java web developer interview questions

field is empty (null), it is not recommended to Jianjian the word index.Please remember that there must be a business need to build the index. For example, in a commodity table, we often have to query according to name, if there is no index, query speed is very slow, then we need to build an index. However, in project development, it is not necessary to index a number if it is not often queried according to the product number.Finally, the index is to pay a price, nothing to build, at the same t

Computer questions (Elementary)-Java Network Operations-printing web pages (Java) Print a webpage and be familiar with Java Network Programming: import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.n

I. Explanations of the following J2EE terms(1) JNDI: Java Naming Directory Interface, Java Naming directory service. the main function is to provide a directory system that allows applications from other places to leave their own indexes on it to quickly find and locate distributed applications.(2) JMS: Java Message Service,

second variable, it must be explicitly initialized. If you try to use it before it is initialized, the compiler will protest. If the initialized statement is in a try block or an if block, it must be assigned before the first use. That is, the compiler will also protest if the initialization statement is placed in a conditional judgment statement with only the If block, because execution may not conform to the judgment condition after the IF, so that the initialization statement is not executed

Consistent, value is UTF-82) browser display character encoding consistent with the requested JSP page encoding2. get The Chinese parameter value in the JSP page: the encoding used by the default parameter in transit is iso-8859-11) for post requests: call request.setcharacterencoding ("UTF-8") before getting the parameters;1 2 request.setcharacterencoding ("UTF-8");3 4 %>5Username=Request.getparameter ("username") %>　　2) for GET requests:① first get the parameters, then decode, then e

following statements is true? (Single choice)Option:(A) For each HTTP request requesting access to maillogin. jsp, the servlet container creates an httpsession object.(B) Each httpsession object has a unique ID.(C) The Java Web application must assign a unique ID to the httpsession. (11) What should I do if I do not want JSP pages to support sessions? (Single choice)Option:(A) call the invalidate () method