SpringBoot的json序列化及时间序列化处理

使用场景：前台的多种时间格式存入后台，后台返回同时的时间格式到前台。

1 在config目录下配置jscksonConfig.java

package com.test.domi.config;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Primary;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
import java.io.IOException;
import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * 时间序列化
 */
public class JacksonConfig {

    @Bean
    @Primary
    @ConditionalOnMissingBean
    public ObjectMapper jacksonOnjectMapper(Jackson2ObjectMapperBuilder builder){
        ObjectMapper objectMapper = builder.createXmlMapper(false).build();
        //将json属性的空值null转化为空字符串""
        objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {
            @Override
            public void serialize(Object arg0, JsonGenerator arg1, SerializerProvider arg2) throws IOException, JsonProcessingException {
                arg1.writeString("");
            }
        });
        //json转换日期格式设置
        objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd"));
        SimpleModule simpleModule = new SimpleModule();
        //在进出前后台的时候，设置BigDecimal和字符串之间转换
        simpleModule.addSerializer(BigDecimal.class,ToStringSerializer.instance);
        //设置对前台传入的多种格式的时间都支持序列化
        simpleModule.addDeserializer(Date.class,CommonDateDeserializer.INSTANCE);
        objectMapper.registerModule(simpleModule);
        return objectMapper;
    }
}

二 在config目录下CommonDateDeserializer继承stdScalarDeserializer序列化类，重写deserialize序列化设置方法

package com.test.domi.config;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.deser.std.StdScalarDeserializer;
import org.apache.commons.lang.time.DateUtils;
import java.io.IOException;
import java.text.ParseException;
import java.util.Date;

public class CommonDateDeserializer extends StdScalarDeserializer {

    public  static final CommonDateDeserializer INSTANCE = new CommonDateDeserializer(Date.class);
    private final String[] DATE_FORMAT_STRS = {"yyyy-MM-dd","yyyy/MM/dd"};

    protected CommonDateDeserializer(Class vc) {
        super(vc);
    }

    @Override
    public Object deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
        JsonToken t = jsonParser.getCurrentToken();
        if (t == JsonToken.VALUE_STRING) {
            String str = jsonParser.getText().trim();
            if (str.length() == 0) {
                return getEmptyValue(deserializationContext);
            }
            try {
                return DateUtils.parseDate(str,DATE_FORMAT_STRS);
            } catch (ParseException e) {
                return (java.util.Date)deserializationContext.handleWeirdStringValue(handledType(),str,"expected format \"%s\"");
            }
        }

        if (t == JsonToken.START_ARRAY && deserializationContext.isEnabled(DeserializationFeature.UNWRAP_SINGLE_VALUE_ARRAYS)) {
            jsonParser.nextToken();
            final Date parsed = _parseDate(jsonParser,deserializationContext);
            t = jsonParser.nextToken();
            if (t != JsonToken.END_ARRAY) {
                handleMissingEndArrayForSingle(jsonParser,deserializationContext);
            }
            return parsed;
        }
        return super._parseDate(jsonParser,deserializationContext);
    }
}