@JSONField name属性首字母大小写不敏感

fastjson版本: 1.2.62

测试效果

测试fastjson转换.png

可以看到无论是picUrl1还是PicUrl1, 都能被fastjson转换成对应的picture值.

相关数据

1. 建立实体类

@Data
public class SjtsMotorVehicle implements Serializable {

    private String picture;

    @JSONField(name = "picUrl1")
    public void setPicture(String picture) {
        this.picture = picture;
    }
}

2. 封装相关转换工具

/**
 * 基于fastjson封装json工具
 *
 * @author videomonster
 * @since 1.0.0
 */
public final class JsonUtil {

  /**
     * 将json字符串转为指定类型的实例
     *
     * @param json
     * @param cls
     * @param <T>
     * @return
     */
    public static <T> T parse(String json, Class<T> cls) {
        return JSON.parseObject(json, cls);
    }
}

3. 建立单元测试类, 并造两条测试数据

    private String sjtsPlateData() {
        return "{\n" +
                "  \"picUrl1\": \"http://52.6.127.134:8088/image/3/3/4b81de96ded14e349705dac07a0de0a8/147/11/16db/1251997095/2180\",\n" +
                "}";
    }

    private String sjtsPlateData1() {
        return "{\n" +
                "  \"PicUrl1\": \"http://52.6.127.134:8188/image/3/3/4b81de96ded14e349705dac07a0de0a8/147/11/16db/1251997095/2180\",\n" +
                "}";
    }

转换原理

在com.alibaba.fastjson.JSONObject 类中, 我们可以看到invoke方法, 部分代码如下:

public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        Class<?>[] parameterTypes = method.getParameterTypes();
        if (parameterTypes.length == 1) {

            // other code...
            String name = null;
            JSONField annotation = TypeUtils.getAnnotation(method, JSONField.class);
            if (annotation != null) {
                if (annotation.name().length() != 0) {
                    name = annotation.name();
                }
            }

            if (name == null) {
                name = method.getName();

                if (!name.startsWith("set")) {
                    throw new JSONException("illegal setter");
                }

                name = name.substring(3);
                if (name.length() == 0) {
                    throw new JSONException("illegal setter");
                }
                // 在这里把name属性的首字母转为小写
                name = Character.toLowerCase(name.charAt(0)) + name.substring(1);
            }

            map.put(name, args[0]);
            return null;
        }

       // other code...
    }