Package com.typesafe.config

Class ConfigFactory

  • public final class ConfigFactory
extends java.lang.Object
    Contains static methods for creating Config instances.

    See also ConfigValueFactory which contains static methods for converting Java values into a ConfigObject. You can then convert a ConfigObject into a Config with ConfigObject.toConfig().

    The static methods with "load" in the name do some sort of higher-level operation potentially parsing multiple resources and resolving substitutions, while the ones with "parse" in the name just create a ConfigValue from a resource and nothing else.

    You can find an example app and library on GitHub. Also be sure to read the package overview which describes the big picture as shown in those examples.

    • Method Detail

      • load

        public static load​(java.lang.String resourceBasename)
        Loads an application's configuration from the given classpath resource or classpath resource basename, sandwiches it between default reference config and default overrides, and then resolves it. The classpath resource is "raw" (it should have no "/" prefix, and is not made relative to any package, so it's like ClassLoader.getResource(java.lang.String) not Class.getResource(java.lang.String)).

        Resources are loaded from the current thread's Thread.getContextClassLoader(). In general, a library needs its configuration to come from the class loader used to load that library, so the proper "reference.conf" are present.

        The loaded object will already be resolved (substitutions have already been processed). As a result, if you add more fallbacks then they won't be seen by substitutions. Substitutions are the "${foo.bar}" syntax. If you want to parse additional files or something then you need to use load(Config).

        To load a standalone resource (without the default reference and default overrides), use parseResourcesAnySyntax(String) rather than this method. To load only the reference config use defaultReference() and to load only the overrides use defaultOverrides().

        Parameters:
        resourceBasename - name (optionally without extension) of a resource on classpath
        Returns:
        configuration for an application relative to context class loader

      • load

        public static load​(java.lang.ClassLoader loader,
                          java.lang.String resourceBasename)
        Like load(String) but uses the supplied class loader instead of the current thread's context class loader.

        To load a standalone resource (without the default reference and default overrides), use parseResourcesAnySyntax(ClassLoader, String) rather than this method. To load only the reference config use defaultReference(ClassLoader) and to load only the overrides use defaultOverrides(ClassLoader).

        Parameters:
        loader - class loader to look for resources in
        resourceBasename - basename (no .conf/.json/.properties suffix)
        Returns:
        configuration for an application relative to given class loader

      • load

        public static load​(java.lang.String resourceBasename,
                          ConfigParseOptions parseOptions,
                          ConfigResolveOptions resolveOptions)
        Like load(String) but allows you to specify parse and resolve options.
        Parameters:
        resourceBasename - the classpath resource name with optional extension
        parseOptions - options to use when parsing the resource
        resolveOptions - options to use when resolving the stack
        Returns:
        configuration for an application

      • load

        public static load​(java.lang.ClassLoader loader,
                          java.lang.String resourceBasename,
                          ConfigParseOptions parseOptions,
                          ConfigResolveOptions resolveOptions)
        Like load(String,ConfigParseOptions,ConfigResolveOptions) but has a class loader parameter that overrides any from the ConfigParseOptions.
        Parameters:
        loader - class loader in which to find resources (overrides loader in parse options)
        resourceBasename - the classpath resource name with optional extension
        parseOptions - options to use when parsing the resource (class loader overridden)
        resolveOptions - options to use when resolving the stack
        Returns:
        configuration for an application

      • load

        public static load​(Config config)
        Assembles a standard configuration using a custom Config object rather than loading "application.conf". The Config object will be sandwiched between the default reference config and default overrides and then resolved.
        Parameters:
        config - the application's portion of the configuration
        Returns:
        resolved configuration with overrides and fallbacks added

      • load

        public static load​(java.lang.ClassLoader loader,
                          Config config)
        Like load(Config) but allows you to specify the class loader for looking up resources.
        Parameters:
        loader - the class loader to use to find resources
        config - the application's portion of the configuration
        Returns:
        resolved configuration with overrides and fallbacks added

      • load

        public static load​(Config config,
                          ConfigResolveOptions resolveOptions)
        Like load(Config) but allows you to specify ConfigResolveOptions.
        Parameters:
        config - the application's portion of the configuration
        resolveOptions - options for resolving the assembled config stack
        Returns:
        resolved configuration with overrides and fallbacks added

      • load

        public static load​(java.lang.ClassLoader loader,
                          Config config,
                          ConfigResolveOptions resolveOptions)
        Like load(Config,ConfigResolveOptions) but allows you to specify a class loader other than the context class loader.
        Parameters:
        loader - class loader to use when looking up override and reference configs
        config - the application's portion of the configuration
        resolveOptions - options for resolving the assembled config stack
        Returns:
        resolved configuration with overrides and fallbacks added

      • load

        public static load()
        Loads a default configuration, equivalent to load(defaultApplication()) in most cases. This configuration should be used by libraries and frameworks unless an application provides a different one.

        This method may return a cached singleton so will not see changes to system properties or config files. (Use invalidateCaches() to force it to reload.)

        Returns:
        configuration for an application

      • load

        public static load​(ConfigParseOptions parseOptions)
        Like load() but allows specifying parse options.
        Parameters:
        parseOptions - Options for parsing resources
        Returns:
        configuration for an application

      • load

        public static load​(java.lang.ClassLoader loader)
        Like load() but allows specifying a class loader other than the thread's current context class loader.
        Parameters:
        loader - class loader for finding resources
        Returns:
        configuration for an application

      • load

        public static load​(java.lang.ClassLoader loader,
                          ConfigParseOptions parseOptions)
        Like load() but allows specifying a class loader other than the thread's current context class loader and also specify parse options.
        Parameters:
        loader - class loader for finding resources (overrides any loader in parseOptions)
        parseOptions - Options for parsing resources
        Returns:
        configuration for an application

      • load

        public static load​(java.lang.ClassLoader loader,
                          ConfigResolveOptions resolveOptions)
        Like load() but allows specifying a class loader other than the thread's current context class loader and also specify resolve options.
        Parameters:
        loader - class loader for finding resources
        resolveOptions - options for resolving the assembled config stack
        Returns:
        configuration for an application

      • load

        public static load​(java.lang.ClassLoader loader,
                          ConfigParseOptions parseOptions,
                          ConfigResolveOptions resolveOptions)
        Like load() but allows specifying a class loader other than the thread's current context class loader, parse options, and resolve options.
        Parameters:
        loader - class loader for finding resources (overrides any loader in parseOptions)
        parseOptions - Options for parsing resources
        resolveOptions - options for resolving the assembled config stack
        Returns:
        configuration for an application

      • load

        public static load​(ConfigParseOptions parseOptions,
                          ConfigResolveOptions resolveOptions)
        Like load() but allows specifying parse options and resolve options.
        Parameters:
        parseOptions - Options for parsing resources
        resolveOptions - options for resolving the assembled config stack
        Returns:
        configuration for an application
        Since:
        1.3.0

      • defaultReference

        public static defaultReference()
        Obtains the default reference configuration, which is currently created by merging all resources "reference.conf" found on the classpath and overriding the result with system properties. The returned reference configuration will already have substitutions resolved.

        Libraries and frameworks should ship with a "reference.conf" in their jar.

        The reference config must be looked up in the class loader that contains the libraries that you want to use with this config, so the "reference.conf" for each library can be found. Use defaultReference(ClassLoader) if the context class loader is not suitable.

        The load() methods merge this configuration for you automatically.

        Future versions may look for reference configuration in more places. It is not guaranteed that this method only looks at "reference.conf".

        Returns:
        the default reference config for context class loader

      • defaultReference

        public static defaultReference​(java.lang.ClassLoader loader)
        Like defaultReference() but allows you to specify a class loader to use rather than the current context class loader.
        Parameters:
        loader - class loader to look for resources in
        Returns:
        the default reference config for this class loader

      • defaultReferenceUnresolved

        public static defaultReferenceUnresolved()
        Obtains the default reference configuration, which is currently created by merging all resources "reference.conf" found on the classpath and overriding the result with system properties.

        While the returned reference configuration is guaranteed to be resolvable (that is, there will be no substitutions that cannot be resolved), it is returned in an unresolved state for the purpose of allowing substitutions to be overridden by a config layer that falls back to this one.

        Libraries and frameworks should ship with a "reference.conf" in their jar.

        The reference config must be looked up in the class loader that contains the libraries that you want to use with this config, so the "reference.conf" for each library can be found. Use defaultReference(ClassLoader) if the context class loader is not suitable.

        The load() methods merge this configuration for you automatically.

        Future versions may look for reference configuration in more places. It is not guaranteed that this method only looks at "reference.conf".

        Returns:
        the unresolved default reference config for the context class loader

      • defaultReferenceUnresolved

        public static defaultReferenceUnresolved​(java.lang.ClassLoader loader)
        Like defaultReferenceUnresolved() but allows you to specify a class loader to use rather than the current context class loader.
        Parameters:
        loader - class loader to look for resources in
        Returns:
        the unresolved default reference config for this class loader

      • defaultOverrides

        public static defaultOverrides()
        Obtains the default override configuration, which currently consists of system properties. The returned override configuration will already have substitutions resolved.

        The load() methods merge this configuration for you automatically.

        Future versions may get overrides in more places. It is not guaranteed that this method only uses system properties.

        Returns:
        the default override configuration

      • defaultOverrides

        public static defaultOverrides​(java.lang.ClassLoader loader)
        Like defaultOverrides() but allows you to specify a class loader to use rather than the current context class loader.
        Parameters:
        loader - class loader to look for resources in
        Returns:
        the default override configuration

      • defaultApplication

        public static defaultApplication()
        Obtains the default application-specific configuration, which defaults to parsing application.conf, application.json, and application.properties on the classpath, but can also be rerouted using the config.file, config.resource, and config.url system properties.

        The no-arguments load() method automatically stacks the defaultReference(), defaultApplication(), and defaultOverrides() configs. You would use defaultApplication() directly only if you're somehow customizing behavior by reimplementing load().

        The configuration returned by defaultApplication() will not be resolved already, in contrast to defaultReference() and defaultOverrides(). This is because application.conf would normally be resolved after merging with the reference and override configs.

        If the system properties config.resource, config.file, or config.url are set, then the classpath resource, file, or URL specified in those properties will be used rather than the default application.{conf,json,properties} classpath resources. These system properties should not be set in code (after all, you can just parse whatever you want manually and then use load(Config) if you don't want to use application.conf). The properties are intended for use by the person or script launching the application. For example someone might have a production.conf that include application.conf but then change a couple of values. When launching the app they could specify -Dconfig.resource=production.conf to get production mode.

        If no system properties are set to change the location of the default configuration, defaultApplication() is equivalent to ConfigFactory.parseResources("application").

        Returns:
        the default application.conf or system-property-configured configuration
        Since:
        1.3.0

      • defaultApplication

        public static defaultApplication​(java.lang.ClassLoader loader)
        Like defaultApplication() but allows you to specify a class loader to use rather than the current context class loader.
        Parameters:
        loader - class loader to look for resources in
        Returns:
        the default application configuration
        Since:
        1.3.0

      • invalidateCaches

        public static void invalidateCaches()
        Reloads any cached configs, picking up changes to system properties for example. Because a Config is immutable, anyone with a reference to the old configs will still have the same outdated objects. However, new calls to load() or defaultOverrides() or defaultReference() may return a new object.

        This method is primarily intended for use in unit tests, for example, that may want to update a system property then confirm that it's used correctly. In many cases, use of this method may indicate there's a better way to set up your code.

        Caches may be reloaded immediately or lazily; once you call this method, the reload can occur at any time, even during the invalidation process. So FIRST make the changes you'd like the caches to notice, then SECOND call this method to invalidate caches. Don't expect that invalidating, making changes, then calling load(), will work. Make changes before you invalidate.

      • empty

        public static empty()
        Gets an empty configuration. See also empty(String) to create an empty configuration with a description, which may improve user-visible error messages.
        Returns:
        an empty configuration

      • empty

        public static empty​(java.lang.String originDescription)
        Gets an empty configuration with a description to be used to create a ConfigOrigin for this Config. The description should be very short and say what the configuration is, like "default settings" or "foo settings" or something. (Presumably you will merge some actual settings into this empty config using Config.withFallback(com.typesafe.config.ConfigMergeable), making the description more useful.)
        Parameters:
        originDescription - description of the config
        Returns:
        an empty configuration

      • systemEnvironmentOverrides

        public static systemEnvironmentOverrides()
        Gets a Config containing the system's environment variables used to override configuration keys. Environment variables taken in considerations are starting with CONFIG_FORCE_

        Environment variables are mangled in the following way after stripping the prefix "CONFIG_FORCE_":

        environment variables
        Env Var Config
        _   [1 underscore] . [dot]
        __  [2 underscore] - [dash]
        ___ [3 underscore] _ [underscore]

        A variable like: CONFIG_FORCE_a_b__c___d is translated to a config key: a.b-c_d

        This method can return a global immutable singleton, so it's preferred over parsing system properties yourself.

        defaultOverrides() will include the system environment variables as overrides if `config.override_with_env_vars` is set to `true`.

        Returns:
        system environment variable overrides parsed into a Config

      • systemEnvironment

        public static systemEnvironment()
        Gets a Config containing the system's environment variables. This method can return a global immutable singleton.

        Environment variables are used as fallbacks when resolving substitutions whether or not this object is included in the config being resolved, so you probably don't need to use this method for most purposes. It can be a nicer API for accessing environment variables than raw System.getenv(String) though, since you can use methods such as Config.getInt(java.lang.String).

        Returns:
        system environment variables parsed into a Config

      • parseProperties

        public static parseProperties​(java.util.Properties properties,
                                     ConfigParseOptions options)
        Converts a Java Properties object to a ConfigObject using the rules documented in the HOCON spec. The keys in the Properties object are split on the period character '.' and treated as paths. The values will all end up as string values. If you have both "a=foo" and "a.b=bar" in your properties file, so "a" is both the object containing "b" and the string "foo", then the string value is dropped.

        If you want to have System.getProperties() as a ConfigObject, it's better to use the systemProperties() method which returns a cached global singleton.

        Parameters:
        properties - a Java Properties object
        options - the parse options
        Returns:
        the parsed configuration

      • parseReader

        public static parseReader​(java.io.Reader reader,
                                 ConfigParseOptions options)
        Parses a Reader into a Config instance. Does not call Config.resolve() or merge the parsed stream with any other configuration; this method parses a single stream and does nothing else. It does process "include" statements in the parsed stream, and may end up doing other IO due to those statements.
        Parameters:
        reader - the reader to parse
        options - parse options to control how the reader is interpreted
        Returns:
        the parsed configuration
        Throws:
        ConfigException - on IO or parse errors

      • parseURL

        public static parseURL​(java.net.URL url,
                              ConfigParseOptions options)
        Parses a URL into a Config instance. Does not call Config.resolve() or merge the parsed stream with any other configuration; this method parses a single stream and does nothing else. It does process "include" statements in the parsed stream, and may end up doing other IO due to those statements.
        Parameters:
        url - the url to parse
        options - parse options to control how the url is interpreted
        Returns:
        the parsed configuration
        Throws:
        ConfigException - on IO or parse errors

      • parseURL

        public static parseURL​(java.net.URL url)
        Parses a url into a Config instance as with parseURL(URL,ConfigParseOptions) but always uses the default parse options.
        Parameters:
        url - the url to parse
        Returns:
        the parsed configuration
        Throws:
        ConfigException - on IO or parse errors

      • parseFile

        public static parseFile​(java.io.File file,
                               ConfigParseOptions options)
        Parses a file into a Config instance. Does not call Config.resolve() or merge the file with any other configuration; this method parses a single file and does nothing else. It does process "include" statements in the parsed file, and may end up doing other IO due to those statements.
        Parameters:
        file - the file to parse
        options - parse options to control how the file is interpreted
        Returns:
        the parsed configuration
        Throws:
        ConfigException - on IO or parse errors

      • parseFile

        public static parseFile​(java.io.File file)
        Parses a file into a Config instance as with parseFile(File,ConfigParseOptions) but always uses the default parse options.
        Parameters:
        file - the file to parse
        Returns:
        the parsed configuration
        Throws:
        ConfigException - on IO or parse errors

      • parseFileAnySyntax

        public static parseFileAnySyntax​(java.io.File fileBasename,
                                        ConfigParseOptions options)
        Parses a file with a flexible extension. If the fileBasename already ends in a known extension, this method parses it according to that extension (the file's syntax must match its extension). If the fileBasename does not end in an extension, it parses files with all known extensions and merges whatever is found.

        In the current implementation, the extension ".conf" forces ConfigSyntax.CONF, ".json" forces ConfigSyntax.JSON, and ".properties" forces ConfigSyntax.PROPERTIES. When merging files, ".conf" falls back to ".json" falls back to ".properties".

        Future versions of the implementation may add additional syntaxes or additional extensions. However, the ordering (fallback priority) of the three current extensions will remain the same.

        If options forces a specific syntax, this method only parses files with an extension matching that syntax.

        If options.getAllowMissing() is true, then no files have to exist; if false, then at least one file has to exist.

        Parameters:
        fileBasename - a filename with or without extension
        options - parse options
        Returns:
        the parsed configuration

      • parseResources

        public static parseResources​(java.lang.Class<?> klass,
                                    java.lang.String resource,
                                    ConfigParseOptions options)
        Parses all resources on the classpath with the given name and merges them into a single Config.

        If the resource name does not begin with a "/", it will have the supplied class's package added to it, in the same way as Class.getResource(java.lang.String).

        Duplicate resources with the same name are merged such that ones returned earlier from ClassLoader.getResources(java.lang.String) fall back to (have higher priority than) the ones returned later. This implies that resources earlier in the classpath override those later in the classpath when they configure the same setting. However, in practice real applications may not be consistent about classpath ordering, so be careful. It may be best to avoid assuming too much.

        Parameters:
        klass - klass.getClassLoader() will be used to load resources, and non-absolute resource names will have this class's package added
        resource - resource to look up, relative to klass's package or absolute starting with a "/"
        options - parse options
        Returns:
        the parsed configuration

      • parseResources

        public static parseResources​(java.lang.Class<?> klass,
                                    java.lang.String resource)
        Like parseResources(Class,String,ConfigParseOptions) but always uses default parse options.
        Parameters:
        klass - klass.getClassLoader() will be used to load resources, and non-absolute resource names will have this class's package added
        resource - resource to look up, relative to klass's package or absolute starting with a "/"
        Returns:
        the parsed configuration

      • parseResourcesAnySyntax

        public static parseResourcesAnySyntax​(java.lang.Class<?> klass,
                                             java.lang.String resourceBasename,
                                             ConfigParseOptions options)
        Parses classpath resources with a flexible extension. In general, this method has the same behavior as parseFileAnySyntax(File,ConfigParseOptions) but for classpath resources instead, as in parseResources(java.lang.Class<?>, java.lang.String, com.typesafe.config.ConfigParseOptions).

        There is a thorny problem with this method, which is that ClassLoader.getResources(java.lang.String) must be called separately for each possible extension. The implementation ends up with separate lists of resources called "basename.conf" and "basename.json" for example. As a result, the ideal ordering between two files with different extensions is unknown; there is no way to figure out how to merge the two lists in classpath order. To keep it simple, the lists are simply concatenated, with the same syntax priorities as parseFileAnySyntax() - all ".conf" resources are ahead of all ".json" resources which are ahead of all ".properties" resources.

        Parameters:
        klass - class which determines the ClassLoader and the package for relative resource names
        resourceBasename - a resource name as in Class.getResource(java.lang.String), with or without extension
        options - parse options (class loader is ignored in favor of the one from klass)
        Returns:
        the parsed configuration

      • parseResourcesAnySyntax

        public static parseResourcesAnySyntax​(java.lang.Class<?> klass,
                                             java.lang.String resourceBasename)
        Like parseResourcesAnySyntax(Class,String,ConfigParseOptions) but always uses default parse options.
        Parameters:
        klass - klass.getClassLoader() will be used to load resources, and non-absolute resource names will have this class's package added
        resourceBasename - a resource name as in Class.getResource(java.lang.String), with or without extension
        Returns:
        the parsed configuration

      • parseResources

        public static parseResources​(java.lang.ClassLoader loader,
                                    java.lang.String resource,
                                    ConfigParseOptions options)
        Parses all resources on the classpath with the given name and merges them into a single Config.

        This works like ClassLoader.getResource(java.lang.String), not like Class.getResource(java.lang.String), so the name never begins with a slash.

        See parseResources(Class,String,ConfigParseOptions) for full details.

        Parameters:
        loader - will be used to load resources by setting this loader on the provided options
        resource - resource to look up
        options - parse options (class loader is ignored)
        Returns:
        the parsed configuration

      • parseResources

        public static parseResources​(java.lang.ClassLoader loader,
                                    java.lang.String resource)
        Like parseResources(ClassLoader,String,ConfigParseOptions) but always uses default parse options.
        Parameters:
        loader - will be used to load resources
        resource - resource to look up in the loader
        Returns:
        the parsed configuration

      • parseResourcesAnySyntax

        public static parseResourcesAnySyntax​(java.lang.ClassLoader loader,
                                             java.lang.String resourceBasename)
        Like parseResourcesAnySyntax(ClassLoader,String,ConfigParseOptions) but always uses default parse options.
        Parameters:
        loader - will be used to load resources
        resourceBasename - a resource name as in ClassLoader.getResource(java.lang.String), with or without extension
        Returns:
        the parsed configuration

      • parseResources

        public static parseResources​(java.lang.String resource)
        Like parseResources(ClassLoader,String) but uses thread's current context class loader.
        Parameters:
        resource - the resource name
        Returns:
        the parsed configuration

      • parseApplicationReplacement

        public static java.util.Optional<parseApplicationReplacement()
        Parse only any application replacement (specified by one of config.{resource,file,url}), returning an empty Config if no overrides were set.
        Returns:
        a Optional containing any specified replacement, or Optional.empty() if none was specified.
        Since:
        1.4.1

      • parseApplicationReplacement

        public static java.util.Optional<parseApplicationReplacement​(java.lang.ClassLoader loader)
        Like parseApplicationReplacement() but allows you to specify a class loader ti yse rather than the current context class loader.
        Parameters:
        loader - the class loader
        Returns:
        a Optional containing any specified replacement, or Optional.empty() if none was specified.
        Since:
        1.4.1

      • parseString

        public static parseString​(java.lang.String s,
                                 ConfigParseOptions options)
        Parses a string (which should be valid HOCON or JSON by default, or the syntax specified in the options otherwise).
        Parameters:
        s - string to parse
        options - parse options
        Returns:
        the parsed configuration

      • parseString

        public static parseString​(java.lang.String s)
        Parses a string (which should be valid HOCON or JSON).
        Parameters:
        s - string to parse
        Returns:
        the parsed configuration

      • parseMap

        public static parseMap​(java.util.Map<java.lang.String,​? extends java.lang.Object> values,
                              java.lang.String originDescription)
        Creates a Config based on a Map from paths to plain Java values. Similar to ConfigValueFactory.fromMap(Map,String), except the keys in the map are path expressions, rather than keys; and correspondingly it returns a Config instead of a ConfigObject. This is more convenient if you are writing literal maps in code, and less convenient if you are getting your maps from some data source such as a parser.

        An exception will be thrown (and it is a bug in the caller of the method) if a path is both an object and a value, for example if you had both "a=foo" and "a.b=bar", then "a" is both the string "foo" and the parent object of "b". The caller of this method should ensure that doesn't happen.

        Parameters:
        values - map from paths to plain Java objects
        originDescription - description of what this map represents, like a filename, or "default settings" (origin description is used in error messages)
        Returns:
        the map converted to a Config

      • parseMap

        public static parseMap​(java.util.Map<java.lang.String,​? extends java.lang.Object> values)
        See the other overload of parseMap(Map, String) for details, this one just uses a default origin description.
        Parameters:
        values - map from paths to plain Java values
        Returns:
        the map converted to a Config