1 /* 2 * Copyright 2008 Google LLC 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.google.auto.service.processor; 17 18 import static java.nio.charset.StandardCharsets.UTF_8; 19 20 import java.io.BufferedReader; 21 import java.io.BufferedWriter; 22 import java.io.IOException; 23 import java.io.InputStream; 24 import java.io.InputStreamReader; 25 import java.io.OutputStream; 26 import java.io.OutputStreamWriter; 27 import java.util.Collection; 28 import java.util.HashSet; 29 import java.util.Set; 30 31 /** 32 * A helper class for reading and writing Services files. 33 */ 34 final class ServicesFiles { 35 public static final String SERVICES_PATH = "META-INF/services"; 36 ServicesFiles()37 private ServicesFiles() {} 38 39 /** 40 * Returns an absolute path to a service file given the class 41 * name of the service. 42 * 43 * @param serviceName not {@code null} 44 * @return SERVICES_PATH + serviceName 45 */ getPath(String serviceName)46 static String getPath(String serviceName) { 47 return SERVICES_PATH + "/" + serviceName; 48 } 49 50 /** 51 * Reads the set of service classes from a service file. 52 * 53 * @param input not {@code null}. Closed after use. 54 * @return a not {@code null Set} of service class names. 55 * @throws IOException 56 */ readServiceFile(InputStream input)57 static Set<String> readServiceFile(InputStream input) throws IOException { 58 HashSet<String> serviceClasses = new HashSet<String>(); 59 try (BufferedReader reader = new BufferedReader(new InputStreamReader(input, UTF_8))) { 60 String line; 61 while ((line = reader.readLine()) != null) { 62 int commentStart = line.indexOf('#'); 63 if (commentStart >= 0) { 64 line = line.substring(0, commentStart); 65 } 66 line = line.trim(); 67 if (!line.isEmpty()) { 68 serviceClasses.add(line); 69 } 70 } 71 return serviceClasses; 72 } 73 } 74 75 /** 76 * Writes the set of service class names to a service file. 77 * 78 * @param output not {@code null}. Not closed after use. 79 * @param services a not {@code null Collection} of service class names. 80 * @throws IOException 81 */ writeServiceFile(Collection<String> services, OutputStream output)82 static void writeServiceFile(Collection<String> services, OutputStream output) 83 throws IOException { 84 BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(output, UTF_8)); 85 for (String service : services) { 86 writer.write(service); 87 writer.newLine(); 88 } 89 writer.flush(); 90 } 91 } 92