ibatis入门

   一：ibatis简介 ibatis是apache的一个开源的框架，实现了O/R mapping(对象关系映射)。特点：小巧上手比较快。
     优点：
          1):java代码和sql语句分离，这样在修改sql语句后，无须重新编译java代码
          2):ibatis对jdbc进行了封装，使用者无须手动写代码把数据放到对象中
          3):简单容易上手
     缺点：
          1):相对于hibernate来说，ibatis需要手动写sql语句。
          2):ibatis在给sql语句传递参数时，只能传递一个参数。
     二：ibatis简单使用
       
        步骤： 1):导入相关jar包：ibatis-xxx.jar,mysql-connector-java- xxx-bin.jar(附件中可以下载)
              2):总配置文件(SqlMapConfig.xml)
              3):实体映射文件(对实体操作的sql语句映射)
    三：实例

    jdbc.properties文件

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/ibatis
username=root
password=123

 

 

    总配置SqlMapConfig.xml内容：

<?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> 
	<!-- 加载数据库连接信息配置文件 -->
	<properties resource="jdbc.properties" /> 
	<transactionManager type="JDBC"> 
		<dataSource type="SIMPLE"> 
			<property name="JDBC.Driver" value="${driver}" /> 
			<property name="JDBC.ConnectionURL" value="${url}" /> 
			<property name="JDBC.Username" value="${username}" /> 
			<property name="JDBC.Password" value="${password}" /> 
		</dataSource> 
	</transactionManager> 
        <!-- 引入实体映射文件 -->
	<sqlMap resource="com/zt/entity/Student.xml" /> 
</sqlMapConfig> 

     实体映射文件Student.xml:

   

<?xml version="1.0" encoding="UTF-8" ?> 
<!DOCTYPE sqlMap PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN" 
"http://ibatis.apache.org/dtd/sql-map-2.dtd"> 
<sqlMap> 
	<!-- alias 可以看成是Student的别名，这样在下面就不用写类的全限定名 了， 只写别名即可 -->
	<typeAlias alias="Student" type="com.zt.entity.Student" /> 
	<!-- 查询所有学生信息 -->
	<select id="queryAllStudents" resultClass="Student"> 
		select * from student 
	</select> 

	<!-- 通过参数查询学生信息 -->
 	<select id="getStudentById" parameterClass="int" resultClass="Student">
		select * from student where id=#id#    
		<!-- #id#  类似于占位符-->
 	</select> 
 	
	<!-- 根据参数进行模糊查询 -->
 	<select id="queryStudentsByName" parameterClass="String"
		resultClass="Student">  
 		select * from student where name like '%$name$%'
 	</select>  

	<!-- 插入操作 -->
	<insert id="insertStudent" parameterClass="Student">
		insert into student (id, name, birthday, password) 
		values
		(#id#, #name#, #birthday#, #password#) 
	</insert>
	
	<!-- 插入操作，主键自动生成 -->
	<insert id="insertStudent1" parameterClass="Student">
	   <selectKey resultClass="int" keyProperty="id">  
             SELECT @@IDENTITY AS ID 
           </selectKey>  
		insert into student (id, name, birthday, password) 
		values
		(#id#, #name#, #birthday#, #password#) 
		
	</insert>
	<!-- 更新操作 -->
 	<update id="updateStudent" parameterClass="Student">
 		update student set name=#name#,birthday=#birthday#,password=#password# where id=#id# 
	</update>  
	
	<!-- 删除操作 -->
	<delete id="deleteById" parameterClass="int"> 
		delete from student where id=#id#
	</delete>

</sqlMap> 

    实体Student.java

 

 

package com.zt.entity;

import java.util.Date;

public class Student {
	private int id;
	private String name;
	private String password;
	private Date birthday;
	
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public Date getBirthday() {
		return birthday;
	}
	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}
	
	@Override
	public String toString() {
		return "id:" + id + " name:" + name + "    password:" + password;
	}
}

    IStudent 接口，定义了对Student的常用操作

 

   

package com.zt.entity;

import java.util.List;

/**
 * 学生增删改
 * @author zt_pc
 *
 */
public interface IStudentDao {
	/**
	 * 添加操作
	 * @param student
	 * @return
	 */
	public Integer save(Student student);
	/**
	 * 添加操作主键自动生成
	 * @param student
	 * @return Integer
	 */
	public Integer save1(Student student);
	/**
	 * 更新操作
	 * @param student
	 * @return
	 */
	public void update(Student student);
	/**
	 * 查询所有学生信息
	 * @param student
	 * @return List<Student>
	 */
	public List<Student> queryStudents();
	/**
	 * 根据ID查询学生信息
	 * @param id
	 * @return Student
	 */
	public Student getStudentById(int id);
	/**
	 * 模糊查询
	 * @param name
	 * @return
	 */
	public List<Student> queryStudentsByName(String name);
	/**
	 * 删除操作
	 * @param id
	 * @return
	 */
	public void deleteById(int id);
}

    StudentDao 实现了ISudentDao

 

package com.zt.entity;

import java.io.IOException;
import java.io.Reader;
import java.sql.SQLException;
import java.util.Date;
import java.util.List;

import com.ibatis.common.resources.Resources;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;

public class StudentDao implements IStudentDao {

	private static SqlMapClient sqlMapClient = null;
	
	static {
		try {
			Reader reader = Resources.getResourceAsReader("SqlMapConfig.xml");
			sqlMapClient = SqlMapClientBuilder.buildSqlMapClient(reader);
		} catch (IOException e) {
			throw new RuntimeException("文件未找到");
		}
	}
	
	@Override
	public Integer save(Student student) {
		Integer id = null;
		try {
			//queryForList的第一个参数是student.xml文件sql语句的id，第二个参数是要插入的数据
			id = (Integer)sqlMapClient.insert("insertStudent", student);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return id;
	}

	@Override
	public Integer save1(Student student) {
		Integer id = null;
		try {
			//queryForList的第一个参数是student.xml文件sql语句的id，第二个参数是要插入的数据
			id = (Integer)sqlMapClient.insert("insertStudent1", student);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return id;
	}

	@Override
	public void update(Student student) {
		try {
			//update的第一个参数是student.xml文件sql语句的id,第二个参数要更新数据
			sqlMapClient.update("updateStudent", student);
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	@SuppressWarnings("unchecked")
	@Override
	public List<Student> queryStudents() {
		List<Student> students = null;
		try {
			//queryForList的第一个参数是student.xml文件sql语句的id
			students = (List<Student>)sqlMapClient.queryForList("queryAllStudents");
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return students;
	}

	@SuppressWarnings("unchecked")
	@Override
	public List<Student> queryStudentsByName(String name) {
		List<Student> students = null;
		try {
			//queryForList的第一个参数是student.xml文件sql语句的id，第二个参数是查询条件
			students = sqlMapClient.queryForList("queryStudentsByName", name);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return students;
	}

	@Override
	public void deleteById(int id) {
		try {
			sqlMapClient.delete("deleteById", id);
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
	
	@Override
	public Student getStudentById(int id) {
		Student student= null;
		try {
			//queryForObject的第一个参数是student.xml文件sql语句的id，第二个参数是查询条件
			student = (Student) sqlMapClient.queryForObject("getStudentById", id);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return student;
	}
	
	//测试
	public static void main(String[] args) {
		IStudentDao studentDao = new StudentDao();
		
		//测试查询所有学生
		List<Student> students1 = studentDao.queryStudents();
		
		if(students1 == null) return;
		for (Student student : students1) {
			System.out.println(student);
		}
		
		
		//测试根据参数查询查询学生
		Student student1 = studentDao.getStudentById(1);
		if(student1 == null) return;
		System.out.println(student1);
		
		//测试模糊查询
		List<Student> students2 = studentDao.queryStudentsByName("gs");
		if(students2 == null) return;
		for (Student student : students2) {
			System.out.println(student);
		}
		
		
//		测试插入操作
		Student student2 = new Student();
		student2.setId(4);
		student2.setName("wangsi");
		student2.setBirthday(new Date());
		student2.setPassword("123");
		
		Integer id = studentDao.save1(student2);
		System.out.println(id);
		
		
		//测试更新操作
		Student student3 = new Student();
		student3.setId(4);
		student3.setName("wangsi12");
		student3.setBirthday(new Date());
		student3.setPassword("1234");
		
		studentDao.update(student3);
		
		//测试删除操作
		studentDao.deleteById(6);
		
	}
}

 

 

   总结：ibatis在执行增删改查操作时，首先根据要执行sql语句的ID 去 实体映射文件中查找相应的sql语句。

其中parameterClass 属性表示传递参数的类型，returnClass 表示返回值的类型。