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http断点续传简单实现(java)

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/* elP#s5l4  
**SiteFileFetch.java }iB>3|\  
*/ Z2k5qs7g  
package NetFox; ` B+Pl6l)F  
import java.io.*; Pj*"2 LBW#  
import java.net.*; .ldBl  
@#5?tk0  
(G{2ec:?  
public class SiteFileFetch extends Thread { 3HX-lg`0  
hXn@vK6  
S'AS,'EnY  
SiteInfoBean siteInfoBean = null; //文件信息Bean G0x!:[  
long[] nStartPos; //开始位置 '[[*(4 a3  
long[] nEndPos; //结束位置 7{ QjE  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 V%J_iY/BUb  
long nFileLength; //文件长度 -$y/*'  
boolean bFirst = true; //是否第一次取文件 ,aSK L1  
boolean bStop = false; //停止标志 sRGIHT#  
File tmpFile; //文件下载的临时信息 V"sm+0J  
DataOutputStream output; //输出到文件的输出流 QPsvc6ds  
k=5v J72U  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) t$U eks  
public SiteFileFetch(SiteInfoBean bean) throws IOException l`AA<Rj*O-  
{ Be0v&Q_NK  
siteInfoBean = bean; |DoD.?v  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); &-`a`  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); )/?s^D$,  
if(tmpFile.exists ()) Pill |4c<  
{ 6 Zv~c(   
bFirst = false; jX91=78d  
read_nPos(); M4}zRr([.5  
} +0n,>eDjg^  
else d7L|yeb"  
{ C;rK16cn  
nStartPos = new long[bean.getNSplitter()]; Kdd5ysTQ  
nEndPos = new long[bean.getNSplitter()]; #TY[\$BHs  
} 5%XEybc2  
]4-t*Em  
CLY>M`%?+p  
]=0$-ImQ@x  
} fmk(}  
-gLU>I7wV  
* n>YS  
public void run() |K$EULzz  
{ ]Y6y ]u  
//获得文件长度 i.>d#S  
//分割文件 17;qJ_T)  
//实例FileSplitterFetch Gv }~  
//启动FileSplitterFetch线程 e{IwFX  
//等待子线程返回 $PKUcT0N9  
try{ Y\7/`ty  
if(bFirst) uF\f>E)/N%  
{ l#%G~c8x  
nFileLength = getFileSize(); % KmhR2v  
if(nFileLength == -1) )u_[cEJHO  
{ *[wj )  
System.err.println("File Length is not known!"); L@LT*M  
} WzO[-csy  
else if(nFileLength == -2) V]A*' ke/  
{ ;"D I)hd z  
System.err.println("File is not access!"); &<S]=\  
} hvU\l`m  
else {}v<2bS  
{ }VXZM7@u  
for(int i=0;i<nStartPos.length;i++) /7XVr"R  
{ D,;6$Pvg^  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); G_n~1?  
} yM*< BV  
for(int i=0;i<nEndPos.length-1;i++) $iAd)2LT  
{ _^u^@.Q'i<  
nEndPos = nStartPos[i+1]; a'A'%+2  
} E,:E u<  
nEndPos[nEndPos.length-1] = nFileLength; /kK:{  
} \I`g[nT|  
} e't1.%w  
!mRDzr7  
3k?|-js  
//启动子线程 S.A|(?x  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ! V;glx[  
for(int i=0;i<nStartPos.length;i++) &IgH]?t  
{ cu$i8$?t   
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $79-)4;z4  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n!t][d/g+  
nStartPos,nEndPos,i); .< /.(7  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tR% &.,2  
fileSplitterFetch.start(); B< BS>(Nr>  
} 14;lB.$p  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wc- 8j2M  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XP!7@:  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Pi:=0,"XOp  
nEndPos = " + nFileLength); i5^U1K\M  
// fileSplitterFetch[nPos.length-1].start(); W8{zV_TBm  
|F^h >^ x  
%oEvp{I  
//等待子线程结束 x$\w^h\F  
//int count = 0; /0I=?+QSo  
//是否结束while循环 Di8;Tq  
boolean breakWhile = false; \mp5G&+/Q  
%G>V .d  
8NzXe 7  
while(!bStop) TZ+2S93c  
{ `h|>;u   
write_nPos(); >n^[-SWJCT  
Utility.sleep(500); sOLR*=F{  
breakWhile = true; &24z`ZS[w6  
@s/0 .7  
Kw ^tvRt'*  
for(int i=0;i<nStartPos.length;i++) [?Ub =sp  
{ i@ XFnt  
if(!fileSplitterFetch.bDownOver) CHRO9  
{ oc3}L^aD  
breakWhile = false; b5Pakz=jNM  
break; 9F"Q2^l'  
} `OmYz{*r  
} L=WB'*N  
if(breakWhile) 9K`uGu  
break; !~~j&+hK\  
gC qQ~lWZ  
M~&X?/8  
//count++; nzK"eNDN.  
//if(count>4) <<[hZ$.  
// siteStop(); 'U'#_mYG  
} *=ymK*  
r@m2foaO  
2r|!:^'?W  
System.err.println("文件下载结束!"); wk"zpI7L  
} "G`8>1tO_  
catch(Exception e){e.printStackTrace ();} Z w&_Wt  
} y3vm+tJc{  
^9C9[$Q  
{<3>^ o|"  
//获得文件长度 ;Jrk#7  
public long getFileSize() Yi+~}YP.E(  
{ kGX;x}q  
int nFileLength = -1; ]\t+zF>&Y  
try{ HGjGV]N5  
URL url = new URL(siteInfoBean.getSSiteURL()); : 'LG%E:b  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =wy3h0k^  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^."HD(  
IN%04~= H  
`e!hT@Xxa  
int responseCode=httpConnection.getResponseCode(); w+0Ch1$  
if(responseCode>=400) /o_h'l|PS  
{ )4P5i b  
processErrorCode(responseCode); Qe )#'$T  
return -2; //-2 represent access is error axW4 cS ?  
} ].eY]o}=  
)tV^)n[w  
BsX# ~  
String sHeader; \!tS|h  
Lx"a#rZ  
mTW@E#)n  
for(int i=1;;i++) `1[GY){?)  
{ %g>{m2o  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PNbs7f  
//Utility.log(in.readLine()); !F|iL  
sHeader=httpConnection.getHeaderFieldKey(i); k5@_8Rc  
if(sHeader!=null) hoQ?8}r:  
{ #`0iN+qh  
if(sHeader.equals("Content-Length")) -^JGa{9*  
{ |e@Bi#M[  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Um$a9S8b&  
break; UT9=S21  
} HGgw<Os-k  
} \O7?!i  
else Tcglt>tj"  
break; Ht'jm(  
} '\2lWR]ndd  
} Z)U#5|sf  
catch(IOException e){e.printStackTrace ();} ;')T}wuq  
catch(Exception e){e.printStackTrace ();} _ z!0ab  
'd"\h#  
X&<#3n  
Utility.log(nFileLength); -^ (NIl'  
L^`oJ9k!  
.F~EQ %  
return nFileLength; cg,_nG]i  
} }<wj~f([  
+(3PY  e\  
|7CH  
//保存下载信息(文件指针位置) "iof -b=ys  
private void write_nPos() 8bX\^&N  
{ \?} {wh8  
try{ A*h)p@3t<  
output = new DataOutputStream(new FileOutputStream(tmpFile)); [^gSWU  
output.writeInt(nStartPos.length); '7F`qL\/#(  
for(int i=0;i<nStartPos.length;i++) H\kqmPl&  
{ ^/Hj^4~_U  
// output.writeLong(nPos); k*4?fr  
output.writeLong(fileSplitterFetch.nStartPos); m,u? ^W  
output.writeLong(fileSplitterFetch.nEndPos); >oc7=F<8lS  
} R $cO`L*s  
output.close(); Pc]c8~  
} Ej1 [ry  
catch(IOException e){e.printStackTrace ();} VmTk4?V4  
catch(Exception e){e.printStackTrace ();} b)u9#%Q  
} d]e`t"Aj  
r)mm8MI!Z  
)N-+,Ms  
//读取保存的下载信息(文件指针位置) UY **3MK  
private void read_nPos() @ %z5]w  
{ l1o dkNf|  
try{ n20H{TA  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IBVP4&}x$  
int nCount = input.readInt(); WII_s|YSt%  
nStartPos = new long[nCount]; 0EXAdRR  
nEndPos = new long[nCount]; kmW!0hm;e  
for(int i=0;i<nStartPos.length;i++) lb1(1 |#  
{ \Mlj 7.u]  
nStartPos = input.readLong(); U gB  
nEndPos = input.readLong(); e7L;{+XI  
} LFSOHJj  
input.close(); su=.4JcK  
} xuelo0h,  
catch(IOException e){e.printStackTrace ();} "0L@cOyG  
catch(Exception e){e.printStackTrace ();} ?NI)3-l  
} %!rsu-W:Y  
,XP9NHE  
i=2+1 ;K  
private void processErrorCode(int nErrorCode) UsQv!Cwu^  
{ NUL~zb  
System.err.println("Error Code : " + nErrorCode); #G#gB   
} p,D/ Pb8  
yB. 6U56  
c2"eq2'BS  
//停止文件下载 kXX RMR  
public void siteStop() v%aD:%wlY@  
{ 5<w0*~Z d~  
bStop = true; qrX6FI  
for(int i=0;i<nStartPos.length;i++) o7 !@WOeZ3  
fileSplitterFetch.splitterStop(); '~ ]b;nA  
kd\yHI9A  
Mdwh-Cis/  
} !s)2H/KM8  
} _k+Bj.L  
//负责部分文件的抓取 *rEW@06^\  
**FileSplitterFetch.java iCx'`^HnP  
*/ g1J]z<&  
package NetFox; f\(Kou$  
db%`- UST  
P6=|C;[  
import java.io.*; # |UrHK;  
import java.net.*; ;U`HvIch  
5WZLB =  
103Ik6.o  
public class FileSplitterFetch extends Thread { _X.M,id  
&P {%C5?{  
8'cDK[L  
String sURL; //File URL 3YT _GW{  
long nStartPos; //File Snippet Start Position 'ZDa*9nkF  
long nEndPos; //File Snippet End Position <I|ryPU9{X  
int nThreadID; //Thread's ID jA]xpf6}  
boolean bDownOver = false; //Downing is over v5$zz w  
boolean bStop = false; //Stop identical -=qmYf  
FileAccessI fileAccessI = null; //File Access interface f CVSVn"o  
Yp ? 2<  
|R[m&uOib  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YT:5J%"  
{ cL WM]\Y  
this.sURL = sURL; 9Pb0Olh  
this.nStartPos = nStart; 0^[$0]Mt[  
this.nEndPos = nEnd; fg1 zT~  
nThreadID = id; =q"3a9 pb7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ahebr{u  
} X>wQYIi  
JqZ%*^O  
Y.C*|p#  
public void run() QnGJ4F  
{ }M~AkJL  
while(nStartPos < nEndPos && !bStop) ]jYl:41yI  
{ dvj`%?=  
,,iQG' *  
"M*\,IH  
try{ @LmUCP~  
URL url = new URL(sURL); E|fPI u  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $ `ho+  
httpConnection.setRequestProperty("User-Agent","NetFox"); <St`"H  
String sProperty = "bytes="+nStartPos+"-"; (HJ60Hj  
httpConnection.setRequestProperty("RANGE",sProperty); Yp;x  
Utility.log(sProperty); S n+Yi  
7vWB=r>5@  
~gAx  
InputStream input = httpConnection.getInputStream(); HYY|) Wo  
//logResponseHead(httpConnection); (C:rH  
;}PL/L$L6;  
N,1wfOE  
byte[] b = new byte[1024]; TUUBC%  
int nRead;  6$Dbeb  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #QB`'2)vw  
{ Ar$LA"vu4  
nStartPos += fileAccessI.write(b,0,nRead); }$UFc1He\J  
//if(nThreadID == 1) I'j? T.  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w7W-=\Hvh  
} #nd,cn  
_8`|KY  
8_ LDS  
Utility.log("Thread " + nThreadID + " is over!"); r#j*vO '  
bDownOver = true; &vn9l#\(  
//nPos = fileAccessI.write (b,0,nRead); RU'J!-w{  
} HvngjP{>  
catch(Exception e){e.printStackTrace ();} _1Eyqh`oh  
} ["7}u^z@<+  
} Cm&itG  
Tv KX8m"  
aG ,uF  
//打印回应的头信息 &V ;a:  
public void logResponseHead(HttpURLConnection con) .6hH}BM  
{ I F@M  
for(int i=1;;i++) Nf~<xK  
{ -Z@ p   
String header=con.getHeaderFieldKey(i); O| 2Q- @D  
if(header!=null) _Dv^~e1c  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ppYz~ {"r  
Utility.log(header+" : "+con.getHeaderField(header)); r3-3*_  
else i>~?XVU  
break; D'&L wU,o  
} :z:Blp>nK/  
} Mc6y'w  
 96BMJE'  
G1l(  
public void splitterStop() GB=q}@&8p  
{ e'`oisJU?q  
bStop = true; N 4:'X6u;  
} : ?V;  
?-f>zx8O  
Cr` 0C  
} Yc$|"to  
)0Lq>6j9  
2Ar<(v$  
/* zaZnL7ZJX  
**FileAccess.java ZUu^==a  
*//文件访问(定位,写) W< n`[  
package NetFox; 9NT;^K^ I  
import java.io.*; i_MI!o  
gr;M  
(pmo[2kg  
public class FileAccessI implements Serializable{ EDo (  
|h7v}Y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H07j&  
RandomAccessFile oSavedFile; |}`5< a!6U  
long nPos; (TE2t7ab|M  
VC.?]'OqD  
qEAF!iB]L  
public FileAccessI() throws IOException r>Ln*R,9D  
{ I?>#neHc6  
this("",0); <%z/6I Af|  
} B4}XK =)  
Y[!a82MTzn  
]Q3Gj@6  
public FileAccessI(String sName,long nPos) throws IOException 8VZ-`?p  
{ zCHr  
oSavedFile = new RandomAccessFile(sName,"rw"); x3Ud0[(  
this.nPos = nPos; xeI{i{8  
oSavedFile.seek(nPos); "YL-!P  
} :3B\,inJ  
$c}0L0  
}$-VI\96  
public synchronized int write(byte[] b,int nStart,int nLen) a%dx\&K  
{ pd#/;LT  
int n = -1; b5DrwX{Ff  
try{ L,6Y=?  
oSavedFile.write(b,nStart,nLen); v\Ljm,+  
n = nLen; |=LkV"_v  
} FT~^$)8=  
catch(IOException e) 4i,SiFKB  
{ Bu1z$#AC  
e.printStackTrace (); #lF<="y%X  
} c #kV+n<  
mV,R0olF  
^aXBt  
return n; "b 0cj  
} aJ8pJ{,P  
rg,63r  
vNC0M:p,  
} ]D%k)<YK  
N-gRfra+8L  
H#inr^Xa  
/* E: GJ$I  
**SiteInfoBean.java $J6.a!5IE  
*/ LzRiiP^q  
package NetFox; \#aVu^`eX  
?^~"x.<nr  
yUO|3ONT  
public class SiteInfoBean { { ZX C%(u  
PoJ$%_a}  
L2'd sOn  
private String sSiteURL; //Site's URL :2E1aVo4b  
private String sFilePath; //Saved File's Path j&A3s{S4A  
private String sFileName; //Saved File's Name opMUt,4  
private int nSplitter; //Count of Splited Downloading File KIo}Gd&  
ZRB 0OH  
Yys~p2  
public SiteInfoBean() PQ}%}S7:  
{//nSplitter的缺省值为5 |l xy< C4V  
//default value of nSplitter is 5 hZ<btN .y5  
this("","","",5); cA? x(  
} |L;psK  
xV#a(>-4  
Hc]1mM  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rf->mk{  
{ f_ztnRw  
sSiteURL= sURL; /y)"j#-eW  
sFilePath = sPath; |A0$XU{  
sFileName = sName; v9U(sEDq  
this.nSplitter = nSpiltter; 6;cY!  
Da [C'm=  
N@6OQ:,[F  
} Z=@)  
u!o]Co>  
NRisr  
public String getSSiteURL() X5Y `(/V  
{ e({fY.)SGo  
return sSiteURL; S2E HmE&  
} PuCDsojclh  
4|N\Q=,  
o^Ysp&#p  
public void setSSiteURL(String value) v Q"s  
{ `8;,&<U'`  
sSiteURL = value; hF"g 91P  
} QO{=Wi-  
JA(fam~{  
EWIc|b:  
public String getSFilePath() 3]<re{)J9O  
{ *frJ^ Ws{  
return sFilePath; S9R]Zl7{-  
} k0_$M{@Y  
qQOD  
_1<'"u#6w  
public void setSFilePath(String value) tRnW%F5  
{ {Y91vXTz7  
sFilePath = value; 6@q[tN7_^  
} oL'1Gm@X?  
.3<IOtD=  
Jh4&Qh|t  
public String getSFileName() 3;MjO*-  
{ ZuvPDW%  
return sFileName; V.ji _vX  
} ] 5v4^mk  
qmA2bw]  
oL Vtu5  
public void setSFileName(String value) qzA]2'~Q  
{ 0sDwTb"  
sFileName = value; BwJ^_:(p~  
} b/B`&CIA0"  
Y^2Qxo3"3  
u:$x6/t  
public int getNSplitter() j- YJ."  
{ a4( ?]ND~6  
return nSplitter; 6lmiMU&V  
} q^1aPz  
$tCcjBK\  
{^2W>^  
public void setNSplitter(int nCount) f{Fe+iPc  
{ 'B (eMnLg  
nSplitter = nCount; LuP?$~z  
} hiRR+`L%  
} cZr G:\A  
Vp $wHB&  
a-5HIY5  
/* "f|(@a  
**Utility.java pAil]f6  
*/ sQ}%7BMK  
package NetFox; <s/<b*T ^  
d)0LVa(  
(+UmUx=  
public class Utility { LR3`=Z9  
~#"7,rQp  
)ojx_3j8  
public Utility() N xb\[  
{ _t|G@D{   
+Cf0Y2*@hM  
YxEbg(Y  
} qA/#IUi)1  
mT6q}``vtG  
//线程睡眠 /e|[SITe  
public static void sleep(int nSecond) 8Y\OCwO  
{ HX3D*2v":  
try{ [Iw>|q<e  
Thread.sleep(nSecond); IAP/G5'Q  
} C[xJU6z  
catch(Exception e) 1t~FW-:  
{ Y  .  
e.printStackTrace (); dXiE.Si  
} 1xO!w+J#  
} )d}H>Qx=  
ut4r~~Ar  
//日志 v._Egk0  
public static void log(String sMsg) %9T~8L @.  
{ Dc.n-ipv$  
System.err.println(sMsg); M!Z*QY."P  
} hIVI\U,  
3cOY0Z#T  
jVad)2D  
public static void log(int sMsg) *%X6F~h(u  
{ v Zb|!#I  
System.err.println(sMsg); -c+>j  
} >-5td=:Z  
} .!yWF?T8  
1mHwYT+  
 ofMu3$Q  
/* ZD5I5  
**TestMethod.java uw Kh  
*/ VY/|WD~"CW  
package NetFox; j-J(C[[9  
48tcgFg[  
M*5,O   
public class TestMethod { uW}Hvj;0a*  
URYZV8=B~  
q.=^i z&m  
public TestMethod() e9CP802#2  
{ ///xx/weblogic60b2_win.exe +`;+RDKY*  
try{ 0A#*4ap  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N[qA2+e$Z  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _1>SG2h{fV  
SiteFileFetch fileFetch = new SiteFileFetch(bean); fav5e'[$  
fileFetch.start(); R=-+YBw7/  
} *8$>Whr  
catch(Exception e){e.printStackTrace ();} X"h%tsuw  
-7>^ rR V  
`"a? a5]k  
} 8P,l>HA  
WD15pq l  
iH-bo@  
public static void main(String[] args) 2E$^_YT C  
{ EXA^!/)  
new TestMethod(); Ci~f#{  
} tm(v~L%$>]  
} JY{X,?s  
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