1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package java.lang; 19 20 import java.io.InputStream; 21 import java.io.OutputStream; 22 23 /** 24 * Represents an external process. Enables writing to, reading from, destroying, 25 * and waiting for the external process, as well as querying its exit value. 26 * 27 * @see Runtime#exec 28 * @see ProcessBuilder#start() 29 */ 30 public abstract class Process { 31 32 /** 33 * Terminates this process and closes any associated streams. 34 */ destroy()35 abstract public void destroy(); 36 37 /** 38 * Returns the exit value of the native process represented by this object. 39 * It is available only when the native process has terminated. 40 * 41 * @return the exit value of this process. 42 * @throws IllegalThreadStateException 43 * if this process has not terminated. 44 */ exitValue()45 abstract public int exitValue(); 46 47 /** 48 * Returns an input stream that is connected to the error stream 49 * <em>(stderr)</em> of the native process represented by this object. 50 * 51 * @return the input stream to read from the error stream associated with 52 * the native process. 53 */ getErrorStream()54 abstract public InputStream getErrorStream(); 55 56 /** 57 * Returns an input stream that is connected to the standard output stream 58 * <em>(stdout)</em> of the native process represented by this object. 59 * 60 * @return the input stream to read from the output stream associated with 61 * the native process. 62 */ getInputStream()63 abstract public InputStream getInputStream(); 64 65 /** 66 * Returns an output stream that is connected to the standard input stream 67 * <em>(stdin)</em> of the native process represented by this object. 68 * 69 * @return the output stream to write to the input stream associated with 70 * the native process. 71 */ getOutputStream()72 abstract public OutputStream getOutputStream(); 73 74 /** 75 * Causes the calling thread to wait for the native process associated with 76 * this object to finish executing. 77 * 78 * @return the exit value of the native process being waited on. 79 * @throws InterruptedException 80 * if the calling thread is interrupted. 81 */ waitFor()82 abstract public int waitFor() throws InterruptedException; 83 } 84