如何使用useBean 並舉一個簡單的範例
1.使用jsp:useBean來存放javaBean讓程式看起來比較簡單

2.首先先定義一個java bean 叫UserData
有3個成員, firstName , lastName ,age
使用netBeans的生成工具快速產生get 和set的方法
宣告完變數後,在空白的地方按右鍵,選Insert Code... -->Getter and Setter...

UserData.java

  package bean;

public class UserData {
  private String firstName;
  private String lastName;
  private int age;

  public int getAge() {
    return age;
  }

  public void setAge(int age) {
    this.age = age;
  }

  public String getFirstName() {
    return firstName;
  }

  public void setFirstName(String firstName) {
    this.firstName = firstName;
  }

  public String getLastName() {
    return lastName;
  }

  public void setLastName(String lastName) {
    this.lastName = lastName;
  }
}

3.先寫輸入的畫面,會傳三個參數到SaveName.jsp

  <%@page contentType="text/html" pageEncoding="UTF-8"%>

    
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    
    
      <form method="post" action="SaveName.jsp">
          First name: <input type="text" name=firstName ><br>
          Last Name: <input type="text" name=lastName ><br>
          Age: <input type="text" name=age ><br>
        <input type="submit" name="submit" value="Save">
      </form>
    

4.用setProperty把參數接下來並只到一開始所寫的bean.UserData ,注意一定要給useBean 一個id

  <%@page contentType="text/html" pageEncoding="UTF-8"%>
<jsp:useBean id="user" class="bean.UserData" scope="session"/>
<jsp:setProperty name="user" property="*"/>

  
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>JSP Page</title>
  
  
  <A HREF="showPage.jsp">Continue</A>
  

5.最後再把剛才輸入的值秀出來

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<jsp:useBean id="user" class="bean.UserData" scope="session"/>

    
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    
    
        You entered<BR>
        First Name: <%= user.getFirstName() %><BR>
        Last Name: <%= user.getLastName() %><BR>
        Age: <%= user.getAge() %><BR>