Merge branch 'dev/ConcurrentReferenceHashMap'

Author: oldratlee

ttl-core/src/main/java/com/alibaba/ttl3/internal/util/Assert.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2002-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.alibaba.ttl3.internal.util;
+
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// This source code file is copied from spring v5.3.24:
+//
+// https://github.com/spring-projects/spring-framework/blob/v5.3.24/spring-core/src/main/java/org/springframework/util/Assert.java
+//
+// with adoption:
+// - remove unused elements
+// - adjust visible modifier and code format
+//
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+import edu.umd.cs.findbugs.annotations.Nullable;
+
+/**
+ * Assertion utility class that assists in validating arguments.
+ *
+ * <p>Useful for identifying programmer errors early and clearly at runtime.
+ *
+ * <p>For example, if the contract of a public method states it does not
+ * allow {@code null} arguments, {@code Assert} can be used to validate that
+ * contract. Doing this clearly indicates a contract violation when it
+ * occurs and protects the class's invariants.
+ *
+ * <p>Typically used to validate method arguments rather than configuration
+ * properties, to check for cases that are usually programmer errors rather
+ * than configuration errors. In contrast to configuration initialization
+ * code, there is usually no point in falling back to defaults in such methods.
+ *
+ * <p>This class is similar to JUnit's assertion library. If an argument value is
+ * deemed invalid, an {@link IllegalArgumentException} is thrown (typically).
+ * For example:
+ *
+ * <pre class="code">
+ * Assert.notNull(clazz, "The class must not be null");
+ * Assert.isTrue(i &gt; 0, "The value must be greater than zero");</pre>
+ *
+ * <p>Mainly for internal use within the framework; for a more comprehensive suite
+ * of assertion utilities consider {@code org.apache.commons.lang3.Validate} from
+ * <a href="https://commons.apache.org/proper/commons-lang/">Apache Commons Lang</a>,
+ * Google Guava's
+ * <a href="https://github.com/google/guava/wiki/PreconditionsExplained">Preconditions</a>,
+ * or similar third-party libraries.
+ *
+ * @author Keith Donald
+ * @author Juergen Hoeller
+ * @author Sam Brannen
+ * @author Colin Sampaleanu
+ * @author Rob Harrop
+ */
+final class Assert {
+
+    /**
+     * Assert a boolean expression, throwing an {@code IllegalStateException}
+     * if the expression evaluates to {@code false}.
+     * <p>Call {@link #isTrue} if you wish to throw an {@code IllegalArgumentException}
+     * on an assertion failure.
+     * <pre class="code">Assert.state(id == null, "The id property must not already be initialized");</pre>
+     *
+     * @param expression a boolean expression
+     * @param message    the exception message to use if the assertion fails
+     * @throws IllegalStateException if {@code expression} is {@code false}
+     */
+    public static void state(boolean expression, String message) {
+        if (!expression) {
+            throw new IllegalStateException(message);
+        }
+    }
+
+    /**
+     * Assert a boolean expression, throwing an {@code IllegalArgumentException}
+     * if the expression evaluates to {@code false}.
+     * <pre class="code">Assert.isTrue(i &gt; 0, "The value must be greater than zero");</pre>
+     *
+     * @param expression a boolean expression
+     * @param message    the exception message to use if the assertion fails
+     * @throws IllegalArgumentException if {@code expression} is {@code false}
+     */
+    public static void isTrue(boolean expression, String message) {
+        if (!expression) {
+            throw new IllegalArgumentException(message);
+        }
+    }
+
+    /**
+     * Assert that an object is not {@code null}.
+     * <pre class="code">Assert.notNull(clazz, "The class must not be null");</pre>
+     *
+     * @param object  the object to check
+     * @param message the exception message to use if the assertion fails
+     * @throws IllegalArgumentException if the object is {@code null}
+     */
+    public static void notNull(@Nullable Object object, String message) {
+        if (object == null) {
+            throw new IllegalArgumentException(message);
+        }
+    }
+
+}