springboot时间格式化与空值格式化
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.deser.*;
import com.fasterxml.jackson.databind.ser.BeanPropertyWriter;
import com.fasterxml.jackson.databind.ser.BeanSerializerModifier;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import org.apache.commons.lang3.StringUtils;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.*;
class JacksonHttpMessageConverter extends MappingJackson2HttpMessageConverter {
/**
* 处理数组类型的null值
*/
public class NullArrayJsonSerializer extends JsonSerializer<Object> {
@Override
public void serialize(Object value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
if (value == null) {
jgen.writeStartArray();
jgen.writeEndArray();
}
}
}
/**
* 处理字符串类型的null值
*/
public class NullStringJsonSerializer extends JsonSerializer<Object> {
@Override
public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
jsonGenerator.writeString(StringUtils.EMPTY);
}
}
/**
* 处理数字类型的null值
*/
public class NullNumberJsonSerializer extends JsonSerializer<Object> {
@Override
public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
jsonGenerator.writeNumber(0);
}
}
/**
* 处理布尔类型的null值
*/
public class NullBooleanJsonSerializer extends JsonSerializer<Object> {
@Override
public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
jsonGenerator.writeBoolean(false);
}
}
/**
* 处理LocalDateTime类型的值
*/
public class LocalDateTimeSerializer extends JsonSerializer<Object> {
private final DateTimeFormatter formatter= DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:");
@Override
public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
jsonGenerator.writeString(formatter.format((LocalDateTime) o));
}
}
/**
* 处理LocalDateTime类型的值
*/
public class LocalDateSerializer extends JsonSerializer<Object> {
private final DateTimeFormatter formatter= DateTimeFormatter.ofPattern("yyyy年MM月dd日");
@Override
public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
jsonGenerator.writeString(formatter.format((LocalDate) o));
}
}
//序列化修改器
public class MyBeanSerializerModifier extends BeanSerializerModifier {
@Override
public List<BeanPropertyWriter> changeProperties(SerializationConfig config, BeanDescription beanDesc, List<BeanPropertyWriter> beanProperties) {
//循环所有的beanPropertyWriter
for (Object beanProperty : beanProperties) {
BeanPropertyWriter writer = (BeanPropertyWriter) beanProperty;
//判断字段的类型，如果是array，list，set则注册nullSerializer
if (isArrayType(writer)) {
//给writer注册一个自己的nullSerializer
writer.assignNullSerializer(new NullArrayJsonSerializer());
} else if (isNumberType(writer)) {
writer.assignNullSerializer(new NullNumberJsonSerializer());
} else if (isBooleanType(writer)) {
writer.assignNullSerializer(new NullBooleanJsonSerializer());
} else if (isStringType(writer)) {
writer.assignNullSerializer(new NullStringJsonSerializer());
} else if (isDateType(writer)){
writer.assignNullSerializer(new NullStringJsonSerializer());
}
else if (isLcDateTimeType(writer)) {
//非空使用自定义序列化方式
writer.assignSerializer(new LocalDateTimeSerializer());
writer.assignNullSerializer(new NullStringJsonSerializer());
}else if (isLcDateType(writer)) {
//非空使用自定义序列化方式
writer.assignSerializer(new LocalDateSerializer());
writer.assignNullSerializer(new NullStringJsonSerializer());
}
}
return beanProperties;
}
/**
* 是否是数组
*/
private boolean isArrayType(BeanPropertyWriter writer) {
Class<?> clazz = writer.getType().getRawClass();
return clazz.isArray() || Collection.class.isAssignableFrom(clazz);
}
/**
* 是否是string
*/
private boolean isStringType(BeanPropertyWriter writer) {
Class<?> clazz = writer.getType().getRawClass();
return CharSequence.class.isAssignableFrom(clazz) || Character.class.isAssignableFrom(clazz);
}
/**
* 是否是int
*/
private boolean isNumberType(BeanPropertyWriter writer) {
Class<?> clazz = writer.getType().getRawClass();
return Number.class.isAssignableFrom(clazz);
}
/**
* 是否是boolean
*/
private boolean isBooleanType(BeanPropertyWriter writer) {
Class<?> clazz = writer.getType().getRawClass();
return clazz.equals(Boolean.class);
}
/**
* 是否是LocalDate
*/
private boolean isDateType(BeanPropertyWriter writer) {
Class<?> clazz = writer.getType().getRawClass();
return clazz.equals(Date.class);
}
/**
* 是否是LocalDate
*/
private boolean isLcDateType(BeanPropertyWriter writer) {
Class<?> clazz = writer.getType().getRawClass();
return clazz.equals(LocalDate.class);
}
/**
* 是否是LocalDateTime
*/
private boolean isLcDateTimeType(BeanPropertyWriter writer) {
Class<?> clazz = writer.getType().getRawClass();
return clazz.equals(LocalDateTime.class);
}
}
//反序列化修改器
public class MyBeanDeSerializerModifier extends BeanDeserializerModifier {
@Override
public JsonDeserializer<?> modifyDeserializer(DeserializationConfig config, BeanDescription beanDesc, JsonDeserializer<?> deserializer) {
Class<?> aClass = deserializer.handledType();
if (aClass.equals(LocalDateTime.class)) {
deserializer=new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:"));
}
if (aClass.equals(LocalDate.class)) {
deserializer=new LocalDateDeserializer(DateTimeFormatter.ofPattern("yyyy年MM月dd日"));
}
return deserializer;
}
}
//自定义转换会让全局LocalDateTime序列化失效,默认转Long型
JacksonHttpMessageConverter() {
DeserializerFactory dFactory = BeanDeserializerFactory.instance.withDeserializerModifier(new MyBeanDeSerializerModifier());
ObjectMapper objectMapper = new ObjectMapper(null, null, new DefaultDeserializationContext.Impl(dFactory));
objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"))//只对Date生效
.setSerializerFactory(getObjectMapper().getSerializerFactory().withSerializerModifier(new MyBeanSerializerModifier()));
setObjectMapper(objectMapper);
}
}