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http断点续传简单实现(java)

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/* `!D s6  
**SiteFileFetch.java v-yde >(  
*/ $-#Yl&?z9  
package NetFox; 58%#DX34M  
import java.io.*; S:TgFt0  
import java.net.*; e*@{%S  
A-,up{g  
Zm=(+ f  
public class SiteFileFetch extends Thread { (>`5z(X  
 `)GrwfC  
~=8uN<  
SiteInfoBean siteInfoBean = null; //文件信息Bean {Zh>mHW3  
long[] nStartPos; //开始位置 G 16!eDMt  
long[] nEndPos; //结束位置 6&bY}i^K  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 /%0<p,T  
long nFileLength; //文件长度 qHNE8\9  
boolean bFirst = true; //是否第一次取文件 6)vSG7Ise  
boolean bStop = false; //停止标志 R  zf  
File tmpFile; //文件下载的临时信息 ua5OGx  
DataOutputStream output; //输出到文件的输出流 Kv.>Vf.T}_  
.so[I  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) jy giG&H  
public SiteFileFetch(SiteInfoBean bean) throws IOException Qtbbb3m;  
{ Ku\Y'ub  
siteInfoBean = bean; 6U[4%(  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ;QW3CEaUq  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); UlAzJO6"  
if(tmpFile.exists ()) qZ}P*+`Q  
{ deM7fN4lTi  
bFirst = false; aYuD>rD  
read_nPos(); %z#f.Ql  
} = M]iIWQ@`  
else UB 6mqjPK  
{ K'X2dG*  
nStartPos = new long[bean.getNSplitter()]; A5i:x$ww  
nEndPos = new long[bean.getNSplitter()]; ~zSCg|"r  
} @+9<O0  
%^1cyk  
]u4Hk?j~<  
K_2|_MLlZ  
} EL8NZ%:v:  
yaG= j  
 .&9 i  
public void run() ]8T |f  
{ hQ(qbt{e  
//获得文件长度 :6zG7qES3  
//分割文件 %{/%mJoX  
//实例FileSplitterFetch Eh =~T9  
//启动FileSplitterFetch线程 *+uHQgn(  
//等待子线程返回 3&6#F"7  
try{ P>sFV  
if(bFirst) +T=(6dr  
{ &g.@u~SI1  
nFileLength = getFileSize(); C4hx@abA  
if(nFileLength == -1) wE@'ap#  
{ )(tM/r4`c&  
System.err.println("File Length is not known!"); TQ`Rk;0R  
} LJOr!rWi  
else if(nFileLength == -2) UTf9S>HS  
{ #]#sGmW/L  
System.err.println("File is not access!"); "TUe%o  
} Kx=4~  
else G!Um,U/g  
{ 7UL qo>j  
for(int i=0;i<nStartPos.length;i++) -K rxMi  
{ [Z~ 2  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ithewup  
} nPs7c %  
for(int i=0;i<nEndPos.length-1;i++) /F4pb]U!*  
{ 81hbk((  
nEndPos = nStartPos[i+1]; .\8X[%K9nc  
} y_HN6  
nEndPos[nEndPos.length-1] = nFileLength; T"&)&"W*U  
} FL8g5I  
} ^Ve<>b  
esHQoIhd  
0TmR/uUT  
//启动子线程 "Ae@lINn[y  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WBNw~|DO]  
for(int i=0;i<nStartPos.length;i++) >0dv+8Mn  
{ qwK2WE%T  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MY/3] g<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .[Ap=UYI>  
nStartPos,nEndPos,i); +=]!P#  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (`6T&>(4  
fileSplitterFetch.start(); 9elga"4:'  
} OKi\zS  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k6Uc3O  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u ~3%bJ]  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vk>b#%1{  
nEndPos = " + nFileLength); l#lF +Q;  
// fileSplitterFetch[nPos.length-1].start(); &q`q4g&7  
A8q;q2  
2MATpV#BT  
//等待子线程结束 0vVV%,v  
//int count = 0; bJYda)  
//是否结束while循环 P ~#>H{  
boolean breakWhile = false; w,O,W[C  
%0$qP0|`3I  
Q2A7mGN  
while(!bStop) i~3u>CT  
{ 3d-%>?-ee  
write_nPos(); DhX#E&  
Utility.sleep(500); ,o^y`l   
breakWhile = true; {t Thy#  
M;0]u.D*=  
fZxIY,  
for(int i=0;i<nStartPos.length;i++) U,+[5sbo  
{ v^ /Q 8Q  
if(!fileSplitterFetch.bDownOver) Fbu5PWhlc  
{ RN)dS>$  
breakWhile = false; 3SSm5{197  
break; 4;HJ;0-ps  
} }lK3-2Pk  
} 4GR!y)  
if(breakWhile) ->h6j  
break; /'Pd`Nxl.  
7HVZZ!>~  
9}c8Xt^&  
//count++; 3:{yJdpg  
//if(count>4) %lX%8Z$v  
// siteStop(); k"g._|G  
} -QyhwG =  
CiR%Ujf  
sHcTd>xS  
System.err.println("文件下载结束!"); ]`bQW?  
} MWNPPYww  
catch(Exception e){e.printStackTrace ();} 11|Rdd+}  
}  PlYm&  
L{E^?iX  
wBQF~WY  
//获得文件长度 * ,v|y6  
public long getFileSize() jqH3J2L  
{ U:MPgtwe  
int nFileLength = -1; G60R9y47c  
try{ @Kf_z5tm:  
URL url = new URL(siteInfoBean.getSSiteURL()); hLDA]s  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XyMG.r-,  
httpConnection.setRequestProperty("User-Agent","NetFox"); RUr=fEH  
[]0mX70N  
DAg58 =qJ  
int responseCode=httpConnection.getResponseCode(); RNPbH.  
if(responseCode>=400) N$x tHtz8"  
{ 7~ztwL  
processErrorCode(responseCode); +fx8muz:y  
return -2; //-2 represent access is error PyA&ZkX>  
} ^1Xt]T`e  
m=Q[\.Ra  
<*t4D-os  
String sHeader; l88A=iLgv  
kD) $2I?  
}pa9%BQI  
for(int i=1;;i++) v`V7OD#:j]  
{ l;sy0S"DO]  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >a1{397Y}  
//Utility.log(in.readLine()); ;. wX@  
sHeader=httpConnection.getHeaderFieldKey(i); n6(i`{i  
if(sHeader!=null) /%A;mlf{  
{ M(d6Z2ibh  
if(sHeader.equals("Content-Length")) '!P"xBVAu  
{ YUQtMf9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hUz[uyt  
break; N$TL;T>  
} ;pD)m/$h`  
} htm{!Z]s0  
else q> s-Y|  
break; h;V,n  
} w[_x(Ojq;  
} =SD\Q!fA  
catch(IOException e){e.printStackTrace ();} y fSM  
catch(Exception e){e.printStackTrace ();} WZ!WxX>zO  
0t#g }  
]O{u tm  
Utility.log(nFileLength); "+?Cz !i   
okq[ o90  
\V2,pi8'v  
return nFileLength; g\GdkiIj  
} I _i6-<c.Q  
M HL("v(@B  
tn|,O.t  
//保存下载信息(文件指针位置) s cdtWA  
private void write_nPos() 7([h4bg{  
{ 0)Rw|(Fpo]  
try{ =2y8 CgLj  
output = new DataOutputStream(new FileOutputStream(tmpFile)); \n9A^v`F/  
output.writeInt(nStartPos.length); F8e<}v&7R  
for(int i=0;i<nStartPos.length;i++) xt4)Ya  
{ fag^7rz  
// output.writeLong(nPos); 7n)&FX K`  
output.writeLong(fileSplitterFetch.nStartPos); Q,Z*8FH=  
output.writeLong(fileSplitterFetch.nEndPos); `(0LK%w  
} bXYA5wG  
output.close();  ==/n(LBD  
} $jI>[%  
catch(IOException e){e.printStackTrace ();} TP1S[`nR  
catch(Exception e){e.printStackTrace ();} Gjz[1d  
} Sd IX-k.  
BpO9As 1um  
ZyR_6n>L$  
//读取保存的下载信息(文件指针位置) z"DkFvA  
private void read_nPos() # x>ga  
{ I\\QS.2  
try{ Sx ] T/xq  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gQ~5M'#  
int nCount = input.readInt(); . BO<  
nStartPos = new long[nCount]; lH|LdlX  
nEndPos = new long[nCount]; 7:h!Wj -a]  
for(int i=0;i<nStartPos.length;i++) ?IX!+>.H  
{ ^TXfsQs  
nStartPos = input.readLong(); 92dF`sv  
nEndPos = input.readLong(); 1u]P4Gf=  
} vMSW$Bx ;  
input.close(); |0bc$ZY:  
} <Y'>F!?#  
catch(IOException e){e.printStackTrace ();} v| z08\a[  
catch(Exception e){e.printStackTrace ();} A%Z)wz{  
} V'Qn sI  
$e\N+~KNCy  
%@ mGK8  
private void processErrorCode(int nErrorCode) i(2y:U3[@  
{ v7trr W}  
System.err.println("Error Code : " + nErrorCode); {bF1\S]2  
} &h$|j  
Y9r3XhVI  
daZQz"PP  
//停止文件下载 )_jSG5k  
public void siteStop() =Pe><k  
{ ED![^=  
bStop = true; ARh6V&Hi-  
for(int i=0;i<nStartPos.length;i++) w#G2-?aj  
fileSplitterFetch.splitterStop(); KA]*ox6j;  
yno('1B@  
E@QA".  
} 6k])KlJ2;  
} 4ax|Vb)D  
//负责部分文件的抓取  W^g[L:s  
**FileSplitterFetch.java w,.qCpT$_  
*/ !UV5zmS  
package NetFox; N:+ taz-  
fW0$s`  
/k:$l9C[  
import java.io.*; 83 ]PA<R  
import java.net.*; 'bW5Fr>W  
b_$ 1f >  
qFR dg V>8  
public class FileSplitterFetch extends Thread { 1 H4fJ3-  
y@vj;3:  
Q]JX`HgPaU  
String sURL; //File URL &hZwZgV +3  
long nStartPos; //File Snippet Start Position ?Z %:  
long nEndPos; //File Snippet End Position p5 ]_}I`+2  
int nThreadID; //Thread's ID BQgoVnQo_c  
boolean bDownOver = false; //Downing is over {_ V0  
boolean bStop = false; //Stop identical "/x_>ui1F  
FileAccessI fileAccessI = null; //File Access interface LZ~`29qw(  
~o15#Pfn/  
T|'&K:[TJ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b#Kq[}  
{ (wt+`_6  
this.sURL = sURL; k{Lv37H  
this.nStartPos = nStart; *:_~Nn9_R;  
this.nEndPos = nEnd; W=-|`  
nThreadID = id; OHp5z? z  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R"6;NPeo  
} 2z2`  
=fG:A(v%}  
J=WB6zi  
public void run() 2:v<qX  
{ 4L:>4X[T  
while(nStartPos < nEndPos && !bStop) z%"Ai)W/{  
{ \SYvD y]  
LPE)  
"G?9b  
try{ oh}^?p  
URL url = new URL(sURL); ,jh~;, w2  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *v #/Y9}  
httpConnection.setRequestProperty("User-Agent","NetFox"); \aSz2lxEHn  
String sProperty = "bytes="+nStartPos+"-"; ZCiY,;c  
httpConnection.setRequestProperty("RANGE",sProperty); oKKz4  
Utility.log(sProperty); Pern*x9$  
{sc[RRN~C  
h W.2p+  
InputStream input = httpConnection.getInputStream(); .|]IwyD &  
//logResponseHead(httpConnection); $B _Nc*_e  
T1~)^qQ  
>A jCl  
byte[] b = new byte[1024]; !EFBI+?&  
int nRead; y lL8+7W  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |>utWT]S  
{ 9Q[>.):  
nStartPos += fileAccessI.write(b,0,nRead); k ojG- M  
//if(nThreadID == 1) r,'O ).7  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /7p>7q 9g  
} #( uj$[o  
<'*4j\*  
qZ\ L  
Utility.log("Thread " + nThreadID + " is over!"); @ ^. *$E5  
bDownOver = true; Ml`vx  
//nPos = fileAccessI.write (b,0,nRead); %8D?$v"#Z  
} 1X@b?6  
catch(Exception e){e.printStackTrace ();} A@ VaaX  
} @l>Xnqx)  
} 8R/ *6S=&  
7*'@qjTos  
rWr/p^~  
//打印回应的头信息 vgk9b!Xd  
public void logResponseHead(HttpURLConnection con) euZ(}+N&  
{ ?`. XK}  
for(int i=1;;i++) M_&4]\PkCy  
{ =~,l4g\  
String header=con.getHeaderFieldKey(i); n6cq\@~A  
if(header!=null) &>=#w"skb6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BJIQ zn3  
Utility.log(header+" : "+con.getHeaderField(header)); 0zV 4`y  
else |cu`f{E2]  
break; wgZrrq/W|  
} 3j&B(aLy  
} 'G Y/Q5  
8A/>JD3^  
;Q90Y&{L=$  
public void splitterStop() TcZN %  
{ H-a^BZ&iU  
bStop = true; -A;w$j6*  
} "^"'uO$  
@XBH.A^7r  
 q)oN 2-  
} E\! n49  
!3x *k;0  
+S0u=u65  
/* ,>w}xWSYpG  
**FileAccess.java pzSqbgfrQ  
*//文件访问(定位,写) + (=I8s/  
package NetFox; 1*c>I@I;  
import java.io.*; |Mlh;  
)k~1,  
=h[yA f  
public class FileAccessI implements Serializable{ @YB85p"]J.  
u_Zm1*'?B  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -$L(y@%X^  
RandomAccessFile oSavedFile; X 7&U3v  
long nPos; @ RX`>r{_  
|D(&w+(  
*[ #*n n  
public FileAccessI() throws IOException ^Y<M~K972  
{ ?%;B`2 nDR  
this("",0); L5C2ng>  
} w .l|G,%=  
o'^phlX  
Z"N(=B  
public FileAccessI(String sName,long nPos) throws IOException x _|>n<Z  
{ qOgtGN}k  
oSavedFile = new RandomAccessFile(sName,"rw"); bQV("~#  
this.nPos = nPos;  2$)mC9  
oSavedFile.seek(nPos); 1gk0l'.z  
} x Ty7lfSe  
PvuAg(?  
*k [kV  
public synchronized int write(byte[] b,int nStart,int nLen) _Z.;u0Zp8  
{ khS/'b  
int n = -1; /x O{ .dr  
try{ Vku#;:yUb^  
oSavedFile.write(b,nStart,nLen); p_gA/. v=  
n = nLen; PS/W h  
} -;<>tq'3`  
catch(IOException e) i\vpGlx  
{ Z?C4a }  
e.printStackTrace (); w Oj88J)  
} &58 {  
V0S6M^\DK  
Z !Z,M' "  
return n; F`3^wHw^  
} +i4P,Lp  
$>(9~Yh0  
*bU% @O  
} ik1XGFy?  
15JsmA*Q  
<B=[hk!  
/* {9Xm<}%u]]  
**SiteInfoBean.java *f?S5 .  
*/ o[n<M> @  
package NetFox; qr9Imr0w<  
!^]q0x  
+#9xA6,AE  
public class SiteInfoBean { {sl~2#,}b1  
avV mY|I  
wn{]#n=|l  
private String sSiteURL; //Site's URL InP[yFV-z  
private String sFilePath; //Saved File's Path ~@?"' !U  
private String sFileName; //Saved File's Name ,,Jjr[A_j  
private int nSplitter; //Count of Splited Downloading File /[6:LnaE  
[~!.a\[RW  
,5=kDw2  
public SiteInfoBean() e7lo!( >#  
{//nSplitter的缺省值为5 .@Hmg  
//default value of nSplitter is 5 a" ^#!G<+  
this("","","",5); TG4^_nRl  
} gh'kUZG a  
89db5Dx  
LH,]vuXh  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E`(5UF*>  
{ @|E;}:?u  
sSiteURL= sURL; Lp!0H `L  
sFilePath = sPath; R !Fx)xj  
sFileName = sName; Kyu@>9Ok  
this.nSplitter = nSpiltter; ,cPkx~w0  
[6G=yp  
{uEu >D$8  
} Z 4\tY^NI  
+{ S Maq  
%l%=Dkss  
public String getSSiteURL() 6W]OpM  
{ QN3 qF|))  
return sSiteURL; \)p4okpR  
} ^4RO  
<|B$dz?r  
Tm%WWbc  
public void setSSiteURL(String value) aD?# ,  
{ ;,mBT[_ZO  
sSiteURL = value; %Fs*#S  
} K?$ 9N}+  
a^%8QJW  
^dheJ]n=k  
public String getSFilePath() [y_yPOv  
{ /4(Z`e;0  
return sFilePath; 'lxLnX  
} }!eF  
\moZ6J  
!p-'t]  
public void setSFilePath(String value) ~wa%fM  
{ p .lu4  
sFilePath = value; qK{| Q  
} ?OdV1xB  
b=V)?"e-  
CM`x>J  
public String getSFileName() RA#\x.  
{ {bW"~_6}  
return sFileName; qw6EPC  
} Q -M rH   
7ytm .lU  
.L~fFns/  
public void setSFileName(String value) n'! -Pv  
{ O)Xd3w'  
sFileName = value; k,a,h^{}j  
} Lr K9F^c  
"1_{c *ck  
yW%&_s0  
public int getNSplitter() >oVc5}  
{ zC<'fT/rG  
return nSplitter; M|1eqR%x-?  
} N5[_a/  
&*X3c h  
(PRaiE  
public void setNSplitter(int nCount) s4!|v`+$M  
{ H?rSP0.  
nSplitter = nCount; cZPbD;e:  
} cjCE3V9X  
} zG& WWc`K  
[6Uudiw  
QWU5-p9e8  
/* bv.EM  
**Utility.java ON:LPf>"-  
*/ 8yY"x ['  
package NetFox; jXc5fXO N  
c2tEz&=G  
L-^# 02  
public class Utility {  Bq~AU#  
\W3+VG2cA  
s#'|{  
public Utility() 43UJ#rF  
{ bx+(.F  
NTXws4'D  
{Bav$kw;?e  
} wJ;9),fL  
J`U$b+q6  
//线程睡眠 =g{_^^n  
public static void sleep(int nSecond) F2Nb5WT  
{ #R~">g:w  
try{ g_3rEvf"4  
Thread.sleep(nSecond); O JZ!|J8?  
} pkrl@ jv >  
catch(Exception e) f]@[4<Ny  
{ !Ei Ze.K  
e.printStackTrace (); AlPL;^Y_l  
} O^QR;<t'  
} P^'>dOI0w  
\#h})`  
//日志 `D&#U'wB   
public static void log(String sMsg) Bbn832iMUY  
{ #o(?g-3  
System.err.println(sMsg); *!-}lc^4  
} h$#4ebp  
(.jO:#eE%  
?^e*UJNM  
public static void log(int sMsg)  e B9m4  
{ ;XD>$t@  
System.err.println(sMsg); IqR[&T)lj  
} :X1`wBu  
} xEd#~`Jmr  
mI{CM: :  
.#:@cP~v  
/* r9p?@P\:[  
**TestMethod.java g7E`;&f  
*/ ONg<  
package NetFox; ~m,mvRS  
\? 5[RR  
JCCx 5  
public class TestMethod { :O>Nd\UtO  
z9OMC$,V  
K-g=td/@  
public TestMethod() =CD:.FG.  
{ ///xx/weblogic60b2_win.exe A;/Xt  
try{ ;iwD/=Y  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LN,$P  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J.CZR[XF#  
SiteFileFetch fileFetch = new SiteFileFetch(bean); zD#+[XI]K  
fileFetch.start(); XY$cx~  
} RP ScP  
catch(Exception e){e.printStackTrace ();} #/& q  
)VSGqYr#  
_zVbqRHlw  
} g*"J10hyP  
y$;zTH_6j  
j,gM+4V^  
public static void main(String[] args) 7+A-7ci  
{ _S%OX_UMn^  
new TestMethod(); \k$]GK-  
} .PA ?N{z  
} !'6J;Fb#  
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