/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*
* C E D A R
* S O L U T I O N S "Software done right."
* S O F T W A R E
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*
* Copyright (c) 2013 Kenneth J. Pronovici.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the Apache License, Version 2.0.
* See LICENSE for more information about the licensing terms.
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*
* Author : Kenneth J. Pronovici <pronovic@ieee.org>
* Language : Java 6
* Project : Common Java Functionality
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
package com.cedarsolutions.util;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import com.cedarsolutions.exception.NotFoundException;
import com.google.gwt.i18n.client.Constants;
import com.google.gwt.i18n.client.Constants.DefaultBooleanValue;
import com.google.gwt.i18n.client.Constants.DefaultDoubleValue;
import com.google.gwt.i18n.client.Constants.DefaultFloatValue;
import com.google.gwt.i18n.client.Constants.DefaultIntValue;
import com.google.gwt.i18n.client.Constants.DefaultStringValue;
import com.google.gwt.i18n.client.Messages;
import com.google.gwt.i18n.client.Messages.DefaultMessage;
/**
* Reads GWT configuration on the server-side.
*
* <p>
* This is intended for use with GWT Constants and Messages interfaces. It
* looks at the default value and default message annotations on the
* interfaces, but does not interpret any of the underlying properties files
* that are used for translations. It only supports the more common
* configuration types (no string arrays or maps), and does not support any
* argument subsitution in messages. It just gives you back the value from the
* annotation.
* </p>
*
* <p>
* Clearly, this class is not a substitute for the real GWT functionality, but
* does at least allow for putting "shared" constants and user-facing messages
* in a single place. Pure server-side configuration should still be retrieved
* from a properties file via config classes.
* </p>
*
* @author Kenneth J. Pronovici <pronovic@ieee.org>
*/
public class GwtConfigUtils {
/** Get a Boolean constant from a GWT resource class. */
public Boolean getBoolean(Class<? extends Constants> clazz, String name) {
return (Boolean) get(clazz, ConstantType.BOOLEAN, name);
}
/** Get a Double constant from a GWT resource class. */
public Double getDouble(Class<? extends Constants> clazz, String name) {
return (Double) get(clazz, ConstantType.DOUBLE, name);
}
/** Get a Float constant from a GWT resource class. */
public Float getFloat(Class<? extends Constants> clazz, String name) {
return (Float) get(clazz, ConstantType.FLOAT, name);
}
/** Get a Integer constant from a GWT resource class. */
public Integer getInteger(Class<? extends Constants> clazz, String name) {
return (Integer) get(clazz, ConstantType.INTEGER, name);
}
/** Get a String constant from a GWT resource class. */
public String getString(Class<? extends Constants> clazz, String name) {
return (String) get(clazz, ConstantType.STRING, name);
}
/** Get a message string from a GWT resource class. */
public String getMessage(Class<? extends Messages> clazz, String name) {
return (String) get(clazz, name);
}
/** Get a mocked value of a particular type from a class. */
private Object get(Class<? extends Messages> clazz, String name) {
for (Method method : clazz.getMethods()) {
if (method.getName().equals(name)) {
return get(clazz, method);
}
}
throw new NotFoundException("Could not find: " + clazz.getCanonicalName() + "." + name + "()");
}
/** Get a mocked value of a message from a method. */
private Object get(Class<? extends Messages> clazz, Method method) {
for (Annotation annotation : method.getDeclaredAnnotations()) {
if (annotation instanceof DefaultMessage) {
return ((DefaultMessage) annotation).value();
}
}
throw new NotFoundException("Wrong type: " + clazz.getCanonicalName() + "." + method.getName() + "() is not a message");
}
/** Get a mocked value of a particular type from a class. */
private Object get(Class<? extends Constants> clazz, ConstantType type, String name) {
for (Method method : clazz.getMethods()) {
if (method.getName().equals(name)) {
return get(clazz, method, type);
}
}
throw new NotFoundException("Could not find: " + clazz.getCanonicalName() + "." + name + "()");
}
/** Get a mocked value of a particular type from a method. */
private Object get(Class<? extends Constants> clazz, Method method, ConstantType type) {
switch (type) {
case BOOLEAN:
for (Annotation annotation : method.getDeclaredAnnotations()) {
if (annotation instanceof DefaultBooleanValue) {
return ((DefaultBooleanValue) annotation).value();
}
}
break;
case DOUBLE:
for (Annotation annotation : method.getDeclaredAnnotations()) {
if (annotation instanceof DefaultDoubleValue) {
return ((DefaultDoubleValue) annotation).value();
}
}
break;
case FLOAT:
for (Annotation annotation : method.getDeclaredAnnotations()) {
if (annotation instanceof DefaultFloatValue) {
return ((DefaultFloatValue) annotation).value();
}
}
break;
case INTEGER:
for (Annotation annotation : method.getDeclaredAnnotations()) {
if (annotation instanceof DefaultIntValue) {
return ((DefaultIntValue) annotation).value();
}
}
break;
case STRING:
for (Annotation annotation : method.getDeclaredAnnotations()) {
if (annotation instanceof DefaultStringValue) {
return ((DefaultStringValue) annotation).value();
}
}
break;
}
throw new NotFoundException("Wrong type: " + clazz.getCanonicalName() + "." + method.getName() + "() is not " + type);
}
/** Available constant types. */
private enum ConstantType {
BOOLEAN,
DOUBLE,
FLOAT,
INTEGER,
STRING,
}
}