Java Web程序中利用Spring框架返回JSON格式的日期

时间:2022-01-11 21:18:11

返回Json时格式化日期Date
第一步:创建CustomObjectMapper类

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
/**
 * 解决SpringMVC使用@ResponseBody返回json时,日期格式默认显示为时间戳的问题。需配合<mvc:message-converters>使用
 */
@Component("customObjectMapper")
public class CustomObjectMapper extends ObjectMapper {
 
  public CustomObjectMapper() {
    CustomSerializerFactory factory = new CustomSerializerFactory();
    factory.addGenericMapping(Date.class, new JsonSerializer<Date>() {
      @Override
      public void serialize(Date value, JsonGenerator jsonGenerator,
          SerializerProvider provider) throws IOException, JsonProcessingException {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        jsonGenerator.writeString(sdf.format(value));
      }
    });
    this.setSerializerFactory(factory);
  }
}

第二步:配置如下:

?
1
2
3
4
5
6
7
<mvc:annotation-driven>
  <mvc:message-converters>
    <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
      <property name="objectMapper" ref="customObjectMapper"></property>
    </bean>
  </mvc:message-converters>
</mvc:annotation-driven>

效果如下:
格式化前

Java Web程序中利用Spring框架返回JSON格式的日期

格式化后

Java Web程序中利用Spring框架返回JSON格式的日期

 

进阶:返回自定义格式日期
使用@ResponseBody时返回json字符串的日期格式。Date类型属性默认返回一个Long型的时间戳,怎样能够返回自定义的日期格式?
解决方案:目前有两种方式实现,
1、局部修改(网上较多,但不推荐);
继承Jackson的抽象类:JsonSerializer<T>,然后在javabean的属性getter()上添加注解@JsonSerialize即可实现。
代码如下:

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
 
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.map.JsonSerializer;
import org.codehaus.jackson.map.SerializerProvider;
 
/**
 * @description 自定义返回JSON 数据格中日期格式化处理
 */
public class CustomDateSerializer extends JsonSerializer<Date> {
 
  @Override
  public void serialize(Date value, 
      JsonGenerator jsonGenerator, 
      SerializerProvider provider)
      throws IOException, JsonProcessingException {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    jsonGenerator.writeString(sdf.format(value));
  }
}

使用方式: 

?
1
2
3
4
@JsonSerialize(using = CustomDateSerializer.class)
public Date getCreateDate() {
  return createDate;
}

2、全局修改(强烈推荐):
MappingJacksonHttpMessageConverter主要通过ObjectMapper来实现返回json字符串。这里我们继承该类,注册一个JsonSerializer<T>。然后在配置文件中注入自定义的ObjectMapper。
代码如下:

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
 
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonProcessingException;
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;
 
/**
 * @description 解决Date类型返回json格式为自定义格式
 */
public class CustomObjectMapper extends ObjectMapper {
 
  public CustomObjectMapper(){
    CustomSerializerFactory factory = new CustomSerializerFactory();
    factory.addGenericMapping(Date.class, new JsonSerializer<Date>(){
      @Override
      public void serialize(Date value, 
          JsonGenerator jsonGenerator, 
          SerializerProvider provider)
          throws IOException, JsonProcessingException {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        jsonGenerator.writeString(sdf.format(value));
      }
    });
    this.setSerializerFactory(factory);
  }
}

spring-servlet.xml中配置:

?
1
2
3
4
5
6
7
8
<mvc:annotation-driven>
    <mvc:message-converters>
      <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
        <property name="objectMapper" ref="customObjectMapper"></property>
      </bean>
    </mvc:message-converters>
  </mvc:annotation-driven>
  <bean id="customObjectMapper" class="com.pmc.dwa.common.custom.CustomObjectMapper"></bean>