springMVC中多个对象的数据绑定

作者: Michael 日期: 2013 年 3 月 5 日发表评论 (7) 查看评论

概述
实现方法及测试

[一]、概述

form表单中对应了多个对象而且不同对象间的属性名有相同的情况下，如何才能把页面数据准确绑定到各个对象中去呢？比如： form表单中对应了 Course （课程介绍，属性包含：name、description）和 Teacher （该课程的教师信息，属性包含：name、email、grade），两个对象中有同名的属性：name

[二]、实现方法及测试

如果多个对象之间没有同名的属性，springMVC可以实现对象的转化，如果是struts2 可以运用前缀的方式来解决，类似course.name,teacher.name，那么在这里我们可以从struts2中得到一定的启发，创建一个父级的对象CourseInfo.java 它包含了 Course 、Teacher 这两个对象：

package com.micmiu.demo.web.v2.demo.vo;

import org.apache.commons.lang3.builder.ToStringBuilder;

import com.micmiu.demo.web.v2.demo.entity.Course;
import com.micmiu.demo.web.v2.demo.entity.Teacher;

/**
 * 课程信息(view层)
 *
 * @author <a href="http://www.micmiu.com">Michael Sun</a>
 */
public class CourseInfo {

	// 课程介绍
	private Course course;

	// 老师信息
	private Teacher teacher;

	public Course getCourse() {
		return course;
	}

	public Teacher getTeacher() {
		return teacher;
	}

	public void setCourse(Course course) {
		this.course = course;
	}

	public void setTeacher(Teacher teacher) {
		this.teacher = teacher;
	}

	@Override
	public String toString() {
		return ToStringBuilder.reflectionToString(this);
	}
}

package com.micmiu.demo.web.v2.demo.vo;

import org.apache.commons.lang3.builder.ToStringBuilder;

import com.micmiu.demo.web.v2.demo.entity.Course;

import com.micmiu.demo.web.v2.demo.entity.Teacher;

/**

* 课程信息(view层)

* @author <a href="http://www.micmiu.com">Michael Sun</a>

public class CourseInfo {

// 课程介绍

private Course course;

// 老师信息

private Teacher teacher;

public Course getCourse() {

return course;

}

public Teacher getTeacher() {

return teacher;

}

public void setCourse(Course course) {

this.course = course;

}

public void setTeacher(Teacher teacher) {

this.teacher = teacher;

}

@Override

public String toString() {

return ToStringBuilder.reflectionToString(this);

}

Course.java

package com.micmiu.demo.web.v2.demo.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Table;

import org.apache.commons.lang3.builder.ToStringBuilder;

import com.micmiu.demo.web.v2.base.entity.IdEntity;

/**
 * 课程介绍
 *
 * @author <a href="http://www.micmiu.com">Michael Sun</a>
 */
@Entity
@Table(name = "T_DEMO_COURSE")
public class Course extends IdEntity {

	@Column(name = "NAME")
	private String name;

	@Column(name = "DESCRIPTION")
	private String description;

	public String getName() {
		return name;
	}

	public String getDescription() {
		return description;
	}

	public void setName(String name) {
		this.name = name;
	}

	public void setDescription(String description) {
		this.description = description;
	}

	@Override
	public String toString() {
		return ToStringBuilder.reflectionToString(this);
	}
}

package com.micmiu.demo.web.v2.demo.entity;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.Table;

import org.apache.commons.lang3.builder.ToStringBuilder;

import com.micmiu.demo.web.v2.base.entity.IdEntity;

/**

* 课程介绍

* @author <a href="http://www.micmiu.com">Michael Sun</a>

@Entity

@Table(name = "T_DEMO_COURSE")

public class Course extends IdEntity {

@Column(name = "NAME")

private String name;

@Column(name = "DESCRIPTION")

private String description;

public String getName() {

return name;

}

public String getDescription() {

return description;

}

public void setName(String name) {

this.name = name;

}

public void setDescription(String description) {

this.description = description;

}

@Override

public String toString() {

return ToStringBuilder.reflectionToString(this);

}

Teacher.java

package com.micmiu.demo.web.v2.demo.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Table;

import org.apache.commons.lang3.builder.ToStringBuilder;

import com.micmiu.demo.web.v2.base.entity.IdEntity;

/**
 * 教师信息
 *
 * @author <a href="http://www.micmiu.com">Michael Sun</a>
 */
@Entity
@Table(name = "T_DEMO_TEACHER")
public class Teacher extends IdEntity {

	@Column(name = "NAME")
	private String name;

	@Column(name = "EMAIL")
	private String email;

	@Column(name = "GRADE")
	private String grade;

	public String getName() {
		return name;
	}

	public String getEmail() {
		return email;
	}

	public String getGrade() {
		return grade;
	}

	public void setName(String name) {
		this.name = name;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	public void setGrade(String grade) {
		this.grade = grade;
	}

	@Override
	public String toString() {
		return ToStringBuilder.reflectionToString(this);
	}
}

package com.micmiu.demo.web.v2.demo.entity;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.Table;

import org.apache.commons.lang3.builder.ToStringBuilder;

import com.micmiu.demo.web.v2.base.entity.IdEntity;

/**

* 教师信息

* @author <a href="http://www.micmiu.com">Michael Sun</a>

@Entity

@Table(name = "T_DEMO_TEACHER")

public class Teacher extends IdEntity {

@Column(name = "NAME")

private String name;

@Column(name = "EMAIL")

private String email;

@Column(name = "GRADE")

private String grade;

public String getName() {

return name;

}

public String getEmail() {

return email;

}

public String getGrade() {

return grade;

}

public void setName(String name) {

this.name = name;

}

public void setEmail(String email) {

this.email = email;

}

public void setGrade(String grade) {

this.grade = grade;

}

@Override

public String toString() {

return ToStringBuilder.reflectionToString(this);

}

view页面中 form表单内容如下：

<form:form id="input-form" modelAttribute="courseInfo"
	action="${ctx}/demo/course.do?method=save" method="post">
	<input type="hidden" name="id" value="${course.id}" />
	<fieldset class="prepend-top">
		<legend>课程信息</legend>
		<div id="messageBox" class="error-msg" style="display: none">输入有误，请先更正。</div>
		<div>
			<label for="course.name" class="field">课程名称:</label> <input
				type="text" id="course.name" name="course.name" size="20"
				value="${courseInfo.course.name}" class="required" />
		</div>
		<div>
			<label for="course.description" class="field">课程介绍:</label> <input
				type="text" id="course.description" name="course.description" size="20"
				value="${courseInfo.course.description}" class="required" />
		</div>

		<div>
			<label for="teacher.name" class="field">老师姓名:</label> <input
				type="text" id="teacher.name" name="teacher.name" size="20"
				value="${courseInfo.teacher.name}" class="required" />
		</div>
		<div>
			<label for="teacher.email" class="field">老师Email:</label> <input
				type="text" id="teacher.email" name="teacher.email" size="20"
				value="${courseInfo.teacher.email}" class="required" />
		</div>
	</fieldset>
</form:form>

<form:form id="input-form" modelAttribute="courseInfo"

action="${ctx}/demo/course.do?method=save" method="post">

<div>

<label for="course.name" class="field">课程名称:</label> <input

type="text" id="course.name" name="course.name" size="20"

value="${courseInfo.course.name}" class="required" />

</div>

<div>

<label for="course.description" class="field">课程介绍:</label> <input

type="text" id="course.description" name="course.description" size="20"

value="${courseInfo.course.description}" class="required" />

</div>

<div>

<label for="teacher.name" class="field">老师姓名:</label> <input

type="text" id="teacher.name" name="teacher.name" size="20"

value="${courseInfo.teacher.name}" class="required" />

</div>

<div>

<label for="teacher.email" class="field">老师Email:</label> <input

type="text" id="teacher.email" name="teacher.email" size="20"

value="${courseInfo.teacher.email}" class="required" />

</div>

</fieldset>

</form:form>

注意：加前缀来区分

controller 的实现CourseAction.java 如下：

package com.micmiu.demo.web.v2.demo.action;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;

import com.micmiu.demo.web.v2.demo.entity.Course;
import com.micmiu.demo.web.v2.demo.entity.Student;
import com.micmiu.demo.web.v2.demo.entity.Teacher;
import com.micmiu.demo.web.v2.demo.vo.CourseInfo;

/**
 *
 * @author <a href="http://www.micmiu.com">Michael Sun</a>
 */
@Controller
@RequestMapping(value = "/demo/course.do")
public class CourseAction {

	@RequestMapping(params = { "method=list" })
	public String list(Model model) {
		return "course.list";
	}

	@RequestMapping(params = { "method=save" })
	@ResponseBody
	public String save(Model model, ModelAndView mv, CourseInfo courseInfo,
			RedirectAttributes redirectAttributes) {
		System.out.println("course >> " + courseInfo.getCourse());
		System.out.println("teacher >> " + courseInfo.getTeacher());
		String message = "save";
		redirectAttributes.addFlashAttribute("message", message);
		return message;
	}

}

package com.micmiu.demo.web.v2.demo.action;

import java.util.Collections;

import java.util.HashMap;

import java.util.Map;

import org.springframework.stereotype.Controller;

import org.springframework.ui.Model;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.ResponseBody;

import org.springframework.web.servlet.ModelAndView;

import org.springframework.web.servlet.mvc.support.RedirectAttributes;

import com.micmiu.demo.web.v2.demo.entity.Course;

import com.micmiu.demo.web.v2.demo.entity.Student;

import com.micmiu.demo.web.v2.demo.entity.Teacher;

import com.micmiu.demo.web.v2.demo.vo.CourseInfo;

/**

* @author <a href="http://www.micmiu.com">Michael Sun</a>

@Controller

@RequestMapping(value = "/demo/course.do")

public class CourseAction {

@RequestMapping(params = { "method=list" })

public String list(Model model) {

return "course.list";

}

@RequestMapping(params = { "method=save" })

@ResponseBody

public String save(Model model, ModelAndView mv, CourseInfo courseInfo,

RedirectAttributes redirectAttributes) {

System.out.println("course >> " + courseInfo.getCourse());

System.out.println("teacher >> " + courseInfo.getTeacher());

String message = "save";

redirectAttributes.addFlashAttribute("message", message);

return message;

}

controller中的部分方法省略，这里主要测试下页面数据绑定的结果，测试过程如下：

表单输入内容如下图：

提交后，控制台输出日志如下：

course >> com.micmiu.demo.web.v2.demo.entity.Course@1fa1838[name=课程名称,description=课程介绍,id=<null>]
teacher >> com.micmiu.demo.web.v2.demo.entity.Teacher@4c2c86[name=老师姓名,email=老师Email,grade=<null>,id=<null>]

1 2	course >> com.micmiu.demo.web.v2.demo.entity.Course@1fa1838[name=课程名称,description=课程介绍,id=<null>] teacher >> com.micmiu.demo.web.v2.demo.entity.Teacher@4c2c86[name=老师姓名,email=老师Email,grade=<null>,id=<null>]

从日志中可以看出：创建父级对象后，利用前缀区分的方式可以实现多个对象的数据准确绑定。

本文介绍到此结束@Michael Sun.

原创文章，转载请注明： 转载自micmiu – 软件开发+生活点滴[ http://www.micmiu.com/ ]

本文链接地址: http://www.micmiu.com/j2ee/spring/springmvc-view-mulit-bean/

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发表评论？

7 条评论。

jast 2015 年 3 月 25 日在下午 5:00

在VO直接访问PO真的好？

回复
- Michael 2015 年 3 月 25 日在下午 5:17
  
  这个嘛。。。不讨论vo po bo ，适用最好你说是吗
  
  回复
gogo 2014 年 6 月 27 日在上午 11:50

这种方法不灵活，更好的方式的实现HandlerMethodArgumentResolver接口。
http://www.cnblogs.com/fangjian0423/p/springMVC-request-param-analysis.html#demo

回复
DolphinBoy 2013 年 9 月 4 日在上午 9:57

创建父级对象貌似不是最好的办法, 感觉也很麻烦, 如果有N个累死的情况呢, 难道都要创建父级对象啊?

回复
- Michael 2013 年 9 月 4 日在上午 9:59
  
  这个只是一种既要用spring mvc 又不想扩展源码的折中解决办法
  
  回复
我是游客 2013 年 5 月 13 日在下午 6:22

😯
请问，就这样就ok了嘛？
不需要额外配置什么处理器啥的么。我奇怪的是他们怎么封装成对象的啊。。。

回复
- Michael 2013 年 5 月 20 日在上午 9:03
  
  我是在3.2上实现的好像2.x 不支持
  
  回复

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