[BUG] Deserialization includes additional @type information after WriteClassName

[Cooper-Zhong]

问题描述

Map序列化配置WriteClassName后，反序列化会多出类型信息的entry（配置SupportAutoType也是），在fastjson 1.2.83上没有这个问题

环境信息

• OS信息： [MacOS 12.7.4 M1 Pro 16 GB]
• JDK信息： [Openjdk 17.0.6]
• 版本信息：[Fastjson2 2.0.50]

重现步骤

import com.alibaba.fastjson.serializer.SerializerFeature;
import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONWriter;
import org.junit.jupiter.api.Test;

import java.util.HashMap;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class Issue336Mutated_758 {

    @Test
    public void testEmpty() {
        HashMap<String, String> map = new HashMap<>();
        map.put("date", "2022");
        String jsonString = JSON.toJSONString(map, JSONWriter.Feature.WriteClassName);
//        HashMap result = JSON.parseObject(jsonString, HashMap.class, JSONReader.Feature.SupportAutoType);
        HashMap result = JSON.parseObject(jsonString, HashMap.class);
        assertEquals(1, result.size());
    }

    @Test
    public void testEmpty1() {
        HashMap<String, String> map = new HashMap<>();
        map.put("date", "2022");
        String jsonString = com.alibaba.fastjson.JSON.toJSONString(map, SerializerFeature.WriteClassName);
        HashMap result = com.alibaba.fastjson.JSON.parseObject(jsonString, HashMap.class);
        assertEquals(1, result.size());
    }
}

期待的正确结果

不含有@type -> java.util.HashMap项

[wenshao]

WriteClassName在parse时应该和SupportAutoType配对使用，这个不是BUG

[Cooper-Zhong]

public void test() {
        HashMap<String, String> map = new HashMap<>();
        map.put("date", "2022");
        String jsonString = JSON.toJSONString(map, JSONWriter.Feature.WriteClassName);
        HashMap result = JSON.parseObject(jsonString, HashMap.class, JSONReader.Feature.SupportAutoType);
        System.out.println(JSON.toJSONString(result));
        // {"date":"2022","@type":"java.util.HashMap"}
        assertEquals(1, result.size());
    }

是配对使用的，但在parse后的map entry里面依然保留着类型信息@type -> java.util.HashMap

[wenshao]

https://oss.sonatype.org/content/repositories/snapshots/com/alibaba/fastjson2/fastjson2/2.0.51-SNAPSHOT/
问题已修复，请帮忙用2.0.51-SNAPSHOT版本验证

[Cooper-Zhong]

验证已修复，辛苦温少

[wenshao]

https://github.com/alibaba/fastjson2/releases/tag/2.0.51
问题已修复，请用新版本