LombokReflections

LombokReflections.java

import java.beans.Introspector;
import java.io.Serializable;
import java.lang.invoke.SerializedLambda;
import java.lang.reflect.Method;
import java.util.function.Function;
import java.util.regex.Pattern;

/**
 * Lombok反射工具
 *
 * @author tangjialin on 2018-11-27.
 */
public class LombokReflections {
    private static final Pattern GET_SET_PATTERN = Pattern.compile("^(g|s)et[A-Z][\\w\\$]*");
    private static final Pattern IS_PATTERN = Pattern.compile("^is[A-Z][\\w\\$]*");

    private LombokReflections() {
    }

    /**
     * 从Lombok函数中获取方法名称反解字段名称
     *
     * @param fn  Lombok函数
     * @param <T> 入参类型
     * @param <R> 结果的参数类型
     * @return 返回字段名称
     */
    public static <T, R> String fnToFieldName(LombokFn<T, R> fn) {
        try {
            Method method = fn.getClass().getDeclaredMethod("writeReplace");
            method.setAccessible(Boolean.TRUE);
            SerializedLambda serializedLambda = (SerializedLambda) method.invoke(fn);
            String methodName = serializedLambda.getImplMethodName();
            if (GET_SET_PATTERN.matcher(methodName).matches()) {
                methodName = methodName.substring(3);
            } else if (IS_PATTERN.matcher(methodName).matches()) {
                methodName = methodName.substring(2);
            }
            return Introspector.decapitalize(methodName);
        } catch (ReflectiveOperationException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * FunctionalInterface
     *
     * @author tangjialin on 2018-11-27.
     */
    public interface LombokFn<T, R> extends Function<T, R>, Serializable {
    }
}

LombokReflectionsTest.java

import org.junit.Assert;
import org.junit.Test;

public class LombokReflectionsTest {

    @Test
    public void fnToFieldName() {
        // 这个方法编译不通过,必须要有返回值的
        // LombokReflections.fnToFieldName(DemoBean::isnxx);
        Assert.assertEquals("nxx", LombokReflections.fnToFieldName(DemoBean::isNxx));
        Assert.assertEquals("n_na$", LombokReflections.fnToFieldName(DemoBean::getN_na$));
        Assert.assertEquals("name", LombokReflections.fnToFieldName(DemoBean::setName));
        Assert.assertEquals("name", LombokReflections.fnToFieldName(DemoBean::name));
        Assert.assertEquals("age", LombokReflections.fnToFieldName(DemoBean::Age));
    }

    public static class DemoBean {
        public void isnxx() {
        }

        public String isNxx() {
            return null;
        }


        public String getN_na$() {
            return null;
        }

        public DemoBean setName() {
            return this;
        }

        public String name() {
            return null;
        }

        public String Age() {
            return null;
        }
    }
}