src/tools/android/java/com/google/devtools/build/android/desugar/testing/junit/DynamicClassLiteral.java

/*
 * Copyright 2019 The Bazel Authors. All rights reserved.
 *
 * 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
 *
 *    http://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.google.devtools.build.android.desugar.testing.junit;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import javax.inject.Qualifier;

/**
 * Identifies injectable class-literal fields with the specified class to load at runtime and assign
 * to the field. An injectable class-literal field may have any access modifier (private,
 * package-private, protected, public). Sample usage:
 *
 * <pre><code>
 * &#064;RunWith(JUnit4.class)
 * public class DesugarRuleTest {
 *
 *   &#064;Rule
 *   public final DesugarRule desugarRule =
 *       DesugarRule.builder(this, MethodHandles.lookup())
 *           .addRuntimeInputs("path/to/my_jar.jar")
 *           .build();
 *   &#064;Inject
 *   &#064;DynamicClassLiteral("my.package.ClassToDesugar")
 *   private Class<?> classToDesugarClass;
 *
 *   // ... Test methods ...
 * }
 * </code></pre>
 */
@Qualifier
@Documented
@Target({ElementType.FIELD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
public @interface DynamicClassLiteral {

  /**
   * The fully-qualified class name of the class to load. The format agrees with {@link
   * Class#getName}.
   */
  String value();

  /** The round during which its associated jar is being used. */
  int round() default 1;
}