SessionVariableField.java

// 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.doris.qe;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.reflect.Field;
import java.util.Objects;

public class SessionVariableField implements Serializable {
    private transient Field field;

    public SessionVariableField(Field field) {
        this.field = field;
    }

    public Field getField() {
        return field;
    }

    private void writeObject(ObjectOutputStream out) throws IOException {
        out.defaultWriteObject();
        out.writeObject(field.getName());
        out.writeObject(field.getType());
    }

    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
        in.defaultReadObject();
        String fieldName = (String) in.readObject();
        Class<?> fieldType = (Class<?>) in.readObject();
        try {
            field = getField(fieldName, fieldType);
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        }
    }

    private Field getField(String fieldName, Class<?> fieldType) throws NoSuchFieldException {
        try {
            return SessionVariable.class.getDeclaredField(fieldName);
        } catch (NoSuchFieldException e) {
            Class<?> superclass = SessionVariable.class.getSuperclass();
            if (superclass != null) {
                return getField(fieldName, fieldType);
            }
            throw e;
        }
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null || getClass() != obj.getClass()) {
            return false;
        }
        SessionVariableField other = (SessionVariableField) obj;
        // 忽略 transient 字段的比较
        return Objects.equals(this.getField(), other.getField());
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(this.getField());
    }

}