# 项目中全局处理Null值为空字符串

**Repository Path**: fpfgitmy_admin/project-handle-null

## Basic Information

- **Project Name**: 项目中全局处理Null值为空字符串
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 1
- **Forks**: 0
- **Created**: 2021-04-28
- **Last Updated**: 2021-04-28

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

#### 全局处理Null值为空字符串
```
package com.example.demo.config;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializerProvider;

import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;

import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;

import java.io.IOException;

import java.text.SimpleDateFormat;


/**
 * @Author felix fei
 * @Date 2021/1/28 0028 14:52
 * @Version 1.0.1
 * @describe: 将返回为null的值改为""
 */
@Configuration
public class JacksonConfig {
    @Bean
    @Primary
    @ConditionalOnMissingBean(ObjectMapper.class)
    public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
        ObjectMapper objectMapper = builder.createXmlMapper(false).build();
        objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss")); //可将日期型的字段统一格式化
        objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {
                @Override
                public void serialize(Object o, JsonGenerator jsonGenerator,
                    SerializerProvider serializerProvider)
                    throws IOException {
                    jsonGenerator.writeString("");
                }
            });

        return objectMapper;
    }
}
```