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http断点续传简单实现(java)

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/* D._q'v<  
**SiteFileFetch.java 9O?.0L  
*/ Bb]pUb  
package NetFox; ):+n!P  
import java.io.*; d vkA-9  
import java.net.*; QT9(s\u  
WHvN6  
]$4k+)6  
public class SiteFileFetch extends Thread { %K;,qS'N_  
"xa<Q%hk  
j?+FS`a!  
SiteInfoBean siteInfoBean = null; //文件信息Bean 4bhm1Q  
long[] nStartPos; //开始位置 *r?g&Vw$m  
long[] nEndPos; //结束位置 4NQS'*%D  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 E4HG`_cWb  
long nFileLength; //文件长度 u\ytiGO*  
boolean bFirst = true; //是否第一次取文件 _|wgw^.LJ]  
boolean bStop = false; //停止标志 37a"<  
File tmpFile; //文件下载的临时信息 I^[R]Js  
DataOutputStream output; //输出到文件的输出流 /o.wCy,J<  
E[Tz%x=P  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) HpSgGhL'J&  
public SiteFileFetch(SiteInfoBean bean) throws IOException ]b.@i&M  
{ #|GP]`YT  
siteInfoBean = bean; |Ag~k? QC  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); <!Nj2>  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); rV"<1y:g  
if(tmpFile.exists ()) ,@/b7BVv  
{ `U#*O+S-^  
bFirst = false; PGP9-M  
read_nPos(); 2!-ZNd:(+  
} LP7t*}PK  
else C=h$8Q  
{ Dsm_T1X  
nStartPos = new long[bean.getNSplitter()]; :v* _Ay  
nEndPos = new long[bean.getNSplitter()]; %8yfF rk  
} vE>J@g2#  
+Ys<V  
?c+_}ja,  
f /&Dy'OV7  
} uwyzxj  
Ii,e=RG>  
S M@l4GH  
public void run() x5WFPY$wM  
{ I6M 7xn  
//获得文件长度 GW ?.b_6*  
//分割文件 *["9;_KD  
//实例FileSplitterFetch YnNB#x8|  
//启动FileSplitterFetch线程 { e<J}-/?  
//等待子线程返回 (%oZgvM  
try{ G>M# BuU  
if(bFirst) f:B+R  
{ .*r ?zDV  
nFileLength = getFileSize(); 7F>5<Gv:-  
if(nFileLength == -1) }C}~)qaZv+  
{ ,1Suq\ L  
System.err.println("File Length is not known!"); c;&m}ImLe.  
} P cnr  
else if(nFileLength == -2) /wljb b/s  
{ ?>1AT ==wI  
System.err.println("File is not access!"); go|/I&  
} &[3 xpi{v  
else Fs|fo-+H}k  
{ ES;7_.q  
for(int i=0;i<nStartPos.length;i++) "e69aAA,  
{ q+19EJ(  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); [~W"$sT  
} #@;RJJZg  
for(int i=0;i<nEndPos.length-1;i++) {<\nl#}5S  
{ V);{o>%.K  
nEndPos = nStartPos[i+1]; [0lCb"  
} 'D1 T"}  
nEndPos[nEndPos.length-1] = nFileLength; N~;=*)_VH  
} ua0`&,a3I  
} WQ\'z?P  
dFjB &#Tl  
Gk;==~  
//启动子线程 WLP A51R  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q i&!IG  
for(int i=0;i<nStartPos.length;i++) hvtg_w6K  
{ %DqF_4U9  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A@Z&ZBDg  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y5kqnibh@  
nStartPos,nEndPos,i); czi$&(N0w$  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %ErL L@e  
fileSplitterFetch.start(); L Bb&av  
} Cl7IP<.  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1tDd4r?Y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m>x.4aO1  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \;&j;"c,W  
nEndPos = " + nFileLength); :2^%^3+V  
// fileSplitterFetch[nPos.length-1].start(); KqP! ={>"  
SuB;Nb7r`  
c_~)#F%P  
//等待子线程结束 |qH-^b.F  
//int count = 0; Sqed*  
//是否结束while循环 Lp 5LRw  
boolean breakWhile = false; >to NGGU=~  
[<}:b>a  
x>A(016:C  
while(!bStop) /1zi(z   
{ \L}Soe'  
write_nPos(); f>s3Q\+  
Utility.sleep(500); !e?=I  
breakWhile = true; "A~\$  
awB1ryrOF  
89v9BWF  
for(int i=0;i<nStartPos.length;i++) DxdiXf[j  
{ j5Vyo>  
if(!fileSplitterFetch.bDownOver) :7K cD\fCj  
{ \zR@FOl`q  
breakWhile = false; q{ItTvL  
break; S;kI\;  
} &?"(al?  
} Zgkk%3'^'  
if(breakWhile) M/x49qO#  
break; ( MWh|kp  
eGHxiC  
^ b{0|:  
//count++; Jt\?,~,  
//if(count>4) &p8b4y_  
// siteStop(); -M2c8P:.b  
} <.HX_z3l  
m=jxTZK  
z4!TK ps  
System.err.println("文件下载结束!"); ?x7zYE,6  
} &W`."  
catch(Exception e){e.printStackTrace ();} gXZC%S  
} dT4?8:  
W=|sy-N{2  
*IG} /O.VT  
//获得文件长度 X!ZUR^  
public long getFileSize()  qa)X\0  
{ )cJ9YKKy  
int nFileLength = -1; z lco? Rt  
try{ =3$JeNK9  
URL url = new URL(siteInfoBean.getSSiteURL()); Qh<_/X?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w6zB uW  
httpConnection.setRequestProperty("User-Agent","NetFox"); wwE`YY  
|k1(|)%G  
V|e9G,z~A  
int responseCode=httpConnection.getResponseCode(); VI: !#  
if(responseCode>=400) es 8%JTi  
{ &<2~7?$!  
processErrorCode(responseCode); m X{_B!j^  
return -2; //-2 represent access is error ;9PJ K5>~  
} f]W$4f {  
%ZF47P%6  
[v ( \y  
String sHeader; Q'/v-bd?o  
/FJ )gQYA  
/Fy2ZYs,`8  
for(int i=1;;i++) b-ZC~#?|b  
{ ^&F8NEb=2>  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h)fJ2]JW8W  
//Utility.log(in.readLine()); fQ33J>  
sHeader=httpConnection.getHeaderFieldKey(i); `n7*6l<k~4  
if(sHeader!=null) Z`y%#B6x.  
{ Y> ElE-  
if(sHeader.equals("Content-Length")) 1vk& ;  
{ Opx"'HC@G  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OPOL-2<wiy  
break; bHZXMUewC  
} nb::,  
} ]awu7}C9Z  
else luXcr H+w  
break; 0`VA} c  
} mj:X'BVA  
} @px2/x  
catch(IOException e){e.printStackTrace ();} 1ml>  
catch(Exception e){e.printStackTrace ();} = i9|lU"Va  
(Qq;ySZ#  
7%DA0.g  
Utility.log(nFileLength); "I+71Ce  
}TE4)vXs  
7vO3+lT/Y;  
return nFileLength; i E p{  
} uvC ![j^~  
9jW/"  
M9so3L<N0  
//保存下载信息(文件指针位置) $fZVh%  
private void write_nPos() w6FtDl$  
{ P(AcDG6K  
try{ |rW,:&;  
output = new DataOutputStream(new FileOutputStream(tmpFile)); n1n->l*HGP  
output.writeInt(nStartPos.length); s\&qvL1D  
for(int i=0;i<nStartPos.length;i++) Ot,eAiaX  
{ ukNB#2 "  
// output.writeLong(nPos); .rpKSf.  
output.writeLong(fileSplitterFetch.nStartPos); is`O,Met  
output.writeLong(fileSplitterFetch.nEndPos); N~Zcrt_D  
} R8ZI}C1  
output.close(); En-BT0o  
} (Klvctoy  
catch(IOException e){e.printStackTrace ();} =, kH(rp2  
catch(Exception e){e.printStackTrace ();} >wx1M1  
} Q|T9 tc->  
tA;#yM;  
/A$mP)}tz  
//读取保存的下载信息(文件指针位置) yvN;|R  
private void read_nPos() gLp7<gx6  
{ (b!`klQ  
try{ <;)qyP  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Rf*cW&}%  
int nCount = input.readInt(); o}QtKf)W  
nStartPos = new long[nCount]; U4PnQ K,  
nEndPos = new long[nCount]; -hv<8bC~4  
for(int i=0;i<nStartPos.length;i++) sUl/9VKl  
{ A_nu:K-  
nStartPos = input.readLong(); Z'/sZ3Q}  
nEndPos = input.readLong(); RC{|:@]8  
} y*K]z  
input.close(); hf#[Vns  
} LYM(eK5V  
catch(IOException e){e.printStackTrace ();} &.D#OnRh9  
catch(Exception e){e.printStackTrace ();} %#gHa  
} aG&ay3[&  
s,~)5nL  
>2kjd  
private void processErrorCode(int nErrorCode) Owt|vceT  
{ zNg8Oq&  
System.err.println("Error Code : " + nErrorCode); 67,@*cK3?J  
} `]*BDSvE  
7l+>WB_]  
d4(!9O.\  
//停止文件下载 w+ MCOAB  
public void siteStop() !u0|{6U  
{ (zv)cw%  
bStop = true; znVao %b  
for(int i=0;i<nStartPos.length;i++) Fkq;Q  
fileSplitterFetch.splitterStop(); 0{0A,;b  
<Wz+f+HC  
)2lzPK t  
} ?|}%A9   
} .|d2s  
//负责部分文件的抓取 Fqr}zR)  
**FileSplitterFetch.java  v7Q=  
*/ 6xfG`7Az  
package NetFox; "V7 SB   
s01W_P.@R  
T~Z7kc'  
import java.io.*; P%%[_6<%M  
import java.net.*; 8AX+s\N  
Rq,ST:  
*U{E[<k{  
public class FileSplitterFetch extends Thread { Wu:@+~J.h  
R\VM6>SN'S  
j4C{yk  
String sURL; //File URL *d%U]Hby,  
long nStartPos; //File Snippet Start Position Xj;\ROBH-  
long nEndPos; //File Snippet End Position f*uD9l%/  
int nThreadID; //Thread's ID XwerQwO=  
boolean bDownOver = false; //Downing is over )U$]J*LI  
boolean bStop = false; //Stop identical Vy+UOV&v-  
FileAccessI fileAccessI = null; //File Access interface ~sk{O%OI  
uoX] #<1J  
+WGL`RP  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RMrrLT  
{ ,sn/FT^; q  
this.sURL = sURL; +[2X@J  
this.nStartPos = nStart; rEWPVT  
this.nEndPos = nEnd; F~qiNV  
nThreadID = id; VlLc[eVV  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !"dn!X  
} 9[L@*7A`m  
?M02|8-  
UN,y /V  
public void run() fxR}a,a  
{ $ 2/T]  
while(nStartPos < nEndPos && !bStop) BAQ;.N4  
{ 4t Z. T9d  
@qGg=)T  
vWM'}(  
try{ [+j39d.Q  
URL url = new URL(sURL); pbM"tr_A{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P0/B!8x  
httpConnection.setRequestProperty("User-Agent","NetFox"); *, Mg  
String sProperty = "bytes="+nStartPos+"-"; Xy;!Q`h(  
httpConnection.setRequestProperty("RANGE",sProperty); Z T5p  
Utility.log(sProperty); 6Eu&%`  
@Z50S 8  
Gkfc@[Z V  
InputStream input = httpConnection.getInputStream(); .W9/*cZV0  
//logResponseHead(httpConnection); cdH Ug#  
~w>Z !RuhT  
Ob|[/NN  
byte[] b = new byte[1024]; l:Y$A$W]>  
int nRead; [;]@PKW?w  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JN{xh0*  
{ _tGR:E  
nStartPos += fileAccessI.write(b,0,nRead); e1k\:]6  
//if(nThreadID == 1) cuw3}4m%  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OR\-%JX/5  
} 0lvX,78G;  
VB?mr13}G  
+]!`>  
Utility.log("Thread " + nThreadID + " is over!"); qZ39TTQ*p  
bDownOver = true; JMT?+/Qbu  
//nPos = fileAccessI.write (b,0,nRead); kOe~0xoT@u  
} 4]\t6,Cz8  
catch(Exception e){e.printStackTrace ();} 9hG+?   
} YBX7WZCR  
} i"rrM1/r  
!`VO#_TJ  
&M,"%w!  
//打印回应的头信息 BBg&ZIYEh  
public void logResponseHead(HttpURLConnection con) F[ Itq  
{ P'nbyF  
for(int i=1;;i++) 9t$%Tc#Z  
{ =&- hU|ur  
String header=con.getHeaderFieldKey(i); [SW@"C!  
if(header!=null) <IF\;,.c  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jZ'y_  
Utility.log(header+" : "+con.getHeaderField(header)); <N{pMz  
else iZ`1Dzxgk  
break; us.+nnd  
} N1V qK  
} Q&rf&8iH  
J)l]<##  
`P`n qn  
public void splitterStop() VH{SE7  
{ y %k`  
bStop = true; '(/ZJ88JP  
} 'z#{'`$a  
(VPT% l6  
Yg;g!~   
} q5$z:'zE  
mX8A XWIa  
vWJhSpC[  
/* ,u}n!quA  
**FileAccess.java 328(W  
*//文件访问(定位,写) ':7%@2Zo  
package NetFox; Q7y6</4f  
import java.io.*; -S=Zsr\  
HA{-XPAWZ  
;z9(  
public class FileAccessI implements Serializable{ NVnKgGlHgd  
lPS A  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (u]ajT  
RandomAccessFile oSavedFile; Bc4{$sc"O  
long nPos; J! 4l-.-  
;3n0 bKDY  
}*n(RnCn  
public FileAccessI() throws IOException lQ%]](a6  
{ 's{-1aW  
this("",0); h(;qnV'c  
} o8P 5C4y  
hfY Ieb#91  
? OBe!NDf  
public FileAccessI(String sName,long nPos) throws IOException ^i{B8]2,  
{ %*.;3;m  
oSavedFile = new RandomAccessFile(sName,"rw"); xDBEs*  
this.nPos = nPos; r\Wp\LfY&{  
oSavedFile.seek(nPos); j$*]'s&_hZ  
} -Uz xs5Zl  
1K'0ajl1A  
q{UP_6O F  
public synchronized int write(byte[] b,int nStart,int nLen) m_H$fioha,  
{ R]%ZqT{PS  
int n = -1; h2 Ifq!(:  
try{ oHmU|  
oSavedFile.write(b,nStart,nLen); 9p!V?cH#8  
n = nLen; n=RAE^[M  
} k=[!{I  
catch(IOException e) -[#Mx}%  
{ vd-`?/,||  
e.printStackTrace (); tg~&kaz  
} 66=6;77  
E{r_CR+8  
,_T,B'a:  
return n; "b*.>QuZ  
} $ 8w eh3p  
=JyYU*G4  
)2oWoZ vi9  
} |xH"Xvp:  
J`O4]XRY  
ewgcpV|spn  
/* @2 dp5  
**SiteInfoBean.java asR6,k  
*/ XJ]MPiXj  
package NetFox; >b-rAO\{}  
UD*#!H  
@Q x|!%  
public class SiteInfoBean { d@"eWvnlZ  
-!MDYj+U  
 ew4IAF  
private String sSiteURL; //Site's URL @hm %0L  
private String sFilePath; //Saved File's Path TE*$NxQ 2  
private String sFileName; //Saved File's Name 0+8ThZ?n  
private int nSplitter; //Count of Splited Downloading File ;,'!  
kTex>1W;  
*6Rl[eXS  
public SiteInfoBean() 'N5qX>Ob  
{//nSplitter的缺省值为5 1 X2oz  
//default value of nSplitter is 5 C[r YVa .  
this("","","",5); Y[T;j p(k  
} Ii*v(`2b  
)?pin|_x  
hzPx8sO  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5vY h~|  
{ "h7-nwm  
sSiteURL= sURL; hC]c =$=7  
sFilePath = sPath; jjvm<;lv  
sFileName = sName; "JVz v U]  
this.nSplitter = nSpiltter; D +)6#i Y  
S:vv*5  
{H $\,  
} dqUhp_f2qK  
F4 Ft~:a  
U3lr<(r*  
public String getSSiteURL() |i?AtOt@f  
{ p`1d'n[  
return sSiteURL; |gxU;"2`5~  
} Xk]5*C]6<  
X@9_ukdpu  
2k"a%#H8  
public void setSSiteURL(String value) /~7H<^}  
{ w}NgFrL  
sSiteURL = value; A i9*w?C  
} K;6K!6J:[  
tb/u@}")  
*&UVr  
public String getSFilePath() y%TR2CvT  
{ Jkm\{;  
return sFilePath;  2WE   
} I6y&6g  
yc]ni.Hz  
0 nWV1)Q0=  
public void setSFilePath(String value) rxa"ji!)  
{ cw"x0 RS  
sFilePath = value; _gC<%6#V`r  
} EemKYcE@Nr  
%/etoK  
|,dMF2ADc  
public String getSFileName() tt J,rM  
{ G:WMocyXI'  
return sFileName; ]N=C%#ki!  
} .2xypL8(  
tsfOPth$*  
YXI DqTA+  
public void setSFileName(String value) f[.hN  
{ 0A?w,A`"  
sFileName = value; a' #-%!]  
} Q(]-\L'  
&1Cq+YpI  
d'[aOH4}  
public int getNSplitter() 0E\R\KO$>  
{ D<++6HN&#  
return nSplitter; Mh+'f 93  
} >j`*-(`2fa  
i;)g0}x`  
 b 1[U 9  
public void setNSplitter(int nCount) 5)$U<^uy  
{ /=e[(5X|O  
nSplitter = nCount; sWavxh8A  
} ziH2<@  
} j~Gu;%tq  
bq(*r:`"  
[PX'Jer  
/* BLaX p0  
**Utility.java 'd U$QO  
*/ RTY$oUqlZ  
package NetFox; o=`9JKB~  
sM5 w~R>Y  
^G2vA8%  
public class Utility { 3l L:vD5(  
M0]l!x#7  
6J|f^W-fs  
public Utility() mu{%%b7|^  
{ X2@o"xU  
$}KYpSV  
@{CpC  
} :>3&"T.  
c(Ha"tBJ  
//线程睡眠 rM=Hd/ki5  
public static void sleep(int nSecond) {eZ j[*P  
{ #[KwR\b{:+  
try{ 4tuEC-oh  
Thread.sleep(nSecond); \~?s= LT  
} E?9_i :IX  
catch(Exception e) 1MahFeQ[  
{ 8OFrW.>[  
e.printStackTrace (); ZcWl{e4  
} Y}?@Pm drz  
} E,6E-9  
rk. UW  
//日志 \FKIEg+(2  
public static void log(String sMsg) 6op\g].P  
{ RDqC$Gu  
System.err.println(sMsg); /GeS(xzQ  
} ZDDwh&h  
,@!d%rL:4]  
S~TJF}[k^6  
public static void log(int sMsg) Z^~ 6pH\  
{ %@xYg{  
System.err.println(sMsg); KdR&OBm  
} <.v6w*+{/  
} n9J>yud|  
[KE4wz+s{  
BuvBSLC~  
/* u?J(l)gd  
**TestMethod.java CD tYj  
*/ Q-au)R,  
package NetFox; -[`W m7en  
5:PZ=jPR  
B}FF |0<  
public class TestMethod { n=>Gu9`  
xeH# )QJt  
l|fd,  
public TestMethod() A+}4 N%kh  
{ ///xx/weblogic60b2_win.exe =|#-Rm^YB  
try{ PA=BNKlH  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W1!eY,1}  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "Jwz.,Y\  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Grub1=6l  
fileFetch.start(); +]e4c;`ko}  
} 5 O6MI4:  
catch(Exception e){e.printStackTrace ();} FD-)nv2:  
b;O+QRa  
8&;dR  
} }dR *bG  
UetmO`qju  
zSH#j RDV  
public static void main(String[] args) kj#yG"3+  
{ ~k%\ LZ3s  
new TestMethod(); )~n}ieS  
} +O H."4Z  
} V& nN/CF  
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