javabean
-----------------------------------------------
package calculator;
public class SimpleCalculator
{
//sheng ming shu xing
private String first;//number 1
private String second;//number 2
private double result;//jie guo
private String operator;//fu hao
//fang fa
public void setFirst(String first)
{
this.first=first;
}
public void setSecond(String second)
{
this.second=second;
}
public void setOperator(String operator)
{
this.operator=operator;
}
public String getFirst()
{
return this.first;
}
public String getSecond()
{
return this.second;
}
public String getOperator()
{
return this.operator;
}
//huo de jie guo
public double getResult()
{
return this.result;
}
//pan duan cao zuo fu hao
public void calculate()
{
double one=Double.parseDouble(first);
double two=Double.parseDouble(second);
try
{
if(operator.equals("+"))result=one+two;
else if(operator.equals("-"))result=one-two;
else if(operator.equals("*"))result=one*two;
else if(operator.equals("/"))result=one/two;
}
catch(Exception e)
{
System.out.println(e);
}
}
}
-----------------------------------------------
package calculator;
public class SimpleCalculator
{
//sheng ming shu xing
private String first;//number 1
private String second;//number 2
private double result;//jie guo
private String operator;//fu hao
//fang fa
public void setFirst(String first)
{
this.first=first;
}
public void setSecond(String second)
{
this.second=second;
}
public void setOperator(String operator)
{
this.operator=operator;
}
public String getFirst()
{
return this.first;
}
public String getSecond()
{
return this.second;
}
public String getOperator()
{
return this.operator;
}
//huo de jie guo
public double getResult()
{
return this.result;
}
//pan duan cao zuo fu hao
public void calculate()
{
double one=Double.parseDouble(first);
double two=Double.parseDouble(second);
try
{
if(operator.equals("+"))result=one+two;
else if(operator.equals("-"))result=one-two;
else if(operator.equals("*"))result=one*two;
else if(operator.equals("/"))result=one/two;
}
catch(Exception e)
{
System.out.println(e);
}
}
}
-----------------------------------------------
<% @page contentType="text/html;charset=gb2312"language="java" import="java.sql.*"
errorPage="" %>
<jsp:useBean id="calculator" scope="request" class="calculator.SimpleCalculator">
<jsp:setProperty name="calculator" property="*"/>
</jsp:useBean>
<html>
<head>
<title>Doucument</title>
<meta http-equiv="Content-Type" content="text/html;charset=gb2312">
</head>
<body>
<hr>
计算结果：<%
try
{
calculator.calculate();
out.println(calculator.getFirst()+calculator.getOperator()+calculator.getSecond()
+"="+calculator.getResult());
}
catch(Exception e)
{
out.println(e.getMessage());
}
%>
</hr>
<form action="calculate.jsp" method="get">
<table width="75%" border="1" bordercolor="#003300">
<tr bgcolor="#999999">
<td>第一个数</td>
<td><input type="text" name="first"></td>
</tr>
<tr>
<td>操作符</td>
<td><select name="operator">
<option value="+">+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select></td>
</tr>
<tr>
<td>第二个数</td>
<td><input type="text" name="second"></td>
</tr>
<tr>
<td colspan="2" bgcolor="#cccccc"><input type="submit" value="start"></td>
</tr>
</table>
</form>
</body>
</html>
|
|
<%@ page
errorPage="" %>改成
<% @ page contentType="text/html;charset=gb2312"language="java" import="java.sql.*"
errorPage="" %>注意要有空格
org.apache.jasper.JasperException: Unable to compile class for JSPAn error occurred at line: 3 in the jsp file: /calculate.jspGenerated servlet error:
[javac] Compiling 1 source fileF:\Tomcat 5.0\work\Catalina\localhost\myapp\org\apache\jsp\calculate_jsp.java:43: package calculator does not exist
calculator.SimpleCalculator calculator = null;
^An error occurred at line: 3 in the jsp file: /calculate.jspGenerated servlet error:
F:\Tomcat 5.0\work\Catalina\localhost\myapp\org\apache\jsp\calculate_jsp.java:45: package calculator does not exist
calculator = (calculator.SimpleCalculator) pageContext.getAttribute("calculator", PageContext.REQUEST_SCOPE);
^An error occurred at line: 3 in the jsp file: /calculate.jspGenerated servlet error:
F:\Tomcat 5.0\work\Catalina\localhost\myapp\org\apache\jsp\calculate_jsp.java:47: package calculator does not exist
calculator = new calculator.SimpleCalculator();
^
The system is out of resources.
Consult the following stack trace for details.
java.lang.OutOfMemoryError
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:127)
org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:351)
org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:415)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:458)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:439)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:552)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:291)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:301)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:248)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)