Spring-JdbcTemplate环境搭配及基本功能

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前言：当控制台报Unsupported class file major version 61错误时，建议更换JDK版本，换成JDK16以前的版本

父文章：Spring对数据持久化的支持

JdbcTemplate概述

Spring提供了工具类JdbcTemplate,该类对jdbc的操作进行了轻量级别的封装，包含了操作数据库的各种方法。该类包含一个dataSource属性（数据源），只有在初始化数据源的情况下才能调用JdbcTemplate的方法。

• 数据源：数据源为主流连接池的数据源对象（例如C3P0,DBCP数据库连接池），因此在使用JdbcTemplate前，要创建数据源对象。

• JdbcTemplate的优点：
  优点：运行期：高效、内嵌Spring框架中、支持基于AOP的声明式事务，可节省大量的冗余代码（创建连接，关闭连接，处理异常），只关注业务逻辑即可。

一、导入坐标

• 这边呢有用的没用的我都导了几个，之前有bug的时候加入的

<dependencies>
    <dependency>
      <groupId>junitgroupId>
      <artifactId>junitartifactId>
      <version>3.8.1version>
      <scope>testscope>
    dependency>
    <dependency>
      <groupId>com.alibabagroupId>
      <artifactId>druidartifactId>
      <version>1.1.17version>
    dependency>
    <dependency>
      <groupId>c3p0groupId>
      <artifactId>c3p0artifactId>
      <version>0.9.1.2version>
    dependency>
    <dependency>
      <groupId>mysqlgroupId>
      <artifactId>mysql-connector-javaartifactId>
      <version>8.0.28version>
    dependency>
    <dependency>
      <groupId>org.springframeworkgroupId>
      <artifactId>spring-contextartifactId>
      <version>5.2.10.RELEASEversion>
    dependency>

    <dependency>
      <groupId>org.springframeworkgroupId>
      <artifactId>spring-jdbcartifactId>
      <version>5.0.2.RELEASEversion>
    dependency>


  dependencies>
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二、在resource资源包下新建applicationContext.xml并配置

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">
    <context:property-placeholder location="jdbc.properties"/>
<context:component-scan base-package="com.wk">context:component-scan>


    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    bean>

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <constructor-arg index="0" ref="dataSource">constructor-arg>
    bean>
beans>
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在resource资源包下新建jdbc.properties存入MySQL的连接数据

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test
jdbc.username=root
jdbc.password=123
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三、建包测试一下

1、在pojo包下建User类

public class User {
  private String username;
  private String password;
  private String email;
  private String phone;
  private String birth;
  private Integer id;

    public User() {
    }

    public User(String username, String password, String email, String phone, String birth, Integer id) {
        this.username = username;
        this.password = password;
        this.email = email;
        this.phone = phone;
        this.birth = birth;
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getBirth() {
        return birth;
    }

    public void setBirth(String birth) {
        this.birth = birth;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    @Override
    public String toString() {
        return "User{" +
                "username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", email='" + email + '\'' +
                ", phone='" + phone + '\'' +
                ", birth='" + birth + '\'' +
                ", id=" + id +
                '}';
    }
}

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2、在UserDao接口下定义增删改查方法

public interface UserDao {
    //插入一条用户信息
    void adduser(User user);
    //查找用户信息
    List<User> queryuser(String username);
    //修改用户信息
    int  updateuser(String username,int id);
    //删除用户
    int  deleteuser(String username);

}
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3、在UserDaoImpl中实现Dao接口中的方法

public class UserDaoImpl implements UserDao {
        @Autowired
        private JdbcTemplate jdbcTemplate;

        @Override
        public void adduser(User user) {
                String sql="insert into user(username,password) value(?,?)";
                int update = jdbcTemplate.update(sql, user.getUsername(), user.getPassword());
                System.out.println(update);

        }

        @Override
        public List<User> queryuser(String username) {

                String sql = "select * from user where username=?";
				//创建一个新的BeanPropertyRowMapper对象
                RowMapper<User> rowMapper = new BeanPropertyRowMapper<User>(User.class);
				//将id绑定到SQL语句中，并通过RowMapper返回一个Object类型的单行记录
                List<User> query = jdbcTemplate.query(sql, rowMapper, username);
                return query;
        }

        @Override
        public int  updateuser(String username,int id) {
                String sql="update  user set username=? where id=?";
                int update = jdbcTemplate.update(sql, username,id);
                return update;
        }

        @Override
        public int  deleteuser(String username) {
                String sql = "delete from user where username=?";
                int update = jdbcTemplate.update(sql, username);
                return update;
        }
}
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4、编写测试类

public class Test {
    public static void main(String[] args) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserDao userDao= (UserDao) ctx.getBean("userDaoImpl");
        User user = new User();

        user.setUsername("北条");
        user.setPassword("123123");
        userDao.adduser(user);

//        List queryuser = userDao.queryuser("史蒂夫");
//        System.out.println(queryuser);

//        int ikun = userDao.updateuser("ikun", 2);
//        if (ikun==0){
//            System.out.println("信息修改失败");
//        }else {
//            System.out.println("修改成功");
//        }
//
//        int kun = userDao.deleteuser("小黑子");
//        if (kun==0){
//            System.out.println("删除失败");
//        }else {
//            System.out.println("删除成功");
//        }

    }
}

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