Package uk.ac.ebi.utils.opt.config

Class YAMLLoader

java.lang.Object

uk.ac.ebi.utils.opt.config.YAMLLoader

public class YAMLLoader
extends Object

A simple YAML document/file loader, which is focused on configuration needs. The basic function of this component is loading YAML files and mapping them to POJO classes. It also offers features that are often useful when dealing with application configurations:

• It allows for inclusions, using the INCLUDES_FIELD at the YAML document/file root level (ie, not in a nested level. Optional inclusions are also supported, via INCLUDES_OPTIONAL_FIELD.
• When including a file from a parent, you can extend (instead of override) fields that the parent defined as arrays or objects. Append MERGE_SUFFIX to the field and it's values will be added to the field with the same name (minus the postfix). For instance, if a parent file has: options: [default] and an included file has options @merge: [advanced], the result for options will be [default, advanced]. When mapping to JavaBean properties of type collection, the collection is populated with the merge result (and properties like order or repetitions depend on the exact collection type used for the JavaBean).
• Property interpolation: When using ${propName} in YAML values (not field names), the referred property replaced with values in the JVM properties, or environment variables, or even properties defined via PROPDEF_FIELD. This is based on Spring

See the unit tests for examples of use.

TODO: support for URLs
TODO: Support Spring SpEL for interpolation.
TODO: support for charsets?

Author:

brandizi

Date:

14 Jun 2022

Field Summary

Fields

Modifier and Type	Field	Description
static final String	INCLUDES_FIELD
static final String	INCLUDES_OPTIONAL_FIELD
static final String	MERGE_SUFFIX
static final String	MY_DIR_PROP	A property with this name is always available and contains the dir in which the YAML file is
static final String	MY_PATH_PROP	A property with this name is always available and contains the absolute YAML file path
static final String	PROPDEF_FIELD

Constructor Summary

Constructors

Constructor	Description
YAMLLoader()

Method Summary

Modifier and Type	Method	Description
static <T> T	loadYAMLFromFile(String filePath, Class<T> targetClass)
static <T> T	loadYAMLFromString(String yamlStr, Class<T> targetClass)	Maps a YAML file to a target, after it has been processes as explained above.

Methods inherited from class java.lang.Object

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

Field Details

INCLUDES_FIELD

public static final String INCLUDES_FIELD

See Also:

• Constant Field Values

INCLUDES_OPTIONAL_FIELD

public static final String INCLUDES_OPTIONAL_FIELD

See Also:

• Constant Field Values

MERGE_SUFFIX

public static final String MERGE_SUFFIX

See Also:

• Constant Field Values

PROPDEF_FIELD

public static final String PROPDEF_FIELD

See Also:

• Constant Field Values

MY_PATH_PROP

public static final String MY_PATH_PROP

A property with this name is always available and contains the absolute YAML file path

See Also:

• Constant Field Values

MY_DIR_PROP

public static final String MY_DIR_PROP

A property with this name is always available and contains the dir in which the YAML file is

See Also:

• Constant Field Values

Constructor Details

YAMLLoader

public YAMLLoader()

Method Details

loadYAMLFromFile

public static <T> T loadYAMLFromFile(String filePath,
 Class<T> targetClass)
                              throws UncheckedIOException

Throws:

UncheckedIOException

loadYAMLFromString

public static <T> T loadYAMLFromString(String yamlStr,
 Class<T> targetClass)

Maps a YAML file to a target, after it has been processes as explained above.