org.syphr.prom.PropertiesManagers Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of prom Show documentation
Show all versions of prom Show documentation
Prom provides easy access to and lifecycle management for properties files in Java.
/*
* Copyright 2010 Gregory P. Moyer
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.syphr.prom;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Properties;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* This class provides builder methods to construct {@link PropertiesManager
* managers} with various options.
*
* @author Gregory P. Moyer
*/
public class PropertiesManagers
{
/**
* Build a new manager for the given properties file.
*
* @param
* the type of key used for the new manager
*
* @param file
* the file system location of the properties represented by the
* new manager
* @param defaultFile
* a file containing default values for the properties
* represented by the new manager
* @param keyType
* the enumeration of keys in the properties file
* @return a new manager
* @throws IOException
* if there is an error while reading the default properties
*/
public static > PropertiesManager newManager(File file,
File defaultFile,
Class keyType) throws IOException
{
return new PropertiesManager(file,
getProperties(defaultFile),
getEnumTranslator(keyType),
new DefaultEvaluator(),
Executors.newCachedThreadPool());
}
/**
* Build a new manager for the given properties file.
*
* @param
* the type of key used for the new manager
*
* @param file
* the file system location of the properties represented by the
* new manager
* @param defaultFile
* a URL containing default values for the properties
* represented by the new manager
* @param keyType
* the enumeration of keys in the properties file
* @return a new manager
* @throws IOException
* if there is an error while reading the default properties
*/
public static > PropertiesManager newManager(File file,
URL defaultFile,
Class keyType) throws IOException
{
return new PropertiesManager(file,
getProperties(defaultFile),
getEnumTranslator(keyType),
new DefaultEvaluator(),
Executors.newCachedThreadPool());
}
/**
* Build a new manager for the given properties file.
*
* @param
* the type of key used for the new manager
*
* @param file
* the file system location of the properties represented by the
* new manager
* @param defaultFile
* a file containing default values for the properties
* represented by the new manager
* @param keyType
* the enumeration of keys in the properties file
* @param executor
* a service to handle potentially long running tasks, such as
* interacting with the file system
* @return a new manager
* @throws IOException
* if there is an error while reading the default properties
*/
public static > PropertiesManager newManager(File file,
File defaultFile,
Class keyType,
ExecutorService executor) throws IOException
{
return new PropertiesManager(file,
getProperties(defaultFile),
getEnumTranslator(keyType),
new DefaultEvaluator(),
executor);
}
/**
* Build a new manager for the given properties file.
*
* @param
* the type of key used for the new manager
*
* @param file
* the file system location of the properties represented by the
* new manager
* @param defaultFile
* a URL containing default values for the properties
* represented by the new manager
* @param keyType
* the enumeration of keys in the properties file
* @param executor
* a service to handle potentially long running tasks, such as
* interacting with the file system
* @return a new manager
* @throws IOException
* if there is an error while reading the default properties
*/
public static > PropertiesManager newManager(File file,
URL defaultFile,
Class keyType,
ExecutorService executor) throws IOException
{
return new PropertiesManager(file,
getProperties(defaultFile),
getEnumTranslator(keyType),
new DefaultEvaluator(),
executor);
}
/**
* Build a new manager for the given properties file.
*
* @param
* the type of key used for the new manager
*
* @param file
* the file system location of the properties represented here
* @param keyType
* the enumeration of keys in the properties file
* @return a new manager
*/
public static & Defaultable> PropertiesManager newManager(File file,
Class keyType)
{
Translator translator = getEnumTranslator(keyType);
return new PropertiesManager(file,
getDefaultProperties(keyType,
translator),
translator,
new DefaultEvaluator(),
Executors.newCachedThreadPool());
}
/**
* Build a new manager for the given properties file.
*
* @param
* the type of key used for the new manager
*
* @param file
* the file system location of the properties represented here
* @param keyType
* the enumeration of keys in the properties file
* @param executor
* a service to handle potentially long running tasks, such as
* interacting with the file system
* @return a new manager
*/
public static & Defaultable> PropertiesManager newManager(File file,
Class keyType,
ExecutorService executor)
{
Translator translator = getEnumTranslator(keyType);
return new PropertiesManager(file,
getDefaultProperties(keyType,
translator),
translator,
new DefaultEvaluator(),
executor);
}
/**
* Build a new manager for the given properties file.
*
* @param
* the type of key used for the new manager
*
* @param file
* the file system location of the properties represented here
* @param keyType
* the enumeration of keys in the properties file
* @param translator
* the translator to convert between Enum names and property keys
* @param executor
* a service to handle potentially long running tasks, such as
* interacting with the file system
* @return a new manager
*/
public static & Defaultable> PropertiesManager newManager(File file,
Class keyType,
Translator translator,
ExecutorService executor)
{
return new PropertiesManager(file,
getDefaultProperties(keyType,
translator),
translator,
new DefaultEvaluator(),
executor);
}
/**
* Build a new manager for the given properties file.
*
* @param
* the type of key used for the new manager
*
* @param file
* the file system location of the properties represented here
* @param keyType
* the enumeration of keys in the properties file
* @param evaluator
* the evaluator to convert nested property references into fully
* evaluated strings
* @param executor
* a service to handle potentially long running tasks, such as
* interacting with the file system
* @return a new manager
*/
public static & Defaultable> PropertiesManager newManager(File file,
Class keyType,
Evaluator evaluator,
ExecutorService executor)
{
Translator translator = getEnumTranslator(keyType);
return new PropertiesManager(file,
getDefaultProperties(keyType,
translator),
translator,
evaluator,
executor);
}
/**
* Load values from a file.
*
* @param file
* the file containing default values
* @return a new properties instance loaded with values from the given file
* @throws IOException
* if there is an error while reading the given file
*/
public static Properties getProperties(File file) throws IOException
{
return getProperties(file.toURI().toURL());
}
/**
* Load values from a URL.
*
* @param url
* the URL containing default values
* @return a new properties instance loaded with values from the given URL
* @throws IOException
* if there is an error while reading the given URL
*/
public static Properties getProperties(URL url) throws IOException
{
Properties properties = new Properties();
InputStream inputStream = url.openStream();
try
{
properties.load(inputStream);
}
finally
{
inputStream.close();
}
return properties;
}
/**
* Retrieve a {@link Properties} instance that contains all of the default
* values defined for the given {@link Defaultable}.
*
* @param
* the key type whose default values are requested
* @param keyType
* the class that contains the appropriate defaults
* @param translator
* a translator to convert between key instances and property
* names
* @return a {@link Properties} instance containing the default values
* stored in the given key type
*/
public static & Defaultable> Properties getDefaultProperties(Class keyType,
Translator translator)
{
Properties defaults = new Properties();
for (T key : keyType.getEnumConstants())
{
defaults.setProperty(translator.getPropertyName(key),
key.getDefaultValue());
}
return defaults;
}
/**
* Create a translator that returns the string that it is given (no
* translation).
*
* @return the identity translator implementation
*/
public static Translator getIdentityTranslator()
{
return new Translator()
{
@Override
public String getPropertyName(String propertyKey)
{
return propertyKey;
}
@Override
public String getPropertyKey(String propertyName)
{
return propertyName;
}
};
}
/**
* Get a simple translator to convert back and forth between Enums and
* property names (keys).
*
* @param
* the type of Enum representing the properties
* @param enumType
* the Enum class used to represent the properties
* @return the Enum translator implementation
*/
public static > Translator getEnumTranslator(final Class enumType)
{
return new Translator()
{
@Override
public String getPropertyName(T propertyKey)
{
return propertyKey.name().toLowerCase().replace('_', '.');
}
@Override
public T getPropertyKey(String propertyName)
{
String enumName = propertyName.toUpperCase().replace('.', '_');
return Enum.valueOf(enumType, enumName);
}
};
}
/**
* Private constructor. This class implements a factory pattern to build
* {@link PropertiesManager managers} and can not be instantiated.
*/
private PropertiesManagers()
{
/*
* Factory pattern.
*/
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy