JSON输出格式化数字字符串，保留两位小数

类注解

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
public class C {

		@JsonProperty("SCORE")
		@JsonSerialize(using = DataSerializerUtils.class)
		private String score;

		@JsonIgnore
		public String getScore() {
			return score;
		}

		public void setScore(String score) {
			this.score = score;
		}

	}

自定义序列化类

import java.io.IOException;
import java.math.RoundingMode;
import java.text.DecimalFormat;

import org.apache.commons.lang3.math.NumberUtils;

import com.alibaba.druid.util.StringUtils;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

/**
 * @author Bob.chen
 * @date 2018年11月14日-下午4:59:50
 * @desc 
 */
public class DataSerializerUtils extends JsonSerializer {

	@Override
	public void serialize(String value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
		if(!StringUtils.isEmpty(value)) {
			DecimalFormat df = new DecimalFormat("0.00");
			df.setRoundingMode(RoundingMode.HALF_UP);
			double _value = NumberUtils.toDouble(value);
			gen.writeString(df.format(_value));
		}else {//这个分支不要忘记了，否则将不输出这个属性的值
			gen.writeString(value);
		}
	}
}