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http断点续传简单实现(java)

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/* $(N+E,XB  
**SiteFileFetch.java 2E_d$nsJ  
*/ ~Blsj9a2  
package NetFox; 9`|~- b  
import java.io.*; o?((FW5.;  
import java.net.*; <:!;79T\  
OD yKS;   
t<H@c9{;*  
public class SiteFileFetch extends Thread { DEN (pA\  
^hyp}WN  
:#nv:~2]  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^#p+#_*V  
long[] nStartPos; //开始位置 K<~J*k<v  
long[] nEndPos; //结束位置 O]-s(8Oo3  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 x!;;;iS  
long nFileLength; //文件长度 %=<Kb\  
boolean bFirst = true; //是否第一次取文件 `#y?:s ]e  
boolean bStop = false; //停止标志 Ojs ^-R_  
File tmpFile; //文件下载的临时信息 >A*BRX"4C  
DataOutputStream output; //输出到文件的输出流 uK5 C-  
E0_S+`o2y  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) i564<1`x  
public SiteFileFetch(SiteInfoBean bean) throws IOException h:~ 8WV|  
{ Q/y"W,H#  
siteInfoBean = bean; ]v|n'D-?  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); V4tObZP3Ff  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); AB[#  
if(tmpFile.exists ()) ^7-l<R[T  
{ @*"H{xo.U  
bFirst = false; "Wn8}T*  
read_nPos(); V)#rP?Y  
} L3|~ i&k  
else #:M <<gk  
{ D?`|`Mu  
nStartPos = new long[bean.getNSplitter()]; !6pE0(V^+4  
nEndPos = new long[bean.getNSplitter()]; L`n Ma   
} bY!1t}ALh  
L)-1( e<x  
TV[@!E a  
H?$gHZPI  
} (GB*+@  
:7 OhplI  
DWmViuZmL  
public void run() "C'T>^qw*  
{ u3])_oj=  
//获得文件长度 ~=i<O&nai  
//分割文件 jPA^SxM  
//实例FileSplitterFetch U^ Ulj/%6  
//启动FileSplitterFetch线程 `2PvE4]%p  
//等待子线程返回 aZB$%#'vR  
try{ o@ W:PmKW  
if(bFirst) T.GB *  
{ AH'4k(-  
nFileLength = getFileSize(); fUa[3)I  
if(nFileLength == -1) 4elA<<  
{ Jx3fS2  
System.err.println("File Length is not known!"); ! w2BD^V-  
} MVXy)9q  
else if(nFileLength == -2) v|@1W Uc,g  
{ N5jJ,iz  
System.err.println("File is not access!"); /^Ng7Mi!  
} ![3l K  
else %mr6p}E|  
{ 84jA)  
for(int i=0;i<nStartPos.length;i++) .u\xA7X  
{ Q@5v> `  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); i2 7KuPjC  
} /@feY?glc  
for(int i=0;i<nEndPos.length-1;i++) &)GlLpaT  
{ P)rz%,VF+  
nEndPos = nStartPos[i+1]; _t.Ub:  
} M~LYq  
nEndPos[nEndPos.length-1] = nFileLength; (c|Ry[$|  
} =L9;8THY  
} Wj"GS!5  
wLOS , =  
' T%70)CM~  
//启动子线程 Ot([5/K  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $i;_yTht  
for(int i=0;i<nStartPos.length;i++) x A"V!8C  
{ )Oix$B!-  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <= Aqi91  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),  LAO2Py#  
nStartPos,nEndPos,i); GjeRp|_Qd<  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VK3e(7 b  
fileSplitterFetch.start(); 3U&r K)F  
} Bl*.N9*  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZP;WXB`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t^SND{[WcM  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gQ=l\/ H  
nEndPos = " + nFileLength); `~+[pY 1r  
// fileSplitterFetch[nPos.length-1].start(); ]5sU =\  
]o2 Z 14  
W $EAo+V  
//等待子线程结束 yR4++yk  
//int count = 0; _ a -At  
//是否结束while循环 6'6,ySo]  
boolean breakWhile = false; t# <(Q  
.qg 2zE$0  
?i5=sK\  
while(!bStop) D,&o=EU  
{ Zg/ ],/`  
write_nPos(); z%44@TP  
Utility.sleep(500); Dio9'&DtC  
breakWhile = true; X}G3>HcP  
,<O|Iis  
K~Z$NS^W&  
for(int i=0;i<nStartPos.length;i++) ;b;Bl:%?  
{ Zil<*(kv{  
if(!fileSplitterFetch.bDownOver) X-}]?OOs  
{ @D7/u88|  
breakWhile = false; :<i<\TH'  
break; }-2U,Xg[  
} [s&0O<Wv  
} Ah Rvyj  
if(breakWhile) >@?`n}r|  
break; B'!I{LC  
gib'f@i;  
\3 M%vJ  
//count++; /{ FSG!  
//if(count>4) 35Cm>X  
// siteStop(); Be~In~~  
} JHCXUT-r{  
dz=pL$C  
meArS*d  
System.err.println("文件下载结束!"); ;Wedj\Kkp  
} erdA ?  
catch(Exception e){e.printStackTrace ();} #v}pn2g%>  
} +5qY*$dn  
,B,:$G<  
vG#,J&aW  
//获得文件长度 v#b(0G  
public long getFileSize() JE ''Th}  
{ E4qQ  
int nFileLength = -1; b3l~wp6>  
try{ 8;5@5Au  
URL url = new URL(siteInfoBean.getSSiteURL()); 'A)9h7k}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LQXMGgp  
httpConnection.setRequestProperty("User-Agent","NetFox"); yL"UBe}v  
+!eh\.u|]  
;kR+jC(  
int responseCode=httpConnection.getResponseCode(); U_<k*o@:  
if(responseCode>=400) y?ypRCgO.u  
{ HA]5:ck  
processErrorCode(responseCode); T/iZ"\(~w  
return -2; //-2 represent access is error )kvrQ6  
} |ohCA&k%;  
v9XevLs  
=} flmUv~  
String sHeader; E?cf#;2h8m  
]3I@5}5%  
m)e~HP7M  
for(int i=1;;i++) rB}2F*eT  
{ ^C70b)68  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mae@L  
//Utility.log(in.readLine()); \.Z /  
sHeader=httpConnection.getHeaderFieldKey(i); n7(/ml+Q_  
if(sHeader!=null) ?#Y1E~N  
{ "mB /"  
if(sHeader.equals("Content-Length")) K-4o_:F  
{ J>Bc-%.Q  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *IIuGtS  
break; (Ky$(Ubb#6  
} .'zcD^  
} `[F[0fY-  
else *Z2#U ?_  
break; +XpQ9Cd  
} !MEA@^$#  
} cg_j.=M-  
catch(IOException e){e.printStackTrace ();} rHJtNN8$k  
catch(Exception e){e.printStackTrace ();} (Z?g^kjq)  
Dgm"1+  
(gjCm0#_%  
Utility.log(nFileLength); b0uWUI(=  
uy8mhB+]  
!m6=Us  
return nFileLength; s(cC ;  
} m*'87a9q0  
g4}K6)@  
)}i|)^J  
//保存下载信息(文件指针位置) Dn@Sjsj>  
private void write_nPos() _`+2e-  
{ A75z/O{  
try{ a}V<CBi  
output = new DataOutputStream(new FileOutputStream(tmpFile)); x/uC)xm  
output.writeInt(nStartPos.length); OpLUmn  
for(int i=0;i<nStartPos.length;i++) ,nSapmg  
{ yt#~n _  
// output.writeLong(nPos); /PZxF  
output.writeLong(fileSplitterFetch.nStartPos); Y;#H0v>E  
output.writeLong(fileSplitterFetch.nEndPos); BoP,MpF  
} I\P w`  
output.close(); r Fhi:uRV  
} Cp^`-=r+  
catch(IOException e){e.printStackTrace ();} #r'S@:[  
catch(Exception e){e.printStackTrace ();} 2k+u_tj>  
} j W/*-:  
A@)ou0[n@  
];*? `}#  
//读取保存的下载信息(文件指针位置) W4$F\y  
private void read_nPos() A9o"L.o)  
{ ub]"b[j\1  
try{ 5v"Sv  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2 sK\.yS  
int nCount = input.readInt(); <8BNqbX  
nStartPos = new long[nCount]; %:yVjb,Yf  
nEndPos = new long[nCount]; CtE <9?  
for(int i=0;i<nStartPos.length;i++)  J7p?9  
{ Vw+RRi(  
nStartPos = input.readLong(); X][=(l!;w7  
nEndPos = input.readLong(); fF.sT7Az+  
} !NTt' 4/F{  
input.close(); PE<(eIr  
} RSBk^  
catch(IOException e){e.printStackTrace ();} zszx~LSvIT  
catch(Exception e){e.printStackTrace ();} h~s h!W8  
}  S)x5.vo^  
7.bPPr&  
[WO>}rGw4  
private void processErrorCode(int nErrorCode) ')>D*e  
{ V=)' CCi{  
System.err.println("Error Code : " + nErrorCode); /A93mY[  
} &VTO9d  
Ue(\-b\)  
#Q$+AdY|  
//停止文件下载 rT';7>{g  
public void siteStop() {ZKXT8'  
{ 8K2=WYN  
bStop = true; Le*gdoW.  
for(int i=0;i<nStartPos.length;i++) &;[e  
fileSplitterFetch.splitterStop(); PGhYkj2  
"=!sZO?3  
b=XHE1^rM  
} q z8Jvgu?  
} W~Q;R:y  
//负责部分文件的抓取 fr<V])  
**FileSplitterFetch.java RL b o  
*/ ^1;Eq>u  
package NetFox; A$-\Er+f  
e`zCz`R  
,D2nUk  
import java.io.*; U U@  
import java.net.*; b)7v-1N  
Un Ocw  
K[l5=)G0L  
public class FileSplitterFetch extends Thread { 3M5wF6nY[[  
 I}u&iV`  
Y'76!Y  
String sURL; //File URL `_!R;f  
long nStartPos; //File Snippet Start Position oW3|b2D  
long nEndPos; //File Snippet End Position m-lTXA(  
int nThreadID; //Thread's ID DVjwY_nG7  
boolean bDownOver = false; //Downing is over 1@xdzKua1  
boolean bStop = false; //Stop identical zo:NE0 0  
FileAccessI fileAccessI = null; //File Access interface k1~? }+<e  
="de+S8W  
F[*/D/y(  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S#nW )=   
{ B!((N{4H+  
this.sURL = sURL; 6rMNp"!  
this.nStartPos = nStart; o8fY!C)  
this.nEndPos = nEnd; - *v)sP"@  
nThreadID = id; q,>4#J[2;s  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9*2^2GR^;  
} @k)[p+)E  
@@H?w7y?&  
,&G !9}EC  
public void run() ]|_+lik#  
{ 96i #  
while(nStartPos < nEndPos && !bStop) dz1kQzOU*  
{ ))4RgS$  
 1t }  
5IfC8drAs  
try{ z oZ10?ojC  
URL url = new URL(sURL); UdcrX`^.  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gl 27&'?E*  
httpConnection.setRequestProperty("User-Agent","NetFox"); -l ?\hmDl  
String sProperty = "bytes="+nStartPos+"-"; $8`"  
httpConnection.setRequestProperty("RANGE",sProperty); J$i.^|hE/  
Utility.log(sProperty); GezMqt;2  
^/~C\ (  
;),vUu,k  
InputStream input = httpConnection.getInputStream(); GQDW}b8  
//logResponseHead(httpConnection); A+hA'0isF@  
d fSj= 4  
1u~a*lO}  
byte[] b = new byte[1024]; 5em*9Ko  
int nRead; j7~Rw"(XQc  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e?+&2zMq  
{ ~W-5-Nl{s  
nStartPos += fileAccessI.write(b,0,nRead); 5 Q/yPQN  
//if(nThreadID == 1) %Ot*k%F  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }J $\<ZT  
} BT"n;L?[  
]Rj?OSok  
\k5 sdHmI[  
Utility.log("Thread " + nThreadID + " is over!"); C(kL=WD   
bDownOver = true; EkoT U#w5  
//nPos = fileAccessI.write (b,0,nRead); GOD{?#c$  
} [F 24xC+  
catch(Exception e){e.printStackTrace ();} g0#w 4rGF)  
} Q^):tO]!Ma  
} MH|R@g  
* 'Bu-1{  
i&j]FX6q  
//打印回应的头信息 =k5O*ql"  
public void logResponseHead(HttpURLConnection con) lYS*{i1^ '  
{ sQn@:Gk  
for(int i=1;;i++) =3dd1n;8>  
{ ANTWWs}  
String header=con.getHeaderFieldKey(i); 7m8(8$-6  
if(header!=null) eV j7%9  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6eb~Z6n&?  
Utility.log(header+" : "+con.getHeaderField(header)); fJ&\Z9zY  
else CW -[c  
break; F<DXPToX%  
} O]KQ]zN  
} _gw paAJ  
Qh+zs^-?  
vbfQy2q  
public void splitterStop() Z1{>"o:@  
{ o{3>n" \w3  
bStop = true; 0wt4C% .0  
} a|z@5r%  
mDO! o  
'xGTaKlm,  
} .R)uk  
51;[R8'w  
~SS3gLv  
/* *Tr9pq%m  
**FileAccess.java B +MnT{  
*//文件访问(定位,写) KxDp+]N]  
package NetFox; A Wd,qldv  
import java.io.*; Cv [1HO<  
nPk&/H%5hn  
d>V#?1$h  
public class FileAccessI implements Serializable{ F?t;bV  
 3Hi8=*  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6FY.kN\  
RandomAccessFile oSavedFile; lIPz "  
long nPos; ^U##9KkP  
LCW}1H:Q  
;,s9jw  
public FileAccessI() throws IOException hii#kB2  
{ C7K]c4T  
this("",0); Mbn;~tY>  
} -q\Rbb5M  
g.\%jDM  
ij1YV2v  
public FileAccessI(String sName,long nPos) throws IOException N_/+B]r }T  
{ {nw.bKq 7  
oSavedFile = new RandomAccessFile(sName,"rw"); W}#n.c4+  
this.nPos = nPos; wF3 MzN=%  
oSavedFile.seek(nPos); r"|.`$:B  
} C[5dhFZ  
^PUB~P/  
_fSBb<  
public synchronized int write(byte[] b,int nStart,int nLen) ]r'D  
{ (T%Ue2zlY  
int n = -1; h/6^>setz  
try{ + )[@  
oSavedFile.write(b,nStart,nLen); GWv i  
n = nLen; vM50H  
} [LO=k|&R  
catch(IOException e) %m+7$iD  
{ Vcnc=ct  
e.printStackTrace (); PkLNIp1  
} i[:cG  
#\_ 8y`{x  
]LEaoOecu  
return n; z#1"0Ks&P  
} 20}w . V  
sPXjU5uq#  
UZ#oaD8H6  
} Vf<q-3q  
;e< TEs  
%NM={X|'  
/* M&)\PbMc  
**SiteInfoBean.java _EJPI  
*/ 3_`)QYU'  
package NetFox; \0vs93>?  
!qU1RdZ  
N9*:]a  
public class SiteInfoBean { uP(t+}dQ+3  
IUNr<w<  
t#3 _M=L  
private String sSiteURL; //Site's URL |* ^LsuFb  
private String sFilePath; //Saved File's Path [A~ Hl  
private String sFileName; //Saved File's Name dMCoN8W  
private int nSplitter; //Count of Splited Downloading File 6P:fM Y  
0a bQY  
t=9f:,I$  
public SiteInfoBean() jsx&h Y%(  
{//nSplitter的缺省值为5 {&UA6 0~6  
//default value of nSplitter is 5 57=d;Yg e  
this("","","",5); K:GEC-  
} WIuYSt)h  
 g[bu9i  
:Z x|=  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v5@M 34  
{ s;Gg  
sSiteURL= sURL; )(_NFpM  
sFilePath = sPath; A=IpP}7J  
sFileName = sName; esj6=Gh  
this.nSplitter = nSpiltter; 2pU'&8  
DR,7rT{$  
dfKGO$}V  
} Ow.DBL)x'>  
r/HTkXs I  
5+;Mc[V3-  
public String getSSiteURL() IvlfX`("  
{ jM @N<k  
return sSiteURL; 0{ ~2mggh  
} C ocw%Yl  
VBw 5[  
t 7o4 aBl"  
public void setSSiteURL(String value) ZO/u3&gU  
{ W]bgWKd  
sSiteURL = value; x)GheM^  
} GM?s8yZ<  
aKWxLe  
^g5E&0a`g  
public String getSFilePath() 0zkMRBe  
{ {u2Zl7]z^  
return sFilePath; EmR82^_:  
} C=]<R< Xy  
MkL2I+*  
_> x}MW+  
public void setSFilePath(String value) 0y+^{@lU  
{ @!u{>!~0  
sFilePath = value; +L`}(yLJ)9  
} I:G8B5{J  
{-8Nq`w  
'Grii,  
public String getSFileName() ge:a{L  
{ &)gc{(4$  
return sFileName; =y_KL  
} )G Alj;9A$  
xr7}@rq"U<  
Dmr*Lh~  
public void setSFileName(String value) y_}vVHT,  
{ 1[8^JVC>6  
sFileName = value; i?;#Z Nh  
} s)`(@"{  
bxtH`^  
Qrg- xu=  
public int getNSplitter() At?|[%< `  
{ Q?1J<(oq9  
return nSplitter; {59 >U~  
} 4=/jh:h  
XsQ81j.  
 1n +Uv*  
public void setNSplitter(int nCount) Tx!t3;Yz[  
{ A|S)cr8z  
nSplitter = nCount; 6p*X8j3pW  
} rDhQ3iCqo  
} ?]$<Ufr  
Qn.dL@W  
&1yJrj9y  
/* 0NGth(2  
**Utility.java z k/`Uz  
*/ 6PYt>r&TO  
package NetFox; cWZITT{A  
tWTHyL  
#~)A#~4O  
public class Utility { _.Hj:nFHz  
`;+x\0@<  
*X/Vt$P  
public Utility() G3io!XM)D  
{ /MY's&D(  
vj%"x/TP  
{$hWz(  
} nPdkvs   
i.uyfV&F  
//线程睡眠 -d A9x~o  
public static void sleep(int nSecond) R/Bjc}J'  
{ $cHU,  
try{ kY\faWuR  
Thread.sleep(nSecond); DxNob-F r  
} 2Ax"X12{6  
catch(Exception e) Rw{' O]Q*  
{ z+7V}aPM  
e.printStackTrace (); bE.<vF&  
} 4@3\Ihv  
} *3`R W<Z  
H'zAMGZa  
//日志 #p>&|I  
public static void log(String sMsg) :?\29j#*V  
{ iYgVSVNg  
System.err.println(sMsg); RU7+$Z0K  
} q"<=^vi  
`e<IO_cg  
9dNkKMc@  
public static void log(int sMsg) SoM,o]s#y  
{ JxtzI2  
System.err.println(sMsg); <q$Tk,  
} 7HH@7vpJ^  
} }6\,kFc  
?V8Fgd  
XXum2eA  
/* 4"kc(J`c  
**TestMethod.java mc%. 8i  
*/ nUpj+F#  
package NetFox; Q4-d|  
e}yF2|0FD  
(0q`eO2  
public class TestMethod { z2YYxJ c&w  
!~9ASpqvPy  
O=7S=Rm4&  
public TestMethod() 3WF]%P%  
{ ///xx/weblogic60b2_win.exe n'^`;-  
try{ |.$B,cEd  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yKl^-%Uq<  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H!]&"V77  
SiteFileFetch fileFetch = new SiteFileFetch(bean); -%MXt  
fileFetch.start(); S8dfe~|7:  
} !7I07~&1  
catch(Exception e){e.printStackTrace ();} "[~yu* S  
]sb?lAxh{  
36(qe"s  
} &?bsBqpN  
_]o7iqtv  
X,l7>>L{g  
public static void main(String[] args) , 4xNW:!j  
{ 2[`n<R\  
new TestMethod(); DSRc4 |L  
} |e@1@q(a[]  
} $7Hwu^c(  
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