Class TagKey

java.lang.Object

io.opencensus.tags.TagKey

@Immutable
public abstract class TagKey
extends Object

A key to a value stored in a TagContext.

Each TagKey has a String name. Names have a maximum length of MAX_LENGTH and contain only printable ASCII characters.

TagKeys are designed to be used as constants. Declaring each key as a constant prevents key names from being validated multiple times.

Since:

0.8

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MAX_LENGTH	The maximum length for a tag key name.

Method Summary

Modifier and Type	Method	Description
static TagKey	create(String name)	Constructs a TagKey with the given name.
abstract String	getName()	Returns the name of the key.

Methods inherited from class Object

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

Field Details

MAX_LENGTH

public static final int MAX_LENGTH

The maximum length for a tag key name. The value is 255.

Since:

0.8

See Also:

• Constant Field Values

Method Details

create

public static TagKey create(String name)

Constructs a TagKey with the given name.

The name must meet the following requirements:

1. It cannot be longer than MAX_LENGTH.
2. It can only contain printable ASCII characters.

Parameters:

name - the name of the key.

Returns:

a TagKey with the given name.

Throws:

IllegalArgumentException - if the name is not valid.

Since:

0.8

getName

public abstract String getName()

Returns the name of the key.

Returns:

the name of the key.

Since:

0.8