| /* |
| * Copyright (C) 2006 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.util; |
| |
| import com.android.internal.os.RuntimeInit; |
| |
| import java.io.PrintWriter; |
| import java.io.StringWriter; |
| |
| /** |
| * API for sending log output. |
| * |
| * <p>Generally, use the Log.v() Log.d() Log.i() Log.w() and Log.e() |
| * methods. |
| * |
| * <p>The order in terms of verbosity, from least to most is |
| * ERROR, WARN, INFO, DEBUG, VERBOSE. Verbose should never be compiled |
| * into an application except during development. Debug logs are compiled |
| * in but stripped at runtime. Error, warning and info logs are always kept. |
| * |
| * <p><b>Tip:</b> A good convention is to declare a <code>TAG</code> constant |
| * in your class: |
| * |
| * <pre>private static final String TAG = "MyActivity";</pre> |
| * |
| * and use that in subsequent calls to the log methods. |
| * </p> |
| * |
| * <p><b>Tip:</b> Don't forget that when you make a call like |
| * <pre>Log.v(TAG, "index=" + i);</pre> |
| * that when you're building the string to pass into Log.d, the compiler uses a |
| * StringBuilder and at least three allocations occur: the StringBuilder |
| * itself, the buffer, and the String object. Realistically, there is also |
| * another buffer allocation and copy, and even more pressure on the gc. |
| * That means that if your log message is filtered out, you might be doing |
| * significant work and incurring significant overhead. |
| */ |
| public final class Log { |
| |
| /** |
| * Priority constant for the println method; use Log.v. |
| */ |
| public static final int VERBOSE = 2; |
| |
| /** |
| * Priority constant for the println method; use Log.d. |
| */ |
| public static final int DEBUG = 3; |
| |
| /** |
| * Priority constant for the println method; use Log.i. |
| */ |
| public static final int INFO = 4; |
| |
| /** |
| * Priority constant for the println method; use Log.w. |
| */ |
| public static final int WARN = 5; |
| |
| /** |
| * Priority constant for the println method; use Log.e. |
| */ |
| public static final int ERROR = 6; |
| |
| /** |
| * Priority constant for the println method. |
| */ |
| public static final int ASSERT = 7; |
| |
| private Log() { |
| } |
| |
| /** |
| * Send a {@link #VERBOSE} log message. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| */ |
| public static int v(String tag, String msg) { |
| return println(VERBOSE, tag, msg); |
| } |
| |
| /** |
| * Send a {@link #VERBOSE} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log |
| */ |
| public static int v(String tag, String msg, Throwable tr) { |
| return println(VERBOSE, tag, msg + '\n' + getStackTraceString(tr)); |
| } |
| |
| /** |
| * Send a {@link #DEBUG} log message. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| */ |
| public static int d(String tag, String msg) { |
| return println(DEBUG, tag, msg); |
| } |
| |
| /** |
| * Send a {@link #DEBUG} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log |
| */ |
| public static int d(String tag, String msg, Throwable tr) { |
| return println(DEBUG, tag, msg + '\n' + getStackTraceString(tr)); |
| } |
| |
| /** |
| * Send an {@link #INFO} log message. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| */ |
| public static int i(String tag, String msg) { |
| return println(INFO, tag, msg); |
| } |
| |
| /** |
| * Send a {@link #INFO} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log |
| */ |
| public static int i(String tag, String msg, Throwable tr) { |
| return println(INFO, tag, msg + '\n' + getStackTraceString(tr)); |
| } |
| |
| /** |
| * Send a {@link #WARN} log message. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| */ |
| public static int w(String tag, String msg) { |
| return println(WARN, tag, msg); |
| } |
| |
| /** |
| * Send a {@link #WARN} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log |
| */ |
| public static int w(String tag, String msg, Throwable tr) { |
| return println(WARN, tag, msg + '\n' + getStackTraceString(tr)); |
| } |
| |
| /** |
| * Checks to see whether or not a log for the specified tag is loggable at the specified level. |
| * |
| * The default level of any tag is set to INFO. This means that any level above and including |
| * INFO will be logged. Before you make any calls to a logging method you should check to see |
| * if your tag should be logged. You can change the default level by setting a system property: |
| * 'setprop log.tag.<YOUR_LOG_TAG> <LEVEL>' |
| * Where level is either VERBOSE, DEBUG, INFO, WARN, ERROR, ASSERT, or SUPPRESS. SUPRESS will |
| * turn off all logging for your tag. You can also create a local.prop file that with the |
| * following in it: |
| * 'log.tag.<YOUR_LOG_TAG>=<LEVEL>' |
| * and place that in /data/local.prop. |
| * |
| * @param tag The tag to check. |
| * @param level The level to check. |
| * @return Whether or not that this is allowed to be logged. |
| * @throws IllegalArgumentException is thrown if the tag.length() > 23. |
| */ |
| public static native boolean isLoggable(String tag, int level); |
| |
| /* |
| * Send a {@link #WARN} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param tr An exception to log |
| */ |
| public static int w(String tag, Throwable tr) { |
| return println(WARN, tag, getStackTraceString(tr)); |
| } |
| |
| /** |
| * Send an {@link #ERROR} log message. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| */ |
| public static int e(String tag, String msg) { |
| return println(ERROR, tag, msg); |
| } |
| |
| /** |
| * Send a {@link #ERROR} log message and log the exception. |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @param tr An exception to log |
| */ |
| public static int e(String tag, String msg, Throwable tr) { |
| return println(ERROR, tag, msg + '\n' + getStackTraceString(tr)); |
| } |
| |
| /** |
| * Handy function to get a loggable stack trace from a Throwable |
| * @param tr An exception to log |
| */ |
| public static String getStackTraceString(Throwable tr) { |
| if (tr == null) { |
| return ""; |
| } |
| StringWriter sw = new StringWriter(); |
| PrintWriter pw = new PrintWriter(sw); |
| tr.printStackTrace(pw); |
| return sw.toString(); |
| } |
| |
| /** |
| * Low-level logging call. |
| * @param priority The priority/type of this log message |
| * @param tag Used to identify the source of a log message. It usually identifies |
| * the class or activity where the log call occurs. |
| * @param msg The message you would like logged. |
| * @return The number of bytes written. |
| */ |
| public static native int println(int priority, String tag, String msg); |
| } |