public List findCatalog() {
Query query = getEntityManager().createQuery("SELECT pc.productCatalog, p.name, p.product FROM ProductCatalog pc JOIN pc.products p");
return query.getResultList();
}
你好,用这样的查询我的应用程序编译好了。但是当我打开其中执行此查询我碰到下面的错误页面:尝试呈现查询中的值后出现java.lang.NumberFormatException
org.apache.jasper.JasperException: java.lang.NumberFormatException: For input string: "productCatalog"
的productCatalog是我的主键,但同样的情况时,我只是包括名称列
exception org.apache.jasper.JasperException: java.lang.NumberFormatException: For input string: "name" root cause
java.lang.NumberFormatException: For input string: "name"
如果我不要在我的查询中进行连接,那么1个表格的结果就会打印好。 我对现在的问题无能为力,我已经阅读了专业JPA 2书籍,官方的Java EE 6教程,Google搜索了很多。 表格设计是ManyToMany。我有产品表,* product_catalog *表和绑定表* product_product_catalog。绑定表中没有外键。 我使用NetBeans EclipseLink向导创建了实体和外观类。
这是我如何映射到我的ProductCatalog类多对多的关系
@ManyToMany
@JoinTable(name = "product_product_catalog",
joinColumns = {
@JoinColumn(name = "product_catalog")
},
inverseJoinColumns = {
@JoinColumn(name = "product")
})
private Collection<Product> products;
产品,并在PRODUCT_CATALOG的主键对应表。 现在我不知道我可能会出错,也许是映射错误?虽然我见过的很多例子都有相同的映射实现,但在他们的表中它们有外键,这可能是一个问题吗?此外,正如我所说,如果我不加入第二张桌子,一切运作良好。
这里是我的servlet与初始化该方法getServletContext().setAttribute("productCatalog", productCatalogFacade.findCatalog());
这里是我的那
<table>
<c:forEach var="list" items="${productCatalog}" varStatus="iter">
<tr>
<td>${list.productCatalog}</td>
<td>${list.product}</td>
<td>${list.name}</td>
</tr>
</c:forEach>
</table>
JSP页面片段,这是我的原生SQL查询我想要实现
SELECT PPC.product_product_catalog, PPC.product_catalog, PPC.product, P.name, PC.name AS "catalog name", P.code, P.description, P.price, P.producer
FROM product_catalog PC
INNER JOIN product_product_catalog PPC ON PC.product_catalog = PPC.product_catalog
INNER JOIN product P ON P.product = PPC.product
由于我最后一段代码是当我去那个查询执行页面时glassfish产生的输出:
WARNING: StandardWrapperValve[jsp]: PWC1406: Servlet.service() for servlet jsp threw exception
java.lang.NumberFormatException: For input string: "productCatalog"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Integer.parseInt(Integer.java:449)
at java.lang.Integer.parseInt(Integer.java:499)
at javax.el.ArrayELResolver.toInteger(ArrayELResolver.java:375)
at javax.el.ArrayELResolver.getValue(ArrayELResolver.java:195)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:175)
at com.sun.el.parser.AstValue.getValue(AstValue.java:116)
at com.sun.el.parser.AstValue.getValue(AstValue.java:163)
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:219)
at org.apache.jasper.runtime.PageContextImpl.evaluateExpression(PageContextImpl.java:1007)
at org.apache.jsp.index_jsp._jspx_meth_c_forEach_0(index_jsp.java from :206)
at org.apache.jsp.index_jsp._jspService(index_jsp.java from :137)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:109)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:406)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:483)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:373)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
at java.lang.Thread.run(Thread.java:619)
您期望的列表是什么?你得到什么名单?调试。 – Bozho 2011-02-24 23:02:14
嘿,我除了product_catalog.product_catalog,product.product,product.name,product_catalog.catalog_name,product.code 基本上来自2个表的结果。 我已经在我的问题中包含一个本机SQL查询我试图用JPQL – Skyzer 2011-02-24 23:14:06