JsonObject (cat-client 3.0.1 API)

java.lang.Object
- com.dianping.cat.util.json.JsonObject

```
public class JsonObject
extends Object
```
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.
The constructor can convert an external form string into an internal form Java object. The toString() method creates an external form string.
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 coersion for you.
The texts produced by the toString() methods are very strict. 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.
- Keys can be followed by = or => as well as by :
- Values can be followed by ; as well as by ,
- Numbers may have the 0- (octal) or 0x- (hex) prefix.
- Line comments can begin with #
版本:

1

作者:

JSON.org

字段概要

字段
限定符和类型字段和说明

static Object NULL
It is sometimes more convenient and less ambiguous to have a NULL object than to use Java's null value.

字段
限定符和类型	字段和说明
`static Object`	`NULL` It is sometimes more convenient and less ambiguous to have a NULL object than to use Java's null value.

构造器概要

构造器
构造器和说明
`JsonObject()` Construct an empty JSONObject.
`JsonObject(JsonObject jo, String[] sa)` Construct a JSONObject from a subset of another JSONObject.
`JsonObject(JsonTokener x)` Construct a JSONObject from a JSONTokener.
`JsonObject(Map<String,Object> map)` Construct a JSONObject from a Map.
`JsonObject(String string)` Construct a JSONObject from a string.

方法概要

所有方法静态方法实例方法具体方法
限定符和类型	方法和说明
`JsonObject`	`accumulate(String key, Object value)` Accumulate values under a key.
`StringBuilder`	`append(StringBuilder sb)` Appends this JsonObject to the provided string builder.
`protected static StringBuilder`	`appendQuoted(String str, StringBuilder sb)` Appends a string in double quotes with backslash sequences in all the right places.
`protected static StringBuilder`	`appendValue(Object value, StringBuilder sb)` Appends the given value to the provided string builder.
`static String`	`escape(String string)`
`static String`	`escape(String str, boolean singleQuote)`
`Object`	`get(String key)` Get the value object associated with a key.
`boolean`	`getBoolean(String key)` Get the boolean value associated with a key.
`double`	`getDouble(String key)` Get the double value associated with a key.
`int`	`getInt(String key)` Get the int value associated with a key.
`JsonArray`	`getJSONArray(String key)` Get the JSONArray value associated with a key.
`JsonObject`	`getJSONObject(String key)` Get the JSONObject value associated with a key.
`long`	`getLong(String key)` Get the long value associated with a key.
`protected static int`	`getQuotedSize(String str)` Returns an estimate of the size of the string in the quoted form.
`String`	`getString(String key)` Get the string associated with a key.
`protected static int`	`getValueSize(Object value)` Returns an estimate of the size of the value in a serialized form.
`boolean`	`has(String key)` Determine if the JSONObject contains a specific key.
`boolean`	`isNull(String key)` Determine if the value associated with the key is null or if there is no value.
`Iterator<String>`	`keys()` Get an enumeration of the keys of the JSONObject.
`int`	`length()` Get the number of keys stored in the JSONObject.
`JsonArray`	`names()` Produce a JSONArray containing the names of the elements of this JSONObject.
`static String`	`numberToString(Number n)` Produce a string from a number.
`Object`	`opt(String key)` Get an optional value associated with a key.
`boolean`	`optBoolean(String key)` Get an optional boolean associated with a key.
`boolean`	`optBoolean(String key, boolean defaultValue)` Get an optional boolean associated with a key.
`double`	`optDouble(String key)` Get an optional double associated with a key, or NaN if there is no such key or if its value is not a number.
`double`	`optDouble(String key, double defaultValue)` 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.
`int`	`optInt(String key)` 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.
`int`	`optInt(String key, int defaultValue)` 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.
`JsonArray`	`optJSONArray(String key)` Get an optional JSONArray associated with a key.
`JsonObject`	`optJSONObject(String key)` Get an optional JSONObject associated with a key.
`String`	`optString(String key)` Get an optional string associated with a key.
`String`	`optString(String key, String defaultValue)` Get an optional string associated with a key.
`JsonObject`	`put(String key, boolean value)` Put a key/boolean pair in the JSONObject.
`JsonObject`	`put(String key, double value)` Put a key/double pair in the JSONObject.
`JsonObject`	`put(String key, int value)` Put a key/int pair in the JSONObject.
`JsonObject`	`put(String key, Object value)` Put a key/value pair in the JSONObject.
`JsonObject`	`putOpt(String key, Object value)` Put a key/value pair in the JSONObject, but only if the value is non-null.
`static String`	`quote(String str)` Produce a string in double quotes with backslash sequences in all the right places.
`Object`	`remove(String key)` Remove a name and its value, if present.
`JsonArray`	`toJSONArray(JsonArray names)` Produce a JSONArray containing the values of the members of this JSONObject.
`String`	`toString()` Make an JSON external form string of this JSONObject.
`String`	`toString(int indentFactor)` Make a prettyprinted JSON external form string of this JSONObject.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- 字段详细资料
  - NULL
```
public static final Object NULL
```
    It is sometimes more convenient and less ambiguous to have a NULL object than to use Java's null value. JSONObject.NULL.equals(null) returns true. JSONObject.NULL.toString() returns "null".
- 构造器详细资料
  - JsonObject
```
public JsonObject()
```
    Construct an empty JSONObject.
  - JsonObject
```
public JsonObject(JsonObject jo,
                  String[] sa)
```
    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.
    
    参数:
    
    jo - A JSONObject.
    
    sa - An array of strings.
  - JsonObject
```
public JsonObject(JsonTokener x)
           throws ParseException
```
    Construct a JSONObject from a JSONTokener.
    
    参数:
    
    x - A JSONTokener object containing the source string.
    
    抛出:
    
    ParseException - if there is a syntax error in the source string.
  - JsonObject
```
public JsonObject(Map<String,Object> map)
```
    Construct a JSONObject from a Map.
    
    参数:
    
    map - A map object that can be used to initialize the contents of the JSONObject.
  - JsonObject
```
public JsonObject(String string)
           throws ParseException
```
    Construct a JSONObject from a string. This is the most commonly used JSONObject constructor.
    
    参数:
    
    string - A string beginning with { (left brace) and ending with } (right brace).
    
    抛出:
    
    ParseException - The string must be properly formatted.
- 方法详细资料
  - numberToString
```
public static String numberToString(Number n)
                             throws ArithmeticException
```
    Produce a string from a number.
    
    参数:
    
    n - A Number
    
    返回:
    
    A String.
    
    抛出:
    
    ArithmeticException - JSON can only serialize finite numbers.
  - quote
```
public static String quote(String str)
```
    Produce a string in double quotes with backslash sequences in all the right places.
    
    参数:
    
    string - A String
    
    返回:
    
    A String correctly formatted for insertion in a JSON message.
  - appendQuoted
```
protected static StringBuilder appendQuoted(String str,
                                            StringBuilder sb)
```
    Appends a string in double quotes with backslash sequences in all the right places.
    
    参数:
    
    string - A String
    
    返回:
    
    the string builder to which the quoted string is appended. It is the same string builder instance that is passed in.
  - getQuotedSize
```
protected static int getQuotedSize(String str)
```
    Returns an estimate of the size of the string in the quoted form. The computation is actually simple; it pads 30% for the escaping.
  - escape
```
public static String escape(String string)
```
  - escape
```
public static String escape(String str,
                            boolean singleQuote)
```
  - appendValue
```
protected static StringBuilder appendValue(Object value,
                                           StringBuilder sb)
```
    Appends the given value to the provided string builder. This is a companion method to valueToString(), but is provided as a performance optimization by avoiding creating intermediate String objects. This form should be used over valueToString() whenever possible.
    
    参数:
    
    value - the value to be appended.
    
    sb - the string builder to which the value should be appended.
    
    返回:
    
    the original string builder instance.
  - getValueSize
```
protected static int getValueSize(Object value)
```
    Returns an estimate of the size of the value in a serialized form. This is provided to size the string builder appropriately.
  - accumulate
```
public JsonObject accumulate(String key,
                             Object value)
                      throws NullPointerException
```
    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.
    
    参数:
    
    key - A key string.
    
    value - An object to be accumulated under the key.
    
    返回:
    
    this.
    
    抛出:
    
    NullPointerException - if the key is null
  - get
```
public Object get(String key)
           throws NoSuchElementException
```
    Get the value object associated with a key.
    
    参数:
    
    key - A key string.
    
    返回:
    
    The object associated with the key.
    
    抛出:
    
    NoSuchElementException - if the key is not found.
  - getBoolean
```
public boolean getBoolean(String key)
                   throws ClassCastException,
                          NoSuchElementException
```
    Get the boolean value associated with a key.
    
    参数:
    
    key - A key string.
    
    返回:
    
    The truth.
    
    抛出:
    
    NoSuchElementException - if the key is not found.
    
    ClassCastException - if the value is not a Boolean or the String "true" or "false".
  - getDouble
```
public double getDouble(String key)
                 throws NoSuchElementException,
                        NumberFormatException
```
    Get the double value associated with a key.
    
    参数:
    
    key - A key string.
    
    返回:
    
    The numeric value.
    
    抛出:
    
    NumberFormatException - if the value cannot be converted to a number.
    
    NoSuchElementException - if the key is not found or if the value is a Number object.
  - getLong
```
public long getLong(String key)
             throws NoSuchElementException,
                    NumberFormatException
```
    Get the long value associated with a key.
    
    参数:
    
    key - A key string.
    
    返回:
    
    The numeric value.
    
    抛出:
    
    NumberFormatException - if the value cannot be converted to a number.
    
    NoSuchElementException - if the key is not found or if the value is a Number object.
  - getInt
```
public int getInt(String key)
           throws NoSuchElementException,
                  NumberFormatException
```
    Get the int value associated with a key.
    
    参数:
    
    key - A key string.
    
    返回:
    
    The integer value.
    
    抛出:
    
    NoSuchElementException - if the key is not found
    
    NumberFormatException - if the value cannot be converted to a number.
  - getJSONArray
```
public JsonArray getJSONArray(String key)
                       throws NoSuchElementException
```
    Get the JSONArray value associated with a key.
    
    参数:
    
    key - A key string.
    
    返回:
    
    A JSONArray which is the value.
    
    抛出:
    
    NoSuchElementException - if the key is not found or if the value is not a JSONArray.
  - getJSONObject
```
public JsonObject getJSONObject(String key)
                         throws NoSuchElementException
```
    Get the JSONObject value associated with a key.
    
    参数:
    
    key - A key string.
    
    返回:
    
    A JSONObject which is the value.
    
    抛出:
    
    NoSuchElementException - if the key is not found or if the value is not a JSONObject.
  - getString
```
public String getString(String key)
                 throws NoSuchElementException
```
    Get the string associated with a key.
    
    参数:
    
    key - A key string.
    
    返回:
    
    A string which is the value.
    
    抛出:
    
    NoSuchElementException - if the key is not found.
  - has
```
public boolean has(String key)
```
    Determine if the JSONObject contains a specific key.
    
    参数:
    
    key - A key string.
    
    返回:
    
    true if the key exists in the JSONObject.
  - isNull
```
public boolean isNull(String key)
```
    Determine if the value associated with the key is null or if there is no value.
    
    参数:
    
    key - A key string.
    
    返回:
    
    true if there is no value associated with the key or if the value is the JSONObject.NULL object.
  - keys
```
public Iterator<String> keys()
```
    Get an enumeration of the keys of the JSONObject.
    
    返回:
    
    An iterator of the keys.
  - length
```
public int length()
```
    Get the number of keys stored in the JSONObject.
    
    返回:
    
    The number of keys in the JSONObject.
  - names
```
public JsonArray names()
```
    Produce a JSONArray containing the names of the elements of this JSONObject.
    
    返回:
    
    A JSONArray containing the key strings, or null if the JSONObject is empty.
  - opt
```
public Object opt(String key)
           throws NullPointerException
```
    Get an optional value associated with a key.
    
    参数:
    
    key - A key string.
    
    返回:
    
    An object which is the value, or null if there is no value.
    
    抛出:
    
    NullPointerException - The key must not be null.
  - optBoolean
```
public boolean optBoolean(String 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 or the String "true".
    
    参数:
    
    key - A key string.
    
    返回:
    
    The truth.
  - optBoolean
```
public boolean optBoolean(String key,
                          boolean defaultValue)
```
    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 or the String "true" or "false" (case insensitive).
    
    参数:
    
    key - A key string.
    
    defaultValue - The default.
    
    返回:
    
    The truth.
  - optDouble
```
public double optDouble(String key)
```
    Get an optional double associated with a key, or NaN if there is no such key or if its value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.
    
    参数:
    
    key - A string which is the key.
    
    返回:
    
    An object which is the value.
  - optDouble
```
public double optDouble(String key,
                        double defaultValue)
```
    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. If the value is a string, an attempt will be made to evaluate it as a number.
    
    参数:
    
    key - A key string.
    
    defaultValue - The default.
    
    返回:
    
    An object which is the value.
  - optInt
```
public int optInt(String key)
```
    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. If the value is a string, an attempt will be made to evaluate it as a number.
    
    参数:
    
    key - A key string.
    
    返回:
    
    An object which is the value.
  - optInt
```
public int optInt(String key,
                  int defaultValue)
```
    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. If the value is a string, an attempt will be made to evaluate it as a number.
    
    参数:
    
    key - A key string.
    
    defaultValue - The default.
    
    返回:
    
    An object which is the value.
  - optJSONArray
```
public JsonArray optJSONArray(String key)
```
    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.
    
    参数:
    
    key - A key string.
    
    返回:
    
    A JSONArray which is the value.
  - optJSONObject
```
public JsonObject optJSONObject(String key)
```
    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.
    
    参数:
    
    key - A key string.
    
    返回:
    
    A JSONObject which is the value.
  - optString
```
public String optString(String key)
```
    Get an optional string associated with a key. It returns an empty string if there is no such key. If the value is not a string and is not null, then it is coverted to a string.
    
    参数:
    
    key - A key string.
    
    返回:
    
    A string which is the value.
  - optString
```
public String optString(String key,
                        String defaultValue)
```
    Get an optional string associated with a key. It returns the defaultValue if there is no such key.
    
    参数:
    
    key - A key string.
    
    defaultValue - The default.
    
    返回:
    
    A string which is the value.
  - put
```
public JsonObject put(String key,
                      boolean value)
```
    Put a key/boolean pair in the JSONObject.
    
    参数:
    
    key - A key string.
    
    value - A boolean which is the value.
    
    返回:
    
    this.
  - put
```
public JsonObject put(String key,
                      double value)
```
    Put a key/double pair in the JSONObject.
    
    参数:
    
    key - A key string.
    
    value - A double which is the value.
    
    返回:
    
    this.
  - put
```
public JsonObject put(String key,
                      int value)
```
    Put a key/int pair in the JSONObject.
    
    参数:
    
    key - A key string.
    
    value - An int which is the value.
    
    返回:
    
    this.
  - put
```
public JsonObject put(String key,
                      Object value)
               throws NullPointerException
```
    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.
    
    参数:
    
    key - A key string.
    
    value - An object which is the value. It should be of one of these types: Boolean, Double, Integer, JSONArray, JSONObject, String, or the JSONObject.NULL object.
    
    返回:
    
    this.
    
    抛出:
    
    NullPointerException - The key must be non-null.
  - putOpt
```
public JsonObject putOpt(String key,
                         Object value)
                  throws NullPointerException
```
    Put a key/value pair in the JSONObject, but only if the value is non-null.
    
    参数:
    
    key - A key string.
    
    value - An object which is the value. It should be of one of these types: Boolean, Double, Integer, JSONArray, JSONObject, String, or the JSONObject.NULL object.
    
    返回:
    
    this.
    
    抛出:
    
    NullPointerException - The key must be non-null.
  - remove
```
public Object remove(String key)
```
    Remove a name and its value, if present.
    
    参数:
    
    key - The name to be removed.
    
    返回:
    
    The value that was associated with the name, or null if there was no value.
  - toJSONArray
```
public JsonArray toJSONArray(JsonArray names)
```
    Produce a JSONArray containing the values of the members of this JSONObject.
    
    参数:
    
    names - A JSONArray containing a list of key strings. This determines the sequence of the values in the result.
    
    返回:
    
    A JSONArray of values.
  - toString
```
public String toString()
```
    Make an JSON external form string of this JSONObject. For compactness, no unnecessary whitespace is added.
    Warning: This method assumes that the data structure is acyclical.
    Warning: whenever toString() is overridden, you must override append() as well. Not overriding append() will result in incorrect serialization results. The append() method should contain the actual concatenation logic and toString() should simply utilize append(). An example of overriding both methods is as follows:
```
 @Override
 public String toString() {
        return append(new StringBuilder()).toString();
 }

 @Override
 public StringBuilder append(StringBuilder sb) {
        sb.append("{value=");
        sb.append(value);
        sb.append('}');
        return sb;
 }
 
```
    覆盖:
    
    toString 在类中 Object
    
    返回:
    
    a printable, displayable, portable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).
  - append
```
public StringBuilder append(StringBuilder sb)
```
    Appends this JsonObject to the provided string builder. This is a companion method to toString(), and is provided as a better way of serializing the object. It avoids creating intermediate String objects in the course of serialization.
    Warning: whenever toString() is overridden, you must override append() as well. Not overriding append() will result in incorrect serialization results. The append() method should contain the actual concatenation logic and toString() should simply utilize append(). An example of overriding both methods is as follows:
```
 @Override
 public String toString() {
        return append(new StringBuilder()).toString();
 }

 @Override
 public StringBuilder append(StringBuilder sb) {
        sb.append("{value=");
        sb.append(value);
        sb.append('}');
        return sb;
 }
 
```
  - toString
```
public String toString(int indentFactor)
```
    Make a prettyprinted JSON external form string of this JSONObject.
    Warning: This method assumes that the data structure is acyclical.
    
    参数:
    
    indentFactor - The number of spaces to add to each level of indentation.
    
    返回:
    
    a printable, displayable, portable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).

类 JsonObject

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

NULL

构造器详细资料

JsonObject

JsonObject

JsonObject

JsonObject

JsonObject

方法详细资料

numberToString

quote

appendQuoted

getQuotedSize

escape

escape

appendValue

getValueSize

accumulate

get

getBoolean

getDouble

getLong

getInt

getJSONArray

getJSONObject

getString

has

isNull

keys

length

names

opt

optBoolean

optBoolean

optDouble

optDouble

optInt

optInt

optJSONArray

optJSONObject

optString

optString

put

put

put

put

putOpt

remove

toJSONArray

toString

append

toString