fF   
z.VyRBi0  
>ap1"n9k  
SiteInfoBean siteInfoBean = null; //文件信息Bean J@ktyd(P  
long[] nStartPos; //开始位置 Ze3X$%kWi  
long[] nEndPos; //结束位置 ^3FE\V/=  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ;/*6U  
long nFileLength; //文件长度 -TOIc%  
boolean bFirst = true; //是否第一次取文件 [kgdv6E  
boolean bStop = false; //停止标志 (%:>T Q(  
File tmpFile; //文件下载的临时信息 JHJ~X v  
DataOutputStream output; //输出到文件的输出流 Q\,o :ZU_  
TbF4/T1b  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) |xvy')(b  
public SiteFileFetch(SiteInfoBean bean) throws IOException 0% #<c p  
{ <ExZ:ip  
siteInfoBean = bean; tpTAeQ*:d  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); I]y.8~xs  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); %9#gB  
if(tmpFile.exists ()) :BGA.  
{ D\YE^8/  
bFirst = false; !GQ\"Ufs>  
read_nPos(); vuFBET,  
} |s)?cpb  
else 2',w[I  
{ K[7EOXLy  
nStartPos = new long[bean.getNSplitter()]; e<#DdpX!H~  
nEndPos = new long[bean.getNSplitter()]; I;?X f  
} wB{;bB{  
/Y2/!mU</  
F[!ckes<bB  
3u\;j; Td!  
} iIGbHn,/  
d@3}U6,  
]}6w#)]"  
public void run() 08m;{+|vY  
{ s{4\xAS>  
//获得文件长度 :aIN9;  
//分割文件 %D`,k*X  
//实例FileSplitterFetch \rV B5|D?  
//启动FileSplitterFetch线程 D*Q.G8(  
//等待子线程返回 5I@w~z  
try{ 6k/U3&R  
if(bFirst) DK&h eVIoZ  
{ %&\jOq~  
nFileLength = getFileSize(); Lh-`OmO0>F  
if(nFileLength == -1) WmQ 01v  
{ (?b@b[D~4  
System.err.println("File Length is not known!"); A;u"<KG?  
} 5]1h8PW!Y  
else if(nFileLength == -2) pBC<u  
{ {A o,t+j  
System.err.println("File is not access!"); 9lo [&^<  
} 'snYu!`z  
else iY bX  
{ cubk]~VD  
for(int i=0;i<nStartPos.length;i++) n!E2_  
{ T=YzJyQC)  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); **[Z^$)u(  
} X{-9FDW  
for(int i=0;i<nEndPos.length-1;i++) 9Of FM9(:  
{ =[<m[.)i  
nEndPos = nStartPos[i+1]; g+C!kaC)  
} S? 0)1O  
nEndPos[nEndPos.length-1] = nFileLength; :b,^J&~/)1  
} N|2y"5  
} Y3ZK%OyPR  
J%]D%2vnk`  
^5t  
//启动子线程 Ut)r&?  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2_t=P|Uo  
for(int i=0;i<nStartPos.length;i++) 9(!]NNf!  
{ -6Mm#sX  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O8N[Jl  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O;]?gj 1@  
nStartPos,nEndPos,i); Sb:T*N0gS  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vG2b:[W  
fileSplitterFetch.start(); <39!G7ny  
} lKEa)KF[  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y#01o&f0n  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kDz>r#%  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wn11\j&  
nEndPos = " + nFileLength); [W,-1.$!dM  
// fileSplitterFetch[nPos.length-1].start(); n|4;Hn1V  
hD<f3_k  
XL}<1- }  
//等待子线程结束 L6i|:D32p  
//int count = 0; %E27.$E_  
//是否结束while循环 ~-F?Mc  
boolean breakWhile = false; 6b Z[Kt  
#rYENR[  
u; TvS |  
while(!bStop) WIh@y2&R  
{ p11G#.0  
write_nPos(); Jll-X\O`-  
Utility.sleep(500);  \`xkp[C  
breakWhile = true; ! ]Mc4!E  
Z]:BYX'  
u&TdWZe  
for(int i=0;i<nStartPos.length;i++) $X+u={]  
{ u:` y]  
if(!fileSplitterFetch.bDownOver) g3?U#7i  
{ ? 4)v`*  
breakWhile = false; r[Zq3  
break; q?~Rnv  
} ZcryAm:I  
} $~'Tf>e  
if(breakWhile) ?Cci:Lin  
break; O(OmGu4%  
n!N\zx8  
(3EUy"z-  
//count++; /b.oEGqZX  
//if(count>4) Y&'8VdW  
// siteStop(); 8 HoP( +?  
} qvLDfN  
C 7n Kk/r  
!g 0cC.'  
System.err.println("文件下载结束!"); XSB8z   
} ?(im+2  
catch(Exception e){e.printStackTrace ();} amB@N6*  
} \}inT_{g  
+|C[-W7Sw  
:J(sXKr[C  
//获得文件长度 @PcCiGZ  
public long getFileSize() nJVp.*S  
{ {(vOt'  
int nFileLength = -1; ,{j4  
try{ +*t|yKO>[  
URL url = new URL(siteInfoBean.getSSiteURL()); .T3=Eq&"W  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z%v6xP.  
httpConnection.setRequestProperty("User-Agent","NetFox"); jFj~]]j  
vg5NY =O  
B2hfD-h,>  
int responseCode=httpConnection.getResponseCode(); P&t;WPZ  
if(responseCode>=400) Dc FCKji  
{ i@$-0%,  
processErrorCode(responseCode); *e<_; Kr?  
return -2; //-2 represent access is error .u< U:*  
} LC'2q*:'  
( D}" &2  
|@`"F5@,  
String sHeader; *:arva5  
:z~!p~  
w4:<fnOM  
for(int i=1;;i++) \X@IkL$r  
{ XU#,Bu{  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /Antb6E  
//Utility.log(in.readLine()); .k]#XoE  
sHeader=httpConnection.getHeaderFieldKey(i); z/vDgH!s  
if(sHeader!=null) org*z!;.   
{ r69WD .  
if(sHeader.equals("Content-Length")) 9oq)X[  
{ 5V|tXsy:  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *j<@yG2\gP  
break; O: u%7V/  
} #,P(isEZ"  
} HIPL!ss]  
else  6`"ZsO  
break; `D)S-7BR  
} 5<r)+?!n  
} ? -{IsF^  
catch(IOException e){e.printStackTrace ();} .cw=*<zeg  
catch(Exception e){e.printStackTrace ();} eG^z*`**  
aL$j/SC  
/'+4vXc@  
Utility.log(nFileLength); Y~GUR&ww0n  
s=\7)n=,M  
nh|EZp]  
return nFileLength; *dVD  
} c'lIWuL)  
P6E1^$e  
htg'tA^CtS  
//保存下载信息(文件指针位置) ./)j5M  
private void write_nPos() a^*B5G1(&  
{ T]X{ @_  
try{ ZE ^u.>5  
output = new DataOutputStream(new FileOutputStream(tmpFile)); \#_@qHAG  
output.writeInt(nStartPos.length); Deog4Ol"/  
for(int i=0;i<nStartPos.length;i++) K*[0dza$  
{ rUvwpP"k  
// output.writeLong(nPos); ;y ,NC2Xj  
output.writeLong(fileSplitterFetch.nStartPos); FP@ A;/c  
output.writeLong(fileSplitterFetch.nEndPos); _3zU,qm+  
} Obg@YIwn  
output.close(); 4Q/r[x/&C  
} z,os MS  
catch(IOException e){e.printStackTrace ();} ev*c4^z:s  
catch(Exception e){e.printStackTrace ();} >T(M0Tkt  
} Cea"qNq=k  
4&H+hN{3  
mf#fA2[  
//读取保存的下载信息(文件指针位置) TR|;,A[%v#  
private void read_nPos() 3lyQn "  
{ |M]sk?"^  
try{ 6WCmp,*  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .!!79 6hS  
int nCount = input.readInt(); dzpj9[  
nStartPos = new long[nCount]; 0%#t[us Y  
nEndPos = new long[nCount]; h#vL5At  
for(int i=0;i<nStartPos.length;i++) Z<w,UvJa  
{ fdg[{T4:  
nStartPos = input.readLong(); , &-S?|  
nEndPos = input.readLong(); wYC9 ~ms-  
} 9Zs #Ky/  
input.close(); 5 1v r^  
} Cl%V^xTb  
catch(IOException e){e.printStackTrace ();} 1 VPg`+o  
catch(Exception e){e.printStackTrace ();} Y#GT*V  
} 6R0D3kW  
R>^5$[  
4+BrTGp  
private void processErrorCode(int nErrorCode) pq%t@j(X  
{ &8R-C[A  
System.err.println("Error Code : " + nErrorCode); ;:-}z.7Y  
} Oz_b3r  
<m-Ni  
wOD/Z8  
//停止文件下载 Ky =(urAd  
public void siteStop() s{b0#[  
{  /<(R  
bStop = true; TG""eC!E  
for(int i=0;i<nStartPos.length;i++) X`8Y[Vb3}  
fileSplitterFetch.splitterStop(); yz54:q?  
O e0KAn  
y}3 `~a  
} EU`' 8*4  
} c80"8r  
//负责部分文件的抓取 ,C5@ P+A  
**FileSplitterFetch.java g)2m$#T&s  
*/ .&aVx]  
package NetFox; e7)>U!9c9  
iPRJA{$b_  
4nX'a*'D~}  
import java.io.*; 3hp tP  
import java.net.*; o.v,n1Nm  
C.B8 J"T-  
> 2!^ dT^D  
public class FileSplitterFetch extends Thread { SLbavP#G  
+btP]?04  
T%z!+/=&^  
String sURL; //File URL gK]T}  
long nStartPos; //File Snippet Start Position [kU[}FT  
long nEndPos; //File Snippet End Position 5d!z<{`  
int nThreadID; //Thread's ID '6Rs0__  
boolean bDownOver = false; //Downing is over C5W-B8>  
boolean bStop = false; //Stop identical b*$o[wO9  
FileAccessI fileAccessI = null; //File Access interface F ~11 _  
RMs1{64:  
r;5 AY  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d@`-!"  
{ SO8|]Fk  
this.sURL = sURL; }&'yt97+  
this.nStartPos = nStart; k_.j%  
this.nEndPos = nEnd; wE.@0  
nThreadID = id; &El[  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '<U[;H9\  
} +eH=;8  
N-_| %C-.  
_3g %F  
public void run() C$EFh4  
{ j+ T\c2d  
while(nStartPos < nEndPos && !bStop) Q'V,?#  
{  I$sm5oL  
j4hUPL7  
!&:.Uh  
try{ ~(L<uFU V  
URL url = new URL(sURL); I n%yMH8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yW7S }I  
httpConnection.setRequestProperty("User-Agent","NetFox"); '$&(+>)z `  
String sProperty = "bytes="+nStartPos+"-"; 3  %{'Uh,  
httpConnection.setRequestProperty("RANGE",sProperty); (Su2 \x  
Utility.log(sProperty); 9\;/-0P  
"{1}  
Zm'::+ tl  
InputStream input = httpConnection.getInputStream(); MLDg).5  
//logResponseHead(httpConnection); &JzF   
=u1w\>(2Y  
5v03<m0`y  
byte[] b = new byte[1024]; B7^n30+L  
int nRead; Xf/<.5A  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;`Ch2b1+  
{ _-2n3py  
nStartPos += fileAccessI.write(b,0,nRead); V s t e$V  
//if(nThreadID == 1) 2nz'/G  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o\Vt $  
} rcb/X`l=  
T;e(Q,!H  
XzwQ,+IAr  
Utility.log("Thread " + nThreadID + " is over!"); $@!&ML  
bDownOver = true; (E]K)d  
//nPos = fileAccessI.write (b,0,nRead); YedipYG9;  
} ]m,p3  
catch(Exception e){e.printStackTrace ();} mI*>7?  
} [==Z1Q;=  
} !ZcA Ltq  
!ef)Ra-W  
2PW3 S{Dt  
//打印回应的头信息 ^mb*w)-p?  
public void logResponseHead(HttpURLConnection con) 5rSth.&  
{ 43]&SXprH  
for(int i=1;;i++) !a&F:Fbm  
{ dfd%A" I  
String header=con.getHeaderFieldKey(i); `SbX`a0p2  
if(header!=null) zL{@LHP  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q&\ksM  
Utility.log(header+" : "+con.getHeaderField(header)); "N"k8,LH  
else s'w 0pZqj  
break; r>eXw5Pr7  
} a{6|[a R  
} mTbPz Z4  
R-|]GqS}L  
P"VLGa  
public void splitterStop() AV`7> @  
{ _ !vbX mb  
bStop = true; T8oASg!  
} JFkjpBS  
aDEP_b;  
 'Z}$V*  
} HAdm,  
j> M%?Tw  
FkkB#Jk4  
/* 0`=?ig_  
**FileAccess.java $~\qoW<  
*//文件访问(定位,写) c9k,Dc  
package NetFox; B75SLK:h=  
import java.io.*; c9={~  
Q&;qFv5-l  
T!E LH!  
public class FileAccessI implements Serializable{ (9%%^s]uPT  
sP8B?Tn1W  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^9E(8DD  
RandomAccessFile oSavedFile; o%7yhCY  
long nPos; ?2Dz1#%D  
Kj5f:{Ur  
] lTfi0}g_  
public FileAccessI() throws IOException YiMecu  
{ \rO>F E  
this("",0); J'v|^`bE  
} 3E9j%sYk  
CAO{$<M5m  
;c}];ZU3G  
public FileAccessI(String sName,long nPos) throws IOException +r"$?bw '  
{ lvffQ_t  
oSavedFile = new RandomAccessFile(sName,"rw"); =Q/i< u  
this.nPos = nPos; exvsf|  
oSavedFile.seek(nPos); upKrr  
} #nz$RJsX  
3~'F^=T.Y  
85]UrwlA4  
public synchronized int write(byte[] b,int nStart,int nLen) vZsVxx99  
{ <Z[R08 k  
int n = -1; 4[wP$  
try{ #a:C=GV;4  
oSavedFile.write(b,nStart,nLen); N<%,3W_-_  
n = nLen; :Tl?yG F  
} N<WFe5  
catch(IOException e) L1BpY-=  
{ 'z:p8"h}  
e.printStackTrace (); b.+\qaR  
} egvWPht'_  
9IV WbJ  
?i"FdpW  
return n; gw^+[}U#  
} ~E~J*R Ze  
^DOcw@Z6HC  
FW,D\51pTP  
} sjGZ ,?%  
7\ lb+^$  
cCs:z   
/* WBIS  
**SiteInfoBean.java RCr:2 Iz  
*/ i :72FVo  
package NetFox; 8!fw Xm  
,5 ,4Qf7  
d8I/7 ;F X  
public class SiteInfoBean { }z #8vE;  
'cv/"26#  
bcG-js-  
private String sSiteURL; //Site's URL ai RNd~\  
private String sFilePath; //Saved File's Path ~r3g~MCHS  
private String sFileName; //Saved File's Name E%N]t} }[  
private int nSplitter; //Count of Splited Downloading File q)X&S*-<o~  
oxZ(qfjS  
WP9=@X Z  
public SiteInfoBean() :C5N(x  
{//nSplitter的缺省值为5 +Gko[<  
//default value of nSplitter is 5 4(]k=c1<  
this("","","",5); ikC;N5Sw  
} 8*X8U:.0o  
 T7`Jtqf  
c-F&4V  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >8so'7(  
{ YuZnuI@m9  
sSiteURL= sURL; @B6[RZR  
sFilePath = sPath; [sBD|P;M  
sFileName = sName; _=b[b]Ec$s  
this.nSplitter = nSpiltter; <G={V fr  
 ar yr  
ak zb<aT  
} eJ'ojc3  
jiat5  
d {4br  
public String getSSiteURL() dj#<,e\  
{ o <y7Ut  
return sSiteURL; .?qS8:yA  
} Jx]`!dP3  
U\N`[k.F  
bZ)Jgz  
public void setSSiteURL(String value) ;FU d.vg{  
{ n"JrjvS  
sSiteURL = value; WW.=>]7;  
} 2rk_ ssvs  
z3,z&Ra  
%PpB$  
public String getSFilePath() Yi:+,-Fso  
{ qXW 5_iX  
return sFilePath; P;GUGG*W  
} chy7hPxC;  
)u$A!+fo  
N.]8qzW  
public void setSFilePath(String value) =B\ ?(  
{ hn-S$3')`  
sFilePath = value; ]Q+Tm2{  
} <_5z^@N3$  
?AEpg.9R-  
)9$Xfq/  
public String getSFileName() ;]gph)2cd  
{ rv+"=g  
return sFileName; Z`D#L[z$  
} VH/_0  
I'";  
u}$?r\H'(  
public void setSFileName(String value) C..O_Zn{g  
{ yR&E6o.$z  
sFileName = value; "2)T=vHi#  
} \6o ~ i  
d%<Uh(+:  
W \"cp[b  
public int getNSplitter() B}vI<?c  
{ q8U]Hyp(`  
return nSplitter; \(Iy>L.  
} 3KGDS9I  
u+*CpKR}  
yuND0,e  
public void setNSplitter(int nCount) 3E#acnqn*  
{ (g 8K?Q  
nSplitter = nCount; ?/;<32cE,  
} &{$\]sv  
} {_ocW@@  
J4<- C\=4  
`Tab'7  
/* [p(Y|~  
**Utility.java ~ 60J  
*/ ]5^u^  
package NetFox; "ey~w=B$M  
DpA)Z ??  
1iUy*p65:  
public class Utility { BQm H9g|2  
T =:^k+  
E| No$QO)  
public Utility() I)6)~[:'  
{ %f@]-  
bygwoZ<E  
"UE'd Wz  
} UXd\Q''  
pJ{sBp_$  
//线程睡眠 _:{XL c  
public static void sleep(int nSecond) N-suBRnW  
{ q*2ljcb55  
try{ il*bsnwpZv  
Thread.sleep(nSecond); h4V.$e<T&  
} c| E  
catch(Exception e) k1X<jC]P  
{ rXA7<_Vg  
e.printStackTrace (); {1FY HM^  
} R!:1{1  
} k+&|*!j  
%hY+%^k.  
//日志 }lhJt|qc  
public static void log(String sMsg) /q8n_NR  
{ F$)Ki(m q  
System.err.println(sMsg); t.NG ]ejZ  
} J|s4c`=  
#bnFR  
/QTGZ b  
public static void log(int sMsg) ~dC^|  
{ $AoN,B>  
System.err.println(sMsg); =\tg$  
} % nJ'r?+h  
} _,5(HETE2  
p 3X>  
qV5ME #TJ  
/* ZYg="q0x&  
**TestMethod.java r3#H]c  
*/ VaH#~!  
package NetFox; Fe: 0nr9;  
=8[HC}s|$  
aVd{XVE  
public class TestMethod { ~W!sxM5(*  
LTrn$k3}  
O0wD"V^W  
public TestMethod() }nu hLt1  
{ ///xx/weblogic60b2_win.exe X|X6^}  
try{ o: TO[  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5);  y!!p:3  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Aj-}G^>#  
SiteFileFetch fileFetch = new SiteFileFetch(bean); W*gu*H^s~  
fileFetch.start(); je.mX/Lpj  
} JIDE]f  
catch(Exception e){e.printStackTrace ();} +.{_n(kU  
C%l~qf1n  
Rom|Bqo;  
} BB9Z?}  
Aqq%HgY:t  
\S3C"P%w  
public static void main(String[] args) IeE+h-3p  
{ eo"6 \3z  
new TestMethod(); l1a=r:WhH  
} v@[MX- ,8  
} Z{ &PKS  
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