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http断点续传简单实现(java)

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/* OYfP!,+bn  
**SiteFileFetch.java L~M6 ca"  
*/ Gnqun%  
package NetFox; (j)>npOd9  
import java.io.*; <ot%>\C  
import java.net.*; :;3y^!  
FbPoyh  
g3w-Le&T  
public class SiteFileFetch extends Thread { s\ ]Rgi>w  
SP|Dz,o  
V+y:!t`  
SiteInfoBean siteInfoBean = null; //文件信息Bean wqn }t]  
long[] nStartPos; //开始位置 wGpw+O  
long[] nEndPos; //结束位置 y?s#pSX;N  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 l0wvWv*k  
long nFileLength; //文件长度 f;W>:`'  
boolean bFirst = true; //是否第一次取文件 ;cZ]^kof  
boolean bStop = false; //停止标志 bJ.68643  
File tmpFile; //文件下载的临时信息 ps]s Tw  
DataOutputStream output; //输出到文件的输出流 ])T_&%  
rI1;>/Ir  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }~Y#N  
public SiteFileFetch(SiteInfoBean bean) throws IOException JA?P jo  
{ WB|SXto%4D  
siteInfoBean = bean; 1'J|yq  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); w5&,AL:  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); "j+=py`  
if(tmpFile.exists ())  /I' np  
{ *j|BSd P  
bFirst = false; SR 1UO'.  
read_nPos(); 6n.C!,Zmn  
} "IsDL^)A9  
else NB/ wJ3 F  
{ A!5)$>!o  
nStartPos = new long[bean.getNSplitter()]; Z}6H529[  
nEndPos = new long[bean.getNSplitter()]; }"9jCxXL  
} L}U fd >*  
 W-U[7n  
$30lNZK1m8  
Y]1b3 9O  
} )e:u 6]  
sJ/?R:  
~%:23mIk  
public void run() DadlCEZv  
{ !~aDmY 2  
//获得文件长度 ~C],?X(zk  
//分割文件 7b[vZNi_  
//实例FileSplitterFetch :~]ha  
//启动FileSplitterFetch线程 ?)#}Nj<R  
//等待子线程返回 J\kv}v  
try{ "(#]H;!W  
if(bFirst) ,n?oNU  
{ `BHPj p>  
nFileLength = getFileSize(); DJhCe==$v  
if(nFileLength == -1) i(XqoR-x  
{ G8oOFBQD  
System.err.println("File Length is not known!"); i50^%,  
} 8MPXrc,9-  
else if(nFileLength == -2) {e8.E<f-  
{ +3D3[.n  
System.err.println("File is not access!"); s4c2  
} 7w{>bYP  
else PYz^9Ud 6g  
{ ra k@oW]  
for(int i=0;i<nStartPos.length;i++) kC)ye"r  
{ u=h/l!lR  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); W.u}Q@  
} Gv w:h9v  
for(int i=0;i<nEndPos.length-1;i++) eu|cQ^>  
{ Y/_b~Ahn  
nEndPos = nStartPos[i+1]; IGd]!  
} BI-xo}KI  
nEndPos[nEndPos.length-1] = nFileLength; @{!c [{x,T  
} 'Nv*ePz  
} J@c)SK%2h  
k:0HsN!F9  
\{[Gdj`  
//启动子线程 <M|kOi  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ca1A9fvo  
for(int i=0;i<nStartPos.length;i++) AA$-Lx(UJk  
{ RE(R5n28,  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u%vq<|~-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), PNn{Rt  
nStartPos,nEndPos,i); BK8)'9/  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e" f/  
fileSplitterFetch.start(); ^H1B 62_  
} 8D U|j-I8  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zg/ra1n  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'J&$L c  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P'6eK?  
nEndPos = " + nFileLength); ?_9A`LC*  
// fileSplitterFetch[nPos.length-1].start(); kN*,3)T;}  
4c*?9r@  
w QX,a;Br  
//等待子线程结束 -*u7MFq_  
//int count = 0; /=}w%-;/;  
//是否结束while循环 L}1|R*b  
boolean breakWhile = false; >>voLDDd  
@exeHcW61  
gZe(aGh  
while(!bStop) *94<rlh{"  
{ #B3P3\  
write_nPos(); x_vaYUl)  
Utility.sleep(500); 4jl UyAD  
breakWhile = true; Vs)Pg\B?  
#?Z>o16,u  
 ((}T^  
for(int i=0;i<nStartPos.length;i++) tN=B9bm3j  
{ Wi Mi0?$.  
if(!fileSplitterFetch.bDownOver) p#UrZKR  
{ ?[}r& f  
breakWhile = false; ~e5hfZv|w  
break; e:E:"elr]  
} c-L1 Bkw  
} B6&;nU>;  
if(breakWhile) Pvq74?an`  
break; %o4ZD7@ '  
Pwn3/+"%K  
l.c*, 9  
//count++; >weY_%a  
//if(count>4) |#);^z_  
// siteStop(); P\B ]><!ep  
} #MbkU])  
F/FUKXxx  
I5l5fx  
System.err.println("文件下载结束!"); 'a`cK;X9F  
} YQWGv,47\  
catch(Exception e){e.printStackTrace ();} ab5 a>w6}  
} XjL)WgQ{i  
dBKL_'@@}  
KErQCBeJ  
//获得文件长度 d|!FI/  
public long getFileSize() d7.}=E.L  
{ r5kKNyJ  
int nFileLength = -1;  x w8 e  
try{ S: IhJQ4K  
URL url = new URL(siteInfoBean.getSSiteURL()); cRm+?/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3xSt -MA  
httpConnection.setRequestProperty("User-Agent","NetFox"); -\OvOkr  
fz[o;GTc  
kQ5mIJ9(  
int responseCode=httpConnection.getResponseCode(); 5\MCk"R!  
if(responseCode>=400) E-Nc|A  
{ kcg{z8cd'r  
processErrorCode(responseCode); zO BLF|L=  
return -2; //-2 represent access is error e5/f%4YX  
} `52+.*J+%  
+yvtd]D$2W  
P;7JK=~k  
String sHeader; q#RUL!WF7U  
lxIo P  
s9R#rwIc  
for(int i=1;;i++) I d6H~;  
{ OIpkXM  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,Jm2|WKH  
//Utility.log(in.readLine()); jlvh'y`  
sHeader=httpConnection.getHeaderFieldKey(i); ' U]\]Wp  
if(sHeader!=null) @]v}& j7  
{ (gY3?&Ok*  
if(sHeader.equals("Content-Length")) ~:`5Y"Av:  
{ EDQKbTaPt  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !6Sr*a*5  
break; F xek#  
} |$*1!pL-QP  
} or~2r8  
else LhN?j5XqM  
break; 3q'["SS  
} *$K_Tii  
} b.mcP@  
catch(IOException e){e.printStackTrace ();} 87; E#2  
catch(Exception e){e.printStackTrace ();} 2a=3->D&  
us j:I`>  
RLy(Wz3%  
Utility.log(nFileLength); -|0nZ  
`1}WQS  
aQjs5RbP~  
return nFileLength; CD}::7$  
} 6_Ps*Ed  
,%)O/{p_  
&8p]yo2zO  
//保存下载信息(文件指针位置) _yH{LUIj  
private void write_nPos() =E6ND8l@2  
{ +,7nsWV  
try{ yx0wR  
output = new DataOutputStream(new FileOutputStream(tmpFile)); O;zq(/,-l  
output.writeInt(nStartPos.length); I5#KLZVg  
for(int i=0;i<nStartPos.length;i++) .|\}] O`  
{ cQg:yoF  
// output.writeLong(nPos); 'q3<R%^Q   
output.writeLong(fileSplitterFetch.nStartPos); _C`&(?}  
output.writeLong(fileSplitterFetch.nEndPos); z$64Ep#  
} WP5cC@x  
output.close(); JVfSmxy.  
} J,iS<lV_  
catch(IOException e){e.printStackTrace ();} F ru&-T[  
catch(Exception e){e.printStackTrace ();} ?3[Gh9g`  
} <}uhKp>*  
,7HlYPec  
-!o*A>N  
//读取保存的下载信息(文件指针位置) N>pTl$\4  
private void read_nPos() (G1KMy  
{ 8jBrD1  
try{ @:,B /B;  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f.yvKi.Cm  
int nCount = input.readInt(); k^VL{z:EWB  
nStartPos = new long[nCount]; ,> Ya%;h2k  
nEndPos = new long[nCount]; zR@4Z>6   
for(int i=0;i<nStartPos.length;i++) pc/x&VY%  
{ \#50; 8VJ  
nStartPos = input.readLong(); xG_LEk( zD  
nEndPos = input.readLong(); [ TX1\*W  
} $6[%NQp  
input.close(); 91f{qq=#J{  
} 4{PN9i E  
catch(IOException e){e.printStackTrace ();} O)N$nBnp  
catch(Exception e){e.printStackTrace ();} ,xSNTOJ  
} "A( D}~i  
PiwMl)E|!  
53X i)  
private void processErrorCode(int nErrorCode) u~O9"-m !V  
{ 9%#u,I  
System.err.println("Error Code : " + nErrorCode); Rb/|ae  
} ^X]rFY1  
NqlU?  
_xWX/1DY  
//停止文件下载 Ez1-Nx  
public void siteStop() ylGT9G19  
{ 3VZ}5  
bStop = true; 14~#k%zO(  
for(int i=0;i<nStartPos.length;i++) j.]ln}b/'+  
fileSplitterFetch.splitterStop(); AU$<W"%R  
tDC?St1  
at|.Q*&a#  
} ;S_Imf0$v  
} iv!;gMco  
//负责部分文件的抓取 O#_\@f#[  
**FileSplitterFetch.java c9ye[81  
*/ ge#0Q L0K  
package NetFox; 5)c B\N1u  
"F[e~S#V*  
#x+7-hi  
import java.io.*; >b7Yk)[%  
import java.net.*; xe4`D>LUo  
9^?2{aP%  
SuR+Vv  
public class FileSplitterFetch extends Thread { d53Eu`QW?  
+@^FUt=tq  
: uxJGx  
String sURL; //File URL sC'PtFK8z  
long nStartPos; //File Snippet Start Position +xL' LC x  
long nEndPos; //File Snippet End Position u<U8LR=)V5  
int nThreadID; //Thread's ID !#Pr'm/,mu  
boolean bDownOver = false; //Downing is over Cl8S_Bz  
boolean bStop = false; //Stop identical o$p] p9  
FileAccessI fileAccessI = null; //File Access interface +;Pkpuu  
*b4W+E  
Z!+n/ D-1  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /B 53Z[yL  
{ 1rIL[(r4  
this.sURL = sURL; GU0[K#%  
this.nStartPos = nStart; w-"tA`F4  
this.nEndPos = nEnd; Q<Q?#v7NX  
nThreadID = id; 0 wjL=]X1e  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'u#c_m! 9  
} 5oe{i/#di  
F2>W{-H+  
 \4j(el  
public void run() D!DL6l`  
{ P(b ds  
while(nStartPos < nEndPos && !bStop) 84_Y+_9  
{ \IhHbcF`d  
;uho.)%N`F  
-]Ny-[P  
try{ yJ:rry  
URL url = new URL(sURL); :-Wh'H(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HPY;U N  
httpConnection.setRequestProperty("User-Agent","NetFox"); gXj3=N(l  
String sProperty = "bytes="+nStartPos+"-"; j.yh>"de  
httpConnection.setRequestProperty("RANGE",sProperty); 84lT# ^q  
Utility.log(sProperty); &s{d r  
U6F7dT  
3>v-,S+  
InputStream input = httpConnection.getInputStream(); y&A&d-  
//logResponseHead(httpConnection); {(IHHA>  
3V]08  
mhMTn*9  
byte[] b = new byte[1024]; Doe:m#aNj  
int nRead; pK"iTc#\X  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @x^/X8c(p  
{ ro+8d  
nStartPos += fileAccessI.write(b,0,nRead); U UhlKV|5  
//if(nThreadID == 1) D/ tCB-+  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |&MO us#v  
} z.!u<hy(  
b5#Jo2C`AJ  
lot;d3}  
Utility.log("Thread " + nThreadID + " is over!"); YIs_.CTi  
bDownOver = true; 3F8K F`*  
//nPos = fileAccessI.write (b,0,nRead); l>T]Y  
} v"*c\,  
catch(Exception e){e.printStackTrace ();} Byh!Snoe  
} OWp`Wat  
} E&ReQgBft  
-nZDFC8y$  
v\g1 w&PN  
//打印回应的头信息 EeQ2\'t  
public void logResponseHead(HttpURLConnection con) w0O(>  
{ _&M^}||UH  
for(int i=1;;i++) yBCLS550  
{ U J uz  
String header=con.getHeaderFieldKey(i); ezA&cZ5  
if(header!=null) ,b<m],p  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mYqLqezAA  
Utility.log(header+" : "+con.getHeaderField(header)); A>f rf[fAW  
else *|^|| bd  
break; U1D;O}z~  
} Z-L}"~  
} ~ %Ij5PD  
Z6nQW53-  
y:Agmr,S  
public void splitterStop() Ih[k{p  
{ ltv ~Kh  
bStop = true; ~i]4~bkH2  
} It]GlxMX  
^}UFtL i  
j>5X^Jd  
} %v0;1m  
";upu  
w3;T]R*  
/* |+Xh ^E  
**FileAccess.java hbSKlb0d  
*//文件访问(定位,写) Of-8n-  
package NetFox; 94?/Rhs5  
import java.io.*; h(i_'P?  
8g?2( MT;  
Lie= DD  
public class FileAccessI implements Serializable{ `,Fc271`  
TpYdIt9#>  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T#KVN{O  
RandomAccessFile oSavedFile; ~ymSsoD^  
long nPos; J&L#^f*d  
55Xfu/hQ  
Xif>ZL?aXb  
public FileAccessI() throws IOException 3x=NSe|f  
{ L% T%6p_  
this("",0); [KMS/'; ]  
} `j'gt&  
id)J;!^;J  
keJ-ohv)  
public FileAccessI(String sName,long nPos) throws IOException eI@G B  
{ P!!:p2fo  
oSavedFile = new RandomAccessFile(sName,"rw"); JHuA}f{2&  
this.nPos = nPos; [4-u{Tu  
oSavedFile.seek(nPos); Jmu oYlf|  
} g@m__   
@2eH;?uO  
+D?Re%HI  
public synchronized int write(byte[] b,int nStart,int nLen) 6?-,@e  
{ `a8&7 J(  
int n = -1; 9 1ec^g  
try{ 1]aya(  
oSavedFile.write(b,nStart,nLen); ,w,)n^  
n = nLen; +$R%Vbd  
} _@Y17L.  
catch(IOException e) LbnF8tj}h  
{ 'EB5#  
e.printStackTrace (); 0{u#{_  
} ^t[br6G  
2\#~%D>[  
xw3A|Aj?r  
return n; XeozRfk%J|  
} 787}s`,}  
{ /Gm|*e{  
 W|6.gN]  
} lAAPV  
^3nB2G.ax  
nz`"f,  
/* Y|<1|wGG  
**SiteInfoBean.java ROj=XM:+  
*/ o2^?D`Jr  
package NetFox; F5<GGEQb  
_p| KaT``  
'~76Y9mv  
public class SiteInfoBean { [jF\"#A  
$I a-go2W  
^Y^5 @ x=  
private String sSiteURL; //Site's URL NTSKmCvQG  
private String sFilePath; //Saved File's Path HgRfMiC  
private String sFileName; //Saved File's Name ]2xoeNF/W{  
private int nSplitter; //Count of Splited Downloading File {N0ky=u d  
[,qb) &_  
DO? bJ01  
public SiteInfoBean() =e]Wt/AQ  
{//nSplitter的缺省值为5 1F?ylZ|~  
//default value of nSplitter is 5 8;P_KRaE  
this("","","",5); _1?Fy u&<5  
} mGUl/.;yp-  
r<.*:]L  
=_d-MJy~6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C5oIl_t  
{ :w4I+* ]  
sSiteURL= sURL; z|G 39  
sFilePath = sPath; .w)T2(  
sFileName = sName; Jm}zit:o  
this.nSplitter = nSpiltter; @_Ly^' "  
Ox f,2r  
h_h6@/1l  
} 0"M0tA#  
^i~'aq  
1H,hw  
public String getSSiteURL() 2n5{H fpY  
{ U_e e3KKA  
return sSiteURL; p%*! ]JRS  
} 7 m!e\x8  
_Y,d|!B#L  
d:=:l?  
public void setSSiteURL(String value) 2BIOA#@t  
{ veGRwir  
sSiteURL = value; ]i pltR7k  
} V %Rz(a+c  
pi?U|&.1z  
-\=kd {*B  
public String getSFilePath() Gnmxp%&}P|  
{ Yim`3>#t  
return sFilePath; eVy\)dCsU  
} ]#oqum@Yf1  
(#k2S-5  
^7% KS  
public void setSFilePath(String value) B\Y !5$  
{ S#, E)h/  
sFilePath = value; f<G:}I  
} )haHI)xR  
w`OHNwXh#I  
oGi{d5  
public String getSFileName() 3:WXrOl  
{ qbe9 CF'@_  
return sFileName; c6)q(zz  
} : S |)  
K.jm>]'z4;  
ceqYyVy  
public void setSFileName(String value) K-*q3oh G  
{ rhe;j//`  
sFileName = value; c\pPwG  
} H@xIAL  
c/E6}OWA  
VR9C< tMSi  
public int getNSplitter() ua vv  
{ }nJG<rY  
return nSplitter; &D~70N\L  
} ,*@6NK,.  
p#dpDjh  
 ,M&[c|  
public void setNSplitter(int nCount) tJ9i{TS  
{ r-a/vx#  
nSplitter = nCount; j/xL+Y(=  
}  !(<Yc5  
} <C_FI` wk  
#wZ:E,R  
K) "cwk-  
/* hol54)7$3:  
**Utility.java Ng3MfbFG  
*/ UN}jpu<h  
package NetFox; xdH*[  
Pc4FEH/  
glppb$oB\  
public class Utility { G&Sp }  
RT)*H>|  
T+[N-"N  
public Utility() j@b4)t  
{ *:}NS8hP  
O5Xu(q5+  
{^#62Y  
} x1kb]0s<-  
eOQUy +  
//线程睡眠 kEE8cW3  
public static void sleep(int nSecond) \}e1\MiZ  
{ dEp?jJP$;  
try{ +)fl9>Mb  
Thread.sleep(nSecond); !:mo2zA  
} 0VB~4NNR  
catch(Exception e) rs R0V+(W  
{ !s]LWCX+|  
e.printStackTrace (); QMfa~TH#p  
} j[h4F"`-  
} r^k:$wJbRK  
5Qik{cWxBq  
//日志 GiN\nu<!  
public static void log(String sMsg) ccJ@jpXI  
{ #U NTD4   
System.err.println(sMsg); TK;*:K8oe  
} <"@~  
Nd~?kZZu  
%Y` @>P'  
public static void log(int sMsg) %jY /jp=R  
{ !z;a>[T'  
System.err.println(sMsg); i(JBBE"  
} _e=R[  
} tw]RH(g+#  
cRX0i;zag  
|.Bb Pfe8f  
/* oO|zRK1;/  
**TestMethod.java gaC^<\J  
*/ u><gmp&  
package NetFox; ,iU ]zN//  
HZdmL-1Z^+  
m[C-/f^u|  
public class TestMethod { */n)_  
+!V*{<K  
/)xG%J7H  
public TestMethod() [BHf>  
{ ///xx/weblogic60b2_win.exe Mrp'wF D  
try{ 8Z!+1b  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k|,pj^  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @#}9?>UV  
SiteFileFetch fileFetch = new SiteFileFetch(bean); FG-w7a2mn  
fileFetch.start(); Nf>1`eP  
} 02} &h  
catch(Exception e){e.printStackTrace ();} A}sb 2P  
$L.0$-je4  
m El*{]  
} IEdC _6G  
|*7uF<ink6  
a8-2:8Su  
public static void main(String[] args) t#~r'5va  
{ !Ljs9 =UF  
new TestMethod(); #:Di1I9<O7  
} |$":7)e H!  
} AU}P`fT!  
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