Package io.joshworks.snappy.loader.util

Class SystemPropertyUtils

java.lang.Object

io.joshworks.snappy.loader.util.SystemPropertyUtils

public abstract class SystemPropertyUtils
extends Object

Helper class for resolving placeholders in texts. Usually applied to file paths.

A text may contain $ ... placeholders, to be resolved as system properties: e.g. $ user.dir . Default values can be supplied using the ":" separator between key and value.

Adapted from Spring.

Author:

Juergen Hoeller, Rob Harrop, Dave Syer

See Also:

System.getProperty(String)

Field Summary

Fields

Modifier and Type	Field	Description
static String	PLACEHOLDER_PREFIX	Prefix for system property placeholders: "${".
static String	PLACEHOLDER_SUFFIX	Suffix for system property placeholders: "}".
static String	VALUE_SEPARATOR	Value separator for system property placeholders: ":".

Constructor Summary

Constructors

Constructor	Description
SystemPropertyUtils()

Method Summary

Modifier and Type	Method	Description
static String	getProperty(String key)
static String	getProperty(String key, String defaultValue)
static String	getProperty(String key, String defaultValue, String text)	Search the System properties and environment variables for a value with the provided key.
static String	resolvePlaceholders(String text)	Resolve ${...} placeholders in the given text, replacing them with corresponding system property values.
static String	resolvePlaceholders(Properties properties, String text)	Resolve ${...} placeholders in the given text, replacing them with corresponding system property values.

Methods inherited from class java.lang.Object

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

Field Detail

PLACEHOLDER_PREFIX

public static final String PLACEHOLDER_PREFIX

Prefix for system property placeholders: "${".

See Also:

Constant Field Values

PLACEHOLDER_SUFFIX

public static final String PLACEHOLDER_SUFFIX

Suffix for system property placeholders: "}".

See Also:

Constant Field Values

VALUE_SEPARATOR

public static final String VALUE_SEPARATOR

Value separator for system property placeholders: ":".

See Also:

Constant Field Values

Constructor Detail

SystemPropertyUtils

public SystemPropertyUtils()

Method Detail

resolvePlaceholders

public static String resolvePlaceholders(String text)

Resolve ${...} placeholders in the given text, replacing them with corresponding system property values.

Parameters:

text - the String to resolve

Returns:

the resolved String

Throws:

IllegalArgumentException - if there is an unresolvable placeholder

See Also:

PLACEHOLDER_PREFIX, PLACEHOLDER_SUFFIX

resolvePlaceholders

public static String resolvePlaceholders(Properties properties,
                                         String text)

Resolve ${...} placeholders in the given text, replacing them with corresponding system property values.

Parameters:

properties - a properties instance to use in addition to System

text - the String to resolve

Returns:

the resolved String

Throws:

IllegalArgumentException - if there is an unresolvable placeholder

See Also:

PLACEHOLDER_PREFIX, PLACEHOLDER_SUFFIX

getProperty

public static String getProperty(String key)

getProperty

public static String getProperty(String key,
                                 String defaultValue)

getProperty

public static String getProperty(String key,
                                 String defaultValue,
                                 String text)

Search the System properties and environment variables for a value with the provided key. Environment variables in UPPER_CASE style are allowed where System properties would normally be lower.case.

Parameters:

key - the key to resolve

defaultValue - the default value

text - optional extra context for an error message if the key resolution fails (e.g. if System properties are not accessible)

Returns:

a static property value or null of not found