mybatis-plus報錯解決Invalid bound statement (not found)錯誤

異常信息

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

也就是在mybatis中dao層xxxMapper接口與xxxMapper.xml文件在做映射綁定的時候出現問題,也就是xxxMapper接口無法匹配到操作sql語句的方法id~

源碼解析

首先斷點打在調用mapper方法的地方

tagMapper.findTagList();

繼續走，進入MapperMethod.java類:

public SqlCommand(Configuration configuration, Class<?> mapperInterface, Method method) {
      //methodName就是調用的方法名
      final String methodName = method.getName();
      //declaringClass就是 Mapper接口類
      final Class<?> declaringClass = method.getDeclaringClass();
     //問題出在這裏 返回爲空：原因是沒有找到該接口類
      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有一個大集合，緩存了所有的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;
  }
}

　　

問題就在這裏 ，mappedStatements沒有工程的mapper，原因就是沒有掃描到，即定位到掃描時配置問題！

 

解決方案

1. 檢查xml映射文件中<mapper>標籤綁定包名地址是否正確(即namespace的值)

2. 檢查xxxMapper接口中的方法，對應xml映射文件中是否有

3. 檢查<select>標籤中的resultType是否與xxxMapper接口中的方法返回值類型一致，若一個是對象一個是集合，那也會報錯~

4. 檢查yml配置文件中的mybatis配置 

配置項 mybatis -> mybatis-plus 

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

5. xml資源配置

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'
    }
}

　　

問題解決！