android.util.Log#println ( )源码实例Demo

/**
 * Prints data out to the console using Android's native log mechanism.
 * @param priority Log level of the data being logged.  Verbose, Error, etc.
 * @param tag Tag for for the log data.  Can be used to organize log statements.
 * @param msg The actual message to be logged. The actual message to be logged.
 * @param tr If an exception was thrown, this can be sent along for the logging facilities
 *           to extract and print useful information.
 */
@Override
public void println(int priority, String tag, String msg, Throwable tr) {
    // There actually are log methods that don't take a msg parameter.  For now,
    // if that's the case, just convert null to the empty string and move on.
    String useMsg = msg;
    if (useMsg == null) {
        useMsg = "";
    }

    // If an exeption was provided, convert that exception to a usable string and attach
    // it to the end of the msg method.
    if (tr != null) {
        msg += "\n" + Log.getStackTraceString(tr);
    }

    // This is functionally identical to Log.x(tag, useMsg);
    // For instance, if priority were Log.VERBOSE, this would be the same as Log.v(tag, useMsg)
    Log.println(priority, tag, useMsg);

    // If this isn't the last node in the chain, move things along.
    if (mNext != null) {
        mNext.println(priority, tag, msg, tr);
    }
}
 

/**
 * Prints data out to the console using Android's native log mechanism.
 *
 * @param priority Log level of the data being logged.  Verbose, Error, etc.
 * @param tag      Tag for for the log data.  Can be used to organize log statements.
 * @param msg      The actual message to be logged. The actual message to be logged.
 * @param tr       If an exception was thrown, this can be sent along for the logging
 *                 facilities
 *                 to extract and print useful information.
 */
@Override
public void println(int priority, String tag, String msg, Throwable tr) {
    // There actually are log methods that don't take a msg parameter.  For now,
    // if that's the case, just convert null to the empty string and move on.
    String useMsg = msg;
    if (useMsg == null) {
        useMsg = "";
    }

    // If an exeption was provided, convert that exception to a usable string and attach
    // it to the end of the msg method.
    if (tr != null) {
        msg += "\n" + Log.getStackTraceString(tr);
    }

    // This is functionally identical to Log.x(tag, useMsg);
    // For instance, if priority were Log.VERBOSE, this would be the same as Log.v(tag, useMsg)
    Log.println(priority, tag, useMsg);

    // If this isn't the last node in the chain, move things along.
    if (mNext != null) {
        mNext.println(priority, tag, msg, tr);
    }
}
 

/**
 * Prints data out to the console using Android's native log mechanism.
 * @param priority Log level of the data being logged.  Verbose, Error, etc.
 * @param tag Tag for for the log data.  Can be used to organize log statements.
 * @param msg The actual message to be logged. The actual message to be logged.
 * @param tr If an exception was thrown, this can be sent along for the logging facilities
 *           to extract and print useful information.
 */
@Override
public void println(int priority, String tag, String msg, Throwable tr) {
    // There actually are log methods that don't take a msg parameter.  For now,
    // if that's the case, just convert null to the empty string and move on.
    String useMsg = msg;
    if (useMsg == null) {
        useMsg = "";
    }

    // If an exeption was provided, convert that exception to a usable string and attach
    // it to the end of the msg method.
    if (tr != null) {
        msg += "\n" + Log.getStackTraceString(tr);
    }

    // This is functionally identical to Log.x(tag, useMsg);
    // For instance, if priority were Log.VERBOSE, this would be the same as Log.v(tag, useMsg)
    Log.println(priority, tag, useMsg);

    // If this isn't the last node in the chain, move things along.
    if (mNext != null) {
        mNext.println(priority, tag, msg, tr);
    }
}
 

private static void log(String tag, int level, Throwable t, Object... messages) {
    String message;
    if (t == null && messages != null && messages.length == 1) {
        // handle this common case without the extra cost of creating a stringBuffer:
        message = messages[0].toString();
    } else {
        StringBuilder sb = new StringBuilder();
        if (messages != null) for (Object m : messages) {
            sb.append(m);
        }
        if (t != null) {
            sb.append("\n").append(Log.getStackTraceString(t));
        }
        message = sb.toString();
    }
    Log.println(level, tag, message);
}
 

/**
 * Prints data out to the console using Android's native log mechanism.
 *
 * @param priority Log level of the data being logged.  Verbose, Error, etc.
 * @param tag      Tag for for the log data.  Can be used to organize log statements.
 * @param msg      The actual message to be logged. The actual message to be logged.
 * @param tr       If an exception was thrown, this can be sent along for the logging
 *                 facilities
 *                 to extract and print useful information.
 */
@Override
public void println(int priority, String tag, String msg, Throwable tr) {
    // There actually are log methods that don't take a msg parameter.  For now,
    // if that's the case, just convert null to the empty string and move on.
    String useMsg = msg;
    if (useMsg == null) {
        useMsg = "";
    }

    // If an exeption was provided, convert that exception to a usable string and attach
    // it to the end of the msg method.
    if (tr != null) {
        msg += "\n" + Log.getStackTraceString(tr);
    }

    // This is functionally identical to Log.x(tag, useMsg);
    // For instance, if priority were Log.VERBOSE, this would be the same as Log.v(tag, useMsg)
    Log.println(priority, tag, useMsg);

    // If this isn't the last node in the chain, move things along.
    if (mNext != null) {
        mNext.println(priority, tag, msg, tr);
    }
}
 

/**
 * Prints data out to the console using Android's native log mechanism.
 * @param priority Log level of the data being logged.  Verbose, Error, etc.
 * @param tag Tag for for the log data.  Can be used to organize log statements.
 * @param msg The actual message to be logged. The actual message to be logged.
 * @param tr If an exception was thrown, this can be sent along for the logging facilities
 *           to extract and print useful information.
 */
@Override
public void println(int priority, String tag, String msg, Throwable tr) {
    // There actually are log methods that don't take a msg parameter.  For now,
    // if that's the case, just convert null to the empty string and move on.
    String useMsg = msg;
    if (useMsg == null) {
        useMsg = "";
    }

    // If an exeption was provided, convert that exception to a usable string and attach
    // it to the end of the msg method.
    if (tr != null) {
        msg += "\n" + Log.getStackTraceString(tr);
    }

    // This is functionally identical to Log.x(tag, useMsg);
    // For instance, if priority were Log.VERBOSE, this would be the same as Log.v(tag, useMsg)
    Log.println(priority, tag, useMsg);

    // If this isn't the last node in the chain, move things along.
    if (mNext != null) {
        mNext.println(priority, tag, msg, tr);
    }
}
 

private static int println(int level, String tag, String msg) {
  if (LOG_LEVEL <= level) {
    return Log.println(level, tag, TextUtils.isEmpty(msg) ? "null" : msg);
  } else {
    return -1;
  }
}
 

private void throwShade(int priority, String message, Throwable t) {
    if (message == null || message.length() == 0) {
        if (t != null) {
            message = Log.getStackTraceString(t);
        } else {
            // Swallow message if it's null and there's no throwable.
            return;
        }
    } else if (t != null) {
        message += "\n" + Log.getStackTraceString(t);
    }

    String tag = createTag();
    if (message.length() < 4000) {
        /*
         * Replacing the original tag with the application tag and
         * using the tag for the class formatted at the beginning.
         */
        String taggedMessage = String.format("%s -> %s", tag, message);
        Log.println(priority, applicationTag, taggedMessage);
    } else {
        // It's rare that the message will be this large, so we're ok with the perf hit of splitting
        // and calling Log.println N times.  It's possible but unlikely that a single line will be
        // longer than 4000 characters: we're explicitly ignoring this case here.
        String[] lines = message.split("\n");
        for (String line : lines) {
            Log.println(priority, tag, line);
        }
    }
}
 

private static void printSubMsg(final int type, final String tag, final String msg) {
    if (!CONFIG.isLogBorderSwitch()) {
        Log.println(type, tag, msg);
        return;
    }
    StringBuilder sb = new StringBuilder();
    String[] lines = msg.split(LINE_SEP);
    for (String line : lines) {
        Log.println(type, tag, LEFT_BORDER + line);
    }
}
 

public static void w(String message) {
    if (!DEVELOP_MODE || TextUtils.isEmpty(message)) {
        return;
    }
    final StackTraceElement[] stack = new Throwable().getStackTrace();
    final int i = 1;
    final StackTraceElement ste = stack[i];
    Log.println(Log.WARN, LOG_TAG, String.format("[%s][%s][%s]%s", ste.getFileName(), ste.getMethodName(), ste.getLineNumber(), message));
}
 

private void log_private(int level, String tag, String message, StackTraceElement trace)
{
	message = prefixMessage(trace.getMethodName(), message);
	if (m_logger != null)
	{
		m_logger.onLogEntry(level, tag, message);
	}
	else
	{
		Log.println(level, tag, message);
	}
}
 

public static void e(String message) {
    if (!DEVELOP_MODE || TextUtils.isEmpty(message)) {
        return;
    }
    final StackTraceElement[] stack = new Throwable().getStackTrace();
    final int i = 1;
    final StackTraceElement ste = stack[i];
    Log.println(Log.ERROR, LOG_TAG, String.format("[%s][%s][%s]%s", ste.getFileName(), ste.getMethodName(), ste.getLineNumber(), message));
}
 

@Override
public boolean onException(Exception e, A model, Target<B> target, boolean isFirstResource) {
    Log.println(level, "GLIDE", String.format(Locale.ROOT,
            "%s.onException(%s, %s, %s, %s)\n%s",
            name, e, model, strip(target), isFirst(isFirstResource), Log.getStackTraceString(e)));
    return delegate.onException(e, model, target, isFirstResource);
}
 

private static void d(int i, String str, String str2) {
    if (!d) {
        str = "FlurryAgent";
    }
    int length = TextUtils.isEmpty(str2) ? 0 : str2.length();
    int i2 = 0;
    while (i2 < length) {
        int i3 = a > length - i2 ? length : a + i2;
        if (Log.println(i, str, str2.substring(i2, i3)) > 0) {
            i2 = i3;
        } else {
            return;
        }
    }
}
 

/**
 * Break up {@code message} into maximum-length chunks (if needed) and send to either
 * {@link Log#println(int, String, String) Log.println()} or
 * {@link Log#wtf(String, String) Log.wtf()} for logging.
 * <p>
 * {@inheritDoc}
 */
@Override
protected void log(int priority, String tag, String message, Throwable t) {
    if (message.length() < MAX_LOG_LENGTH) {
        if (priority == Log.ASSERT) {
            Log.wtf(tag, message);
        } else {
            Log.println(priority, tag, message);
        }
        return;
    }

    // Split by line, then ensure each line can fit into Log's maximum length.
    for (int i = 0, length = message.length(); i < length; i++) {
        int newline = message.indexOf('\n', i);
        newline = newline != -1 ? newline : length;
        do {
            int end = Math.min(newline, i + MAX_LOG_LENGTH);
            String part = message.substring(i, end);
            if (priority == Log.ASSERT) {
                Log.wtf(tag, part);
            } else {
                Log.println(priority, tag, part);
            }
            i = end;
        } while (i < newline);
    }
}
 

private static void printHead(final int type, final String tag, final String[] head) {
    if (head != null) {
        for (String aHead : head) {
            Log.println(type, tag, sLogBorderSwitch ? LEFT_BORDER + aHead : aHead);
        }
        if (sLogBorderSwitch) Log.println(type, tag, MIDDLE_BORDER);
    }
}
 

@Override
public void print(int level, StackTraceElement element, String tag, Object msg) {
    String className = element.getClassName();
    className = className.substring(className.lastIndexOf(".") + 1);
    String codeLine = className+'.'+element.getMethodName()+'('+element.getFileName()+':'+element.getLineNumber()+')';
    Log.println(level, tag, codeLine);

    String message = toString(msg);
    Log.println(level, tag, "\t" + message);
}
 

private static void printBorder(final int type, final String tag, boolean isTop) {
    if (sLogBorderSwitch) {
        Log.println(type, tag, isTop ? TOP_BORDER : BOTTOM_BORDER);
    }
}
 

private static void traceAndLog(int level, String message) {
    TraceEvent.instant("TraceEvent.LooperMonitor:IdleStats", message);
    Log.println(level, TAG, message);
}
 

private static void printBorder(final int type, final String tag, boolean isTop) {
    if (sConfig.mLogBorderSwitch) {
        Log.println(type, tag, isTop ? TOP_BORDER : BOTTOM_BORDER);
    }
}