在項(xiàng)目開(kāi)發(fā)中，我們返回的數(shù)據(jù)或者對(duì)象沒(méi)有的時(shí)候一般直接返回的null

有數(shù)據(jù)時(shí)的返回值

{ 'flag': true, 'code': '10000', 'msg': '成功！', 'data': { 'id': 32, 'templateType': 1, 'templateName': '我的測(cè)試模板1', 'freightName': '我的測(cè)試標(biāo)題1', 'listArea': [ { 'id': 968, 'templateId': 32, 'freightPrice': 15, } ], 'templateDescEntity': { 'id': 1 'name': 'xxx' } }}

沒(méi)有數(shù)據(jù)時(shí)的返回值

{ 'flag': true, 'code': '10000', 'msg': '成功！', 'data': { 'id': 32, 'templateType': 1, 'templateName': null, 'freightName': null, 'listArea': null, 'templateDescEntity': null }}

這種情況下數(shù)據(jù)返回給前端，前端需要做大量的空值判斷如前端調(diào)使用屬性data.templateDescEntity.id的時(shí)候就會(huì)直接報(bào)異常此時(shí)我們可以使用返回值統(tǒng)一處理，配置如下

pom.xml添加

<dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-annotations</artifactId> <version>2.9.5</version></dependency><dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId></dependency>

java類(lèi)添加配置

package com.ys.mall.core.product.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.lang.reflect.Field;import java.util.Collection;import java.util.List;import java.util.Map;import java.util.Objects;/** * 數(shù)據(jù)返回給前端時(shí)，設(shè)置null值默認(rèn)為'' * * @author cgh * @date 2020/12/14 10:35 */@Configurationpublic class JacksonConfig { @Bean @Primary @ConditionalOnMissingBean(ObjectMapper.class) public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {ObjectMapper objectMapper = builder.createXmlMapper(false).build();objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() { @Override public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {String fieldName = jsonGenerator.getOutputContext().getCurrentName();try { //反射獲取字段類(lèi)型 Field field = jsonGenerator.getCurrentValue().getClass().getDeclaredField(fieldName); if (CharSequence.class.isAssignableFrom(field.getType())) {//字符串型空值''jsonGenerator.writeString('');return; } else if (Collection.class.isAssignableFrom(field.getType())) {//列表型空值返回[]jsonGenerator.writeStartArray();jsonGenerator.writeEndArray();return; } else if (Map.class.isAssignableFrom(field.getType())) {//map型空值 或者 bean對(duì)象 返回{}jsonGenerator.writeStartObject();jsonGenerator.writeEndObject();return; }} catch (NoSuchFieldException ignored) {}jsonGenerator.writeString(''); }});return objectMapper; }}

添加空值統(tǒng)一處理后的返回值

{ 'flag': true, 'code': '10000', 'msg': '成功！', 'data': { 'id': 32, 'templateType': 1, 'templateName': '', 'freightName': '', 'listArea': [], 'templateDescEntity': {} }}

到此這篇關(guān)于springboot配置Jackson返回統(tǒng)一默認(rèn)值的實(shí)現(xiàn)示例的文章就介紹到這了,更多相關(guān)springboot Jackson返回統(tǒng)一默認(rèn)值內(nèi)容請(qǐng)搜索好吧啦網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持好吧啦網(wǎng)！