mybatis-plus报错解决Invalid bound statement (not found)错误

异常信息

org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): XXMapper.findTagList

也就是在mybatis中dao层xxxMapper接口与xxxMapper.xml文件在做映射绑定的时候出现问题,也就是xxxMapper接口无法匹配到操作sql语句的方法id~

源码解析

首先断点打在调用mapper方法的地方

tagMapper.findTagList();

继续走，进入MapperMethod.java类:

public SqlCommand(Configuration configuration, Class<?> mapperInterface, Method method) {
      //methodName就是调用的方法名
      final String methodName = method.getName();
      //declaringClass就是 Mapper接口类
      final Class<?> declaringClass = method.getDeclaringClass();
     //问题出在这里 返回为空：原因是没有找到该接口类
      MappedStatement ms = resolveMappedStatement(mapperInterface, methodName, declaringClass,
          configuration);
      if (ms == null) {
        if (method.getAnnotation(Flush.class) != null) {
          name = null;
          type = SqlCommandType.FLUSH;
        } else {
          throw new BindingException("Invalid bound statement (not found): "
              + mapperInterface.getName() + "." + methodName);
        }
      } else {
        name = ms.getId();
        type = ms.getSqlCommandType();
        if (type == SqlCommandType.UNKNOWN) {
          throw new BindingException("Unknown execution method for: " + name);
        }
      }
    }

 private MappedStatement resolveMappedStatement(Class<?> mapperInterface, String methodName,
      Class<?> declaringClass, Configuration configuration) {
    //XXMapper.xxMethod
    String statementId = mapperInterface.getName() + "." + methodName;
    //configuration有一个大集合，缓存了所有的Mapper及所有的方法
    if (configuration.hasStatement(statementId)) {
      return configuration.getMappedStatement(statementId);
    } else if (mapperInterface.equals(declaringClass)) {
      return null;
    }
    for (Class<?> superInterface : mapperInterface.getInterfaces()) {
      if (declaringClass.isAssignableFrom(superInterface)) {
        MappedStatement ms = resolveMappedStatement(superInterface, methodName,
            declaringClass, configuration);
        if (ms != null) {
          return ms;
        }
      }
    }
    return null;
  }
}

　　

问题就在这里 ，mappedStatements没有工程的mapper，原因就是没有扫描到，即定位到扫描时配置问题！

 

解决方案

1. 检查xml映射文件中<mapper>标签绑定包名地址是否正确(即namespace的值)

2. 检查xxxMapper接口中的方法，对应xml映射文件中是否有

3. 检查<select>标签中的resultType是否与xxxMapper接口中的方法返回值类型一致，若一个是对象一个是集合，那也会报错~

4. 检查yml配置文件中的mybatis配置 

配置项 mybatis -> mybatis-plus 

mybatis-plus:
    mapper-locations: classpath*:com/xxx/*Mapper.xml
    typeAliasesPackage: com.xxx.entity

5. xml资源配置

maven:

<build>
          <resources>
              <resource>
                  <directory>src/main/java</directory>
                  <includes>
                      <include>**/*.properties</include>
                      <include>**/*.xml</include>
                      <include>**/*.tld</include>
                  </includes>
                  <filtering>true</filtering>
              </resource>
          </resources>
  </build>

gradle:

processResources {
    from('src/main/java') {
        include '**/xml/*.xml'
    }
}

　　

问题解决！