Spring3：Spring3+Hibernate4+RESTful+JSON配置下产生的错误结果

我在以前的文章中配置了Employee类的映射关系：

http://blog.youkuaiyun.com/ironrabbit/article/details/17137445

http://blog.youkuaiyun.com/ironrabbit/article/details/17143121

http://blog.youkuaiyun.com/ironrabbit/article/details/17142305

上述图片中的问题，应该是繁琐的实体关系导致的。那么问题来了：

1. 我们在做Spring+Hibernate的项目中，表现层和持久层到底要怎么设计？是一个实体一直用到底，还是在中间做一次转换呢？
2. 在Spring+Hibernate的配置中，到底有没有一种配置可以兼顾到Spring Controller返回JSON字串以及保持Hibernate实体间的映射呢？
3. 或者，问题根本不在Spring+Hibernate，也许我们应该用其他的东西来避免？

我的rest-servlet.xml配置文件是这样的：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p" xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <context:component-scan base-package="com.homeland.myapp.controller" />
    <mvc:annotation-driven />

    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass">
            <value>org.springframework.web.servlet.view.JstlView</value>
        </property>
        <property name="prefix">
            <value>/page/</value>
        </property>
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>

    <mvc:resources location="/images/" mapping="/images/**" />
    <mvc:resources location="/js/" mapping="/js/**" />
    <mvc:resources location="/css/" mapping="/css/**" />

    <bean id="stringHttpMessageConverter"
        class="org.springframework.http.converter.StringHttpMessageConverter" />
    <bean id="jsonHttpMessageConverter"
        class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" />
    <!-- <bean id="marshallingHttpMessageConverter" class="org.springframework.http.converter.xml.MarshallingHttpMessageConverter"> 
        <constructor-arg ref="jaxbMarshaller" /> <property name="supportedMediaTypes" value="application/xml"></property> 
        </bean> -->

    <!-- <bean id="jaxbMarshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller"> 
        <property name="classesToBeBound"> <list> <value>com.homeland.myapp.entity.Employee</value> 
        <value>com.homeland.myapp.entity.Department</value> <value>com.homeland.myapp.entity.EmployeeDetails</value> 
        <value>com.homeland.myapp.entity.Role</value> </list> </property> </bean> -->

    <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />
    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="mappingJacksonHttpMessageConverter" />
            </list>
        </property>
    </bean>
    <bean id="mappingJacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=UTF-8</value>
            </list>
        </property>
    </bean>
    <context:annotation-config />

    <!-- <bean
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="stringHttpMessageConverter" />
                <ref bean="jsonHttpMessageConverter" />
                <ref bean="marshallingHttpMessageConverter" />
            </list>
        </property>
    </bean> -->

</beans>

请自动忽略注释部分。

我的Spring Controller是这样的：

package com.homeland.myapp.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import com.homeland.myapp.entity.Employee;
import com.homeland.myapp.service.EmployeeService;

@Controller
public class EmployeeController {
	
	@Autowired
	private EmployeeService employeeService;

	@RequestMapping(method = RequestMethod.GET, value = "/employee/{id}")
	@ResponseBody
	public Employee getEmployee(@PathVariable String id) {
		Employee e = employeeService.findById(Integer.parseInt(id));
		return e;
	}
	
}

思前想后半天，还是改设计吧。别用Hibernate的复杂映射关系了。咱把表和映射都弄简单点。别因为那些眼花缭乱的配置把自己给弄傻了。

简单，易上手，易维护就OK！