Spring Boot 配置Jackson
编写配置类
@Configuration
public class JacksonConfig {
@Bean
public ObjectMapper objectMapper(){
ObjectMapper objectMapper = new ObjectMapper();
//通过该方法对mapper对象进行设置，所有序列化的对象都将按改规则进行系列化
// Include.Include.ALWAYS 默认
// Include.NON_DEFAULT 属性为默认值不序列化
// Include.NON_EMPTY 属性为 空（""） 或者为 NULL 都不序列化，则返回的json是没有这个字段的。这样对移动端会更省流量
// Include.NON_NULL 属性为NULL 不序列化
objectMapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
//反序列化的时候 忽略不匹配的属性
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES,true);
// 允许出现特殊字符和转义符
objectMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS, true);
// 允许出现单引号
objectMapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
//字段保留，将null值转为"" name==null name转成""
objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {
@Override
public void serialize(Object o, JsonGenerator jsonGenerator,
SerializerProvider serializerProvider)
throws IOException {
jsonGenerator.writeString("");
}
});
//日期格式
objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd hh:mm:ss"));
objectMapper.setDefaultPropertyInclusion(JsonInclude.Include.NON_NULL);
return objectMapper;
}
}
或者配置文件
spring:
jackson:
# 设置属性命名策略,对应jackson下PropertyNamingStrategy中的常量值，SNAKE_CASE-返回的json驼峰式转下划线，json body下划线传到后端自动转驼峰式
property-naming-strategy: SNAKE_CASE
# 全局设置@JsonFormat的格式pattern
date-format: yyyy-MM-dd HH:mm:ss
# 当地时区
locale: zh
# 设置全局时区
time-zone: GMT+8
# 常用，全局设置pojo或被@JsonInclude注解的属性的序列化方式
default-property-inclusion: NON_NULL #不为空的属性才会序列化,具体属性可看JsonInclude.Include
# 常规默认,枚举类SerializationFeature中的枚举属性为key，值为boolean设置jackson序列化特性,具体key请看SerializationFeature源码
serialization:
WRITE_DATES_AS_TIMESTAMPS: true # 返回的java.util.date转换成timestamp
FAIL_ON_EMPTY_BEANS: true # 对象为空时是否报错，默认true
# 枚举类DeserializationFeature中的枚举属性为key，值为boolean设置jackson反序列化特性,具体key请看DeserializationFeature源码
deserialization:
# 常用,json中含pojo不存在属性时是否失败报错,默认true
FAIL_ON_UNKNOWN_PROPERTIES: false
# 枚举类MapperFeature中的枚举属性为key，值为boolean设置jackson ObjectMapper特性
# ObjectMapper在jackson中负责json的读写、json与pojo的互转、json tree的互转,具体特性请看MapperFeature,常规默认即可
mapper:
# 使用getter取代setter探测属性，如类中含getName()但不包含name属性与setName()，传输的vo json格式模板中依旧含name属性
USE_GETTERS_AS_SETTERS: true #默认false
# 枚举类JsonParser.Feature枚举类中的枚举属性为key，值为boolean设置jackson JsonParser特性
# JsonParser在jackson中负责json内容的读取,具体特性请看JsonParser.Feature，一般无需设置默认即可
parser:
ALLOW_SINGLE_QUOTES: true # 是否允许出现单引号,默认false
# 枚举类JsonGenerator.Feature枚举类中的枚举属性为key，值为boolean设置jackson JsonGenerator特性，一般无需设置默认即可
# JsonGenerator在jackson中负责编写json内容,具体特性请看JsonGenerator.Feature
Jackson工具类
@Component
@Slf4j
public class JacksonUtil {
@Autowired
private ObjectMapper objectMapper;
//把任意对象转成json字符串
public String writeAsString(Object obj){
try {
String s = objectMapper.writeValueAsString(obj);
return s;
}catch (JsonProcessingException e) {
log.error("object convert json exception,obj:{}",obj);
throw new RuntimeException(e);
}
}
//把json字符串转换为对象 对象得指定class
public <T>T readValue(String str,Class<T> tClass){
try {
return objectMapper.readValue(str, tClass);
} catch (JsonProcessingException e) {
log.error("str convert Object exception,str:{},class:{}",str,tClass);
throw new RuntimeException(e);
}
}
//json字符串转换为集合
public <T> List<T> readValueList(String str, Class<T> tClass){
try {
TypeFactory typeFactory = TypeFactory.defaultInstance();
return objectMapper.readValue(str,typeFactory.constructParametricType(List.class,tClass));
} catch (JsonProcessingException e) {
log.error("str convert List<Object> exception,str:{},class:{}",str,tClass);
throw new RuntimeException(e);
}
}
//json对象转成map
public <K,V> Map<K,V> readValueMap(String str, Class<K> tClass, Class<V> vClass){
try {
TypeFactory typeFactory = TypeFactory.defaultInstance();
return objectMapper.readValue(str,typeFactory.constructParametricType(HashMap.class,tClass,vClass));
} catch (JsonProcessingException e) {
log.error("str convert Map<K,V> exception,str:{},tClass:{},vClass:{}",str,tClass,vClass);
throw new RuntimeException(e);
}
}
public Map<String,String> readValueMap(String str){
try {
return objectMapper.readValue(str,HashMap.class);
} catch (JsonProcessingException e) {
log.error("str convert Map exception,str:{}",str);
throw new RuntimeException(e);
}
}
}