freemarker处理空值
1、设计思路
（1）封装学生类和课程类
（2）新建学生课程页面ftl文件
（3）创建测试方法
2、封装课程类
Course.java：
/**
* @Title:Course.java
* @Package:com.you.freemarker.model
* @Description:课程封装类
* @author:Youhaidong(游海东)
* @date:2014-5-28 下午9:41:41
* @version V1.0
*/
package com.you.freemarker.model;
/**
* 类功能说明
* 类修改者 修改日期
* 修改说明
* <p>Title:Course.java</p>
* <p>Description:游海东个人开发</p>
* <p>Copyright:Copyright(c)2013</p>
* @author:游海东
* @date:2014-5-28 下午9:41:41
* @version V1.0
*/
public class Course
{
/**
* 课程名
*/
private String courseName;
/**
* @return the courseName
*/
public String getCourseName() {
return courseName;
}
/**
* @param courseName the courseName to set
*/
public void setCourseName(String courseName) {
this.courseName = courseName;
}
/**
* <p>Title:</p>
* <p>Description:有参构造函数</p>
* @param courseName
*/
public Course(String courseName) {
super();
this.courseName = courseName;
}
/**
* <p>Title:</p>
* <p>Description:无参构造函数</p>
*/
public Course() {
super();
}
}
3、封装学生类
Student.java：
/**
* @Title:Student.java
* @Package:com.you.freemarker.model
* @Description:学生类
* @author:Youhaidong(游海东)
* @date:2014-5-26 下午11:41:05
* @version V1.0
*/
package com.you.freemarker.model;
import java.io.Serializable;
import java.util.Date;
/**
* 类功能说明
* 类修改者 修改日期
* 修改说明
* <p>Title:Student.java</p>
* <p>Description:游海东个人开发</p>
* <p>Copyright:Copyright(c)2013</p>
* @author:游海东
* @date:2014-5-26 下午11:41:05
* @version V1.0
*/
public class Student implements Serializable
{
/**
* @Fields serialVersionUID:序列化
*/
private static final long serialVersionUID = 1L;
/**
* 学生姓名
*/
private String studentName;
/**
* 学生性别
*/
private String studentSex;
/**
* 学生年龄
*/
private int studentAge;
/**
* 学生生日
*/
private Date studentBirthday;
/**
* 学生地址
*/
private String studentAddr;
/**
* QQ
*/
private long studentQQ;
/**
* 课程
*/
private Course course;
/**
* @return the studentName
*/
public String getStudentName() {
return studentName;
}
/**
* @param studentName the studentName to set
*/
public void setStudentName(String studentName) {
this.studentName = studentName;
}
/**
* @return the studentSex
*/
public String getStudentSex() {
return studentSex;
}
/**
* @param studentSex the studentSex to set
*/
public void setStudentSex(String studentSex) {
this.studentSex = studentSex;
}
/**
* @return the studentAge
*/
public int getStudentAge() {
return studentAge;
}
/**
* @param studentAge the studentAge to set
*/
public void setStudentAge(int studentAge) {
this.studentAge = studentAge;
}
/**
* @return the studentBirthday
*/
public Date getStudentBirthday() {
return studentBirthday;
}
/**
* @param studentBirthday the studentBirthday to set
*/
public void setStudentBirthday(Date studentBirthday) {
this.studentBirthday = studentBirthday;
}
/**
* @return the studentAddr
*/
public String getStudentAddr() {
return studentAddr;
}
/**
* @param studentAddr the studentAddr to set
*/
public void setStudentAddr(String studentAddr) {
this.studentAddr = studentAddr;
}
/**
* @return the studentQQ
*/
public long getStudentQQ() {
return studentQQ;
}
/**
* @param studentQQ the studentQQ to set
*/
public void setStudentQQ(long studentQQ) {
this.studentQQ = studentQQ;
}
/**
* <p>Title:</p>
* <p>Description:无参构造函数</p>
*/
public Student() {
super();
}
/**
* <p>Title:</p>
* <p>Description:有参构造函数</p>
* @param studentName
* @param studentSex
* @param studentAge
* @param studentBirthday
* @param studentAddr
* @param studentQQ
*/
public Student(String studentName, String studentSex, int studentAge,
Date studentBirthday, String studentAddr, long studentQQ) {
super();
this.studentName = studentName;
this.studentSex = studentSex;
this.studentAge = studentAge;
this.studentBirthday = studentBirthday;
this.studentAddr = studentAddr;
this.studentQQ = studentQQ;
}
/**
* @return the course
*/
public Course getCourse() {
return course;
}
/**
* @param course the course to set
*/
public void setCourse(Course course) {
this.course = course;
}
}
/**
* @Title:Student.java
* @Package:com.you.freemarker.model
* @Description:学生类
* @author:Youhaidong(游海东)
* @date:2014-5-26 下午11:41:05
* @version V1.0
*/
package com.you.freemarker.model;
import java.io.Serializable;
import java.util.Date;
/**
* 类功能说明
* 类修改者 修改日期
* 修改说明
* <p>Title:Student.java</p>
* <p>Description:游海东个人开发</p>
* <p>Copyright:Copyright(c)2013</p>
* @author:游海东
* @date:2014-5-26 下午11:41:05
* @version V1.0
*/
public class Student implements Serializable
{
/**
* @Fields serialVersionUID:序列化
*/
private static final long serialVersionUID = 1L;
/**
* 学生姓名
*/
private String studentName;
/**
* 学生性别
*/
private String studentSex;
/**
* 学生年龄
*/
private int studentAge;
/**
* 学生生日
*/
private Date studentBirthday;
/**
* 学生地址
*/
private String studentAddr;
/**
* QQ
*/
private long studentQQ;
/**
* 课程
*/
private Course course;
/**
* @return the studentName
*/
public String getStudentName() {
return studentName;
}
/**
* @param studentName the studentName to set
*/
public void setStudentName(String studentName) {
this.studentName = studentName;
}
/**
* @return the studentSex
*/
public String getStudentSex() {
return studentSex;
}
/**
* @param studentSex the studentSex to set
*/
public void setStudentSex(String studentSex) {
this.studentSex = studentSex;
}
/**
* @return the studentAge
*/
public int getStudentAge() {
return studentAge;
}
/**
* @param studentAge the studentAge to set
*/
public void setStudentAge(int studentAge) {
this.studentAge = studentAge;
}
/**
* @return the studentBirthday
*/
public Date getStudentBirthday() {
return studentBirthday;
}
/**
* @param studentBirthday the studentBirthday to set
*/
public void setStudentBirthday(Date studentBirthday) {
this.studentBirthday = studentBirthday;
}
/**
* @return the studentAddr
*/
public String getStudentAddr() {
return studentAddr;
}
/**
* @param studentAddr the studentAddr to set
*/
public void setStudentAddr(String studentAddr) {
this.studentAddr = studentAddr;
}
/**
* @return the studentQQ
*/
public long getStudentQQ() {
return studentQQ;
}
/**
* @param studentQQ the studentQQ to set
*/
public void setStudentQQ(long studentQQ) {
this.studentQQ = studentQQ;
}
/**
* <p>Title:</p>
* <p>Description:无参构造函数</p>
*/
public Student() {
super();
}
/**
* <p>Title:</p>
* <p>Description:有参构造函数</p>
* @param studentName
* @param studentSex
* @param studentAge
* @param studentBirthday
* @param studentAddr
* @param studentQQ
*/
public Student(String studentName, String studentSex, int studentAge,
Date studentBirthday, String studentAddr, long studentQQ) {
super();
this.studentName = studentName;
this.studentSex = studentSex;
this.studentAge = studentAge;
this.studentBirthday = studentBirthday;
this.studentAddr = studentAddr;
this.studentQQ = studentQQ;
}
/**
* @return the course
*/
public Course getCourse() {
return course;
}
/**
* @param course the course to set
*/
public void setCourse(Course course) {
this.course = course;
}
}
4、新建学生课程页面ftl文件
course.ftl：
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>学生信息</title>
</head>
<body>
姓名：${student.studentName}
性别：${student.studentSex}
年龄：${student.studentAge}
生日：${(student.studentBirthday)?string("yyyy-MM-dd")}
地址：${student.studentAddr}
QQ：${student.studentQQ}
课程：${student.course!}
</body>
</html>
5、创建测试方法
/**
* 测试freemarker处理空值
* @Title:testCourse
* @Description:
* @param:
* @return: void
* @throws
*/
@Test
public void testCourse()
{
//freemarker不会处理空值
root.put("student", new Student("张三丰","男",16,new Date(1988-12-12),"湖北省武汉市武昌洪山区",78451214));
studentPrint("course.ftl");
}6、运行结果
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>学生信息</title>
</head>
<body>
姓名：张三丰
性别：男
年龄：16
生日：1970-01-01
地址：湖北省武汉市武昌洪山区
QQ：78,451,214
课程：
</body>
</html>