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* Copyright (c) 2015, 2016 EclipseSource.
*
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* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
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* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* SOFTWARE.
******************************************************************************/
package com.blade.kit.json;
import java.io.IOException;
import java.io.Reader;
/**
* This class serves as the entry point to the minimal-json API.
* <p>
* To <strong>parse</strong> a given JSON input, use the <code>parse()</code>
* methods like in this example:
* </p>
*
* <pre>
* JsonObject object = Json.parse(string).asObject();
* </pre>
* <p>
* To <strong>create</strong> a JSON data structure to be serialized, use the
* methods <code>value()</code>, <code>array()</code>, and <code>object()</code>
* . For example, the following snippet will produce the JSON string
* <em>{"foo": 23, "bar": true}</em>:
* </p>
*
* <pre>
* String string = Json.object().add("foo", 23).add("bar", true).toString();
* </pre>
* <p>
* To create a JSON array from a given Java array, you can use one of the
* <code>array()</code> methods with varargs parameters:
* </p>
*
* <pre>
* String[] names = ...
* JsonArray array = Json.array(names);
* </pre>
*/
public final class JSON {
private JSON() {
// not meant to be instantiated
}
/**
* Represents the JSON literal <code>null</code>.
*/
public static final JSONValue NULL = new JSONLiteral("null");
/**
* Represents the JSON literal <code>true</code>.
*/
public static final JSONValue TRUE = new JSONLiteral("true");
/**
* Represents the JSON literal <code>false</code>.
*/
public static final JSONValue FALSE = new JSONLiteral("false");
/**
* Returns a JsonValue instance that represents the given <code>int</code>
* value.
*
* @param value
* the value to get a JSON representation for
* @return a JSON value that represents the given value
*/
public static JSONValue value(Integer value) {
return new JSONNumber(Integer.toString(value, 10));
}
public static JSONValue value(Object value) {
return JSONHelper.toJSONValue(value);
}
/**
* Returns a JsonValue instance that represents the given <code>long</code>
* value.
*
* @param value
* the value to get a JSON representation for
* @return a JSON value that represents the given value
*/
public static JSONValue value(Long value) {
return new JSONNumber(Long.toString(value, 10));
}
public static JSONValue value(Byte value) {
return new JSONNumber(Byte.toString(value));
}
/**
* Returns a JsonValue instance that represents the given <code>float</code>
* value.
*
* @param value
* the value to get a JSON representation for
* @return a JSON value that represents the given value
*/
public static JSONValue value(Float value) {
if (Float.isInfinite(value) || Float.isNaN(value)) {
throw new IllegalArgumentException("Infinite and NaN values not permitted in JSON");
}
return new JSONNumber(cutOffPointZero(Float.toString(value)));
}
/**
* Returns a JsonValue instance that represents the given
* <code>double</code> value.
*
* @param value
* the value to get a JSON representation for
* @return a JSON value that represents the given value
*/
public static JSONValue value(Double value) {
if (Double.isInfinite(value) || Double.isNaN(value)) {
throw new IllegalArgumentException("Infinite and NaN values not permitted in JSON");
}
return new JSONNumber(cutOffPointZero(Double.toString(value)));
}
/**
* Returns a JsonValue instance that represents the given string.
*
* @param string
* the string to get a JSON representation for
* @return a JSON value that represents the given string
*/
public static JSONValue value(String string) {
return string == null ? NULL : new JSONString(string);
}
/**
* Returns a JsonValue instance that represents the given
* <code>boolean</code> value.
*
* @param value
* the value to get a JSON representation for
* @return a JSON value that represents the given value
*/
public static JSONValue value(Boolean value) {
return value ? TRUE : FALSE;
}
/**
* Creates a new empty JsonArray. This is equivalent to creating a new
* JsonArray using the constructor.
*
* @return a new empty JSON array
*/
public static JSONValue array() {
return new JSONArray();
}
/**
* Creates a new JsonArray that contains the JSON representations of the
* given <code>int</code> values.
*
* @param values
* the values to be included in the new JSON array
* @return a new JSON array that contains the given values
*/
public static JSONArray array(Integer... values) {
if (values == null) {
throw new NullPointerException("values is null");
}
JSONArray array = new JSONArray();
for (int value : values) {
array.add(value);
}
return array;
}
/**
* Creates a new JsonArray that contains the JSON representations of the
* given <code>long</code> values.
*
* @param values
* the values to be included in the new JSON array
* @return a new JSON array that contains the given values
*/
public static JSONArray array(Long... values) {
if (values == null) {
throw new NullPointerException("values is null");
}
JSONArray array = new JSONArray();
for (long value : values) {
array.add(value);
}
return array;
}
/**
* Creates a new JsonArray that contains the JSON representations of the
* given <code>float</code> values.
*
* @param values
* the values to be included in the new JSON array
* @return a new JSON array that contains the given values
*/
public static JSONArray array(Float... values) {
if (values == null) {
throw new NullPointerException("values is null");
}
JSONArray array = new JSONArray();
for (float value : values) {
array.add(value);
}
return array;
}
/**
* Creates a new JsonArray that contains the JSON representations of the
* given <code>double</code> values.
*
* @param values
* the values to be included in the new JSON array
* @return a new JSON array that contains the given values
*/
public static JSONArray array(Double... values) {
if (values == null) {
throw new NullPointerException("values is null");
}
JSONArray array = new JSONArray();
for (double value : values) {
array.add(value);
}
return array;
}
/**
* Creates a new JsonArray that contains the JSON representations of the
* given <code>boolean</code> values.
*
* @param values
* the values to be included in the new JSON array
* @return a new JSON array that contains the given values
*/
public static JSONArray array(Boolean... values) {
if (values == null) {
throw new NullPointerException("values is null");
}
JSONArray array = new JSONArray();
for (boolean value : values) {
array.add(value);
}
return array;
}
/**
* Creates a new JsonArray that contains the JSON representations of the
* given strings.
*
* @param strings
* the strings to be included in the new JSON array
* @return a new JSON array that contains the given strings
*/
public static JSONArray array(String... strings) {
if (strings == null) {
throw new NullPointerException("values is null");
}
JSONArray array = new JSONArray();
for (String value : strings) {
array.add(value);
}
return array;
}
/**
* Creates a new empty JsonObject. This is equivalent to creating a new
* JsonObject using the constructor.
*
* @return a new empty JSON object
*/
public static JSONObject create() {
return new JSONObject();
}
/**
* Parses the given input string as JSON. The input must contain a valid
* JSON value, optionally padded with whitespace.
*
* @param string
* the input string, must be valid JSON
* @return a value that represents the parsed JSON
* @throws ParseException
* if the input is not valid JSON
*/
public static JSONValue parse(String string) {
if (string == null) {
throw new NullPointerException("string is null");
}
DefaultHandler handler = new DefaultHandler();
new JSONParser(handler).parse(string);
return handler.getValue();
}
/**
* Reads the entire input from the given reader and parses it as JSON. The
* input must contain a valid JSON value, optionally padded with whitespace.
* <p>
* Characters are read in chunks into an input buffer. Hence, wrapping a
* reader in an additional <code>BufferedReader</code> likely won't improve
* reading performance.
* </p>
*
* @param reader
* the reader to read the JSON value from
* @return a value that represents the parsed JSON
* @throws IOException
* if an I/O error occurs in the reader
* @throws ParseException
* if the input is not valid JSON
*/
public static JSONValue parse(Reader reader) throws IOException {
if (reader == null) {
throw new NullPointerException("reader is null");
}
DefaultHandler handler = new DefaultHandler();
new JSONParser(handler).parse(reader);
return handler.getValue();
}
private static String cutOffPointZero(String string) {
if (string.endsWith(".0")) {
return string.substring(0, string.length() - 2);
}
return string;
}
static class DefaultHandler extends JSONHandler<JSONArray, JSONObject> {
protected JSONValue value;
@Override
public JSONArray startArray() {
return new JSONArray();
}
@Override
public JSONObject startObject() {
return new JSONObject();
}
@Override
public void endNull() {
value = NULL;
}
@Override
public void endBoolean(boolean bool) {
value = bool ? TRUE : FALSE;
}
@Override
public void endString(String string) {
value = new JSONString(string);
}
@Override
public void endNumber(String string) {
value = new JSONNumber(string);
}
@Override
public void endArray(JSONArray array) {
value = array;
}
@Override
public void endObject(JSONObject object) {
value = object;
}
@Override
public void endArrayValue(JSONArray array) {
array.add(value);
}
@Override
public void endObjectValue(JSONObject object, String name) {
object.put(name, value);
}
JSONValue getValue() {
return value;
}
}
}