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;
  //用戶名
  private String name;
  //出生日期
  private Date birth;
  //關(guān)聯(lián)用戶
  private User linkUser;
  //喜歡的文章
  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 {
        //解析參數(shù)
        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;
  }
}

<!-- 屬性編輯器 -->
    <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;
/**
 * 去除前后空格
 * @author 
 *
 */
public class StringTrimConverter implements Converter<String, String> {
    public String convert(String source) {
        //如果源字符串不為空則進(jìn)行轉(zhuǎn)換
        if(source != null){
            //去除源字符串前后空格
            source = source.trim();
            if(source.equals("")){ 
                source = null;
            }
        }
        return source;
    }
}

/**
 * A converter converts a source object of type S to a target of type T.
 * Implementations of this interface are thread-safe and can be shared.
 *
 * <p>Implementations may additionally implement {@link ConditionalConverter}.
 *
 * @author Keith Donald
 * @since 3.0
 * @see ConditionalConverter
 * @param <S> The source type
 * @param <T> The target type
 */
public interface Converter<S, T> {
    /**
     * Convert the source of type S to target type T.
     * @param source the source object to convert, which must be an instance of S
     * @return the converted object, which must be an instance of T
     * @throws IllegalArgumentException if the source could not be converted to the desired target type
     */
    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");
                }
            }
        }
    }