相关疑难解决方法(0)

我不知道我做错了什么,但我不能包括JSTL.我有jstl-1.2.jar,但不幸的是我得到了例外:

org.apache.jasper.JasperException: The absolute uri: http://java.sun.com/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application
    at org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:51)
    at org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:409)
    at org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:116)
    at org.apache.jasper.compiler.TagLibraryInfoImpl.generateTLDLocation(TagLibraryInfoImpl.java:315)
    at org.apache.jasper.compiler.TagLibraryInfoImpl.<init>(TagLibraryInfoImpl.java:148)
    at org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:429)
    at org.apache.jasper.compiler.Parser.parseDirective(Parser.java:492)
    at org.apache.jasper.compiler.Parser.parseElements(Parser.java:1439)
    at org.apache.jasper.compiler.Parser.parse(Parser.java:137)
    at org.apache.jasper.compiler.ParserController.doParse(ParserController.java:255)
    at org.apache.jasper.compiler.ParserController.parse(ParserController.java:103)
    at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:170)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:332)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:312)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:299)
    at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:586)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) …

 double d = 4.321562;

有没有一种简单的方法从d中提取0.321562？我试着看数学课,但没有运气.如果这可以在不转换为字符串或转换为其他任何内容的情况下完成,甚至更好.

假设我们有双重值12345.6789(应该是动态的)

现在要求是将数字拆分并得到小数位数和小数位数,这将是:

double number = 12345.6789;
int decimal = 12345;
int fractional = 6789;

我得到了小数部分,但是你能不能给出小数部分的提示？非常感谢.

我试图将一个double分成整数和小数部分

例如,数字24.4应分为24和4.

int integer = (int)number;
double decimal = number-(int)number;
System.out.println(decimal); 

使用此方法为我提供以下值:

integer = 24
decimal = 0.3999999999999986

我需要十进制的值为4.

如何解决这个问题？