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http断点续传简单实现(java)

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/* PT\5P&2o@  
**SiteFileFetch.java TxxW/f9D  
*/ Ww8C![ ,  
package NetFox; b<:s{f"t,  
import java.io.*; @ ?e;Jp9  
import java.net.*; lzxn} TO}  
o8Bo%OjE  
SkPv.H0Id  
public class SiteFileFetch extends Thread { ODEy2).  
[ >vS+G  
;gW~+hW^  
SiteInfoBean siteInfoBean = null; //文件信息Bean {P = {)  
long[] nStartPos; //开始位置 ybYSz@7  
long[] nEndPos; //结束位置 ]FFU,me2  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 /Ee0S8!Z!1  
long nFileLength; //文件长度 2<B+ID3qv  
boolean bFirst = true; //是否第一次取文件 P *%bG 4  
boolean bStop = false; //停止标志 MfYe @ ;m  
File tmpFile; //文件下载的临时信息 1noFXzeU3  
DataOutputStream output; //输出到文件的输出流 fcV/co_S6  
[5m;L5  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) E]ZM`bex&  
public SiteFileFetch(SiteInfoBean bean) throws IOException G&3j/5V  
{ 4@8i,q>  
siteInfoBean = bean; `w~ 9/sty  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); tQwbIX-7/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); *DG*&Me  
if(tmpFile.exists ()) nS4~1a  
{ yK}#|b'cM  
bFirst = false; d628@~ Ekn  
read_nPos(); pw(`+x]  
} kWoy%?|RRa  
else />f`X+d  
{ ^2=Jv.2{|  
nStartPos = new long[bean.getNSplitter()]; mTs[3opg  
nEndPos = new long[bean.getNSplitter()]; YY]LK%-  
} i]1[eGF  
o +aB[+  
qrt+{5/t  
2;kab^iv'  
} ,,{Uz)>'W6  
A\SbuRty  
<|m"Q!f  
public void run() KDn`XCnk,  
{ e?f[t*td  
//获得文件长度 *b7v)d#  
//分割文件 "CZ`hx1|^  
//实例FileSplitterFetch `qfVgT=2  
//启动FileSplitterFetch线程 *$hO C%(  
//等待子线程返回 ~xHr/:  
try{ xQmk2S` y  
if(bFirst) Kvk;D ]$  
{ if `/LJsa  
nFileLength = getFileSize(); 8fDnDA.e  
if(nFileLength == -1) jMw;`yh  
{ Gt 2rJ<>  
System.err.println("File Length is not known!"); }. ,xhF[  
} 3w^q0/ GD  
else if(nFileLength == -2) f'#7i@Je  
{ O %)+ w  
System.err.println("File is not access!"); F*]AjD-  
} $jw!DrE  
else ^&cI+xZ2Y  
{ mBnC]$<R  
for(int i=0;i<nStartPos.length;i++) uF< F4m;  
{ xDVzHgbf  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); pf2$%lE  
} 1"!<e$&$X  
for(int i=0;i<nEndPos.length-1;i++) F<^,j7@  
{ ^Yn6kF  
nEndPos = nStartPos[i+1]; 5E.cJ{   
} ^ qE4:|e  
nEndPos[nEndPos.length-1] = nFileLength; )@Bt[mfrVD  
} j.m-6  
} k_y@vW3  
{&2$1p/9'  
O:u^jcXA  
//启动子线程 <89 js87  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \x|(`;{  
for(int i=0;i<nStartPos.length;i++) {yfG_J  
{ kvo741RO6  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kmP0gT{Sj  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0TVO'$Gvi  
nStartPos,nEndPos,i); 5))?,YkrrI  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |5Z@7  
fileSplitterFetch.start(); ff{ESFtD  
} `T~M:\^D  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^:DlrI$  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); - +>~  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9g 2x+@5T^  
nEndPos = " + nFileLength); Z9!goI  
// fileSplitterFetch[nPos.length-1].start(); -`Z5#8P  
xXHz)w  
op"Cc  
//等待子线程结束 }uZh oA  
//int count = 0; hL8QA!  
//是否结束while循环 q Rtgk  
boolean breakWhile = false; .[CXW2k  
4>, <b1Y  
S&]JY  
while(!bStop) r]8B6iV  
{ 4RdpROK  
write_nPos(); B8;ZOLAU  
Utility.sleep(500); d B?I (  
breakWhile = true; H]}- U8}sp  
z3a te^PJF  
,@[Q:fY  
for(int i=0;i<nStartPos.length;i++) VF 6@;5p  
{ pX!S*(Q{  
if(!fileSplitterFetch.bDownOver) ;jnnCXp>  
{ q4U?}=PD  
breakWhile = false; fT 8"1f|w  
break; w0Us8JNGz  
} Gb8LW,$IT-  
} VJ1si0vWtq  
if(breakWhile) o 'yR^`  
break; X1A;MA@0Ro  
&5zUk++  
i 5-V$Qh  
//count++; |e+I5  
//if(count>4) BT`6v+,h7k  
// siteStop(); *h]qh20t  
} /e\} qq  
]YwIuz6]  
xu_Tocvop  
System.err.println("文件下载结束!"); "qwRcuHY  
} iRPd=)  
catch(Exception e){e.printStackTrace ();} @++ X H}  
} ( XE`,#  
~A"ODLgU9  
tCA |sN  
//获得文件长度 )V9$ P)  
public long getFileSize() 5*4P_q(AxD  
{ TmO\!`  
int nFileLength = -1; 0w(<pNA  
try{  ~LkReQI  
URL url = new URL(siteInfoBean.getSSiteURL()); r^Gl~sX  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5"@<7/2qI  
httpConnection.setRequestProperty("User-Agent","NetFox"); {uw'7 d/  
bZ%[ON5OY  
xb1)ZJH  
int responseCode=httpConnection.getResponseCode(); 8mx5K-/,y^  
if(responseCode>=400) '+-R 7#  
{ yqCy`TK8  
processErrorCode(responseCode); ^=W%G^jJy  
return -2; //-2 represent access is error SD TX0v  
} $\0j:<o  
:X@;XEol~  
spFsrB  
String sHeader; \`4}h[  
DY,Sfh;tp  
nA+[[(6  
for(int i=1;;i++) S: /ShT  
{ 9}3W0F;  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /$ L;m  
//Utility.log(in.readLine()); 1!=$3]l0Lj  
sHeader=httpConnection.getHeaderFieldKey(i); -4X,x  
if(sHeader!=null) \Z57UNI  
{ UVU}  
if(sHeader.equals("Content-Length")) ~r|.GY  
{ 9X=#wh,q  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e2Xx7*vS  
break; v*#Z{)r  
} )vy<q/o+  
} O|av(F9  
else %yptML9  
break; ,riwxl5*E/  
} B#q5Ut  
} 62Jn8DwAT  
catch(IOException e){e.printStackTrace ();} HlV3rYh  
catch(Exception e){e.printStackTrace ();} u}#rS%SF*  
p>R F4  
y(N-1  
Utility.log(nFileLength); BPi>SI0  
R2M,VK?Wx  
RV&2y=eb  
return nFileLength; G#l zB`i  
} 9:@os0^O  
|5g*pXu{  
  I]  
//保存下载信息(文件指针位置) d(fgv  
private void write_nPos() TcRnjsY$  
{ {4:En;  
try{ #=$4U!yL  
output = new DataOutputStream(new FileOutputStream(tmpFile)); a^sR?.+3  
output.writeInt(nStartPos.length); *~fN^{B'!  
for(int i=0;i<nStartPos.length;i++) 4e*0kItC  
{ %zX'u.}8#  
// output.writeLong(nPos); f+/^1~^  
output.writeLong(fileSplitterFetch.nStartPos); 6bqJM#y@  
output.writeLong(fileSplitterFetch.nEndPos); 21cIWvy  
} 2|Tt3/Rn  
output.close(); ,PIdPaV--  
} h8S%Q|-  
catch(IOException e){e.printStackTrace ();} b^A&K@[W#,  
catch(Exception e){e.printStackTrace ();} 0BE%~W  
} 2%WZ-l!i  
 eKu&_q  
6`+DBr  
//读取保存的下载信息(文件指针位置) #0^Q UOp  
private void read_nPos() R o%S_!  
{ ]qpcA6%a|  
try{ ;tKL/eI  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GWP"i77y0s  
int nCount = input.readInt(); kZn!]TseN  
nStartPos = new long[nCount]; }Efp{E  
nEndPos = new long[nCount]; vTB*J,6.  
for(int i=0;i<nStartPos.length;i++) q F}5mUcZ4  
{ rj{'X  /  
nStartPos = input.readLong(); pX*mX]  
nEndPos = input.readLong(); d2(eX\56Z  
} {CGk5`g~  
input.close(); $p9XXZ"*  
} .h*&$c/l  
catch(IOException e){e.printStackTrace ();} 29Gej Lg |  
catch(Exception e){e.printStackTrace ();} Y,)9{T  
} r3*wH1n  
g%\e80~1(  
pp{%\td  
private void processErrorCode(int nErrorCode) NT8%{>F`  
{ gW*ee  
System.err.println("Error Code : " + nErrorCode); ^?juY}rZ=|  
} *|`'L  
X;}_[ =-  
o}Xp-P   
//停止文件下载 2y<d@z:K  
public void siteStop() bNL E=#ro  
{ }hBv?B2/1  
bStop = true; 0+S:2i/G  
for(int i=0;i<nStartPos.length;i++) WMI/Y 9N  
fileSplitterFetch.splitterStop(); `zep`j&8^  
6XX5K@  
4&&j7$aV  
} EIF[e|kZ<  
} oxad}Y  
//负责部分文件的抓取 t zV"|s=o  
**FileSplitterFetch.java JG4&eK$-  
*/ neZ_TT/3K  
package NetFox; )p!dql K  
esLY1c%"/  
#}jf TM  
import java.io.*; x K_$^c.  
import java.net.*; :z"Uw*  
-D V;{8U4  
3^`bf=R  
public class FileSplitterFetch extends Thread { w=f8UtY9@A  
Ni0lj:  
b UWtlg  
String sURL; //File URL 1hMk\ -3S  
long nStartPos; //File Snippet Start Position I#A`fJ  
long nEndPos; //File Snippet End Position j+Tk|GRab  
int nThreadID; //Thread's ID JLG5`{  
boolean bDownOver = false; //Downing is over e`_3= kI  
boolean bStop = false; //Stop identical V];RQWs  
FileAccessI fileAccessI = null; //File Access interface .y'OoDe  
K}$PIW  
ev+N KUi=  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vhUuf+P*  
{ (d!vm\-PH  
this.sURL = sURL; >|rL0  
this.nStartPos = nStart; Bq2}nDP  
this.nEndPos = nEnd; LLU>c]a  
nThreadID = id; d3 N %V.w  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9r)5d&,6  
} rAQ^:q  
$~9U-B\  
( NiuAy  
public void run() oYqC"g&4Z  
{ m<076O4|`  
while(nStartPos < nEndPos && !bStop) hA~}6Qn  
{ D@W m-  
KztF#[64W^  
lL83LhE}<  
try{ G-:DMjvN  
URL url = new URL(sURL); WK<pZ *x  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @yek6E&9  
httpConnection.setRequestProperty("User-Agent","NetFox"); GvVuFS>y  
String sProperty = "bytes="+nStartPos+"-"; YE-kdzff  
httpConnection.setRequestProperty("RANGE",sProperty); 6!gGWn5>}  
Utility.log(sProperty); >! c^  
|0 Zj/1<$  
+~[19'GH  
InputStream input = httpConnection.getInputStream(); <4>6k7W  
//logResponseHead(httpConnection); bRIb'%=+GA  
<LLSUk/  
}u|0  
byte[] b = new byte[1024]; 1-b,X]i  
int nRead; \ tQi7yj4  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ep'C FNbtW  
{ xt-;7  
nStartPos += fileAccessI.write(b,0,nRead); y24 0 +;a  
//if(nThreadID == 1) fh2Pn!h+  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w}2yi#E[  
} dvxH:,  
7"S|GEs:  
kPxrI=  
Utility.log("Thread " + nThreadID + " is over!"); g xLA1]>{  
bDownOver = true; Z> &PM06  
//nPos = fileAccessI.write (b,0,nRead); QVFa<>8/md  
} JEAqSZak#  
catch(Exception e){e.printStackTrace ();} Z2LG/R  
} {!EbGIh  
} "%Rx;xw|  
P|6m%y  
,Wdyg8&.  
//打印回应的头信息 )^r4|WYyt  
public void logResponseHead(HttpURLConnection con) D)!k  
{ b>waxQxjS  
for(int i=1;;i++) #}vcffgZ  
{ nGuF, 0j  
String header=con.getHeaderFieldKey(i); WIhf*LF"  
if(header!=null) ?Dfgyz  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *X)OdU  
Utility.log(header+" : "+con.getHeaderField(header)); B)c.`cfr*\  
else #6YNgJNk  
break; a-kU?&* y  
} !WIL|\jbh  
} lvFHr}W  
&XZ>}^lD^  
PSy=O\  
public void splitterStop() ]w')~yk  
{ .rMGI "  
bStop = true; y%T'e(5Ed  
} 9> (8r+  
\@80Z5?n  
4sva%Up  
} WIb U^WJ0  
7sFjO/a*  
)X7ZX#ttH  
/* mM95BUB  
**FileAccess.java 1 8&^k|  
*//文件访问(定位,写) S]9xqiJW  
package NetFox; Q"(i  
import java.io.*; yX)2 hj:s  
x2nNkd0h  
?HBc7$nW  
public class FileAccessI implements Serializable{ ?Jx8z`(  
?=fJu\;  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gFW1Nm_DJ  
RandomAccessFile oSavedFile; PgxU;N7Y  
long nPos; 0ogTQ`2Z:  
9x:c"S*  
<4VUzgX2  
public FileAccessI() throws IOException 3 =S.-  
{ f:=?"MX7  
this("",0); $A-b-`X  
} rA_e3L@v#[  
=?/J.[)<*  
\?}ZXKuJj  
public FileAccessI(String sName,long nPos) throws IOException ABx0IdOcI  
{ {Ji[d.cY  
oSavedFile = new RandomAccessFile(sName,"rw"); fdPg{3x*k  
this.nPos = nPos; iveWau292  
oSavedFile.seek(nPos); <7)@Jds\  
} /FQumqbnt  
gsZCWT  
he!e~5<@y  
public synchronized int write(byte[] b,int nStart,int nLen) ]pFYAe ?  
{ u9?85  
int n = -1; 7o ;}"Y1  
try{ _p90Zm-3X  
oSavedFile.write(b,nStart,nLen); d_OHQpfK  
n = nLen; Ypp>7J/  
} v/(< fI^  
catch(IOException e) Dn9Ta}miTO  
{ T3Tk:r  
e.printStackTrace (); 0chBw~@*s  
} d*!,McBn  
7?F0~[eGG  
W>h[aVTO  
return n; 6r^(VT  
} =b6Q2s,i  
\.}* s]6  
5Rc 5/m  
} G<>`O;i  
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2!l)% F`  
/* /#.6IV(  
**SiteInfoBean.java &"25a[x{B  
*/ tcmG>^YM  
package NetFox; {@({po  
]ul]L R%.  
aP2  
public class SiteInfoBean { VFRUiz/C  
!K3 #4   
sg2T)^*V  
private String sSiteURL; //Site's URL ( vgoG5  
private String sFilePath; //Saved File's Path (?$}Vp  
private String sFileName; //Saved File's Name $n>.;CV  
private int nSplitter; //Count of Splited Downloading File 8+lM6O ~!  
<@JK;qm>S  
RW%e%  
public SiteInfoBean() 3d \bB !  
{//nSplitter的缺省值为5 |r6<DEg  
//default value of nSplitter is 5 X}_kLfP/9  
this("","","",5); &;*jMu6  
} &i6WVNGy  
k;q|pQ[  
Xul<,U~w6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c"6<p5j!  
{ ,7<5dIdZ  
sSiteURL= sURL; ECQ>VeP  
sFilePath = sPath; <Ms,0YKx  
sFileName = sName; bT0CQ_g21  
this.nSplitter = nSpiltter; h_fA  
=C u !  
"Bn!<h}mg  
}  #6@7XC  
>e'6RZRLA  
@G^ l`%  
public String getSSiteURL() Nx,.4CI  
{ /tDwgxJ  
return sSiteURL; OZDnU6  
} e=Kf<ZQt  
sBB>O@4  
FG'F]f c%  
public void setSSiteURL(String value) r +d%*Dx  
{ .kyp5CD}4  
sSiteURL = value; vm 1vX;  
} "0pu_  
IL*C/y  
l/#;GYB]  
public String getSFilePath() 4f'1g1@$  
{ p^MV< }kk  
return sFilePath; 8<{)|GoqB  
} ]u G9WT6l  
L;wzvz\+  
hZ[,.  
public void setSFilePath(String value) Q6]SsV?x  
{ o@XhL9  
sFilePath = value; hCuUX)>Bt  
} j/ow8Jmc*  
,_F@9Up  
^FIpkhw  
public String getSFileName() s<h]2W  
{ :I[nA?d[&  
return sFileName; STtjkZ6  
} sZxf.  
$!H;,Jxv  
.}=gr+<bf  
public void setSFileName(String value) s\@RJ[(<  
{ Mj2`p#5wKh  
sFileName = value; lhZXq!2p  
} >;:235'(M  
7A<X!a  
"**Tw'  
public int getNSplitter() 4"at~K` Q  
{ Py_yIwQqg  
return nSplitter; `O/1aW1  
} RoS&oGYqR  
0go{gUI  
Y HSdaocp  
public void setNSplitter(int nCount) FhpS#, Y$  
{ 1P;J%.{  
nSplitter = nCount; KP,#x$Bg  
} 1Tm,#o  
} "}fJ 2G3  
bvzNur_  
mmRxs1 0$  
/* rom`%qp^  
**Utility.java +#ufW%ZG  
*/ -Ri/I4Xj  
package NetFox; <A@}C+  
e98f+,E/  
|zd+ \o  
public class Utility { AWo\u!j  
UNY O P{  
!Pd@0n4  
public Utility() "{>BP$Jz  
{ n-P<y  
1u>[0<U~E  
,yf2kU  
} !p #m?|Km  
N5_`  
//线程睡眠 wo>7^ZA  
public static void sleep(int nSecond) ,58XLu  
{ {8]Yqx)1]]  
try{ @:s (L]  
Thread.sleep(nSecond); )seeBm-`  
} Wz{,N07Q#{  
catch(Exception e) ^1`Mz<  
{ %j $r"  
e.printStackTrace (); ]WFr5  
} Z#uxa  
} (r*"}"ZG  
c6-~PKJL  
//日志 KJ (|skO  
public static void log(String sMsg) =2XAQiUR\  
{ -,:^dxE'  
System.err.println(sMsg); }ZqnsLu[)  
} )?y${T   
}jdMo83  
@qUgp*+{  
public static void log(int sMsg) ~  p~  
{ 6K Cv  
System.err.println(sMsg); )>"|<h.2]  
} tW-wO[2  
} " l;=jk]  
7! sR%h5p  
:Eb=jWA  
/* s$g3__|Y  
**TestMethod.java E5iNuJj=f  
*/ CWdpF>En  
package NetFox; #M ;j*IBl*  
Dbl3ef  
Nb3uDA5R  
public class TestMethod { WQiIS0BJ *  
^tF lA)  
[b:0j-  
public TestMethod() 3QhQpPk) ,  
{ ///xx/weblogic60b2_win.exe k^@dDLr"  
try{ #IvHxSo&  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3-Bz5sj9  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0?,<7}"<X  
SiteFileFetch fileFetch = new SiteFileFetch(bean); S\M+*:7  
fileFetch.start(); KOhK#t>H@0  
} awB+B8^s  
catch(Exception e){e.printStackTrace ();} U%rEW[j  
A<}nXHs-  
YQ|o0>  
} e+~@"^|  
g|Tkl  
-JfqY?Ue_2  
public static void main(String[] args) `c)[aP{vN  
{ 9y}/ G  
new TestMethod(); )k[{re  
} Xl,707  
} %`bn=~T^  
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