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http断点续传简单实现(java)

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/* %I%OHs  
**SiteFileFetch.java ~J|B  
*/ Q^oB`)k  
package NetFox; p+xjYU4^C  
import java.io.*; e>b|13X  
import java.net.*; .^[{~#Pc*  
C\1x3  
`4t*H>:y  
public class SiteFileFetch extends Thread { 5uL!Ae  
$1bzsB|^  
Y:]m~-T  
SiteInfoBean siteInfoBean = null; //文件信息Bean tS3{y*yi  
long[] nStartPos; //开始位置 WC wM+D  
long[] nEndPos; //结束位置 ~JDVoS;>jU  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 w\5;;9_#  
long nFileLength; //文件长度 9S<at MB  
boolean bFirst = true; //是否第一次取文件 !<4=@  
boolean bStop = false; //停止标志 SG-Xgr@  
File tmpFile; //文件下载的临时信息 RhSoD.Da  
DataOutputStream output; //输出到文件的输出流 QlH,-]N$L  
<U2Un 0T  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 3t:/Guyom8  
public SiteFileFetch(SiteInfoBean bean) throws IOException KO=H!Em\l  
{ Kbqx)E$iL  
siteInfoBean = bean; 4So ,m0v  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); je5GZFQw  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); k6^!G"  
if(tmpFile.exists ()) :<R"Kk@  
{ ]+@I] \S4  
bFirst = false; $/$ 5{<  
read_nPos(); C{FE*@U.  
} hta y-  
else {3|h^h_R  
{ 7tU=5@M9D  
nStartPos = new long[bean.getNSplitter()];  sf'+;  
nEndPos = new long[bean.getNSplitter()]; 7H_*1_%ZQ  
} *T0!q#R  
yMKVF`D*  
t@3y9U$  
OEXa^M4x   
} E)Cdw%}^  
[D<"qT^*z6  
?9:~d#p  
public void run() ]"VxEpqhM  
{ bt 0Q6v5  
//获得文件长度 {7LNQGiJ  
//分割文件 :Wd@Qy?;  
//实例FileSplitterFetch 5HW'nhE  
//启动FileSplitterFetch线程 <g{d >j  
//等待子线程返回 xcE<|0N :  
try{ nlR7V.  
if(bFirst) NrWgaPO)i  
{ &4jc3_UKV  
nFileLength = getFileSize(); 9"b  =W@  
if(nFileLength == -1) 9{XV=a v  
{ uN9J?j*ir  
System.err.println("File Length is not known!"); ,?`Zrxe[  
} 3s$vaV~(a  
else if(nFileLength == -2) -=a,FDeR  
{ nn{PhyK  
System.err.println("File is not access!"); _?c7{  
} 4-~S"T8<u  
else roHJ$~q?  
{ i 3i  
for(int i=0;i<nStartPos.length;i++) {6gY6X-R  
{ Ql{:H5  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); "aJf W  
} Q;0 g  
for(int i=0;i<nEndPos.length-1;i++) 3\0,>L9ET@  
{ }BJR/r  
nEndPos = nStartPos[i+1]; D;+sStZK3  
} P8n |MN  
nEndPos[nEndPos.length-1] = nFileLength; K)s{D ] B  
} p\ _&  
} o ^Ro 54i  
,HtX D~N  
Q> J9M` a  
//启动子线程 }C<$q  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yp"h$  
for(int i=0;i<nStartPos.length;i++) _j}jh[M  
{ rqz`F\A;%  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n1;zml:7_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O7# 8g$ZIv  
nStartPos,nEndPos,i); ,V.Bzf%=O  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =RjseTS  
fileSplitterFetch.start(); 2dJP|T9H  
} 7L$\S[E  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *`~]XM@H  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pMLTXqL  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .1A/hAdU  
nEndPos = " + nFileLength); =a!_H=+4  
// fileSplitterFetch[nPos.length-1].start(); \<W/Z.}/  
F6gU9=F1<  
y4j\y ? T8  
//等待子线程结束 H_d^Xk QZ  
//int count = 0; -DL"Yw}  
//是否结束while循环 dd:vQOF;  
boolean breakWhile = false; ZXC_kmBN/  
}}gtz-w  
4{CeV7  
while(!bStop) 0Q!/A5z  
{ u Xo?  
write_nPos(); cN%@ nW0i  
Utility.sleep(500); nUf0TkA  
breakWhile = true; |wGmu&fY  
^:Fj+d  
F-%Hw  
for(int i=0;i<nStartPos.length;i++) *IWWD\U  
{ FqXE6^  
if(!fileSplitterFetch.bDownOver) ;2[o>73F  
{ kV@?Oj.&I,  
breakWhile = false; rBZ0Fx$/[  
break; W}'l8z]   
} Mew,g:m:  
} %Z+FX,AK  
if(breakWhile) 3#N`n |UgC  
break; g+3_ $qIQ+  
UM:]Qba In  
tX~ *.W:  
//count++; *NCkC ~4  
//if(count>4) R^&.:;Wi>  
// siteStop(); 2"IDz01ne  
} \Sv8c}8  
@Io@1[kj  
'9@AhiNV  
System.err.println("文件下载结束!"); #T++5G  
} K8RV=3MBLD  
catch(Exception e){e.printStackTrace ();} l- $5CO  
} U<I]_]  
t 09-y  
?.^n,[2  
//获得文件长度 _0"s6D$  
public long getFileSize() c'SjH".[  
{ @ )Nw>/; o  
int nFileLength = -1; `wKd##v'@  
try{ Af Y ]i  
URL url = new URL(siteInfoBean.getSSiteURL()); U3~rtc*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y 'Ah*h  
httpConnection.setRequestProperty("User-Agent","NetFox"); A$70!5*  
bMB*9<c~  
<RuLIu  
int responseCode=httpConnection.getResponseCode(); {'sp8:$a  
if(responseCode>=400) %\T#Ik~3  
{ m\G45%m  
processErrorCode(responseCode); *R3^:Y&  
return -2; //-2 represent access is error <b-OdOg  
} |cgc^S/~H  
{$Z S 2 7  
Tly*i"[&  
String sHeader; SvQ!n4 $  
*yYeqm  
8(g}/%1mt3  
for(int i=1;;i++) p# JPLCs  
{ _6-N+FI  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); HT7I~]W  
//Utility.log(in.readLine()); -f["1-A  
sHeader=httpConnection.getHeaderFieldKey(i); )zkr[;j~`  
if(sHeader!=null) r-o+NV  
{ @cc}[Uw4B  
if(sHeader.equals("Content-Length")) lJdrrR)wg  
{ ai"N;1/1O|  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8Y [4JXUK  
break; v^aI+p6  
} 9XmbHS[0V  
} pgBIYeY,  
else YRQ?:a{H  
break; %OOy90b2  
} i,,mt_/,  
} P"+R:O\!g  
catch(IOException e){e.printStackTrace ();} XZT|ID_u"  
catch(Exception e){e.printStackTrace ();} O Ke 9/._  
JqV}$E"M2  
ogqKM_  
Utility.log(nFileLength); :9f 9Z7M  
AjJ/t4<  
kn+@)3W:*  
return nFileLength; |E &|6h1  
} v%7Gh -P  
W@RD bsc  
Z-3("%_$/  
//保存下载信息(文件指针位置) gfiFRwC`v  
private void write_nPos() w|f@sB>j  
{ Hi^ Z`97c  
try{ rJ(AO'=  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Vi#[k n'  
output.writeInt(nStartPos.length); wb ^>/  
for(int i=0;i<nStartPos.length;i++) 6Ev+!!znu  
{ Tnas$=J  
// output.writeLong(nPos); WO$8j2!~#  
output.writeLong(fileSplitterFetch.nStartPos); F`>qg2wO  
output.writeLong(fileSplitterFetch.nEndPos); x"A\ Z-xxz  
} = u&dU'@q  
output.close(); f9t+x+ Z  
} I#;.; %u  
catch(IOException e){e.printStackTrace ();} 3gYtu-1  
catch(Exception e){e.printStackTrace ();} <?h(Dchq  
} r`i.h ^2De  
8X/SNRk6p  
G 2uM6  
//读取保存的下载信息(文件指针位置) Z/q'^PB p  
private void read_nPos() yji>vJHu  
{ ?*6Q ;.f<  
try{ ni6zo~+W]  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }(oWXwFb&W  
int nCount = input.readInt(); xeKm} MN]S  
nStartPos = new long[nCount]; \H 5t-w=  
nEndPos = new long[nCount]; 8%p+:6kP5  
for(int i=0;i<nStartPos.length;i++) pZ]&M@Ijp  
{ <) -]'@*c  
nStartPos = input.readLong(); 5=  V29  
nEndPos = input.readLong(); t ?05  
} 5"bg 8hL  
input.close(); [LrO"9q(  
} zb s7G  
catch(IOException e){e.printStackTrace ();} VVfTFi<  
catch(Exception e){e.printStackTrace ();} O^8=Xj#}  
} (yoF  
7!;zkou  
V P(JV  
private void processErrorCode(int nErrorCode) 7Kpv fyL{  
{ G?!8T91;  
System.err.println("Error Code : " + nErrorCode); *+(eH#_2/  
} AC!yc(^<  
nI] zRduC  
S5r.so  
//停止文件下载 ^S 45!mSb  
public void siteStop() n8JM 0 U-  
{ aSI%!Vg.  
bStop = true; MRT<hB  
for(int i=0;i<nStartPos.length;i++) ]Bs{9=2  
fileSplitterFetch.splitterStop(); FGeKhA 8jT  
"whs?^/  
fcy4?SQ.<i  
} /N,\st  
} , eSpt#M  
//负责部分文件的抓取 7jGfQ  
**FileSplitterFetch.java 0}po74x*r  
*/ CZ>Ujw=&k  
package NetFox; qRz /$|.  
nRT ]oAi  
])q,mH  
import java.io.*; uX%$3k  
import java.net.*; w-C%,1F,/  
TaF;P GjVw  
 QB !%  
public class FileSplitterFetch extends Thread { <U8w#dc  
T7o7t5*  
q s:TR  
String sURL; //File URL C=2DxdZG  
long nStartPos; //File Snippet Start Position bf.yA:~U  
long nEndPos; //File Snippet End Position nWh f  
int nThreadID; //Thread's ID hZWkw{c  
boolean bDownOver = false; //Downing is over \7IT[<Se  
boolean bStop = false; //Stop identical (iIzoEpb8W  
FileAccessI fileAccessI = null; //File Access interface x:h)\%Dg<  
)`6OSB  
[.6bxK  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #o,FVYYj  
{ cucT |y  
this.sURL = sURL; PDLps[a  
this.nStartPos = nStart; =5:S"WNj  
this.nEndPos = nEnd; 74&{GCL  
nThreadID = id; -9Ygn_M  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 aj=-^iGG  
} /1uGsE+[  
h iK}&  
;=1[D  
public void run() 4UK>Vzn  
{ fPstS ez   
while(nStartPos < nEndPos && !bStop) F!w|5,)  
{ KTwP.!<v  
?{xD{f$  
cob??|,\m  
try{ |?hsMN  
URL url = new URL(sURL); 8k+k\V{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [ $"  
httpConnection.setRequestProperty("User-Agent","NetFox"); #K iqV6E  
String sProperty = "bytes="+nStartPos+"-"; K@Xj)  
httpConnection.setRequestProperty("RANGE",sProperty); @VyNe(U  
Utility.log(sProperty); l}k'ZX4  
mx#)iHY  
sCp)o,;  
InputStream input = httpConnection.getInputStream(); DghqSL ^s  
//logResponseHead(httpConnection); =NSunW!  
Zv* uUe  
AYfe_Dj  
byte[] b = new byte[1024]; nc1?c1s,f  
int nRead; vZs~=nfi#|  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3+q-yP#X  
{  j8]M}Q$  
nStartPos += fileAccessI.write(b,0,nRead); P>$+XrTE  
//if(nThreadID == 1) |;^$IZSsz  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lR mVeq:  
} }SyK)W5Y  
THB[(3q  
e@S\7Ks  
Utility.log("Thread " + nThreadID + " is over!"); q8,,[R_  
bDownOver = true; k ~F ,n  
//nPos = fileAccessI.write (b,0,nRead);  *I}_g4  
} hS>=p O+y  
catch(Exception e){e.printStackTrace ();} Qstd;qE~  
} wD W/?lT&  
} M(uJ'Ud/!  
E>O@Bv  
de[NIDA;`  
//打印回应的头信息 0-57_";%Q  
public void logResponseHead(HttpURLConnection con) zQUNvPYM  
{ 25r3[gX9`  
for(int i=1;;i++) '@IReMl  
{ 2=%]Ax"R  
String header=con.getHeaderFieldKey(i); f hNJB0  
if(header!=null) !89hO4 0r  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gvL*]U7  
Utility.log(header+" : "+con.getHeaderField(header)); madbl0[y.  
else woF {O)~X  
break; )J2UNIgN  
} ~=<uYv?0s  
} Cv4nl7A'  
$iA:3DM07  
,]y_[]636  
public void splitterStop() J aJ/ |N  
{ e AaS }g 0  
bStop = true; ~-uDN)  
} '(ZT }N  
OYb:);o,iE  
JNP6qM  
} ^t$uDQ[hA  
;Cjj_9e,:  
dxH.  
/* y(E<MRd8V  
**FileAccess.java Z|)1ftcC  
*//文件访问(定位,写) {~G~=sC$  
package NetFox; 4r86@^c*  
import java.io.*; _'^_9u G  
g_?Q3  
0kw)-)=  
public class FileAccessI implements Serializable{ 6$zd2N?  
,DEcCHr,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 563ExibH  
RandomAccessFile oSavedFile; N^k& 8  
long nPos; 7{9M ^.}  
ic l]H  
=EU;%f  
public FileAccessI() throws IOException zZey  
{ d#W^S[[  
this("",0); Lf%}\0:  
} ,4B8?0sH|  
}r;=<mc,O  
YN7`18u  
public FileAccessI(String sName,long nPos) throws IOException &5G@YQD1e  
{ q]*jTb  
oSavedFile = new RandomAccessFile(sName,"rw"); cm q4w&x/  
this.nPos = nPos; e-1G\}E  
oSavedFile.seek(nPos); 'q RQO(9&m  
} +oHbAPs8  
ou`KkY||  
qG9j}[d'  
public synchronized int write(byte[] b,int nStart,int nLen) $D D esy3  
{ /s+S\ djk  
int n = -1; -"^xg"  
try{ rhly.f7N=A  
oSavedFile.write(b,nStart,nLen); u g;~dhe~  
n = nLen; ~&+a.@T  
} eZ0-O /_i  
catch(IOException e) EB6X Yr  
{ 7@m+ y  
e.printStackTrace (); }OTJ{eG  
} z2!4w +2  
%%)y4>I  
x3.,zfWs  
return n; j *;.>akY7  
} \~t!M~H  
TmM~uc7mj  
%az6\"n  
} xO,;4uE  
YD{N)v  
?{5}3a bB`  
/* X|QokAR{$>  
**SiteInfoBean.java .])X.7@x  
*/ X\i;j!;d  
package NetFox; S/RChg_L5  
(Jk[%_b>_  
Gvvw:]WgF  
public class SiteInfoBean { wfcR[  
1?.NJ<)F  
{vZAOz7#  
private String sSiteURL; //Site's URL u`Y~r<?P(  
private String sFilePath; //Saved File's Path 4x@W]*i  
private String sFileName; //Saved File's Name  obPG]*3  
private int nSplitter; //Count of Splited Downloading File }7P[%(T5  
p{ ``a=  
GCv1x->  
public SiteInfoBean() _>?.MUPB  
{//nSplitter的缺省值为5 Q:T9&_|  
//default value of nSplitter is 5 n.R"n9v`  
this("","","",5); cRNVqMpg  
} GdrVH,j  
S 2W@;XvV  
^\Q%VTM  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M=SrZ,W  
{ >J_ P[v  
sSiteURL= sURL; {))Cb9'  
sFilePath = sPath; |YfJ#Agm+  
sFileName = sName; ?[Ma" l>  
this.nSplitter = nSpiltter; 6:`[Fi  
&2O~BIRE  
>m{>0k(^`  
} [nrD4  
QXl~a%lB  
jpTk@  
public String getSSiteURL() oL<5hN*D  
{ _#{qDG=  
return sSiteURL; 4mpcI  
} G|"m-.9F  
UISsiiG(  
.3cD.']%  
public void setSSiteURL(String value) % I2JS  
{ gFfKK`)}D'  
sSiteURL = value; \ Z5160  
} peOoZdJd  
5P 5Tgk  
cR*~JwC:  
public String getSFilePath() AE Elaq.B  
{ ,068IEs  
return sFilePath; +ef>ek  
} nNnfcA&W  
=En1?3?  
_9Rj,  
public void setSFilePath(String value) R\/tKZJjb  
{ _5$L`&  
sFilePath = value; crSqbL  
} Y4X`(\A  
@e$EwCV,  
jR@>~t[}o  
public String getSFileName() $d,{I8d  
{ s'IB{lJ9  
return sFileName; l m(mY$B*_  
} >$=l;jO`n  
xh!T,|IR  
Gm0}KU  
public void setSFileName(String value) C',uY7}<  
{ pr,1pqiAf  
sFileName = value; AI9922}*  
} TgJ6O,0  
\$F#bIjC  
HMmVfGp]  
public int getNSplitter() y-gXGvZ  
{ Pj{I} 4P`  
return nSplitter; =U8+1b  
} )a `kL,  
g@Y]$ey%A  
kVG+Wr7l0F  
public void setNSplitter(int nCount) HnsLYY\  
{ BqdpJIr  
nSplitter = nCount; e+>$4Jq  
} n1PvZ~^3  
} yw89*:A6  
bMv[.Z@v(  
\%V !& !'  
/* S?OCy4dk:  
**Utility.java Z/4bxO=m  
*/ "s(|pQh;  
package NetFox; ~lqNWL^l  
Ap|g[J  
OIjG`~Rx  
public class Utility { DNyt_5j&:  
:2:%  
C#3&,G W  
public Utility() 0V`~z-#  
{ ZjrBOb  
x;LO{S4Z  
b5f+q:?{  
} -mLu!32I<  
'UZ i>Ta  
//线程睡眠 $*Wa A`(U  
public static void sleep(int nSecond) &h=f  
{ fGe"1MfU  
try{ W2M[w_~QE  
Thread.sleep(nSecond); %dhrXK5  
} 1' dZ?`O  
catch(Exception e) ;sz_W%-;@  
{ +OtD@lD`!  
e.printStackTrace (); ((^v sKT  
} `A o"fRv#  
} +$/NTUOP  
#yEkd2Vy{  
//日志 vu*9(t)EC  
public static void log(String sMsg) Q7/Jyx|  
{ bBGg4{  
System.err.println(sMsg); lEb H4 g  
} $~?)E;S  
e:_[0#  
mmCGIX  
public static void log(int sMsg) lTtc#  
{ C+mPl+}w  
System.err.println(sMsg); D}-HWJQA3  
} P*hYh5a  
} !FB2\hiM  
1CV ?  
9[`\ZGWD  
/* f2v~: u  
**TestMethod.java (#>Q#Izr  
*/ x`'s  
package NetFox; v3kT~uv  
47A[-&y*X  
j)juvat  
public class TestMethod { 57;( P  
s!Iinc^p  
h///  
public TestMethod() Mt%Q5^  
{ ///xx/weblogic60b2_win.exe I7t}$ S6  
try{ Qkw_9  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V|{~9^  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gI@nE:(m  
SiteFileFetch fileFetch = new SiteFileFetch(bean); &b2@+/ F  
fileFetch.start(); .v9i|E=<~  
}  BrZ17  
catch(Exception e){e.printStackTrace ();} Q^?$2ck=  
{?X +Yw  
 ;CV'  
} RtDTcaW/  
g|4>S<uC  
^?0?*  
public static void main(String[] args) %(s2{$3  
{ ma"M?aM  
new TestMethod(); A v;NQt8ut  
} 1 7 iw`@  
} %uo#<Ny/ I  
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