com.tomtom.speedtools.loghelper

Class LogHelper

java.lang.Object

com.tomtom.speedtools.loghelper.LogHelper

public final class LogHelper
extends Object

Utility class to store (key, value) pairs, so human readable names can be used in log messages. For example, if an application creates a User with database ID N, it may wish to call logId(String, String) for N and userName, so subsequent log messages can use logId(String) for N only and show both the ID and the name.

     // Create user. ID and user name both known at this point.
     LOG.info("User created: {}", logId(id, name));
     ...
     // Finds user ID only. User name not known here, but inserted by log helper.
     LOG.info("Found user: {}", logId(id));
 

Note that the LogHelper class has a limited cache of (key, value) pairs, to limit memory usage. The cache auto-expires unused items as well.

Method Summary

Modifier and Type	Method and Description
static void	enable(boolean enable) Enable or disable the cache.
static boolean	isEnabled() Return whether the LogHelper is enabled or not.
static String	logId(String key) Get a value from the map.
static String	logId(String key, String value) Store a value from the key/value store and return the key with the value appended.
static String	logId(Uid<?> key) Get a value from the map.
static String	logId(Uid<?> key, String value) Store a value from the key/value store and return the key with the value appended.
static String	logIdName(String key) Get a name from the map.
static String	logIdName(Uid<?> key) Get only the name from the map.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

enable

public static void enable(boolean enable)

Enable or disable the cache. Normally, you would initialize the cache once with LogHelper.enable(LOG.isDebugEnabled());

Parameters:

enable - True to enable.

isEnabled

public static boolean isEnabled()

Return whether the LogHelper is enabled or not.

Returns:

True if enabled.

logId

@Nullable
public static String logId(@Nullable
                                     Uid<?> key,
                                     @Nullable
                                     String value)

Store a value from the key/value store and return the key with the value appended.

Parameters:

key - Unique key.

value - Value. If null, the key/value pair is effectively removed from the map.

Returns:

Key with value appended (if not null).

logId

@Nullable
public static String logId(@Nullable
                                     Uid<?> key)

Get a value from the map.

Parameters:

key - Unique key.

Returns:

Key with value appended (if not null).

logId

@Nullable
public static String logId(@Nullable
                                     String key,
                                     @Nullable
                                     String value)

Store a value from the key/value store and return the key with the value appended.

Parameters:

key - Unique key.

value - Value. If null, the key/value pair is effectively removed from the map.

Returns:

Key with value appended (if not null).

logId

@Nullable
public static String logId(@Nullable
                                     String key)

Get a value from the map.

Parameters:

key - Unique key.

Returns:

Key with value appended (if not null).

logIdName

@Nonnull
public static String logIdName(@Nullable
                                        Uid<?> key)

Get only the name from the map.

Parameters:

key - Unique key.

Returns:

Name if found, or key, or empty.

logIdName

@Nonnull
public static String logIdName(@Nullable
                                        String key)

Get a name from the map.

Parameters:

key - Unique key.

Returns:

Name, or key, or empty.