小峰mybatis（5）mybatis使用注解配置sql映射器--动态sql

一、使用注解配置映射器 动态sql：　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

用的并不是很多，了解下；

Student.java 实体bean：

package com.cy.model;

public class Student{
    private Integer id;
    private String name;
    private Integer age;

    public Student(){

    }

    public Student(String name, Integer age){
        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 + "]";
    }

}

com.cy.mapper下：

StudentDynaSqlProvider.java:

StudentMapper.java:

package com.cy.mapper;

import java.util.Map;

import org.apache.ibatis.jdbc.SQL;

import com.cy.model.Student;

public class StudentDynaSqlProvider {

    public String inertStudent(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();
    }
}

StudentMapper.java:

public interface StudentMapper {

    //插入
    @InsertProvider(type=StudentDynaSqlProvider.class,method="inertStudent")
    public int inertStudent(Student student);

    //更新
    @UpdateProvider(type=StudentDynaSqlProvider.class,method="updateStudent")
    public int updateStudent(Student stu);

    //删除
    @DeleteProvider(type=StudentDynaSqlProvider.class,method="deleteStudent")
    public int deleteStudent(int id);

    //根据id查找学生
    @SelectProvider(type=StudentDynaSqlProvider.class,method="getStudentById")
    public Student getStudentById(Integer id);

    //查询所有学生
    @SelectProvider(type=StudentDynaSqlProvider.class,method="findStudents")
    public List<Student> findStudents(Map<String,Object> map);

}

测试代码：

StudentTest.java:

 public class StudentTest {
     private static Logger logger = Logger.getLogger(StudentTest.class);

     private SqlSession sqlSession=null;
     private StudentMapper studentMapper=null;

     @Before
     public void setUp() throws Exception {
         sqlSession=SqlSessionFactoryUtil.openSession();
         studentMapper=sqlSession.getMapper(StudentMapper.class);
     }

     @After
     public void tearDown() throws Exception {
         sqlSession.close();
     }

     @Test
     public void testInsertStudent() {
         logger.info("测试insertStudent");
         Student stu = new Student("琪琪", 12);
         int count = studentMapper.inertStudent(stu);
         sqlSession.commit();
     }

     @Test
     public void testUpdateStudent() {
         logger.info("测试updateStudent");
         Student stu = new Student("琪琪琪琪", 13);
         stu.setId(16);
         int count = studentMapper.updateStudent(stu);
         sqlSession.commit();
     }

     @Test
     public void testDeleteStudent() {
         logger.info("测试删除学生");
         int count = studentMapper.deleteStudent(16);
         sqlSession.commit();
     }

     @Test
     public void testGetStudentById() {
         logger.info("根据id查找学生");
         Student student = studentMapper.getStudentById(1);
         System.out.println(student);
     }

     @Test
     public void testFindStudents() {
         logger.info("根据条件查找学生");
         Map<String,Object> map = new HashMap<String,Object>();
 //        map.put("name", "%a%");
         map.put("age", 14);
         List<Student> students = studentMapper.findStudents(map);
         for(Student student: students){
             System.out.println(student);
         }
     }
 }