请大家看看我的程序和出现的问题,问题很明显,就是不知道如何解决

wootea007 2003-10-15 07:13:27
程序如下,用到了Beans三角形beans
Triangle.java:
public class Triangle
{ double sideA,sideB,sideC;
double area;
boolean triangle;
public void setSideA(double a)
{sideA=a;
}
public double getSideA()
{return sideA;
}
public void setSideB(double b)
{sideB=b;
}
public double getSideB()
{return sideB;
}
public void setSideC(double c)
{sideC=c;
}
public double getSideC()
{return sideC;
}
public double getArea()
{ double p=(sideA+sideB+sideC)/2.0;
area=Math.sqrt(p*(p-sideA)*(p-sideB)*(p-sideC));
return area;
}
public boolean isTriangle()
{ if(sideA<sideB+sideC&&sideB<sideA+sideC&&sideC<sideA+sideB)
triangle=true;
else
triangle=false;
return triangle;
}

}

使用三角形beans的JSP页面
triangle.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<%@ page import="Triangle"%>
<HTML>
<BODY ><Font size=1>
<FORM action="" Method="post" >
<P>输入三角形的边A:
<Input type=text name="sideA" value=0>
<P>输入三角形的边B:
<Input type=text name="sideB" value=0>
<P>输入三角形的边C:
<Input type=text name="sideC" value=0>
<Input type=submit value="提交">
<P>你给出三角形的三边是:
<jsp:useBean id="triangle" class="Triangle" scope="page" >
</jsp:useBean>
<jsp:setProperty name= "triangle" property="*" />
<BR>边A是:
<jsp:getProperty name= "triangle" property="sideA" />
<BR>边B是:
<jsp:getProperty name= "triangle" property="sideB" />
<BR>边C是:
<jsp:getProperty name= "triangle" property="sideC" />
<P>这三个边能构成一个三角形吗?
<jsp:getProperty name= "triangle" property="triangle" />
<P>面积是:
<jsp:getProperty name= "triangle" property="area" />
</FONT>
</BODY>
</HTML>

Counter.java:
public class Counter
{ long count=0;
public synchronized long getCount()
{count++;
return count;
}
}

生成的class文件放在D:\Tomcat\tomcat-4.1.27\jakarta-tomcat-4.1.27\examples\webapps\Web-inf\classes目录下
jsp和java文件放在D:\Tomcat\tomcat-4.1.27\jakarta-tomcat-4.1.27\examples目录下

结果调试的时候出现了如下问题:

org.apache.jasper.JasperException: Unable to compile class for JSP

An error occurred at line: 13 in the jsp file: /triangle.jsp

Generated servlet error:
[javac] Compiling 1 source file

D:\tomcat-4.1.27\jakarta-tomcat-4.1.27\work\Standalone\localhost\examples\triangle_jsp.java:7: '.' expected
import Triangle;
^
D:\tomcat-4.1.27\jakarta-tomcat-4.1.27\work\Standalone\localhost\examples\triangle_jsp.java:56: cannot resolve symbol
symbol : class Triangle
location: class org.apache.jsp.triangle_jsp
Triangle triangle = null;
^



An error occurred at line: 13 in the jsp file: /triangle.jsp

Generated servlet error:
D:\tomcat-4.1.27\jakarta-tomcat-4.1.27\work\Standalone\localhost\examples\triangle_jsp.java:58: cannot resolve symbol
symbol : class Triangle
location: class org.apache.jsp.triangle_jsp
triangle = (Triangle) pageContext.getAttribute("triangle", PageContext.PAGE_SCOPE);
^



An error occurred at line: 13 in the jsp file: /triangle.jsp

Generated servlet error:
D:\tomcat-4.1.27\jakarta-tomcat-4.1.27\work\Standalone\localhost\examples\triangle_jsp.java:61: cannot resolve symbol
symbol : class Triangle
location: class org.apache.jsp.triangle_jsp
triangle = (Triangle) java.beans.Beans.instantiate(this.getClass().getClassLoader(), "Triangle");
^



An error occurred at line: 17 in the jsp file: /triangle.jsp

Generated servlet error:
D:\tomcat-4.1.27\jakarta-tomcat-4.1.27\work\Standalone\localhost\examples\triangle_jsp.java:75: cannot resolve symbol
symbol : class Triangle
location: class org.apache.jsp.triangle_jsp
out.print(JspRuntimeLibrary.toString((((Triangle)pageContext.findAttribute("triangle")).getSideA())));
^



An error occurred at line: 19 in the jsp file: /triangle.jsp

Generated servlet error:
D:\tomcat-4.1.27\jakarta-tomcat-4.1.27\work\Standalone\localhost\examples\triangle_jsp.java:78: cannot resolve symbol
symbol : class Triangle
location: class org.apache.jsp.triangle_jsp
out.print(JspRuntimeLibrary.toString((((Triangle)pageContext.findAttribute("triangle")).getSideB())));
^



An error occurred at line: 21 in the jsp file: /triangle.jsp

Generated servlet error:
D:\tomcat-4.1.27\jakarta-tomcat-4.1.27\work\Standalone\localhost\examples\triangle_jsp.java:81: cannot resolve symbol
symbol : class Triangle
location: class org.apache.jsp.triangle_jsp
out.print(JspRuntimeLibrary.toString((((Triangle)pageContext.findAttribute("triangle")).getSideC())));
^



An error occurred at line: 23 in the jsp file: /triangle.jsp

Generated servlet error:
D:\tomcat-4.1.27\jakarta-tomcat-4.1.27\work\Standalone\localhost\examples\triangle_jsp.java:84: cannot resolve symbol
symbol : class Triangle
location: class org.apache.jsp.triangle_jsp
out.print(JspRuntimeLibrary.toString((((Triangle)pageContext.findAttribute("triangle")).isTriangle())));
^



An error occurred at line: 25 in the jsp file: /triangle.jsp

Generated servlet error:
D:\tomcat-4.1.27\jakarta-tomcat-4.1.27\work\Standalone\localhost\examples\triangle_jsp.java:87: cannot resolve symbol
symbol : class Triangle
location: class org.apache.jsp.triangle_jsp
out.print(JspRuntimeLibrary.toString((((Triangle)pageContext.findAttribute("triangle")).getArea())));
^
9 errors


请大家帮帮我,看问题出在哪里,是不是对Beans的使用和设置不当???
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caominfengok 2003-10-15
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把你的JAVA代码放在一个包路径里看看,我发现有时候不同版本的TOMCAT会出现对于没有包路径的CLASS文件不认。
conning333 2003-10-15
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生成的class文件放在D:\Tomcat\tomcat-4.1.27\jakarta-tomcat-4.1.27\examples\webapps\Web-inf\classes目录下
jsp和java文件放在D:\Tomcat\tomcat-4.1.27\jakarta-tomcat-4.1.27\examples目录下
??????
这里有问题吧?》java文件不需要。不过也不影响。jsp不管你放在哪,都应该是和web-inf同级的目录!!而且你的错误也很明显,就是找不到类,使用tomcat最好是放在server下面的webapp下面,最好新建一个目录来访。
wootea007 2003-10-15
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奇怪的是,我的程序在同学的机器上试没事情,但是到了我的机器试就有问题了
truezerg 2003-10-15
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代码太多了。哈,等我有时候再看吧

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