Beans : The root node of the XML file.
xmlns : the abbreviation for XML namespace, because the tag name of the XML file is customized, and the tags that are written by yourself and others are likely to be named repeatedly, but the functions are different. So you need to add a namespace to differentiate this XML file from other XML files, similar to the package in Java
xmlns:xsi : XML file adheres to XML specification, XSI full name: XML Schema instance, refers to the specification of the elements defined in the schema resource file used specifically. That is,/spring-beans-2.0.xsd the elements defined in this file adhere to what standards
xsi:schemalocation : The XML element in this document complies with the specification, the schemalocation attribute is used to reference (schema) schema documents, and the parser can use this document to verify the XML instance document as needed. Its value (URI) is in pairs, the first value represents the namespace, the second value represents the specific location of the schema document that describes the namespace, and two values are separated by a space
Spring configuration file XML--Overview of properties in <beans>