Idea中maven环境下搭建MyBatis项目（一）
1、选择Maven框架下的webapp
1.1 添加新节点：archetypeCatalog=internal
1.2 或者在settings------->Build,Execution,Deployment——>Maven——>VM Options设置 -DarchetypeCatalog=internal
2、在Maven的pom文件中引入MyBatis需要用的jar包：
创建对应的java项目，引入需要的mybatis需要的jar，以及连接mysql数据库的jar!
asm-3.3.1.jar:操作Javaj字节码的类库
cglib-2.2.2.jar:用来动态集成Java类或实现接口
commons-logging-1.1.1.jar:用于通用日志处理
javassist-3.17.1-GA.jar:分析、编辑和创建Java字节码的类库
log4j-1.2.17.jar:日志系统
slf4j-api-1.7.5.jar:日志系统的封装，对外提供统一的API接口
slf4j-log4j12-1.7.5.jar:slf4j对log4j的对应驱动，完成slf4j绑定log4j
mybatis-3.2.2.jar
mysql-connector-java-5.1.7-bin.jar/3
<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/maven-v4_0_0.xsd"> <parent> <artifactId>Book_08</artifactId> <groupId>cn.alexander</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>MyBatis</artifactId> <packaging>war</packaging> <name>MyBatis Maven Webapp</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.3</version> <scope>test</scope> </dependency> <!--配置mybatis需要的依赖包--> <dependency> <groupId>asm</groupId> <artifactId>asm</artifactId> <version>3.3.1</version> </dependency> <dependency> <groupId>cglib</groupId> <artifactId>cglib</artifactId> <version>2.2.2</version> </dependency> <dependency> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> <version>1.1.1</version> </dependency> <dependency> <groupId>org.javassist</groupId> <artifactId>javassist</artifactId> <version>3.17.1-GA</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.6</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.7</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.5</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.5</version> <scope>test</scope> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.3.0</version> </dependency> </dependencies> <build> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.xml</include> </includes> </resource> </resources> </build> </project>
3、创建MyBatis核心配置文件mybatis-config.xml
MyBatis核心配置文件主要用于配置数据库连接和MyBatis运行时所需的各种特性，包含了设置和影响MyBatis行为的属性。
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTDConfig 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <properties resource="jdbc.properties"></properties> <settings> <setting name="lazyLoadingEnabled" value="true"/> <setting name="aggressiveLazyLoading" value="true"></setting> </settings> <!-- <settings> <setting name="autoMappingBehavior" value="NONE"/> </settings>--> <typeAliases> <package name="cn.alexander.entity"></package> </typeAliases> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="${jdbc.driver}"/> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> </dataSource> </environment> </environments> <mappers> <!-- <mapper resource="cn/alexander/dao/IStudentDAO.xml"/>--> <package name="cn.alexander.dao"></package> </mappers> </configuration>
4、创建数据库表
5、在idea中创建实体类
package cn.alexander.entity; import java.io.Serializable; public class Dept implements Serializable { private Integer deptno; private String deptname; public Integer getDeptno() { return deptno; } public void setDeptno(Integer deptno) { this.deptno = deptno; } public String getDeptname() { return deptname; } public void setDeptname(String deptname) { this.deptname = deptname; } public Dept(Integer deptno, String deptname) { this.deptno = deptno; this.deptname = deptname; } public Dept(String deptname) { this.deptname = deptname; } public Dept() { } @Override public String toString() { return "Dept{" + "deptno=" + deptno + ", deptname='" + deptname + '\'' + '}'; } }
6、创建接口
package cn.alexander.dao; import cn.alexander.entity.Dept; import java.util.List; public interface IDeptDAO { // 查询所有的部门 public List<Dept> findAll(); }
7、创建接口的实现类
7.1使用单例创建seession
package cn.alexander.util; 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 java.io.IOException; import java.io.InputStream; /** * SqlSessionFactory的单例类 */ public class SessionFactoryUtil { // 创建需要单例的对象实例 private static SqlSessionFactory sessionFactory; // 私有化构造 private SessionFactoryUtil(){} // 对外提供访问接口 public static synchronized SqlSession getSession(){ try { InputStream stream = Resources.getResourceAsStream("mybatis-config.xml"); // 判断SqlSessionFactory是否为空，如果为空则创建 if(sessionFactory==null){ sessionFactory = new SqlSessionFactoryBuilder().build(stream); } } catch (IOException e) { e.printStackTrace(); } return sessionFactory.openSession(); } }
7.2通过session实现方法
package cn.alexander.dao; import cn.alexander.entity.Dept; import cn.alexander.util.SessionFactoryUtil; import org.apache.ibatis.session.SqlSession; import java.util.List; public class IDeptDAOImpl implements IDeptDAO { public List<Dept> findAll() { // 获取session SqlSession session = null; List<Dept> depts = null; try{ session = SessionFactoryUtil.getSession(); IDeptDAO mapper = session.getMapper(IDeptDAO.class); depts = mapper.findAll(); }catch (Exception e){ e.printStackTrace(); }finally { session.close(); } return depts; } }
8、接口对应的配置文件
<?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"> <!--映射文件的根节点 namespace --> <mapper namespace="cn.alexander.dao.IDeptDAO"> <select id="findAll" resultType="Dept"> select * from dept </select> </mapper>
修改pom.xml中的build节点。保证即使不在resources文件夹下的配置文件也能被读取
<build> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.xml</include> </includes> </resource> </resources> </build>
9、主配置关联小配置
在mybatis-config.xml中用mappers节点使主配置关联到小配置
<mappers> <!-- <mapper resource="cn/alexander/dao/IStudentDAO.xml"/>--> <package name="cn.alexander.dao"></package> </mappers>
10、编写测试类
package cn.alexander.test; import cn.alexander.dao.IDeptDAO; import cn.alexander.dao.IDeptDAOImpl; import cn.alexander.entity.Dept; import org.apache.log4j.Logger; import org.junit.Test; import java.util.List; public class Test20170923 { Logger logger = Logger.getLogger(Test20170923.class); @Test public void findAll(){ IDeptDAO iDeptDAO = new IDeptDAOImpl(); List<Dept> depts = iDeptDAO.findAll(); logger.debug(depts); } }
11、测试类运行结果：
