Question

  public class TestJacksonColor {
        public static void main(String [] args) throws IOException {
            ObjectMapper objectMapper = new ObjectMapper();
            Color black = new Color(0, 0, 0);
            String json = objectMapper.writeValueAsString(black);
            Color backToObject = objectMapper.readValue(json, Color.class);
        }
    }

代码尝试使用jackson objectmapper将java.awt.color类序列化。获取生成的json字符串并将其反序列化为java.awt.color类。但是，在执行反序列化时会发生以下错误。

线程中的异常＆＃34; main＆＃34; com.fasterxml.jackson.databind.JsonMappingException：找不到类型[simple type，class java.awt.Color]的合适构造函数：无法从JSON对象实例化

Answer 1

您需要自定义序列化程序和反序列化程序。有一些预先构建的modules，但我不知道处理java.awt.Color的人。Color。

这是一个定义序列化器/解串器对并注册模块来处理public class JacksonColorTest { public static class ColorSerializer extends JsonSerializer<Color> { @Override public void serialize(Color value, JsonGenerator gen, SerializerProvider serializers) throws IOException { gen.writeStartObject(); gen.writeFieldName("argb"); gen.writeString(Integer.toHexString(value.getRGB())); gen.writeEndObject(); } } public static class ColorDeserializer extends JsonDeserializer<Color> { @Override public Color deserialize(JsonParser p, DeserializationContext ctxt) throws IOException { TreeNode root = p.getCodec().readTree(p); TextNode rgba = (TextNode) root.get("argb"); return new Color(Integer.parseUnsignedInt(rgba.textValue(), 16), true); } } public static void main(String [] args) throws IOException { ObjectMapper objectMapper = new ObjectMapper(); SimpleModule module = new SimpleModule(); module.addSerializer(Color.class, new ColorSerializer()); module.addDeserializer(Color.class, new ColorDeserializer()); objectMapper.registerModule(module); Color testColor = new Color(1, 2, 3, 4); String json = objectMapper.writeValueAsString(testColor); Color backToObject = objectMapper.readValue(json, Color.class); if (!testColor.equals(backToObject)) { throw new AssertionError("round trip failed"); } } }个对象的示例：

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无法使用jackson反序列化器反序列化java.awt.color

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