JSTL里的自定义中定义函数的连接字符怎么
我是用el隐士变量连接字符串，用+号，不用+怎么都不对，
例如这样写就是对的
${kanbafn:str(pageContext.request.scheme)}
但是如果我任意给pageContext.request.scheme连接个字符串传过去就有错误
例如：${kanbafn:str(pageContext.request.scheme+"a")}
${kanbafn:str(pageContext.request.scheme"a")}
这两种都不对，反正就是有异常
[b]问题补充：[/b]
[code="java"]
${kanbafn:str(pageContext.request.scheme+a)} [/code]
这样写提示
[code="java"]java.lang.NumberFormatException: For input string: "http"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Long.parseLong(Long.java:403)
at java.lang.Long.(Long.java:671)
at org.apache.el.lang.ELArithmetic$LongDelegate.coerce(ELArithmetic.java:188)
at org.apache.el.lang.ELArithmetic.coerce(ELArithmetic.java:356)
at org.apache.el.lang.ELArithmetic.add(ELArithmetic.java:237)
at org.apache.el.parser.AstPlus.getValue(AstPlus.java:24)
at org.apache.el.parser.AstFunction.getValue(AstFunction.java:85)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
at org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:923)
at org.apache.jsp.test_jsp._jspService(test_jsp.java:86)
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:393)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
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 com.kanba.filter.EncodingFilter.doFilter(EncodingFilter.java:26)
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:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
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:263)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)[/code]
去年+a就正确了
