学习 springboot 中出现的问题

谁践踏了优雅 2021-12-12 10:45 202阅读 0赞

**目录**

1.首先可能是springboot静态资源访问不到

2.下面是整和mybatis的时候mapper 文件产生的问题，不映射的问题，检查一下方面，如果还出现错误，我就无能为力了

1.首先你的mapper.xml 的namespace 一定要对应到类 ，我写是时候对应到包，我就错了，好气气

2.@MapperScan("com.example.demo.mapper")记得加上这个 ,@mapper记得也要加上，

3.一定要指定一下mapper 的路径

4,。如果还不行的话，加上这个东西，在pom 文件下

5.检查一下依赖

3.springboot 中test测试类自动注入进不来的问题：

--------------------

# 1.首先可能是springboot静态资源访问不到 #

这个springboot 2.0以上出现的问题，拦截器会拦截静态资源，

在自动注入的时候，覆盖了路径，需要重写

package com.ak.springboot02.config;
    
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
    import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
    
    @Configuration
    public class MyMvcConfig extends WebMvcConfigurationSupport {
    
        protected void addViewControllers(ViewControllerRegistry registry) {
            registry.addViewController("/").setViewName("login");
        }
    
        @Override
        protected void addResourceHandlers(ResourceHandlerRegistry registry) {
            registry.addResourceHandler("/**")
                    .addResourceLocations("classpath:/resources/")
                    .addResourceLocations("classpath:/static/")
                    .addResourceLocations("classpath:/public/");
    
            super.addResourceHandlers(registry);
        }
    
    }

# 2.下面是整和mybatis的时候mapper 文件产生的问题，不映射的问题，检查一下方面，如果还出现错误，我就无能为力了 #

映射产生的问题

### 1.首先你的mapper.xml 的namespace 一定要对应到类 ，我写是时候对应到包，我就错了，好气气 ###

然后呢你的xml 文件要放在 包下面扫描的时候就不会出现问题

### 2.@MapperScan("com.example.demo.mapper")记得加上这个 ,**@mapper记得也要加上，** ###

package com.example.demo;
    
    import org.mybatis.spring.annotation.MapperScan;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.web.servlet.ServletComponentScan;
    
    @SpringBootApplication
    @MapperScan("com.example.demo.mapper")
    public class DemoApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(DemoApplication.class, args);
        }
    
    }

### 3.一定要指定一下mapper 的路径 ###

mybatis.mapper-locations=classpath*:com/example/demo/mapper/*.xml

### 4,。如果还不行的话，加上这个东西，在pom 文件下 ###

<build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
    
    
            <resources>
                <resource>
                    <directory>src/main/resources</directory>
                </resource>
                <resource>
                    <directory>src/main/java</directory>
                    <filtering>true</filtering>
                    <includes>
                        <include>**/*.xml</include>
                    </includes>
                </resource>
            </resources>
    
        </build>

### 5.检查一下依赖 ###

<dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
    
            <dependency>
                <groupId>org.webjars</groupId>
                <artifactId>jquery</artifactId>
                <version>3.4.1</version>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
            </dependency>
            <dependency>
                <groupId>org.thymeleaf</groupId>
                <artifactId>thymeleaf-spring5</artifactId>
            </dependency>
            <dependency>
                <groupId>org.thymeleaf.extras</groupId>
                <artifactId>thymeleaf-extras-java8time</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-thymeleaf</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-jdbc</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-jpa</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-jdbc</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.data</groupId>
                <artifactId>spring-data-jdbc</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-configuration-processor</artifactId>
            </dependency>
    
        </dependencies>

# 3.springboot 中test测试类自动注入进不来的问题： #

@RunWith(SpringRunner.class)
    @SpringBootTest
    public class Springboot02ApplicationTests {
    
        @Autowired
        DataSource dataSource;
    
        @Autowired
        int k1;
    
        @Test
        public void contextLoads() throws Exception{
    
            System.out.println(k1);
    //        System.out.println(dataSource.getClass());
    //
    //        Connection connection=dataSource.getConnection();
    //
    //
    //        System.out.println(connection);
    //
    //        connection.close();
        }
    
    }

上面一直报错 ，说自动注入不进来？

package com.test1.demo1;
    
    import com.example.demo.DemoApplication;
    import com.example.demo.mapper.StudentMapper;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    
    import javax.sql.DataSource;
    
    @RunWith(SpringRunner.class)
    @SpringBootTest(classes = DemoApplication.class)
    public class Demo1ApplicationTests {
    
    
        @Autowired
        private StudentMapper studentMapper;
    
    
        @Test
        public void contextLoads() {
    
           System.out.println(studentMapper.getStudentBySno(1));
    
        }
    
    }

这样子就好了，

修改

@SpringBootTest(classes = DemoApplication.class)

这样子就好了。

以上就是昨天学习springboot 出现的一系列问题，今天继续写哈哈。

遨游在报错的海洋中