SpringBoot整合mybatis常见问题(小结)

Spring中常见问题

1.NoSuchBeanDefinitionException

2.'..Service' that could not be found service找不到

3.port 80 was already in use 端口号被占用

4.TemplateInputException 模板解析异常或找不到模板

• 1.检查模板所在的目录是否与配置的前缀目录相同

• 2.检查返回的模板是否存在,返回值类型是否一致

• 3.检查配置前缀时是否以"/"斜杠结尾

• 4.控制层的url与客户端的ur是否一致

5. 404异常 访问资源不存在

6. 500异常 500异常要查看控制台

Mybatis中常见问题

1.springboot中添加maven依赖

2.BadSqlGrammarException 错误的sql语句

3.BindingException 绑定异常

• 1.检查映射文件的路径配置与实际存储位置是否一致

• 2.检查dao接口的类名是否与映射文件的namespace值相同(不能有空格)

• 3.检查dao接口中的方法名是否在映射文件中有对应的id

4.IllegalArgumentException

原因:同样说我sql映射是否出现了重复性的定义(例如:分别以注解方式和xml配置文件方式进行定义,也就是说在同一个namespace下出现了重复的元素id)

5.SAXParseException xml解析问题

补充

问题一：Mapper类 autowired失败

原因：扫描mapper包没有配置或配置不正确

解决：

方案一：

1. 启动类加@MapperScan("mapperPackagePath")

方案二：

增加配置类：

package com.yx.readingwebsite.config;

import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
* MapperScannerConfigurer 配置DAO层
*/

@Configuration
public class MyBatisMapperScannerConfig {
 @Bean
 public MapperScannerConfigurer getMapperScannerConfigurer(){
   MapperScannerConfigurer msc = new MapperScannerConfigurer();
   msc.setSqlSessionFactoryBeanName("sqlSessionFactory");
   msc.setBasePackage("com.yx.readingwebsite.mapper");
   return msc;
 }
}

问题二：Mapper扫描成功后，继续报错，org.apache.ibatis.binding.BindingException: Invalid bound statement (not found):

原因：xml的mapper SQL 和 Mapper接口没有绑定

解决：

方案一：全局配置文件application.yml增加mybatis配置【xml mapper包在resource目录下】

mybatis:
mapper-locations: classpath:mapper/*.xml

方案二：增加配置类

package com.yx.readingwebsite.config;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import org.springframework.transaction.annotation.TransactionManagementConfigurer;

import javax.sql.DataSource;

/**
* 配置MyBatis,引入数据源，sqlSessionFactory,sqlSessionTemplate,事务管理器
*/

@Configuration //配置类
@EnableTransactionManagement //允许使用事务管理器
public class MyBatisModelConfig implements TransactionManagementConfigurer {

@Autowired
 private DataSource dataSource;

@Bean(name = "sqlSessionFactory")
 public SqlSessionFactory getSqlSessionFactory(){
   SqlSessionFactoryBean ssfb = new SqlSessionFactoryBean();
   ssfb.setDataSource(dataSource); //设置数据源
   ssfb.setTypeAliasesPackage("com.yx.readingwebsite.model");  //设置扫描模型包【po】
   try {
     Resource[] resources = new PathMatchingResourcePatternResolver()
         .getResources("classpath:mapper/*.xml");
     ssfb.setMapperLocations(resources);
     return ssfb.getObject();
   } catch (Exception e) {
     e.printStackTrace();
     throw new RuntimeException();
   }
 }

@Bean  //获得Session 模板，从而获得Session
 public SqlSessionTemplate getSqlSessionTemplate(SqlSessionFactory sqlSessionFactory){
   return new SqlSessionTemplate(sqlSessionFactory);
 }

@Override  //事务管理器
 public PlatformTransactionManager annotationDrivenTransactionManager() {
   return new DataSourceTransactionManager(dataSource);
 }
}

需要注意的是，xml版的mybatis一定要在sqlSessionFactory中指定mapperLocations,即下图

总结：
两种配置方案。方案一，使用配置类；方案二，使用配置文件。完整配置如下：

方案一：配置类

package com.yx.readingwebsite.config;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import org.springframework.transaction.annotation.TransactionManagementConfigurer;

import javax.sql.DataSource;

/**
* 配置MyBatis,引入数据源，sqlSessionFactory,sqlSessionTemplate,事务管理器
*/

@Configuration //配置类
@EnableTransactionManagement //允许使用事务管理器
public class MyBatisModelConfig implements TransactionManagementConfigurer {

@Autowired
 private DataSource dataSource;

@Bean(name = "sqlSessionFactory")
 public SqlSessionFactory getSqlSessionFactory(){
   SqlSessionFactoryBean ssfb = new SqlSessionFactoryBean();
   ssfb.setDataSource(dataSource); //设置数据源
   ssfb.setTypeAliasesPackage("com.yx.readingwebsite.model");  //设置扫描模型包【po】
   try {
     Resource[] resources = new PathMatchingResourcePatternResolver()
         .getResources("classpath:mapper/*.xml");
     ssfb.setMapperLocations(resources);
     return ssfb.getObject();
   } catch (Exception e) {
     e.printStackTrace();
     throw new RuntimeException();
   }
 }

@Bean  //获得Session 模板，从而获得Session
 public SqlSessionTemplate getSqlSessionTemplate(SqlSessionFactory sqlSessionFactory){
   return new SqlSessionTemplate(sqlSessionFactory);
 }

@Override  //事务管理器
 public PlatformTransactionManager annotationDrivenTransactionManager() {
   return new DataSourceTransactionManager(dataSource);
 }
}

package com.yx.readingwebsite.config;

import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
* MapperScannerConfigurer 配置DAO层
*/

@Configuration
@AutoConfigureAfter(MyBatisModelConfig.class)
public class MyBatisMapperScannerConfig {
 @Bean
 public MapperScannerConfigurer getMapperScannerConfigurer(){
   MapperScannerConfigurer msc = new MapperScannerConfigurer();
   msc.setSqlSessionFactoryBeanName("sqlSessionFactory");
   msc.setBasePackage("com.yx.readingwebsite.mapper");
   return msc;
 }
}

方案二：配置文件 application.yml

spring:
datasource:
 url: jdbc:mysql://127.0.0.1:3306/readingWebsite?useUnicode=true&characterEncoding=utf-8
 username:
 password:
 driver-class-name: com.mysql.jdbc.Driver
 max-active: 100
 max-idle: 10
 max-wait: 10000
 default-auto-commit: false
 time-between-eviction-runs-millis: 30000
 min-evictable-idle-time-millis: 30000
 test-while-idle: true
 test-on-borrow: true
 test-on-return: true
 validation-query: SELECT 1

mybatis:
mapper-locations: classpath:mapper/*.xml

package com.yx.readingwebsite;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.yx.readingwebsite")
public class ReadingWebsiteApplication {

public static void main(String[] args) {
   SpringApplication.run(ReadingWebsiteApplication.class, args);
 }

}

来源：https://segmentfault.com/a/1190000038641171