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src/java.base/share/classes/java/util/function/Consumer.java

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   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package java.util.function;
  26 
  27 import java.util.Objects;
  28 
  29 /**
  30  * Represents an operation that accepts a single input argument and returns no
  31  * result. Unlike most other functional interfaces, {@code Consumer} is expected
  32  * to operate via side-effects.
  33  *
  34  * <p>This is a <a href="package-summary.html">functional interface</a>
  35  * whose functional method is {@link #accept(Object)}.
  36  *
  37  * @param <T> the type of the input to the operation
  38  *
  39  * @since 1.8
  40  */
  41 @FunctionalInterface
  42 public interface Consumer<T> {
  43 
  44     /**
  45      * Performs this operation on the given argument.
  46      *
  47      * @param t the input argument
  48      */
  49     void accept(T t);
  50 
  51     /**
  52      * Returns a composed {@code Consumer} that performs, in sequence, this
  53      * operation followed by the {@code after} operation. If performing either
  54      * operation throws an exception, it is relayed to the caller of the
  55      * composed operation.  If performing this operation throws an exception,
  56      * the {@code after} operation will not be performed.
  57      *
  58      * @param after the operation to perform after this operation
  59      * @return a composed {@code Consumer} that performs in sequence this
  60      * operation followed by the {@code after} operation
  61      * @throws NullPointerException if {@code after} is null
  62      */
  63     default Consumer<T> andThen(Consumer<? super T> after) {
  64         Objects.requireNonNull(after);
  65         return (T t) -> { accept(t); after.accept(t); };
  66     }
  67 }


   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package javany.util.function;
  26 
  27 import java.util.Objects;
  28 
  29 /**
  30  * Represents an operation that accepts a single input argument and returns no
  31  * result. Unlike most other functional interfaces, {@code Consumer} is expected
  32  * to operate via side-effects.
  33  *
  34  * <p>This is a <a href="package-summary.html">functional interface</a>
  35  * whose functional method is {@link #accept(Object)}.
  36  *
  37  * @param <T> the type of the input to the operation
  38  *
  39  * @since 1.8
  40  */
  41 @FunctionalInterface
  42 public interface Consumer<any T> {
  43 
  44     /**
  45      * Performs this operation on the given argument.
  46      *
  47      * @param t the input argument
  48      */
  49     void accept(T t);
  50 
  51     /**
  52      * Returns a composed {@code Consumer} that performs, in sequence, this
  53      * operation followed by the {@code after} operation. If performing either
  54      * operation throws an exception, it is relayed to the caller of the
  55      * composed operation.  If performing this operation throws an exception,
  56      * the {@code after} operation will not be performed.
  57      *
  58      * @param after the operation to perform after this operation
  59      * @return a composed {@code Consumer} that performs in sequence this
  60      * operation followed by the {@code after} operation
  61      * @throws NullPointerException if {@code after} is null
  62      */
  63     default Consumer<T> andThen(Consumer<T> after) {
  64         Objects.requireNonNull(after);
  65         return (T t) -> { accept(t); after.accept(t); };
  66     }
  67 }
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