TagKey

java.lang.Object
- io.opencensus.tags.TagKey

Direct Known Subclasses:

AutoValue_TagKey
```
@Immutable
public abstract class TagKey
extends java.lang.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 int MAX_LENGTH
The maximum length for a tag key name.

Constructor Summary

Constructors
Constructor Description

TagKey()

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`static TagKey`	`create(java.lang.String name)`	Constructs a `TagKey` with the given name.
`abstract java.lang.String`	`getName()`	Returns the name of the key.
`private static boolean`	`isValid(java.lang.String name)`	Determines whether the given `String` is a valid tag key.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - 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
- Constructor Detail
  - TagKey
```
TagKey()
```
- Method Detail
  - create
```
public static TagKey create(java.lang.String name)
```
    Constructs a TagKey with the given name.
    The name must meet the following requirements:
    
    It cannot be longer than MAX_LENGTH.
    It can only contain printable ASCII characters.
    Parameters:
    
    name - the name of the key.
    
    Returns:
    
    a TagKey with the given name.
    
    Throws:
    
    java.lang.IllegalArgumentException - if the name is not valid.
    
    Since:
    
    0.8
  - getName
```
public abstract java.lang.String getName()
```
    Returns the name of the key.
    
    Returns:
    
    the name of the key.
    
    Since:
    
    0.8
  - isValid
```
private static boolean isValid(java.lang.String name)
```
    Determines whether the given String is a valid tag key.
    
    Parameters:
    
    name - the tag key name to be validated.
    
    Returns:
    
    whether the name is valid.