Package cn.sliew.milky.common.parse.placeholder

Class PropertyPlaceholder

java.lang.Object

cn.sliew.milky.common.parse.placeholder.PropertyPlaceholder

public class PropertyPlaceholder
extends Object

Utility class for working with Strings that have placeholder values in them. A placeholder takes the form ${name}. Using PropertyPlaceholder these placeholders can be substituted for user-supplied values.

Values for substitution can be supplied using a Properties instance or using a PropertyPlaceholder.PlaceholderResolver.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	PropertyPlaceholder.PlaceholderResolver	Strategy interface used to resolve replacement values for placeholders contained in Strings.

Constructor Summary

Constructors

Constructor	Description
PropertyPlaceholder(Logger log, String placeholderPrefix, String placeholderSuffix)	Creates a new PropertyPlaceholderHelper that uses the supplied prefix and suffix.
PropertyPlaceholder(Logger log, String placeholderPrefix, String placeholderSuffix, String valueSeparator, boolean ignoreUnresolvablePlaceholders)	Creates a new PropertyPlaceholderHelper that uses the supplied prefix and suffix.

Method Summary

Modifier and Type	Method	Description
protected String	parseStringValue(String value, PropertyPlaceholder.PlaceholderResolver placeholderResolver, Set<String> visitedPlaceholders)
String	replacePlaceholders(String value, PropertyPlaceholder.PlaceholderResolver placeholderResolver)	Replaces all placeholders of format ${name} with the value returned from the supplied PropertyPlaceholder.PlaceholderResolver.
String	replacePlaceholders(String value, Properties properties)	Replaces all placeholders of format ${name} with the corresponding property from the supplied Properties.

Methods inherited from class java.lang.Object

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

Constructor Detail

PropertyPlaceholder

public PropertyPlaceholder(Logger log,
                           String placeholderPrefix,
                           String placeholderSuffix)

Creates a new PropertyPlaceholderHelper that uses the supplied prefix and suffix. Unresolvable placeholders are ignored.

Parameters:

placeholderPrefix - the prefix that denotes the start of a placeholder

placeholderSuffix - the suffix that denotes the end of a placeholder

PropertyPlaceholder

public PropertyPlaceholder(Logger log,
                           String placeholderPrefix,
                           String placeholderSuffix,
                           String valueSeparator,
                           boolean ignoreUnresolvablePlaceholders)

Creates a new PropertyPlaceholderHelper that uses the supplied prefix and suffix.

Parameters:

placeholderPrefix - the prefix that denotes the start of a placeholder

placeholderSuffix - the suffix that denotes the end of a placeholder

valueSeparator - the separating character between the placeholder variable and the associated default value, if any

ignoreUnresolvablePlaceholders - indicates whether unresolvable placeholders should be ignored (true) or cause an exception (false)

Method Detail

replacePlaceholders

public String replacePlaceholders(String value,
                                  Properties properties)

Replaces all placeholders of format ${name} with the corresponding property from the supplied Properties.

Parameters:

value - the value containing the placeholders to be replaced

properties - the Properties to use for replacement

Returns:

the supplied value with placeholders replaced inline

replacePlaceholders

public String replacePlaceholders(String value,
                                  PropertyPlaceholder.PlaceholderResolver placeholderResolver)

Replaces all placeholders of format ${name} with the value returned from the supplied PropertyPlaceholder.PlaceholderResolver.

Parameters:

value - the value containing the placeholders to be replaced.

placeholderResolver - the PlaceholderResolver to use for replacement.

Returns:

the supplied value with placeholders replaced inline.

Throws:

NullPointerException - if value is null

parseStringValue

protected String parseStringValue(String value,
                                  PropertyPlaceholder.PlaceholderResolver placeholderResolver,
                                  Set<String> visitedPlaceholders)