Package org.jmxtrans.embedded.util.json

Class PropertyPlaceholderResolver

java.lang.Object

org.jmxtrans.embedded.util.json.PropertyPlaceholderResolver

All Implemented Interfaces:

Serializable

public class PropertyPlaceholderResolver
extends Object
implements Serializable

Inspired by Spring Property placeholder mechanism. Placeholders are delimited by '{' and '}' and support default value with ':'. Sample : '{graphite.host}' or '{graphite.port:2003}'. If the placeholder is not found in the system properties, it is searched in the environment variables and then converted to underscore delimited upper case and searched in environment variables. Sample for '{graphite.port:2003}':

1. System.getProperty("graphite.port")
2. System.getenv("graphite.port")
3. System.getenv("GRAPHITE_PORT")
4. default to 2003

Author:

Cyrille Le Clerc

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
PropertyPlaceholderResolver()

Method Summary

Modifier and Type	Method	Description
protected String	resolvePlaceholder(String property, String defaultValue)	Search for the given placeholder in system properties then in environment variables.
String	resolveString(String string)	Parse the given string resolving property placeholders (${my-property[:default-value]})

Methods inherited from class java.lang.Object

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

Constructor Details

PropertyPlaceholderResolver

public PropertyPlaceholderResolver()

Method Details

resolveString

@Nonnull
public String resolveString(@Nonnull
String string)
                     throws EmbeddedJmxTransException

Parse the given string resolving property placeholders (${my-property[:default-value]})

Parameters:

string - the string to parse.

Returns:

the parsed string.

Throws:

EmbeddedJmxTransException - a property placeholder could not be resolved and no default value has been defined.

resolvePlaceholder

@Nonnull
protected String resolvePlaceholder(String property,
@Nullable
String defaultValue)
                             throws EmbeddedJmxTransException

Search for the given placeholder in system properties then in environment variables.

Parameters:

property - property to resolve

defaultValue - Default value if the placeholder is not found. null means not default value is defined and the placeholder must exist

Returns:

the resolved property or the default value if the placeholder is not found and the default value is defined

Throws:

EmbeddedJmxTransException - if the placeholder is not found and the given defaultValue is not defined (null)