feat:优雅判空

hutool-core/src/test/java/cn/hutool/core/bean/OptionalBeanTest.java

@@ -0,0 +1,49 @@
+package cn.hutool.core.bean;
+
+import org.junit.Assert;
+import lombok.Data;
+import org.junit.Test;
+
+public class OptionalBeanTest {
+
+    @Test
+    public void OptionalBeanTest() {
+        User user = new User();
+        user.setName("hello");
+        String value1 = OptionalBean.ofNullable(user)
+                .getBean(User::getSchool)
+                .getBean(User.School::getAddress).get();
+        Assert.assertEquals(value1, null);
+
+        boolean present = OptionalBean.ofNullable(user)
+                .getBean(User::getSchool)
+                .getBean(User.School::getAddress).isPresent();
+        Assert.assertFalse(present);
+
+        String value2 = OptionalBean.ofNullable(user)
+                .getBean(User::getSchool)
+                .getBean(User.School::getAddress).orElse("没得地址");
+        Assert.assertEquals(value2, "没得地址");
+        try {
+            OptionalBean.ofNullable(user)
+                    .getBean(User::getSchool)
+                    .getBean(User.School::getAddress).orElseThrow(() -> new RuntimeException("空指针了"));
+        } catch (Exception e) {
+            Assert.assertEquals(e.getMessage(), "空指针了");
+        }
+    }
+
+
+    @Data
+    public class User {
+        private String name;
+        private String gender;
+        private School school;
+        @Data
+        public class School {
+            private String name;
+            private String address;
+        }
+    }
+
+}