/*
* Copyright (C) 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.gson;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
/**
* A class representing an array type in Json. An array is a list of {@link JsonElement}s each of
* which can be of a different type. This is an ordered list, meaning that the order in which
* elements are added is preserved.
*
* @author Inderjeet Singh
* @author Joel Leitch
*/
public final class JsonArray extends JsonElement implements Iterable<JsonElement> {
private final List<JsonElement> elements;
/**
* Creates an empty JsonArray.
*/
public JsonArray() {
elements = new ArrayList<JsonElement>();
}
/**
* Adds the specified element to self.
*
* @param element the element that needs to be added to the array.
*/
public void add(JsonElement element) {
if (element == null) {
element = JsonNull.INSTANCE;
}
elements.add(element);
}
/**
* Adds all the elements of the specified array to self.
*
* @param array the array whose elements need to be added to the array.
*/
public void addAll(JsonArray array) {
elements.addAll(array.elements);
}
/**
* Returns the number of elements in the array.
*
* @return the number of elements in the array.
*/
public int size() {
return elements.size();
}
/**
* Returns an iterator to navigate the elemetns of the array. Since the array is an ordered list,
* the iterator navigates the elements in the order they were inserted.
*
* @return an iterator to navigate the elements of the array.
*/
public Iterator<JsonElement> iterator() {
return elements.iterator();
}
/**
* Returns the ith element of the array.
*
* @param i the index of the element that is being sought.
* @return the element present at the ith index.
* @throws IndexOutOfBoundsException if i is negative or greater than or equal to the
* {@link #size()} of the array.
*/
public JsonElement get(int i) {
return elements.get(i);
}
/**
* convenience method to get this array as a {@link Number} if it contains a single element.
*
* @return get this element as a number if it is single element array.
* @throws ClassCastException if the element in the array is of not a {@link JsonPrimitive} and
* is not a valid Number.
* @throws IllegalStateException if the array has more than one element.
*/
@Override
public Number getAsNumber() {
if (elements.size() == 1) {
return elements.get(0).getAsNumber();
}
throw new IllegalStateException();
}
/**
* convenience method to get this array as a {@link String} if it contains a single element.
*
* @return get this element as a String if it is single element array.
* @throws ClassCastException if the element in the array is of not a {@link JsonPrimitive} and
* is not a valid String.
* @throws IllegalStateException if the array has more than one element.
*/
@Override
public String getAsString() {
if (elements.size() == 1) {
return elements.get(0).getAsString();
}
throw new IllegalStateException();
}
/**
* convenience method to get this array as a double if it contains a single element.
*
* @return get this element as a double if it is single element array.
* @throws ClassCastException if the element in the array is of not a {@link JsonPrimitive} and
* is not a valid double.
* @throws IllegalStateException if the array has more than one element.
*/
@Override
public double getAsDouble() {
if (elements.size() == 1) {
return elements.get(0).getAsDouble();
}
throw new IllegalStateException();
}
/**
* convenience method to get this array as a {@link BigDecimal} if it contains a single element.
*
* @return get this element as a {@link BigDecimal} if it is single element array.
* @throws ClassCastException if the element in the array is of not a {@link JsonPrimitive}.
* @throws NumberFormatException if the element at index 0 is not a valid {@link BigDecimal}.
* @throws IllegalStateException if the array has more than one element.
* @since 1.2
*/
@Override
public BigDecimal getAsBigDecimal() {
if (elements.size() == 1) {
return elements.get(0).getAsBigDecimal();
}
throw new IllegalStateException();
}
/**
* convenience method to get this array as a {@link BigInteger} if it contains a single element.
*
* @return get this element as a {@link BigInteger} if it is single element array.
* @throws ClassCastException if the element in the array is of not a {@link JsonPrimitive}.
* @throws NumberFormatException if the element at index 0 is not a valid {@link BigInteger}.
* @throws IllegalStateException if the array has more than one element.
* @since 1.2
*/
@Override
public BigInteger getAsBigInteger() {
if (elements.size() == 1) {
return elements.get(0).getAsBigInteger();
}
throw new IllegalStateException();
}
/**
* convenience method to get this array as a float if it contains a single element.
*
* @return get this element as a float if it is single element array.
* @throws ClassCastException if the element in the array is of not a {@link JsonPrimitive} and
* is not a valid float.
* @throws IllegalStateException if the array has more than one element.
*/
@Override
public float getAsFloat() {
if (elements.size() == 1) {
return elements.get(0).getAsFloat();
}
throw new IllegalStateException();
}
/**
* convenience method to get this array as a long if it contains a single element.
*
* @return get this element as a long if it is single element array.
* @throws ClassCastException if the element in the array is of not a {@link JsonPrimitive} and
* is not a valid long.
* @throws IllegalStateException if the array has more than one element.
*/
@Override
public long getAsLong() {
if (elements.size() == 1) {
return elements.get(0).getAsLong();
}
throw new IllegalStateException();
}
/**
* convenience method to get this array as an integer if it contains a single element.
*
* @return get this element as an integer if it is single element array.
* @throws ClassCastException if the element in the array is of not a {@link JsonPrimitive} and
* is not a valid integer.
* @throws IllegalStateException if the array has more than one element.
*/
@Override
public int getAsInt() {
if (elements.size() == 1) {
return elements.get(0).getAsInt();
}
throw new IllegalStateException();
}
@Override
public byte getAsByte() {
if (elements.size() == 1) {
return elements.get(0).getAsByte();
}
throw new IllegalStateException();
}
@Override
public char getAsCharacter() {
if (elements.size() == 1) {
return elements.get(0).getAsCharacter();
}
throw new IllegalStateException();
}
/**
* convenience method to get this array as a primitive short if it contains a single element.
*
* @return get this element as a primitive short if it is single element array.
* @throws ClassCastException if the element in the array is of not a {@link JsonPrimitive} and
* is not a valid short.
* @throws IllegalStateException if the array has more than one element.
*/
@Override
public short getAsShort() {
if (elements.size() == 1) {
return elements.get(0).getAsShort();
}
throw new IllegalStateException();
}
/**
* convenience method to get this array as a boolean if it contains a single element.
*
* @return get this element as a boolean if it is single element array.
* @throws ClassCastException if the element in the array is of not a {@link JsonPrimitive} and
* is not a valid boolean.
* @throws IllegalStateException if the array has more than one element.
*/
@Override
public boolean getAsBoolean() {
if (elements.size() == 1) {
return elements.get(0).getAsBoolean();
}
throw new IllegalStateException();
}
@Override
public boolean equals(Object o) {
return (o == this) || (o instanceof JsonArray && ((JsonArray) o).elements.equals(elements));
}
@Override
public int hashCode() {
return elements.hashCode();
}
}