1 // Copyright 2020 Google LLC 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package com.google.api.generator.gapic.utils; 16 17 import com.google.api.generator.engine.lexicon.Keyword; 18 import com.google.common.base.CaseFormat; 19 import com.google.common.base.Strings; 20 import java.util.stream.IntStream; 21 22 public class JavaStyle { 23 private static final String UNDERSCORE = "_"; 24 toLowerCamelCase(String s)25 public static String toLowerCamelCase(String s) { 26 if (Strings.isNullOrEmpty(s)) { 27 return s; 28 } 29 30 s = s.replace('-', '_'); 31 32 if (s.indexOf(UNDERSCORE) >= 0) { 33 s = CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.UPPER_CAMEL, s); 34 } 35 36 String name = 37 capitalizeLettersAfterDigits( 38 String.format("%s%s", s.substring(0, 1).toLowerCase(), s.substring(1))); 39 40 // Some APIs use legit java keywords as method names. Both protobuf and gGRPC add an underscore 41 // in generated stubs to resolve name conflict, so we need to do the same. 42 return Keyword.escapeKeyword(name); 43 } 44 toUpperCamelCase(String s)45 public static String toUpperCamelCase(String s) { 46 if (Strings.isNullOrEmpty(s)) { 47 return s; 48 } 49 50 s = s.replace('-', '_'); 51 52 if (s.indexOf(UNDERSCORE) >= 0) { 53 s = CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.UPPER_CAMEL, s); 54 } 55 return capitalizeLettersAfterDigits( 56 String.format("%s%s", s.substring(0, 1).toUpperCase(), s.substring(1))); 57 } 58 toUpperSnakeCase(String s)59 public static String toUpperSnakeCase(String s) { 60 String result = CaseFormat.UPPER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, toUpperCamelCase(s)); 61 return result; 62 } 63 capitalizeLettersAfterDigits(String s)64 private static String capitalizeLettersAfterDigits(String s) { 65 return IntStream.range(0, s.length()) 66 .collect( 67 StringBuilder::new, 68 (sb, i) -> 69 sb.append( 70 i > 0 && Character.isDigit(s.charAt(i - 1)) 71 ? Character.toUpperCase(s.charAt(i)) 72 : s.charAt(i)), 73 StringBuilder::append) 74 .toString(); 75 } 76 } 77