1、原始

Connection conn = null;String url = "jdbc:mysql://localhost:3306/emps?user=root&password=&useUnicode=true&characterEncoding=utf-8";try {    //加载驱动    Class.forName("com.mysql.jdbc.Driver");    conn = DriverManager.getConnection(url);    //conn=DriverManager.getConnection()    String sql = "select * from tm_project where proj_id=1";    PreparedStatement ps = conn.prepareStatement(sql);    ResultSet rs = ps.executeQuery("select * from tm_project where proj_id=2");    if (rs.next()) {        System.out.println(rs.getString("proj_name"));    }} catch (Exception e) {    e.printStackTrace();}

notice：1、没有rs.next不能使用rs.getXXX，报错（SQLException：Before start of result set）

2、mybatis only

①po、mapper.java、mapper.xml

②mybatis-mapper.xml

使用：String resource = "mybatis/mybatis-mapper.xml";InputStream is = demo02.class.getClassLoader().getResourceAsStream(resource);SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);SqlSession session = factory.openSession();String statement = "com.ytud.provider.mybatis.mapper.ProjectMapper.selectByPrimaryKey";int del = session.delete(statement);System.out.println(del);Project project = session.selectOne(statement, 2);System.out.println(project.getProjName());

3、mybatis+spring

applicationContext.xml

      
          
               
                    
        
         classpath:jdbc.properties
                 
            
       
     

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测试代码： //JUnitpublic class test1 {    private ProjectApiImpl projectApiImpl;    @Before    public void before() {        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");        projectApiImpl = (ProjectApiImpl) ac.getBean("projectApiImpl");    }    @Test    public void test1() {        ProjectModel project = projectApiImpl.getProject(1);        System.out.println(project.getProjectName());    }}//spring提供JUnit测试框架@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(locations = {"classpath:applicationContext.xml"})public class Demo02 {    @Resource    private ProjectApiImpl projectApiImpl;    @Test    public void test1() {        ProjectModel project = projectApiImpl.getProject(1);        System.out.println(project.getProjectName());    }}

 

4、mybatis+spring+spring mvc

web.xml
     
         
      
       org.springframework.web.context.ContextLoaderListener
      
     
     
         
      
       contextConfigLocation
          
      
       classpath:applicationContext.xml
      
     
     
         
      
       mvc-dispatcher
          
      
       org.springframework.web.servlet.DispatcherServlet
          
          
              
       
        contextConfigLocation
               
       
        classpath:mvc-servlet-config.xml
           
          
          
      
       1
      
     
         
      
       mvc-dispatcher
          
          
      
       /
      
     
     
         
      
       characterEncodingFilter
          
      
       org.springframework.web.filter.CharacterEncodingFilter
          
              
       
        encoding
               
       
        UTF-8
           
          
              
       
        forceEncoding
               
       
        true
           
      
     
         
      
       characterEncodingFilter
          
      
       /*
      
     

mvc-servlet-config.xml 
     
     
     
     
     
     
         
              
                   
                
           
      
     

5、mybatis+spring+spring mvc+dubbox