ireport对分组统计问题
变量countnum设定:
variable class type : java.lang.integer
calculation type : count
reset type : group
reset group : projectgroup(组名)
variable expression : $F{STATISTICS_ID}(某字段)
运行出现错误:
net.sf.jasperreports.engine.JRException: Errors were encountered when compiling report expressions class file: 1. Cannot cast from Integer to String value = (java.lang.String)(((java.lang.Integer)variable_countnum.getValue())); <-------------------------------------------------------------------> 2. Cannot cast from Integer to String value = (java.lang.String)(((java.lang.Integer)variable_countnum.getOldValue())); <----------------------------------------------------------------------> 3. Cannot cast from Integer to String value = (java.lang.String)(((java.lang.Integer)variable_countnum.getEstimatedValue())); <----------------------------------------------------------------------------> 3 errors at net.sf.jasperreports.engine.design.JRAbstractCompiler.compileReport(JRAbstractCompiler.java:193) at net.sf.jasperreports.engine.design.JRDefaultCompiler.compileReport(JRDefaultCompiler.java:131) at net.sf.jasperreports.engine.JasperCompileManager.compileReportToFile(JasperCompileManager.java:127) at net.sf.jasperreports.engine.JasperCompileManager.compileReportToFile(JasperCompileManager.java:109) at it.businesslogic.ireport.IReportCompiler.run(IReportCompiler.java:473) at java.lang.Thread.run(Unknown Source)
请问这是为什么?一统计这个分组记录数就出现以上错误,还请各位指点一下,谢谢