com.pdd.pop.ext.fasterxml.jackson.annotation.OptBoolean Maven / Gradle / Ivy
package com.pdd.pop.ext.fasterxml.jackson.annotation;
/**
* Optional Boolean value ("nullean"). Needed just because Java annotations
* can not take 'null' as a value (even as default), so there is no
* way to distinguish between explicit `true` and `false`, and lack of
* choice (related: annotations are limited to primitives, so
* {@link java.lang.Boolean} not allowed as solution).
*
* Note: although use of `true` and `false` would be more convenient, they
* can not be chosen since they are Java keyword and compiler won't allow
* the choice. And since enum naming convention suggests all-upper-case,
* that is what is done here.
*
* @since 2.6
*/
public enum OptBoolean
{
/**
* Value that indicates that the annotation property is explicitly defined to
* be enabled, or true.
*/
TRUE,
/**
* Value that indicates that the annotation property is explicitly defined to
* be disabled, or false.
*/
FALSE,
/**
* Value that indicates that the annotation property does NOT have an explicit
* definition of enabled/disabled (or true/false); instead, a higher-level
* configuration value is used; or lacking higher-level global setting,
* default.
*/
DEFAULT;
public Boolean asBoolean() {
if (this == DEFAULT) return null;
return (this == TRUE) ? Boolean.TRUE : Boolean.FALSE;
}
public boolean asPrimitive() {
return (this == TRUE);
}
public static OptBoolean fromBoolean(Boolean b) {
if (b == null) {
return DEFAULT;
}
return b.booleanValue() ? TRUE : FALSE;
}
public static boolean equals(Boolean b1, Boolean b2) {
if (b1 == null) {
return (b2 == null);
}
return b1.equals(b2);
}
}