SpringMVC配置@ResponseBody注解时会自动转换为JSON字符串，可像此一样自定义Date或其他类转JSON的格式

代码实现

package data;

import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.map.JsonSerializer;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializerProvider;
import org.codehaus.jackson.map.ser.CustomSerializerFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import java.io.IOException;
import java.util.Date;

import java.text.DateFormat;
import java.text.SimpleDateFormat;

/**
 * <p>Description: ResopnseBody 自动转 JSON 时，特殊类做转换</p>
 *
 * @author c332030
 * @version 1.0
 * @date 2019-3-21 10:38
 */
@Component
public class JSONDataFormat extends ObjectMapper {

    protected Logger logger = LoggerFactory.getLogger(JSONDataFormat.class);

    private static final ThreadLocal<DateFormat> dateTimeFormatThreadLocal
            = new ThreadLocal<DateFormat>() {
        @Override
        protected DateFormat initialValue() {
            return new SimpleDateFormat(defaultDatePattern);
        }
    };

    public JSONDataFormat() {
        CustomSerializerFactory factory = new CustomSerializerFactory();
        this.setSerializerFactory(factory);
    
        dateTimeFormat(factory);
    }

    /**
     * 方法用途: 日期格式化
     * 实现步骤:
     * @param factory
     * @return void
     */
    public void dateTimeFormat(CustomSerializerFactory factory) {
        factory.addGenericMapping(Date.class, new JsonSerializer<Date>() {
        
            @Override
            public void serialize(
                    Date date, JsonGenerator jsonGenerator, SerializerProvider provider
            ) throws IOException {
                jsonGenerator.writeString(dateTimeFormatThreadLocal.get().format(date));
            }
        });
    }
}

Spring配置文件

<mvc:annotation-driven>
        <mvc:message-converters>
            <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
                <property name="supportedMediaTypes">
                    <list>
                        <value>application/json;charset=UTF-8</value>
                        <value>text/html;charset=UTF-8</value>
                    </list>
                </property>

                <!-- 数据格式化 -->
                <property name="objectMapper" ref="JSONDataFormat"/>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>