使用IDEA Maven搭建mybatis 和遇到的问题
我只是一个愚人…
项目目录结构
数据库
drop table if exists tb_user;
create table tb_user (
id int(11) primary key auto_increment,
name varchar(18) default null,
sex char(2) default null,
age int(11) default null
);
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>org.fkit</groupId>
<artifactId>Hellobatis</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.44</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13-beta-2</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
</dependencies>
<build>
<finalName>Hellobatis</finalName>
<resources>
<resource>
<directory>${basedir}/src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
</resource>
<resource>
<directory>${basedir}/src/main/resources</directory>
</resource>
</resources>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
</project>
mybatis-config.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">
<!-- XML 配置文件包含对 MyBatis 系统的核心设置 -->
<configuration>
<!-- 指定 MyBatis 所用日志的具体实现 -->
<settings>
<setting name="logImpl" value="LOG4J"/>
</settings>
<environments default="mysql">
<!-- 环境配置，即连接的数据库。 -->
<environment id="mysql">
<!-- 指定事务管理类型，type="JDBC"指直接简单使用了JDBC的提交和回滚设置 -->
<transactionManager type="JDBC"/>
<!-- dataSource指数据源配置，POOLED是JDBC连接对象的数据源连接池的实现。 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=UTF-8&useSSL=false"/>
<property name="username" value="root"/>
<property name="password" value="123456"/>
</dataSource>
</environment>
</environments>
<!-- mappers告诉了MyBatis去哪里找持久化类的映射文件 -->
<mappers>
<mapper resource="org/fkit/mapper/UserMapper.xml"/>
</mappers>
</configuration>
log4j.properties
# Global logging configuration
log4j.rootLogger=ERROR, stdout
# MyBatis logging configuration...
log4j.logger.org.fkit.mapper.UserMapper=DEBUG
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] %m%n
UserMapper.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">
<!-- namespace指用户自定义的命名空间。 -->
<mapper namespace="org.fkit.mapper.UserMapper">
<!--
id="save"是唯一的标示符
parameterType属性指明插入时使用的参数类型
useGeneratedKeys="true"表示使用数据库的自动增长策略
-->
<insert id="save" parameterType="org.fkit.domain.User" useGeneratedKeys="true">
INSERT INTO TB_USER(name,sex,age)
VALUES(#{name},#{sex},#{age})
</insert>
</mapper>
User.java
package org.fkit.domain;
import java.io.Serializable;
public class User implements Serializable{
private static final long serialVersionUID = 1L;
// 用户标识
private Integer id;
// 用户姓名
private String name;
// 用户性别
private String sex;
// 用户年龄
private Integer age;
// 无参数构造器
public User() {
super();
}
// 有参数构造器
public User( String name, String sex, Integer age) {
super();
this.name = name;
this.sex = sex;
this.age = age;
}
// setter和getter方法
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", sex=" + sex + ", age="
+ age + "]";
}
}
MyBatisTest.java
package test;
import java.io.InputStream;
import org.fkit.domain.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;
public class MyBatisTest {
public static void main(String[] args) {
SqlSession sqlSession = null;
try (
InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
){
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder()
.build(is);
sqlSession = sqlSessionFactory.openSession();
User user = new User("adin", "女", 26);
sqlSession.insert("org.fkit.mapper.UserMapper.save", user);
sqlSession.commit();
} catch (Exception e) {
e.printStackTrace();
}finally{
try {
if(sqlSession != null) sqlSession.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
运行结果
遇到的问题
1 . Log4j提示类找不到
原因:不明,在External Libraries中没有Log4j类
解决:
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
<type>bundle</type>
</dependency>
在pom.xml依赖中去掉
<type>bundle</type>
后正常,External Libraries出现有Log4j类
2 . Idea中 idea language level始终是1.5的问题
原因: baidu了下，发现问题出现在了pom.xml文件的配置上，pom没有相关配置时，maven项目默认是会选择1.5版本的，所以在配置文件中，加上下面的代码即可。
解决:
<build>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
参考:
Idea搭建maven mybatis工程，并实现最简单的数据库连接
Idea中 idea language level始终是1.5的问题
Spring + MyBatis 企业停用实战 (第二版 ) - 疯狂软件 编著