db.sql.api.impl.tookit.LambdaUtil Maven / Gradle / Ivy
/*
* Copyright (c) 2022-2023, Mybatis-Flex ([email protected]).
*
* Licensed 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 db.sql.api.impl.tookit;
import db.sql.api.GetterFun;
import org.apache.ibatis.util.MapUtil;
import java.lang.invoke.SerializedLambda;
import java.lang.reflect.Method;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
public final class LambdaUtil {
private static final Map LAMBDA_GETTER_FIELD_MAP = new ConcurrentHashMap<>(65535);
private static final Map> CLASS_MAP = new ConcurrentHashMap();
private LambdaUtil() {
}
public static String getName(GetterFun getter) {
return getFieldInfo(getter).getName();
}
private static LambdaFieldInfo getLambdaFieldInfo(SerializedLambda serializedLambda, ClassLoader classLoader) {
Class type = getClass(serializedLambda, classLoader);
String methodName = serializedLambda.getImplMethodName();
String fieldName = PropertyNamer.methodToProperty(methodName);
return new LambdaFieldInfo(type, fieldName);
}
public static LambdaFieldInfo getFieldInfo(GetterFun getter) {
return LAMBDA_GETTER_FIELD_MAP.computeIfAbsent(getter, (key) -> getLambdaFieldInfo(getSerializedLambda(getter), getter.getClass().getClassLoader()));
}
private static SerializedLambda getSerializedLambda(GetterFun getter) {
try {
Method method = getter.getClass().getDeclaredMethod("writeReplace");
method.setAccessible(Boolean.TRUE);
return (SerializedLambda) method.invoke(getter);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
private static Class getClass(SerializedLambda lambda, ClassLoader classLoader) {
String classNamePath = getClassNamePath(lambda);
return (Class) MapUtil.computeIfAbsent(CLASS_MAP, classNamePath, key -> {
try {
return Class.forName(getClassName(key), false, classLoader);
} catch (ClassNotFoundException e) {
throw new RuntimeException(e);
}
});
}
private static String getClassName(String classNamePath) {
return classNamePath.replace("/", ".");
}
private static String getClassNamePath(SerializedLambda lambda) {
String type = lambda.getInstantiatedMethodType();
return type.substring(2, type.indexOf(";"));
}
public static void main(String[] args) {
System.out.println(getName(LambdaFieldInfo::getName));
System.out.println(getName(LambdaFieldInfo::getName));
System.out.println(LAMBDA_GETTER_FIELD_MAP.size());
}
public static class LambdaFieldInfo {
private final Class type;
private final String name;
public LambdaFieldInfo(Class type, String name) {
this.type = type;
this.name = name;
}
public Class getType() {
return type;
}
public String getName() {
return name;
}
}
}