1 /* 2 * Copyright (C) 2024 The Android Open Source Project 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.android.adservices.shared.testing.util; 17 18 import java.io.ByteArrayOutputStream; 19 import java.io.IOException; 20 import java.io.PrintStream; 21 import java.io.PrintWriter; 22 import java.io.StringWriter; 23 import java.util.Objects; 24 25 /** Helper class for IO-related stuff. */ 26 public final class IoHelper { 27 28 /** 29 * Converts the contents of a {@link PrintWriter} to a string. 30 * 31 * <p>Typically used to test {@code dump()} methods. 32 */ printWriterToString(ThrowingConsumer<PrintWriter, IOException> consumer)33 public static String printWriterToString(ThrowingConsumer<PrintWriter, IOException> consumer) 34 throws IOException { 35 Objects.requireNonNull(consumer, "consumer cannot be null"); 36 try (StringWriter sw = new StringWriter()) { 37 PrintWriter pw = new PrintWriter(sw); 38 consumer.accept(pw); 39 pw.flush(); 40 return sw.toString(); 41 } 42 } 43 44 /** 45 * Converts the contents of a {@link PrintStream} to a string. 46 * 47 * <p>Typically used to test {@code dump()} methods. 48 */ printStreamToString(ThrowingConsumer<PrintStream, IOException> consumer)49 public static String printStreamToString(ThrowingConsumer<PrintStream, IOException> consumer) 50 throws IOException { 51 Objects.requireNonNull(consumer, "consumer cannot be null"); 52 try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) { 53 PrintStream ps = new PrintStream(baos, /* autoFlush= */ true); 54 consumer.accept(ps); 55 return baos.toString(); 56 } 57 } 58 IoHelper()59 private IoHelper() { 60 throw new UnsupportedOperationException("Provides only static methods"); 61 } 62 } 63