SpringMVC 中 数据绑定 数据转换 自定义数据转换器

input.jsp页面加入这样的方式，将一个字符串提交到后台。

后台用SpringMVCTest.java处理它。但是这个处理是将字符串转换成对象，所以我们得去配置EmployeeConverter自定义的对象。

package com.hust.springmvc.test; import com.hust.springmvc.dao.EmployDao; import com.hust.springmvc.entities.Employee; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; /** * Created by yexx on 16-11-11. */ @Controller public class SpringMVCTest { @Autowired private EmployDao employDao; @RequestMapping(value = "/testConversionServiceConverter", method = RequestMethod.POST) public String testConverter(@RequestParam("employee") Employee employee) { System.out.print("save:" + employee); employDao.save(employee); return "redirect:/emps"; } }

EmployeeConverter.java

package com.hust.springmvc.converters; import com.hust.springmvc.dao.DepartmentDao; import com.hust.springmvc.entities.Department; import com.hust.springmvc.entities.Employee; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.core.convert.converter.Converter; import org.springframework.stereotype.Component; /** * Created by yexx on 16-11-11. */ @Component public class EmployeeConverter implements Converter<String, Employee> { @Autowired private DepartmentDao departmentDao; @Override public Employee convert(String s) { if (s != null) { String[] vals = s.split("-"); if (vals != null && vals.length == 4) { String lastName = vals[0]; String email = vals[1]; Integer gender = Integer.parseInt(vals[2]); Employee employee = new Employee(null, lastName, email, gender, departmentDao.getDepartment(Integer.parseInt(vals[3]))); System.out.println(s + "--convert--" + employee); return employee; } } return null; } }

在SpringMVC的配置文件配置如下。配置conversionService，而且还要在mvc：annotation-driven配置一下conversion-service。

<mvc:annotation-driven conversion-service="conversionService"></mvc:annotation-driven> <!-- 配置 ConversionService --> <bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean"> <property name="converters"> <set> <ref bean="employeeConverter"/> </set> </property> </bean>

这样就能进行自定义数据转换器的功能了，会按照自定义的字符串的格式转换为相应的对象。

跟踪流程：

先在字符串进来的地方打断点，debug模式进入，找到resolveArgument，找到binder。

找到conversionService

找到最底下我们自己自定义的数据转换器，看到了包名了吧，还有String类型的。可以把他们加到watches，看到具体情况。

运行截图