| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package java.lang; |
| |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| |
| /** |
| * Represents an external process. Enables writing to, reading from, destroying, |
| * and waiting for the external process, as well as querying its exit value. Use |
| * {@link ProcessBuilder} to create processes. |
| * |
| * <p>The child process writes its output to two streams, {@code out} and |
| * {@code err}. These streams should be read by the parent process using {@link |
| * #getInputStream()} and {@link #getErrorStream()} respectively. If these |
| * streams are not read, the target process may block while it awaits buffer |
| * space. It isn't sufficient to read the streams in sequence; to avoid blocking |
| * each of the two streams must have its own reader thread. If you are not |
| * interested in differentiating the out and err streams, use {@link |
| * ProcessBuilder#redirectErrorStream(boolean) redirectErrorStream(true)} to |
| * merge the two streams. This simplifies your reading code and makes it easier |
| * to avoid blocking the target process. |
| * |
| * <p>Running processes hold resources. When a process is no longer used, the |
| * process should be closed by calling {@link #destroy}. This will kill the |
| * process and release the resources that it holds. |
| * |
| * <p>For example, to run {@code /system/bin/ping} to ping {@code android.com}: |
| * <pre> {@code |
| * Process process = new ProcessBuilder() |
| * .command("/system/bin/ping", "android.com") |
| * .redirectErrorStream(true) |
| * .start(); |
| * try { |
| * InputStream in = process.getInputStream(); |
| * OutputStream out = process.getOutputStream(); |
| * |
| * readStream(in); |
| * |
| * } finally { |
| * process.destroy(); |
| * } |
| * }</pre> |
| */ |
| public abstract class Process { |
| |
| /** |
| * Terminates this process and closes any associated streams. |
| */ |
| public abstract void destroy(); |
| |
| /** |
| * Returns the exit value of the native process represented by this object. |
| * It is available only when the native process has terminated. |
| * |
| * @return the exit value of this process. |
| * @throws IllegalThreadStateException |
| * if this process has not terminated. |
| */ |
| public abstract int exitValue(); |
| |
| /** |
| * Returns an input stream that is connected to the error stream |
| * <em>(stderr)</em> of the native process represented by this object. |
| * |
| * @return the input stream to read from the error stream associated with |
| * the native process. |
| */ |
| public abstract InputStream getErrorStream(); |
| |
| /** |
| * Returns an input stream that is connected to the standard output stream |
| * <em>(stdout)</em> of the native process represented by this object. |
| * |
| * @return the input stream to read from the output stream associated with |
| * the native process. |
| */ |
| public abstract InputStream getInputStream(); |
| |
| /** |
| * Returns an output stream that is connected to the standard input stream |
| * <em>(stdin)</em> of the native process represented by this object. |
| * |
| * @return the output stream to write to the input stream associated with |
| * the native process. |
| */ |
| public abstract OutputStream getOutputStream(); |
| |
| /** |
| * Causes the calling thread to wait for the native process associated with |
| * this object to finish executing. |
| * |
| * @return the exit value of the native process being waited on. |
| * @throws InterruptedException |
| * if the calling thread is interrupted. |
| */ |
| public abstract int waitFor() throws InterruptedException; |
| } |