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http断点续传简单实现(java)

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/* \1k79c  
**SiteFileFetch.java 'g}!  
*/ zYH&i6nj  
package NetFox; 8?xE6  
import java.io.*; )W^F2-{  
import java.net.*; ju8> :y8  
1KU! tL  
Cwv9 a^  
public class SiteFileFetch extends Thread { hZ|z|!g0  
yl'u'-Zb6  
Ki;*u_4{  
SiteInfoBean siteInfoBean = null; //文件信息Bean g_;\iqxL  
long[] nStartPos; //开始位置 "BM#4  
long[] nEndPos; //结束位置 fW?vdYF  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 P0;n9>g  
long nFileLength; //文件长度 /p/]t,-j2  
boolean bFirst = true; //是否第一次取文件 |Tv#4st  
boolean bStop = false; //停止标志 pIc#L>{E  
File tmpFile; //文件下载的临时信息 KYB`D.O   
DataOutputStream output; //输出到文件的输出流 s n8Qk=K  
lov!o: dJ  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Na<pwC  
public SiteFileFetch(SiteInfoBean bean) throws IOException 4S7v:1~xe  
{ J"0`%'*/  
siteInfoBean = bean; Sh/08+@+L:  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); .#EFLXs  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");  0HZ{Y9]  
if(tmpFile.exists ()) 6,pnw  
{ Fn wJ+GTu  
bFirst = false; i}cRi&2[  
read_nPos(); ncaT?~u j  
} atj(eg  
else u^&^UxCA  
{ y5vvu>nd  
nStartPos = new long[bean.getNSplitter()]; R|'ybW'Y  
nEndPos = new long[bean.getNSplitter()]; AzPu)  
} QFA8N  
rjK%t|aV^  
hqD*z6aH  
@ JGP,445  
} 49eD1h3'X[  
|44Ploz2b  
M$ wC=b  
public void run() R7%#U`Q^A  
{ +V2F#fI/  
//获得文件长度 \UA[  
//分割文件 (|2t#'m  
//实例FileSplitterFetch C2!|OQ9A2  
//启动FileSplitterFetch线程 n3WlZ!$  
//等待子线程返回 aHD]k8 m z  
try{ pd?M f=>#  
if(bFirst) G0Iw-vf  
{ ldf\;Qk  
nFileLength = getFileSize(); [DuttFX^x  
if(nFileLength == -1) :'Vf g[Uq  
{ )705V|v  
System.err.println("File Length is not known!"); TP*hd  
} vz&|J   
else if(nFileLength == -2) 7P } W *  
{ 9i:L&dN  
System.err.println("File is not access!"); ;[ZEDF5H  
} Y_liA  
else xR~h wj  
{ e1yt9@k,  
for(int i=0;i<nStartPos.length;i++) ,KH#NY]  
{ J4hL_iCQ  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); fuW\bo3  
} 3<Lx&p~%T  
for(int i=0;i<nEndPos.length-1;i++) 6XxvvMA97  
{ y RqL9t  
nEndPos = nStartPos[i+1]; 10Q ]67  
} !aUs>1i  
nEndPos[nEndPos.length-1] = nFileLength; PI {bmZ  
} }{Pp]*I<A  
} 4Z3su^XR  
1C+13LE$U  
/|}EL%a  
//启动子线程 iqsCB%;5  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A`%k:@  
for(int i=0;i<nStartPos.length;i++) U gat1Pz  
{ g&L!1<, p  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 70?\ugxA  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [g |_~h  
nStartPos,nEndPos,i); : $1?i)  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8S TvCH"Z_  
fileSplitterFetch.start(); "x0^#AVg  
} sI=xl  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AYBns]!  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #^0R&) T  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VD*6g%p  
nEndPos = " + nFileLength); .^`{1%  
// fileSplitterFetch[nPos.length-1].start(); ~12EQacOT  
7sCG^&Y  
[(i  
//等待子线程结束 :U|1xgB  
//int count = 0; B`)BZ,#p  
//是否结束while循环 e+7"/icK  
boolean breakWhile = false; u[;\y|75  
NWESP U):w  
0D.Mke )  
while(!bStop) Oi.C(@^(  
{ tAd%#:K  
write_nPos(); ,L2ZinU:  
Utility.sleep(500); l\H=m3Bg  
breakWhile = true; BKCiIfkZ  
5Pc;5 o0C  
P;.W+WN  
for(int i=0;i<nStartPos.length;i++) <dWv?<o  
{ +HpA:]#Y  
if(!fileSplitterFetch.bDownOver)  tU5zF.%  
{ o'aEY<mZ7  
breakWhile = false; QE+g j8  
break; /KaZH R.  
} b~P`qj[  
} Pbn*_/H  
if(breakWhile) x;.Jw 6g  
break; VBlYvZ;$*  
z|J_b"u4  
HVCe;eI  
//count++; eb\K "ec"  
//if(count>4) }0*@fO  
// siteStop(); "S]0  
} 9<?M8_  
4"(Bu/24  
EWhK0Vej=  
System.err.println("文件下载结束!"); 9rX&uP)j^#  
} $99n&t$Y  
catch(Exception e){e.printStackTrace ();} @gEUm_#HTs  
} D/gw .XYL  
.hb:s,0mP  
5 V~oIL  
//获得文件长度 ?4}h&/  
public long getFileSize() xIW3={b3  
{ i^&~?2  
int nFileLength = -1; Vm(y7}Aq{  
try{ 7aRi5  
URL url = new URL(siteInfoBean.getSSiteURL()); p`dU2gV  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?p{Nwl#  
httpConnection.setRequestProperty("User-Agent","NetFox"); y14;%aQN  
Y]_ruDIW  
1-uxC^u?|#  
int responseCode=httpConnection.getResponseCode(); 2,oKVm+  
if(responseCode>=400) ?=7 cF  
{ 2zA4vZkbcw  
processErrorCode(responseCode); :pY/-Cgv  
return -2; //-2 represent access is error *;slV3  
} +o{R _  
M/'sl;  
[S%_In   
String sHeader; O6 3<AY@  
|A~jsz6pI  
P1 8hxXE3  
for(int i=1;;i++) -0 a/$h  
{ f}ji?p  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2]jn '4  
//Utility.log(in.readLine()); Sv#XIMw{,  
sHeader=httpConnection.getHeaderFieldKey(i); XEp{VC@=  
if(sHeader!=null) [!uG1GJ>  
{ 4he GnMD  
if(sHeader.equals("Content-Length")) Zn+.;o)E<  
{ %XDc,AR[  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HZB>{O  
break; 'F3f+YD  
} aiUY>M#|  
} TER=*"!  
else (t K||*u  
break; 7IH@oMvE  
} (N6i4 g6  
} k Z .gO  
catch(IOException e){e.printStackTrace ();} sf qL|8  
catch(Exception e){e.printStackTrace ();} \ a<h/4#|  
k,6f &#x  
/4V#C-  
Utility.log(nFileLength); "Yv_B3p   
.V/Rfq  
.GXBc  
return nFileLength; #U4F0BdA  
} Gr'  CtO  
1CD+B=pQG  
34O `@j0-3  
//保存下载信息(文件指针位置) 4r#= *  
private void write_nPos() 85$m[+md  
{ 8I?Wt W  
try{ [A~xy'T  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]NY~2jmX  
output.writeInt(nStartPos.length); -#[a7',Z;  
for(int i=0;i<nStartPos.length;i++) 6dt]`zv/  
{ z+wA rPxc  
// output.writeLong(nPos); G@\1E+Ip  
output.writeLong(fileSplitterFetch.nStartPos); }5[qo`M  
output.writeLong(fileSplitterFetch.nEndPos);  / }X1W  
} '~<m~UXvD#  
output.close(); #aJ(m&  
} sN*N&XG  
catch(IOException e){e.printStackTrace ();} . B9iLI  
catch(Exception e){e.printStackTrace ();} LVfF[  
} Ecefi pG  
%QGC8Tz  
m+R[#GE8#  
//读取保存的下载信息(文件指针位置)  .Wj;%|  
private void read_nPos() B$ PP&/  
{ py!|\00}  
try{ t;Sb/3  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )h4 f\0  
int nCount = input.readInt(); )gIKH{JYL  
nStartPos = new long[nCount]; 0B/,/KX  
nEndPos = new long[nCount]; Xm}/0g&7  
for(int i=0;i<nStartPos.length;i++) jDfC=a])  
{ _\G"9,)u '  
nStartPos = input.readLong(); 7M!I8C0!aO  
nEndPos = input.readLong(); HxV=F66"  
} I\{ 1u  
input.close(); Y@vTaE^w3  
} 9'giU r  
catch(IOException e){e.printStackTrace ();} n8 i] z  
catch(Exception e){e.printStackTrace ();} @7]yl&LZ  
} !8d{q)JZ  
["93~[[^  
kk@fL  
private void processErrorCode(int nErrorCode) SCHP L.n  
{ vn!3l1\+J  
System.err.println("Error Code : " + nErrorCode); 5h-SCB>P  
} Tod&&T'UW  
GqvpA# i  
'&tG?gb&  
//停止文件下载 zuad~%D<I  
public void siteStop() 85:=4N%  
{ T|eu  
bStop = true; 9igiZmM  
for(int i=0;i<nStartPos.length;i++) Q800y??&J  
fileSplitterFetch.splitterStop(); dI(@ZV{  
:Zbg9`d*  
jh%Eq+#S  
} 2d #1=+V  
} KNvZm;Q6  
//负责部分文件的抓取 gnOt+W8  
**FileSplitterFetch.java y<|7z99L  
*/ O7m(o:t x3  
package NetFox; mb TEp*H  
i {NzV  
>V?eog%~  
import java.io.*; -`kW&I0  
import java.net.*; W0@n/U  
feDlH[$  
t ;;U}  
public class FileSplitterFetch extends Thread { IqaT?+O\?r  
C=L>zOZ  
v\gLWq'  
String sURL; //File URL \5:i;AE  
long nStartPos; //File Snippet Start Position zm5]J  
long nEndPos; //File Snippet End Position wx= $2N6  
int nThreadID; //Thread's ID ?}tFN_X"  
boolean bDownOver = false; //Downing is over *=/ { HvJ  
boolean bStop = false; //Stop identical p Z|V 3  
FileAccessI fileAccessI = null; //File Access interface x_N'TjS^{  
I by\$~V  
&tLgG4pd  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #uG%j  
{ 6$Xzpg(o  
this.sURL = sURL; WYm\)@  
this.nStartPos = nStart; nLZTK&7}  
this.nEndPos = nEnd; pk$l+sNZ=  
nThreadID = id; A5I)^B<(  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rxvx  
} MDZ640-Y  
KK/tu+"  
_ @NL;w:!  
public void run() kzQ+j8.,U  
{ GX!G>  
while(nStartPos < nEndPos && !bStop) pHXm>gTd,J  
{ A@!qv#'  
45@ I*`  
n?!">G  
try{ oi&VgnSk  
URL url = new URL(sURL); HSE!x_$  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +ZaSM~   
httpConnection.setRequestProperty("User-Agent","NetFox"); B dj!ia;H  
String sProperty = "bytes="+nStartPos+"-"; #C74z$  
httpConnection.setRequestProperty("RANGE",sProperty); T= y}y  
Utility.log(sProperty); ["k,QX  
%op**@4/t\  
Q^9_' t}X  
InputStream input = httpConnection.getInputStream(); )Pa'UGY  
//logResponseHead(httpConnection); ah4N|zJ>v  
Ct<udO  
H7&8\ FNa  
byte[] b = new byte[1024]; *MhRW,=  
int nRead; z;,u}u}aI  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m{Wu" ;e  
{ Y1W1=Uc uk  
nStartPos += fileAccessI.write(b,0,nRead); K,;E5  
//if(nThreadID == 1) ?4#Li~q  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F4-$~ v@  
} K*vt;L  
In"ZIKaC  
.GP T!lDc  
Utility.log("Thread " + nThreadID + " is over!"); YNyk1cE  
bDownOver = true;  j|DsG,  
//nPos = fileAccessI.write (b,0,nRead); ` xEx^P^7  
} X Swl Tg  
catch(Exception e){e.printStackTrace ();} oQ/E}Zk@  
} ]KKS"0a  
}  c(f  
T?CdZc.  
~OYiq}g  
//打印回应的头信息 x*\Y)9Vgy  
public void logResponseHead(HttpURLConnection con) { =9,n\85#  
{ zOAd~E  
for(int i=1;;i++) %8B}Cb&2c  
{ A7Cm5>Y_S  
String header=con.getHeaderFieldKey(i); kYP#SH/  
if(header!=null) CAig ]=2'  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :S{BbQ){]  
Utility.log(header+" : "+con.getHeaderField(header)); \j}ZB<.>  
else K^)Eb(4  
break; '5#^i:  
} 1APe=tJ  
} aB2F C$z  
b4%??"&<Y  
g-4M3of  
public void splitterStop() w_"E*9  
{ ONB{_X?  
bStop = true; @ p9i  
} )Yh+c=6 ?  
gS!:+G%  
t9GR69v:?  
} ^,lIK+#Elz  
TPQ%L@^ L+  
wv>^0\o  
/* htO +z7  
**FileAccess.java Y!aSs3c  
*//文件访问(定位,写) kUL' 1!j7  
package NetFox; u"r`3P`  
import java.io.*; ?8H8O %Z8  
G/y5H;<9M  
P[G)sA_"  
public class FileAccessI implements Serializable{ kf\PioD8  
q<x/Hat)  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R^8o^z['6u  
RandomAccessFile oSavedFile; TM__I\+Q  
long nPos; n$A9_cHF7  
imhwY#D  
M!siK2  
public FileAccessI() throws IOException 58}U^IW  
{ 6IN e@  
this("",0); hIYNhZv  
} y1jCg%'H  
)W,aN)1)  
5zK4Fraf  
public FileAccessI(String sName,long nPos) throws IOException K(e$esLs-  
{ 1SQ3-WU s  
oSavedFile = new RandomAccessFile(sName,"rw"); Ljm[?*H#  
this.nPos = nPos; V@.Ior}w  
oSavedFile.seek(nPos); IkL#SgY  
} o)M}!MT  
>jDDQ@  
ozyX$tp  
public synchronized int write(byte[] b,int nStart,int nLen) <`8n^m*  
{ { T/[cu<  
int n = -1; T= 80,  
try{ kUb>^- -K  
oSavedFile.write(b,nStart,nLen); 3,_aAgeE  
n = nLen; o"s)eh  
} W<h)HhyG  
catch(IOException e) u74[>^  
{ `z}?"BW|  
e.printStackTrace (); hE:9{;Gf  
} (fH#I tf  
[~+wk9P  
2"v6 >b%  
return n; >>4qJ%bL  
} + )AG*  
aL\PGdgO  
C!O0xhs  
} % :f&.@'r  
R+hU8 pu  
MVpGWTH@F  
/* ~p6 V,Q  
**SiteInfoBean.java EgEa1l!NSQ  
*/ dM.f]-g  
package NetFox; (' (K9@}  
GhAlx/K  
N@4w! HpJ  
public class SiteInfoBean { B&M%I:i  
SBu"3ym  
4!{KWL`A  
private String sSiteURL; //Site's URL Ot0ap$&  
private String sFilePath; //Saved File's Path TIqtF&@o4  
private String sFileName; //Saved File's Name /$Ir5=B  
private int nSplitter; //Count of Splited Downloading File I.(, hFx;  
{S]}.7`l9(  
olB.*#gA  
public SiteInfoBean() o+iiST JEe  
{//nSplitter的缺省值为5 7DogM".}~Q  
//default value of nSplitter is 5 5+4IN5o]=  
this("","","",5); %@J.{@>  
} LG9+GszX 2  
VcE:G#]5  
JJ-( Sl  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) UkwP  
{ d UE,U=  
sSiteURL= sURL; .<0ye_S'y  
sFilePath = sPath; 98c(<  
sFileName = sName; =`oCLsz=  
this.nSplitter = nSpiltter; )b L'[h  
0@0w+&*"@  
4&lv6`G `  
} D(op)]8  
GRIti9GD  
[T4J{y64Y  
public String getSSiteURL() /|m2WxK)  
{ S&5&];Ag  
return sSiteURL; H\"sgoJ  
} [o#oa k{U  
q CC.^8  
JAnZdfRt  
public void setSSiteURL(String value) wD}l$ & +  
{ .&iawz  
sSiteURL = value; IVnHf_PzF  
} ?/E~/;+7=  
|fJ};RLI"  
Jl8H|<g~/  
public String getSFilePath() ' ,wFTV&  
{ Xh"n]TK  
return sFilePath; .[KrlfI  
} F@jZ ho  
VR8-&N  
V*;(kEqj  
public void setSFilePath(String value) GT.,  
{ np^N8$i:n  
sFilePath = value; dm0R[[7  
} yx8z4*]kH  
wo{gG?B  
`:fZ)$sY  
public String getSFileName()  :A_@,Q  
{ ,Ks8*;#r  
return sFileName; WM$ MPs  
} l~q\3UKlt  
Y=?3 js?O  
;u ({\K  
public void setSFileName(String value) ,.8KN<A2]'  
{ vzAaxk%  
sFileName = value; qH>d  
} oUlY?x1  
@ CL{D:d  
Y;M|D'y+  
public int getNSplitter() SYJD?&C;  
{ ?pmHFlx  
return nSplitter; VQt0  4?  
} 3,3N^nSD  
e2TiBTbQaF  
9d659i C  
public void setNSplitter(int nCount) ^98~U\ar  
{ !sP {gi#=  
nSplitter = nCount; wH&!W~M  
} f|c{5$N!  
} k@J&IJ  
>z>!Luw  
'3fu  
/* s?}e^/"v  
**Utility.java :J@ gmY:C  
*/ + .[ <%  
package NetFox; `5.'_3  
Qx#"q'2  
ql{ OETn#  
public class Utility { |v%YQ R  
%)W2H^  
&)ChQZA  
public Utility() U(g:zae  
{ L|xbR#v  
0RLg:SV  
{rw|#Z>A  
} &%DY\*  
;bib/  
//线程睡眠 8qTys8  
public static void sleep(int nSecond) dn+KH+v  
{ s};{ZAtE  
try{ ?Ep [M:,q  
Thread.sleep(nSecond); K=k"a  
} n M*%o-  
catch(Exception e) }2.`N%[  
{ WX?IYQ+  
e.printStackTrace (); k$R-#f;  
} KwSqKI7]0  
} HCs?iJ  
$a"Oc   
//日志 a~}OZ&PG  
public static void log(String sMsg) 1};Stai'  
{ 9}<ile7^  
System.err.println(sMsg); <0&*9ZeD  
}  "Og7rl  
24*XL,  
Yujiqi]J;  
public static void log(int sMsg) IueFx u  
{ )23H1  
System.err.println(sMsg); IY\5@PVZ  
} "7F?@D$e  
} BLiF 5  
x*U)Y  
/>pI8 g<  
/* _op}1   
**TestMethod.java <)c)%'v  
*/ Fj3a.'  
package NetFox; 0gr/<v  
h2]P]@nW;W  
xj;H&swo  
public class TestMethod { !ons]^km  
qiBVG H  
:>f )g  
public TestMethod() @,7GaK\  
{ ///xx/weblogic60b2_win.exe k)=s>&hl  
try{ jcf7n`L  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YfKdR"i+.  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8^+%I/S$  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 04P}-L,  
fileFetch.start(); ,j_i?Ff  
} !``,gExH  
catch(Exception e){e.printStackTrace ();} u^I|T.w<r6  
j-}O0~Jz  
29] G^f>  
} e2oa($9  
eJX9_6m-  
_|I#{jK  
public static void main(String[] args) zL0pw'4  
{ {ROVvs`  
new TestMethod(); Vv=. -&'  
} |3"KK  
} +lcbi  
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