Nullable.java

/*
 * Copyright 2010-2013 JetBrains s.r.o.
 *
 * 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 org.jetbrains.annotations;

import java.lang.annotation.*;

/**
 * An element annotated with Nullable claims <code>null</code> value is perfectly <em>valid</em>
 * to return (for methods), pass to (parameters) and hold (local variables and fields).
 * Apart from documentation purposes this annotation is intended to be used by static analysis tools
 * to validate against probable runtime errors and element contract violations.
 */
@Documented
@Retention(RetentionPolicy.CLASS)
@Target({ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER, ElementType.LOCAL_VARIABLE})
public @interface Nullable {
    String value() default "";
}