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/*
* Copyright (c) 2016 Couchbase, Inc.
*
* 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.couchbase.columnar.client.java.json;
import com.couchbase.client.core.deps.com.fasterxml.jackson.core.JsonProcessingException;
import com.couchbase.columnar.client.java.internal.JacksonTransformers;
import reactor.util.annotation.Nullable;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import static java.util.Objects.requireNonNull;
/**
* Represents a JSON object that can be stored and loaded from Couchbase Server.
*
* If boxed return values are unboxed, the calling code needs to make sure to handle potential
* {@link NullPointerException}s.
*
* The {@link JsonObject} is backed by a {@link Map} and is intended to work similar to it API wise, but to only
* allow to store such objects which can be represented by JSON.
*/
@SuppressWarnings("unused")
public final class JsonObject extends JsonValue {
/**
* The backing {@link Map} for the object.
*/
private final Map content;
/**
* Private constructor to create the object.
*
* The internal map is initialized with the default capacity.
*/
private JsonObject() {
content = new HashMap<>();
}
/**
* Private constructor to create the object with a custom initial capacity.
*/
private JsonObject(int initialCapacity) {
content = new HashMap<>(initialCapacity);
}
/**
* Creates an empty {@link JsonObject}.
*
* @return an empty {@link JsonObject}.
*/
public static JsonObject create() {
return new JsonObject();
}
/**
* Creates an empty {@link JsonObject}.
*
* @param initialCapacity the initial capacity for the object.
* @return an empty {@link JsonObject}.
*/
public static JsonObject create(int initialCapacity) {
return new JsonObject(initialCapacity);
}
/**
* Constructs a {@link JsonObject} from a {@link Map Map<String, ?>}.
*
* This is only possible if the given Map is well-formed, that is it contains non-null
* keys, and all values are of a supported type.
*
* A null input Map or null key will lead to a {@link NullPointerException} being thrown.
* If any unsupported value is present in the Map, an {@link IllegalArgumentException}
* will be thrown.
*
* *Sub Maps and Lists*
* If possible, Maps and Lists contained in mapData will be converted to JsonObject and
* JsonArray respectively. However, same restrictions apply. Any non-convertible collection
* will raise a {@link ClassCastException}. If the sub-conversion raises an exception (like an
* InvalidArgumentException) then it is put as cause for the ClassCastException.
*
* @param mapData the Map to convert to a JsonObject
* @return the resulting JsonObject
* @throws IllegalArgumentException in case one or more unsupported values are present
* @throws NullPointerException in case a null map is provided or if it contains a null key
* @throws ClassCastException if map contains a sub-Map or sub-List not supported (see above)
*/
public static JsonObject from(final Map mapData) {
requireNonNull(mapData, "Null input Map unsupported");
JsonObject result = new JsonObject(mapData.size());
try {
mapData.forEach((key, value) -> {
requireNonNull(key, "The key is not allowed to be null");
result.put(key, coerce(value));
});
} catch (ClassCastException e) {
throw new IllegalArgumentException("Map key must be String", e);
}
return result;
}
/**
* Static method to create a {@link JsonObject} from a JSON {@link String}.
*
* The string is expected to be a valid JSON object representation (eg. starting with a '{').
*
* @param jsonObject the JSON String to convert to a {@link JsonObject}.
* @return the corresponding {@link JsonObject}.
* @throws IllegalArgumentException if the conversion cannot be done.
*/
public static JsonObject fromJson(final String jsonObject) {
try {
return JacksonTransformers.MAPPER.readValue(jsonObject, JsonObject.class);
} catch (Exception e) {
throw new IllegalArgumentException("Cannot convert string to JsonObject", e);
}
}
public static JsonObject fromJson(final byte[] jsonObject) {
try {
return JacksonTransformers.MAPPER.readValue(jsonObject, JsonObject.class);
} catch (Exception e) {
throw new IllegalArgumentException("Cannot convert byte array to JsonObject", e);
}
}
/**
* Stores a {@link Object} value identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
* @throws IllegalArgumentException if the value is not a supported JSON type
*/
public JsonObject put(final String name, @Nullable final Object value) {
if (this == value) {
throw new IllegalArgumentException("Cannot put self");
}
content.put(name, coerce(value));
return this;
}
/**
* Retrieves the (potential null) content and not casting its type.
*
* @param name the key of the field.
* @return the value of the field, or null if it does not exist.
*/
@Nullable
public Object get(final String name) {
return content.get(name);
}
/**
* Stores a {@link String} value identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
*/
public JsonObject put(final String name, @Nullable final String value) {
content.put(name, value);
return this;
}
/**
* Retrieves the value from the field name and casts it to {@link String}.
*
* @param name the name of the field.
* @return the result or null if it does not exist.
*/
@Nullable
public String getString(String name) {
return (String) content.get(name);
}
/**
* Stores a {@link Integer} value identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
*/
public JsonObject put(String name, int value) {
content.put(name, value);
return this;
}
/**
* Retrieves the value from the field name and casts it to {@link Integer}.
*
* Note that if value was stored as another numerical type, some truncation or rounding may occur.
*
* @param name the name of the field.
* @return the result or null if it does not exist.
*/
@Nullable
public Integer getInt(String name) {
//let it fail in the more general case where it isn't actually a number
Number number = (Number) content.get(name);
if (number == null) {
return null;
} else if (number instanceof Integer) {
return (Integer) number;
} else {
return number.intValue(); //autoboxing to Integer
}
}
/**
* Stores a {@link Long} value identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
*/
public JsonObject put(String name, long value) {
content.put(name, value);
return this;
}
/**
* Retrieves the value from the field name and casts it to {@link Long}.
*
* Note that if value was stored as another numerical type, some truncation or rounding may occur.
*
* @param name the name of the field.
* @return the result or null if it does not exist.
*/
@Nullable
public Long getLong(String name) {
//let it fail in the more general case where it isn't actually a number
Number number = (Number) content.get(name);
if (number == null) {
return null;
} else if (number instanceof Long) {
return (Long) number;
} else {
return number.longValue(); //autoboxing to Long
}
}
/**
* Stores a {@link Double} value identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
*/
public JsonObject put(String name, double value) {
content.put(name, value);
return this;
}
/**
* Retrieves the value from the field name and casts it to {@link Double}.
*
* Note that if value was stored as another numerical type, some truncation or rounding may occur.
*
* @param name the name of the field.
* @return the result or null if it does not exist.
*/
@Nullable
public Double getDouble(String name) {
//let it fail in the more general case where it isn't actually a number
Number number = (Number) content.get(name);
if (number == null) {
return null;
} else if (number instanceof Double) {
return (Double) number;
} else {
return number.doubleValue(); //autoboxing to Double
}
}
/**
* Stores a {@link Boolean} value identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
*/
public JsonObject put(String name, boolean value) {
content.put(name, value);
return this;
}
/**
* Retrieves the value from the field name and casts it to {@link Boolean}.
*
* @param name the name of the field.
* @return the result or null if it does not exist.
*/
@Nullable
public Boolean getBoolean(String name) {
return (Boolean) content.get(name);
}
/**
* Stores a {@link JsonObject} value identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
*/
public JsonObject put(String name, @Nullable JsonObject value) {
if (this == value) {
throw new IllegalArgumentException("Cannot put self");
}
content.put(name, value);
return this;
}
/**
* Attempt to convert a {@link Map} to a {@link JsonObject} value and store it, identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
* @see #from(Map)
*/
public JsonObject put(String name, @Nullable Map value) {
return put(name, value == null ? null : JsonObject.from(value));
}
/**
* Retrieves the value from the field name and casts it to {@link JsonObject}.
*
* @param name the name of the field.
* @return the result or null if it does not exist.
*/
@Nullable
public JsonObject getObject(String name) {
return (JsonObject) content.get(name);
}
/**
* Stores a {@link JsonArray} value identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
*/
public JsonObject put(String name, @Nullable JsonArray value) {
content.put(name, value);
return this;
}
/**
* Stores a {@link Number} value identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
*/
public JsonObject put(String name, @Nullable Number value) {
content.put(name, value);
return this;
}
/**
* Stores a {@link JsonArray} value identified by the field name.
*
* @param name the name of the JSON field.
* @param value the value of the JSON field.
* @return the {@link JsonObject}.
*/
public JsonObject put(String name, @Nullable List value) {
return put(name, value == null ? null : JsonArray.from(value));
}
/**
* Retrieves the value from the field name and casts it to {@link JsonArray}.
*
* @param name the name of the field.
* @return the result or null if it does not exist.
*/
@Nullable
public JsonArray getArray(String name) {
return (JsonArray) content.get(name);
}
/**
* Retrieves the value from the field name and casts it to {@link BigInteger}.
*
* @param name the name of the field.
* @return the result or null if it does not exist.
*/
@Nullable
public BigInteger getBigInteger(String name) {
return (BigInteger) content.get(name);
}
/**
* Retrieves the value from the field name and casts it to {@link BigDecimal}.
*
* @param name the name of the field.
* @return the result or null if it does not exist.
*/
@Nullable
public BigDecimal getBigDecimal(String name) {
Object found = content.get(name);
if (found == null) {
return null;
} else if (found instanceof Double) {
return BigDecimal.valueOf((Double) found);
}
return (BigDecimal) found;
}
/**
* Retrieves the value from the field name and casts it to {@link Number}.
*
* @param name the name of the field.
* @return the result or null if it does not exist.
*/
@Nullable
public Number getNumber(String name) {
return (Number) content.get(name);
}
/**
* Store a null value identified by the field's name.
*
* This method is equivalent to calling {@link #put(String, Object)} with
* a null value explicitly cast to Object.
*
* @param name The null field's name.
* @return the {@link JsonObject}
*/
public JsonObject putNull(String name) {
content.put(name, null);
return this;
}
/**
* Removes an entry from the {@link JsonObject}.
*
* @param name the name of the field to remove
* @return the {@link JsonObject}
*/
public JsonObject removeKey(String name) {
content.remove(name);
return this;
}
/**
* Returns a set of field names on the {@link JsonObject}.
*
* @return the set of names on the object.
*/
public Set getNames() {
return content.keySet();
}
/**
* Returns true if the {@link JsonObject} is empty, false otherwise.
*
* @return true if empty, false otherwise.
*/
public boolean isEmpty() {
return content.isEmpty();
}
/**
* Transforms the {@link JsonObject} into a {@link Map}. The resulting
* map is not backed by this {@link JsonObject}, and all sub-objects or
* sub-arrays ({@link JsonArray}) are also recursively converted to
* maps and lists, respectively.
*
* @return the content copied as a {@link Map}.
*/
public Map toMap() {
Map copy = new HashMap<>(content.size());
for (Map.Entry entry : content.entrySet()) {
Object content = entry.getValue();
if (content instanceof JsonObject) {
copy.put(entry.getKey(), ((JsonObject) content).toMap());
} else if (content instanceof JsonArray) {
copy.put(entry.getKey(), ((JsonArray) content).toList());
} else {
copy.put(entry.getKey(), content);
}
}
return copy;
}
/**
* Checks if the {@link JsonObject} contains the field name.
*
* @param name the name of the field.
* @return true if its contained, false otherwise.
*/
public boolean containsKey(String name) {
return content.containsKey(name);
}
/**
* Checks if the {@link JsonObject} contains the value.
*
* @param value the actual value.
* @return true if its contained, false otherwise.
*/
public boolean containsValue(Object value) {
return content.containsValue(value);
}
/**
* The size of the {@link JsonObject}.
*
* @return the size.
*/
public int size() {
return content.size();
}
/**
* Converts the {@link JsonObject} into its JSON string representation.
*
* @return the JSON string representing this {@link JsonObject}.
*/
@Override
public String toString() {
try {
return JacksonTransformers.MAPPER.writeValueAsString(this);
} catch (JsonProcessingException e) {
throw new RuntimeException("Cannot convert JsonObject to Json String", e);
}
}
/**
* Similar to {@link #toString()} but turns this object directly into an encoded byte array.
*
* @return the byte array representing this {@link JsonObject}.
*/
public byte[] toBytes() {
try {
return JacksonTransformers.MAPPER.writeValueAsBytes(this);
} catch (JsonProcessingException e) {
throw new RuntimeException("Cannot convert JsonObject to Json byte array", e);
}
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
JsonObject that = (JsonObject) o;
return Objects.equals(content, that.content);
}
@Override
public int hashCode() {
return Objects.hash(content);
}
}