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http断点续传简单实现(java)

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/* %SGO"*_  
**SiteFileFetch.java kPH^X}O$  
*/ v8Zg og)V  
package NetFox; bJm0  
import java.io.*; ~ ""MeaM8[  
import java.net.*; 3kCbD=yF  
Y14R"*t~  
{1aAm+  
public class SiteFileFetch extends Thread { `tG_O  
s vb4uvY  
<6C9R>  
SiteInfoBean siteInfoBean = null; //文件信息Bean j>xVy]v=|  
long[] nStartPos; //开始位置 N o(f0g.  
long[] nEndPos; //结束位置 2.D!4+&  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 #sU~fq  
long nFileLength; //文件长度 _oTT3[7P  
boolean bFirst = true; //是否第一次取文件 prN(V1O  
boolean bStop = false; //停止标志 U.U.\   
File tmpFile; //文件下载的临时信息 EcoUpiL%2  
DataOutputStream output; //输出到文件的输出流 ^P/D8cXa4  
?(q*U!=  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) rx>Tc#g  
public SiteFileFetch(SiteInfoBean bean) throws IOException 4i/q^;`  
{ 0>=)  
siteInfoBean = bean; J&:W4\ m  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); $ bNe0  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); zm+4Rl(  
if(tmpFile.exists ()) ]B3FTqR{i  
{ vvAk<[  
bFirst = false; x{>Y$t]  
read_nPos(); iBQBHF   
} &&1Y"dFs  
else $|(|Qzi%  
{ df6&Nu;4L  
nStartPos = new long[bean.getNSplitter()]; xzl4v=7  
nEndPos = new long[bean.getNSplitter()]; Cz r4 -#2  
} MLBg_<  
kA%OF*%|6  
&ORv bnd6  
>J3ja>Gw/  
} =9 M|o0aY  
BhW]Oq&  
|Xm4(FN\  
public void run() I"sobZ`  
{ W}k?gg=  
//获得文件长度 ,{?bM  
//分割文件 ]ZGvRA&  
//实例FileSplitterFetch ckN(`W,xp  
//启动FileSplitterFetch线程 $&=;9="  
//等待子线程返回 {]\uR-a(o  
try{ N~5WA3xd  
if(bFirst) HwW[M[qA  
{ s.;KVy,=Bu  
nFileLength = getFileSize(); G^rh*cb K  
if(nFileLength == -1) qH%L"J  
{ /;nO<X:XV  
System.err.println("File Length is not known!"); N~}v:rK>g  
} m0\"C-Bk  
else if(nFileLength == -2) n5k^v $'  
{ aC yb-P  
System.err.println("File is not access!"); .;Utkf'I  
} Z#Zzi5<  
else 4zqE?$HM'  
{ )SL@ >Cij  
for(int i=0;i<nStartPos.length;i++) _RaVnMJKX4  
{ ]2\2/~l  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 39T&c85  
} 3TiXYH  
for(int i=0;i<nEndPos.length-1;i++) |<3Q+EB^  
{ K;y\[2;}e,  
nEndPos = nStartPos[i+1]; b6!Q!:GO&  
} J4Z<Yt/  
nEndPos[nEndPos.length-1] = nFileLength; k[ffs}  
} ?Y0$X>nm  
} x|v[Dxf]  
M,\|V3s  
)/WA)fWkT  
//启动子线程 Ec*--]j*c  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $qlqW y-s  
for(int i=0;i<nStartPos.length;i++) p=-B~:  
{ ?%dCU~ z  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bpF@}#fT  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ( #-=y~%  
nStartPos,nEndPos,i); /[|}rqX(  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <[3lV)~t  
fileSplitterFetch.start(); )1Ma~8Y%r  
} TFJ{fLG  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [Yx-l;78  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [2QY  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @8M'<tr<z  
nEndPos = " + nFileLength); |,a%z-l  
// fileSplitterFetch[nPos.length-1].start(); RRI>bh]  
`FYtiv?G  
yo?g"vbE  
//等待子线程结束 &Qtp"#{  
//int count = 0; f=_Bx2ub  
//是否结束while循环 b#Fk>j  
boolean breakWhile = false; dWW-tHv#  
PK-}Ldj  
)-Mn"1ia  
while(!bStop) G {pP}  
{ kol,Qs  
write_nPos(); |%:q hs,  
Utility.sleep(500); )~?S0]j}  
breakWhile = true; [al(>Wr9  
np`g cj#  
k5fH ;  
for(int i=0;i<nStartPos.length;i++) f0cYvL ]  
{ }P&1s,S8J#  
if(!fileSplitterFetch.bDownOver) oz\{9Lwc  
{ ,<;l"v(  
breakWhile = false; M5T=Fj86  
break; :\1rQT  
} Lem\UD$D`  
} (:&&;]sI  
if(breakWhile) X|-v0 f  
break; |i} +t  
 \]f5  
q#Yg0w~  
//count++; >%n8W>^^4  
//if(count>4) 33{;[/4  
// siteStop(); HC9vc,Fp  
} M]6w^\4j9  
'FPcAW^8  
VeNNsg>&  
System.err.println("文件下载结束!"); fXF=F,!t  
} Xa{~a3Wy  
catch(Exception e){e.printStackTrace ();} fw1;i  
} v|4STR  
nxn[ ~~  
i_[ HcgT-  
//获得文件长度 Q8;x9o@p  
public long getFileSize() (1kn):  
{ 'uP'P#  
int nFileLength = -1; (opROsFh  
try{ AQnJxIL:  
URL url = new URL(siteInfoBean.getSSiteURL()); z&C{8aQ'  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {dy` %It  
httpConnection.setRequestProperty("User-Agent","NetFox"); a2c x  
Z%Tq1O  
a!c/5)v(  
int responseCode=httpConnection.getResponseCode(); d{iu+=NXz  
if(responseCode>=400) 7~!I2DV_  
{ ==-7F3QP  
processErrorCode(responseCode); l#2r.q^$|  
return -2; //-2 represent access is error #[k~RYS3  
} eHVdZ'%x  
r!=]Q}`F  
3i]"#wK  
String sHeader; dl*_ m3T  
U,%s;  
Q-! i$#-  
for(int i=1;;i++) RlI W&y  
{ S4l)TtY  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dJdD"xj  
//Utility.log(in.readLine()); G zJ9N`  
sHeader=httpConnection.getHeaderFieldKey(i); {+@ms$z  
if(sHeader!=null) q5:0&:m$4$  
{ wo7N7R5  
if(sHeader.equals("Content-Length")) AI^AK0.L  
{ 6pM"h5hA  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W\I$`gyC/  
break; Z #.GI  
} i#L6UKe:Q  
} 1?D8|<  
else " jl1.Ah  
break; {&\J)oZ  
} X;s 3y{ku  
} t/v@vJ`vSH  
catch(IOException e){e.printStackTrace ();} ~=`f]IL  
catch(Exception e){e.printStackTrace ();} =,&u_>Dp  
FSW3'  
DHh+%|e  
Utility.log(nFileLength); ppwd-^f3j  
w$DG=!  
]yyU)V0Iu  
return nFileLength; rtB|N-  
} +l2e[P+qA  
hr J$%U  
+L`V[;  
//保存下载信息(文件指针位置) B8bvp:Ho|  
private void write_nPos() HO 266M  
{ 89*S? C1  
try{ bh=\  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Tjd&^m  
output.writeInt(nStartPos.length); [=XZza.z  
for(int i=0;i<nStartPos.length;i++) T5 K-gz7A  
{ K%Usjezv&  
// output.writeLong(nPos); )HJK '@  
output.writeLong(fileSplitterFetch.nStartPos); + 6x"trC  
output.writeLong(fileSplitterFetch.nEndPos); GAg.p?Sq  
} > [Xm|A#  
output.close(); 2. StG(Y!  
} WafdE  
catch(IOException e){e.printStackTrace ();} H "Q(2I  
catch(Exception e){e.printStackTrace ();} 3mpP| b"  
} jG+T.  
R19'| TJ  
<h'8w  
//读取保存的下载信息(文件指针位置) #Y;.>mF  
private void read_nPos() %3]3r*e&5  
{ 21.YO]Et  
try{ !&@2  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile));  K&j' c  
int nCount = input.readInt(); z `\# $  
nStartPos = new long[nCount]; bcq@N  
nEndPos = new long[nCount]; f?2zLE>u  
for(int i=0;i<nStartPos.length;i++) mcvDxjk,h  
{ X tJswxw`K  
nStartPos = input.readLong(); ^OHZ767v  
nEndPos = input.readLong(); 'jh2**i 34  
} dj?G.-  
input.close(); V8-4>H}Cb/  
} Wl,%&H2S<  
catch(IOException e){e.printStackTrace ();} I 'x$,s  
catch(Exception e){e.printStackTrace ();} Q<z)q<e  
} * zd.  
,)Yao;Cvd  
5?^]1P_  
private void processErrorCode(int nErrorCode) MNkKy(Za  
{ ' " Bex`  
System.err.println("Error Code : " + nErrorCode); $`^H:Djr  
} DY$yiOH9  
PqTYAN&F  
'g. :MQ8  
//停止文件下载 '*8  
public void siteStop() {;U}:Dx  
{ w+Ad$4Pf"  
bStop = true; -s{R/6 :  
for(int i=0;i<nStartPos.length;i++) [Dnusp7e  
fileSplitterFetch.splitterStop(); (&q@~ dJ  
aLV~|$: 2  
%rFP#L  
} }%_qx|(P|t  
} .8-PB*vb  
//负责部分文件的抓取 )8:n}w  
**FileSplitterFetch.java #]"/{Z  
*/ 1Pu ,:Jt  
package NetFox; Q?W r7  
,Yo: &>As  
{PL,VY)Z  
import java.io.*; BeAk 21xb  
import java.net.*; 7^HpVcSM  
r Z pbu>S  
C=8H)Ef,l  
public class FileSplitterFetch extends Thread { 8a7YHUL<3i  
QT_Srw@  
L+_8QK<  
String sURL; //File URL wbBE@RU>!  
long nStartPos; //File Snippet Start Position C2NzP& FD  
long nEndPos; //File Snippet End Position {>S4 #^@}  
int nThreadID; //Thread's ID SzRL}}I  
boolean bDownOver = false; //Downing is over 2%bhW,?I  
boolean bStop = false; //Stop identical S<*';{5~  
FileAccessI fileAccessI = null; //File Access interface '=$TyiU  
MdLj,1_T  
~Hs=z$  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cnbo +U  
{ 9_eS`,'  
this.sURL = sURL; e!6eZ)l  
this.nStartPos = nStart; *`%4loW  
this.nEndPos = nEnd; ~M*7N@D  
nThreadID = id; sb'lZFSP~s  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sbzeY 1  
} 9-B@GFB;8  
D^N[=q99&e  
 X@cSP7b  
public void run() ?b5H 2 W  
{ eVTO#R*'|  
while(nStartPos < nEndPos && !bStop) }&mj.hGv  
{ {798=pC<.  
AYt*'Zeg!s  
]Uu aN8  
try{ b"^\)|*4;  
URL url = new URL(sURL); r9<V%PH v  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fa"\=V2S  
httpConnection.setRequestProperty("User-Agent","NetFox"); ZH% we  
String sProperty = "bytes="+nStartPos+"-"; Ohc^d"[7  
httpConnection.setRequestProperty("RANGE",sProperty); hRk,vB ]  
Utility.log(sProperty); _<XgC\4O|  
0Qt~K#mr/  
:|=- (z  
InputStream input = httpConnection.getInputStream(); h5 j<u  
//logResponseHead(httpConnection); TWtC-wI;  
3=IG#6)~C  
$%B5$+  
byte[] b = new byte[1024]; _n7%df  
int nRead; h:_NA  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~bWhth2*  
{ JXL'\De ;  
nStartPos += fileAccessI.write(b,0,nRead); m!;G/s*  
//if(nThreadID == 1) ;>5,  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,|A{!j`  
}  $<:'!#%  
vpi l$Uq  
& wOE\TCL  
Utility.log("Thread " + nThreadID + " is over!"); 8'+7i8e  
bDownOver = true; Xt\Dy   
//nPos = fileAccessI.write (b,0,nRead); QOd!]*W`?m  
} 'g2vX&=$A  
catch(Exception e){e.printStackTrace ();} s_TD4~ $  
} Y^yG/F  
} FQ1arUOFW,  
ghX:"vV{n  
$:(z}sYQ7  
//打印回应的头信息 0Lx3]"v  
public void logResponseHead(HttpURLConnection con) ?H<~ac2e  
{ \d:h$  
for(int i=1;;i++) PFm\[2  
{ )}q uw"H  
String header=con.getHeaderFieldKey(i); g(nK$,c  
if(header!=null) 0juDuE?  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w?*j dwh,'  
Utility.log(header+" : "+con.getHeaderField(header)); ^zHRSO  
else CGkI\E  
break; 'P,,<nkr|  
} ?/)lnj)e{  
} u|T%Xy=LU  
Fk aXA.JE  
v:?o3 S  
public void splitterStop() 9Eu #lV  
{ sLZ>v  
bStop = true; 8sH50jeP  
} BO]=vH  
v"/TmiZ  
ZOC#i i`:  
} F'rt>YvF  
T30Zk*V  
",T` \8&@e  
/* h^Qh9G0dn  
**FileAccess.java ETe-  
*//文件访问(定位,写) lAz2%s{6  
package NetFox; P sp^@  
import java.io.*; .N!{ U  
6W$rY] h!  
QE3ryD  
public class FileAccessI implements Serializable{ BD4`eiu"  
#%4=)M>^  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Hk~k@Wft  
RandomAccessFile oSavedFile; aTG[=)x L  
long nPos; VcrVaBw  
?|lIXz  
6Etss!_  
public FileAccessI() throws IOException qrpb[)Ll  
{ f0u56I9  
this("",0); 4 A5t*e  
} Oi6Eo~\f  
5tMh/]IeS  
$HxS:3D%D  
public FileAccessI(String sName,long nPos) throws IOException l 1|~  
{ KXq_K:r?  
oSavedFile = new RandomAccessFile(sName,"rw"); 3T?f5+@I  
this.nPos = nPos; 'u1=XX h  
oSavedFile.seek(nPos); +v!v[qn  
} Hsgy'X%om  
TOrMXcn!/  
0d";Hh:  
public synchronized int write(byte[] b,int nStart,int nLen) e62y  
{ _; 7fraqX  
int n = -1; +2Z#M  
try{ YNk|+A.<d  
oSavedFile.write(b,nStart,nLen); Ch7Egz l7?  
n = nLen; i%MA"I\9  
} `zY!`G  
catch(IOException e) DRp&IP<  
{ nc&Jmo7  
e.printStackTrace (); HA1]M`&  
} O) 1E$#~  
S+iP^*L,c  
$o"g73`3  
return n; VXwPdMy*L  
} ogJ<e_ m  
nP OO3!<{  
3}j1RYtz  
} Za0gs @$  
St2Q7K5s{  
0E1=W 6UZ  
/* ~{P:sjsU  
**SiteInfoBean.java rd" &QB{  
*/ @701S(0 '7  
package NetFox; ^SAq^3^P!  
@/ k x er  
ULIFSd Y  
public class SiteInfoBean { gB >pd?d  
H]]c9`ayt  
~z`/9 ;  
private String sSiteURL; //Site's URL eC;!YG Z  
private String sFilePath; //Saved File's Path J.W Ho c  
private String sFileName; //Saved File's Name T/NjNEd#  
private int nSplitter; //Count of Splited Downloading File LXNQb6!  
}PZ=`w*O  
4'm q_o#4W  
public SiteInfoBean() vd(dNu&,<  
{//nSplitter的缺省值为5 xW\,KSK  
//default value of nSplitter is 5 vK:QX$b  
this("","","",5); T .hb#oO  
} 7*;^UqGjz  
C\A49q  
,T{oy:rB  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ??(Kwtx{  
{ qv uxhzF  
sSiteURL= sURL; '?8Tx&}U8  
sFilePath = sPath; # 66e@  
sFileName = sName; >XnO&hW  
this.nSplitter = nSpiltter; Um\0i;7 ~4  
8YKQIt K  
~#Aa Ldq  
} r )8z#W>s  
"xn|zB  
LABNj{=D!  
public String getSSiteURL() :Y^I]`lR"  
{ ]u0Jd#@  
return sSiteURL; a_{6Qdl  
} 1eD.:_t4  
:<%vE!$  
@)b^^Fp  
public void setSSiteURL(String value) .8(%4ejJ(  
{ ;UpJ=?W  
sSiteURL = value; :Eo8v$W\RB  
} />F.Nsujy  
Hk9U&j$  
T>F9Hs  W  
public String getSFilePath() /AR]dcL@76  
{  D%gGRA  
return sFilePath; az2X ch]  
} 0m&3?"5u  
,E9d\+j  
anC+r(jjg9  
public void setSFilePath(String value) eO[c lB  
{ |!}wF}iLc)  
sFilePath = value; pX_b6%yX(  
} F~R7~ZE  
7kd|K b(  
OD|1c6+X  
public String getSFileName() ,ux+Qz5(  
{ ]7vf#1i<  
return sFileName; 7=3O^=Q ^Q  
} hy!6g n  
n|C|&  
agT7=hX].  
public void setSFileName(String value) Q7(eq0na  
{ CjKRP;5  
sFileName = value; ?bI?GvSh  
} J3IRP/*z  
!Rqx2Q  
gQ+9xTd  
public int getNSplitter() ]nc2/S%  
{ ._,trb>o  
return nSplitter; 61|B]ei/  
} mf2Mx=oy  
p:tN642  
km4g}~N</  
public void setNSplitter(int nCount) 9I kUZW  
{ jCQho-1QN  
nSplitter = nCount; K(3&27sGN  
} P^zy;Qs7  
} A{(T'/~"  
41}/w3Z4  
DxfMqH[vs  
/* ls @5^g  
**Utility.java Ay%:@j(E  
*/ wv^b_DR  
package NetFox; (OqHfv  
4swKjN &  
1Is%]6  
public class Utility { GA@ Ue9  
c/'M#h)"  
wko2M[  
public Utility() [%~^kq=|  
{ [gZDQcU  
k%Eh{dA  
i| 4_ m  
} xYwkFB$$*  
`xIh\q  
//线程睡眠 tW(+xu36  
public static void sleep(int nSecond) )eq}MaW+j  
{ H&K3"Ulw  
try{ 85hQk+Bu4  
Thread.sleep(nSecond); 0x71%=4H^x  
} y ||@?Y  
catch(Exception e) " 5|\X<f  
{ >?V<$>12  
e.printStackTrace (); )&z4_l8`=  
} Pi){h~B>  
} <jFSj=cIL  
k* Pz&8|  
//日志 @h(!<Ux_  
public static void log(String sMsg) c'rd$  
{ [Xh\m DU.  
System.err.println(sMsg); pYh!]0n  
} $T/#1w P  
= t-fYV  
PCZ]R  
public static void log(int sMsg) +6376$dC  
{ @/(@/*+"  
System.err.println(sMsg); LzE/g)>  
} $iHoOYx]<  
} ZqP7@fO_%  
#TATqzA  
+c r  
/* &57U? oY  
**TestMethod.java !qw4mN  
*/ ,R}Z=w#  
package NetFox; $}4K`Iu  
2&x7W*  
oZ-FF'  
public class TestMethod { GA ik;R  
8f-:d]  
;dOs0/UM&  
public TestMethod() Mciq-c)  
{ ///xx/weblogic60b2_win.exe PI63RH8e  
try{  0Ve%.k  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )-q\aX$])  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uS-3\$  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6F-JK1i  
fileFetch.start(); J[r^T&o  
} <A{y($  
catch(Exception e){e.printStackTrace ();} OAVQ`ek  
E*^ 9|Y[  
SUc6/'Rdr  
} `Hd9\;NJ  
]ViOr8u  
iD`k"\>9  
public static void main(String[] args) HL8(lPgS  
{ 5H*>  
new TestMethod(); h ~fWE  
} r w\D>} \  
} gY%&IHQ'  
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