MyBatis 教程04

9. 使用注解的方式实现动态sql
<!-- \src\mybatis-config.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 resource="jdbc.properties"/>
    <typeAliases>
        <package name="com.java1234.model"/>
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driverClassName}" />
                <property name="url" value="${jdbc.url}" />
                <property name="username" value="${jdbc.username}" />
                <property name="password" value="${jdbc.password}" />
            </dataSource>
        </environment>
        <environment id="test">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driverClassName}" />
                <property name="url" value="${jdbc.url}" />
                <property name="username" value="${jdbc.username}" />
                <property name="password" value="${jdbc.password}" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <package name="com.java1234.mappers"/>
    </mappers>
</configuration>

# \src\jdbc.properties
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db_mybatis
jdbc.username=root
jdbc.password=123456

# \src\log4j.properties
log4j.rootLogger=info,appender1,appender2

log4j.appender.appender1=org.apache.log4j.ConsoleAppender 

log4j.appender.appender2=org.apache.log4j.FileAppender 
log4j.appender.appender2.File=C:/logFile.txt
 
log4j.appender.appender1.layout=org.apache.log4j.TTCCLayout
log4j.appender.appender2.layout=org.apache.log4j.TTCCLayout  

// \src\com\java1234\mappers\StudentDynaSqlProvider.java
package com.java1234.mappers;

import java.util.Map;

import org.apache.ibatis.jdbc.SQL;

import com.java1234.model.Student;

public class StudentDynaSqlProvider {

    public String insertStudent(final Student student){
        return new SQL(){
            {
                INSERT_INTO("t_student");
                if(student.getName()!=null){
                    VALUES("name", "#{name}");
                }
                if(student.getAge()!=null){
                    VALUES("age", "#{age}");
                }
            }
        }.toString();
    }
    
    public String updateStudent(final Student student){
        return new SQL(){
            {
                UPDATE("t_student");
                if(student.getName()!=null){
                    SET("name=#{name}");
                }
                if(student.getAge()!=null){
                    SET("age=#{age}");
                }
                WHERE("id=#{id}");
            }
        }.toString();
    }
    
    public String deleteStudent(){
        return new SQL(){
            {
                DELETE_FROM("t_student");
                WHERE("id=#{id}");
            }
        }.toString();
    }
    
    public String getStudentById(){
        return new SQL(){
            {
                SELECT("*");
                FROM("t_student");
                WHERE("id=#{id}");
            }
        }.toString();
    }
    
    public String findStudents(final Map<String,Object> map){
        return new SQL(){
            {
                SELECT("*");
                FROM("t_student");
                StringBuffer sb=new StringBuffer();
                if(map.get("name")!=null){
                    sb.append(" and name like '"+map.get("name")+"'");
                }
                if(map.get("age")!=null){
                    sb.append(" and age="+map.get("age"));
                }
                if(!sb.toString().equals("")){
                    WHERE(sb.toString().replaceFirst("and", ""));                    
                }
            }
        }.toString();
    }
}

// \src\com\java1234\mappers\StudentMapper.java
package com.java1234.mappers;

import java.util.List;
import java.util.Map;

import org.apache.ibatis.annotations.DeleteProvider;
import org.apache.ibatis.annotations.InsertProvider;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.SelectProvider;
import org.apache.ibatis.annotations.UpdateProvider;

import com.java1234.model.Student;


public interface StudentMapper {

    @InsertProvider(type=StudentDynaSqlProvider.class,method="insertStudent")
    public int insertStudent(Student student);
    
    @UpdateProvider(type=StudentDynaSqlProvider.class,method="updateStudent")
    public int updateStudent(Student student);
    
    @DeleteProvider(type=StudentDynaSqlProvider.class,method="deleteStudent")
    public int deleteStudent(int id);
    
    @SelectProvider(type=StudentDynaSqlProvider.class,method="getStudentById")
    public Student getStudentById(Integer id);
    
    @SelectProvider(type=StudentDynaSqlProvider.class,method="findStudents")
    public List<Student> findStudents(Map<String,Object> map);
    
}

// \src\com\java1234\model\Student.java
package com.java1234.model;

public class Student {

    private Integer id;
    private String name;
    private Integer age;

    
    
    public Student() {
        super();
        // TODO Auto-generated constructor stub
    }
    
    
    
    
    public Student(Integer id, String name, Integer age) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
    }




    public Student(String name, Integer age) {
        super();
        this.name = name;
        this.age = age;
    }



    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;
    }




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

    
    
}

// \src\com\java1234\service\StudentTest.java
package com.java1234.service;


import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.ibatis.session.SqlSession;
import org.apache.log4j.Logger;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.java1234.mappers.StudentMapper;
import com.java1234.model.Student;
import com.java1234.util.SqlSessionFactoryUtil;

public class StudentTest {

    private static Logger logger=Logger.getLogger(StudentTest.class);
    private SqlSession sqlSession=null;
    private StudentMapper studentMapper=null;
    
    /**
     * 测试方法前调用
     * @throws Exception
     */
    @Before
    public void setUp() throws Exception {
        sqlSession=SqlSessionFactoryUtil.openSession();
        studentMapper=sqlSession.getMapper(StudentMapper.class);
    }

    /**
     * 测试方法后调用
     * @throws Exception
     */
    @After
    public void tearDown() throws Exception {
        sqlSession.close();
    }

    @Test
    public void testInsert() {
        logger.info("添加学生");
        Student student=new Student("琪琪",11);
        studentMapper.insertStudent(student);
        sqlSession.commit();
    }
    
    @Test
    public void testUpdate() {
        logger.info("更新学生");
        Student student=new Student(6,"琪琪2",12);
        studentMapper.updateStudent(student);
        sqlSession.commit();
    }
    
    @Test
    public void testDelete() {
        logger.info("删除学生");
        studentMapper.deleteStudent(6);
        sqlSession.commit();
    }
    
    @Test
    public void testGetById() {
        logger.info("通过ID查找学生");
        Student student=studentMapper.getStudentById(1);
        System.out.println(student);
    }
    
    @Test
    public void testFindStudents() {
        logger.info("查找所有学生");
        Map<String,Object> map=new HashMap<String,Object>();
        // map.put("name", "%张%");
        // map.put("age", 12);
        List<Student> studentList=studentMapper.findStudents(map);
        for(Student student:studentList){
            System.out.println(student);
        }
    }

}

// \src\com\java1234\util\SqlSessionFactoryUtil.java
package com.java1234.util;

import java.io.InputStream;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class SqlSessionFactoryUtil {

    private static SqlSessionFactory sqlSessionFactory;
    
    public static SqlSessionFactory getSqlSessionFactory(){
        if(sqlSessionFactory==null){
            InputStream inputStream=null;
            try{
                inputStream=Resources.getResourceAsStream("mybatis-config.xml");
                sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);
            }catch(Exception e){
                e.printStackTrace();
            }
        }
        return sqlSessionFactory;
    }
    
    public static SqlSession openSession(){
        return getSqlSessionFactory().openSession();
    }
}