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http断点续传简单实现(java)

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/* qJT0Y/l:(  
**SiteFileFetch.java 7/X"z=Q^|  
*/ 7yiJ1K<bIt  
package NetFox; I]J*BD#n.  
import java.io.*; ;ggy5?>Qu  
import java.net.*; vV`|!5x  
g.#+z'l  
r<L#q)]  
public class SiteFileFetch extends Thread { ;? uC=o>Z{  
gw3NS8 A+  
qG >DTKIU  
SiteInfoBean siteInfoBean = null; //文件信息Bean $ A-b vL  
long[] nStartPos; //开始位置 U06o ;s(  
long[] nEndPos; //结束位置 XqR{.jF.  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ._p""'Sa  
long nFileLength; //文件长度 /k7wwZiY@  
boolean bFirst = true; //是否第一次取文件  ?9u4a_x  
boolean bStop = false; //停止标志 VKLU0*2R  
File tmpFile; //文件下载的临时信息 }Pg' vJW  
DataOutputStream output; //输出到文件的输出流 h <[+HsI  
#Y,A[Y5jX  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) A@$fb}CF  
public SiteFileFetch(SiteInfoBean bean) throws IOException 0B0G2t&hr  
{ %N~C vN@T  
siteInfoBean = bean; DB&SOe  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); iM64,wnA  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); B$`lY DqaG  
if(tmpFile.exists ()) j=.g :&r)  
{ It 2UfW  
bFirst = false; #cEq_[yI  
read_nPos();  ~B@ }R  
} x|apQ6  
else S[@6Lp3q_  
{ .9\Cy4_qSd  
nStartPos = new long[bean.getNSplitter()]; &?$\Y,{  
nEndPos = new long[bean.getNSplitter()]; ~440# kj<  
} &9ki O  
REx[`x,GUh  
YbvX$/zGu  
TSyzdnMvz  
} ofEqvoi@  
tmxPO e  
7L{li-crI  
public void run() |z7dRDU}]  
{ c57bf  
//获得文件长度 A. Nz_!  
//分割文件 E2yz=7sv5  
//实例FileSplitterFetch 6IF|3@yD  
//启动FileSplitterFetch线程 x9*ys;~w  
//等待子线程返回 [>uwk``_  
try{ $T)d!$  
if(bFirst) ~ iT{8  
{ 3Bd4 C]E  
nFileLength = getFileSize(); 3GWrn ,f  
if(nFileLength == -1) :Ba-u  
{ /2:Q6J  
System.err.println("File Length is not known!"); cJ4S!  
} j[T%'%  
else if(nFileLength == -2) I;iR(Hf)?q  
{ .5k^f5a  
System.err.println("File is not access!"); 'Fzuc^G(d  
} }@4| 7  
else v j@V !j?  
{ w2<*$~C]  
for(int i=0;i<nStartPos.length;i++) XkoWL  
{ zuj;T,R;  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); <d<RK@2-  
} }-@I#9  
for(int i=0;i<nEndPos.length-1;i++) - coy@S=.'  
{ :dbV2'vIQ  
nEndPos = nStartPos[i+1]; `QAh5r"  
} D1~^\)*  
nEndPos[nEndPos.length-1] = nFileLength; )ldUayJ  
} {G]`1Q1DR  
} 'v`~(9'Rcj  
l2M/ ,@G  
kBUufV~  
//启动子线程 S&`O\!NF  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9/Q S0  
for(int i=0;i<nStartPos.length;i++) <e^6.!;W  
{ :EaiM J_=  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X!?wL 0n  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =1&}t%<X  
nStartPos,nEndPos,i); :'b%5/ ^q  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m>+A*M8  
fileSplitterFetch.start(); i!ds{`d  
} v,@E}F~-f1  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3# :EK M~!  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zZw@c?  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Hm<M@M$aG  
nEndPos = " + nFileLength); xP{m9_Qj  
// fileSplitterFetch[nPos.length-1].start(); PH{ c,  
[j1^$n 8V  
's/27=o  
//等待子线程结束 olslzXn7o  
//int count = 0; aq$62>[  
//是否结束while循环 6#/LyzZq|  
boolean breakWhile = false; .M`LUb"!  
)SC`6(GW  
q 8tP29  
while(!bStop) "&s9cO.H  
{ Ed8U;U b  
write_nPos(); W=!F8g|Qz  
Utility.sleep(500); sL;z"N@PK  
breakWhile = true; eF*TLI<[^I  
KX$qM g1j  
aslNlH6  
for(int i=0;i<nStartPos.length;i++) y`T--v3mI  
{ 6Eij>{v  
if(!fileSplitterFetch.bDownOver) .)?2)Fl  
{ H{&a)!Ms  
breakWhile = false; ;N9n'Sq4  
break; lsN /$ M|}  
} @)S sKk|  
} Cw@k.{*7,  
if(breakWhile) hG< a  
break; `mh-pBVD1  
?T$*5d  
~k"eE V p  
//count++; wGZ>iLe:  
//if(count>4) :4Id7Ce  
// siteStop(); ?nj"Ptzs  
} Mt]=v}z  
M^!C?(Hx^x  
A?^A*e  
System.err.println("文件下载结束!"); u)N2  
} ski1f  
catch(Exception e){e.printStackTrace ();} /7!_un9  
} g!~-^_F  
58a)&s[+  
KY;uO 8Te  
//获得文件长度 Po2_ 0uX  
public long getFileSize() Ncs4<"{$  
{ '2Mjz6mBDA  
int nFileLength = -1; {PP ^Rb)  
try{ tIc0S!H#  
URL url = new URL(siteInfoBean.getSSiteURL()); 7TMDZ*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P':]A{<Z  
httpConnection.setRequestProperty("User-Agent","NetFox"); %Q>~7P  
/ynKKJx<Y  
%B*<BgJ;4F  
int responseCode=httpConnection.getResponseCode(); EU&6 Tg  
if(responseCode>=400) @ U7#, G  
{ (mOqv9pn  
processErrorCode(responseCode); rH [+/&w5  
return -2; //-2 represent access is error T<9dW?'|  
} u(TgWp5WF  
ly[\mGr  
mfp`Iy"}+  
String sHeader; P|!/mu]  
75^)Ni  
F|h ,a;2  
for(int i=1;;i++) 3.GdKP.%  
{ @[[C s*-  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ouu-wQ|(mM  
//Utility.log(in.readLine()); cN[ q)ts  
sHeader=httpConnection.getHeaderFieldKey(i); 6cgpg+-a  
if(sHeader!=null) jN5} 2 p*  
{ f0HV*%8  
if(sHeader.equals("Content-Length")) ^bY^x+d  
{ inq4CGY  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hhh: rmEZl  
break; \M3NasZ  
} )U/@J+{{  
} -?2&5YB  
else US*<I2ZLh  
break; f6aT[Nw<  
} 1z $}*`  
} EFT02#F_f  
catch(IOException e){e.printStackTrace ();} jmZ|b6  
catch(Exception e){e.printStackTrace ();} #4|i@0n}D  
O. .@<.  
,& pF:ql F  
Utility.log(nFileLength); 3gfV0C\  
1_dMe%53  
h#6 jUQ  
return nFileLength; HnKF#<  
} V+"*A  
t"Vr;0!{  
uq#h\p|  
//保存下载信息(文件指针位置) \Im \*A   
private void write_nPos() ^w.(*;/  
{ k0Vo  
try{ 59%f|.Z)  
output = new DataOutputStream(new FileOutputStream(tmpFile)); zdpLAr  
output.writeInt(nStartPos.length); T\b";+!W  
for(int i=0;i<nStartPos.length;i++) 4- ?`#  
{ JNA}EY^2I.  
// output.writeLong(nPos); J1v0 \  
output.writeLong(fileSplitterFetch.nStartPos); $/U^/2)  
output.writeLong(fileSplitterFetch.nEndPos); RWm Q]  
} `sp'Cl!  
output.close(); tRrY)eElS  
} jP7+s.j>  
catch(IOException e){e.printStackTrace ();} Hh'14n&W  
catch(Exception e){e.printStackTrace ();} $d"f/bRWy  
} 4`'BaUU(  
xYkgNXGs5  
owS@dbO  
//读取保存的下载信息(文件指针位置) ^zluO   
private void read_nPos() Q!A3hr$IF  
{ x2IU PM  
try{ fylA 0{  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JV6U0$g_S  
int nCount = input.readInt(); CR|&VxA  
nStartPos = new long[nCount]; -L'`d  
nEndPos = new long[nCount]; )GT?Wd  
for(int i=0;i<nStartPos.length;i++) a.*j8T  
{ hZ /  
nStartPos = input.readLong(); <cS7L0h  
nEndPos = input.readLong(); !Pjg&19  
} Hn]n]wsLy  
input.close(); 2BU)qv-  
} 1NHoIX  
catch(IOException e){e.printStackTrace ();} aD3F!Sn  
catch(Exception e){e.printStackTrace ();}  F3r  
} D"XQ!1B%  
nm|m1Z+U  
`m0Uj9)#  
private void processErrorCode(int nErrorCode) bqwW9D(  
{ u|*| RuY  
System.err.println("Error Code : " + nErrorCode); ydFhw}1>  
} dcTM02kEh  
[^BUhm3a  
Z.OrHg1  
//停止文件下载 U:p"IY#%  
public void siteStop() yt#;3  
{ xgw)`>p,W  
bStop = true; 5z mHb  
for(int i=0;i<nStartPos.length;i++) ?g#t3j>zoF  
fileSplitterFetch.splitterStop(); j I@$h_n  
8!`.%)- 4  
t }C ^E  
} F?AfB[PM  
} yl+)I  
//负责部分文件的抓取 ITY!=>S-  
**FileSplitterFetch.java 4bjp*1*]  
*/ J9t?]9.,:  
package NetFox; yacGJz^f=  
IMw)X0z  
#$rT 4N c;  
import java.io.*; i1\ /\^  
import java.net.*; f<:SdtG5  
)$N{(Cke2T  
V>j`  
public class FileSplitterFetch extends Thread { s31_3?Vdf,  
hg/&[/eodm  
n\al}KG  
String sURL; //File URL ]p.f*]  
long nStartPos; //File Snippet Start Position RKb3=} *C  
long nEndPos; //File Snippet End Position y:zT1I@>  
int nThreadID; //Thread's ID 4$w-A-\ t  
boolean bDownOver = false; //Downing is over BQ)43Rr>  
boolean bStop = false; //Stop identical w/D m  
FileAccessI fileAccessI = null; //File Access interface w3UJw  
84\o7@$#  
6]49kHgMhe  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fB}5,22  
{ =zGz|YI*?  
this.sURL = sURL; uKzz/Y{  
this.nStartPos = nStart; Z"KuS  
this.nEndPos = nEnd; *fX)=?h56  
nThreadID = id; +ANIm^@  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Zpd>' ${4  
} A0sW 9P6F  
V]cY+4Y  
`g1~ya(MC  
public void run() ")buDU6_  
{ u`nn{C4D"  
while(nStartPos < nEndPos && !bStop) 'J2P3t  
{ -^"?a]B  
lY?d*qED  
5-po>1g'  
try{ FeRuZww._J  
URL url = new URL(sURL); G\AQql(f4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ->{WO+6(  
httpConnection.setRequestProperty("User-Agent","NetFox"); CU&,Kq@  
String sProperty = "bytes="+nStartPos+"-"; x"T^>Q  
httpConnection.setRequestProperty("RANGE",sProperty); O:R{4Q*5  
Utility.log(sProperty); Ik)Q0_<a  
py4_hj\v  
|{"7/~*[  
InputStream input = httpConnection.getInputStream(); WR1,J0UU6  
//logResponseHead(httpConnection); }PuO$ L  
#<3\}*/  
s``L?9  
byte[] b = new byte[1024]; IGQ8-#=  
int nRead; EHjhe z  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @>ZjeDG>  
{ g"f^YEQ_  
nStartPos += fileAccessI.write(b,0,nRead); ,"ZlY}!Gn  
//if(nThreadID == 1) ajr8tp'  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x{5*%}lX8  
} ^Y |s^N  
Rw% KEUDm  
r2w7lf66!  
Utility.log("Thread " + nThreadID + " is over!"); nVD YAg'  
bDownOver = true; I78pul8!  
//nPos = fileAccessI.write (b,0,nRead); t]XJ q  
} oc Uu  
catch(Exception e){e.printStackTrace ();} 1jVcL)szU  
} Op~+yMef  
} iDJ2dM}v  
&rKhB-18)  
wl9icrR>  
//打印回应的头信息 6 [E"  
public void logResponseHead(HttpURLConnection con) O:)@J b2  
{ :f:C*mYvu  
for(int i=1;;i++) hI 0l2OE  
{ #u^d3 $Nj  
String header=con.getHeaderFieldKey(i); zZ-*/THB@R  
if(header!=null) ^lj>v}4fkW  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4G ?k31,k  
Utility.log(header+" : "+con.getHeaderField(header)); (z{xd  
else f0+  
break; 9:s!#FYFM  
} jL&F7itP  
} AaVlNjB  
uWE@7e4'I  
zT8K})#  
public void splitterStop() ML-g"wv  
{ hrK^oa_[W  
bStop = true; `N+ P ,  
} v3Kqs:"\  
]LjW,b"  
*v&RGY[>  
} #q%/~-Uk  
he@swE&  
e6Y0G,K  
/* wvD|c%   
**FileAccess.java 4j5plm=  
*//文件访问(定位,写) w'C(? ?mH  
package NetFox; `KN{0<Ne  
import java.io.*; LJ?7W,?  
dL>ZL1.$  
Wp $\>  
public class FileAccessI implements Serializable{ %-D2I  
&>SE9w/ ?o  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8}2 `^<U  
RandomAccessFile oSavedFile; oVdmgmT.Y  
long nPos; ZC"p^~U_e[  
uP.3(n[&  
JXrMtSp\  
public FileAccessI() throws IOException WD<M U ]  
{ '0+-Hit?  
this("",0); zKo,B/Ke4  
} q-'zZ#  
HzV3O-Qz]  
:7gIm|2"]  
public FileAccessI(String sName,long nPos) throws IOException gU:jx  
{ }QK-@T@4<  
oSavedFile = new RandomAccessFile(sName,"rw"); 9#+X?|p+0  
this.nPos = nPos; h1xYQF_`Z  
oSavedFile.seek(nPos); "bqB@)  
} ]'Bz%[C)  
umY4tNe]$  
+u7mw<A 8  
public synchronized int write(byte[] b,int nStart,int nLen) k# /_Zd  
{ czafBO6  
int n = -1; Lq:Z='Kc  
try{ FKPI{l  
oSavedFile.write(b,nStart,nLen); (c;$^xZK  
n = nLen; HQ"D>hsuU  
} :EZTJu  
catch(IOException e) 'j|;M  
{ AyddkjX  
e.printStackTrace (); 9!tRM-  
} v q|W&  
Tw$lakw  
\%UA6uj  
return n; 9i n&\  
} 8@ b83  
a4?:suX$  
UPH:$Fk&  
} *g7dB2{  
HA| YLj?|g  
uCx\Bt"VI  
/* dLLF#N  
**SiteInfoBean.java -Y D6  
*/ )]'?yS"  
package NetFox; p tMysYT'  
WL<Cj_N_{H  
{A{=RPL  
public class SiteInfoBean { J?HYN%  
Eg>MG87  
F9N)UW:w  
private String sSiteURL; //Site's URL YoJN.],gf  
private String sFilePath; //Saved File's Path aB.`'d)V  
private String sFileName; //Saved File's Name ~b*f2UVs  
private int nSplitter; //Count of Splited Downloading File ~u3E+w  
g9g^zd,  
@wb V@  
public SiteInfoBean() u9J;OsnHK  
{//nSplitter的缺省值为5 C,.$g>)MZK  
//default value of nSplitter is 5 :Fm)<VN"  
this("","","",5); p "u5wJ_  
} dx?4)lb  
i!9yN: m0  
L"9,K8  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zxY  
{ vn7<>k> dx  
sSiteURL= sURL; >zVj+  
sFilePath = sPath; 4 QD.'+ L  
sFileName = sName; UT%^!@u  
this.nSplitter = nSpiltter; #)z_TM07P  
5 ^+> *z  
YQLp#  
} 4gzrxV  
x xWnB  
?"\X46Gz;  
public String getSSiteURL() s${ew.eW  
{ pbt/i+!  
return sSiteURL; 6x7pqH M  
} f 0D9Mp  
F<VoPqHq  
r$<[`L+6  
public void setSSiteURL(String value)  $ac VJI?  
{ eKsc ["  
sSiteURL = value; ?VmE bl  
} |hk?'WGc`0  
g)nsP  
i{vM NI{  
public String getSFilePath() v!JQ;OX  
{ B_$hi=?TTd  
return sFilePath; [9Q}e;T  
} \4zb9CxOZ  
3=SIIMp7=  
nO.RB#I$F  
public void setSFilePath(String value) gTa6%GM>  
{ !Nua  
sFilePath = value; {@ ygq-TZ  
} p;$Vw6W=  
[<CIh46S.  
KsZd.Rf=@  
public String getSFileName() lC):$W  
{ KG=h!]Meq  
return sFileName; '[V}]Z>-  
} m_ >+$uL  
Kw_> X&GcJ  
qD0sD2 x  
public void setSFileName(String value) WCJ$S\#  
{ av~dH=&=  
sFileName = value; S&N[@G  
} FyY<Vx'yQ  
x=]PE}<E  
`IN/1=]5  
public int getNSplitter() Qv4g#jX{  
{ oS.fy31p  
return nSplitter; cG{>[Lf  
} " b?1Yc-  
w&VMb&<  
Teo&V  
public void setNSplitter(int nCount) `q":i>FP2  
{ NWx.l8G  
nSplitter = nCount; vOMmsU F  
} A|Z'\D0  
} ! 3&_#VO  
TX/Ng+v S  
fZ8at  
/* Y367Jr@^N  
**Utility.java [(Jj@HlP6T  
*/ c:>&iB-Yu  
package NetFox; >d1gVBhk  
hqr V {c  
DSb/+8KT  
public class Utility { n\CQ-*;l  
[,_4#Zz  
--X1oC52A  
public Utility() dG {D2~#  
{ Dl/Jlsd@  
b d!|/Lk  
"j(?fVx  
} D`|.%  
_@-D/g  
//线程睡眠 YSQB*FBz  
public static void sleep(int nSecond) iobL6SUZ  
{ I)9un|+,y  
try{ +aa( YGL  
Thread.sleep(nSecond); "'M>%m u  
} io8c[#"uU  
catch(Exception e) 1#o>< ?  
{ 1a|Z!Vzi  
e.printStackTrace (); XnBpL6"T`  
} 1K<4Kz~  
} <X5'uve  
}1N $4@  
//日志 wTT_jyH)  
public static void log(String sMsg) HW0EPJ  
{ kB`t_`7f  
System.err.println(sMsg); ,VtrQb)Yf  
} u2p5* gzZ  
=v (MdjwFl  
!kzC1U  
public static void log(int sMsg) &PfCY{_  
{ OIT9.c0h  
System.err.println(sMsg); $m$tfa-  
} oN0p$/La  
} fa~u<m   
{|{}]B  
b7X-mkF  
/* M!KHBr  
**TestMethod.java y-Xd~<*Ia  
*/ *Ey5F/N}$H  
package NetFox; hJ)>BeH0  
#1>DV@^F  
) ?AlQA  
public class TestMethod { BseK?`]U"  
uyd y[n\  
vXdz?  
public TestMethod() CA0SH{PdW&  
{ ///xx/weblogic60b2_win.exe XET'XJWF%  
try{ ;B8 #Nf  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); O{0TS^  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "K.XoG4|  
SiteFileFetch fileFetch = new SiteFileFetch(bean); }Pu|%\  
fileFetch.start(); a!`b`r -4  
} H|E{n/g  
catch(Exception e){e.printStackTrace ();} t>W^^'=E  
i\4Qv"%  
994   
} w&A &BE^O/  
! OM P]  
Rnl 4  
public static void main(String[] args) OokBi 02b  
{ h)O<bI8  
new TestMethod(); s_`PPl_D$K  
} @B<B#  
} #g ;][  
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