com.typesafe.config

## Class ConfigResolveOptions

- java.lang.Object
- - com.typesafe.config.ConfigResolveOptions

    public final class ConfigResolveOptions
    extends java.lang.Object

A set of options related to resolving substitutions. Substitutions use the `${foo.bar}` syntax and are documented in the HOCON spec.

Typically this class would be used with the method `Config.resolve(ConfigResolveOptions)`.

This object is immutable, so the "setters" return a new object.

Here is an example of creating a custom `ConfigResolveOptions`:

         ConfigResolveOptions options = ConfigResolveOptions.defaults()
             .setUseSystemEnvironment(false)

In addition to `defaults()`, there's a prebuilt `noSystem()` which avoids looking at any system environment variables or other external system information. (Right now, environment variables are the only example.)

### Method Summary

All Methods Static Methods Instance Methods Concrete Methods
`ConfigResolveOptions` `appendResolver(ConfigResolver value)` Returns options where the given resolver used as a fallback if a reference cannot be otherwise resolved.
`static ConfigResolveOptions` `defaults()` Returns the default resolve options.
`boolean` `getAllowUnresolved()` Returns whether the options allow unresolved substitutions.
`ConfigResolver` `getResolver()` Returns the resolver to use as a fallback if a substitution cannot be otherwise resolved.
`boolean` `getUseSystemEnvironment()` Returns whether the options enable use of system environment variables.
`static ConfigResolveOptions` `noSystem()` Returns resolve options that disable any reference to "system" data (currently, this means environment variables).
`ConfigResolveOptions` `setAllowUnresolved(boolean value)` Returns options with "allow unresolved" set to the given value.
`ConfigResolveOptions` `setUseSystemEnvironment(boolean value)` Returns options with use of environment variables set to the given value.

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

### Method Detail

#### defaults

    public static defaults()

Returns the default resolve options. By default the system environment will be used and unresolved substitutions are not allowed.

Returns:
  the default resolve options

#### noSystem

    public static noSystem()

Returns resolve options that disable any reference to "system" data (currently, this means environment variables).

Returns:
  the resolve options with env variables disabled

#### setUseSystemEnvironment

    public setUseSystemEnvironment(boolean value)

Returns options with use of environment variables set to the given value.

Parameters:
  `value` - true to resolve substitutions falling back to environment variables.
Returns:
  options with requested setting for use of environment variables

#### getUseSystemEnvironment

    public boolean getUseSystemEnvironment()

Returns whether the options enable use of system environment variables. This method is mostly used by the config lib internally, not by applications.

Returns:
  true if environment variables should be used

#### setAllowUnresolved

    public setAllowUnresolved(boolean value)

Returns options with "allow unresolved" set to the given value. By default, unresolved substitutions are an error. If unresolved substitutions are allowed, then a future attempt to use the unresolved value may fail, but `Config.resolve(ConfigResolveOptions)` itself will not throw.

Parameters:
  `value` - true to silently ignore unresolved substitutions.
Returns:
  options with requested setting for whether to allow substitutions
Since:
  1.2.0

#### appendResolver

    public appendResolver(ConfigResolver value)

Returns options where the given resolver used as a fallback if a reference cannot be otherwise resolved. This resolver will only be called after resolution has failed to substitute with a value from within the config itself and with any other resolvers that have been appended before this one. Multiple resolvers can be added using,

         ConfigResolveOptions options = ConfigResolveOptions.defaults()
             .appendResolver(primary)
             .appendResolver(secondary)
             .appendResolver(tertiary);

With this config unresolved references will first be resolved with the primary resolver, if that fails then the secondary, and finally if that also fails the tertiary. If all fallbacks fail to return a substitution "allow unresolved" determines whether resolution fails or continues. `

Parameters:
  `value` - the resolver to fall back to
Returns:
  options that use the given resolver as a fallback
Since:
  1.3.2

#### getResolver

    public getResolver()

Returns the resolver to use as a fallback if a substitution cannot be otherwise resolved. Never returns null. This method is mostly used by the config lib internally, not by applications.

Returns:
  the non-null fallback resolver
Since:
  1.3.2

#### getAllowUnresolved

    public boolean getAllowUnresolved()

Returns whether the options allow unresolved substitutions. This method is mostly used by the config lib internally, not by applications.

Returns:
  true if unresolved substitutions are allowed
Since:
  1.2.0