Spring Boot实现简单的增删改查-木庄网络博客

本文整理自网络，侵删。

在pom.xml添加相应的依赖

<dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <scope>runtime</scope>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
      <exclusions>
        <exclusion>
          <groupId>org.junit.vintage</groupId>
          <artifactId>junit-vintage-engine</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>2.1.3</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!-- 前端使用thymeleaf来代替jsp -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>
  </dependencies>

配置文件配置数据库等

#server
  server.port=80
  #项目名：server.servlet.context-path
  #spring dataSource
  spring.datasource.url=jdbc:mysql:///dbgoods?serverTimezone=GMT%2B8&characterEncoding=utf8
  spring.datasource.username=root
  spring.datasource.password=root
  mybatis.mapper-locations=classpath:/mapper/*/*.xml
  #spring log
  logging.level.com.cy=debug
  #spring thymeleaf（假如没有配置也会默认配置，在默认配置中prefix默认值为classpath:/templates/,后缀默认为.html）
  #不用重启服务器，网页就能刷新
  spring.thymeleaf.cache=false 
  spring.thymeleaf.prefix=classpath:/templates/pages/
  spring.thymeleaf.suffix=.html

数据层添加相应注解实现sql语句（或者通过xml配置来实现）

数据层封装了商品信息，并提供get和set方法，为Goods类

1.查询所有数据

@Select("select * from tb_goods")
  List<Goods> findAll();

2.按照id删除数据

@Delete("delete from tb_goods where id=#{id}")
  int deleteById(Integer id);

3.修改数据

（1）修改数据首先要新建一个界面，按照id查找内容，并将查找到的内容显示到文本框内

@Select("select * from tb_goods where id=#{id}")
  Goods findById(Integer id);

（2）再添加查找的方法

@Update("update tb_goods set name=#{name},remark=# {remark},createdTime=now() where id=#{id}")
  int update(Goods goods);

4.新增数据

@Insert("insert into tb_goods(name,remark,createdTime) values (#{name},#{remark},now())")
  int add(Goods goods);

业务层提供对应接口方法和实现类

1.业务层接口

public interface GoodsService {
  List<Goods> findObject();
  int add(Goods goods);
  int update(Goods goods);
  Goods findById(Integer id);
}

2.业务层实现类

@Service
public class GoodsServiceImpl implements GoodsService {
  @Autowired
  private GoodsDao goodsDao;

  @Override
  public List<Goods> findObject() {
    long start=System.currentTimeMillis();
    List<Goods> list = goodsDao.findObjects();
    long end=System.currentTimeMillis();
    System.out.println("query time:"+(end-start));
    return list;
  }

  @Override
  public int add(Goods goods) {
    return goodsDao.add(goods);
  }

  @Override
  public int update(Goods goods) {
    return goodsDao.update(goods);
  }

  @Override
  public Goods findById(Integer id) {
    return goodsDao.findById(id);
  }

控制层写具体实现

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