iBatis 简介:
iBatis 是apache 的一个开源项目,一个O/R Mapping 解决方案,iBatis 最大的特点就是小巧,上手很快。如果不需要太多复杂的功能,iBatis 是能够满足你的要求又足够灵活的最简单的解决方案,现在的iBatis 已经改名为Mybatis 了。
官网为:http://www.mybatis.org/
搭建iBatis 开发环境:
1 、导入相关的jar 包,ibatis-2.3.0.677.jar 、mysql-connector-java-5.1.6-bin.jar
2 、编写配置文件:
Jdbc 连接的属性文件
总配置文件, SqlMapConfig.xml
关于每个实体的映射文件(Map 文件)
Demo :
Student.java:
- package com.iflytek.entity;
- import java.sql.Date;
- /**
- * @author xudongwang 2011-12-31
- *
- * Email:xdwangiflytek@gmail.com
- *
- */
- public class Student {
- // 注意这里需要保证有一个无参构造方法,因为包括Hibernate在内的映射都是使用反射的,如果没有无参构造可能会出现问题
- private int id;
- private String name;
- private Date birth;
- private float score;
- 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 Date getBirth() {
- return birth;
- }
- public void setBirth(Date birth) {
- this.birth = birth;
- }
- public float getScore() {
- return score;
- }
- public void setScore(float score) {
- this.score = score;
- }
- @Override
- public String toString() {
- return "id=" + id + "\tname=" + name + "\tmajor=" + birth + "\tscore="
- + score + "\n";
- }
- }
SqlMap.properties :
- driver=com.mysql.jdbc.Driver
- url=jdbc:mysql://localhost:3306/ibatis
- username=root
- password=123
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.iflytek.entity.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="selectAllStudent" resultClass="Student">
- select * from
- tbl_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="selectStudentById" parameterClass="int" resultClass="Student">
- select * from tbl_student where id=#id#
- </select>
- <!-- 注意这里的resultClass类型,使用Student类型取决于queryForList还是queryForObject -->
- <select id="selectStudentByName" parameterClass="String"
- resultClass="Student">
- select name,birth,score from tbl_student where name like
- '%$name$%'
- </select>
- <insert id="addStudent" parameterClass="Student">
- insert into
- tbl_student(name,birth,score) values
- (#name#,#birth#,#score#);
- <selectKey resultClass="int" keyProperty="id">
- select @@identity as inserted
- <!-- 这里需要说明一下不同的数据库主键的生成,对各自的数据库有不同的方式: -->
- <!-- mysql:SELECT LAST_INSERT_ID() AS VALUE -->
- <!-- mssql:select @@IDENTITY as value -->
- <!-- oracle:SELECT STOCKIDSEQUENCE.NEXTVAL AS VALUE FROM DUAL -->
- <!-- 还有一点需要注意的是不同的数据库生产商生成主键的方式不一样,有些是预先生成 (pre-generate)主键的,如Oracle和PostgreSQL。
- 有些是事后生成(post-generate)主键的,如MySQL和SQL Server 所以如果是Oracle数据库,则需要将selectKey写在insert之前 -->
- </selectKey>
- </insert>
- <delete id="deleteStudentById" parameterClass="int">
- <!-- #id#里的id可以随意取,但是上面的insert则会有影响,因为上面的name会从Student里的属性里去查找 -->
- <!-- 我们也可以这样理解,如果有#占位符,则ibatis会调用parameterClass里的属性去赋值 -->
- delete from tbl_student where id=#id#
- </delete>
- <update id="updateStudent" parameterClass="Student">
- update tbl_student set
- name=#name#,birth=#birth#,score=#score# where id=#id#
- </update>
- </sqlMap>
说明:
如果xml 中没有ibatis 的提示,则window --> Preference--> XML-->XML Catalog---> 点击add
选择uri URI: 请选择本地文件系统上
iBatisDemo1/WebContent/WEB-INF/lib/sql-map-config-2.dtd 文件;
Key Type: 选择Schema Location;
Key: 需要联网的,不建议使用;
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/iflytek/entity/SqlMap.properties" />
- <!-- 使用JDBC的事务管理 -->
- <transactionManager type="JDBC">
- <!-- 数据源 -->
- <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>
- <!-- 这里可以写多个实体的映射文件 -->
- <sqlMap resource="com/iflytek/entity/Student.xml" />
- </sqlMapConfig>
StudentDao :
- package com.iflytek.dao;
- import java.util.List;
- import com.iflytek.entity.Student;
- /**
- * @author xudongwang 2011-12-31
- *
- * Email:xdwangiflytek@gmail.com
- *
- */
- public interface StudentDao {
- /**
- * 添加学生信息
- *
- * @param student
- * 学生实体
- * @return 返回是否添加成功
- */
- public boolean addStudent(Student student);
- /**
- * 根据学生id删除学生信息
- *
- * @param id
- * 学生id
- * @return 删除是否成功
- */
- public boolean deleteStudentById(int id);
- /**
- * 更新学生信息
- *
- * @param student
- * 学生实体
- * @return 更新是否成功
- */
- public boolean updateStudent(Student student);
- /**
- * 查询全部学生信息
- *
- * @return 返回学生列表
- */
- public List<Student> selectAllStudent();
- /**
- * 根据学生姓名模糊查询学生信息
- *
- * @param name
- * 学生姓名
- * @return 学生信息列表
- */
- public List<Student> selectStudentByName(String name);
- /**
- * 根据学生id查询学生信息
- *
- * @param id
- * 学生id
- * @return 学生对象
- */
- public Student selectStudentById(int id);
- }
StudentDaoImpl :
- package com.iflytek.daoimpl;
- import java.io.IOException;
- import java.io.Reader;
- import java.sql.SQLException;
- import java.util.List;
- import com.ibatis.common.resources.Resources;
- import com.ibatis.sqlmap.client.SqlMapClient;
- import com.ibatis.sqlmap.client.SqlMapClientBuilder;
- import com.iflytek.dao.StudentDao;
- import com.iflytek.entity.Student;
- /**
- * @author xudongwang 2011-12-31
- *
- * Email:xdwangiflytek@gmail.com
- *
- */
- public class StudentDaoImpl implements StudentDao {
- private static SqlMapClient sqlMapClient = null;
- // 读取配置文件
- static {
- try {
- Reader reader = Resources
- .getResourceAsReader("com/iflytek/entity/SqlMapConfig.xml");
- sqlMapClient = SqlMapClientBuilder.buildSqlMapClient(reader);
- reader.close();
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- public boolean addStudent(Student student) {
- Object object = null;
- boolean flag = false;
- try {
- object = sqlMapClient.insert("addStudent", student);
- System.out.println("添加学生信息的返回值:" + object);
- } catch (SQLException e) {
- e.printStackTrace();
- }
- if (object != null) {
- flag = true;
- }
- return flag;
- }
- public boolean deleteStudentById(int id) {
- boolean flag = false;
- Object object = null;
- try {
- object = sqlMapClient.delete("deleteStudentById", id);
- System.out.println("删除学生信息的返回值:" + object + ",这里返回的是影响的行数");
- } catch (SQLException e) {
- e.printStackTrace();
- }
- if (object != null) {
- flag = true;
- }
- return flag;
- }
- public boolean updateStudent(Student student) {
- boolean flag = false;
- Object object = false;
- try {
- object = sqlMapClient.update("updateStudent", student);
- System.out.println("更新学生信息的返回值:" + object + ",返回影响的行数");
- } catch (SQLException e) {
- e.printStackTrace();
- }
- if (object != null) {
- flag = true;
- }
- return flag;
- }
- public List<Student> selectAllStudent() {
- List<Student> students = null;
- try {
- students = sqlMapClient.queryForList("selectAllStudent");
- } catch (SQLException e) {
- e.printStackTrace();
- }
- return students;
- }
- public List<Student> selectStudentByName(String name) {
- List<Student> students = null;
- try {
- students = sqlMapClient.queryForList("selectStudentByName",name);
- } catch (SQLException e) {
- e.printStackTrace();
- }
- return students;
- }
- public Student selectStudentById(int id) {
- Student student = null;
- try {
- student = (Student) sqlMapClient.queryForObject(
- "selectStudentById", id);
- } catch (SQLException e) {
- e.printStackTrace();
- }
- return student;
- }
- }
TestIbatis.java :
- package com.iflytek.test;
- import java.sql.Date;
- import java.util.List;
- import com.iflytek.daoimpl.StudentDaoImpl;
- import com.iflytek.entity.Student;
- /**
- * @author xudongwang 2011-12-31
- *
- * Email:xdwangiflytek@gmail.com
- *
- */
- public class TestIbatis {
- public static void main(String[] args) {
- StudentDaoImpl studentDaoImpl = new StudentDaoImpl();
- System.out.println("测试插入");
- Student addStudent = new Student();
- addStudent.setName("李四");
- addStudent.setBirth(Date.valueOf("2011-09-02"));
- addStudent.setScore(88);
- System.out.println(studentDaoImpl.addStudent(addStudent));
- System.out.println("测试根据id查询");
- System.out.println(studentDaoImpl.selectStudentById(1));
- System.out.println("测试模糊查询");
- List<Student> *Lists = studentDaoImpl.selectStudentByName("李");
- for (Student student : *Lists) {
- System.out.println(student);
- }
- System.out.println("测试查询所有");
- List<Student> students = studentDaoImpl.selectAllStudent();
- for (Student student : students) {
- System.out.println(student);
- }
- System.out.println("根据id删除学生信息");
- System.out.println(studentDaoImpl.deleteStudentById(1));
- System.out.println("测试更新学生信息");
- Student updateStudent = new Student();
- updateStudent.setId(1);
- updateStudent.setName("李四1");
- updateStudent.setBirth(Date.valueOf("2011-08-07"));
- updateStudent.setScore(21);
- System.out.println(studentDaoImpl.updateStudent(updateStudent));
- }
- }
iBatis 的优缺点:
优点:
1、 减少代码量,简单;
2、 性能增强;
3、 Sql 语句与程序代码分离;
4、 增强了移植性;
缺点:
1、 和Hibernate 相比,sql 需要自己写;
2、 参数数量只能有一个,多个参数时不太方便;