package com.nimbusds.jose.util;
import java.net.MalformedURLException;
import java.net.URL;
import java.text.ParseException;
import java.util.Arrays;
import java.util.List;
import net.minidev.json.JSONArray;
import net.minidev.json.JSONObject;
import net.minidev.json.parser.JSONParser;
/**
* JSON object helper methods for parsing and typed retrieval of member values.
*
* @author Vladimir Dzhuvinov
* @version $version$ (2013-01-08)
*/
public class JSONObjectUtils {
/**
* Parses a JSON object.
*
* <p>Specific JSON to Java entity mapping (as per JSON Smart):
*
* <ul>
* <li>JSON true|false map to {@code java.lang.Boolean}.
* <li>JSON numbers map to {@code java.lang.Number}.
* <ul>
* <li>JSON integer numbers map to {@code long}.
* <li>JSON fraction numbers map to {@code double}.
* </ul>
* <li>JSON strings map to {@code java.lang.String}.
* <li>JSON arrays map to {@code net.minidev.json.JSONArray}.
* <li>JSON objects map to {@code net.minidev.json.JSONObject}.
* </ul>
*
* @param s The JSON object string to parse. Must not be {@code null}.
*
* @return The JSON object.
*
* @throws ParseException If the string cannot be parsed to a valid JSON
* object.
*/
public static JSONObject parseJSONObject(final String s)
throws ParseException {
Object o = null;
try {
o = new JSONParser(JSONParser.USE_HI_PRECISION_FLOAT).parse(s);
} catch (net.minidev.json.parser.ParseException e) {
throw new ParseException("Invalid JSON: " + e.getMessage(), 0);
}
if (o instanceof JSONObject) {
return (JSONObject)o;
} else {
throw new ParseException("JSON entity is not an object", 0);
}
}
/**
* Gets a generic member of a JSON object.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
* @param clazz The expected class of the JSON object member value. Must
* not be {@code null}.
*
* @return The JSON object member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
@SuppressWarnings("unchecked")
private static <T> T getGeneric(final JSONObject o, final String key, final Class<T> clazz)
throws ParseException {
if (! o.containsKey(key)) {
throw new ParseException("Missing JSON object member with key \"" + key + "\"", 0);
}
if (o.get(key) == null) {
throw new ParseException("JSON object member with key \"" + key + "\" has null value", 0);
}
Object value = o.get(key);
if (! clazz.isAssignableFrom(value.getClass())) {
throw new ParseException("Unexpected type of JSON object member with key \"" + key + "\"", 0);
}
return (T)value;
}
/**
* Gets a boolean member of a JSON object.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static boolean getBoolean(final JSONObject o, final String key)
throws ParseException {
return getGeneric(o, key, Boolean.class);
}
/**
* Gets an number member of a JSON object as {@code int}.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static int getInt(final JSONObject o, final String key)
throws ParseException {
return getGeneric(o, key, Number.class).intValue();
}
/**
* Gets a number member of a JSON object as {@code long}.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static long getLong(final JSONObject o, final String key)
throws ParseException {
return getGeneric(o, key, Number.class).longValue();
}
/**
* Gets a number member of a JSON object {@code float}.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static float getFloat(final JSONObject o, final String key)
throws ParseException {
return getGeneric(o, key, Number.class).floatValue();
}
/**
* Gets a number member of a JSON object as {@code double}.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static double getDouble(final JSONObject o, final String key)
throws ParseException {
return getGeneric(o, key, Number.class).doubleValue();
}
/**
* Gets a string member of a JSON object.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static String getString(final JSONObject o, final String key)
throws ParseException {
return getGeneric(o, key, String.class);
}
/**
* Gets a string member of a JSON object as {@code java.net.URL}.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static URL getURL(final JSONObject o, final String key)
throws ParseException {
try {
return new URL(getGeneric(o, key, String.class));
} catch (MalformedURLException e) {
throw new ParseException(e.getMessage(), 0);
}
}
/**
* Gets a JSON array member of a JSON object.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static JSONArray getJSONArray(final JSONObject o, final String key)
throws ParseException {
return getGeneric(o, key, JSONArray.class);
}
/**
* Gets a string array member of a JSON object.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static String[] getStringArray(final JSONObject o, final String key)
throws ParseException {
JSONArray jsonArray = getJSONArray(o, key);
try {
return jsonArray.toArray(new String[0]);
} catch (ArrayStoreException e) {
throw new ParseException("JSON object member with key \"" + key + "\" is not an array of strings", 0);
}
}
/**
* Gets a string list member of a JSON object
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static List<String> getStringList(final JSONObject o, final String key) throws ParseException {
String[] array = getStringArray(o, key);
return Arrays.asList(array);
}
/**
* Gets a JSON object member of a JSON object.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The member value.
*
* @throws ParseException If the value is missing, {@code null} or not
* of the expected type.
*/
public static JSONObject getJSONObject(final JSONObject o, final String key)
throws ParseException {
return getGeneric(o, key, JSONObject.class);
}
/**
* Prevents public instantiation.
*/
private JSONObjectUtils() {
// Nothing to do
}
}