Spring_data_jpa以及Hibernate简单使用

Posted 2021-01-29 梓★鸿

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jdbcTemplate简介

　　Spring对数据库的操作在jdbc上面做了深层次的封装，使用spring的注入功能，可以把DataSource注册到JdbcTemplate之中。

　　JdbcTemplate位于中。其全限定命名为org.springframework.jdbc.core.JdbcTemplate。要使用JdbcTemlate还需一个这个包包含了一下事务和异常控制。

JdbcTemplate主要提供以下五类方法：

execute方法：可以用于执行任何SQL语句，一般用于执行DDL语句；
update方法及batchUpdate方法：update方法用于执行新增、修改、删除等语句；batchUpdate方法用于执行批处理相关语句；
query方法及queryForXXX方法：用于执行查询相关语句；
call方法：用于执行存储过程、函数相关语句。

首先在pom.xml添加依赖

<!-- https://mvnrepository.com/artifact/org.springframework.data/spring-data-jpa -->
  <!--MariaDB 数据库驱动  -->
          <dependency>
              <groupId>org.mariadb.jdbc</groupId>
              <artifactId>mariadb-java-client</artifactId>
              <version>2.3.0</version>
          </dependency>
  
         <!--c3p0 数据库连接池-->
         <dependency>
             <groupId>com.mchange</groupId>
             <artifactId>c3p0</artifactId>
             <version>0.9.5.2</version>
         </dependency>
 
            <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-jdbc</artifactId>
             <version>5.1.3.RELEASE</version>
        </dependency>

项目结构：

创建图书实体类：

package the_template_data_jpa;

public class Book {
    private int id;
    private String bookname;
    private float price;

    public Book(int id, String bookname, float price) {
        this.id = id;
        this.bookname = bookname;
        this.price = price;
    }

    public int getId() {
        return id;
    }

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

    public String getBookname() {
        return bookname;
    }

    public void setBookname(String bookname) {
        this.bookname = bookname;
    }

    public float getPrice() {
        return price;
    }

    public void setPrice(float price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Book{" +
                "id=" + id +
                ", bookname=\'" + bookname + \'\\\'\' +
                ", price=" + price +
                \'}\';
    }
}

创建BookDAO

package the_template_data_jpa;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcOperations;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.support.TransactionTemplate;

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

@Repository
public class BookDAO {
    @Autowired
    private JdbcOperations jdbcOperations;


    public List<Map<String, Object>> getToList() {
        List<Map<String, Object>> maps = jdbcOperations.queryForList("select * from book where id > 0");
        return maps;
    }

    public Map<String, Object> getToMap() {
        String sql = "select * from book where id > ?;";
        Map<String, Object> ret = jdbcOperations.queryForMap(sql,2);
        return ret;
    }

    public Book getToBook() {
        String sql = "select * from book where id > 2;";
        Book book = jdbcOperations.queryForObject(
                sql, (rs, rowNum) -> new Book(rs.getInt(1), rs.getString(2), rs.getFloat(3))
        );
        return book;
    }

    public void create(String bookname, int price) {
        String sql = " insert into book (bookname,price) values (?,?)";
        int javaWeb = jdbcOperations.update(sql, bookname, price);
        if (javaWeb > 0) {
            System.out.println("数据插入成功");
        }
    }


}

jdbcTemplate包各类代码

JDBCTemplateConfig 类

package the_template_data_jpa;


import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.jdbc.core.JdbcTemplate;

import javax.sql.DataSource;
import java.beans.PropertyVetoException;

@Configuration
public class JDBCTemplateConfig {

    @Bean
    DataSource dataSource (Environment env) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass(env.getProperty("jdbc.driver"));
        dataSource.setJdbcUrl(env.getProperty("jdbc.url"));
        dataSource.setUser(env.getProperty("jdbc.user"));
        dataSource.setPassword(env.getProperty("jdbc.password"));

        return dataSource;
    }

    @Bean
    JdbcTemplate jdbcTemplate (DataSource dataSource){
        return new JdbcTemplate(dataSource);
    }

}

配置：扫描

package the_template_data_jpa;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.PropertySource;

@Configuration //声明当前配置类
@ComponentScan(basePackages = "the_template_data_jpa") // 扫描当前包 使用 spring 注解
@PropertySource("classpath:application.properties")//加载 资源文件
@Import({JDBCTemplateConfig.class})//扫描 使用 jpa 注解的接口
public class SpringConfig {
}

jdbc.properties 资源文件：

jdbc.driver=org.mariadb.jdbc.Driver
jdbc.url=jdbc:mariadb://localhost:3306/stu
jdbc.user=root
jdbc.password=666666

测试：

package the_template_data_jpa;

        import org.springframework.context.annotation.AnnotationConfigApplicationContext;

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

public class Main {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext Ioc = new AnnotationConfigApplicationContext(SpringConfig.class);
        BookDAO bean = Ioc.getBean(BookDAO.class);
        List<Map<String, Object>> toList = bean.getToList();
        System.out.println(toList);
        
    }
}

结果：

源码地址:https://github.com/nongzihong/Spring_Data_jps_Hibernate

 1 package com.oukele.jdbcTemplate;
 2 
 3 import com.mchange.v2.c3p0.ComboPooledDataSource;
 4 import org.springframework.context.annotation.Bean;
 5 import org.springframework.context.annotation.ComponentScan;
 6 import org.springframework.context.annotation.Configuration;
 7 import org.springframework.context.annotation.PropertySource;
 8 import org.springframework.core.env.Environment;
 9 import org.springframework.jdbc.core.JdbcTemplate;
10 import org.springframework.jdbc.datasource.DataSourceTransactionManager;
11 import org.springframework.transaction.PlatformTransactionManager;
12 import org.springframework.transaction.support.TransactionTemplate;
13 
14 import javax.sql.DataSource;
15 import java.beans.PropertyVetoException;
16 
17 @Configuration
18 @PropertySource(value = "classpath:jdbc.properties")//加载资源
19 @ComponentScan(basePackages = "com.oukele.jdbcTemplate")//扫描 spring 注解
20 public class JDBCTemplateConfig {
21 
22     //数据源
23     @Bean
24     DataSource dataSource(Environment env) throws PropertyVetoException {
25         ComboPooledDataSource dataSource = new ComboPooledDataSource();
26         dataSource.setDriverClass(env.getProperty("jdbc.driver"));
27         dataSource.setJdbcUrl(env.getProperty("jdbc.url"));
28         dataSource.setUser(env.getProperty("jdbc.user"));
29         dataSource.setPassword(env.getProperty("jdbc.password"));
30         return dataSource;
31     }
32     //jdbc 模板
33     @Bean
34     JdbcTemplate jdbcTemplate (DataSource dataSource){
35         return new JdbcTemplate(dataSource);
36     }
37     //事务管理器
38     @Bean
39     DataSourceTransactionManager transactionManager(DataSource dataSource){//事务管理
40         return new DataSourceTransactionManager(dataSource);
41     }
42     //事务模板
43     @Bean
44     TransactionTemplate transactionTemplate(PlatformTransactionManager platformTransactionManager){
45         return new TransactionTemplate(platformTransactionManager);
46     }
47 
48 
49 
50 
51 
52 }

UserDao类

package com.oukele.jdbcTemplate;

import com.oukele.entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcOperations;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.support.TransactionTemplate;

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

@Repository
public class UserDao {

    @Autowired
    private JdbcOperations jdbcOperations;
    @Autowired
    private TransactionTemplate transactionTemplate;

　　
    public List<Map<String, Object>> getToList () {
        List<Map<String, Object>> maps = jdbcOperations.queryForList("select * from user");
        return maps;
    }

    public Map<String, Object> getToMap () {
        String sql = "select * from user where userName = ?";

        Map<String, Object> ret = jdbcOperations.queryForMap(sql, "oukele1");
        return ret;
    }

    public User getToUser () {
        String sql = "select * from user where userName = \'oukele\'";

        User user = jdbcOperations.queryForObject(
                sql,
                (rs, rowNum) -> new User(rs.getString(1),rs.getString(2))
        );
        return user;
    }

    public int create(String userName, String password) {

        transactionTemplate.execute(status ->{
            String sql = "insert into user (userName, password) values (?, ?)";
            String sq2 = "insert into user (userName, passord) values (?, ?)";
            jdbcOperations.update(sq2,userName,password);
            return jdbcOperations.update(sql, userName, password);
        });
        return 0;
    }
}

Main类 (测试类)

 1 package com.oukele.jdbcTemplate;
 2 
 3 import com.oukele.entity.User;
 4 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 5 
 6 public class Main {
 7     public static void main(String[] args) {
 8         AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(JDBCTemplateConfig.class);
 9         UserDao dao = context.getBean(UserDao.class);
10 
11         System.out.println("------------------------- List -------------------------");
12         System.out.println(dao.getToList());
13         System.out.println("-------------------------键值对应-------------------------");
14         System.out.println(dao.getToMap());
15         System.out.println();
16         User user = dao.getToUser();
17         System.out.println(user);
18         System.out.println("-------------------------添加-------------------------");
19         System.out.println(dao.create("JAVA", "123"));
20 
21     }
22 }

jdbc.properties 资源文件

1 jdbc.driver=org.mariadb.jdbc.Driver
2 jdbc.url=jdbc:mariadb://localhost:3306/test
3 jdbc.user=oukele
4 jdbc.password=oukele

测试结果：

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