org.apache.struts.config.BaseConfig Maven / Gradle / Ivy
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* to you 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,
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*/
package org.apache.struts.config;
import java.io.Serializable;
import java.util.Enumeration;
import java.util.Properties;
/**
* A abstract base class for all config classes. Provide basic support
* for arbitrary properties
*
* @since Struts 1.3
*/
public abstract class BaseConfig implements Serializable {
/**
* Indicates if configuration of this component been completed. TODO
* change protected to private and use methods provided by extenders?
*/
protected boolean configured = false;
/**
* A map of arbitrary properties configured for this component.
*
* @since Struts 1.3
*/
private Properties properties = new Properties();
/**
* Freeze the configuration of this action.
*/
public void freeze() {
configured = true;
}
/**
* Throw IllegalStateException if configuration is frozen.
*
* @throws IllegalStateException if configuration is frozen
*/
public void throwIfConfigured() {
if (configured) {
throw new IllegalStateException("Configuration is frozen");
}
}
/**
* Set an arbitary key/value pair which can be retrieved by this
* config class. This facility should eliminate many use cases for
* subclassing *Config classes by providing a mechanism to
* pass any amount of arbitrary configuration information into an config
* class.
This method must not be called after configuration is
* complete, or an IllegalStateException will be thrown.
*
* Example
*
* <action path="/example" type="com.example.MyAction">
* <set-property key="foo" property="bar" />
* </action>
*
*
* @param key the key by which this value will be retrieved
* @param value the value to store with the supplied key
* @throws IllegalStateException if this module configuration has been
* frozen
* @since Struts 1.3
*/
public void setProperty(String key, String value) {
throwIfConfigured();
properties.setProperty(key, value);
}
/**
* Return the property-value for the specified key, if any; otherwise
* return null.
*
* @param key a key specified in the struts-config file
* @return the value stored with the supplied key
* @since Struts 1.3
*/
public String getProperty(String key) {
return properties.getProperty(key);
}
/**
* Return the entire set of properties configured for this object. At
* this time, this only needs to be exposed to support inheritance, so
* choosing a conservative access modifier ("protected").
*
* @return set of properties configured for this object
*/
protected Properties getProperties() {
return this.properties;
}
/**
* Set the entire set of properties configured for this object. At this
* time, this only needs to be exposed to support inheritance, so choosing
* a conservative access modifier ("protected").
*/
protected void setProperties(Properties properties) {
this.properties = properties;
}
/**
* Compare the properties of this config with that of the given and
* copy those that are not present. This method is used by subclasses
* that support configuration inheritance.
*
* @param baseConfig The config object to copy properties from.
*/
protected void inheritProperties(BaseConfig baseConfig) {
throwIfConfigured();
// Inherit forward properties
Properties baseProperties = baseConfig.getProperties();
Enumeration keys = baseProperties.propertyNames();
while (keys.hasMoreElements()) {
String key = (String) keys.nextElement();
// Check if we have this property before copying it
String value = this.getProperty(key);
if (value == null) {
value = baseProperties.getProperty(key);
setProperty(key, value);
}
}
}
/**
* Return a copy of the properties held by this object.
*/
protected Properties copyProperties() {
Properties copy = new Properties();
Enumeration keys = properties.propertyNames();
while (keys.hasMoreElements()) {
String key = (String) keys.nextElement();
copy.setProperty(key, properties.getProperty(key));
}
return copy;
}
}