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package javax.json;
/**
* <code>JsonValue</code> represents an immutable JSON value.
*
*
* <p>A JSON value is one of the following:
* an object ({@link JsonObject}), an array ({@link JsonArray}),
* a number ({@link JsonNumber}), a string ({@link JsonString}),
* {@code true} ({@link JsonValue#TRUE JsonValue.TRUE}), {@code false}
* ({@link JsonValue#FALSE JsonValue.FALSE}),
* or {@code null} ({@link JsonValue#NULL JsonValue.NULL}).
*
* @author Jitendra Kotamraju
*/
public interface JsonValue {
/**
* Indicates the type of a {@link JsonValue} object.
*/
enum ValueType {
/**
* JSON array.
*/
ARRAY,
/**
* JSON object.
*/
OBJECT,
/**
* JSON string.
*/
STRING,
/**
* JSON number.
*/
NUMBER,
/**
* JSON true.
*/
TRUE,
/**
* JSON false.
*/
FALSE,
/**
* JSON null.
*/
NULL
}
/**
* JSON null value.
*/
static final JsonValue NULL = new JsonValue() {
@Override
public ValueType getValueType() {
return ValueType.NULL;
}
/**
* Compares the specified object with this {@link JsonValue#NULL}
* object for equality. Returns {@code true} if and only if the
* specified object is also a {@code JsonValue}, and their
* {@link #getValueType()} objects are <i>equal</i>.
*
* @param obj the object to be compared for equality with this
* {@code JsonValue}
* @return {@code true} if the specified object is equal to this
* {@code JsonValue}
*/
@Override
public boolean equals(Object obj) {
if (obj instanceof JsonValue) {
return getValueType().equals(((JsonValue)obj).getValueType());
}
return false;
}
/**
* Returns the hash code value for this {@link JsonValue#NULL} object.
* The hash code of the {@link JsonValue#NULL} object is defined to be
* its {@link #getValueType()} object's hash code.
*
* @return the hash code value for this JsonString object
*/
@Override
public int hashCode() {
return ValueType.NULL.hashCode();
}
/**
* Returns a "null" string.
*
* @return "null"
*/
@Override
public String toString() {
return "null";
}
};
/**
* JSON true value.
*/
static final JsonValue TRUE = new JsonValue() {
@Override
public ValueType getValueType() {
return ValueType.TRUE;
}
/**
* Compares the specified object with this {@link JsonValue#TRUE}
* object for equality. Returns {@code true} if and only if the
* specified object is also a JsonValue, and their
* {@link #getValueType()} objects are <i>equal</i>.
*
* @param obj the object to be compared for equality with this JsonValue.
* @return {@code true} if the specified object is equal to this JsonValue.
*/
@Override
public boolean equals(Object obj) {
if (obj instanceof JsonValue) {
return getValueType().equals(((JsonValue)obj).getValueType());
}
return false;
}
/**
* Returns the hash code value for this {@link JsonValue#TRUE} object.
* The hash code of the {@link JsonValue#TRUE} object is defined to be
* its {@link #getValueType()} object's hash code.
*
* @return the hash code value for this JsonString object
*/
@Override
public int hashCode() {
return ValueType.TRUE.hashCode();
}
/**
* Returns "true" string
*
* @return "true"
*/
@Override
public String toString() {
return "true";
}
};
/**
* JSON false value
*/
static final JsonValue FALSE = new JsonValue() {
@Override
public ValueType getValueType() {
return ValueType.FALSE;
}
/**
* Compares the specified object with this {@link JsonValue#FALSE}
* object for equality. Returns {@code true} if and only if the
* specified object is also a JsonValue, and their
* {@link #getValueType()} objects are <i>equal</i>.
*
* @param obj the object to be compared for equality with this JsonValue
* @return {@code true} if the specified object is equal to this JsonValue
*/
@Override
public boolean equals(Object obj) {
if (obj instanceof JsonValue) {
return getValueType().equals(((JsonValue)obj).getValueType());
}
return false;
}
/**
* Returns the hash code value for this {@link JsonValue#FALSE} object.
* The hash code of the {@link JsonValue#FALSE} object is defined to be
* its {@link #getValueType()} object's hash code.
*
* @return the hash code value for this JsonString object
*/
@Override
public int hashCode() {
return ValueType.FALSE.hashCode();
}
/**
* Returns "false" string
*
* @return "false"
*/
@Override
public String toString() {
return "false";
}
};
/**
* Returns the value type of this JSON value.
*
* @return JSON value type
*/
ValueType getValueType();
/**
* Returns JSON text for this JSON value.
*
* @return JSON text
*/
@Override
String toString();
}