iBatis，带一小例子

最新推荐文章于 2021-02-16 04:38:52 发布

原创最新推荐文章于 2021-02-16 04:38:52 发布 · 128 阅读

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#数据库 #java #测试

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一、iBATIS简介：

iBATIS一词来源于“internet”和“abatis”的组合，是一个由Clinton Begin在2001年发起的开放源代码项目。最初侧重于密码软件的开发，现在是一个基于Java的持久层框架ibatis本是apache的一个开源项目，2010年这个项目由apache software foundation 迁移到了google code，并且改名为mybatis。

二、建立Java Project

三、导jar包：ibatis-2.3.4.726.jar

四、entity，同时需要相关的实体类xml文件

1.Classes类

package org.e276.entity;

public class Classes {

	private Integer id; 
	private String name; 
	private String beginDate; 
	private String endDate;
	
	//构造方法

	public Classes() {
		super();
	}
	
	public Classes(Integer id) {
		super();
		this.id = id;
	}
	
	public Classes(Integer id, String name, String beginDate, String endDate) {
		super();
		this.id = id;
		this.name = name;
		this.beginDate = beginDate;
		this.endDate = endDate;
	}

	//getter/setter
	
	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 getBeginDate() {
		return beginDate;
	}

	public void setBeginDate(String beginDate) {
		this.beginDate = beginDate;
	}

	public String getEndDate() {
		return endDate;
	}

	public void setEndDate(String endDate) {
		this.endDate = endDate;
	}
	
}

2.Students类

package org.e276.entity;

public class Students {

	private Integer id;
	private String name;
	private Integer age;
	private Classes classes;

	// 构造方法

	public Students() {
		super();
	}

	public Students(String name, Integer age, Classes classes) {
		super();
		this.name = name;
		this.age = age;
		this.classes = classes;
	}

	// getter/setter

	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 Integer getAge() {
		return age;
	}

	public void setAge(Integer age) {
		this.age = age;
	}

	public Classes getClasses() {
		return classes;
	}

	public void setClasses(Classes classes) {
		this.classes = classes;
	}

	@Override
	public String toString() {
		return "Students [id=" + id + ", name=" + name + ", age=" + age + "]";
	}

}

3.Students.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sqlMap      
    PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN"      
    "sql-map-2.dtd">

<sqlMap namespace="me">

	<typeAlias alias="Students" type="org.e276.entity.Students" />
	<typeAlias alias="Classes" type="org.e276.entity.Classes" />

	<!-- 学生类，多对一，如果列名和属性名完全一样，则不用映射 -->
	<resultMap class="Students" id="StudentsResult">
		<result property="id" column="id" />
		<result property="name" column="name" />
		<result property="age" column="age" />
		<result property="classes" column="class_id" select="getClassesById" />
	</resultMap>

	<!-- 班级类 -->
	<resultMap class="Classes" id="ClassesResult">
		<result property="id" column="id" />
		<result property="name" column="name" />
		<result property="beginDate" column="begin_date" />
		<result property="endDate" column="end_date" />
	</resultMap>

	<!-- 如果名不同，则必须加上as，通过id查找班级 -->
	<select id="getClassesById" parameterClass="int" resultMap="ClassesResult">
		select * from classes where id = #value#
	</select>

	<!-- 查找所有的学生 -->
	<select id="getAllStudents" resultMap="StudentsResult">
		select * from students
	</select>

	<!-- 根据id得到当前班级所有的学生 -->
	<select id="getStudentsByClassId" resultClass="Students"
		parameterClass="int">
		<![CDATA[
			select id, name, age, class_id from students where class_id = #value#
		]]>
	</select>

	<!-- 插入学生 -->
	<insert id="saveStudent" parameterClass="Students">
		<!-- 注意Oracle中的id是以序列的形式插入，不能省略id这一列 -->
		<![CDATA[
			insert into students values(students_seq.nextval,#name#, #age#, #classes.id#)
		]]>
		<!-- 返回主键 -->
		<selectKey resultClass="int" keyProperty="id">
			<!-- Oracle中的写法：select 序列名.currval as id from dual -->
			<![CDATA[
				select students_seq.currval as id from dual
			]]>
		</selectKey>
	</insert>

	<!-- 多表联接查询,查询学生表和班级表 -->
	<select id="selectStudentsAndClasses" resultClass="java.util.HashMap">
		<![CDATA[
			select s.id as sid, s.name as sname, s.age as sage, c.name as cname from students s inner join classes c on s.class_id = c.id 
		]]>
	</select>
</sqlMap>

五、测试类（使用单元测试）

package org.e276.test;

import java.io.Reader;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
import org.e276.entity.Classes;
import org.e276.entity.Students;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.ibatis.common.resources.Resources;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;

public class TestStudents {

	SqlMapClient sqlMapper;

	@Before
	public void setUp() throws Exception {
		Reader reader = Resources.getResourceAsReader("SqlMapConfig.xml");
		// 得到SqlMapClient接口对象
		sqlMapper = SqlMapClientBuilder.buildSqlMapClient(reader);
		// 关闭对象
		reader.close();
	}

	@After
	public void tearDown() throws Exception {
		sqlMapper = null;
	}

	/**
	 * 通过id查找班级
	 * 
	 * @throws SQLException
	 */
	public void getClassesById() throws SQLException {
		@SuppressWarnings("unchecked")
		List<Classes> classes = sqlMapper.queryForList("getClassesById", 2);
		for (Classes clazz : classes) {
			System.out.println("班级名：" + clazz.getName());
		}
	}

	/**
	 * 查找所有的学生
	 * 
	 * @throws SQLException
	 */
	
	public void getAllStudents() throws SQLException {
		@SuppressWarnings("unchecked")
		List<Students> students = sqlMapper.queryForList("getAllStudents");
		for (Students stus : students) {
			System.out.println(stus);
		}
	}

	/**
	 * 查询班级ID为3的学生信息
	 * 
	 * @throws SQLException
	 */
	
	public void getStudentsByClassId() throws SQLException {
		@SuppressWarnings("unchecked")
		List<Students> stuList = sqlMapper.queryForList("getStudentsByClassId", 3);
		for (Students students : stuList) {
			System.out.println(students);
		}
	}

	/**
	 * 插入一个学生记录
	 * 
	 * @throws SQLException
	 */
	
	public void saveStudent() throws SQLException {
		Students student = new Students("李某某", 32, new Classes(2));
		int id = (Integer) sqlMapper.insert("saveStudent", student);
		System.out.println(id);
	}

	/**
	 * 多表联接，查询学生表和班级表
	 * 
	 * @throws SQLException
	 */
	@Test
	public void selectStudentsAndClasses() throws SQLException {
		@SuppressWarnings("unchecked")
		List<Map<String, Object>> result = sqlMapper.queryForList("selectStudentsAndClasses");
		for (Map<String, Object> map : result) {
			System.out.println("序号：" + map.get("SID"));
			System.out.println("学生姓名：" + map.get("SNAME"));
			System.out.println("年龄：" + map.get("SAGE"));
			System.out.println("班级名：" + map.get("CNAME"));
			System.out.println("-------------");
		}
	}
}

六、iBatis的配置文件 SqlMapConfig.xml

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE sqlMapConfig      
    PUBLIC "-//ibatis.apache.org//DTD SQL Map Config 2.0//EN"      
    "http://ibatis.apache.org/dtd/sql-map-config-2.dtd">

<sqlMapConfig>

  <!-- Configure a built-in transaction manager.  If you're using an 
       app server, you probably want to use its transaction manager 
       and a managed datasource -->
  <transactionManager type="JDBC" commitRequired="false">
    <dataSource type="SIMPLE">
      <property name="JDBC.Driver" value="oracle.jdbc.driver.OracleDriver"/>
      <property name="JDBC.ConnectionURL" value="jdbc:oracle:thin:@localhost:1521:orcl"/>
      <property name="JDBC.Username" value="y2"/>
      <property name="JDBC.Password" value="bdqn"/>
    </dataSource>
  </transactionManager>

  <!-- List the SQL Map XML files. They can be loaded from the 
       classpath, as they are here (com.domain.data...) -->
  <sqlMap resource="org/e276/entity/Students.xml"/>
  <!-- List more here...
  <sqlMap resource="com/mydomain/data/Order.xml"/>
  <sqlMap resource="com/mydomain/data/Documents.xml"/>
  -->

</sqlMapConfig>

七、demo

E276-iBatis.zip