做了个(文本)计数器
感觉操作数据库不是很快,于是作了个文本计数器,servlet的,其实很多代码网上都有.再win2000s+tomcat5.0下测试通过.代码如下:
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
public class counter extends HttpServlet {
private static final String CONTENT_TYPE = "text/html; charset=GBK";
String countNums[] =null;
String countNum[]=null;
String counts[]=null;
String temper=null;
int count=0;
int counters=0;
String path="e:\\counter.txt";//可以自己定义文件的路径,counter.txt里面设置初始值(int型!)
int numLen =0;
//Initialize global variables
public void init() throws ServletException {
}
//Process the HTTP Get request
public void doGet(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter();
counts=this.counting();
for(int i=0;i<counts.length;i++)//一般说来访问量不会超过这个的最大值吧
{
out.print(counts[i]);
}
}
//Clean up resources
public void destroy() {
}
public void doPost(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException{
doGet(request,response);
}
public String[] counting() throws IOException{//逐个取出数字
try {
FileReader fr = new FileReader(path);
BufferedReader br=new BufferedReader(fr);
String Line=br.readLine();
if (Line!=null)
{
temper=Line;
numLen =Line.length();
countNums=new String[numLen];
countNum=new String[numLen];
for(int l = 0; l <= numLen - 1; l++)
{
countNum[l] =Line.substring(l++, l);
l--;
countNums[l] = "<img src='../../counter/"+countNum[l] + ".jpg' width='20'
height='29'>";//将包含图片的counter文件夹放在webapps下,图片格式为jpg,文件名为0-9;
}
br.close();
fr.close();
this.addNum();
}
}
catch(Exception exception)
{
System.out.println("Init Error:" + exception);
}
return countNums;
}
public void addNum()
{
try {
File txt= new File(path);
PrintWriter out = new PrintWriter(new FileWriter(txt));
count=Integer.parseInt(temper.toString());
counters=count+1;//计数器增加一
out.print(counters);//写入文件counter.txt
out.close();
}
catch (IOException e) {
System.out.print(e.toString());
}
}
}