enhance the java doc of dubbo-common module. (#5578)

dubbo-common/src/main/java/org/apache/dubbo/common/utils/MethodUtils.java

@@ -19,8 +19,22 @@ package org.apache.dubbo.common.utils;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 
+/**
+ * Miscellaneous method utility methods.
+ * Mainly for internal use within the framework.
+ *
+ * @author LiZhenNet
+ * @since 2.7.2
+ */
 public class MethodUtils {
 
+    /**
+     * Return {@code true} if the provided method is a set method.
+     * Otherwise, return {@code false}.
+     *
+     * @param method the method to check
+     * @return whether the given method is setter method
+     */
     public static boolean isSetter(Method method) {
         return method.getName().startsWith("set")
                 && !"set".equals(method.getName())
@@ -29,6 +43,13 @@ public class MethodUtils {
                 && ClassUtils.isPrimitive(method.getParameterTypes()[0]);
     }
 
+    /**
+     * Return {@code true} if the provided method is a get method.
+     * Otherwise, return {@code false}.
+     *
+     * @param method the method to check
+     * @return whether the given method is getter method
+     */
     public static boolean isGetter(Method method) {
         String name = method.getName();
         return (name.startsWith("get") || name.startsWith("is"))
@@ -39,6 +60,13 @@ public class MethodUtils {
                 && ClassUtils.isPrimitive(method.getReturnType());
     }
 
+    /**
+     * Return {@code true} If this method is a meta method.
+     * Otherwise, return {@code false}.
+     *
+     * @param method the method to check
+     * @return whether the given method is meta method
+     */
     public static boolean isMetaMethod(Method method) {
         String name = method.getName();
         if (!(name.startsWith("get") || name.startsWith("is"))) {
@@ -62,6 +90,14 @@ public class MethodUtils {
         return true;
     }
 
+    /**
+     * Check if the method is a deprecated method. The standard is whether the {@link java.lang.Deprecated} annotation is declared on the class.
+     * Return {@code true} if this annotation is present.
+     * Otherwise, return {@code false}.
+     *
+     * @param method the method to check
+     * @return whether the given method is deprecated method
+     */
     public static boolean isDeprecated(Method method) {
         return method.getAnnotation(Deprecated.class) != null;
     }