Date/BigDecimal这些类型，自定义序列化和反序列化都容易导致性能变差，内置的性能优化实现，有些地方没考虑自定义序列化和反序列的情况。

遇到问题反馈过来，会逐步修复。

https://oss.sonatype.org/content/repositories/snapshots/com/alibaba/fastjson2/fastjson2/2.0.16-SNAPSHOT/
问题已经修复，请用2.0.16-SNAPSHOT帮忙验证，2.0.16版本预计在10月30日前发布

JSON.toJSONString(obj, JSONWriter.Feature.BrowserCompatible, Feature.WriteBigDecimalAsPlain)

这两个内置的Feature可能就是要的，内置的性能会更好

@wenshao
2.0.16-SNAPSHOT map里的BigDecimal还是序列化成非字符串了

package cn.nextop.gadget.json;

import java.lang.reflect.Type;
import java.math.BigDecimal;
import java.util.HashMap;
import java.util.Map;

import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONWriter;
import com.alibaba.fastjson2.writer.ObjectWriter;

/**

* @author Baoyi Chen
* /

public class Main {
	public static void main(String[] args) {
		JSON.register(Long.class, new ObjectWriter<Long>() {
			@Override
			public void write(JSONWriter jsonWriter, Object object, Object fieldName, Type fieldType, long features) {
				Long value = (Long) object;
				if (value == null) jsonWriter.writeNull(); else jsonWriter.writeString(Long.toString(value));
			}
		});

		JSON.register(BigDecimal.class, new ObjectWriter<BigDecimal>() {
			@Override
			public void write(JSONWriter jsonWriter, Object object, Object fieldName, Type fieldType, long features) {
				BigDecimal value = (BigDecimal) object;
				if (value == null) jsonWriter.writeNull(); else jsonWriter.writeString(value.toPlainString());
			}
		});

		Map<String, BigDecimal> map = new HashMap<>();
		map.put("0", new BigDecimal("0.11"));
		String s = JSON.toJSONString(map);
		System.out.println(s);

		Test t = new Test();
		t.setValue(0L);
		t.setValue1(new BigDecimal("0.11"));
		s = JSON.toJSONString(t);
		System.out.println(s);
	}

	public static class Test {
		private Long value;
		private BigDecimal value1;

		public Long getValue() {
			return value;
		}

		public void setValue(Long value) {
			this.value = value;
		}

		public BigDecimal getValue1() {
			return value1;
		}

		public void setValue1(BigDecimal value1) {
			this.value1 = value1;
		}
	}
}

期待结果

{"0":"0.11"}
{"value":"0","value1":"0.11"}

实际

{"0":0.11}
{"value":"0","value1":"0.11"}

@wenshao
包括在List中的BigDecimal和Long类型，都没有按照自定义的序列化方式进行序列化

https://oss.sonatype.org/content/repositories/snapshots/com/alibaba/fastjson2/fastjson2/2.0.16-SNAPSHOT/
问题已经修复，请用2.0.16-SNAPSHOT帮忙验证，2.0.16版本预计在10月23日前发布

https://github.com/alibaba/fastjson2/releases/tag/2.0.16
问题已修复，请用2.0.16版本

@wenshao 还是有问题

public class Main {
	public static void main(String[] args) {
		JSON.register(Long.class, new ObjectWriter<Long>() {
			@Override
			public void write(JSONWriter jsonWriter, Object object, Object fieldName, Type fieldType, long features) {
				Long value = (Long) object;
				if (value == null) jsonWriter.writeNull(); else jsonWriter.writeString(Long.toString(value));
			}
		});

		JSON.register(BigDecimal.class, new ObjectWriter<BigDecimal>() {
			@Override
			public void write(JSONWriter jsonWriter, Object object, Object fieldName, Type fieldType, long features) {
				BigDecimal value = (BigDecimal) object;
				if (value == null) jsonWriter.writeNull(); else jsonWriter.writeString(value.toPlainString());
			}
		});

		Map<String, Long> map = new HashMap<>();
		map.put("0", 0L);
		String s = JSON.toJSONString(map);
		System.out.println(s);
	}
}