JSONObjectUtils.java
/*
* nimbus-jose-jwt
*
* Copyright 2012-2016, Connect2id Ltd.
*
* 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.nimbusds.jose.util;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.ToNumberPolicy;
import com.google.gson.internal.LinkedTreeMap;
import com.google.gson.reflect.TypeToken;
import java.lang.reflect.Type;
import java.net.URI;
import java.net.URISyntaxException;
import java.text.ParseException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* JSON object helper methods.
*
* @author Vladimir Dzhuvinov
* @version 2022-08-19
*/
public class JSONObjectUtils {
/**
* The GSon instance for serialisation and parsing.
*/
private static final Gson GSON = new GsonBuilder()
.serializeNulls()
.setObjectToNumberStrategy(ToNumberPolicy.LONG_OR_DOUBLE)
.disableHtmlEscaping()
.create();
/**
* 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 java.util.List<Object>}.
* <li>JSON objects map to {@code java.util.Map<String,Object>}.
* </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 Map<String, Object> parse(final String s)
throws ParseException {
return parse(s, -1);
}
/**
* Parses a JSON object with the option to limit the input string size.
*
* <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 java.util.List<Object>}.
* <li>JSON objects map to {@code java.util.Map<String,Object>}.
* </ul>
*
* @param s The JSON object string to parse. Must not be
* {@code null}.
* @param sizeLimit The max allowed size of the string to parse. A
* negative integer means no limit.
*
* @return The JSON object.
*
* @throws ParseException If the string cannot be parsed to a valid JSON
* object.
*/
public static Map<String, Object> parse(final String s, final int sizeLimit)
throws ParseException {
if (s.trim().isEmpty()) {
throw new ParseException("Invalid JSON object", 0);
}
if (sizeLimit >= 0 && s.length() > sizeLimit) {
throw new ParseException("The parsed string is longer than the max accepted size of " + sizeLimit + " characters", 0);
}
Type mapType = TypeToken.getParameterized(Map.class, String.class, Object.class).getType();
try {
return GSON.fromJson(s, mapType);
} catch (Exception e) {
throw new ParseException("Invalid JSON: " + e.getMessage(), 0);
} catch (StackOverflowError e) {
throw new ParseException("Excessive JSON object and / or array nesting", 0);
}
}
/**
* Use {@link #parse(String)} instead.
*
* @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.
*/
@Deprecated
public static Map<String, Object> parseJSONObject(final String s)
throws ParseException {
return parse(s);
}
/**
* 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, may be {@code null}.
*
* @throws ParseException If the value is not of the expected type.
*/
private static <T> T getGeneric(final Map<String, Object> o, final String key, final Class<T> clazz)
throws ParseException {
if (o.get(key) == null) {
return null;
}
Object value = o.get(key);
if (! clazz.isAssignableFrom(value.getClass())) {
throw new ParseException("Unexpected type of JSON object member with key " + key + "", 0);
}
@SuppressWarnings("unchecked")
T castValue = (T)value;
return castValue;
}
/**
* 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 JSON object member value.
*
* @throws ParseException If the member is missing, the value is
* {@code null} or not of the expected type.
*/
public static boolean getBoolean(final Map<String, Object> o, final String key)
throws ParseException {
Boolean value = getGeneric(o, key, Boolean.class);
if (value == null) {
throw new ParseException("JSON object member with key " + key + " is missing or null", 0);
}
return value;
}
/**
* 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 JSON object member value.
*
* @throws ParseException If the member is missing, the value is
* {@code null} or not of the expected type.
*/
public static int getInt(final Map<String, Object> o, final String key)
throws ParseException {
Number value = getGeneric(o, key, Number.class);
if (value == null) {
throw new ParseException("JSON object member with key " + key + " is missing or null", 0);
}
return value.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 JSON object member value.
*
* @throws ParseException If the member is missing, the value is
* {@code null} or not of the expected type.
*/
public static long getLong(final Map<String, Object> o, final String key)
throws ParseException {
Number value = getGeneric(o, key, Number.class);
if (value == null) {
throw new ParseException("JSON object member with key " + key + " is missing or null", 0);
}
return value.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 JSON object member value, may be {@code null}.
*
* @throws ParseException If the member is missing, the value is
* {@code null} or not of the expected type.
*/
public static float getFloat(final Map<String, Object> o, final String key)
throws ParseException {
Number value = getGeneric(o, key, Number.class);
if (value == null) {
throw new ParseException("JSON object member with key " + key + " is missing or null", 0);
}
return value.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 JSON object member value, may be {@code null}.
*
* @throws ParseException If the member is missing, the value is
* {@code null} or not of the expected type.
*/
public static double getDouble(final Map<String, Object> o, final String key)
throws ParseException {
Number value = getGeneric(o, key, Number.class);
if (value == null) {
throw new ParseException("JSON object member with key " + key + " is missing or null", 0);
}
return value.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 JSON object member value, may be {@code null}.
*
* @throws ParseException If the value is not of the expected type.
*/
public static String getString(final Map<String, Object> o, final String key)
throws ParseException {
return getGeneric(o, key, String.class);
}
/**
* Gets a string member of a JSON object as {@code java.net.URI}.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The JSON object member value, may be {@code null}.
*
* @throws ParseException If the value is not of the expected type.
*/
public static URI getURI(final Map<String, Object> o, final String key)
throws ParseException {
String value = getString(o, key);
if (value == null) {
return null;
}
try {
return new URI(value);
} catch (URISyntaxException 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 JSON object member value, may be {@code null}.
*
* @throws ParseException If the value is not of the expected type.
*/
public static List<Object> getJSONArray(final Map<String, Object> o, final String key)
throws ParseException {
@SuppressWarnings("unchecked")
List<Object> jsonArray = getGeneric(o, key, List.class);
return jsonArray;
}
/**
* 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 JSON object member value, may be {@code null}.
*
* @throws ParseException If the value is not of the expected type.
*/
public static String[] getStringArray(final Map<String, Object> o, final String key)
throws ParseException {
List<Object> jsonArray = getJSONArray(o, key);
if (jsonArray == null) {
return null;
}
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 JSON objects 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 JSON object member value, may be {@code null}.
*
* @throws ParseException If the value is not of the expected type.
*/
public static Map<String, Object>[] getJSONObjectArray(final Map<String, Object> o, final String key)
throws ParseException {
List<Object> jsonArray = getJSONArray(o, key);
if (jsonArray == null) {
return null;
}
if (jsonArray.isEmpty()) {
return new HashMap[0];
}
for (Object member: jsonArray) {
if (member == null) {
continue;
}
if (member instanceof HashMap) {
try {
return jsonArray.toArray(new HashMap[0]);
} catch (ArrayStoreException e) {
break; // throw parse exception below
}
}
if (member instanceof LinkedTreeMap) {
try {
return jsonArray.toArray(new LinkedTreeMap[0]);
} catch (ArrayStoreException e) {
break; // throw parse exception below
}
}
}
throw new ParseException("JSON object member with key \"" + key + "\" is not an array of JSON objects", 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 JSON object member value, may be {@code null}.
*
* @throws ParseException If the value is not of the expected type.
*/
public static List<String> getStringList(final Map<String, Object> o, final String key) throws ParseException {
String[] array = getStringArray(o, key);
if (array == null) {
return null;
}
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 JSON object member value, may be {@code null}.
*
* @throws ParseException If the value is not of the expected type.
*/
public static Map<String, Object> getJSONObject(final Map<String, Object> o, final String key)
throws ParseException {
Map<?,?> jsonObject = getGeneric(o, key, Map.class);
if (jsonObject == null) {
return null;
}
// Verify keys are String
for (Object oKey: jsonObject.keySet()) {
if (! (oKey instanceof String)) {
throw new ParseException("JSON object member with key " + key + " not a JSON object", 0);
}
}
@SuppressWarnings("unchecked")
Map<String, Object> castJSONObject = (Map<String, Object>)jsonObject;
return castJSONObject;
}
/**
* Gets a string member of a JSON object as {@link Base64URL}.
*
* @param o The JSON object. Must not be {@code null}.
* @param key The JSON object member key. Must not be {@code null}.
*
* @return The JSON object member value, may be {@code null}.
*
* @throws ParseException If the value is not of the expected type.
*/
public static Base64URL getBase64URL(final Map<String, Object> o, final String key)
throws ParseException {
String value = getString(o, key);
if (value == null) {
return null;
}
return new Base64URL(value);
}
/**
* Serialises the specified map to a JSON object using the entity
* mapping specified in {@link #parse(String)}.
*
* @param o The map. Must not be {@code null}.
*
* @return The JSON object as string.
*/
public static String toJSONString(final Map<String, ?> o) {
return GSON.toJson(o);
}
/**
* Creates a new JSON object (unordered).
*
* @return The new empty JSON object.
*/
public static Map<String, Object> newJSONObject() {
return new HashMap<>();
}
/**
* Prevents public instantiation.
*/
private JSONObjectUtils() { }
}