public interface ConfigObject extends ConfigValue, java.util.Map<java.lang.String,ConfigValue>
ConfigValue representing an object (AKA dictionary or map)
value, as in JSON's curly brace { "a" : 42 } syntax.
An object may also be viewed as a Config by calling
toConfig().
ConfigObject implements java.util.Map<String, ConfigValue> so
you can use it like a regular Java map. Or call unwrapped() to
unwrap the map to a map with plain Java values rather than
ConfigValue.
Like all ConfigValue subtypes, ConfigObject is immutable.
This makes it threadsafe and you never have to create "defensive copies." The
mutator methods from Map all throw
UnsupportedOperationException.
The ConfigValue.valueType() method on an object returns
ConfigValueType.OBJECT.
In most cases you want to use the Config interface rather than this
one. Call toConfig() to convert a ConfigObject to a
Config.
The API for a ConfigObject is in terms of keys, while the API for a
Config is in terms of path expressions. Conceptually,
ConfigObject is a tree of maps from keys to values, while a
Config is a one-level map from paths to values.
Use ConfigUtil.joinPath(java.lang.String...) and ConfigUtil.splitPath(java.lang.String) to convert
between path expressions and individual path elements (keys).
A ConfigObject may contain null values, which will have
ConfigValue.valueType() equal to ConfigValueType.NULL. If
get(Object) returns Java's null then the key was not
present in the parsed file (or wherever this value tree came from). If
get("key") returns a ConfigValue with type
ConfigValueType#NULL then the key was set to null explicitly in the
config file.
Do not implement interface ConfigObject; it should only be
implemented by the config library. Arbitrary implementations will not work
because the library internals assume a specific concrete implementation.
Also, this interface is likely to grow new methods over time, so third-party
implementations will break.
| Modifier and Type | Method and Description |
|---|---|
ConfigValue |
get(java.lang.Object key)
Gets a
ConfigValue at the given key, or returns null if there is
no value. |
Config |
toConfig()
Converts this object to a
Config instance, enabling you to use
path expressions to find values in the object. |
java.util.Map<java.lang.String,java.lang.Object> |
unwrapped()
Recursively unwraps the object, returning a map from String to whatever
plain Java values are unwrapped from the object's values.
|
ConfigObject |
withFallback(ConfigMergeable other)
Returns a new value computed by merging this value with another, with
keys in this value "winning" over the other one.
|
ConfigObject |
withOnlyKey(java.lang.String key)
Clone the object with only the given key (and its children) retained; all
sibling keys are removed.
|
ConfigObject |
withOrigin(ConfigOrigin origin)
Returns a
ConfigValue based on this one, but with the given
origin. |
ConfigObject |
withoutKey(java.lang.String key)
Clone the object with the given key removed.
|
ConfigObject |
withValue(java.lang.String key,
ConfigValue value)
Returns a
ConfigObject based on this one, but with the given key
set to the given value. |
toConfig()
Config instance, enabling you to use
path expressions to find values in the object. This is a constant-time
operation (it is not proportional to the size of the object).Config with this object as its rootjava.util.Map<java.lang.String,java.lang.Object> unwrapped()
unwrapped in interface ConfigValueMap containing plain Java objectswithFallback(ConfigMergeable other)
ConfigMergeableThis associative operation may be used to combine configurations from multiple sources (such as multiple configuration files).
The semantics of merging are described in the spec for HOCON. Merging typically occurs when either the same object is created twice in the same file, or two config files are both loaded. For example:
foo = { a: 42 }
foo = { b: 43 }
Here, the two objects are merged as if you had written:
foo = { a: 42, b: 43 }
Only ConfigObject and Config instances do anything in
this method (they need to merge the fallback keys into themselves). All
other values just return the original value, since they automatically
override any fallback. This means that objects do not merge "across"
non-objects; if you write
object.withFallback(nonObject).withFallback(otherObject),
then otherObject will simply be ignored. This is an
intentional part of how merging works, because non-objects such as
strings and integers replace (rather than merging with) any prior value:
foo = { a: 42 }
foo = 10
Here, the number 10 "wins" and the value of foo would be
simply 10. Again, for details see the spec.withFallback in interface ConfigMergeablewithFallback in interface ConfigValueother - an object whose keys should be used as fallbacks, if the keys
are not present in this oneget(java.lang.Object key)
ConfigValue at the given key, or returns null if there is
no value. The returned ConfigValue may have
ConfigValueType.NULL or any other type, and the passed-in key
must be a key in this object (rather than a path expression).get in interface java.util.Map<java.lang.String,ConfigValue>key - key to look upwithOnlyKey(java.lang.String key)
key - key to keepwithoutKey(java.lang.String key)
key - key to removewithValue(java.lang.String key, ConfigValue value)
ConfigObject based on this one, but with the given key
set to the given value. Does not modify this instance (since it's
immutable). If the key already has a value, that value is replaced. To
remove a value, use withoutKey(String).key - key to addvalue - value at the new keywithOrigin(ConfigOrigin origin)
ConfigValueConfigValue based on this one, but with the given
origin. This is useful when you are parsing a new format of file or setting
comments for a single ConfigValue.withOrigin in interface ConfigValueorigin - the origin set on the returned value