a_vcard.android.util
Class Log

java.lang.Object
  extended by a_vcard.android.util.Log

public final class Log
extends java.lang.Object

API for sending log output.

Generally, use the Log.v() Log.d() Log.i() Log.w() and Log.e() methods.

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.

Tip: A good convention is to declare a TAG constant in your class:

private static final String TAG = "MyActivity";
and use that in subsequent calls to the log methods.

Tip: Don't forget that when you make a call like

Log.v(TAG, "index=" + i);
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.


Field Summary
static int ASSERT
          Priority constant for the println method.
static int DEBUG
          Priority constant for the println method; use Log.d.
static int ERROR
          Priority constant for the println method; use Log.e.
static int INFO
          Priority constant for the println method; use Log.i.
static int VERBOSE
          Priority constant for the println method; use Log.v.
static int WARN
          Priority constant for the println method; use Log.w.
 
Method Summary
static int d(java.lang.String tag, java.lang.String msg)
          Send a DEBUG log message.
static int d(java.lang.String tag, java.lang.String msg, java.lang.Throwable tr)
          Send a DEBUG log message and log the exception.
static int e(java.lang.String tag, java.lang.String msg)
          Send an ERROR log message.
static int e(java.lang.String tag, java.lang.String msg, java.lang.Throwable tr)
          Send a ERROR log message and log the exception.
static java.lang.String getStackTraceString(java.lang.Throwable tr)
          Handy function to get a loggable stack trace from a Throwable
static int i(java.lang.String tag, java.lang.String msg)
          Send an INFO log message.
static int i(java.lang.String tag, java.lang.String msg, java.lang.Throwable tr)
          Send a INFO log message and log the exception.
static boolean isLoggable(java.lang.String tag, int level)
          Checks to see whether or not a log for the specified tag is loggable at the specified level.
static int println(int priority, java.lang.String tag, java.lang.String msg)
          Low-level logging call.
static int v(java.lang.String tag, java.lang.String msg)
          Send a VERBOSE log message.
static int v(java.lang.String tag, java.lang.String msg, java.lang.Throwable tr)
          Send a VERBOSE log message and log the exception.
static int w(java.lang.String tag, java.lang.String msg)
          Send a WARN log message.
static int w(java.lang.String tag, java.lang.String msg, java.lang.Throwable tr)
          Send a WARN log message and log the exception.
static int w(java.lang.String tag, java.lang.Throwable tr)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

VERBOSE

public static final int VERBOSE
Priority constant for the println method; use Log.v.

See Also:
Constant Field Values

DEBUG

public static final int DEBUG
Priority constant for the println method; use Log.d.

See Also:
Constant Field Values

INFO

public static final int INFO
Priority constant for the println method; use Log.i.

See Also:
Constant Field Values

WARN

public static final int WARN
Priority constant for the println method; use Log.w.

See Also:
Constant Field Values

ERROR

public static final int ERROR
Priority constant for the println method; use Log.e.

See Also:
Constant Field Values

ASSERT

public static final int ASSERT
Priority constant for the println method.

See Also:
Constant Field Values
Method Detail

v

public static int v(java.lang.String tag,
                    java.lang.String msg)
Send a VERBOSE log message.

Parameters:
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.

v

public static int v(java.lang.String tag,
                    java.lang.String msg,
                    java.lang.Throwable tr)
Send a VERBOSE log message and log the exception.

Parameters:
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.
tr - An exception to log

d

public static int d(java.lang.String tag,
                    java.lang.String msg)
Send a DEBUG log message.

Parameters:
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.

d

public static int d(java.lang.String tag,
                    java.lang.String msg,
                    java.lang.Throwable tr)
Send a DEBUG log message and log the exception.

Parameters:
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.
tr - An exception to log

i

public static int i(java.lang.String tag,
                    java.lang.String msg)
Send an INFO log message.

Parameters:
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.

i

public static int i(java.lang.String tag,
                    java.lang.String msg,
                    java.lang.Throwable tr)
Send a INFO log message and log the exception.

Parameters:
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.
tr - An exception to log

w

public static int w(java.lang.String tag,
                    java.lang.String msg)
Send a WARN log message.

Parameters:
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.

w

public static int w(java.lang.String tag,
                    java.lang.String msg,
                    java.lang.Throwable tr)
Send a WARN log message and log the exception.

Parameters:
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.
tr - An exception to log

isLoggable

public static boolean isLoggable(java.lang.String tag,
                                 int level)
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.

Parameters:
tag - The tag to check.
level - The level to check.
Returns:
Whether or not that this is allowed to be logged.
Throws:
java.lang.IllegalArgumentException - is thrown if the tag.length() > 23.

w

public static int w(java.lang.String tag,
                    java.lang.Throwable tr)

e

public static int e(java.lang.String tag,
                    java.lang.String msg)
Send an ERROR log message.

Parameters:
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.

e

public static int e(java.lang.String tag,
                    java.lang.String msg,
                    java.lang.Throwable tr)
Send a ERROR log message and log the exception.

Parameters:
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.
tr - An exception to log

getStackTraceString

public static java.lang.String getStackTraceString(java.lang.Throwable tr)
Handy function to get a loggable stack trace from a Throwable

Parameters:
tr - An exception to log

println

public static int println(int priority,
                          java.lang.String tag,
                          java.lang.String msg)
Low-level logging call.

Parameters:
priority - The priority/type of this log message
tag - Used to identify the source of a log message. It usually identifies the class or activity where the log call occurs.
msg - The message you would like logged.
Returns:
The number of bytes written.