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http断点续传简单实现(java)

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/* mHjds77e  
**SiteFileFetch.java Q#8}pBw  
*/ w}VS mt$F  
package NetFox; R4G$!6Ld  
import java.io.*; 'NF_!D  
import java.net.*; l$D]*_ jc,  
EotZ$O=  
(#FWA<o  
public class SiteFileFetch extends Thread { ItGi2'}  
6Clxe Lk  
57e'a&}e  
SiteInfoBean siteInfoBean = null; //文件信息Bean i,NU%be  
long[] nStartPos; //开始位置 8`Fo^c=j  
long[] nEndPos; //结束位置 WJBi#(SY  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 .a\b_[+W  
long nFileLength; //文件长度 09<O b[%h  
boolean bFirst = true; //是否第一次取文件 Ql sMMIax  
boolean bStop = false; //停止标志 xg %EQ  
File tmpFile; //文件下载的临时信息 +HNY!fv9  
DataOutputStream output; //输出到文件的输出流 XYIZ^_My  
[8AGW7_  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Uj&2'>MJ$  
public SiteFileFetch(SiteInfoBean bean) throws IOException B Jp\a7`;  
{ ?1JVzZ4H  
siteInfoBean = bean; @K/}Ob4   
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); =vLeOX  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); \tTZ N  
if(tmpFile.exists ()) =8S*t5  
{ zK893)  
bFirst = false; R'f|1mt  
read_nPos(); 1lZl10M:f  
} (yWU9q)5  
else mh;<lW\K/Z  
{ b[,J-/;JNL  
nStartPos = new long[bean.getNSplitter()]; y&Sl#IQ L  
nEndPos = new long[bean.getNSplitter()]; )O~LXK=b  
} Iih~W&  
v'0A$`w`  
 b=v  
z><=F,W  
} =zBcfFii`w  
6}"P m  
!a?$  
public void run() o@j]yA.5)  
{ [mph iH/  
//获得文件长度 IFNs)*  
//分割文件 so}(*E&(a  
//实例FileSplitterFetch 6j{9\ R  
//启动FileSplitterFetch线程 pMM,ox"  
//等待子线程返回 {vh}f+2  
try{ FOiwB^$ >  
if(bFirst) ScU?T<u:i  
{ W|J8QNL?jm  
nFileLength = getFileSize(); ?{l}35Q.@  
if(nFileLength == -1) :4s{?IY)l  
{ :GXiA  
System.err.println("File Length is not known!"); ?.E6Ube  
} fCTdM+t  
else if(nFileLength == -2) (&R /ns~  
{ HbQ `b  
System.err.println("File is not access!"); NXsDn&&O  
} 3jQy"9f  
else Sc'z vlq  
{ s>(OK.o  
for(int i=0;i<nStartPos.length;i++) }eh<F^  
{ 7K3S\oPej  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); -b+VzVJZ  
} qeLfO  
for(int i=0;i<nEndPos.length-1;i++) x!GHUz*:uz  
{ X@KF}x's  
nEndPos = nStartPos[i+1];  " Mzb  
} h<2o5c|  
nEndPos[nEndPos.length-1] = nFileLength; x`K<z J   
} "&*O7cs$pA  
} 8o43J;mA  
AE!DftI  
h^R EBPe  
//启动子线程 zu}oeAQc$  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s<VNW  
for(int i=0;i<nStartPos.length;i++) @NlE2s6a  
{ +-YMW;5  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7/QQ&7+NkS  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9 I>qD  
nStartPos,nEndPos,i);  gSQq  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6Mu_9UAl`  
fileSplitterFetch.start(); 1'DD9d{ qN  
} sFv68Ag+  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z18T<e  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nNJU@<|{*  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?g gl8bzA  
nEndPos = " + nFileLength); |?k3I/;  
// fileSplitterFetch[nPos.length-1].start(); rOd<nP^`\  
^=:e9i3u  
o?(({HH  
//等待子线程结束 x0 1n  
//int count = 0; (os}s8cIh  
//是否结束while循环 !h3 $C\  
boolean breakWhile = false; d-Vttxa6  
c,nE@~ul2  
I3`WY-uv  
while(!bStop) 5%,5Xe4p  
{ Hhx"47:  
write_nPos(); 3V ~871:-~  
Utility.sleep(500); wSoIU,I  
breakWhile = true; ssaEAm:  
Ji4xor  
pw|f4c7AH  
for(int i=0;i<nStartPos.length;i++) B1)gudP`  
{ J%ng8v5ex  
if(!fileSplitterFetch.bDownOver) 4po zTe  
{ y%%D="  
breakWhile = false; |Iei!jm  
break; x=>B 6o-f  
} 2F* spu  
} d-/{@   
if(breakWhile) 3cfJ(%'X  
break; "(bnr0  
YaiogA  
u^.7zL+  
//count++; MLwh&I9)  
//if(count>4) i) v ]  
// siteStop(); {8+FxmH  
} ROcI.tL  
8R?X$=$]!.  
"Bl ]_YPv  
System.err.println("文件下载结束!"); ;e,_F/@`  
} x(oL\I_Z  
catch(Exception e){e.printStackTrace ();} to9~l"n.s  
} }j<:hD QP  
y4sKe:@2  
}-YM>q  
//获得文件长度 4WCWu}  
public long getFileSize() dH:z _$Mg  
{ 7<FI[  
int nFileLength = -1; [7x,&  
try{ #dy z  
URL url = new URL(siteInfoBean.getSSiteURL()); o/0cd  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "#zSk=52z  
httpConnection.setRequestProperty("User-Agent","NetFox"); We%HdTKT  
qTc-Z5  
9C&Xs nk  
int responseCode=httpConnection.getResponseCode(); <Y%km[Mh  
if(responseCode>=400) 38ac~1HjE  
{ Gy}WZ9{  
processErrorCode(responseCode); dy/\>hu  
return -2; //-2 represent access is error 5cahbx1"  
} r'bctFsD  
Xwz9E!m  
F}9!k LR  
String sHeader; xvo""R/g8  
pJ8;7u  
K1y]  
for(int i=1;;i++) E"i<fr T  
{ `)5,!QPQ7u  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a,eR'L<"*-  
//Utility.log(in.readLine()); 'T=$Q%Qv  
sHeader=httpConnection.getHeaderFieldKey(i); akR+QZ,)  
if(sHeader!=null) ])`+ 78  
{ q!UN<+k\h  
if(sHeader.equals("Content-Length")) 0,a/t jSr  
{ 25EuVj`zL  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +yC]f b  
break; X}jWNN  
} MU_8bK9m  
} i'XW)n  
else N RB>X  
break; E2.@zY|:  
} HJ5 Ktt  
} KDTG9KC  
catch(IOException e){e.printStackTrace ();} * AsILK0  
catch(Exception e){e.printStackTrace ();} ^YVd^<cE  
'v|R' wi\  
jLc"1+  
Utility.log(nFileLength); &Bn> YFu  
Mw{0A\6  
p7SX,kpt>  
return nFileLength; kT7x !7C  
} <HYK9{Q  
Cn\5Vyrl  
h>0R!Rl8  
//保存下载信息(文件指针位置) op!ft/Yyb  
private void write_nPos() :vsBobiJ  
{ F7o#KN*.]  
try{ 1#nR$  
output = new DataOutputStream(new FileOutputStream(tmpFile)); cXcrb4IKD  
output.writeInt(nStartPos.length); pTzwyj!SD  
for(int i=0;i<nStartPos.length;i++) [K5#4k  
{ TNi4H:\  
// output.writeLong(nPos); MxXf.iX&  
output.writeLong(fileSplitterFetch.nStartPos); +V2\hq[{  
output.writeLong(fileSplitterFetch.nEndPos); %P3|#0yg0  
} #.Q3}[M  
output.close(); 9^yf'9S1  
} |ZJ<J)y  
catch(IOException e){e.printStackTrace ();} D./!/>@f  
catch(Exception e){e.printStackTrace ();} rN$U%\.I  
} *U<l$gajq  
$!?tJ@{  
Kp]\r-5UD>  
//读取保存的下载信息(文件指针位置) z2.9l?"rfQ  
private void read_nPos() l g0 'qH8  
{ 30BFwNE  
try{ XIep3l*  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eT!*_.' e  
int nCount = input.readInt(); -'!K("  
nStartPos = new long[nCount]; $m hIX A.  
nEndPos = new long[nCount];  AqqD!  
for(int i=0;i<nStartPos.length;i++) st7\k]J\  
{ MC'2;,  
nStartPos = input.readLong(); (ncm]W  
nEndPos = input.readLong(); jH5VrN*Q  
} ^ <$$h  
input.close(); s (2/]f$  
} 4z;@1nN_8a  
catch(IOException e){e.printStackTrace ();} ,0pCc<  
catch(Exception e){e.printStackTrace ();}  }q$6^y  
} OuZPgN  
{fd/:B 7T  
Z 91{*?  
private void processErrorCode(int nErrorCode)  L- '{   
{ k vu SE  
System.err.println("Error Code : " + nErrorCode); pq T+lai)#  
} ]3KMFV}  
hRU5CH/!  
v47S9Vm+  
//停止文件下载 CjQ)Bu *4  
public void siteStop() "e-RV  
{ "VIoV u  
bStop = true; KfPYH\ 0  
for(int i=0;i<nStartPos.length;i++) `F(ghC  
fileSplitterFetch.splitterStop(); tz^2?wO  
',_E;(  
w=;Jj7}L  
} }CM</  
} }EMds3<  
//负责部分文件的抓取 R(^2+mV?  
**FileSplitterFetch.java 7A,lQh  
*/ xs}3=&c(  
package NetFox; _o+z#Fnz  
M+|J;caX  
DN X-\  
import java.io.*; 7Rq|N$y.3  
import java.net.*; 5 LX'fL7zU  
#^>Md59N  
15l{gbCW  
public class FileSplitterFetch extends Thread { IG(1h+5 R(  
pzcl@  
kq4ii`zi8  
String sURL; //File URL ! ^ DQX=1  
long nStartPos; //File Snippet Start Position id?B<OM  
long nEndPos; //File Snippet End Position h>a/3a$g  
int nThreadID; //Thread's ID ~+)sL1lx  
boolean bDownOver = false; //Downing is over + g*s%^(E  
boolean bStop = false; //Stop identical <Pnz$nH:e  
FileAccessI fileAccessI = null; //File Access interface Sb|9U8h  
>WZ_) `R  
6OPYq*|  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,_iR  
{ >^Z==1  
this.sURL = sURL; F,.dC&B  
this.nStartPos = nStart; AZ7m=Q97  
this.nEndPos = nEnd; ~u.( (GM  
nThreadID = id; +7V4mF!u  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }o:sU^Pwa  
} } \?]uNH  
2R`dyg  
?= R C?K  
public void run() 2mt S\bAF  
{ {/2 _"H3:  
while(nStartPos < nEndPos && !bStop) |=rb#z&  
{ 3;'RF#VL  
*dpKo&y  
xm*6I  
try{ 05ZF>`g*  
URL url = new URL(sURL); 8WP|cF]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pIhy3@bY  
httpConnection.setRequestProperty("User-Agent","NetFox"); Hs#q 7  
String sProperty = "bytes="+nStartPos+"-"; W1\F-:4L@  
httpConnection.setRequestProperty("RANGE",sProperty); Ve9*>6i&-4  
Utility.log(sProperty); \s@7pM=(  
84f~.45  
0_f6Qrcj  
InputStream input = httpConnection.getInputStream();  N3m~nEj  
//logResponseHead(httpConnection); "Nh}_jO  
)KbzgmLr  
K^Ixu~  
byte[] b = new byte[1024]; 50R&;+b  
int nRead; O?OG`{k  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U?e.)G  
{ 2'-!9!C  
nStartPos += fileAccessI.write(b,0,nRead); sKniqWi  
//if(nThreadID == 1) sMDHg  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }1BpIqee  
} d8Sr,t+  
]b&O#D9  
#HyE-|_C  
Utility.log("Thread " + nThreadID + " is over!"); M@a=|N~  
bDownOver = true; x&d:V  
//nPos = fileAccessI.write (b,0,nRead); &fRZaq'2R  
} =8W'4MC  
catch(Exception e){e.printStackTrace ();} :(TOtrK@  
} =C4!h'hz  
} p->b Vt  
+'ADN!(B_  
\2OjIEQQ  
//打印回应的头信息 P>wTp)  
public void logResponseHead(HttpURLConnection con) *V[6ta'  
{ *R_mvJlT  
for(int i=1;;i++) ,1ceNF#oL  
{ @E !`:/k  
String header=con.getHeaderFieldKey(i); Hq!|(  
if(header!=null) j1i<.,0g  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;0JK>c ]#  
Utility.log(header+" : "+con.getHeaderField(header)); e"^n^_9  
else `&/~%>  
break; Z9p`78kYyh  
} *Hed^[sO  
} ( SiwO.TZ  
4<<T#oW.:G  
_J ZlXY  
public void splitterStop() p;P cD  
{ }~+_|  
bStop = true; 7T/hmVi_  
} +2Wijrn  
)9~-^V0A^>  
%"=qdBuk  
} vE$n0bL2  
>pj)va[Q  
<F&53N&Zc  
/* R.)w l  
**FileAccess.java met`f0jw  
*//文件访问(定位,写) Y<)9TU:D!  
package NetFox; rZkl0Y;n\  
import java.io.*; 5hg ^K^ZZ  
+WfO2V.  
-esq]c%3  
public class FileAccessI implements Serializable{ Y8@TY?  
gK",D^6T*Y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f@aFs]xV  
RandomAccessFile oSavedFile; h$_5)d~  
long nPos; oBI@.&tG}  
GSaU:A  
~(Xzm  
public FileAccessI() throws IOException  Jknit  
{ bc%N !d  
this("",0); c?7 Wjy  
} 2/f!{lz](  
HE.YfD)  
TBu[3X%  
public FileAccessI(String sName,long nPos) throws IOException z8*{i]j  
{ 4u+4LB*  
oSavedFile = new RandomAccessFile(sName,"rw"); D\ kd6  
this.nPos = nPos; 2y#[uSqB  
oSavedFile.seek(nPos); M0Vs9K=  
} h:~ 8WV|  
Q/y"W,H#  
]v|n'D-?  
public synchronized int write(byte[] b,int nStart,int nLen) V4tObZP3Ff  
{ AB[#  
int n = -1; K/IG6s;Xj  
try{  zPW_  
oSavedFile.write(b,nStart,nLen); QvvH/u  
n = nLen; V)#rP?Y  
} g;._Q   
catch(IOException e) C~q&  
{ 9Pjw< xt  
e.printStackTrace (); |N%#;7  
} 1qN+AT  
W_Eur,/`  
w+G+&ak<  
return n; &+Yoob]P  
}  ie4BE'  
u[+/WFH  
U "kD)\  
} 'l&bg8K9  
/;9iDjG  
P`]p&:  
/* VB&`g<  
**SiteInfoBean.java 0o_wy1O1,  
*/ -_+,HyJP  
package NetFox; O]%Vh l  
j5~nLo2  
R~!md  
public class SiteInfoBean { NjP7?nXSx  
\Rz-*zr&  
y6`zdB  
private String sSiteURL; //Site's URL Z?j4WJy-[  
private String sFilePath; //Saved File's Path 2YhtD A  
private String sFileName; //Saved File's Name `Yw:<w\4C  
private int nSplitter; //Count of Splited Downloading File KreF\M%Ke  
5sI9GC  
#{x4s?   
public SiteInfoBean() pL pBP+i  
{//nSplitter的缺省值为5 I`4k5KB;  
//default value of nSplitter is 5 m'YYkq(5%Z  
this("","","",5); B0dv_'L}L  
} X(dHh O  
6 TSC7jO  
+_v#V9?  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mz?1J4rt  
{ Fa-F`U@h(m  
sSiteURL= sURL; rUWC=?Q  
sFilePath = sPath; ^<w3i?KPW  
sFileName = sName; {1m.d;(1  
this.nSplitter = nSpiltter; >NjgLJh  
3w$Ib}7   
5KRI}f  
} H`EsFKw\%  
hYY-Eq4TC  
U8GvUysB!  
public String getSSiteURL() !7y:|k,ac  
{ k\A[p\  
return sSiteURL; M$MFUGS'  
} [&K"OQ^\2h  
N= {0A  
ZP;WXB`  
public void setSSiteURL(String value) t^SND{[WcM  
{ gQ=l\/ H  
sSiteURL = value; `~+[pY 1r  
} YT\.${N  
r"W,G /;h  
^zVW 3 Y q  
public String getSFilePath() #xfPobQ>il  
{ &l _NCo2  
return sFilePath; dA=T+u  
} t:yJ~En]=  
9KDm<Q-mf  
 YW'l),Z  
public void setSFilePath(String value) {LoNp0i1a  
{ *4?%Y8;bF6  
sFilePath = value; 5%;=(Oig  
} N5|wBm>m  
\>p\~[cxt  
*@zya9y9q  
public String getSFileName() zIy&gOX  
{ Xn* >qm  
return sFileName; 8Y&_X0T|  
} se`^g ,]P  
ql(~3/kA_  
)bR`uV9<  
public void setSFileName(String value) [6cf$FS9  
{ )A=&3Ui)ab  
sFileName = value; M:d} P  
} =v49[i  
 MKZq*  
>o|.0aw<  
public int getNSplitter() B> V)6\   
{ w*krPaT3  
return nSplitter; N`rz>6,k1  
} 6<{XwmM  
7 jiy9 [  
*(CV OY~  
public void setNSplitter(int nCount) $[{YE[a  
{ EVW\Z 2N.  
nSplitter = nCount; 2b^E8+r9  
} ">x"BP  
} JE ''Th}  
E4qQ  
b3l~wp6>  
/* #?klVK&e/  
**Utility.java yLEA bd%+  
*/ -AZ\u\xCB  
package NetFox; R-OQ(]<*  
7p[NuU*Gg  
(%SKTM  
public class Utility { %%qg<iO_  
Da&Brm   
2"8qtG`Et  
public Utility() ` 3h,Cy^  
{ |ohCA&k%;  
v9XevLs  
=} flmUv~  
} E?cf#;2h8m  
]3I@5}5%  
//线程睡眠 m)e~HP7M  
public static void sleep(int nSecond) DQ9}( '^  
{ z(Q 5?+P  
try{ IA^*?,AZy  
Thread.sleep(nSecond); ]@ N::!m  
} $n_ax\15  
catch(Exception e) AGK{t+`  
{ dr^MW?{a\  
e.printStackTrace (); 2*TPW  
} nZ8jBCh  
} ]7J*(,sp  
/A1qTG=Br  
//日志 cd]def[d  
public static void log(String sMsg) A&L2&ofV&q  
{ Wh^wKF~%  
System.err.println(sMsg); X{tfF!+iy  
} rL|9Xru  
.9@y*_ 9  
g![?P"i^t  
public static void log(int sMsg) Hl=M{)q@   
{ p61F@=EL  
System.err.println(sMsg); @f`s%o  
} iG+=whvL  
} H/$oGhvl  
'.IR|~Y  
ASUL g{  
/* V~]&1  
**TestMethod.java ^EcwY- Qr  
*/ ; ~#uH7k  
package NetFox; k`NXYf:  
g [c ^7  
{"mb)zr  
public class TestMethod { >N-l2?rE  
".sRi  
kS< 9cy[O  
public TestMethod() nJcY>Rp?  
{ ///xx/weblogic60b2_win.exe QS%t:,0lp  
try{ z@U5  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DTz)qHd#X  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i^}ib RQbN  
SiteFileFetch fileFetch = new SiteFileFetch(bean); g96]>]A<{  
fileFetch.start(); F&$~]R=&  
} /TY=ig1z  
catch(Exception e){e.printStackTrace ();} x bD]EC  
g]jCR*]  
g<^-[w4/  
} ->`R[k  
];*? `}#  
!XQ)>T^G5  
public static void main(String[] args) *&tv(+P  
{ T4h&ly5 f  
new TestMethod(); oD=+  
} lD6PKZ\RIj  
} mO&zE;/[  
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