jsp-错误，因为未正确使用JSTL [英] jsp - error for not correctly use JSTL
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问题描述
我在课堂上有这种方法
public ArrayList<Comuna> getComunas()
{
ConexionBd();
try {
comunas = new ArrayList<Comuna>();
resultado = consulta.executeQuery("select * from comuna");
while(resultado.next())
{
comunas.add(new Comuna(resultado.getInt("com_id"),resultado.getInt("pro_id"),resultado.getString("com_nombre")));
}
CerrarConexionBd();
} catch (Exception e) {
e.printStackTrace();
// TODO: handle exception
}
return comunas;
}
我正在尝试将值放在这里
I'm trying to put the value here
<c:set var="variable" value="${Conexion.getComunas}"></c:set>
并以此显示值
<select class="form-control" id="comuna" name="comuna">
<c:forEach var="comunas" items="${variable} " >
<option value="${comunas.com_id}">${comunas.com_nombre}</option>
</c:forEach>
</select>
我收到此错误javax.el.PropertyNotFoundException:类'java.lang.String'没有属性'com_id'
I get this error javax.el.PropertyNotFoundException : The class 'java.lang.String' does not have the property 'com_id'
at javax.el.BeanELResolver$BeanProperties.get(BeanELResolver.java:229)
at javax.el.BeanELResolver$BeanProperties.access$400(BeanELResolver.java:206)
at javax.el.BeanELResolver.property(BeanELResolver.java:317)
at javax.el.BeanELResolver.getValue(BeanELResolver.java:85)
at org.apache.jasper.el.JasperELResolver.getValue(JasperELResolver.java:104)
at org.apache.el.parser.AstValue.getValue(AstValue.java:183)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:185)
at org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:1026)
at org.apache.jsp.formulario_005fempresa_jsp._jspx_meth_c_005fforEach_005f0(formulario_005fempresa_jsp.java:157)
at org.apache.jsp.formulario_005fempresa_jsp.access$1(formulario_005fempresa_jsp.java:138)
at org.apache.jsp.formulario_005fempresa_jsp$Helper.invoke1(formulario_005fempresa_jsp.java:230)
at org.apache.jsp.formulario_005fempresa_jsp$Helper.invoke(formulario_005fempresa_jsp.java:307)
at org.apache.jsp.tag.webplantillaformulario_tag.doTag(webplantillaformulario_tag.java:130)
at org.apache.jsp.formulario_005fempresa_jsp._jspx_meth_t_005fplantillaformulario_005f0(formulario_005fempresa_jsp.java:112)
at org.apache.jsp.formulario_005fempresa_jsp._jspService(formulario_005fempresa_jsp.java:85)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)`
这是我班的Comuna
this is my class Comuna
public class Comuna {
int com_id;
int pro_id;
String com_nombre;
public Comuna(int com_id, int pro_id, String com_nombre) {
super();
this.com_id = com_id;
this.pro_id = pro_id;
this.com_nombre = com_nombre;
}
public Comuna(){
}
public int getCom_id() {
return com_id;
}
public void setCom_id(int com_id) {
this.com_id = com_id;
}
public int getPro_id() {
return pro_id;
}
public void setPro_id(int pro_id) {
this.pro_id = pro_id;
}
public String getCom_nombre() {
return com_nombre;
}
public void setCom_nombre(String com_nombre) {
this.com_nombre = com_nombre;
}
}
我认为此错误与数据类型有关，但我无法解决，因为 我是新学习的，谢谢
I think this error has to do with the data type, but I cannot solve because because i'am newly learning, thanks
推荐答案
我收到此错误javax.el.PropertyNotFoundException:类
java.lang.String没有属性com_id
问题在下面的行中，错误地在${variable} 之后添加了空格，这就是为什么它被String覆盖并且comunas变为String类型而String却没有的原因没有任何属性com_id.
The problem is at below line where by mistake a space is added after ${variable} that's why it's covered to String and comunas becomes of type String and String doesn't have any property com_id.
<c:forEach var="comunas" items="${variable} " >
只需删除多余的结尾空间即可解决您的问题.
Just removing the extra ending space will solve your problem.
在下面的行中可能还有一个问题，可以从Conexion访问Comunas.
There might be one more issue at below line to access the Comunas from Conexion.
<c:set var="variable" value="${Conexion.getComunas}"></c:set>
应该是
<c:set var="variable" value="${Conexion.getComunas()}"></c:set>
OR
<c:set var="variable" value="${Conexion.comunas}"></c:set>
OR
<c:set var="variable" value="${Conexion['comunas']}"></c:set>
这篇关于jsp-错误，因为未正确使用JSTL的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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