org.apache.calcite.util.Compatible Maven / Gradle / Ivy
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/*
* 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.util;
import com.google.common.base.Function;
import com.google.common.collect.ImmutableSortedMap;
import com.google.common.collect.ImmutableSortedSet;
import com.google.common.collect.Maps;
import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.sql.Connection;
import java.util.Map;
import java.util.NavigableMap;
import java.util.NavigableSet;
import java.util.Set;
/** Compatibility layer.
*
* Allows to use advanced functionality if the latest JDK or Guava version
* is present.
*/
public interface Compatible {
Compatible INSTANCE = new Factory().create();
/** Same as Guava {@code Maps.asMap(set, function)} (introduced in
* Guava 14.0). */
Map asMap(Set set, Function function);
/** Converts a {@link com.google.common.collect.ImmutableSortedSet} to a
* {@link java.util.NavigableSet}. (In Guava 12 and later, ImmutableSortedSet
* implements NavigableSet.) */
NavigableSet navigableSet(ImmutableSortedSet set);
/** Converts a {@link com.google.common.collect.ImmutableSortedMap} to a
* {@link java.util.NavigableMap}. (In Guava 12 and later, ImmutableSortedMap
* implements NavigableMap.) */
NavigableMap navigableMap(ImmutableSortedMap map);
/** Converts a {@link Map} to a {@link java.util.NavigableMap} that is
* immutable. */
NavigableMap immutableNavigableMap(NavigableMap map);
/** Calls {@link java.sql.Connection}{@code .setSchema(String)}.
*
* This method is available in JDK 1.7 and above, and in
* {@link org.apache.calcite.jdbc.CalciteConnection} in all JDK versions. */
@SuppressWarnings("unused") @Deprecated // to be removed before 2.0
void setSchema(Connection connection, String schema);
/** Calls the {@link Method}.{@code getParameters()[i].getName()} method
* (introduced in JDK 1.8). */
String getParameterName(Method method, int i);
/** Creates the implementation of Compatible suitable for the
* current environment. */
class Factory {
Compatible create() {
return (Compatible) Proxy.newProxyInstance(
Compatible.class.getClassLoader(),
new Class[] {Compatible.class}, (proxy, method, args) -> {
if (method.getName().equals("asMap")) {
// Use the Guava implementation Maps.asMap if it is available
try {
//noinspection ConfusingArgumentToVarargsMethod
final Method guavaMethod = Maps.class.getMethod(
method.getName(), method.getParameterTypes());
return guavaMethod.invoke(null, args);
} catch (NoSuchMethodException e) {
Set set = (Set) args[0];
Function function = (Function) args[1];
return CompatibleGuava11.asMap(set, function);
}
}
if (method.getName().equals("navigableSet")) {
ImmutableSortedSet set = (ImmutableSortedSet) args[0];
return CompatibleGuava11.navigableSet(set);
}
if (method.getName().equals("navigableMap")) {
ImmutableSortedMap map = (ImmutableSortedMap) args[0];
return CompatibleGuava11.navigableMap(map);
}
if (method.getName().equals("immutableNavigableMap")) {
Map map = (Map) args[0];
ImmutableSortedMap sortedMap = ImmutableSortedMap.copyOf(map);
return CompatibleGuava11.navigableMap(sortedMap);
}
if (method.getName().equals("setSchema")) {
Connection connection = (Connection) args[0];
String schema = (String) args[1];
final Method method1 =
connection.getClass().getMethod("setSchema", String.class);
return method1.invoke(connection, schema);
}
if (method.getName().equals("getParameterName")) {
final Method m = (Method) args[0];
final int i = (Integer) args[1];
try {
final Method method1 =
m.getClass().getMethod("getParameters");
Object parameters = method1.invoke(m);
final Object parameter = Array.get(parameters, i);
final Method method3 =
parameter.getClass().getMethod("getName");
return method3.invoke(parameter);
} catch (NoSuchMethodException e) {
return "arg" + i;
}
}
return null;
});
}
}
}
// End Compatible.java