48 lines
1.2 KiB
Java
48 lines
1.2 KiB
Java
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package javax.annotation;
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import java.lang.annotation.Documented;
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import java.lang.annotation.Retention;
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import java.lang.annotation.RetentionPolicy;
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import javax.annotation.meta.TypeQualifier;
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import javax.annotation.meta.TypeQualifierValidator;
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import javax.annotation.meta.When;
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/**
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* This annotation is used to annotate a value that should only contain
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* nonnegative values.
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* <p>
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* When this annotation is applied to a method it applies to the method return
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* value.
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*/
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@Documented
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@TypeQualifier(applicableTo = Number.class)
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@Retention(RetentionPolicy.RUNTIME)
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public @interface Nonnegative {
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When when() default When.ALWAYS;
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class Checker implements TypeQualifierValidator<Nonnegative> {
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public When forConstantValue(Nonnegative annotation, Object v) {
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if (!(v instanceof Number))
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return When.NEVER;
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boolean isNegative;
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Number value = (Number) v;
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if (value instanceof Long)
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isNegative = value.longValue() < 0;
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else if (value instanceof Double)
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isNegative = value.doubleValue() < 0;
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else if (value instanceof Float)
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isNegative = value.floatValue() < 0;
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else
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isNegative = value.intValue() < 0;
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if (isNegative)
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return When.NEVER;
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else
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return When.ALWAYS;
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}
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}
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}
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