1 /* 2 * Copyright (C) 2008 The Guava Authors 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 17 package com.google.common.testing; 18 19 import com.google.common.annotations.Beta; 20 21 import java.util.ArrayList; 22 import java.util.Collections; 23 import java.util.List; 24 import java.util.logging.Handler; 25 import java.util.logging.LogRecord; 26 27 import javax.annotation.Nullable; 28 29 /** 30 * Tests may use this to intercept messages that are logged by the code under 31 * test. Example: 32 * <pre> 33 * TestLogHandler handler; 34 * 35 * protected void setUp() throws Exception { 36 * super.setUp(); 37 * handler = new TestLogHandler(); 38 * SomeClass.logger.addHandler(handler); 39 * addTearDown(new TearDown() { 40 * public void tearDown() throws Exception { 41 * SomeClass.logger.removeHandler(handler); 42 * } 43 * }); 44 * } 45 * 46 * public void test() { 47 * SomeClass.foo(); 48 * LogRecord firstRecord = handler.getStoredLogRecords().get(0); 49 * assertEquals("some message", firstRecord.getMessage()); 50 * } 51 * </pre> 52 * 53 * @author Kevin Bourrillion 54 * @since 10.0 55 */ 56 @Beta 57 public class TestLogHandler extends Handler { 58 /** We will keep a private list of all logged records */ 59 private final List<LogRecord> list = 60 Collections.synchronizedList(new ArrayList<LogRecord>()); 61 62 /** 63 * Adds the most recently logged record to our list. 64 */ 65 @Override publish(@ullable LogRecord record)66 public void publish(@Nullable LogRecord record) { 67 list.add(record); 68 } 69 70 @Override flush()71 public void flush() {} 72 73 @Override close()74 public void close() {} 75 clear()76 public void clear() { 77 list.clear(); 78 } 79 80 /** 81 * Fetch the list of logged records 82 * @return unmodifiable LogRecord list of all logged records 83 */ getStoredLogRecords()84 public List<LogRecord> getStoredLogRecords() { 85 List<LogRecord> result = new ArrayList<LogRecord>(list); 86 return Collections.unmodifiableList(result); 87 } 88 } 89