org.apache.calcite.avatica.AvaticaUtils Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file 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, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.calcite.avatica;
import java.util.AbstractList;
import java.util.List;
/** Avatica utilities. */
public class AvaticaUtils {
private AvaticaUtils() {}
/**
* Does nothing with its argument. Call this method when you have a value
* you are not interested in, but you don't want the compiler to warn that
* you are not using it.
*/
public static void discard(Object o) {
if (false) {
discard(o);
}
}
/**
* Adapts a primitive array into a {@link List}. For example,
* {@code asList(new double[2])} returns a {@code List<Double>}.
*/
public static List primitiveList(final Object array) {
// REVIEW: A per-type list might be more efficient. (Or might not.)
return new AbstractList() {
public Object get(int index) {
return java.lang.reflect.Array.get(array, index);
}
public int size() {
return java.lang.reflect.Array.getLength(array);
}
};
}
/**
* Converts a camelCase name into an upper-case underscore-separated name.
* For example, {@code camelToUpper("myJdbcDriver")} returns
* "MY_JDBC_DRIVER".
*/
public static String camelToUpper(String name) {
StringBuilder buf = new StringBuilder();
for (int i = 0; i < name.length(); i++) {
char c = name.charAt(i);
if (Character.isUpperCase(c)) {
buf.append('_');
} else {
c = Character.toUpperCase(c);
}
buf.append(c);
}
return buf.toString();
}
/**
* Converts an underscore-separated name into a camelCase name.
* For example, {@code uncamel("MY_JDBC_DRIVER")} returns "myJdbcDriver".
*/
public static String toCamelCase(String name) {
StringBuilder buf = new StringBuilder();
int nextUpper = -1;
for (int i = 0; i < name.length(); i++) {
char c = name.charAt(i);
if (c == '_') {
nextUpper = i + 1;
continue;
}
if (nextUpper == i) {
c = Character.toUpperCase(c);
} else {
c = Character.toLowerCase(c);
}
buf.append(c);
}
return buf.toString();
}
}
// End AvaticaUtils.java