1 package org.apache.maven.plugin.surefire.booterclient.lazytestprovider; 2 3 /* 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 */ 21 22 import org.apache.maven.surefire.api.booter.Command; 23 24 import java.io.IOException; 25 26 /** 27 * Reader stream sends commands to forked jvm std-{@link java.io.InputStream input-stream}. 28 * 29 * @author <a href="mailto:tibordigana@apache.org">Tibor Digana (tibor17)</a> 30 * @since 2.19 31 * @see Command 32 */ 33 public abstract class DefaultCommandReader 34 extends AbstractCommandReader 35 { 36 /** 37 * Opposite to {@link #isClosed()}. 38 * @return {@code true} if not closed 39 */ 40 protected boolean canContinue() 41 { 42 return !isClosed(); 43 } 44 45 /** 46 * Possibly waiting for next command (see {@link #nextCommand()}) unless the stream is atomically 47 * closed (see {@link #isClosed()} returns {@code true}) before this method has returned. 48 * 49 * @throws IOException stream error while waiting for notification regarding next test required by forked jvm 50 */ 51 protected void beforeNextCommand() 52 throws IOException 53 { 54 } 55 56 protected abstract Command nextCommand(); 57 58 /** 59 * Used by single thread in StreamFeeder class. 60 * 61 * @return {@inheritDoc} 62 * @throws IOException {@inheritDoc} 63 */ 64 @Override 65 public Command readNextCommand() 66 throws IOException 67 { 68 if ( isClosed() ) 69 { 70 return null; 71 } 72 73 if ( !canContinue() ) 74 { 75 close(); 76 return null; 77 } 78 79 beforeNextCommand(); 80 81 if ( isClosed() ) 82 { 83 return null; 84 } 85 86 return nextCommand(); 87 } 88 }