1 /*
2 * Copyright 2004-2025 the original author or 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 * https://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.ibatis.common.logging;
17
18 import com.ibatis.common.resources.Resources;
19
20 import java.lang.reflect.Constructor;
21
22 /**
23 * A factory for creating Log objects.
24 */
25 public class LogFactory {
26
27 /** The log constructor. */
28 private static Constructor logConstructor;
29
30 static {
31 tryImplementation("org.apache.commons.logging.LogFactory",
32 "com.ibatis.common.logging.jakarta.JakartaCommonsLoggingImpl");
33 tryImplementation("org.apache.log4j.Logger", "com.ibatis.common.logging.log4j.Log4jImpl");
34 tryImplementation("java.util.logging.Logger", "com.ibatis.common.logging.jdk14.Jdk14LoggingImpl");
35 tryImplementation("java.lang.Object", "com.ibatis.common.logging.nologging.NoLoggingImpl");
36 }
37
38 /**
39 * Try implementation.
40 *
41 * @param testClassName
42 * the test class name
43 * @param implClassName
44 * the impl class name
45 */
46 private static void tryImplementation(String testClassName, String implClassName) {
47 if (logConstructor == null) {
48 try {
49 Resources.classForName(testClassName);
50 Class implClass = Resources.classForName(implClassName);
51 logConstructor = implClass.getConstructor(Class.class);
52 } catch (Throwable t) {
53 }
54 }
55 }
56
57 /**
58 * Gets the log.
59 *
60 * @param aClass
61 * the a class
62 *
63 * @return the log
64 */
65 public static Log getLog(Class aClass) {
66 try {
67 return (Log) logConstructor.newInstance(aClass);
68 } catch (Throwable t) {
69 throw new RuntimeException("Error creating logger for class " + aClass + ". Cause: " + t, t);
70 }
71 }
72
73 /**
74 * This method will switch the logging implementation to Log4J if Log4J is available on the classpath. This is useful
75 * in situations where you want to use Log4J to log iBATIS activity but commons logging is on the classpath. Note that
76 * this method is only effective for log classes obtained after calling this method. If you intend to use this method
77 * you should call it before calling any other iBATIS method.
78 */
79 public static synchronized void selectLog4JLogging() {
80 try {
81 Resources.classForName("org.apache.log4j.Logger");
82 Class implClass = Resources.classForName("com.ibatis.common.logging.log4j.Log4jImpl");
83 logConstructor = implClass.getConstructor(Class.class);
84 } catch (Throwable t) {
85 }
86 }
87
88 /**
89 * This method will switch the logging implementation to Java native logging if you are running in JRE 1.4 or above.
90 * This is useful in situations where you want to use Java native logging to log iBATIS activity but commons logging
91 * or Log4J is on the classpath. Note that this method is only effective for log classes obtained after calling this
92 * method. If you intend to use this method you should call it before calling any other iBATIS method.
93 */
94 public static synchronized void selectJavaLogging() {
95 try {
96 Resources.classForName("java.util.logging.Logger");
97 Class implClass = Resources.classForName("com.ibatis.common.logging.jdk14.Jdk14LoggingImpl");
98 logConstructor = implClass.getConstructor(Class.class);
99 } catch (Throwable t) {
100 }
101 }
102 }