/*
* Copyright (C) 2010 The Android Open Source Project
*
* 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 org.json;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
// Note: this class was written without inspecting the non-free org.json sourcecode.
/**
* A dense indexed sequence of values. Values may be any mix of
* {@link JSONObject JSONObjects}, other {@link JSONArray JSONArrays}, Strings,
* Booleans, Integers, Longs, Doubles, {@code null} or {@link JSONObject#NULL}.
* Values may not be {@link Double#isNaN() NaNs}, {@link Double#isInfinite()
* infinities}, or of any type not listed here.
*
* <p>{@code JSONArray} has the same type coercion behavior and
* optional/mandatory accessors as {@link JSONObject}. See that class'
* documentation for details.
*
* <p><strong>Warning:</strong> this class represents null in two incompatible
* ways: the standard Java {@code null} reference, and the sentinel value {@link
* JSONObject#NULL}. In particular, {@code get} fails if the requested index
* holds the null reference, but succeeds if it holds {@code JSONObject.NULL}.
*
* <p>Instances of this class are not thread safe. Although this class is
* nonfinal, it was not designed for inheritance and should not be subclassed.
* In particular, self-use by overridable methods is not specified. See
* <i>Effective Java</i> Item 17, "Design and Document or inheritance or else
* prohibit it" for further information.
*/
public class JSONArray {
private final List<Object> values;
/**
* Creates a {@code JSONArray} with no values.
*/
public JSONArray() {
values = new ArrayList<Object>();
}
/**
* Creates a new {@code JSONArray} by copying all values from the given
* collection.
*
* @param copyFrom a collection whose values are of supported types.
* Unsupported values are not permitted and will yield an array in an
* inconsistent state.
*/
/* Accept a raw type for API compatibility */
public JSONArray(Collection copyFrom) {
this();
Collection<?> copyFromTyped = (Collection<?>) copyFrom;
values.addAll(copyFromTyped);
}
/**
* Creates a new {@code JSONArray} with values from the next array in the
* tokener.
*
* @param readFrom a tokener whose nextValue() method will yield a
* {@code JSONArray}.
* @throws JSONException if the parse fails or doesn't yield a
* {@code JSONArray}.
*/
public JSONArray(JSONTokener readFrom) throws JSONException {
/*
* Getting the parser to populate this could get tricky. Instead, just
* parse to temporary JSONArray and then steal the data from that.
*/
Object object = readFrom.nextValue();
if (object instanceof JSONArray) {
values = ((JSONArray) object).values;
} else {
throw JSON.typeMismatch(object, "JSONArray");
}
}
/**
* Creates a new {@code JSONArray} with values from the JSON string.
*
* @param json a JSON-encoded string containing an array.
* @throws JSONException if the parse fails or doesn't yield a {@code
* JSONArray}.
*/
public JSONArray(String json) throws JSONException {
this(new JSONTokener(json));
}
/**
* Returns the number of values in this array.
*/
public int length() {
return values.size();
}
/**
* Appends {@code value} to the end of this array.
*
* @return this array.
*/
public JSONArray put(boolean value) {
values.add(value);
return this;
}
/**
* Appends {@code value} to the end of this array.
*
* @param value a finite value. May not be {@link Double#isNaN() NaNs} or
* {@link Double#isInfinite() infinities}.
* @return this array.
*/
public JSONArray put(double value) throws JSONException {
values.add(JSON.checkDouble(value));
return this;
}
/**
* Appends {@code value} to the end of this array.
*
* @return this array.
*/
public JSONArray put(int value) {
values.add(value);
return this;
}
/**
* Appends {@code value} to the end of this array.
*
* @return this array.
*/
public JSONArray put(long value) {
values.add(value);
return this;
}
/**
* Appends {@code value} to the end of this array.
*
* @param value a {@link JSONObject}, {@link JSONArray}, String, Boolean,
* Integer, Long, Double, {@link JSONObject#NULL}, or {@code null}. May
* not be {@link Double#isNaN() NaNs} or {@link Double#isInfinite()
* infinities}. Unsupported values are not permitted and will cause the
* array to be in an inconsistent state.
* @return this array.
*/
public JSONArray put(Object value) {
values.add(value);
return this;
}
/**
* Sets the value at {@code index} to {@code value}, null padding this array
* to the required length if necessary. If a value already exists at {@code
* index}, it will be replaced.
*
* @return this array.
*/
public JSONArray put(int index, boolean value) throws JSONException {
return put(index, (Boolean) value);
}
/**
* Sets the value at {@code index} to {@code value}, null padding this array
* to the required length if necessary. If a value already exists at {@code
* index}, it will be replaced.
*
* @param value a finite value. May not be {@link Double#isNaN() NaNs} or
* {@link Double#isInfinite() infinities}.
* @return this array.
*/
public JSONArray put(int index, double value) throws JSONException {
return put(index, (Double) value);
}
/**
* Sets the value at {@code index} to {@code value}, null padding this array
* to the required length if necessary. If a value already exists at {@code
* index}, it will be replaced.
*
* @return this array.
*/
public JSONArray put(int index, int value) throws JSONException {
return put(index, (Integer) value);
}
/**
* Sets the value at {@code index} to {@code value}, null padding this array
* to the required length if necessary. If a value already exists at {@code
* index}, it will be replaced.
*
* @return this array.
*/
public JSONArray put(int index, long value) throws JSONException {
return put(index, (Long) value);
}
/**
* Sets the value at {@code index} to {@code value}, null padding this array
* to the required length if necessary. If a value already exists at {@code
* index}, it will be replaced.
*
* @param value a {@link JSONObject}, {@link JSONArray}, String, Boolean,
* Integer, Long, Double, {@link JSONObject#NULL}, or {@code null}. May
* not be {@link Double#isNaN() NaNs} or {@link Double#isInfinite()
* infinities}.
* @return this array.
*/
public JSONArray put(int index, Object value) throws JSONException {
if (value instanceof Number) {
// deviate from the original by checking all Numbers, not just floats & doubles
JSON.checkDouble(((Number) value).doubleValue());
}
while (values.size() <= index) {
values.add(null);
}
values.set(index, value);
return this;
}
/**
* Returns true if this array has no value at {@code index}, or if its value
* is the {@code null} reference or {@link JSONObject#NULL}.
*/
public boolean isNull(int index) {
Object value = opt(index);
return value == null || value == JSONObject.NULL;
}
/**
* Returns the value at {@code index}.
*
* @throws JSONException if this array has no value at {@code index}, or if
* that value is the {@code null} reference. This method returns
* normally if the value is {@code JSONObject#NULL}.
*/
public Object get(int index) throws JSONException {
try {
Object value = values.get(index);
if (value == null) {
throw new JSONException("Value at " + index + " is null.");
}
return value;
} catch (IndexOutOfBoundsException e) {
throw new JSONException("Index " + index + " out of range [0.." + values.size() + ")");
}
}
/**
* Returns the value at {@code index}, or null if the array has no value
* at {@code index}.
*/
public Object opt(int index) {
if (index < 0 || index >= values.size()) {
return null;
}
return values.get(index);
}
/**
* Returns the value at {@code index} if it exists and is a boolean or can
* be coerced to a boolean.
*
* @throws JSONException if the value at {@code index} doesn't exist or
* cannot be coerced to a boolean.
*/
public boolean getBoolean(int index) throws JSONException {
Object object = get(index);
Boolean result = JSON.toBoolean(object);
if (result == null) {
throw JSON.typeMismatch(index, object, "boolean");
}
return result;
}
/**
* Returns the value at {@code index} if it exists and is a boolean or can
* be coerced to a boolean. Returns false otherwise.
*/
public boolean optBoolean(int index) {
return optBoolean(index, false);
}
/**
* Returns the value at {@code index} if it exists and is a boolean or can
* be coerced to a boolean. Returns {@code fallback} otherwise.
*/
public boolean optBoolean(int index, boolean fallback) {
Object object = opt(index);
Boolean result = JSON.toBoolean(object);
return result != null ? result : fallback;
}
/**
* Returns the value at {@code index} if it exists and is a double or can
* be coerced to a double.
*
* @throws JSONException if the value at {@code index} doesn't exist or
* cannot be coerced to a double.
*/
public double getDouble(int index) throws JSONException {
Object object = get(index);
Double result = JSON.toDouble(object);
if (result == null) {
throw JSON.typeMismatch(index, object, "double");
}
return result;
}
/**
* Returns the value at {@code index} if it exists and is a double or can
* be coerced to a double. Returns {@code NaN} otherwise.
*/
public double optDouble(int index) {
return optDouble(index, Double.NaN);
}
/**
* Returns the value at {@code index} if it exists and is a double or can
* be coerced to a double. Returns {@code fallback} otherwise.
*/
public double optDouble(int index, double fallback) {
Object object = opt(index);
Double result = JSON.toDouble(object);
return result != null ? result : fallback;
}
/**
* Returns the value at {@code index} if it exists and is an int or
* can be coerced to an int.
*
* @throws JSONException if the value at {@code index} doesn't exist or
* cannot be coerced to a int.
*/
public int getInt(int index) throws JSONException {
Object object = get(index);
Integer result = JSON.toInteger(object);
if (result == null) {
throw JSON.typeMismatch(index, object, "int");
}
return result;
}
/**
* Returns the value at {@code index} if it exists and is an int or
* can be coerced to an int. Returns 0 otherwise.
*/
public int optInt(int index) {
return optInt(index, 0);
}
/**
* Returns the value at {@code index} if it exists and is an int or
* can be coerced to an int. Returns {@code fallback} otherwise.
*/
public int optInt(int index, int fallback) {
Object object = opt(index);
Integer result = JSON.toInteger(object);
return result != null ? result : fallback;
}
/**
* Returns the value at {@code index} if it exists and is a long or
* can be coerced to a long.
*
* @throws JSONException if the value at {@code index} doesn't exist or
* cannot be coerced to a long.
*/
public long getLong(int index) throws JSONException {
Object object = get(index);
Long result = JSON.toLong(object);
if (result == null) {
throw JSON.typeMismatch(index, object, "long");
}
return result;
}
/**
* Returns the value at {@code index} if it exists and is a long or
* can be coerced to a long. Returns 0 otherwise.
*/
public long optLong(int index) {
return optLong(index, 0L);
}
/**
* Returns the value at {@code index} if it exists and is a long or
* can be coerced to a long. Returns {@code fallback} otherwise.
*/
public long optLong(int index, long fallback) {
Object object = opt(index);
Long result = JSON.toLong(object);
return result != null ? result : fallback;
}
/**
* Returns the value at {@code index} if it exists, coercing it if
* necessary.
*
* @throws JSONException if no such value exists.
*/
public String getString(int index) throws JSONException {
Object object = get(index);
String result = JSON.toString(object);
if (result == null) {
throw JSON.typeMismatch(index, object, "String");
}
return result;
}
/**
* Returns the value at {@code index} if it exists, coercing it if
* necessary. Returns the empty string if no such value exists.
*/
public String optString(int index) {
return optString(index, "");
}
/**
* Returns the value at {@code index} if it exists, coercing it if
* necessary. Returns {@code fallback} if no such value exists.
*/
public String optString(int index, String fallback) {
Object object = opt(index);
String result = JSON.toString(object);
return result != null ? result : fallback;
}
/**
* Returns the value at {@code index} if it exists and is a {@code
* JSONArray}.
*
* @throws JSONException if the value doesn't exist or is not a {@code
* JSONArray}.
*/
public JSONArray getJSONArray(int index) throws JSONException {
Object object = get(index);
if (object instanceof JSONArray) {
return (JSONArray) object;
} else {
throw JSON.typeMismatch(index, object, "JSONArray");
}
}
/**
* Returns the value at {@code index} if it exists and is a {@code
* JSONArray}. Returns null otherwise.
*/
public JSONArray optJSONArray(int index) {
Object object = opt(index);
return object instanceof JSONArray ? (JSONArray) object : null;
}
/**
* Returns the value at {@code index} if it exists and is a {@code
* JSONObject}.
*
* @throws JSONException if the value doesn't exist or is not a {@code
* JSONObject}.
*/
public JSONObject getJSONObject(int index) throws JSONException {
Object object = get(index);
if (object instanceof JSONObject) {
return (JSONObject) object;
} else {
throw JSON.typeMismatch(index, object, "JSONObject");
}
}
/**
* Returns the value at {@code index} if it exists and is a {@code
* JSONObject}. Returns null otherwise.
*/
public JSONObject optJSONObject(int index) {
Object object = opt(index);
return object instanceof JSONObject ? (JSONObject) object : null;
}
/**
* Returns a new object whose values are the values in this array, and whose
* names are the values in {@code names}. Names and values are paired up by
* index from 0 through to the shorter array's length. Names that are not
* strings will be coerced to strings. This method returns null if either
* array is empty.
*/
public JSONObject toJSONObject(JSONArray names) throws JSONException {
JSONObject result = new JSONObject();
int length = Math.min(names.length(), values.size());
if (length == 0) {
return null;
}
for (int i = 0; i < length; i++) {
String name = JSON.toString(names.opt(i));
result.put(name, opt(i));
}
return result;
}
/**
* Returns a new string by alternating this array's values with {@code
* separator}. This array's string values are quoted and have their special
* characters escaped. For example, the array containing the strings '12"
* pizza', 'taco' and 'soda' joined on '+' returns this:
* <pre>"12\" pizza"+"taco"+"soda"</pre>
*/
public String join(String separator) throws JSONException {
JSONStringer stringer = new JSONStringer();
stringer.open(JSONStringer.Scope.NULL, "");
for (int i = 0, size = values.size(); i < size; i++) {
if (i > 0) {
stringer.out.append(separator);
}
stringer.value(values.get(i));
}
stringer.close(JSONStringer.Scope.NULL, JSONStringer.Scope.NULL, "");
return stringer.out.toString();
}
/**
* Encodes this array as a compact JSON string, such as:
* <pre>[94043,90210]</pre>
*/
@Override public String toString() {
try {
JSONStringer stringer = new JSONStringer();
writeTo(stringer);
return stringer.toString();
} catch (JSONException e) {
return null;
}
}
/**
* Encodes this array as a human readable JSON string for debugging, such
* as:
* <pre>
* [
* 94043,
* 90210
* ]</pre>
*
* @param indentSpaces the number of spaces to indent for each level of
* nesting.
*/
public String toString(int indentSpaces) throws JSONException {
JSONStringer stringer = new JSONStringer(indentSpaces);
writeTo(stringer);
return stringer.toString();
}
void writeTo(JSONStringer stringer) throws JSONException {
stringer.array();
for (Object value : values) {
stringer.value(value);
}
stringer.endArray();
}
@Override public boolean equals(Object o) {
return o instanceof JSONArray && ((JSONArray) o).values.equals(values);
}
@Override public int hashCode() {
// diverge from the original, which doesn't implement hashCode
return values.hashCode();
}
}