组装Mybatis Plus 查询条件添加排除条件

src/main/java/com/zhgd/xmgl/util/ReflectionUtil.java

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+package com.zhgd.xmgl.util;
+
+import org.springframework.util.ClassUtils;
+import org.springframework.util.ReflectionUtils;
+
+import java.beans.Introspector;
+import java.lang.invoke.SerializedLambda;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * 方法引用获取属性名工具类
+ */
+public class ReflectionUtil {
+
+    private static Map<SerializableFunction<?, ?>, Field> cache = new ConcurrentHashMap<>();
+
+    /**
+     * 方法引用获取属性名
+     *
+     * @param function
+     * @param <T>
+     * @param <R>
+     * @return
+     */
+    public static <T, R> String getFieldName(SerializableFunction<T, R> function) {
+        Field field = ReflectionUtil.getField(function);
+        return field.getName();
+    }
+
+    public static <T, R> Field getField(SerializableFunction<T, R> function) {
+        return cache.computeIfAbsent(function, ReflectionUtil::findField);
+    }
+
+    public static <T, R> Field findField(SerializableFunction<T, R> function) {
+        Field field = null;
+        String fieldName = null;
+        try {
+            // 第1步 获取SerializedLambda
+            Method method = function.getClass().getDeclaredMethod("writeReplace");
+            method.setAccessible(Boolean.TRUE);
+            SerializedLambda serializedLambda = (SerializedLambda) method.invoke(function);
+            // 第2步 implMethodName 即为Field对应的Getter方法名
+            String implMethodName = serializedLambda.getImplMethodName();
+            if (implMethodName.startsWith("get") && implMethodName.length() > 3) {
+                fieldName = Introspector.decapitalize(implMethodName.substring(3));
+
+            } else if (implMethodName.startsWith("is") && implMethodName.length() > 2) {
+                fieldName = Introspector.decapitalize(implMethodName.substring(2));
+            } else if (implMethodName.startsWith("lambda$")) {
+                throw new IllegalArgumentException("SerializableFunction不能传递lambda表达式,只能使用方法引用");
+
+            } else {
+                throw new IllegalArgumentException(implMethodName + "不是Getter方法引用");
+            }
+            // 第3步 获取的Class是字符串，并且包名是“/”分割，需要替换成“.”，才能获取到对应的Class对象
+            String declaredClass = serializedLambda.getImplClass().replace("/", ".");
+            Class<?> aClass = Class.forName(declaredClass, false, ClassUtils.getDefaultClassLoader());
+
+            // 第4步  Spring 中的反射工具类获取Class中定义的Field
+            field = ReflectionUtils.findField(aClass, fieldName);
+
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        // 第5步 如果没有找到对应的字段应该抛出异常
+        if (field != null) {
+            return field;
+        }
+        throw new NoSuchFieldError(fieldName);
+    }
+}

src/main/java/com/zhgd/xmgl/util/SerializableFunction.java

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+package com.zhgd.xmgl.util;
+
+import java.io.Serializable;
+import java.util.function.Function;
+
+@FunctionalInterface
+public interface SerializableFunction<T, R> extends Function<T, R>, Serializable {
+
+}