package android.util;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.UnknownHostException;
import java.util.logging.ConsoleHandler;
import java.util.logging.ErrorManager;
import java.util.logging.FileHandler;
import java.util.logging.Formatter;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogRecord;
import java.util.logging.Logger;
import static com.applang.Util.*;
/**
* 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
{
public static final Logger logger = Logger.getLogger("com.applang");
public static class LogFormatter extends Formatter
{
@Override
public String format(LogRecord record) {
StringBuilder sb = new StringBuilder();
sb.append(formatDate(now()));
sb.append(String.format(" %s : ", record.getLevel()));
sb.append(formatMessage(record));
sb.append("\n");
return sb.toString();
}
}
public static void logConsoleHandling(int priority) {
try {
Logger rootLogger = Logger.getLogger("");
for (Handler handler : rootLogger.getHandlers())
if (handler instanceof ConsoleHandler) {
((ConsoleHandler) handler).setFormatter(new LogFormatter());
break;
}
Log.changeLogLevel(priority);
} catch (Exception ex) {
new ErrorManager().error("logConsoleHandling", ex, ErrorManager.GENERIC_FAILURE);
}
}
public static void logFileHandling(String pattern, int limit, int count, boolean append) {
// logFileHandling("%t/" + TAG + "-log.%u-%g.txt", 8192, 5, false)
try {
Logger rootLogger = Logger.getLogger("");
for (Handler handler : rootLogger.getHandlers())
if (handler instanceof ConsoleHandler) {
rootLogger.removeHandler(handler);
break;
}
FileHandler fileHandler = new FileHandler(pattern, limit, count, append);
fileHandler.setFormatter(new LogFormatter());
rootLogger.addHandler(fileHandler);
} catch (Exception ex) {
new ErrorManager().error("logFileHandling", ex, ErrorManager.GENERIC_FAILURE);
}
}
/*
* set different levels for the logger plus a handler in order to take effect !!!
*/
public static void changeLogLevel(int priority) {
Level level = toLevel(priority);
Log.logger.setLevel(level);
Logger rootLogger = Logger.getLogger("");
rootLogger.getHandlers()[0].setLevel(level);
}
/**
* 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;
/**
* Exception class used to capture a stack trace in {@link #wtf()}.
*/
private static class TerribleFailure extends Exception {
TerribleFailure(String msg, Throwable cause) { super(msg, cause); }
}
/**
* Interface to handle terrible failures from {@link #wtf()}.
*
* @hide
*/
public interface TerribleFailureHandler {
void onTerribleFailure(String tag, TerribleFailure what);
}
private static TerribleFailureHandler sWtfHandler = new TerribleFailureHandler() {
public void onTerribleFailure(String tag, TerribleFailure what) {
wtf(tag, what);
}
};
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(LOG_ID_MAIN, 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(LOG_ID_MAIN, 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(LOG_ID_MAIN, 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(LOG_ID_MAIN, 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(LOG_ID_MAIN, 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(LOG_ID_MAIN, 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(LOG_ID_MAIN, 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(LOG_ID_MAIN, WARN, tag, msg + '\n' + getStackTraceString(tr));
}
/*
* 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(LOG_ID_MAIN, 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(LOG_ID_MAIN, 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(LOG_ID_MAIN, ERROR, tag, msg + '\n' + getStackTraceString(tr));
}
/**
* What a Terrible Failure: Report a condition that should never happen.
* The error will always be logged at level ASSERT with the call stack.
* Depending on system configuration, a report may be added to the
* {@link android.os.DropBoxManager} and/or the process may be terminated
* immediately with an error dialog.
* @param tag Used to identify the source of a log message.
* @param msg The message you would like logged.
*/
public static int wtf(String tag, String msg) {
return wtf(tag, msg, null);
}
/**
* What a Terrible Failure: Report an exception that should never happen.
* Similar to {@link #wtf(String, String)}, with an exception to log.
* @param tag Used to identify the source of a log message.
* @param tr An exception to log.
*/
public static int wtf(String tag, Throwable tr) {
return wtf(tag, tr.getMessage(), tr);
}
/**
* What a Terrible Failure: Report an exception that should never happen.
* Similar to {@link #wtf(String, Throwable)}, with a message as well.
* @param tag Used to identify the source of a log message.
* @param msg The message you would like logged.
* @param tr An exception to log. May be null.
*/
public static int wtf(String tag, String msg, Throwable tr) {
TerribleFailure what = new TerribleFailure(msg, tr);
int bytes = println(LOG_ID_MAIN, ASSERT, tag, msg + '\n' + getStackTraceString(tr));
sWtfHandler.onTerribleFailure(tag, what);
return bytes;
}
/**
* Sets the terrible failure handler, for testing.
*
* @return the old handler
*
* @hide
*/
public static TerribleFailureHandler setWtfHandler(TerribleFailureHandler handler) {
if (handler == null) {
throw new NullPointerException("handler == null");
}
TerribleFailureHandler oldHandler = sWtfHandler;
sWtfHandler = handler;
return oldHandler;
}
/**
* 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 "";
}
// This is to reduce the amount of log spew that apps do in the non-error
// condition of the network being unavailable.
Throwable t = tr;
while (t != null) {
if (t instanceof UnknownHostException) {
return "";
}
t = t.getCause();
}
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 int println(int bufId, int priority, String tag, String msg) {
if (!isLoggable(tag, priority))
return -1;
StringBuilder s = new StringBuilder("[" + tag + "] ");
if (msg != null)
s.append(msg);
logger.log(toLevel(priority), s.toString());
return 0;
}
/** @hide */ public static final int LOG_ID_MAIN = 0;
/** @hide */ public static final int LOG_ID_RADIO = 1;
/** @hide */ public static final int LOG_ID_EVENTS = 2;
/** @hide */ public static final int LOG_ID_SYSTEM = 3;
/**
* 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. SUPPRESS 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 priority) {
Level lvl = toLevel(priority);
return logger.isLoggable(lvl);
}
static Level toLevel(int priority) {
switch (priority) {
case VERBOSE:
return Level.FINER;
case DEBUG:
return Level.FINE;
case INFO:
return Level.INFO;
case WARN:
return Level.WARNING;
case ERROR:
return Level.SEVERE;
case ASSERT:
return Level.FINEST;
default:
return Level.OFF;
}
}
}