数据库连接、Mybatis配置文件等代码

以下是一个简单的基于 MyBatis 的 Java 应用，包括数据库连接和 MyBatis 配置文件：

1. 数据库连接

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBUtil {
    private static final String URL = "jdbc:mysql://localhost:3306/mydatabase";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "password";

    public static Connection getConnection() {
        Connection conn = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
}

2. MyBatis 配置文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mydatabase"/>
                <property name="username" value="root"/>
                <property name="password" value="password"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/nxu/dao/AuthorMapper.xml"/>
    </mappers>
</configuration>

3. MyBatis DAO 接口

import java.util.List;

public interface AuthorMapper {
    List<Author> getAllAuthors();
    Author getAuthorById(int id);
    void addAuthor(Author author);
    void updateAuthor(Author author);
    void deleteAuthor(int id);
}

4. MyBatis DAO 映射文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.nxu.dao.AuthorMapper">
    <resultMap id="authorResultMap" type="Author">
        <id column="id" property="id"/>
        <result column="name" property="name"/>
        <result column="email" property="email"/>
        <result column="country" property="country"/>
    </resultMap>

    <select id="getAllAuthors" resultMap="authorResultMap">
        SELECT * FROM authors
    </select>

    <select id="getAuthorById" parameterType="int" resultMap="authorResultMap">
        SELECT * FROM authors WHERE id = #{id}
    </select>

    <insert id="addAuthor" parameterType="Author">
        INSERT INTO authors (name, email, country) VALUES (#{name}, #{email}, #{country})
    </insert>

    <update id="updateAuthor" parameterType="Author">
        UPDATE authors SET name=#{name}, email=#{email}, country=#{country} WHERE id=#{id}
    </update>

    <delete id="deleteAuthor" parameterType="int">
        DELETE FROM authors WHERE id=#{id}
    </delete>
</mapper>

以上就是一个简单的 MyBatis 应用的所有代码。注意，这只是一个示例，实际使用时需要根据自己的需求进行修改。