PolyMapWriter827Test.java

package tools.jackson.databind.seq;

import java.util.HashMap;
import java.util.Map;

import org.junit.jupiter.api.Test;

import tools.jackson.core.JsonGenerator;
import tools.jackson.core.type.TypeReference;
import tools.jackson.databind.*;
import tools.jackson.databind.module.SimpleModule;
import tools.jackson.databind.ser.std.StdSerializer;
import tools.jackson.databind.testutil.DatabindTestUtil;
import tools.jackson.databind.testutil.NoCheckSubTypeValidator;

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

// for [databind#827]
public class PolyMapWriter827Test extends DatabindTestUtil
{
    static class CustomKey {
        String a;
        int b;

        @Override
        public String toString() { return "BAD-KEY"; }
    }

    public class CustomKeySerializer extends StdSerializer<CustomKey> {
        public CustomKeySerializer() { super(CustomKey.class); }
        @Override
        public void serialize(CustomKey key, JsonGenerator g, SerializationContext ctxt) {
            g.writeName(key.a + "," + key.b);
        }
    }

    @Test
    public void testPolyCustomKeySerializer() throws Exception
    {
        ObjectMapper mapper = jsonMapperBuilder()
                .activateDefaultTyping(NoCheckSubTypeValidator.instance,
                        DefaultTyping.NON_FINAL)
                .addModule(new SimpleModule("keySerializerModule")
                        .addKeySerializer(CustomKey.class, new CustomKeySerializer()))
                .build();
        Map<CustomKey, String> map = new HashMap<CustomKey, String>();
        CustomKey key = new CustomKey();
        key.a = "foo";
        key.b = 1;
        map.put(key, "bar");

        final ObjectWriter writer = mapper.writerFor(new TypeReference<Map<CustomKey,String>>() { });
        String json = writer.writeValueAsString(map);
        assertEquals("[\"java.util.HashMap\",{\"foo,1\":\"bar\"}]", json);
    }
}