JavaTypeResolver.java

/*
 *    Copyright 2006-2026 the original author or authors.
 *
 *    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
 *
 *       https://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.mybatis.generator.api;

import java.util.List;
import java.util.Optional;
import java.util.Properties;

import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;
import org.mybatis.generator.config.Context;

/**
 * This interface describes methods that are required in any Java type resolver.
 * A Java type resolver is used to make a default translation between a JDBC
 * type as returned from the database introspection process, and a Java type.
 *
 * @author Jeff Butler
 */
public interface JavaTypeResolver {
    /**
     * Adds properties for this instance from any properties configured in the
     * JavaTypeResolverConfiguration.
     *
     * <p>This method will be called before any of the get methods.
     *
     * @param properties All properties from the configuration
     */
    void addConfigurationProperties(Properties properties);

    /**
     * Sets the instance of the Context object associated with this instance.
     *
     * <p>This method will be called before any of the get methods.
     *
     * @param context The current Context
     */
    void setContext(Context context);

    /**
     * The generator will supply a list to this method. The implementation class may add strings to the list that will
     * be treated as warning messages and displayed to the user. The concept of a warning is that code generation can
     * continue, but that the results may not be what is expected.
     *
     * @param warnings warnings
     */
    void setWarnings(List<String> warnings);

    /**
     * Calculates and returns the type information that should be associated with
     * this column based on the jdbc type, length, and scale of the column.
     *
     * @param introspectedColumn the column whose type information needs to be calculated
     * @return the calculated type information, or empty if this is an unsupported type.
     *     If empty, we will set the JDBC type to OTHER and the Java type to Object and issue a warning
     *     unless the column is ignored or otherwise overridden
     */
    Optional<JdbcTypeInformation> calculateTypeInformation(IntrospectedColumn introspectedColumn);

    record JdbcTypeInformation(String jdbcTypeName, FullyQualifiedJavaType fullyQualifiedJavaType) {
        public JdbcTypeInformation withJavaType(FullyQualifiedJavaType fullyQualifiedJavaType) {
            return new JdbcTypeInformation(jdbcTypeName, fullyQualifiedJavaType);
        }
    }
}