3.6.2 setProperty和getProperty
setProperty动作可对一个Java对象的属性设置属性值，而getProperty动作则会输出Java对象的一个属性的属性值。
实例
Person类:
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| package app03a;
public class Person
{
private String id;
private String firstName;
private String lastName;
public String getId()
{
return id;
}
public void setId(String id)
{
this.id = id;
}
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;
}
}
|
getSetPropertyTest.jsp:
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| <%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<title>getProperty and setProperty</title>
</head>
<body>
<%-- 创建一个app03a.Person类的对象,并把它保存在脚本变量employee中 --%>
<jsp:useBean id="employee" class="app03a.Person" />
<%-- 设置id为employee这个脚本变量所对应的对象的firstName成员变量的值为Blue --%>
<jsp:setProperty name="employee" property="firstName" value="Blue" />
First Name:
<%-- 取出id为employee这个脚本变量所对应的对象的firstName成员变量的值 --%>
<jsp:getProperty name="employee" property="firstName" />
</body>
</html>
|
访问这个JSP,显示效果如下:
![这里有一张图片]()
打开JSP页面转换成的getSetPropertyTest_jsp.java这个Servlet中的_jspService方法.可以看到上面的JSP页面被转换成如下代码:
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| out.write("<!DOCTYPE html>\r\n");
out.write("<html>\r\n");
out.write("<head>\r\n");
out.write("<title>getProperty and setProperty</title>\r\n");
out.write("</head>\r\n");
out.write("<body>\r\n");
out.write("\r\n");
out.write("\t");
app03a.Person employee = null;
employee = (app03a.Person) _jspx_page_context.getAttribute(
"employee", javax.servlet.jsp.PageContext.PAGE_SCOPE);
if (employee == null){
employee = new app03a.Person();
_jspx_page_context.setAttribute(
"employee", employee, javax.servlet.jsp.PageContext.PAGE_SCOPE);
}
out.write('\r');
out.write('\n');
out.write(' ');
out.write('\r');
out.write('\n');
out.write(' ');
org.apache.jasper.runtime.JspRuntimeLibrary.introspecthelper(
_jspx_page_context.findAttribute("employee"), "firstName", "Blue", null, null, false);
out.write("\r\n");
out.write("\tFirst Name:\r\n");
out.write("\t");
out.write('\r');
out.write('\n');
out.write(' ');
out.write(org.apache.jasper.runtime.JspRuntimeLibrary.toString(
(((app03a.Person)_jspx_page_context.findAttribute("employee")).getFirstName()))
);
out.write("\r\n");
out.write("</body>\r\n");
out.write("</html>");
|
