javax.servlet jar是專為開發(fā)者打造的一款java依融包，javax.servlet.jar包可以解決找不到j(luò)avax.servlet.*等問題，如果在提示的時(shí)候提示不存，可以在本站下載然后放到指定的目錄后就可以正常使用了，需要此款jar包的朋友們歡迎前來下載使用。

常見問題

編譯時(shí)錯(cuò)誤：軟件包 javax.servlet.http 不存在import javax.servlet.http.HttpServletRequest;

解決辦法：

1、 把servlet-api.jar加到classpath中，如

把%CATALINA_HOME%\lib;%CATALINA_HOME%\lib\servlet-api.jar;%CATALINA_HOME%\lib\jsp-api.jar 加到classpath變量的后面。

2、 把Tomcat目錄下的 tomcat\lib\servlet-api.jar 拷貝到 Java\jdk1.6.0_22\jre\lib\ext 目錄下。

3、 javac時(shí)把相關(guān)的類沒有加到-classpath選項(xiàng)中去，如：

編譯時(shí)使用：javac -classpath ./test.jar TestJar.java

運(yùn)行時(shí)使用：java -cp .:./test.jar TestJar 才可以運(yùn)行。

請(qǐng)問這里為什么javac使用-classpath，java使用-cp?難道classpath不等價(jià)于cp? 沒有區(qū)別，除了一個(gè)是縮寫，一個(gè)是全稱之外，功能是一模一樣的。

包括：

javax.servlet.Filter

javax.servlet.Servlet

javax.servlet.FilterChain

javax.servlet.http.Cookie

javax.servlet.jsp.JspPage

javax.servlet.FilterConfig

javax.servlet.ServletConfig

javax.servlet.jsp.ErrorData

javax.servlet.jsp.JspWriter

javax.servlet.GenericServlet

javax.servlet.ServletContext

javax.servlet.ServletRequest

javax.servlet.http.HttpUtils

javax.servlet.jsp.JspContext

javax.servlet.jsp.JspFactory

javax.servlet.jsp.tagext.Tag

javax.servlet.ServletResponse

javax.servlet.jsp.HttpJspPage

javax.servlet.jsp.PageContext

javax.servlet.ServletException

javax.servlet.http.HttpServlet

javax.servlet.http.HttpSession

javax.servlet.jsp.JspException

javax.servlet.RequestDispatcher

javax.servlet.SingleThreadModel

javax.servlet.jsp.JspEngineInfo

javax.servlet.jsp.el.Expression

javax.servlet.jsp.tagext.JspTag

javax.servlet.ServletInputStream

javax.servlet.jsp.el.ELException

javax.servlet.jsp.tagext.BodyTag

javax.servlet.jsp.tagext.TagData

javax.servlet.jsp.tagext.TagInfo

javax.servlet.ServletContextEvent

javax.servlet.ServletOutputStream

javax.servlet.ServletRequestEvent

javax.servlet.http.NoBodyResponse

javax.servlet.jsp.JspTagException

javax.servlet.jsp.tagext.PageData

javax.servlet.UnavailableException

javax.servlet.jsp.tagext.SimpleTag

javax.servlet.ServletRequestWrapper

javax.servlet.http.HttpSessionEvent

javax.servlet.jsp.SkipPageException

javax.servlet.jsp.el.FunctionMapper

javax.servlet.jsp.tagext.TagAdapter

javax.servlet.jsp.tagext.TagSupport

javax.servlet.ServletContextListener

javax.servlet.ServletRequestListener

javax.servlet.ServletResponseWrapper

javax.servlet.jsp.tagext.BodyContent

javax.servlet.jsp.tagext.JspFragment

javax.servlet.jsp.tagext.TagFileInfo

javax.servlet.http.HttpServletRequest

javax.servlet.http.HttpSessionContext

javax.servlet.http.NoBodyOutputStream

javax.servlet.jsp.el.ELParseException

javax.servlet.jsp.el.VariableResolver

javax.servlet.jsp.tagext.FunctionInfo

javax.servlet.jsp.tagext.IterationTag

javax.servlet.jsp.tagext.TagExtraInfo

javax.servlet.jsp.tagext.VariableInfo

javax.servlet.http.HttpServletResponse

javax.servlet.http.HttpSessionListener

javax.servlet.jsp.tagext.BodyTagSupport

javax.servlet.jsp.tagext.TagLibraryInfo

javax.servlet.jsp.el.ExpressionEvaluator

javax.servlet.jsp.tagext.TagVariableInfo

javax.servlet.jsp.tagext.TryCatchFinally

javax.servlet.jsp.tagext.SimpleTagSupport

javax.servlet.jsp.tagext.TagAttributeInfo

javax.servlet.ServletContextAttributeEvent

javax.servlet.ServletRequestAttributeEvent

javax.servlet.http.HttpSessionBindingEvent

javax.servlet.jsp.tagext.DynamicAttributes

javax.servlet.jsp.tagext.ValidationMessage

javax.servlet.http.HttpServletRequestWrapper

javax.servlet.jsp.tagext.TagLibraryValidator

javax.servlet.ServletContextAttributeListener

javax.servlet.ServletRequestAttributeListener

javax.servlet.http.HttpServletResponseWrapper

javax.servlet.http.HttpSessionBindingListener

javax.servlet.http.HttpSessionAttributeListener

javax.servlet.http.HttpSessionActivationListener