Default behavior outputs the log to {@link System#out}. Use {@link #setLogOutput(ILogOutput)}
* to redirect the log somewhere else.
*/
public final class Log {
/** Log Level enum. */
public enum LogLevel {
VERBOSE(2, "verbose", 'V'), // $NON-NLS-1$
DEBUG(3, "debug", 'D'), // $NON-NLS-1$
INFO(4, "info", 'I'), // $NON-NLS-1$
WARN(5, "warn", 'W'), // $NON-NLS-1$
ERROR(6, "error", 'E'), // $NON-NLS-1$
ASSERT(7, "assert", 'A'); // $NON-NLS-1$
private int mPriorityLevel;
private String mStringValue;
private char mPriorityLetter;
LogLevel(int intPriority, String stringValue, char priorityChar) {
mPriorityLevel = intPriority;
mStringValue = stringValue;
mPriorityLetter = priorityChar;
}
public static LogLevel getByString(String value) {
for (LogLevel mode : values()) {
if (mode.mStringValue.equals(value)) {
return mode;
}
}
return null;
}
/**
* Returns the {@link LogLevel} enum matching the specified letter.
*
* @param letter the letter matching a LogLevel enum
* @return a LogLevel object or null if no match were found.
*/
public static LogLevel getByLetter(char letter) {
for (LogLevel mode : values()) {
if (mode.mPriorityLetter == letter) {
return mode;
}
}
return null;
}
/**
* Returns the {@link LogLevel} enum matching the specified letter.
*
*
The letter is passed as a {@link String} argument, but only the first character is
* used.
*
* @param letter the letter matching a LogLevel enum
* @return a LogLevel object or null if no match were found.
*/
public static LogLevel getByLetterString(String letter) {
if (!letter.isEmpty()) {
return getByLetter(letter.charAt(0));
}
return null;
}
/** Returns the letter identifying the priority of the {@link LogLevel}. */
public char getPriorityLetter() {
return mPriorityLetter;
}
/** Returns the numerical value of the priority. */
public int getPriority() {
return mPriorityLevel;
}
/** Returns a non translated string representing the LogLevel. */
public String getStringValue() {
return mStringValue;
}
public static LogLevel convertFromDdmlib(com.android.ddmlib.Log.LogLevel level) {
switch (level) {
case VERBOSE:
return VERBOSE;
case DEBUG:
return DEBUG;
case INFO:
return INFO;
case WARN:
return WARN;
case ERROR:
return ERROR;
case ASSERT:
return ASSERT;
default:
return VERBOSE;
}
}
}
/**
* Classes which implement this interface provides methods that deal with outputting log
* messages.
*/
public interface ILogOutput {
/**
* Sent when a log message needs to be printed.
*
* @param logLevel The {@link LogLevel} enum representing the priority of the message.
* @param tag The tag associated with the message.
* @param message The message to display.
*/
public void printLog(LogLevel logLevel, String tag, String message);
/**
* Sent when a log message needs to be printed, and, if possible, displayed to the user in a
* dialog box.
*
* @param logLevel The {@link LogLevel} enum representing the priority of the message.
* @param tag The tag associated with the message.
* @param message The message to display.
*/
public void printAndPromptLog(LogLevel logLevel, String tag, String message);
}
private static LogLevel sLevel = LogLevel.VERBOSE;
private static ILogOutput sLogOutput;
private Log() {}
/**
* Outputs a {@link LogLevel#VERBOSE} level message.
*
* @param tag The tag associated with the message.
* @param message The message to output.
*/
public static void v(String tag, String message) {
println(LogLevel.VERBOSE, tag, message);
}
/**
* Outputs a {@link LogLevel#DEBUG} level message.
*
* @param tag The tag associated with the message.
* @param message The message to output.
*/
public static void d(String tag, String message) {
println(LogLevel.DEBUG, tag, message);
}
/**
* Outputs a {@link LogLevel#INFO} level message.
*
* @param tag The tag associated with the message.
* @param message The message to output.
*/
public static void i(String tag, String message) {
println(LogLevel.INFO, tag, message);
}
/**
* Outputs a {@link LogLevel#WARN} level message.
*
* @param tag The tag associated with the message.
* @param message The message to output.
*/
public static void w(String tag, String message) {
println(LogLevel.WARN, tag, message);
}
/**
* Outputs a {@link LogLevel#ERROR} level message.
*
* @param tag The tag associated with the message.
* @param message The message to output.
*/
public static void e(String tag, String message) {
println(LogLevel.ERROR, tag, message);
}
/**
* Outputs a log message and attempts to display it in a dialog.
*
* @param tag The tag associated with the message.
* @param message The message to output.
*/
public static void logAndDisplay(LogLevel logLevel, String tag, String message) {
if (sLogOutput != null) {
sLogOutput.printAndPromptLog(logLevel, tag, message);
} else {
println(logLevel, tag, message);
}
}
/**
* Outputs a {@link LogLevel#ERROR} level {@link Throwable} information.
*
* @param tag The tag associated with the message.
* @param throwable The {@link Throwable} to output.
*/
public static void e(String tag, Throwable throwable) {
if (throwable != null) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
throwable.printStackTrace(pw);
println(LogLevel.ERROR, tag, throwable.getMessage() + '\n' + sw.toString());
}
}
static void setLevel(LogLevel logLevel) {
sLevel = logLevel;
}
/**
* Sets the {@link ILogOutput} to use to print the logs. If not set, {@link System#out} will be
* used.
*
* @param logOutput The {@link ILogOutput} to use to print the log.
*/
public static void setLogOutput(ILogOutput logOutput) {
sLogOutput = logOutput;
}
/* currently prints to stdout; could write to a log window */
private static void println(LogLevel logLevel, String tag, String message) {
if (logLevel.getPriority() >= sLevel.getPriority()) {
if (sLogOutput != null) {
sLogOutput.printLog(logLevel, tag, message);
} else {
printLog(logLevel, tag, message);
}
}
}
/**
* Prints a log message.
*
* @param logLevel
* @param tag
* @param message
*/
public static void printLog(LogLevel logLevel, String tag, String message) {
System.out.print(getLogFormatString(logLevel, tag, message));
}
/**
* Formats a log message.
*
* @param logLevel
* @param tag
* @param message
*/
public static String getLogFormatString(LogLevel logLevel, String tag, String message) {
SimpleDateFormat formatter = new SimpleDateFormat("MM-dd HH:mm:ss", Locale.getDefault());
return String.format(
"%s %c/%s: %s\n",
formatter.format(new Date()), logLevel.getPriorityLetter(), tag, message);
}
}