Spring Boot中如何使用Convert接口实现类型转换器

public interface Converter<S, T> {       
    T convert(S source);     
} 

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

public class User {
  private long  id;
  //用户名
  private String name;
  //出生日期
  private Date birth;
  //关联用户
  private User linkUser;
  //喜欢的文章
  private List<Article> favArticles=new ArrayList<>();
 //下面省略Getter和Setter方法

public class Article {
  //文章id
  private long artId;
  //文章名
  private String artName;
  
 //下面省略Getter和Setter方法
}

@Component
public class DateConvert implements Converter<String,Date> {
  //日期格式
 SimpleDateFORMat sdf=new SimpleDateFormat("yyyy-MM-dd");
  @Override
  public Date convert(String s) {
    if (s!=null&&!"".equals(s)){
      try {
        //解析参数
        Date date=sdf.parse(s);
        return date;
      } catch (ParseException e) {
        e.printStackTrace();
      }
    }
    return null;
  }
}

@Component
public class ObjectConvert implements Converter<String,User> {
  @Override
  public User convert(String s) {
    ObjectMapper objectMapper=new ObjectMapper();
    if (s!=null&&!"".equals(s)){
      try {
        User user=objectMapper.readValue(s,User.class);
        return user;
      } catch (jsonProcessingException e) {
        e.printStackTrace();
      }
    }
    return null;
  }
}

@Component
public class StringToListController implements Converter<String, List<Article>> {
 ObjectMapper objectMapper=new ObjectMapper();
  @Override
  public List<Article> convert(String s) {
    List<Article> list=null;
    try {
       list=objectMapper.readValue(s, new TypeReference<List<Article>>() {
      });
    } catch (JsonProcessingException e) {
      e.printStackTrace();
    }
    return list;
  }
}

@RestController
public class HelloController {
  @GetMapping("hello")
  public Date getDate(Date birth){
    System.out.println(birth);
    return birth;
  }
  @PostMapping(value="showUser",produces="application/json",
          consumes = "application/x-www-form-urlencoded")
  public User showUser(User user){
    return user;
  }
}

<!-- 属性编辑器 -->
    <bean id="conversionService"
        class="org.springframework.format.support.FormattinGConversionServiceFactoryBean">
        <property name="converters">
            <list>
                <bean class="com.xxx.common.converter.StringTrimConverter" />
                <bean class="com.xxx.common.converter.DateConverter" />
                <bean class="com.xxx.common.converter.DatetimeConverter" />
            </list>
        </property>
    </bean>
<mvc:annotation-driven conversion-service="conversionService">

import org.springframework.core.convert.converter.Converter;

public class StringTrimConverter implements Converter<String, String> {
    public String convert(String source) {
        //如果源字符串不为空则进行转换
        if(source != null){
            //去除源字符串前后空格
            source = source.trim();
            if(source.equals("")){ 
                source = null;
            }
        }
        return source;
    }
}

public interface Converter<S, T> {
    
    T convert(S source);
}

public class DateConverter implements Converter
<bean id="conversionService"
        class="org.springframework.format.support.FormattingConversionServiceFactoryBean">

* <p>Like all {@code FactoryBean} implementations, this class is suitable for
 * use when configuring a Spring application context using Spring {@code <beans>}
 * XML. When configuring the container with
 * {@link org.springframework.context.annotation.Configuration @Configuration}
 * classes, simply instantiate, configure and return the appropriate
 * {@code FormattingConversionService} object from a
 * {@link org.springframework.context.annotation.Bean @Bean} method.

public class FormattingConversionServiceFactoryBean
        implements FactoryBean<FormattingConversionService>, EmbeddedValueResolverAware, InitializingBean {
    private Set<?> converters;
    private Set<?> formatters;
    private Set<FormatterReGIStrar> formatterRegistrars;
    private boolean registerDefaultFormatters = true;
    private StringValueResolver embeddedValueResolver;
    private FormattingConversionService conversionService;

@Override
    public void afterPropertiesSet() {
        this.conversionService = new DefaultFormattingConversionService(this.embeddedValueResolver, this.registerDefaultFormatters);
        ConversionServiceFactory.registerConverters(this.converters, this.conversionService);
        registerFormatters();
    }

public static void registerConverters(Set<?> converters, ConverterRegistry registry) {
        if (converters != null) {
            for (Object converter : converters) {
                if (converter instanceof GenericConverter) {
                    registry.addConverter((GenericConverter) converter);
                }
                else if (converter instanceof Converter<?, ?>) {
                    registry.addConverter((Converter<?, ?>) converter);
                }
                else if (converter instanceof ConverterFactory<?, ?>) {
                    registry.addConverterFactory((ConverterFactory<?, ?>) converter);
                }
                else {
                    throw new IllegalArgumentException("Each converter object must implement one of the " +
                            "Converter, ConverterFactory, or GenericConverter interfaces");
                }
            }
        }
    }