第十三节——JdbcTemplate使用

Posted 2021-10-24 想学习安全的小白

一、开发步骤

1. 导入spring-jdbc和spring-tx坐标
2. 创建数据库表和实体
3. 创建JdbcTemplate对象
4. 执行数据库操作

二、具体步骤

1. 导入坐标

<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>8.0.25</version>
</dependency>
<dependency>
  <groupId>com.alibaba</groupId>
  <artifactId>druid</artifactId>
  <version>1.2.7</version>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-jdbc</artifactId>
  <version>5.3.10</version>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-tx</artifactId>
  <version>5.3.10</version>
</dependency>

2. 在mysql中创建一个test数据库和student数据表，设置id和name两个字段
   
3. 创建一个student.class，设置两个属性id与name，设置getter和setter方法

@Controller
public class Student {
    private String name;
    private int age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\\'' +
                ", age=" + age +
                '}';
    }
}

4. 使用Junit测试JdbcTemplate的插入操作

@Test
public void test1(){
    //创建druid对象，设置数据源
    DruidDataSource dataSource = new DruidDataSource();
    dataSource.setDriverClassName("com.mysql.jdbc.Driver");
    dataSource.setUrl("jdbc:mysql://192.168.10.134:3306/test");
    dataSource.setUsername("root");
    dataSource.setPassword("970725");

    JdbcTemplate jdbcTemplate = new JdbcTemplate();
    jdbcTemplate.setDataSource(dataSource);
    //执行操作
    int row = jdbcTemplate.update("insert into student value (?,?)", 12, "qwe");
    System.out.println(row);
}

三、简化操作，将JDBCTemplate对象交由spring产生

1. 在resources目录下创建applicationContext文件

    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://192.168.10.134:3306/test"/>
        <property name="username" value="root"/>
        <property name="password" value="970725"/>
    </bean>
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>

2. 使用Junit测试插入操作

@Test
public void test1(){
    ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
    JdbcTemplate jdbcTemplate = (JdbcTemplate) app.getBean("jdbcTemplate");
    int row = jdbcTemplate.update("insert into student (id,name) values (?,?);", 13, "asd");
    System.out.println(row);
}

四、抽取JdbcTemplate类

五、使用JdbcTemplate进行查询操作

1. 查询全部

@Test
public void test1(){
    ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
    JdbcTemplate jdbcTemplate = (JdbcTemplate) app.getBean("jdbcTemplate");
    List<Student> students = jdbcTemplate.query("select * from student", new BeanPropertyRowMapper<Student>(Student.class));
    for (Student s:students){
        System.out.println(s);
    }
}

2. 查询单个

@Test
public void test1(){
    ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
    JdbcTemplate jdbcTemplate = (JdbcTemplate) app.getBean("jdbcTemplate");
    Student student = jdbcTemplate.queryForObject("select * from student where id=?", new BeanPropertyRowMapper<Student>(Student.class), 12);
    System.out.println(student);
}

3. 查询总数

@Test
public void test1(){
    ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
    JdbcTemplate jdbcTemplate = (JdbcTemplate) app.getBean("jdbcTemplate");
    Integer integer = jdbcTemplate.queryForObject("select count(*) from student", Integer.class);
    System.out.println(integer);
}