com.eclipsesource.json.JsonArray Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2008, 2013 EclipseSource.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Ralf Sternberg - initial implementation and API
******************************************************************************/
package com.eclipsesource.json;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
/**
* Represents a JSON array, i.e. an ordered collection of JSON values.
*
* Elements can be added using the add(...) methods which accept instances of
* {@link JsonValue}, strings, primitive numbers, and boolean values. To replace an element of an
* array, use the set(int, ...) methods.
*
*
* Elements can be accessed by their index using {@link #get(int)}. This class also supports
* iterating over the elements in document order using an {@link #iterator()} or an enhanced for
* loop:
*
*
*
* for( JsonValue value : jsonArray ) {
* ...
* }
*
*
* An equivalent {@link List} can be obtained from the method {@link #values()}.
*
*
* Note that this class is not thread-safe. If multiple threads access a
* JsonArray instance concurrently, while at least one of these threads modifies the
* contents of this array, access to the instance must be synchronized externally. Failure to do so
* may lead to an inconsistent state.
*
*
* This class is not supposed to be extended by clients.
*
*/
@SuppressWarnings( "serial" )
// use default serial UID
public class JsonArray extends JsonValue implements Iterable {
private final List values;
/**
* Creates a new empty JsonArray.
*/
public JsonArray() {
values = new ArrayList();
}
/**
* Creates a new JsonArray with the contents of the specified JSON array.
*
* @param array
* the JsonArray to get the initial contents from, must not be null
*/
public JsonArray( JsonArray array ) {
this( array, false );
}
private JsonArray( JsonArray array, boolean unmodifiable ) {
if( array == null ) {
throw new NullPointerException( "array is null" );
}
if( unmodifiable ) {
values = Collections.unmodifiableList( array.values );
} else {
values = new ArrayList( array.values );
}
}
/**
* Reads a JSON array from the given reader.
*
* Characters are read in chunks and buffered internally, therefore wrapping an existing reader in
* an additional BufferedReader does not improve reading
* performance.
*
*
* @param reader
* the reader to read the JSON array from
* @return the JSON array that has been read
* @throws IOException
* if an I/O error occurs in the reader
* @throws ParseException
* if the input is not valid JSON
* @throws UnsupportedOperationException
* if the input does not contain a JSON array
*/
public static JsonArray readFrom( Reader reader ) throws IOException {
return JsonValue.readFrom( reader ).asArray();
}
/**
* Reads a JSON array from the given string.
*
* @param string
* the string that contains the JSON array
* @return the JSON array that has been read
* @throws ParseException
* if the input is not valid JSON
* @throws UnsupportedOperationException
* if the input does not contain a JSON array
*/
public static JsonArray readFrom( String string ) {
return JsonValue.readFrom( string ).asArray();
}
/**
* Returns an unmodifiable wrapper for the specified JsonArray. This method allows to provide
* read-only access to a JsonArray.
*
* The returned JsonArray is backed by the given array and reflects subsequent changes. Attempts
* to modify the returned JsonArray result in an UnsupportedOperationException.
*
*
* @param array
* the JsonArray for which an unmodifiable JsonArray is to be returned
* @return an unmodifiable view of the specified JsonArray
*/
public static JsonArray unmodifiableArray( JsonArray array ) {
return new JsonArray( array, true );
}
/**
* Appends the JSON representation of the specified int value to the end of this
* array.
*
* @param value
* the value to add to the array
* @return the array itself, to enable method chaining
*/
public JsonArray add( int value ) {
values.add( valueOf( value ) );
return this;
}
/**
* Appends the JSON representation of the specified long value to the end of this
* array.
*
* @param value
* the value to add to the array
* @return the array itself, to enable method chaining
*/
public JsonArray add( long value ) {
values.add( valueOf( value ) );
return this;
}
/**
* Appends the JSON representation of the specified float value to the end of this
* array.
*
* @param value
* the value to add to the array
* @return the array itself, to enable method chaining
*/
public JsonArray add( float value ) {
values.add( valueOf( value ) );
return this;
}
/**
* Appends the JSON representation of the specified double value to the end of this
* array.
*
* @param value
* the value to add to the array
* @return the array itself, to enable method chaining
*/
public JsonArray add( double value ) {
values.add( valueOf( value ) );
return this;
}
/**
* Appends the JSON representation of the specified boolean value to the end of this
* array.
*
* @param value
* the value to add to the array
* @return the array itself, to enable method chaining
*/
public JsonArray add( boolean value ) {
values.add( valueOf( value ) );
return this;
}
/**
* Appends the JSON representation of the specified string to the end of this array.
*
* @param value
* the string to add to the array
* @return the array itself, to enable method chaining
*/
public JsonArray add( String value ) {
values.add( valueOf( value ) );
return this;
}
/**
* Appends the specified JSON value to the end of this array.
*
* @param value
* the JsonValue to add to the array, must not be null
* @return the array itself, to enable method chaining
*/
public JsonArray add( JsonValue value ) {
if( value == null ) {
throw new NullPointerException( "value is null" );
}
values.add( value );
return this;
}
/**
* Replaces the element at the specified position in this array with the JSON representation of
* the specified int value.
*
* @param index
* the index of the array element to replace
* @param value
* the value to be stored at the specified array position
* @return the array itself, to enable method chaining
* @throws IndexOutOfBoundsException
* if the index is out of range, i.e. index < 0 or
* index >= size
*/
public JsonArray set( int index, int value ) {
values.set( index, valueOf( value ) );
return this;
}
/**
* Replaces the element at the specified position in this array with the JSON representation of
* the specified long value.
*
* @param index
* the index of the array element to replace
* @param value
* the value to be stored at the specified array position
* @return the array itself, to enable method chaining
* @throws IndexOutOfBoundsException
* if the index is out of range, i.e. index < 0 or
* index >= size
*/
public JsonArray set( int index, long value ) {
values.set( index, valueOf( value ) );
return this;
}
/**
* Replaces the element at the specified position in this array with the JSON representation of
* the specified float value.
*
* @param index
* the index of the array element to replace
* @param value
* the value to be stored at the specified array position
* @return the array itself, to enable method chaining
* @throws IndexOutOfBoundsException
* if the index is out of range, i.e. index < 0 or
* index >= size
*/
public JsonArray set( int index, float value ) {
values.set( index, valueOf( value ) );
return this;
}
/**
* Replaces the element at the specified position in this array with the JSON representation of
* the specified double value.
*
* @param index
* the index of the array element to replace
* @param value
* the value to be stored at the specified array position
* @return the array itself, to enable method chaining
* @throws IndexOutOfBoundsException
* if the index is out of range, i.e. index < 0 or
* index >= size
*/
public JsonArray set( int index, double value ) {
values.set( index, valueOf( value ) );
return this;
}
/**
* Replaces the element at the specified position in this array with the JSON representation of
* the specified boolean value.
*
* @param index
* the index of the array element to replace
* @param value
* the value to be stored at the specified array position
* @return the array itself, to enable method chaining
* @throws IndexOutOfBoundsException
* if the index is out of range, i.e. index < 0 or
* index >= size
*/
public JsonArray set( int index, boolean value ) {
values.set( index, valueOf( value ) );
return this;
}
/**
* Replaces the element at the specified position in this array with the JSON representation of
* the specified string.
*
* @param index
* the index of the array element to replace
* @param value
* the string to be stored at the specified array position
* @return the array itself, to enable method chaining
* @throws IndexOutOfBoundsException
* if the index is out of range, i.e. index < 0 or
* index >= size
*/
public JsonArray set( int index, String value ) {
values.set( index, valueOf( value ) );
return this;
}
/**
* Replaces the element at the specified position in this array with the specified JSON value.
*
* @param index
* the index of the array element to replace
* @param value
* the value to be stored at the specified array position, must not be null
* @return the array itself, to enable method chaining
* @throws IndexOutOfBoundsException
* if the index is out of range, i.e. index < 0 or
* index >= size
*/
public JsonArray set( int index, JsonValue value ) {
if( value == null ) {
throw new NullPointerException( "value is null" );
}
values.set( index, value );
return this;
}
/**
* Removes the element at the specified index from this array.
*
* @param index
* the index of the element to remove
* @return the array itself, to enable method chaining
* @throws IndexOutOfBoundsException
* if the index is out of range, i.e. index < 0 or
* index >= size
*/
public JsonArray remove( int index ) {
values.remove( index );
return this;
}
/**
* Returns the number of elements in this array.
*
* @return the number of elements in this array
*/
public int size() {
return values.size();
}
/**
* Returns true if this array contains no elements.
*
* @return true if this array contains no elements
*/
public boolean isEmpty() {
return values.isEmpty();
}
/**
* Returns the value of the element at the specified position in this array.
*
* @param index
* the index of the array element to return
* @return the value of the element at the specified position
* @throws IndexOutOfBoundsException
* if the index is out of range, i.e. index < 0 or
* index >= size
*/
public JsonValue get( int index ) {
return values.get( index );
}
/**
* Returns a list of the values in this array in document order. The returned list is backed by
* this array and will reflect subsequent changes. It cannot be used to modify this array.
* Attempts to modify the returned list will result in an exception.
*
* @return a list of the values in this array
*/
public List values() {
return Collections.unmodifiableList( values );
}
/**
* Returns an iterator over the values of this array in document order. The returned iterator
* cannot be used to modify this array.
*
* @return an iterator over the values of this array
*/
public Iterator iterator() {
final Iterator iterator = values.iterator();
return new Iterator() {
public boolean hasNext() {
return iterator.hasNext();
}
public JsonValue next() {
return iterator.next();
}
public void remove() {
throw new UnsupportedOperationException();
}
};
}
@Override
protected void write( JsonWriter writer ) throws IOException {
writer.writeArray( this );
}
@Override
public boolean isArray() {
return true;
}
@Override
public JsonArray asArray() {
return this;
}
@Override
public int hashCode() {
return values.hashCode();
}
@Override
public boolean equals( Object object ) {
if( this == object ) {
return true;
}
if( object == null ) {
return false;
}
if( getClass() != object.getClass() ) {
return false;
}
JsonArray other = (JsonArray)object;
return values.equals( other.values );
}
}