~~~ /** * Copyright 2009-2019 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 * * 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.ibatis.annotations; import java.lang.annotation.Documented; import java.lang.annotation.ElementType; import java.lang.annotation.Repeatable; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import org.apache.ibatis.type.JdbcType; import org.apache.ibatis.type.TypeHandler; import org.apache.ibatis.type.UnknownTypeHandler; /** * The annotation that specify a mapping definition for the constructor argument. * * @see ConstructorArgs * @author Clinton Begin */ @Documented //运行时的作用域 @Retention(RetentionPolicy.RUNTIME) //方法 @Target(ElementType.METHOD) //构造函数可重复 @Repeatable(ConstructorArgs.class) public @interface Arg { /** * Returns whether id column or not. * * @return {@code true} if id column; {@code false} if otherwise */ boolean id() default false; /** * Return the column name(or column label) to map to this argument. * * @return the column name(or column label) */ String column() default ""; /** * Return the java type for this argument. * * @return the java type */ Class<?> javaType() default void.class; /** * Return the jdbc type for column that map to this argument. * * @return the jdbc type */ JdbcType jdbcType() default JdbcType.UNDEFINED; /** * Returns the {@link TypeHandler} type for retrieving a column value from result set. * * @return the {@link TypeHandler} type */ Class<? extends TypeHandler> typeHandler() default UnknownTypeHandler.class; /** * Return the statement id for retrieving a object that map to this argument. * * @return the statement id */ String select() default ""; /** * Returns the result map id for mapping to a object that map to this argument. * * @return the result map id */ String resultMap() default ""; /** * Returns the parameter name for applying this mapping. * * @return the parameter name * @since 3.4.3 */ String name() default ""; /** * Returns the column prefix that use when applying {@link #resultMap()}. * * @return the column prefix * @since 3.5.0 */ String columnPrefix() default ""; } ~~~