@JsonSerialize序列化注解的使用

package com.test.hello.vo;
 
import com.test.hello.utils.Customer1DoubleSerialize;
import com.test.hello.utils.CustomerDoubleSerialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import io.swagger.annotations.ApiModelProperty;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
 
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class TestVo {
 
    //使用方法，直接加载需要保留小数的字段上
    @JsonSerialize(using = Customer1DoubleSerialize.class)
    private Double num;
 
    @ApiModelProperty("id")
    private String Id;
 
    @ApiModelProperty("名")
    private String name;
 
    @ApiModelProperty("数据类型")
    @ExcelProperty(converter = UnitConverter.class)
    private String dataType;
 
 
}

package com.test.hello.utils;
 
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
 
import java.io.IOException;
import java.math.RoundingMode;
import java.text.DecimalFormat;
 
public class Customer1DoubleSerialize extends JsonSerializer {
    private DecimalFormat df = new DecimalFormat("0.0");
    @Override
    public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
        df.setRoundingMode(RoundingMode.HALF_DOWN);
        if(o.toString() != null && !"-".equals(o)) {
            Double dd=Double.parseDouble(o.toString());
 
            jsonGenerator.writeString(df.format(dd));
 
        } else{
            jsonGenerator.writeString(o.toString());
 
        }
    }
}

package com.test.hello.utils;
 
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
 
import java.io.IOException;
import java.math.RoundingMode;
import java.text.DecimalFormat;
 
public class CustomerDoubleSerialize extends JsonSerializer {
    private DecimalFormat df = new DecimalFormat("0.00");
    @Override
    public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
        df.setRoundingMode(RoundingMode.HALF_DOWN);
        if(o.toString() != null && !"-".equals(o)) {
            Double dd=Double.parseDouble(o.toString());
 
            jsonGenerator.writeString(df.format(dd));
 
        } else{
            jsonGenerator.writeString(o.toString());
 
        }
    }
}

package com.test.hello.utils;
 
import com.alibaba.excel.converters.Converter;
import com.alibaba.excel.enums.CellDataTypeEnum;
import com.alibaba.excel.metadata.GlobalConfiguration;
import com.alibaba.excel.metadata.data.WriteCellData;
import com.alibaba.excel.metadata.property.ExcelContentProperty;
 
public class UnitConverter implements Converter<String> {
    @Override
    public Class<?> supportJavaTypeKey() {
        return Converter.super.supportJavaTypeKey();
    }
 
    @Override
    public CellDataTypeEnum supportExcelTypeKey() {
        return Converter.super.supportExcelTypeKey();
    }
 
    @Override
    public WriteCellData<?> convertToExcelData(String value, ExcelContentProperty contentProperty, GlobalConfiguration globalConfiguration) throws Exception {
        String dateValue = "";
        if (value.equals("2D")) {
            dateValue = "km";
        } else if (value.equals("3D")) {
            dateValue = "km2";
        }
        return new WriteCellData<>(dateValue);
    }
}