mybatis入门_动力节点Java学院整理

本文为大家分享了mybatis入门学习资料，供大家参考，具体内容如下

所需要用到的其他工具或技术:
项目管理工具 : Maven
测试运行工具 : Junit
数据库 : Derby

废话不多说,直接代码
Maven Dependencies:

<dependencies>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.2.7</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.9</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.apache.derby</groupId>
      <artifactId>derby</artifactId>
      <version>10.10.2.0</version>
    </dependency>
    <dependency>
      <groupId>org.apache.derby</groupId>
      <artifactId>derbyclient</artifactId>
      <version>10.10.2.0</version>
    </dependency>
  </dependencies>

SQL 建表及数据插入:

CREATE TABLE USER_TEST_TB(
ID INT PRIMARY KEY,
USERNAME VARCHAR(20) NOT NULL,
PASSWORD VARCHAR(20) NOT NULL,
NICKNAME VARCHAR(20) NOT NULL
); 

INSERT INTO USER_TEST_TB VALUES(1,'1st','111','Jack');
INSERT INTO USER_TEST_TB VALUES(2,'2nd','222','Rose');
INSERT INTO USER_TEST_TB VALUES(3,'3rd','333','Will');

Mybatis配置文件 src/main/resource源目录下
test-mybatis-configuration.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>
  <properties>
    <property name="driver" value="org.apache.derby.jdbc.ClientDriver" />
    <property name="url"
      value="jdbc:derby://localhost:1527/freud;create=true" />
  </properties>
  <environments default="development">
    <environment id="development">
      <transactionManager type="JDBC" />
      <dataSource type="POOLED">
        <property name="driver" value="${driver}" />
        <property name="url" value="${url}" />
      </dataSource>
    </environment>
  </environments>
  <mappers>
    <!-- <mapper class="com.freud.practice.UserMapper" /> -->
    <mapper resource="com/freud/practice/UserMapper.xml" />
  </mappers>
</configuration>

UserMapper.xml  Mapper文件（src/main/java/com.freud.practice目录下）

<?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.freud.practice.UserMapper">
  <select id="getUser" resultType="com.freud.practice.User">
    select *
    from USER_TEST_TB
  </select>
</mapper>

User.Java对象类（src/main/java/com.freud.practice目录下）

package com.freud.practice; 

public class User
{ 

  private Integer id; 

  private String username; 

  private String password; 

  private String nickname; 

  public Integer getId()
  {
    return id;
  } 

  public void setId(Integer id)
  {
    this.id = id;
  } 

  public String getUsername()
  {
    return username;
  } 

  public void setUsername(String username)
  {
    this.username = username;
  } 

  public String getPassword()
  {
    return password;
  } 

  public void setPassword(String password)
  {
    this.password = password;
  } 

  public String getNickname()
  {
    return nickname;
  } 

  public void setNickname(String nickname)
  {
    this.nickname = nickname;
  } 

}

UserMapper.java Mapper类（src/main/java/com.freud.practice目录下）

package com.freud.practice; 

import java.util.List;
import org.apache.ibatis.annotations.Select; 

public interface UserMapper
{
  //@Select("SELECT * FROM USER_TEST_TB")
  public List<User> getUser();
}

测试类TestMyBatis.java（src/test/java/com.freud.practice目录下）

package com.freud.practice; 

import java.io.InputStream;
import java.text.MessageFormat;
import java.util.List; 

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test; 

public class TestMyBatis
{ 

  private String source; 

  private InputStream inputStream; 

  private SqlSessionFactory sqlSessionFactory; 

  @Before
  public void setUp()
  {
    source = "test-mybatis-configuration.xml";
  } 

  @Test
  public void testXMLConfingureSessionFactory()
  {
    try
    {
      inputStream = TestMyBatis.class.getClassLoader().getResourceAsStream(source);
      sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
      SqlSession session = sqlSessionFactory.openSession(); 

      List<User> users = (List) session.selectList("com.freud.practice.UserMapper.getUser");
      System.out.println("Query by XML configuration...");
      this.printUsers(users); 

      UserMapper userMapper = session.getMapper(UserMapper.class);
      System.out.println("\r\nQuery by annotation configuration...");
      this.printUsers(userMapper.getUser()); 

    }
    catch (Exception e)
    {
      e.printStackTrace();
    }
  } 

  private void printUsers(final List<User> users)
  {
    int count = 0; 

    for (User user : users)
    {
      System.out.println(MessageFormat.format("==User[{0}]=================", ++count));
      System.out.println("User Id: " + user.getId());
      System.out.println("User UserName: " + user.getUsername());
      System.out.println("User Password: " + user.getPassword());
      System.out.println("User nickname: " + user.getNickname());
    }
  }
}

以上是使用XML作为Mapper配置文件的一个入门，其实Mybatis还支持Annotation的方式，具体操作如下：

1. 打开UserMapper.java中的注释。
2. 打开test-mybatis-configuration.xml中的注释，并注释掉现有的Mapper
3. 删除UserMapper.xml文件

这种是Mybatis的Annotation方式的Mapper配置。个人比较偏向于XML方式，所以后续的教程会更倾向于XML配置的方式来写。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。