Java 为什么结果没有显示出来

为什么我的输出不来

adder.java

package action;
public class adder {
    int num1,num2,result2;
    public String execute()
    {
        result2=num1+num2;
        return "success";
    }
    public int getNum1() {
        return num1;
    }
    public void setNum1(int num1) {
        this.num1 = num1;
    }
    public int getNum2() {
        return num2;
    }
    public void setNum2(int num2) {
        this.num2 = num2;
    }

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
  <display-name>letsgo</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <filter>
  <filter-name>f1</filter-name>
  <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
  </filter>
  <filter-mapping>
  <filter-name>f1</filter-name>
  <url-pattern>/*</url-pattern>
  </filter-mapping>
</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC 
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
    <struts>
    <package name="default" extends="struts-default">
    <action name="adder" class="action.adder" >
    <result name="success">/MyJsp.jsp</result>

    </action>
    </package>
    </struts>

莱斯哥
index.jsp
f1
org.apache.struts2.dispatcher.FilterDispatcher
f1
/*

index.jsp

<%@taglib uri="/struts-tags" prefix="s"%>
<s:form action="adder">
<s:textfield name="num1" label="firstnumber"/>
<s:textfield name="num2" label="secondnumber"/>
<s:submit value="add"/>
</s:form>

<%@taglib uri="/struts-tags" prefix="s"%>
<b>result is
<s:property value="result2"/>
</b>
<br/> 
<jsp:include page="index.jsp"/>

MyJsp.jsp

<%@taglib uri="/struts-tags" prefix="s"%>
<s:form action="adder">
<s:textfield name="num1" label="firstnumber"/>
<s:textfield name="num2" label="secondnumber"/>
<s:submit value="add"/>
</s:form>

<%@taglib uri="/struts-tags" prefix="s"%>
<b>result is
<s:property value="result2"/>
</b>
<br/> 
<jsp:include page="index.jsp"/>

结果是

struts.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
  <display-name>letsgo</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <filter>
  <filter-name>f1</filter-name>
  <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
  </filter>
  <filter-mapping>
  <filter-name>f1</filter-name>
  <url-pattern>/*</url-pattern>
  </filter-mapping>
</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC 
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
    <struts>
    <package name="default" extends="struts-default">
    <action name="adder" class="action.adder" >
    <result name="success">/MyJsp.jsp</result>

    </action>
    </package>
    </struts>

/MyJsp.jsp

---

输出为

结果为

，但不显示结果值

它无法绑定到您尝试用于Web服务器的任何端口。我猜是您忘记关闭一个实例，或者它正在挂起。

您缺少

result2

的Getter

您还应该声明变量

private

---

您还使用了旧的过滤器Dispatcher：如果您使用的是Struts2>2.1.3，请记住使用新过滤器进行更改，StrutsPrepareAndExecuteFilter

您检查了日志中的错误了吗？@jgitter严重：初始化端点java.net.BindException:严重：Catalina.start LifecycleException:该绑定异常的其余消息是什么？我不这么认为，因为当我将属性从result更改为num1时，它正在显示..肯定有一些关于代码的东西，然后你在评论中发布了一条非常旧的错误消息。清除日志，重试，然后发布结果错误。