org.glassfish.jersey.internal.util.PropertiesHelper Maven / Gradle / Ivy
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package org.glassfish.jersey.internal.util;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.Map;
/**
* Helper class containing convenience methods for reading
* {@code org.glassfish.jersey.server.ResourceConfig} and {@link javax.ws.rs.client.Configuration} properties.
*
* @author Martin Matula (martin.matula at oracle.com)
*/
public class PropertiesHelper {
/**
* Returns value of a specified property. If the property is not set or the real value type is not compatible with
* defaultValue type, the specified defaultValue is returned. Calling this method is equivalent to calling
* {@code PropertyHelper.getValue(properties, key, defaultValue, (Class) defaultValue.getClass())}
*
* @param properties Map of properties to get the property value from.
* @param key Name of the property.
* @param defaultValue Default value to be returned if the specified property is not set or cannot be read.
* @param Type of the property value.
* @return Value of the property or defaultValue.
*/
public static T getValue(Map properties, String key, T defaultValue) {
return getValue(properties, key, defaultValue, (Class) defaultValue.getClass());
}
/**
* Returns value of a specified property. If the property is not set or the real value type is not compatible with
* the specified value type, returns defaultValue.
*
* @param properties Map of properties to get the property value from.
* @param key Name of the property.
* @param defaultValue Default value of the property.
* @param type Type to retrieve the value as.
* @param Type of the property value.
* @return Value of the property or null.
*/
public static T getValue(Map properties, String key, T defaultValue, Class type) {
T value = getValue(properties, key, type);
if (value == null) {
value = defaultValue;
}
return value;
}
/**
* Returns value of a specified property. If the property is not set or the real value type is not compatible with
* the specified value type, returns null.
*
* @param properties Map of properties to get the property value from.
* @param key Name of the property.
* @param type Type to retrieve the value as.
* @param Type of the property value.
* @return Value of the property or null.
*/
public static T getValue(Map properties, String key, Class type) {
Object value = properties.get(key);
if (value == null) {
return null;
}
if (!type.isInstance(value)) {
// TODO: Move string value readers from server to common and utilize them here
final Constructor constructor = ReflectionHelper.getStringConstructor(type);
if (constructor != null) {
try {
return type.cast(constructor.newInstance(value));
} catch (Exception e) {
// calling the constructor wasn't successful - ignore and try valueOf()
}
}
final Method valueOf = ReflectionHelper.getValueOfStringMethod(type);
if (valueOf != null) {
try {
return type.cast(valueOf.invoke(null, value));
} catch (Exception e) {
// calling valueOf wasn't successful
}
}
// at this point we don't know what to return -> return null
// TODO: should also log warning
return null;
}
return type.cast(value);
}
}