MyBatis学习-偏实践（单独MyBatis项目）

准备先把MyBatis搞熟悉了，然后把SpringMVC搞熟悉了。

MyBatis的材料，除了我之前自己实验的

http://www.cnblogs.com/charlesblc/p/5906431.html

还有这个：

http://www.cnblogs.com/charlesblc/p/5939505.html

现在主要参考以下两个：

http://www.cnblogs.com/charlesblc/p/5906431.html （转载自 http://www.yihaomen.com/article/java/302.htm）

http://limingnihao.iteye.com/blog/781671

可能还有这个： http://www.cnblogs.com/xdp-gacl/p/4261895.html

利用Idea重新开始搭建：

按照这个页面：http://www.yihaomen.com/article/java/303.htm 写了一些代码。（整理好的版本在后面给出）

运行， 开始没有找到配置文件：

java.io.IOException: Could not find resource /Users/baidu/Documents/Data/Work/Code/Self/mybatis-demo/target/classes/resources/Mybatis.xml

本来以为需要配置才能把Resources里面的文件放到编译目标目录。上网查之后发现是自动放的。后来发现文件貌似是在：

/Users/baidu/Documents/Data/Work/Code/Self/mybatis-demo/target/classes

然后用了

String configFile = Class.class.getClass().getResource("/").getPath().toString() + "Mybatis.xml";
reader = Resources.getResourceAsReader(configFile);

还是报错找不到，但是报错信息中的文件，是实际存在的。

怀疑是不是不能用绝对路径，所以改了一下：

reader = Resources.getResourceAsReader("Mybatis.xml");

发现可以了。哈哈。

整理代码结构如下，其中红框内的是实际用到的文件：

在开发之前，在数据库中建立一个表。注意其中语句\G表示Gracefully显示，垂直显示。另外，如果结果出现乱码，查看之前Mysql修正乱码的帖子。

mysql> use springdemo;
Database changed
mysql> show create table user \G
*************************** 1. row ***************************
       Table: user
Create Table: CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `nickname` varchar(45) DEFAULT NULL,
  `password` varchar(45) DEFAULT NULL,
  `first_name` varchar(45) DEFAULT NULL,
  `last_name` varchar(45) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8
1 row in set (0.00 sec)

mysql> select * from user;
+----+------------+----------+------------+-----------+
| id | nickname   | password | first_name | last_name |
+----+------------+----------+------------+-----------+
|  1 | chaoliu    | 321      | chao       | liu       |
|  3 | micro      | 123      | bill       | gates     |
|  5 | helloworld | 123      | hello      | world     |
|  7 | 你好     | 123      | 中        | 文       |
+----+------------+----------+------------+-----------+
4 rows in set (0.00 sec)

然后看工程里面各个文件：

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.myapp</groupId>
    <artifactId>mybatis-demo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <!-- mybatis版本号 -->
        <mybatis.version>3.2.8</mybatis.version>

        <!-- mysql驱动版本号 -->
        <mysql-driver.version>5.1.29</mysql-driver.version>

        <!-- log4j日志包版本号 -->
        <slf4j.version>1.7.18</slf4j.version>
        <log4j.version>1.2.17</log4j.version>

    </properties>

    <dependencies>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
        </dependency>

        <!-- 添加mysql驱动依赖 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql-driver.version}</version>
        </dependency>

        <!-- 添加日志相关jar包 -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>${slf4j.version}</version>
        </dependency>

    </dependencies>

</project>

Mybatis.xml

<?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>
    <typeAliases>
        <typeAlias alias="User" type="com.myapp.mybatis.model.User"/>
    </typeAliases>

    <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://[host]:8306/springdemo" />
                <property name="username" value="root"/>
                <property name="password" value="[password]"/>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper resource="User.xml"/>
    </mappers>
</configuration>

User.xml

<?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.myapp.mybatis.models.UserMapper">
    <select id="selectUserByID" parameterType="int" resultType="User">
        select * from `user` where id = #{id}
    </select>
</mapper>

User.java

package com.myapp.mybatis.model;

/**
 * Created by baidu on 16/10/18.
 */
public class User {
    private int id;
    private String nickname;

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getNickName() {
        return nickname;
    }
    public void setUserName(String nickName) {
        this.nickname = nickName;
    }
}

Test.java

package com.myapp.mybatis.test;

import com.myapp.mybatis.model.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.apache.log4j.lf5.util.Resource;

import java.io.Reader;

/**
 * Created by baidu on 16/10/18.
 */
public class Test {
    private static SqlSessionFactory sqlSessionFactory;
    private static Reader reader;

    static {
        try {
            //String configFile = Class.class.getClass().getResource("/").getPath().toString() + "Mybatis.xml";
            reader = Resources.getResourceAsReader("Mybatis.xml");
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static SqlSessionFactory getSession() {
        return sqlSessionFactory;
    }

    public static void main(String[] args) {
        SqlSession session = sqlSessionFactory.openSession();
        try {
            User user = (User)
                    session.selectOne("com.myapp.mybatis.models.UserMapper.selectUserByID", 1);
            System.out.printf("Get user id: %d, nickname: %s\n", user.getId(), user.getNickName());
        } finally {
            session.close();
        }
    }
}

然后运行，用基本的java环境运行即可。运行结果如下：

/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/bin/java -Didea.launcher.port=7532 "-Didea.launcher.bin.path=/Applications/IntelliJ IDEA.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath "/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/deploy.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/cldrdata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/dnsns.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/jaccess.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/jfxrt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/localedata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/nashorn.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/sunec.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/zipfs.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/javaws.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/jfxswt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/management-agent.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/plugin.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/ant-javafx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/dt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/javafx-mx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/jconsole.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/packager.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/sa-jdi.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/tools.jar:/Users/baidu/Documents/Data/Work/Code/Self/mybatis-demo/target/classes:/Users/baidu/.m2/repository/org/mybatis/mybatis/3.2.8/mybatis-3.2.8.jar:/Users/baidu/.m2/repository/mysql/mysql-connector-java/5.1.29/mysql-connector-java-5.1.29.jar:/Users/baidu/.m2/repository/log4j/log4j/1.2.17/log4j-1.2.17.jar:/Users/baidu/.m2/repository/org/slf4j/slf4j-api/1.7.18/slf4j-api-1.7.18.jar:/Users/baidu/.m2/repository/org/slf4j/slf4j-log4j12/1.7.18/slf4j-log4j12-1.7.18.jar:/Applications/IntelliJ IDEA.app/Contents/lib/idea_rt.jar" com.intellij.rt.execution.application.AppMain com.myapp.mybatis.test.Test
log4j:WARN No appenders could be found for logger (org.apache.ibatis.logging.LogFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Get user id: 3, nickname: micro

Process finished with exit code 0