小柯博客

2023-03-20

2023-03-20 / 548阅读 / 0评论 / 1点赞

默认分类

2023-02-27

Java基础之删除list中的某个元素

```java List<String> list = new ArrayList<>(); list.add("小白"); list.add("jack"); list.add("小强"); list.add("jack"); // 删除 jack list.removeIf(next -> next.equals("jack")); System.out.println(list); ``` ![](https://xkbk.top/uploads/20230227/cace640a569107cfdc5c2b8c6a06f19b.png)

2023-02-27 / 558阅读 / 2评论 / 0点赞

Java

2023-02-11

Spring整合Mybatis

### 1.导入坐标 ```xml <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>5.2.10.RELEASE</version> </dependency> <dependency>  <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.2.10.RELEASE</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.1.16</version> </dependency> <dependency>  <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.3.0</version> </dependency>  <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.6</version> </dependency>  <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.31</version> </dependency> ``` ### 2.创建数据库连接信息 jdbc.properties ``` jdbc.driver=com.mysql.cj.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/spring_db?useSSL=false jdbc.username=root jdbc.password=658575 ``` ### 3.创建jdbc配置对象 ```java package com.spring.config; import com.alibaba.druid.pool.DruidDataSource; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import javax.sql.DataSource; public class JdbcConfig { @Value("${jdbc.driver}") private String driver; @Value("${jdbc.url}") private String url; @Value("${jdbc.username}") private String userName; @Value("${jdbc.password}") private String password; // 创建一个连接池 @Bean public DataSource dataSource(){ DruidDataSource ds = new DruidDataSource(); ds.setDriverClassName(driver); ds.setUrl(url); ds.setUsername(userName); ds.setPassword(password); return ds; } } ``` ### 4.创建Mybatis配置对象 ```java package com.spring.config; import org.mybatis.spring.SqlSessionFactoryBean; import org.mybatis.spring.mapper.MapperScannerConfigurer; import org.springframework.context.annotation.Bean; import javax.sql.DataSource; public class MybatisConfig { //定义bean，SqlSessionFactoryBean，用于产生SqlSessionFactory对象 // dataSource 依赖 jdbcConfig 的 bean @Bean public SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource){ SqlSessionFactoryBean ssfb = new SqlSessionFactoryBean(); ssfb.setTypeAliasesPackage("com.spring.domain"); ssfb.setDataSource(dataSource); return ssfb; } //定义bean，返回MapperScannerConfigurer对象 @Bean public MapperScannerConfigurer mapperScannerConfigurer(){ MapperScannerConfigurer msc = new MapperScannerConfigurer(); msc.setBasePackage("com.spring.dao"); return msc; } } ``` #### 5.引入配置对象 SpringConfig ```java package com.spring.config; 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 @ComponentScan("com.spring") @PropertySource("classpath:jdbc.properties") @Import({JdbcConfig.class,MybatisConfig.class}) public class SpringConfig { } ```

2023-02-11 / 615阅读 / 0评论 / 1点赞

Java

2023-02-08

Error:java: 不再支持源选项 5。请使用 6 或更高版本这个问题的解决方法

### 第一步，点File ->Settings，找到Java Compiler项，确认其中的版本是11，而不是5. ![](https://xkbk.top/uploads/20230208/61dd07cb33a73ecd02acf47dd80bb20b.png) ### 第二步，通过File->Project Structure，进入到另外一个配置页面。 ![](https://xkbk.top/uploads/20230208/b59f47f9dc777d41a662bd9c3df7af01.png) ### 首先确认Project里的版本是11. ![](https://xkbk.top/uploads/20230208/9aa10cf12c6fb6bf9dd1937159d7c1f9.png) ### 再确认Modules里的也是11. ![](https://xkbk.top/uploads/20230208/7cf4fd62b71f0cf5725cc128c3e12c48.png)

2023-02-08 / 623阅读 / 0评论 / 0点赞

Java