何为JavaBean
JavaBean 是特殊的 Java 类,使用 Java 语言书写,并且遵守 JavaBean API 规范。 接下来给出的是 JavaBean 与其它 Java 类相比而言独一无二的特征:
- 提供一个默认的无参构造函数。
- 需要被序列化并且实现了 Serializable 接口。
- 可能有一系列可读写属性。
- 可能有一系列的 getter 或 setter 方法。 大致形状如下:
public class People {
private int id;
private String name;
private int age;
private String address;
public People() {
}
public People(int id, String name, int age, String address) {
this.id = id;
this.name = name;
this.age = age;
this.address = address;
}
@Override
public String toString() {
return "People{" +
"id=" + id +
", name='" + name + '\'' +
", age=" + age +
", address='" + address + '\'' +
'}';
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
在JSP中如何使用
形状如下:
<jsp:useBean id="people" class="bean.People" scope="page"></jsp:useBean>
<jsp:setProperty name="people" property="id" value="1"></jsp:setProperty>
<jsp:setProperty name="people" property="age" value="13"></jsp:setProperty>
<jsp:setProperty name="people" property="name" value="kittyguy"></jsp:setProperty>
<jsp:setProperty name="people" property="address" value="北京"></jsp:setProperty>
<jsp:getProperty name="people" property="id"/><br>
<jsp:getProperty name="people" property="age"/><br>
<jsp:getProperty name="people" property="name"/><br>
<jsp:getProperty name="people" property="address"/><br>
期间遇到的错误
===================================================
- 无法为JSP编译类
- People cannot be resolved to a type(无法解析该类)
解决该问题的依据
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总结
- 尽量不要在默认包下创建类,会出问题