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http断点续传简单实现(java)

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/* ;mH O#  
**SiteFileFetch.java c ;_ T  
*/ [@d$XC]Qz  
package NetFox; 70bI}/u  
import java.io.*; s%F}4W2s  
import java.net.*; 0G`_dMN  
Sc03vfmo"N  
h8@8Q w  
public class SiteFileFetch extends Thread { 9}p>='  
LV|ZZ.d h  
bH4'j/3  
SiteInfoBean siteInfoBean = null; //文件信息Bean H]&a}WQ_  
long[] nStartPos; //开始位置 N~7xj?  
long[] nEndPos; //结束位置 (T;4'c  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 +vOlA#t%Z  
long nFileLength; //文件长度 f P'qUN  
boolean bFirst = true; //是否第一次取文件 Qvc "?yx8}  
boolean bStop = false; //停止标志 I&JVY8'  
File tmpFile; //文件下载的临时信息 ny# ?^.1  
DataOutputStream output; //输出到文件的输出流 *J[3f]PBmR  
zbQ-l1E  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) O.61-rp  
public SiteFileFetch(SiteInfoBean bean) throws IOException ]7<}EG  
{ { FVLH:{U^  
siteInfoBean = bean; y/U(v"'4U  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); h| q!Qsnj'  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); =`RogjbP  
if(tmpFile.exists ()) W/03L, 1  
{ TZ#(G  
bFirst = false; I5EKS0MQ!  
read_nPos(); ;',hwo_LBf  
} UjCQ W:[  
else .m--# r  
{ 1, 5"sQ$  
nStartPos = new long[bean.getNSplitter()]; 'a]4]d  
nEndPos = new long[bean.getNSplitter()]; |'@c ~yc  
} R9=K/  
BET3tiHV  
tBR"sBiws  
.Up\ 0|b  
} b{T". @b  
n-X;JYQW  
dnRS$$9#  
public void run() SvR:tyF  
{ 5/U|oZM"  
//获得文件长度 \#1*r'V8  
//分割文件 l#40VHa?S  
//实例FileSplitterFetch 06hzCWm#  
//启动FileSplitterFetch线程 &.dC%  
//等待子线程返回 }M3f ?Jv  
try{ +Fn^@/?yC  
if(bFirst) TVaD',5_V%  
{ I~:vX^%9  
nFileLength = getFileSize(); 6yDc4AX  
if(nFileLength == -1) +{b!,D3sa*  
{ Vz=ByyC  
System.err.println("File Length is not known!"); g&z)y  
} BGk>:Z`  
else if(nFileLength == -2) < 5 Ft3sd  
{ $e(]L(o;  
System.err.println("File is not access!"); N(*Xjy+PX  
} bCv=Uo,+6  
else [ " n+2;  
{ U;o$=,_p  
for(int i=0;i<nStartPos.length;i++) nFRU-D$7  
{ x,CTB  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); y. xt7 F1  
} U9?fUS  
for(int i=0;i<nEndPos.length-1;i++) |2i=oX(r|  
{ +"sjkdum1  
nEndPos = nStartPos[i+1]; .G ^-. p  
} \a_75^2  
nEndPos[nEndPos.length-1] = nFileLength; kIC $ai6.  
} [uJfmrEH  
} M2pe*z  
(-<s[VnXP  
l**gM  
//启动子线程 w^ AY= Fc  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9.:]eL  
for(int i=0;i<nStartPos.length;i++) fwkklg^  
{ A"S F^p  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fbTq?4&Q  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qjcPJ  
nStartPos,nEndPos,i); 6KvoHo  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z[ NO`!<  
fileSplitterFetch.start(); Q)/V >QW  
} lQ8h-Tz  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^"\3dfzKM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <W>T!;4!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D]?eRO9'  
nEndPos = " + nFileLength); @5["L  
// fileSplitterFetch[nPos.length-1].start(); "jUM}@q5  
z[cs/x  
<:n !qQS6  
//等待子线程结束 R&-Vm3mc3  
//int count = 0;  &x":  
//是否结束while循环 ?Z0NHy;5  
boolean breakWhile = false; \80W?9qj  
r_x|2 A oO  
~E8L,h~  
while(!bStop) #J Ay  
{ eP?=tUB!S  
write_nPos(); ir{li?kV  
Utility.sleep(500); 5LF&C0v  
breakWhile = true; bQvhBa?  
D<QE?:#  
< dD)>Y.  
for(int i=0;i<nStartPos.length;i++) r6b;v2!8  
{ cXd?48O  
if(!fileSplitterFetch.bDownOver) ee}HQ.}Ja  
{ ? PI2X.6  
breakWhile = false; }fV+Kd$CB  
break; fi,h`mdT?  
} 8v ZY+Q >  
} ; u@& [  
if(breakWhile) t@;r~S b  
break; 5r)]o'? s  
G%HuB5:u  
R<)^--n  
//count++; ( kKQs")  
//if(count>4) ^. p d'  
// siteStop(); +_T`tmQ  
} lz [s  
@2`$ XWD  
!U "?vSl  
System.err.println("文件下载结束!"); <k'%rz  
} &)$}Nk  
catch(Exception e){e.printStackTrace ();} vTl7x  
} }T~ }W8H  
%K[u  
X{u\|e{  
//获得文件长度 -z~;f<+I`  
public long getFileSize() c gOkm}h  
{ \Q!I;  
int nFileLength = -1; &cSZ?0R  
try{ YApm)O={  
URL url = new URL(siteInfoBean.getSSiteURL()); p.|M:C\xL  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6Bf aB:  
httpConnection.setRequestProperty("User-Agent","NetFox"); @OGHS}-\  
rizWaw5E!8  
k^#+Wma7  
int responseCode=httpConnection.getResponseCode(); TY`t3  
if(responseCode>=400) #/0d  
{ i}gsxq%  
processErrorCode(responseCode); [vTk*#Cl4  
return -2; //-2 represent access is error $.F.xYS9IJ  
} _]t^F9l  
' 4.T1i,  
a{@gzB  
String sHeader; })y B2Q0  
]99@Lf[^f  
xl ]1TB@  
for(int i=1;;i++) `LOW)|6r`  
{ =mYwO=:D  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O8k+R@  
//Utility.log(in.readLine()); JFu9_=%+  
sHeader=httpConnection.getHeaderFieldKey(i); _$P1N^}Zs  
if(sHeader!=null) n09P!],Xa  
{ rHp2I6.0a  
if(sHeader.equals("Content-Length")) IAi|4,y_L  
{ x K ;#C  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~7>D>!!  
break; LUzn7FZk  
} c<ORmg6  
} lSG]{  
else a];1)zVA6  
break; Ku?1QDhrF*  
} ;~GBD]  
} 1<;VD0XX  
catch(IOException e){e.printStackTrace ();} i:|e#$x  
catch(Exception e){e.printStackTrace ();} _>E=.$  
2QgD<  
oc"7|YG  
Utility.log(nFileLength); \DcO .`L  
FGzn|I  
X@ S~D7|ja  
return nFileLength; q.bx nta"  
} $kBcnk  
<~zPt&C]V  
:n,x?bM  
//保存下载信息(文件指针位置) M.67[Qj~"u  
private void write_nPos() <-DQ(0xg  
{ /s@j{*Om  
try{ s+E: 7T9P  
output = new DataOutputStream(new FileOutputStream(tmpFile)); bT MgE Y  
output.writeInt(nStartPos.length); 5KTPlqm0qF  
for(int i=0;i<nStartPos.length;i++) .q<5OE(f  
{ SQJ +C%   
// output.writeLong(nPos); Mq='|0,  
output.writeLong(fileSplitterFetch.nStartPos); (SMk !b]}  
output.writeLong(fileSplitterFetch.nEndPos); srhI%Zj  
} dVSQG947i:  
output.close(); 9t!Agxm  
} $;rvKco)%  
catch(IOException e){e.printStackTrace ();} ?&=JGk^eJ  
catch(Exception e){e.printStackTrace ();} "?^#+@LV  
} M<r]a{Yv  
Gkm {b[  
*).!  
//读取保存的下载信息(文件指针位置) 1&RB=7.h  
private void read_nPos() 8@/MrEOW#  
{ hi/Z>1ZOX  
try{ B,] AfH  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [Z^26/5a  
int nCount = input.readInt(); Y+h ?HS  
nStartPos = new long[nCount]; s Fx0  
nEndPos = new long[nCount]; .hJcK/m  
for(int i=0;i<nStartPos.length;i++) Dq-[b+bm  
{ <cxe   
nStartPos = input.readLong(); Zb&"W]HSf  
nEndPos = input.readLong(); ZiPz~G0[^  
} b&6lu4D  
input.close(); rX0 ?m:&m  
} B`YD>oCN  
catch(IOException e){e.printStackTrace ();} 5,+fM6^V  
catch(Exception e){e.printStackTrace ();} sR^b_/ElxT  
} 4";NT;_q5  
h]vEXWpG]  
gvr&7=p  
private void processErrorCode(int nErrorCode) xo4lM  
{ y&/bp<Z  
System.err.println("Error Code : " + nErrorCode); sN K^.0  
} V.ETuS;  
!<out4Mz"  
kgI8PybY  
//停止文件下载 ke k/C`7  
public void siteStop()  T\#Gc4  
{ SLNq%7apx  
bStop = true; Sk-Q 4D^  
for(int i=0;i<nStartPos.length;i++) Ly z8DwZ  
fileSplitterFetch.splitterStop(); U'u_'5 {  
~NB|BwAh  
CM7NdK?I  
} \58bz<u"  
} U "r)C;5  
//负责部分文件的抓取 ;NQ}c"9  
**FileSplitterFetch.java ky&wv+7  
*/ N 'n0I^Y1A  
package NetFox; u}P:9u&h6X  
BLAF{vVaf  
my/KsB  
import java.io.*; FzykC  
import java.net.*; QNXoAx%I  
_.E{>IFw  
AxeQv'e  
public class FileSplitterFetch extends Thread { 6"NtVfui  
X(BX+)YR  
M!i*DU+SE  
String sURL; //File URL *sau['Ha  
long nStartPos; //File Snippet Start Position fg lN_  
long nEndPos; //File Snippet End Position 2%pU'D:  
int nThreadID; //Thread's ID _BONN6=*y  
boolean bDownOver = false; //Downing is over e*}:t H  
boolean bStop = false; //Stop identical ysPm4am$  
FileAccessI fileAccessI = null; //File Access interface l*{Bz5hc  
HCCq9us  
/ !y~Q|<|=  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6=Wevb5YJ  
{ ( P=WKZMPN  
this.sURL = sURL; zg'.fUZ  
this.nStartPos = nStart; [#YzU^^Ib  
this.nEndPos = nEnd; e"*1l>g  
nThreadID = id; $:# :"  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |KZX_4   
} uF1&m5^W  
L8H:, } 2  
X&h?1lMJ /  
public void run() Mlr'h}:H  
{ ~d3@x\I?  
while(nStartPos < nEndPos && !bStop) 3ZI:EZ5  
{ oRJ!TAbD  
nLmF5.&  
J"@X>n  
try{ Ux{0)"fj  
URL url = new URL(sURL); ZJ~0o2xZ'  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jt #HbAY  
httpConnection.setRequestProperty("User-Agent","NetFox"); ?3qp?ea  
String sProperty = "bytes="+nStartPos+"-"; X y`2ux+>/  
httpConnection.setRequestProperty("RANGE",sProperty); hW9!  
Utility.log(sProperty); KeB??1S  
/9,'.  
.'$8Hj;@  
InputStream input = httpConnection.getInputStream(); '9zKaL  
//logResponseHead(httpConnection); dG8mE&$g  
c5uC?b].  
6k![v@2R  
byte[] b = new byte[1024]; xB[W8gQ6fa  
int nRead; GmE`YW  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H "5,To  
{ E:k]Z  
nStartPos += fileAccessI.write(b,0,nRead); e igVT4  
//if(nThreadID == 1) ^*+M9e9Z  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z@o6[g/*Q  
} (C1~>7L  
CE!cZZ  
>,tJq %  
Utility.log("Thread " + nThreadID + " is over!"); bfEH>pQ>#  
bDownOver = true; xK)<7 63q>  
//nPos = fileAccessI.write (b,0,nRead); 2y|n!p T  
} ]~VuY:abH  
catch(Exception e){e.printStackTrace ();} -QR]BD%J*[  
} Qx3eEt@X5]  
} ]=ZPSLuEm%  
'h 7x@[|  
if*~cPnN  
//打印回应的头信息 aMxj{*v7  
public void logResponseHead(HttpURLConnection con) $tXW/  
{ l_$>$d  
for(int i=1;;i++) 2{Dnfl'k  
{ <#;5)!gr{  
String header=con.getHeaderFieldKey(i); Mk=*2=d  
if(header!=null) h-sO7M0E]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !syyOfu`}  
Utility.log(header+" : "+con.getHeaderField(header)); fAz4>_4  
else :VWN/m  
break; |(TEG.<g  
} Y2'HP)tfIw  
} WNb2"W  
\x:U`T  
\IYv9ScAx  
public void splitterStop() 6rWq hIaI  
{ R,["w9 8a  
bStop = true; \ltS~E uWU  
} xLLTp7b(  
'p\&Mc_Gu  
Cg%Owe/E?0  
} ki}Li*)7  
!.MbPPNp  
a&2x;diF  
/* EYZ&%.Sy5  
**FileAccess.java OwPHp&{ Y  
*//文件访问(定位,写) lZe-A/E  
package NetFox; ujN~l_ 4  
import java.io.*; 9n\v{k=  
[5M!'  
7<2?NLE8*  
public class FileAccessI implements Serializable{ yd45y}uS;F  
U}=H1f,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节  %\B?X;(  
RandomAccessFile oSavedFile; 6/(Z*L"~6k  
long nPos; <3=k  
JE$ $6X  
]i `~J  
public FileAccessI() throws IOException ,s@S`KS0  
{ 91T[@p  
this("",0); eR3MU]zF  
} +K;%sAZy  
b+CvA(*  
gKPqU@$*  
public FileAccessI(String sName,long nPos) throws IOException Zyz)`>cB  
{ [E}pU8.t6  
oSavedFile = new RandomAccessFile(sName,"rw"); Nk F2'Z{$+  
this.nPos = nPos; RcI0n"Gi_  
oSavedFile.seek(nPos); !+Sd%2o  
} ry* 9  
q'biTn]2  
1gYvp9Ma  
public synchronized int write(byte[] b,int nStart,int nLen) tf9a- s  
{ IueI7A  
int n = -1; i.ivHV~ -  
try{ X%B2xQM 5  
oSavedFile.write(b,nStart,nLen); A2fuNV_  
n = nLen; kh>i#9Ie  
} oT}Sh4Wt.  
catch(IOException e) GMob&0l8_  
{ gGbqXG^  
e.printStackTrace (); uv7tbI"r  
} &v+Hl ^  
>LEp EMJ\  
h&b s`  
return n; *AYjMCo  
} ]jP 0Z#  
)Vx C v  
-9"[/  
} (G{2ec:?  
HR?a93  
0:>C v<N  
/* o7:"Sl2AD  
**SiteInfoBean.java .[o?qCsw  
*/ O'W[/\A56M  
package NetFox; sRGIHT#  
!f8]gTzN  
|\q@XCGei  
public class SiteInfoBean { =$vy_UN  
|DoD.?v  
T7 XbbU  
private String sSiteURL; //Site's URL Oj.xJ(uX+v  
private String sFilePath; //Saved File's Path YoRD9M~iG~  
private String sFileName; //Saved File's Name ot,e?lF  
private int nSplitter; //Count of Splited Downloading File aw'o=/a8  
0kld77tn 2  
#TY[\$BHs  
public SiteInfoBean() Jd/XEs?<q  
{//nSplitter的缺省值为5 1`EkN0iZ  
//default value of nSplitter is 5 @)Sd3xw[  
this("","","",5); DUu~s,A  
} @?<1~/sfL  
>`.$Tyw  
VWE`wan<  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hc5iIJ]  
{ ^Jn=a9Q6Z  
sSiteURL= sURL; -D,kL  
sFilePath = sPath; 9TOqA4  
sFileName = sName; &GLe4zEh  
this.nSplitter = nSpiltter; u69s}yZ  
5JRj'G0I  
\"hP*DJ"  
} eWAgYe2  
23[XmBf  
5_Opx=  
public String getSSiteURL() m^ [VM&%  
{ M/a5o|>8  
return sSiteURL; BpZ17"\z  
} .2:S0=xt<  
S.A|(?x  
]k.'~ Syz  
public void setSSiteURL(String value) D<XRu4^;  
{ 2*@.hBi  
sSiteURL = value; AwO'%+Bv  
} 7`Bwo*Y  
[}bPkD  
G .k\N(l  
public String getSFilePath() DANndXQLH  
{ YO^iEI.  
return sFilePath; /QCyA%y  
} >^hy@m  
Di8;Tq  
[xsiSt?6  
public void setSFilePath(String value) 9J'3b <  
{ O/2Jz  
sFilePath = value; J?N9*ap)  
} ;Q} H'Wg,  
f.y~Sew  
5uufpvah  
public String getSFileName() 0ge^p O\Z  
{ Ffp<|2T2_  
return sFileName; Rk.GrLp  
} !4l\*L  
IB+)2`  
bP,_H  
public void setSFileName(String value) [r5k8TB1  
{ *=ymK*  
sFileName = value; z7P] g C$\  
} &,B91H*#  
#XlE_XD  
d~b#dcv$"  
public int getNSplitter() CAD:ifV  
{ *PVv=SU  
return nSplitter; SMdkD]{g  
} XUyoZl?  
t,yzqn  
eZWR)+aq  
public void setNSplitter(int nCount) 2dF:;k k  
{ WrGz`  
nSplitter = nCount; eL+L {Ac  
} HKdR?HM1  
} @GiR~bKZ  
PNbs7f  
.{|AHW&0<  
/* >xt*(j&}  
**Utility.java fii\&p7z  
*/ `(9B(&t^,  
package NetFox; :tA|g  
Uieg4Iro  
.ZxH#l _  
public class Utility { a;A&>Ei}  
*0^t;A+  
|UO1vA@  
public Utility() U "qO&;m  
{ H5N(MihT  
X&<#3n  
d.7Xvx0Yww  
} adJoT-8P6  
Lu~e^Ul   
//线程睡眠 +(3PY  e\  
public static void sleep(int nSecond) Ik#>6  
{ IP1|$b}sq  
try{ Kup-O u,  
Thread.sleep(nSecond); vR?L/G^.  
} ^/Hj^4~_U  
catch(Exception e) DOXRU5uP3  
{ g"3h#SMb  
e.printStackTrace (); ;D/'7f7.}  
} #oYX0wvl  
} Oh:SH|=]#  
RU `TzD  
//日志 K@{jY\AZNx  
public static void log(String sMsg) T T0O %  
{ rr4yJ;qpeP  
System.err.println(sMsg); XEZ6%Q_  
} tS2lex%  
?<  w +{  
@D"1}CW  
public static void log(int sMsg) nX Qz  
{ #%e`OA(b  
System.err.println(sMsg); /]xd[^  
} Yb =8\<;  
} UsQv!Cwu^  
RpLm'~N'  
yB. 6U56  
/* ==(M vu`  
**TestMethod.java l}AB):<Z  
*/ Gz*U?R-T  
package NetFox; <6apv(2a  
$i`YtV  
n_+Iw,a'm  
public class TestMethod { 3~S~)quwP  
0!zWXKX  
_6[NYv$"  
public TestMethod() C'$U1%: j  
{ ///xx/weblogic60b2_win.exe CRf^6k_;(  
try{ {M$8V~8D  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #\M<6n{  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~\_E%NR yA  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9(I4x]`  
fileFetch.start(); [gE2lfaEy  
} oy |@m|J  
catch(Exception e){e.printStackTrace ();} NSkI2>+P  
P6?Q;-\q0  
w])Sz*J  
} 2-6-kS)c  
&, )tD62s  
:H87x?e[  
public static void main(String[] args) :=8vy  
{ cP Y^Bf5)  
new TestMethod(); v ;A  
} f ;Dz(~ hw  
} XU54skN  
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