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http断点续传简单实现(java)

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/* x7J8z\b"O  
**SiteFileFetch.java o5LyBUJ  
*/ Iz^h| n  
package NetFox; 6i'GM`>w  
import java.io.*; o1lhVM`15  
import java.net.*; ) rw!. )  
xs,,)jF(u  
CoZOKRoaH  
public class SiteFileFetch extends Thread { o]/*YaB2>  
>n$V1U&/  
VJbsM1y M  
SiteInfoBean siteInfoBean = null; //文件信息Bean Yw=7(}  
long[] nStartPos; //开始位置 c||EXFS}O  
long[] nEndPos; //结束位置 XX&4OV,^%D  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 nl<TM96  
long nFileLength; //文件长度 c(Ws3  
boolean bFirst = true; //是否第一次取文件 ?, B4  
boolean bStop = false; //停止标志 K Q^CiX  
File tmpFile; //文件下载的临时信息 F3nYMf  
DataOutputStream output; //输出到文件的输出流 j/ [V<  
SG \6qE~  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) *).u:>D4  
public SiteFileFetch(SiteInfoBean bean) throws IOException 2(I S*idq  
{ wtM1gYl^  
siteInfoBean = bean; 3qf?n5 "8  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 41uiW,  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); K}|zKTh:?  
if(tmpFile.exists ()) ES,T[  
{ w3Lr~_j  
bFirst = false; {,aX|*1Ku~  
read_nPos(); ~(*2 :9*0  
} \MqOHM.[  
else Jlp nR#@  
{ Sf*1Z~P|  
nStartPos = new long[bean.getNSplitter()]; V#X#rDfJZ  
nEndPos = new long[bean.getNSplitter()]; .n[;H;  
} ;n,xu0/  
mqj]=Fq*  
BSH2Kq  
*T6*Nxs0k  
} +~(SeTY  
KE[!{O^(a  
C&|K7Zp0v  
public void run()  jYUN:  
{ L:j3  
//获得文件长度 d! {]CZ"@  
//分割文件 4SVIdSA  
//实例FileSplitterFetch j%+>y;).  
//启动FileSplitterFetch线程 \)$:  
//等待子线程返回 =j~BAS*"  
try{ 5(5:5q.A/D  
if(bFirst) 2nf<RE>  
{ IJ]rVty  
nFileLength = getFileSize(); rMWJ  
if(nFileLength == -1) Gr-~&pm  
{ ,I6li7V  
System.err.println("File Length is not known!"); ^XX_ qC'1  
} :%_\!FvS  
else if(nFileLength == -2) Gsn$r(m{K  
{ p<[MU4  
System.err.println("File is not access!"); ) >te|@}o  
} j)ME%17  
else JR_%v=n~x  
{ !mZDukfjQ  
for(int i=0;i<nStartPos.length;i++) S86,m =  
{ `L LS|S]  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); \VpN:RI  
} }7*|s+F(f  
for(int i=0;i<nEndPos.length-1;i++) 'B:8tv  
{ (/7b8)g  
nEndPos = nStartPos[i+1]; o_8Wnx^  
} =kTHfdin&  
nEndPos[nEndPos.length-1] = nFileLength;  WD55(  
} YdDP;, DA  
}  VBUrtx:  
GQ(*k)'a  
\sz*M B  
//启动子线程 C(8VXtx_  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O^J=19Ri  
for(int i=0;i<nStartPos.length;i++) d.|*sZ&3p  
{ e%s1D  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AL!ppi  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), sZI"2[bk  
nStartPos,nEndPos,i); 'ZJb`  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EXMW,  
fileSplitterFetch.start(); Q6T"8K/  
} Fr~\ZL  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5S<Rz)1r  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #_eXybUV  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L{&>,ww  
nEndPos = " + nFileLength); zLgc j(;  
// fileSplitterFetch[nPos.length-1].start();  !2kM  
%QG3~b% h  
uK] -m  
//等待子线程结束 5dGfO:Dy_  
//int count = 0; <2d)4@B=  
//是否结束while循环 Pbd[gKX_  
boolean breakWhile = false; _@i-?Q  
)DmydyQ'  
}uNj#Uf  
while(!bStop) mqHcD8X  
{ wPEK5=\4Ob  
write_nPos(); mv>0j<C91  
Utility.sleep(500); mPU}]1*p  
breakWhile = true; @F] w]d  
SwsJ<Dq^z  
wFF,rUV  
for(int i=0;i<nStartPos.length;i++) 3?K+wg s  
{ 6cd!;Ca  
if(!fileSplitterFetch.bDownOver) A!,c@Kv 3  
{ zMRa <G7  
breakWhile = false; N5{v;~Cm}V  
break; A_l\ij$Y  
} w$IUm_~waa  
} (/At+MF3E  
if(breakWhile) ^vxx]Hji  
break; ,,H;2xYf  
F!3p )?  
:pM)I5MN[  
//count++; WH4rZ }Z`  
//if(count>4) @ <3E `j'p  
// siteStop(); DXG`%<ZMn  
} X~UL$S;  
pV(k6h  
Z^]jy>dj  
System.err.println("文件下载结束!"); 'z^'+}iyv  
} Ypl;jkHP  
catch(Exception e){e.printStackTrace ();} ^^&H:q  
} =@ acg0  
-<g[P_#  
e`co:HO`#  
//获得文件长度 e/cHH3 4  
public long getFileSize() `+T 2IPN  
{ HU'w[r 6a  
int nFileLength = -1; $@@ii+W}\  
try{ 9i U/[d  
URL url = new URL(siteInfoBean.getSSiteURL()); &',#j]I  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^, YTQ.O  
httpConnection.setRequestProperty("User-Agent","NetFox"); >-\^)z  
sBYDo{0 1  
JN:L%If  
int responseCode=httpConnection.getResponseCode(); ^\g.iuE  
if(responseCode>=400) yH=<KYk  
{  6/#+#T  
processErrorCode(responseCode); '%4fQ%ID}  
return -2; //-2 represent access is error W**[:n+  
} *+zFsu4l  
w,X)g{^T  
SHs [te[  
String sHeader; Lc?"4  
g%tUkM  
VQ,5&-9Y3  
for(int i=1;;i++) 1TX3/]:  
{ tH&eKM4G  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tvf5b8(Y-  
//Utility.log(in.readLine()); ?FNgJx*\S  
sHeader=httpConnection.getHeaderFieldKey(i); b1>]?.  
if(sHeader!=null) .rG~\Ws  
{ w_o+;B|I  
if(sHeader.equals("Content-Length")) bl&9O  
{ YhNrg?nS  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 45n.%*,  
break; )5n0P Zi  
} :!l.ze{F  
} $W=)-X\>  
else -<k)|]8  
break; %E/#h8oN{  
} +,,dsL  
} xOPQ~J|z  
catch(IOException e){e.printStackTrace ();} ;~DrsQb  
catch(Exception e){e.printStackTrace ();} y\j[\UZKO  
G~DHNO6  
~Er0$+q=Y;  
Utility.log(nFileLength); [T4{K &  
JBA{i45x  
xv Xci W  
return nFileLength; 8\9W:D@"x  
} b:'8_jL  
@67GVPcxl  
0 LXu!iix  
//保存下载信息(文件指针位置) (SQGl!Lai0  
private void write_nPos() *Gv:N6  
{ |EdEV*.ej  
try{ n:B){'S  
output = new DataOutputStream(new FileOutputStream(tmpFile)); A W6B[  
output.writeInt(nStartPos.length); g33Y$Xdk  
for(int i=0;i<nStartPos.length;i++) :R=7dH~r  
{ WV'u}-v^  
// output.writeLong(nPos); :CezkD&  
output.writeLong(fileSplitterFetch.nStartPos); Z2@e~&L  
output.writeLong(fileSplitterFetch.nEndPos); fd #QCs  
} xjF>AAM_Px  
output.close(); ~:k r;n2  
} )7!,_r  
catch(IOException e){e.printStackTrace ();} %QrOEs  
catch(Exception e){e.printStackTrace ();} ^!C  
} x^c,cV+*  
c%O97J.5b  
aCH;l~+U  
//读取保存的下载信息(文件指针位置) c$)>$&([  
private void read_nPos() !( +M  
{ ]mi\Y"RO  
try{ cAGM|%  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bf=\ED^  
int nCount = input.readInt(); hrD2 -S  
nStartPos = new long[nCount]; X jxa 2D  
nEndPos = new long[nCount]; !]}C!dXd  
for(int i=0;i<nStartPos.length;i++) j@#RfVx  
{ y{<js!au  
nStartPos = input.readLong(); 8@+<W%+th  
nEndPos = input.readLong(); N-b'O`C  
} fj['M6+wd  
input.close(); Cq7 uy  
} T%9t8?I  
catch(IOException e){e.printStackTrace ();} ]l h=ZC  
catch(Exception e){e.printStackTrace ();} B5+Q%)52  
} rN7JJHV  
)g?jHm-p\  
& ^1 b]f  
private void processErrorCode(int nErrorCode) ;qy;;usa  
{ k<j]b^jbz  
System.err.println("Error Code : " + nErrorCode); :-U& _%#w  
} @:B}QxC  
Y@q9   
oiR9NB&<  
//停止文件下载 (pM& eow}  
public void siteStop() ^fsC]9NS  
{ _g9j_ x:=  
bStop = true; -DJ ,<f*$  
for(int i=0;i<nStartPos.length;i++) z79oj\&[  
fileSplitterFetch.splitterStop(); As5l36  
OAFxf,b  
6< -Cpc  
} u\iKdL  
} oxeIh9 E  
//负责部分文件的抓取 gBWr)R  
**FileSplitterFetch.java RrH{Y0  
*/ |H,WFw1%}  
package NetFox; [>_zV.X  
9bRUN<  
/*e<r6  
import java.io.*; 6{udNv X  
import java.net.*; 5+Tx01 )  
8[t*VIXI  
hT_Q_1,  
public class FileSplitterFetch extends Thread { nO'C2)bBSG  
*' es(]W  
q9VBK(,X  
String sURL; //File URL :/6aBM?  
long nStartPos; //File Snippet Start Position v8'XchJ  
long nEndPos; //File Snippet End Position .}eM"Kv  
int nThreadID; //Thread's ID |{-?OOKj  
boolean bDownOver = false; //Downing is over ^x/D8 M  
boolean bStop = false; //Stop identical })kx#_o]'d  
FileAccessI fileAccessI = null; //File Access interface 1ljcbD)T;  
_-#o[>2[  
x $[_Hix  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;.xKVH/@  
{ {*g{9`   
this.sURL = sURL; {,6J*v"o  
this.nStartPos = nStart; P_mP ^L  
this.nEndPos = nEnd; `-cw[@uD  
nThreadID = id; x[)]u8^A  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9An \uH)mL  
} U6wy^!_X9  
UUbO\_&y  
t>LSP$  
public void run() ~#VDJ[Z  
{ 9vW]HOK  
while(nStartPos < nEndPos && !bStop) Y`$\o  
{ #u+qV!4  
Y=_*Ai  
@q># ]8  
try{ xQzW6H|  
URL url = new URL(sURL); lgK5E *^  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %|:j=/_  
httpConnection.setRequestProperty("User-Agent","NetFox"); ,CPAS}kS  
String sProperty = "bytes="+nStartPos+"-"; ez%:>r4  
httpConnection.setRequestProperty("RANGE",sProperty); 9M1DE  
Utility.log(sProperty); ~ Al3Dv9x  
}wBpBw2J  
 huyfo1(  
InputStream input = httpConnection.getInputStream(); :i {; 81V  
//logResponseHead(httpConnection); cD!E.2[  
c05-1  
u0)9IZxc  
byte[] b = new byte[1024]; vr?u=_%Z  
int nRead; Pk(%=P ,  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9&Y|,&W  
{ E;'{qp  
nStartPos += fileAccessI.write(b,0,nRead); *}Gys/\!S  
//if(nThreadID == 1) rK}sQ4z=  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kD1Nq~h2  
} lt]&o0>  
r}Gku0Hu_E  
5&_")k3$*  
Utility.log("Thread " + nThreadID + " is over!"); #cW :04  
bDownOver = true; xX{Zh;M&[  
//nPos = fileAccessI.write (b,0,nRead); ]mNsG0r6  
} uTJ z"c`F  
catch(Exception e){e.printStackTrace ();} eLgq )  
} XDyo=A]  
} gcO$T`  
& @_PY  
Ku uiU= (L  
//打印回应的头信息 ci:|x =  
public void logResponseHead(HttpURLConnection con) |)0Ta 9~  
{ (n2_HePE  
for(int i=1;;i++) 3,*A VcQA  
{ vd$>nJ"  
String header=con.getHeaderFieldKey(i);  4m=0e  
if(header!=null) 8r@GoG>  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); rFm?Bu  
Utility.log(header+" : "+con.getHeaderField(header)); c(b`eUOO  
else Bf+~&I#E  
break; 6CGk*s  
} 3fZoF`<a  
} ]:T:cO0_n  
y@2"[fo3~  
KyP@ hhj  
public void splitterStop() +;pw^QB  
{ pzQc UG  
bStop = true; E[zq<&P@  
} w~pe?j_F$  
oOubqx  
Z0'LD<  
} mF4OLG3L0  
ZZ :*c"b:  
0jxXUWO  
/* 55] MRv  
**FileAccess.java u WdKG({][  
*//文件访问(定位,写) cG@W o8+  
package NetFox; kJNg>SN*@#  
import java.io.*; ni )G  
tux`-F  
#SI]^T|  
public class FileAccessI implements Serializable{ E&L ml?@  
t.O~RE  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7 TM-uA$  
RandomAccessFile oSavedFile; k$#1T +(G  
long nPos; [ z/G  
Eg2jexl  
)S`Yl;oL  
public FileAccessI() throws IOException Hv:~)h$  
{ H0t#J  
this("",0); -=UvOzw  
} K9VP@[zbJ  
UMFM.GI  
a~JZc<ze  
public FileAccessI(String sName,long nPos) throws IOException v/$<#2|  
{ yOXEP  
oSavedFile = new RandomAccessFile(sName,"rw"); V,[[# a)y  
this.nPos = nPos; i*&b@.7N  
oSavedFile.seek(nPos); g_>E5z.  
} n? =O@yq  
cf"!U+x  
,Tx38  
public synchronized int write(byte[] b,int nStart,int nLen) )u]=^  
{ _ogN   
int n = -1; m@L>6;*  
try{ If'N0^'W  
oSavedFile.write(b,nStart,nLen); 1E4`&?  
n = nLen; pV 8U`T  
} S?D]P'<  
catch(IOException e) z 3Z8vq  
{ E0!0 uSg&  
e.printStackTrace (); L7xiq{t`Y  
} 9j-;-`$S  
M9~'dS'XI  
f= }!c*l"  
return n; **1=|aa:  
} A5%Now;.cf  
6-5{7E}/b  
&H}Xk!q5b^  
} W&I:z-VH  
GGZ9DC\{  
.]<gm9l  
/* XC}2GHO<  
**SiteInfoBean.java 30sA\TZ  
*/ AxO.adQE%  
package NetFox; qzZ;{>_f  
oGbh *  
"dYT>w  
public class SiteInfoBean { dg+"G|nr  
X%;4G^%ZI  
dEX67rUj;  
private String sSiteURL; //Site's URL 5dX0C  
private String sFilePath; //Saved File's Path c0X1})q$  
private String sFileName; //Saved File's Name p-!/p#  
private int nSplitter; //Count of Splited Downloading File )lUocm  
q8R,#\T*  
'fzJw  
public SiteInfoBean() zpNt[F?~1  
{//nSplitter的缺省值为5 ]'>jw#|h  
//default value of nSplitter is 5 2<AQ{ c  
this("","","",5); ew c:-2Y^  
} oJE<}~_k  
N>sHT =_  
!# xi^I  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ye}86{l  
{ J~ *>pp#U  
sSiteURL= sURL; "/taatcH  
sFilePath = sPath; B~O<?@]d  
sFileName = sName; *N6sxFs  
this.nSplitter = nSpiltter; P.^*K:5@  
=dWq B&  
Vy=+G~  
} 7MKZ*f@x;  
-y$<fu9 e  
lx ~C{tl2  
public String getSSiteURL() ys7 Tq+  
{ y^ st T^  
return sSiteURL; &*Kk> 4  
} j~9![s!  
V9>$M=  
VjeF3pmBa  
public void setSSiteURL(String value) 3?!c<^"e  
{ ]&='E.f  
sSiteURL = value; e_S,N0  
} (8NE'd8  
<Y;w I#C  
I-Hg6WtB  
public String getSFilePath() ;1r|Bx<5  
{ }`76yH^c  
return sFilePath; Wk }}f|O0  
} $g,v]MW  
ZlcEeG  
dtV7YPz4+  
public void setSFilePath(String value) oGt2n:  
{ ZF<$6"4N  
sFilePath = value; tq*6]q8c>  
} }Cb-7/  
@FRas00)|  
I(/*pa?m{  
public String getSFileName() ? Z2`f6;W4  
{ j5~~%  
return sFileName; 8\?H`NN  
} $KoGh_h   
<?Z]h]C^o  
e Zg>]<L  
public void setSFileName(String value) |h.@Xy  
{ w,<n5dMv  
sFileName = value; 7eFFKl  
} ^=gN >xP  
_+Pz~_+kS  
'PTQ S,E  
public int getNSplitter() 2frwU~y  
{ ,"?8  
return nSplitter; Jgq#m~M6  
} 1T4#+kW&  
b |ijkys  
rWN%j)#+  
public void setNSplitter(int nCount) Vw&# Lo  
{ )3 '8T>^<K  
nSplitter = nCount; 1>bNw-kz7  
} +h1X-K:I  
} yy`XtJBWWs  
n<A<Xj08T9  
>5 2%^ ?  
/* xo!2 GPD.  
**Utility.java Y7')~C`up^  
*/ `"#hhKG  
package NetFox; F&7^M0x\ O  
!2.eJ)G  
-^< t%{d  
public class Utility { VMu?mqEa  
*}>)E]O@  
TALiH'w6|e  
public Utility() M>{*PHze0  
{ @oD2_D2  
NjO_Y t  
zS`KJVm  
} S>s+ nqcP  
qv<^%7gq  
//线程睡眠 rG%8ugap  
public static void sleep(int nSecond) ZT<VDcP{  
{ ~sNBklK  
try{ sH%Ts@Pl  
Thread.sleep(nSecond); wZ_"@j<  
} }V 4u`=  
catch(Exception e) 5>VX]nE3!  
{ Z4sS;k]}  
e.printStackTrace (); MIqH%W.r u  
} okO\A^F  
} ]\/"-Y#4Q  
3sl6$NKo  
//日志 C4 -y%W"P  
public static void log(String sMsg) `yC[Fn"E^  
{ HNLr} Yj  
System.err.println(sMsg); ~1nKL0C6u  
} FyNm1QNy^  
D&OskM60  
({cWb:+r  
public static void log(int sMsg) D"IxQ2}k  
{ 5+q dn|9%T  
System.err.println(sMsg); TQQh:y  
} _SMi`ie#  
} ^-"tK:{  
r,:acK  
ONF x -U]  
/*  *qFl&*h}  
**TestMethod.java #S[Y}-]T  
*/ UQbk%K2  
package NetFox; x4v&%d=M  
lWUQkS  
eWr6@  
public class TestMethod { p!\ GJ a",  
#JN4K>_4  
i\x@s>@x}  
public TestMethod() xWM?E1@  
{ ///xx/weblogic60b2_win.exe n"@){:{4?  
try{ h+j*vX/!  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f6{.Uq%SGp  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \$gA2r  
SiteFileFetch fileFetch = new SiteFileFetch(bean); wZ=@0al  
fileFetch.start(); #oN}DP  
} g@Rs.Zq  
catch(Exception e){e.printStackTrace ();} }[(v(1j='~  
_`,ZI{.J^  
/L./-92NH4  
} u~~ ~@p  
o[q|dhrANh  
8fK/0u^`d  
public static void main(String[] args) Qkc 9X0J!  
{ Q /t_% vb  
new TestMethod(); VH vL:z  
} [p]UM;+  
} Q`Rn,kCVy  
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