ibatis框架搭建

标签：ibatis   数据库   持久层   orm   java   

最近项目中用到IBATIS ，我没有用过，现在开始慢慢学习。IBATIS是一个持久层框架，但是比HIBERNATE要轻许多，用ibatis基本上sql语句要自己写。今天下午做了一个简单的demo。

流程：在DAO中读取SqlMapConfig.xml文件（连接数据库，寻找实体类配置文件路径）。当DAO中调用sql语句时候：sqlMapClient.queryForList("getAllStudent"); 会去实体类的配置文件里面寻找sql语句。

1.下载ibatis Jar包，我用的是ibatis-2.3.0.677.jar

2.添加iBatis的config配置文件

com.lubby.bean.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>
	<!-- 引用JDBC属性的配置文件 -->
	<!-- <properties resource="com/lubby/bean/SqlMap.properties" /> -->
	<!-- 使用JDBC的事务管理 -->
	<transactionManager type="JDBC">
		<!-- 数据源 -->
		<dataSource type="SIMPLE">
			<property name="JDBC.Driver" value="org.postgresql.Driver" />
			<property name="JDBC.ConnectionURL" value="jdbc:postgresql://127.0.0.1:5432/lubby" />
			<property name="JDBC.Username" value="admin" />
			<property name="JDBC.Password" value="admin" />
		</dataSource>
	</transactionManager>
	<!-- 这里可以写多个实体的映射文件 -->
	<sqlMap resource="com/lubby/bean/Student.xml" />
</sqlMapConfig>

3.添加实体类

com.lubby.bean.Student.java

public class Student {
	private String sid;
	private String name;
	private int age;

	public Student() {
		super();
	}
	public Student(String sid, String name, int age) {
		super();
		this.sid = sid;
		this.name = name;
		this.age = age;
	}
	public String getSid() {
		return sid;
	}
	public void setSid(String sid) {
		this.sid = sid;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	@Override
	public String toString() {
		return "Student [sid=" + sid + ", name=" + name + ", age=" + age + "]";
	}
}

4.添加实体类的Maping文件

com.lubby.bean.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>
	<!-- 通过typeAlias使得我们在下面使用Student实体类的时候不需要写包名 -->
	<typeAlias alias="Student" type="com.lubby.bean.Student" />

	<!-- 这样以后改了sql，就不需要去改java代码了 -->
	<!-- id表示select里的sql语句，resultClass表示返回结果的类型 -->
	<select id="getAllStudent" resultClass="Student">
		select * from student
	</select>

	<!-- parameterClass表示参数的内容 -->
	<!-- #表示这是一个外部调用的需要传进的参数，可以理解为占位符 -->
	<select id="getStudentById" parameterClass="String" resultClass="Student">
		select * from student where sid=#id#
	</select>

</sqlMap>

5.DAO以及实现DAO

com.lubby.dao.StudentDAO.java

public interface StudentDAO {
	/**
	 * 获取所有学生
	 * @return 所有学生信息列表
	 */
	public List<Student> getAllStudent();
	/**
	 * 根据学生ID查询信息
	 * @return 所查学生信息
	 */
	public Student getStudentById(String id);

}

package com.lubby.daoimpl;

import java.io.IOException;
import java.io.Reader;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import com.ibatis.common.resources.Resources;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;
import com.lubby.bean.Student;
import com.lubby.dao.StudentDAO;

public class StudentDAOImpl implements StudentDAO {
	private static SqlMapClient sqlMapClient = null;

	// 读取配置文件
	static {
		try {
			Reader reader = Resources.getResourceAsReader("com/lubby/bean/SqlMapConfig.xml");
			sqlMapClient = SqlMapClientBuilder.buildSqlMapClient(reader);
			reader.close();
		} catch (IOException e) { 
			e.printStackTrace();
		}

	}

	@Override
	public List<Student> getAllStudent() {
		List<Student> list = null;
		try {
			list = sqlMapClient.queryForList("getAllStudent");
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return list;
	}

	@Override
	public Student getStudentById(String id) {
		Student student = null;
		try {
			student = (Student) sqlMapClient.queryForObject("getStudentById", id);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return student;
	}

}

6.调用DAO查询

com.lubby.test.IbatisTest.java

public class IbatisTest {
	public static void main(String[] args) {
		StudentDAO stuDaoImpl = new StudentDAOImpl();
		List<Student> list = new ArrayList<>();

		list = stuDaoImpl.getAllStudent();
		for (Student stu : list) {
			System.out.println(stu);
		}

		Student student = stuDaoImpl.getStudentById("003");
		System.out.println("ID为004的学生信息：" + student);
	}
}

7.结果显示

Student [sid=001, name=Tom, age=22]
Student [sid=002, name=Jack, age=23]
Student [sid=003, name=Tom, age=20]
Student [sid=004, name=Alice, age=18]
ID为004的学生信息：Student [sid=003, name=Tom, age=20]

ibatis框架搭建,布布扣,bubuko.com

ibatis框架搭建

标签：ibatis   数据库   持久层   orm   java   

原文地址：http://blog.csdn.net/liu00614/article/details/28650369