[BUG] Boolean 字段private修饰 使用valueFilter 会有问题 #3076
Description
问题描述
实体中字段为Boolean时 想将对应空值转成“”时报错，
其中active 修饰为public的时候正常，
请问这种情况是设计如此还是存在bug？
补充一下 似乎 Integer也有这个问题，自定义的ObjectWriter 不生效
@DaTa
class User {
public String name;
public Integer age;
private Boolean active;
public User(String name, Integer age, Boolean active) {
this.name = name;
this.age = age;
this.active = active;
}
}
public class Fastjson2ValueFilterExample {
public static void main(String[] args) {
User user = new User("Alice", null, null);
// 定义一个 ValueFilter，将 null 值修改为默认值
ValueFilter filter = (object, name, value) -> {
if (value == null) {
return "N/A"; // 如果字段值为 null，改为 "N/A"
}
return value;
};
// 使用 ValueFilter 序列化
String jsonString = JSON.toJSONString(user, filter, JSONWriter.Feature.WriteNulls);
System.out.println(jsonString);
// 输出：{"name":"Alice","age":"N/A","active":"N/A"}
}
}
提示报错
Exception in thread "main" java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Boolean
at com.alibaba.fastjson2.writer.ObjectWriterImplBoolean.write(ObjectWriterImplBoolean.java:25)
at com.alibaba.fastjson2.writer.ObjectWriterAdapter.writeWithFilter(ObjectWriterAdapter.java:577)
at com.alibaba.fastjson2.writer.ObjectWriter3.write(ObjectWriter3.java:63)
at com.alibaba.fastjson2.JSON.toJSONString(JSON.java:3083)
at com.itime.debtdefuse.assets.util.Fastjson2ValueFilterExample.main(Fastjson2ValueFilterExample.java:34)
似乎Integer字段也有这个问题
参考代码：
import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONWriter;
import com.alibaba.fastjson2.writer.ObjectWriter;
import java.lang.reflect.Type;
import java.math.BigDecimal;
import java.util.HashMap;
import java.util.Map;
/**
-
@author Baoyi Chen
*/
public class Main {
public static void main(String[] args) {
JSON.register(Integer.class, new ObjectWriter() {
@OverRide
public void write(JSONWriter jsonWriter, Object object, Object fieldName, Type fieldType, long features) {
Integer value = (Integer) 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); Test t = new Test(); t.setValue(0); t.setValue1(new BigDecimal("0.11")); s = JSON.toJSONString(t); System.out.println(s);}
public static class Test {
private Integer value;
private BigDecimal value1;public Integer getValue() { return value; } public BigDecimal getValue1() { return value1; } public void setValue(Integer value) { this.value = value; } public void setValue1(BigDecimal value1) { this.value1 = value1; }}
}