Real-time weather forecast interface

Simple method, you can directly build this xml in doGet or doPost of servlet, and then write back the response.

You need to build a java application server, such as tomcat server, and just run this servlet.

There are many tools to build xml for Java, such as JDOM and Dom4J.

If the client needs a web service, you can consider a Java Web service framework such as Apache CXF, but it is generally unnecessary.