Error starting ApplicationContext. To display the conditions report re-run your application with ···

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
30.237 ERROR o.s.boot.SpringApplication    :843  main                    Application run failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userService': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userMapper' defined in file [E:\java\springboot01\target\classes\com\lxc\springboot01\mapper\UserMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\java\springboot01\target\classes\mapper\userMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 6; 不允许有匹配 "[xX][mM][lL]" 的处理指令目标。

 八成是 xml中第一行有空格或者注释造成的

 把注释或空格删掉，<?xml 放在第一行。