1 /*

     2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     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.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 import java.io.IOException;

    25 import java.io.PrintStream;

    26 import java.net.http.HttpClient;

    27 import java.net.http.HttpRequest;

    28 import java.net.http.HttpResponse;

    29 import java.net.http.HttpResponse.BodyHandler;

    30 import java.util.Collections;

    31 import java.util.List;

    32 import java.util.concurrent.CopyOnWriteArrayList;

    33 import java.util.concurrent.Flow;

    34 import java.util.regex.Pattern;

    35 

    36 /*

    37  * THE CONTENTS OF THIS FILE HAVE TO BE IN SYNC WITH THE EXAMPLES USED IN THE

    38  * JAVADOC.

    39  *

    40  * @test

    41  * @compile JavadocExamples.java

    42  */

    43 public class JavadocExamples {

    44     HttpRequest request = null;

    45     HttpClient client = null;

    46     Pattern p = null;

    47 

    48     /**

    49      * @apiNote This method can be used as an adapter between a {@code

    50      * BodySubscriber} and a text based {@code Flow.Subscriber} that parses

    51      * text line by line.

    52      *

    53      * <p> For example:

    54      * <pre> {@code  // A PrintSubscriber that implements Flow.Subscriber<String>

    55      *  // and print lines received by onNext() on System.out

    56      *  PrintSubscriber subscriber = new PrintSubscriber(System.out);

    57      *  client.sendAsync(request, BodyHandler.fromLineSubscriber(subscriber))

    58      *      .thenApply(HttpResponse::statusCode)

    59      *      .thenAccept((status) -> {

    60      *          if (status != 200) {

    61      *              System.err.printf("ERROR: %d status received%n", status);

    62      *          }

    63      *      }); }</pre>

    64      */

    65     void fromLineSubscriber1() {

    66          // A PrintSubscriber that implements Flow.Subscriber<String>

    67          // and print lines received by onNext() on System.out

    68          PrintSubscriber subscriber = new PrintSubscriber(System.out);

    69          client.sendAsync(request, BodyHandler.fromLineSubscriber(subscriber))

    70                  .thenApply(HttpResponse::statusCode)

    71                  .thenAccept((status) -> {

    72                      if (status != 200) {

    73                          System.err.printf("ERROR: %d status received%n", status);

    74                      }

    75                  });

    76     }

    77 

    78     /**

    79      * @apiNote This method can be used as an adapter between a {@code

    80      * BodySubscriber} and a text based {@code Flow.Subscriber} that parses

    81      * text line by line.

    82      *

    83      * <p> For example:

    84      * <pre> {@code  // A LineParserSubscriber that implements Flow.Subscriber<String>

    85      *  // and accumulates lines that match a particular pattern

    86      *  Pattern pattern = ...;

    87      *  LineParserSubscriber subscriber = new LineParserSubscriber(pattern);

    88      *  HttpResponse<List<String>> response = client.send(request,

    89      *  BodyHandler.fromLineSubscriber(subscriber, s -> s.getMatchingLines(), "\n"));

    90      *  if (response.statusCode() != 200) {

    91      *      System.err.printf("ERROR: %d status received%n", response.statusCode());

    92      *  } }</pre>

    93      *

    94      */

    95     void fromLineSubscriber2() throws IOException, InterruptedException {

    96         // A LineParserSubscriber that implements Flow.Subscriber<String>

    97         // and accumulates lines that match a particular pattern

    98         Pattern pattern = p;

    99         LineParserSubscriber subscriber = new LineParserSubscriber(pattern);

   100         HttpResponse<List<String>> response = client.send(request,

   101                 BodyHandler.fromLineSubscriber(subscriber, s -> s.getMatchingLines(), "\n"));

   102         if (response.statusCode() != 200) {

   103             System.err.printf("ERROR: %d status received%n", response.statusCode());

   104         }

   105     }

   106 

   107     static final class PrintSubscriber implements Flow.Subscriber<String> {

   108         final PrintStream out;

   109         PrintSubscriber(PrintStream out) {

   110             this.out = out;

   111         }

   112         @Override

   113         public void onSubscribe(Flow.Subscription subscription) {

   114             subscription.request(Long.MAX_VALUE);

   115         }

   116         @Override

   117         public void onNext(String item) {

   118             out.println(item);

   119         }

   120 

   121         @Override

   122         public void onError(Throwable throwable) {

   123             throwable.printStackTrace();

   124         }

   125         @Override

   126         public void onComplete() {

   127         }

   128     }

   129 

   130     static final class LineParserSubscriber implements Flow.Subscriber<String> {

   131         final Pattern pattern;

   132         final CopyOnWriteArrayList<String> matches = new CopyOnWriteArrayList<>();

   133         LineParserSubscriber(Pattern pattern) {

   134             this.pattern = pattern;

   135         }

   136         @Override

   137         public void onSubscribe(Flow.Subscription subscription) {

   138             subscription.request(Long.MAX_VALUE);

   139         }

   140         @Override

   141         public void onNext(String item) {

   142             if (pattern.matcher(item).matches()) {

   143                 matches.add(item);

   144             }

   145         }

   146         @Override

   147         public void onError(Throwable throwable) {

   148             throwable.printStackTrace();

   149         }

   150         @Override

   151         public void onComplete() {

   152         }

   153 

   154         public List<String> getMatchingLines() {

   155             return Collections.unmodifiableList(matches);

   156         }

   157     }

   158 

   159 }