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Panda Core is the core module of Panda Framework, it contains commonly used utility classes similar to apache-commons.
package panda.bind.json;
import java.io.InputStream;
import java.io.Reader;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import panda.io.stream.CharSequenceReader;
/**
* A JsonObject is an unordered collection of name/value pairs. Its external
* form is a string wrapped in curly braces with colons between the names and
* values, and commas between the values and names. The internal form is an
* object having get and opt methods for accessing
* the values by name, and put methods for adding or replacing
* values by name. The values can be any of these types: Boolean,
* JSONArray, JsonObject, Number,
* String, or the JsonObject.NULL object. A
* JsonObject constructor can be used to convert an external form JSON text
* into an internal form whose values can be retrieved with the
* get and opt methods, or to convert values into a
* JSON text using the put and toString methods. A
* get method returns a value if one can be found, and throws an
* exception if one cannot be found. An opt method returns a
* default value instead of throwing an exception, and so is useful for
* obtaining optional values.
*
* The generic get() and opt() methods return an
* object, which you can cast or query for type. There are also typed
* get and opt methods that do type checking and type
* coercion for you. The opt methods differ from the get methods in that they
* do not throw. Instead, they return a specified value, such as null.
*
* The put methods add or replace values in an object. For
* example,
*
*
* myString = new JsonObject()
* .put("JSON", "Hello, World!").toString();
*
*
* produces the string {"JSON": "Hello, World"}.
*
* The texts produced by the toString methods strictly conform to
* the JSON syntax rules. The constructors are more forgiving in the texts they
* will accept:
*
* - An extra
, (comma) may appear just
* before the closing brace.
* - Strings may be quoted with
' (single
* quote).
* - Strings do not need to be quoted at all if they do not begin with a
* quote or single quote, and if they do not contain leading or trailing
* spaces, and if they do not contain any of these characters:
*
{ } [ ] / \ : , # and if they do not look like numbers and
* if they are not the reserved words true, false,
* or null.
*
*
* @see JSON.org
*/
public class JsonObject extends LinkedHashMap {
/**
* serialVersionUID
*/
private static final long serialVersionUID = 1L;
/**
* Construct an empty JsonObject.
*/
public JsonObject() {
super();
}
/**
* @param initialCapacity the initial capacity
* @param loadFactor the load factor
*/
public JsonObject(int initialCapacity, float loadFactor) {
super(initialCapacity, loadFactor);
}
/**
* @param initialCapacity the initial capacity
*/
public JsonObject(int initialCapacity) {
super(initialCapacity);
}
/**
* Construct a JsonObject from a subset of another JsonObject. An array of strings is used to
* identify the keys that should be copied. Missing keys are ignored.
*
* @param jo A JsonObject.
* @param names An array of strings.
* @exception JsonException If a value is a non-finite number or if a name is duplicated.
*/
public JsonObject(JsonObject jo, String[] names) {
for (int i = 0; i < names.length; i += 1) {
this.set(names[i], jo.opt(names[i]));
}
}
/**
* Construct a JsonObject from a Map.
*
* @param map A map object that can be used to initialize the contents of the JsonObject.
*/
public JsonObject(Map map) {
if (map != null) {
for (java.util.Map.Entry en : map.entrySet()) {
this.set(en.getKey().toString(), en.getValue());
}
}
}
/**
* Accumulate values under a key. It is similar to the put method except that if there is
* already an object stored under the key then a JSONArray is stored under the key to hold all
* of the accumulated values. If there is already a JSONArray, then the new value is appended to
* it. In contrast, the put method replaces the previous value. If only one value is accumulated
* that is not a JSONArray, then the result will be the same as using put. But if multiple
* values are accumulated, then the result will be like append.
*
* @param key A key string.
* @param value An object to be accumulated under the key.
* @return this.
* @throws JsonException If the value is an invalid number or if the key is null.
*/
public JsonObject accumulate(String key, Object value) throws JsonException {
Object object = this.opt(key);
if (object == null) {
this.set(key, value);
}
else if (object instanceof JsonArray) {
((JsonArray)object).put(value);
}
else {
this.put(key, new JsonArray().put(object).put(value));
}
return this;
}
public JsonObject accumulateAll(Map map) throws JsonException {
for (java.util.Map.Entry en : map.entrySet()) {
accumulate(en.getKey(), en.getValue());
}
return this;
}
/**
* Append values to the array under a key. If the key does not exist in the JsonObject, then the
* key is put in the JsonObject with its value being a JSONArray containing the value parameter.
* If the key was already associated with a JSONArray, then the value parameter is appended to
* it.
*
* @param key A key string.
* @param value An object to be accumulated under the key.
* @return this.
* @throws JsonException If the key is null or if the current value associated with the key is
* not a JSONArray.
*/
public JsonObject append(String key, Object value) throws JsonException {
Object object = this.opt(key);
if (object == null) {
this.put(key, new JsonArray().put(value));
}
else if (object instanceof JsonArray) {
((JsonArray)object).put(value);
}
else {
throw new JsonException("JsonObject[" + key + "] is not a JSONArray.");
}
return this;
}
/**
* Get the value object associated with a key.
*
* @param key A key string.
* @return The object associated with the key.
* @throws JsonException if the key is not found.
*/
public Object get(String key) throws JsonException {
if (key == null) {
throw new JsonException("Null key.");
}
Object object = super.get(key);
if (object == null) {
throw new JsonException("JsonObject[" + key + "] not found.");
}
return object;
}
/**
* Get the boolean value associated with a key.
*
* @param key A key string.
* @return The truth.
* @throws JsonException if the value is not a Boolean.
*/
public boolean getBoolean(String key) throws JsonException {
Object object = this.get(key);
if (object instanceof Boolean) {
return ((Boolean)object).booleanValue();
}
throw new JsonException("JsonObject[" + key + "] is not a Boolean.");
}
/**
* Get the double value associated with a key.
*
* @param key A key string.
* @return The numeric value.
* @throws JsonException if the key is not found or if the value is not a Number object
*/
public double getDouble(String key) throws JsonException {
Object object = this.get(key);
if (object instanceof Number) {
return ((Number)object).doubleValue();
}
throw new JsonException("JsonObject[" + key + "] is not a number.");
}
/**
* Get the float value associated with a key.
*
* @param key A key string.
* @return The numeric value.
* @throws JsonException if the key is not found or if the value is not a Number object
*/
public float getFloat(String key) throws JsonException {
Object object = this.get(key);
if (object instanceof Number) {
return ((Number)object).floatValue();
}
throw new JsonException("JsonObject[" + key + "] is not a number.");
}
/**
* Get the int value associated with a key.
*
* @param key A key string.
* @return The integer value.
* @throws JsonException if the key is not found or if the value is not a Number object
*/
public int getInt(String key) throws JsonException {
Object object = this.get(key);
if (object instanceof Number) {
return ((Number)object).intValue();
}
throw new JsonException("JsonObject[" + key + "] is not a number.");
}
/**
* Get the JSONArray value associated with a key.
*
* @param key A key string.
* @return A JSONArray which is the value.
* @throws JsonException if the key is not found or if the value is not a JSONArray.
*/
public JsonArray getJsonArray(String key) throws JsonException {
Object object = this.get(key);
if (object instanceof JsonArray) {
return (JsonArray)object;
}
throw new JsonException("JsonObject[" + key + "] is not a JsonArray.");
}
/**
* Get the JsonObject value associated with a key.
*
* @param key A key string.
* @return A JsonObject which is the value.
* @throws JsonException if the key is not found or if the value is not a JsonObject.
*/
public JsonObject getJsonObject(String key) throws JsonException {
Object object = this.get(key);
if (object instanceof JsonObject) {
return (JsonObject)object;
}
throw new JsonException("JsonObject[" + key + "] is not a JsonObject.");
}
/**
* Get the long value associated with a key.
*
* @param key A key string.
* @return The long value.
* @throws JsonException if the key is not found or if the value is not a Number object
*/
public long getLong(String key) throws JsonException {
Object object = this.get(key);
if (object instanceof Number) {
return ((Number)object).longValue();
}
throw new JsonException("JsonObject[" + key + "] is not a number.");
}
/**
* Get the string associated with a key.
*
* @param key A key string.
* @return A string which is the value.
* @throws JsonException if there is no string value for the key.
*/
public String getString(String key) throws JsonException {
Object object = this.get(key);
if (object instanceof String) {
return (String)object;
}
throw new JsonException("JsonObject[" + key + "] not a string.");
}
/**
* Determine if the JsonObject contains a specific key.
*
* @param key A key string.
* @return true if the key exists in the JsonObject.
*/
public boolean has(String key) {
return this.containsKey(key);
}
/**
* Increment a property of a JsonObject. If there is no such property, create one with a value
* of 1. If there is such a property, and if it is an Integer, Long, Double, or Float, then add
* one to it.
*
* @param key A key string.
* @return this.
* @throws JsonException If there is already a property with this name that is not an Integer,
* Long, Double, or Float.
*/
public JsonObject increment(String key) throws JsonException {
Object value = this.opt(key);
if (value == null) {
this.set(key, 1);
}
else if (value instanceof Short) {
this.set(key, ((Short)value).shortValue() + 1);
}
else if (value instanceof Integer) {
this.set(key, ((Integer)value).intValue() + 1);
}
else if (value instanceof Long) {
this.set(key, ((Long)value).longValue() + 1);
}
else if (value instanceof Double) {
this.set(key, ((Double)value).doubleValue() + 1);
}
else if (value instanceof Float) {
this.set(key, ((Float)value).floatValue() + 1);
}
else {
throw new JsonException("Unable to increment [" + key + "].");
}
return this;
}
/**
* Determine if the value associated with the key is null or if there is no value.
*
* @param key A key string.
* @return true if there is no value associated with the key or if the value is null.
*/
public boolean isNull(String key) {
return null == this.opt(key);
}
/**
* Get an enumeration of the keys of the JsonObject.
*
* @return An iterator of the keys.
*/
public Iterator keys() {
return this.keySet().iterator();
}
/**
* Get the number of keys stored in the JsonObject.
*
* @return The number of keys in the JsonObject.
*/
public int length() {
return this.size();
}
/**
* Produce a JSONArray containing the names of the elements of this JsonObject.
*
* @return A JSONArray containing the key strings, or null if the JsonObject is empty.
*/
public JsonArray names() {
JsonArray ja = new JsonArray();
Iterator keys = this.keys();
while (keys.hasNext()) {
ja.put(keys.next());
}
return ja.length() == 0 ? null : ja;
}
/**
* Get an optional value associated with a key.
*
* @param key A key string.
* @return An object which is the value, or null if there is no value.
*/
public Object opt(String key) {
if (key == null) {
return null;
}
return super.get(key);
}
/**
* Get an optional boolean associated with a key. It returns false if there is no such key, or
* if the value is not Boolean.TRUE.
*
* @param key A key string.
* @return The truth.
*/
public boolean optBoolean(String key) {
return this.optBoolean(key, false);
}
/**
* Get an optional boolean associated with a key. It returns the defaultValue if there is no
* such key, or if it is not a Boolean.
*
* @param key A key string.
* @param defaultValue The default.
* @return The truth.
*/
public boolean optBoolean(String key, boolean defaultValue) {
Object object = this.opt(key);
if (object instanceof Boolean) {
return ((Boolean)object).booleanValue();
}
return defaultValue;
}
/**
* Get an optional double associated with a key, or NaN if there is no such key or if its value
* is not a number.
*
* @param key A string which is the key.
* @return An object which is the value.
*/
public double optDouble(String key) {
return this.optDouble(key, Double.NaN);
}
/**
* Get an optional double associated with a key, or the defaultValue if there is no such key or
* if its value is not a number.
*
* @param key A key string.
* @param defaultValue The default.
* @return An object which is the value.
*/
public double optDouble(String key, double defaultValue) {
Object object = this.opt(key);
if (object instanceof Number) {
return ((Number)object).doubleValue();
}
return defaultValue;
}
/**
* Get an optional float associated with a key, or NaN if there is no such key or if its value
* is not a number.
*
* @param key A string which is the key.
* @return An object which is the value.
*/
public float optFloat(String key) {
return this.optFloat(key, Float.NaN);
}
/**
* Get an optional float associated with a key, or the defaultValue if there is no such key or
* if its value is not a number.
*
* @param key A key string.
* @param defaultValue The default.
* @return An object which is the value.
*/
public float optFloat(String key, float defaultValue) {
Object object = this.opt(key);
if (object instanceof Number) {
return ((Number)object).floatValue();
}
return defaultValue;
}
/**
* Get an optional int value associated with a key, or zero if there is no such key or if the
* value is not a number.
*
* @param key A key string.
* @return An object which is the value.
*/
public int optInt(String key) {
return this.optInt(key, 0);
}
/**
* Get an optional int value associated with a key, or the default if there is no such key or if
* the value is not a number.
*
* @param key A key string.
* @param defaultValue The default.
* @return An object which is the value.
*/
public int optInt(String key, int defaultValue) {
Object object = this.opt(key);
if (object instanceof Number) {
return ((Number)object).intValue();
}
return defaultValue;
}
/**
* Get an optional JSONArray associated with a key. It returns null if there is no such key, or
* if its value is not a JSONArray.
*
* @param key A key string.
* @return A JSONArray which is the value.
*/
public JsonArray optJsonArray(String key) {
Object o = this.opt(key);
return o instanceof JsonArray ? (JsonArray)o : null;
}
/**
* Get an optional JsonObject associated with a key. It returns null if there is no such key, or
* if its value is not a JsonObject.
*
* @param key A key string.
* @return A JsonObject which is the value.
*/
public JsonObject optJsonObject(String key) {
Object object = this.opt(key);
return object instanceof JsonObject ? (JsonObject)object : null;
}
/**
* Get an optional long value associated with a key, or zero if there is no such key or if the
* value is not a number.
*
* @param key A key string.
* @return An object which is the value.
*/
public long optLong(String key) {
return this.optLong(key, 0);
}
/**
* Get an optional long value associated with a key, or the default if there is no such key or
* if the value is not a number.
*
* @param key A key string.
* @param defaultValue The default.
* @return An object which is the value.
*/
public long optLong(String key, long defaultValue) {
Object object = this.opt(key);
if (object instanceof Number) {
return ((Number)object).longValue();
}
return defaultValue;
}
/**
* Get an optional string associated with a key. It returns null if there is no such
* key or if the value is not a string.
*
* @param key A key string.
* @return A string which is the value.
*/
public String optString(String key) {
return optString(key, null);
}
/**
* Get an optional string associated with a key. It returns the defaultValue if there is no such
* key or if the value is not a string.
*
* @param key A key string.
* @param defaultValue The default.
* @return A string which is the value.
*/
public String optString(String key, String defaultValue) {
Object object = this.opt(key);
if (object instanceof String) {
return (String)object;
}
return defaultValue;
}
/**
* Put a key/boolean pair in the JsonObject.
*
* @param key A key string.
* @param value A boolean which is the value.
* @return this.
* @throws JsonException If the key is null.
*/
public JsonObject set(String key, boolean value) throws JsonException {
this.put(key, value ? Boolean.TRUE : Boolean.FALSE);
return this;
}
/**
* Put a key/value pair in the JsonObject, where the value will be a JSONArray which is produced
* from a Collection.
*
* @param key A key string.
* @param value A Collection value.
* @return this.
* @throws JsonException if the value is invalid
*/
public JsonObject set(String key, Collection value) throws JsonException {
this.put(key, new JsonArray(value));
return this;
}
/**
* Put a key/double pair in the JsonObject.
*
* @param key A key string.
* @param value A double which is the value.
* @return this.
* @throws JsonException If the key is null or if the number is invalid.
*/
public JsonObject set(String key, double value) throws JsonException {
this.put(key, new Double(value));
return this;
}
/**
* Put a key/float pair in the JsonObject.
*
* @param key A key string.
* @param value A float which is the value.
* @return this.
* @throws JsonException If the key is null or if the number is invalid.
*/
public JsonObject set(String key, float value) throws JsonException {
this.put(key, new Float(value));
return this;
}
/**
* Put a key/int pair in the JsonObject.
*
* @param key A key string.
* @param value An int which is the value.
* @return this.
* @throws JsonException If the key is null.
*/
public JsonObject set(String key, int value) throws JsonException {
this.put(key, new Integer(value));
return this;
}
/**
* Put a key/long pair in the JsonObject.
*
* @param key A key string.
* @param value A long which is the value.
* @return this.
* @throws JsonException If the key is null.
*/
public JsonObject set(String key, long value) throws JsonException {
this.put(key, new Long(value));
return this;
}
/**
* Put a key/value pair in the JsonObject, where the value will be a JsonObject which is
* produced from a Map.
*
* @param key A key string.
* @param value A Map value.
* @return this.
* @throws JsonException if the value is invalid
*/
public JsonObject set(String key, Map value) throws JsonException {
this.put(key, new JsonObject(value));
return this;
}
/**
* Put a key/value pair in the JsonObject. If the value is null, then the key will be removed
* from the JsonObject if it is present.
*
* @param key A key string.
* @param value An object which is the value. It should be of one of these types: Boolean,
* Double, Integer, JSONArray, JsonObject, Long, String, or the JsonObject.NULL
* object.
* @return this.
* @throws JsonException If the value is non-finite number or if the key is null.
*/
public JsonObject set(String key, Object value) throws JsonException {
this.put(key, value);
return this;
}
/**
* Put a key/value pair in the JsonObject, but only if the key and the value are both non-null.
*
* @param key A key string.
* @param value An object which is the value. It should be of one of these types: Boolean,
* Double, Integer, JSONArray, JsonObject, Long, String, or the JsonObject.NULL
* object.
* @return this.
* @throws JsonException If the value is a non-finite number.
*/
public JsonObject setOpt(String key, Object value) throws JsonException {
if (key != null) {
this.set(key, value);
}
return this;
}
/**
* {@inheritDoc}
*/
@Override
public Object put(String key, Object value) {
if (key == null) {
throw new NullPointerException("Null key.");
}
return super.put(key, wrap(value));
}
/**
* Wrap an object, if necessary. If the object is null, return the NULL object. If it is an
* array or collection, wrap it in a JSONArray. If it is a map, wrap it in a JsonObject. If it
* is a standard property (Double, String, et al) then it is already wrapped. Otherwise, if it
* comes from one of the java packages, turn it into a string. And if it doesn't, try to wrap it
* in a JsonObject. If the wrapping fails, then null is returned.
*
* @param object The object to wrap
* @return The wrapped value
*/
protected static Object wrap(Object object) {
if (object == null) {
return null;
}
if (object instanceof JsonObject || object instanceof JsonArray
|| object instanceof String || object instanceof Character
|| object instanceof Boolean || object instanceof Number) {
return object;
}
if (object instanceof Collection) {
return new JsonArray((Collection)object);
}
if (object.getClass().isArray()) {
return new JsonArray(object);
}
if (object instanceof Map) {
return new JsonObject((Map)object);
}
throw new JsonException("Invalid argument: " + object.getClass());
}
/**
* {@inheritDoc}
*/
public String toString() {
return Jsons.toJson(this);
}
public String toString(boolean pretty) {
return Jsons.toJson(this, pretty);
}
public String toString(int indent) {
return Jsons.toJson(this, indent);
}
public static JsonObject fromJson(InputStream json) {
return Jsons.fromJson(json, JsonObject.class);
}
public static JsonObject fromJson(InputStream json, String encoding) {
return Jsons.fromJson(json, encoding, JsonObject.class);
}
public static JsonObject fromJson(Reader json) {
return Jsons.fromJson(json, JsonObject.class);
}
public static JsonObject fromJson(CharSequence json) {
if (json == null) {
return null;
}
JsonTokener jt = new JsonTokener(new CharSequenceReader(json));
char c = jt.nextClean();
if (c != '{') {
json = "{" + json + "}";
}
return Jsons.fromJson(json, JsonObject.class);
}
}