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Spice up your java: Automatic Resource Management, automatic generation of getters, setters, equals, hashCode and toString, and more!

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/*
 * Copyright (C) 2009-2017 The Project Lombok Authors.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package lombok;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Ensures the variable declaration that you annotate will be cleaned up by calling its close method, regardless
 * of what happens. Implemented by wrapping all statements following the local variable declaration to the
 * end of your scope into a try block that, as a finally action, closes the resource.
 * 
 * Complete documentation is found at the project lombok features page for @Cleanup.
 * 

 * Example:
 * 
 * public void copyFile(String in, String out) throws IOException {
 *     @Cleanup FileInputStream inStream = new FileInputStream(in);
 *     @Cleanup FileOutputStream outStream = new FileOutputStream(out);
 *     byte[] b = new byte[65536];
 *     while (true) {
 *         int r = inStream.read(b);
 *         if (r == -1) break;
 *         outStream.write(b, 0, r);
 *     }
 * }
 * 
 * 
 * Will generate:
 *  * public void copyFile(String in, String out) throws IOException {
 *     @Cleanup FileInputStream inStream = new FileInputStream(in);
 *     try {
 *         @Cleanup FileOutputStream outStream = new FileOutputStream(out);
 *         try {
 *             byte[] b = new byte[65536];
 *             while (true) {
 *                 int r = inStream.read(b);
 *                 if (r == -1) break;
 *                 outStream.write(b, 0, r);
 *             }
 *         } finally {
 *             if (outStream != null) outStream.close();
 *         }
 *     } finally {
 *         if (inStream != null) inStream.close();
 *     }
 * }
 * 
 */
@Target(ElementType.LOCAL_VARIABLE)
@Retention(RetentionPolicy.SOURCE)
public @interface Cleanup {
	/** @return The name of the method that cleans up the resource. By default, 'close'. The method must not have any parameters. */
	String value() default "close";
}