java - 将字符串解析为 double 得到错误 java.lang.NumberFormatException : empty String

Question

当我计算字符串值时出现此错误:Double.toString(Double.parseDouble(suggestionSortScore) - 6)

17:47:19,983 INFO [STDOUT] [EDS ALL LIST] NOC BLACK LIST : Sugeng Hindarjo

17:47:19,984 ERROR [[jsp]] Servlet.service() for servlet jsp threw exception java.lang.NumberFormatException: empty String at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:994) at java.lang.Double.parseDouble(Double.java:510) at org.apache.jsp.WEB_002dINF.jsp.n51Alist_jsp.getTransactionsFromIpg(n51Alist_jsp.java:380) at org.apache.jsp.WEB_002dINF.jsp.n51Alist_jsp._jspService(n51Alist_jsp.java:581) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:336) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) 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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:654) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:445) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:379) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:292) at nsia.owasp.util.Controller.doPost(Controller.java:166) at javax.servlet.http.HttpServlet.service(HttpServlet.java:710) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262) at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:437) at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:366) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446) at java.lang.Thread.run(Thread.java:662) 17:47:19,984 INFO [STDOUT] Exception => org.apache.jasper.JasperException: An exception occurred processing JSP page /WEB-INF/jsp/n51Alist.jsp at line 370

367: if(cekBlackListByNoc==true){

368: System.out.println("[EDS ALL LIST] NOC BLACK LIST : " + nameOnCardDecrypt);

369: data[0] = "yellow";

370: data[17] = Double.toString(Double.parseDouble(suggestionSortScore) - 6);

371: if (Double.parseDouble(data[17]) < 3.0) {

372: data[17] = "3.1";

373: }

为什么堆栈跟踪显示空字符串？ suggestsortscore 填充值“5.0”。

Answer 1

Double.toString(Double.parseDouble(suggestionSortScore) - 6) -- 仅当字符串 suggestionSortScore 不包含可解析的 double< 时才会出现异常