org.milyn.cdr.Parameter Maven / Gradle / Ivy
package org.milyn.cdr;
import java.util.List;
import org.milyn.delivery.ContentDeliveryConfig;
import org.w3c.dom.Element;
/**
* SmooksResourceConfiguration Parameter.
*
* Wrapper for a param. Handles decoding.
* @author tfennelly
*/
public class Parameter {
public static final String PARAM_TYPE_PREFIX = "param-type:";
private final String name;
String value;
private String type;
private Object objValue;
private Element xml;
/**
* Public constructor.
* @param name Parameter name.
* @param value Parameter value.
*/
public Parameter(String name, String value) {
if(name == null || (name = name.trim()).equals("")) {
throw new IllegalArgumentException("null or empty 'name' arg in constructor call.");
}
if(value == null) {
throw new IllegalArgumentException("null 'value' arg in constructor call.");
}
this.name = name;
this.value = value;
}
/**
* Public constructor.
* @param name Parameter name.
* @param value Parameter value.
*/
public Parameter(String name, Object value) {
if(name == null || (name = name.trim()).equals("")) {
throw new IllegalArgumentException("null or empty 'name' arg in constructor call.");
}
if(value == null) {
throw new IllegalArgumentException("null 'value' arg in constructor call.");
}
this.name = name;
this.value = value.toString();
this.objValue = value;
}
/**
* Public constructor.
* @param name Parameter name.
* @param value Parameter value.
* @param type Parameter type. This argument identifies the
* {@link ParameterDecoder} to use for decoding the param value.
*/
public Parameter(String name, String value, String type) {
this(name, value);
// null type attribute is OK - means no decoder is used on the value
this.type = type;
}
/**
* Get the parameter name.
* @return The parameter name.
*/
public String getName() {
return name;
}
/**
* Get the parameter type.
* @return The parameter type.
*/
public String getType() {
return type;
}
/**
* Get the parameter value "undecoded".
* @return Parameter value.
*/
public String getValue() {
return value;
}
/**
* Get the parameter value "decoded" into an Object.
*
* Uses the supplied deliveryConfig to get the {@link ParameterDecoder}
* implementation to be used to decode the parameter value. Looks up the
* {@link ParameterDecoder} using the parameter type - selector="decoder-<type>".
* @param deliveryConfig Requesting device {@link ContentDeliveryConfig}.
* @return Decoded value.
* @throws ParameterDecodeException Unable to decode parameter value.
*/
public Object getValue(ContentDeliveryConfig deliveryConfig) throws ParameterDecodeException {
if(objValue == null) {
synchronized (value) {
if(objValue == null) {
if(type == null) {
objValue = value;
} else {
List decoders = deliveryConfig.getObjects(PARAM_TYPE_PREFIX + type);
if(!decoders.isEmpty()) {
try {
ParameterDecoder paramDecoder = (ParameterDecoder)decoders.get(0);
objValue = paramDecoder.decodeValue(value);
} catch(ClassCastException cast) {
throw new ParameterDecodeException("Configured ParameterDecoder '" + PARAM_TYPE_PREFIX + type + "' for device must be of type " + ParameterDecoder.class);
}
} else {
throw new ParameterDecodeException("ParameterDecoder '" + PARAM_TYPE_PREFIX + type + "' not defined for requesting device.");
}
}
}
}
}
return objValue;
}
/**
* Get the object value associated with this parameter.
* @return The object value, or null if not set.
*/
public Object getObjValue() {
return objValue;
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return value;
}
/**
* Set the DOM element node associated with the parameter definition.
*
* Only relevant for XML based configs.
*
* @param xml Parameter configuration xml.
*/
public Parameter setXML(Element xml) {
this.xml = xml;
return this;
}
/**
* Get the DOM element node associated with the parameter definition.
*
* Only relevant for XML based configs.
*
* @return Parameter configuration xml.
*/
public Element getXml() {
return xml;
}
}