1 /*
2  * Copyright (C) 2022 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.adservices.service.common;
18 
19 import android.annotation.NonNull;
20 
21 import org.json.JSONArray;
22 import org.json.JSONException;
23 import org.json.JSONObject;
24 
25 import java.util.Objects;
26 
27 /** Utility class that contains functions to more easily interact with {@link JSONObject}. */
28 public class JsonUtils {
29     public static final String VALUE_NOT_A_STRING = "Value with key %s is not a String!";
30     /**
31      * Gets a string value from a {@code JSONObject} with key {@code key} without forcing the value
32      * of {@link JSONObject#getString(String)} into a String
33      *
34      * @throws JSONException if {@code key} is not in {@code JSONObject} or value of {@code
35      *     JSONObject.getString(key)} is not a String
36      */
37     @NonNull
getStringFromJson(@onNull JSONObject jsonObject, @NonNull String key)38     public static String getStringFromJson(@NonNull JSONObject jsonObject, @NonNull String key)
39             throws JSONException {
40         return getStringFromJson(jsonObject, key, String.format(VALUE_NOT_A_STRING, key));
41     }
42 
43     /**
44      * Gets a string value from a {@code JSONArray} with index {@code index} without forcing the
45      * value of {@link JSONObject#getString(String)} into a String. The caller can provide a custom
46      * error message that will be set in the JSONException if a failure occurs.
47      *
48      * @throws JSONException if {@code key} is not in {@code JSONObject} or value of {@code
49      *     JSONObject.getString(key)} is not a String
50      */
51     @NonNull
getStringFromJsonArrayAtIndex( @onNull JSONArray jsonArray, int index, @NonNull String errorMsg)52     public static String getStringFromJsonArrayAtIndex(
53             @NonNull JSONArray jsonArray, int index, @NonNull String errorMsg)
54             throws JSONException {
55         Objects.requireNonNull(jsonArray);
56         Objects.requireNonNull(errorMsg);
57 
58         return assertObjectIsString(jsonArray.get(index), errorMsg);
59     }
60 
61     /**
62      * Gets a string value from a {@code JSONObject} with key {@code key} without forcing the value
63      * of {@link JSONObject#getString(String)} into a String. The caller can provide a custom error
64      * message that will be set in the JSONException if a failure occurs.
65      *
66      * @throws JSONException if {@code key} is not in {@code JSONObject} or value of {@code
67      *     JSONObject.getString(key)} is not a String
68      */
69     @NonNull
getStringFromJson( @onNull JSONObject jsonObject, @NonNull String key, @NonNull String errorMsg)70     public static String getStringFromJson(
71             @NonNull JSONObject jsonObject, @NonNull String key, @NonNull String errorMsg)
72             throws JSONException {
73         Objects.requireNonNull(jsonObject);
74         Objects.requireNonNull(key);
75         Objects.requireNonNull(errorMsg);
76 
77         return assertObjectIsString(jsonObject.get(key), errorMsg);
78     }
79 
assertObjectIsString(Object o, String errorMsg)80     private static String assertObjectIsString(Object o, String errorMsg) throws JSONException {
81         if (!(o instanceof String)) {
82             throw new JSONException(errorMsg);
83         }
84         return (String) o;
85     }
86 }
87