The JavaBean of Web beginners

JavaBean

class 1.javaBean: Special java classes for encapsulation and reuse purposes. Often JavaBean is used in conjunction with Jsp to form JavaBean technology.

(1) Specifications for JavaBean:

JavaBean is a public class .

has a non-parametric constructor (that is, the default constructor method)

Provides the setxxx () method and the getXxx () method

(2) Code example :

 PackageCom.chapter07.javabean; Public classPerson {PrivateString name; Private intAge ; PrivateString address; /*Public Person () {name= "HHHH";        age=12;    Address= "121232"; }*/         PublicString GetName () {returnname; }     Public voidsetName (String name) { This. Name =name; }     Public intGetage () {returnAge ; }     Public voidSetage (intAge ) {         This. Age =Age ; }     PublicString getaddress () {returnaddress; }     Public voidsetaddress (String address) { This. Address =address; }}

2. JSP action elements :

(1) <jsp:usebean>: established scope to find a name-setting JavaBean object that exists as a direct return

Returns a reference to the JavaBean object that does not exist and instantiates a new JavaBean object.

Example:

(2) <jsp:setproperty>: Assigning values to a JavaBean property, and <jsp:useBean> Action with. Can be used between the <jsp:useBean> element start tag and the terminating tag, where its properties are initialized when the JavaBean object is instantiated.

Example:

(3) <jsp:getProperty> used to get a property value from a JavaBean , it is converted to a value of type String.

Example :

The JavaBean of Web beginners