JavaBean



先看代碼：

package entity;

public class Student {
 private String username;
 private int age;

 public Student() {
  super();
 }

 public Student(String username, int age) {
  super();
  this.username = username;
  this.age = age;
 }
 
 public String getUsername() {
  return username;
 }

 public void setUsername(String username) {
  this.username = username;
 }

 
 public int getAge() {
  return age;
 }

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

}

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<jsp:useBean id="student" class="entity.Student"></jsp:useBean>
 
 <jsp:setProperty property="username" name="student" value="syy" />
 <jsp:setProperty property="age" name="student" value="23" />

 <jsp:getProperty property="username" name="student"/>
 <jsp:getProperty property="age" name="student"/>

總結：JavaBean需要注意的三個點

1)這個Java類必須具有一個無參的構造函數.

2)屬性必須私有化,用private修飾.

3)提供公開的getter和setter方法獲取屬性值或者設置屬性值.