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http断点续传简单实现(java)

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/* P{ %Urv{U  
**SiteFileFetch.java F/LMk8RgR  
*/ Q;z!]hjBM  
package NetFox; RS&BS;  
import java.io.*; Vh=U/{Rp1  
import java.net.*; Ylu\]pr9|C  
8BZ&-j{  
<2<2[F5Q%  
public class SiteFileFetch extends Thread { T+RC#&>  
!fe_w5S^  
@^ &p$:  
SiteInfoBean siteInfoBean = null; //文件信息Bean aY .cx1"  
long[] nStartPos; //开始位置 H0])>1sWB  
long[] nEndPos; //结束位置 P'}B5 I~  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 p{ZyC  
long nFileLength; //文件长度 ':tdb$h  
boolean bFirst = true; //是否第一次取文件 K8 [Um!(  
boolean bStop = false; //停止标志 h0dZr-c  
File tmpFile; //文件下载的临时信息 -(lP8Y~gFY  
DataOutputStream output; //输出到文件的输出流 kmu`sk"  
0!0o[3*  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) o+XQMg  
public SiteFileFetch(SiteInfoBean bean) throws IOException v{"yrC  
{ 0,@^<G8?  
siteInfoBean = bean; Svo\+S  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); u&TXN;I,p  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); t54?<-  
if(tmpFile.exists ()) 2,g4yXws5  
{ [.Fq l+  
bFirst = false; [7 r^fD A  
read_nPos(); tq'ri-c&b  
} /uR/,R++  
else k#\j\t-  
{ Eld[z{n"  
nStartPos = new long[bean.getNSplitter()]; \Z42EnJ  
nEndPos = new long[bean.getNSplitter()]; `s UY$Q  
} HIE8@Rv/3  
a(?)r[=  
9MI9$s2y  
Z'!ORn#M  
} {{M/=WqC  
E6O!e<ze^  
O8" t.W  
public void run() o%;ly  
{ ~a_X 7  
//获得文件长度 n=$ne2/  
//分割文件 .<fdX()e,  
//实例FileSplitterFetch Q}<QE:-&E  
//启动FileSplitterFetch线程 xw_)~Y%\  
//等待子线程返回 @Y.r ,q  
try{ FAM:; F30  
if(bFirst) o^"OKHU,S0  
{ GRofOJ  
nFileLength = getFileSize(); kF,ME5%  
if(nFileLength == -1) T=sAy/1oR  
{  |xg#Q`O  
System.err.println("File Length is not known!"); {5c?_U  
}  !=*8*?@  
else if(nFileLength == -2) C$C>RYE?.  
{ + %K~  
System.err.println("File is not access!"); vV 9vB3K5?  
} EH M59s|B  
else QZ;DZMP  
{ (^g XO  
for(int i=0;i<nStartPos.length;i++) P*|=Z>%[0  
{ w >2G@  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); a.?U $F  
} ~Sm6{L  
for(int i=0;i<nEndPos.length-1;i++) ]' Ho)Q  
{ OUGkam0UK  
nEndPos = nStartPos[i+1]; ;]>)6  
} ]W2#8:i  
nEndPos[nEndPos.length-1] = nFileLength; ,tyPZR_  
} @^ -Y&N!b=  
} (/]#G8  
CP%^)LX *  
U  yV5A  
//启动子线程 $>yfu=]?  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; % C2Vga#  
for(int i=0;i<nStartPos.length;i++) NR k~  
{ `]6<j<' ,  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .{`C>/"}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5%fWX'mS  
nStartPos,nEndPos,i); _JNYvng m  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r`EjD}2d  
fileSplitterFetch.start(); >s"/uo  
} fvi0gE@bd  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6\K\d_x  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y[}A4`  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", * O?Yp%5NH  
nEndPos = " + nFileLength); Q#qfuwz  
// fileSplitterFetch[nPos.length-1].start(); u'_}4qhCC;  
}Kp<w,  
GQA\JYw|oY  
//等待子线程结束 rrj.]^E_~  
//int count = 0; m}RZ )c  
//是否结束while循环 Z~-N'Lt{  
boolean breakWhile = false; Y(kf<Wo  
> .K%W *t  
?f q!BV  
while(!bStop) ]Z6? m  
{ Zxqlhq/)  
write_nPos(); Dr%wab"yy  
Utility.sleep(500); %3#C0%{x  
breakWhile = true; "Z,T%]  
l,l6j";ohd  
6XU p$Pd(  
for(int i=0;i<nStartPos.length;i++) BU??}{  
{ Gs3V]qbEP  
if(!fileSplitterFetch.bDownOver) 6G"UXNa,  
{ e:'56?|  
breakWhile = false; qT5"r488  
break; \ ya@9OA  
} |#Lz0<c;  
} p?cc Bq  
if(breakWhile) g9VY{[ V  
break; g\.$4N  
,3f>-mP  
GCO: !,1  
//count++; `<>QKpAn  
//if(count>4) kI@<H<  
// siteStop(); IHd W!q  
} "P(obk  
$rr@3H+  
m26YAcip}  
System.err.println("文件下载结束!"); ?(d1;/0v>  
} N AY3.e  
catch(Exception e){e.printStackTrace ();} u?dPCgs;h  
} U 887@-!3  
3Xd:LDZ{  
3Z*o5@RI  
//获得文件长度 {CBb^BP  
public long getFileSize() =dKjTBR S'  
{ { ,c*OR  
int nFileLength = -1; kVKAG\F  
try{ _]4 p51r0  
URL url = new URL(siteInfoBean.getSSiteURL()); *DfOm`m  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `m<O!I"A  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3Zd,"/RH  
zN[& iKf  
,z/aT6M?H  
int responseCode=httpConnection.getResponseCode(); E/%"%&`8j  
if(responseCode>=400) w@cW`PlF  
{ C]5 kQ1Og  
processErrorCode(responseCode); kV?fie<\)  
return -2; //-2 represent access is error Bz-jy.  
} v=lW5%r,'  
!1=OaOT  
!f52JQyh  
String sHeader; 2 Kjd!~Z$  
;2 &"  
breF,d$  
for(int i=1;;i++) LAf#Rco4  
{ O=}Rp 1  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1a{r1([)  
//Utility.log(in.readLine()); B^P&+,\[}  
sHeader=httpConnection.getHeaderFieldKey(i); &*+$38XE^  
if(sHeader!=null) f ?k0(rl  
{ h L [eA  
if(sHeader.equals("Content-Length")) -2J37   
{ 0g|5s  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vZTXvdF  
break; ^-k"gLg  
} P o@;PR=  
} =r ^_D=  
else ~Y CH5,  
break; o68i0aFW  
} T pF [-fO  
} DWKQ>X6  
catch(IOException e){e.printStackTrace ();} *1`X}  
catch(Exception e){e.printStackTrace ();} QE[<Y3M  
.aY $-Y<  
!KK`+ 9/  
Utility.log(nFileLength); Y 2ANt w@  
I)FFh%m<}a  
/^nIOAeE  
return nFileLength; OR~ui[w  
} #Iz)Mu  
J}xM+l7uY  
{E Ay~lo  
//保存下载信息(文件指针位置) H2R3I<j  
private void write_nPos() \'j(@b,  
{ S5TVfV5LI  
try{ ? F #&F  
output = new DataOutputStream(new FileOutputStream(tmpFile)); <YFDS;b|  
output.writeInt(nStartPos.length); U0j>u*yE  
for(int i=0;i<nStartPos.length;i++) qD>^aEd@4  
{ _`\!+qGq  
// output.writeLong(nPos); YWH>tt 9  
output.writeLong(fileSplitterFetch.nStartPos); ;NRh0)%|o  
output.writeLong(fileSplitterFetch.nEndPos); [C6ba{9 B  
} n Ab~  
output.close(); ?}s;,_GH  
} MBA?, |9Q#  
catch(IOException e){e.printStackTrace ();} 5>f"  
catch(Exception e){e.printStackTrace ();} [%dsq`b#  
} tjXg  
ktTP~7UVi  
aHW34e@ebL  
//读取保存的下载信息(文件指针位置) \~,\|  
private void read_nPos() *%KIq/V  
{ \Yr*x7!  
try{ d%'#-w'  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B0Wf$ s^7t  
int nCount = input.readInt(); v~L\[&|_  
nStartPos = new long[nCount]; FJ~d&L\l  
nEndPos = new long[nCount]; /&#y-D_  
for(int i=0;i<nStartPos.length;i++) I{(!h90  
{ lgU!D |v  
nStartPos = input.readLong(); cHFW"g78  
nEndPos = input.readLong(); ) >FAtE   
} "PI;/(kR  
input.close(); o( zez  
} *FC8=U2\X  
catch(IOException e){e.printStackTrace ();} C 6 \  
catch(Exception e){e.printStackTrace ();} jerU[3  
} Y%"$v0D  
bOr11?  
a`w=0]1&*  
private void processErrorCode(int nErrorCode) 6J,h}S  
{ a pa&'%7  
System.err.println("Error Code : " + nErrorCode); :Pdh##k  
} I8J>>H'#A  
H;nzo3x  
Zwc&4:5%  
//停止文件下载 `Uz.9_6  
public void siteStop() ~3:hed7:  
{ YTefEG]|q  
bStop = true; N+c|0  
for(int i=0;i<nStartPos.length;i++) La1:WYt  
fileSplitterFetch.splitterStop(); -6- sI  
'69)m~B0a  
W$hCI)m(  
} *P*~CHx>  
} :[n~(~7?  
//负责部分文件的抓取 Pt5wm\  
**FileSplitterFetch.java x/<]/D  
*/ /r~2KZE  
package NetFox; <pb  
_D4qnb@  
pE<a:2J  
import java.io.*; .2@T|WD!Ah  
import java.net.*; 49*f=gpGj2  
JE9v+a{7  
ZNw|5u^N  
public class FileSplitterFetch extends Thread { )m7%cyfC  
x!GDS>  
g3kbsi7_:  
String sURL; //File URL Gpxp8[ {  
long nStartPos; //File Snippet Start Position Q"FN"uQ}x  
long nEndPos; //File Snippet End Position ivo><"Y(r  
int nThreadID; //Thread's ID M 8WjqTq  
boolean bDownOver = false; //Downing is over RG45S0Ygj  
boolean bStop = false; //Stop identical lF(v<drkB  
FileAccessI fileAccessI = null; //File Access interface }XBF#BN  
Qt4mg?X/  
qWr=Oiu  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _)5E=  
{ 45.ks.  
this.sURL = sURL; /K li C\  
this.nStartPos = nStart; O oA!N-Q  
this.nEndPos = nEnd; t!rrYBSCr  
nThreadID = id; -r cEG!  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E6~VHQa2?  
} }~@/r5Zl  
SzpUCr"  
&{8:XJe*,%  
public void run() a%`Yz"<lQ  
{ ^x O](,H  
while(nStartPos < nEndPos && !bStop) Y[7prjd  
{ H[KX xNYZ_  
tP|/Q 5s  
Jp"29 )w  
try{ Z]b;%:>=  
URL url = new URL(sURL); .c]>*/(+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )Q`Ycz-  
httpConnection.setRequestProperty("User-Agent","NetFox"); =a,qRO  
String sProperty = "bytes="+nStartPos+"-"; x]wi&  
httpConnection.setRequestProperty("RANGE",sProperty); `e'wW V  
Utility.log(sProperty); FA,n>  
H1U$ApD  
bQ3<>e\%B  
InputStream input = httpConnection.getInputStream(); c+3(|k-M  
//logResponseHead(httpConnection); 87!jn'A  
dnD@BQ  
>A{Dpsi\  
byte[] b = new byte[1024];  Q(w;  
int nRead; pl r@  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Gz{%Z$A~o  
{ kB@gy}  
nStartPos += fileAccessI.write(b,0,nRead); _0Ea 3K  
//if(nThreadID == 1) O)&W0` VY  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AAa7)^R  
} vcQl0+&  
VCc=dME  
^9,^ BHlC0  
Utility.log("Thread " + nThreadID + " is over!"); =A,B'n\R  
bDownOver = true; `G!HGzVx;j  
//nPos = fileAccessI.write (b,0,nRead); 4$VDJ  
} 5 OWyxO3{  
catch(Exception e){e.printStackTrace ();} ++b[>};  
} k vZw4Pk  
} >U* p[FGW  
5;KJ0N*-  
-51LF=(!L  
//打印回应的头信息 5T.U=_ag  
public void logResponseHead(HttpURLConnection con) $>#0RzU  
{ h'em?fN(  
for(int i=1;;i++) 'v<v6vs  
{ tco G;ir  
String header=con.getHeaderFieldKey(i); A^).i_&#  
if(header!=null) fmK~?  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^dLu#,;  
Utility.log(header+" : "+con.getHeaderField(header)); }h Wv  p  
else &u&WP  
break; 4#>Z.sf  
} sTP\}  
} ^=^\=9" b  
&=)O:Jfa  
q n-f&R  
public void splitterStop() e bp t/q[  
{ oQ -m  
bStop = true; "[7-1}l  
} mmJnE  
O'(Us!aq  
( gg )?  
} AJB NM  
sm'_0EUg  
j=T8 b  
/* bDl#806PL  
**FileAccess.java !0lk}Uzkh  
*//文件访问(定位,写) N4,oO H~  
package NetFox; F<{,W-my `  
import java.io.*; mOj; 0 R  
tgG 8pL  
m2^vH+wD  
public class FileAccessI implements Serializable{ cdkEK  
 &ox  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +pG+ xI  
RandomAccessFile oSavedFile; $=diG  
long nPos; hO[_ _j8  
|oU I2<"  
kiJ=C2'&  
public FileAccessI() throws IOException &!4E3&+2m  
{ @.E9 ml  
this("",0); rM.Pc?Z  
} _fZec+oM  
h(yFr/  
hK)'dG*  
public FileAccessI(String sName,long nPos) throws IOException 3}s]F/e  
{ D+:s{IcL<  
oSavedFile = new RandomAccessFile(sName,"rw"); nuWQ3w p[e  
this.nPos = nPos; VK*_p EV,}  
oSavedFile.seek(nPos); RK-bsf  
} dQSO8Jf  
Pa0W|q#?X  
0IqGy}+VU  
public synchronized int write(byte[] b,int nStart,int nLen) d6*84'|!  
{ >6yQuB  
int n = -1; ^G`6Zg;  
try{ l4i 51S"  
oSavedFile.write(b,nStart,nLen); GdUsv  
n = nLen; <QvVPE}z   
} RuYIG?J=/  
catch(IOException e) 67&IaDts  
{ I)1ih  
e.printStackTrace ();  Mj1f;$  
} :(ql=+vDb4  
D$4GNeB+#  
'z,kxra|n  
return n; \5&Mg81  
} R98YGW_ dT  
^@8XJ[C,_  
'kj q C  
} nG3SDL#(k  
n\D/WLvM  
`XE>Td>Bs  
/* \Y"S4<"R  
**SiteInfoBean.java 0 cKsGDm  
*/ 2;T?ry7  
package NetFox; WqefH{PB  
+o4o!;E)  
Wjq9f;  
public class SiteInfoBean { ]Xa]a}[uE  
LE{@J0r#n  
Sak^J.~G[  
private String sSiteURL; //Site's URL |MKR&%Na  
private String sFilePath; //Saved File's Path _Jg#T~  
private String sFileName; //Saved File's Name {sB-"NR`K  
private int nSplitter; //Count of Splited Downloading File FJH>P\+  
\EU3i;BNT%  
][l5S*CC_  
public SiteInfoBean() GC# [&>L  
{//nSplitter的缺省值为5 J?TCP%  
//default value of nSplitter is 5 X=-=z5  
this("","","",5); 2~/`L=L  
} XdDQ$'*X  
SujEF` "  
VtzZ1/J E  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &TRKd)wd  
{ pD[&,gV$  
sSiteURL= sURL; ~SBW`=aP}  
sFilePath = sPath; 9;XbyA]  
sFileName = sName; MVzj7~+  
this.nSplitter = nSpiltter; p_BG#dRM  
^PFiO 12  
w uY-f4  
} :_i1gY)  
5P #._Em  
u q 9mq"  
public String getSSiteURL() !QAndg{;D  
{  !{V`N|0  
return sSiteURL; yx`@f8Kr  
} ='D%c^;O8'  
bE% Hm!  
'X+aYF }Ye  
public void setSSiteURL(String value) H#GR*4x  
{ =>PX~/o  
sSiteURL = value; W (TTsnnx  
} .(Ux1.0C  
>.P* lT  
qU6!vgM&  
public String getSFilePath() gmu.8  
{ b/*QV0(  
return sFilePath; $I-iq @  
} 3F;0a ;[  
m`zd0IRTP  
w7~]c,$y.  
public void setSFilePath(String value) 1f^oW[w&  
{ ,[p?u']yZz  
sFilePath = value; BeRs;^r+  
} i: -IZL\  
7ojh=imY  
=3hJti9[  
public String getSFileName() M.5F|7  
{ sCy.i/y  
return sFileName; YRZw|H{>t  
} =>Ae]mi 7  
Kc r)W  
h\#4[/  
public void setSFileName(String value) C`Vuw|Xl  
{ 1G`5FU  
sFileName = value; o+OX^F0  
} _d~GY,WTdO  
|af<2(d  
;QuxTmWp^  
public int getNSplitter() 6k,@+ @]t.  
{ 0|va}m`<3G  
return nSplitter; V^qBbk%l>D  
} :/? Op  
J.2BBy  
Yy[=E\z  
public void setNSplitter(int nCount) ^+~$eg&js  
{ uq:'`o-1  
nSplitter = nCount; ]lJ#|zd8o  
} >oy%qLHe~t  
} )rA\+XT7  
=#TQXm']Gi  
Jnt r"a-4  
/* tMf5TiWu@  
**Utility.java K'e!BZm6Q  
*/ "[A&S!  
package NetFox; [uie]*^  
b N>Ar  
/mE:2K]C  
public class Utility { c?xeBC1-  
vA*NJ%&`  
ZQz;EV!  
public Utility() {XhpxJ__  
{ )}w-;HX  
.*FlB>1jy  
/%?bO-  
} >)+U^V  
uTbMp~cYB  
//线程睡眠 (o6 u ^#6  
public static void sleep(int nSecond) W#b++}S  
{ mMhe,8E&  
try{ _;(Q MeR  
Thread.sleep(nSecond); 3joMtRB>;  
} \hzx?  
catch(Exception e) 3_VWtGQ  
{ 8v;T_VN  
e.printStackTrace (); n!b*GXb\  
} $[=`*m  
} ?K}KSJ6_  
JLyFk V/  
//日志 84Hm PPt  
public static void log(String sMsg) WFeaX7\b  
{ 5U<o%+^El  
System.err.println(sMsg); A]V<K[9:b  
} ~ C_2D?  
g=v[@{9Pw  
E\}Q9, Z$  
public static void log(int sMsg) kr1^`>O5  
{ d7c m?+  
System.err.println(sMsg); XnvaT(k7Y  
} ;rF:$37^  
} gY=+G6;=<  
6d 8n1_  
N) z] F9Kg  
/*  93 `  
**TestMethod.java T?5F0WKi  
*/ `+r5I5  
package NetFox; IZ4jFgpR  
8J9o$Se  
{24Pv#ZG#^  
public class TestMethod { 'Uo:b<  
~u-`L+G"6  
h"nv[0!)  
public TestMethod() 0$nJd_gW_  
{ ///xx/weblogic60b2_win.exe U`'w{~"D%  
try{ CV7.hF<  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); z!j`Qoh?V9  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m7mC 7x  
SiteFileFetch fileFetch = new SiteFileFetch(bean); }KkH7XksF  
fileFetch.start(); F{<r IR  
}  })w5`?Y  
catch(Exception e){e.printStackTrace ();} a-DE-V Uls  
:Ws3+OI'm3  
Nb{oH+$b  
} `wG&Cy]v  
%n c+VL4  
c Ky%0oTla  
public static void main(String[] args) |b7>kM}"  
{ {k~$\J?.  
new TestMethod(); 17qrBG-/MD  
} ck<4_?1]  
} !*#=7^#  
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