com.nordstrom.common.params.Params Maven / Gradle / Ivy
package com.nordstrom.common.params;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
/**
* This interface enables implementers to provide methods to support for concisely-defined parameters.
*/
public interface Params {
/**
* Get the defined parameters.
*
* @return optional map of named parameters
*/
Optional> getParameters();
/**
* This class defines a parameter object.
*/
static class Param {
private final String key;
private final Object val;
/**
* Constructor for parameter object.
*
* @param key parameter key
* @param val parameter value
*/
public Param(String key, Object val) {
if ((key == null) || key.isEmpty()) {
throw new IllegalArgumentException("[key] must be a non-empty string");
}
this.key = key;
this.val = val;
}
/**
* Get key of this parameter.
*
* @return parameter key
*/
public String getKey() {
return key;
}
/**
* Get value of this parameter.
*
* @return parameter value
*/
public Object getVal() {
return val;
}
/**
* Assemble a map of parameters.
*
* @param params array of {@link Param} objects; may be {@code null} or empty
* @return optional map of parameters (may be empty)
*/
public static Optional> mapOf(Param... params) {
if ((params == null) || (params.length == 0)) {
return Optional.empty();
}
Map paramMap = new HashMap<>();
for (Param param : params) {
paramMap.put(param.key, param.val);
}
return Optional.of(Collections.unmodifiableMap(paramMap));
}
/**
* Create a parameter object for the specified key/value pair.
*
* @param key parameter key (name)
* @param val parameter value
* @return parameter object
*/
public static Param param(String key, Object val) {
return new Param(key, val);
}
}
}