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,用這樣的查詢我的應用程序編譯好了。但是當我打開其中執行此查詢我碰到下面的錯誤頁面:嘗試呈現查詢中的值後出現java.lang.NumberFormatException
org.apache.jasper.JasperException: java.lang.NumberFormatException: For input string: "productCatalog"
的productCatalog是我的主鍵,但同樣的情況時,我只是包括名稱列
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詢中進行連接,那麼1個表格的結果就會打印好。 我對現在的問題無能爲力,我已經閱讀了專業JPA 2書籍,官方的Java EE 6教程,Google搜索了很多。 表格設計是ManyToMany。我有產品表,* product_catalog *表和綁定表* product_product_catalog。綁定表中沒有外鍵。 我使用NetBeans EclipseLink嚮導創建了實體和外觀類。
這是我如何映射到我的ProductCatalog類多對多的關係
@ManyToMany
@JoinTable(name = "product_product_catalog",
joinColumns = {
@JoinColumn(name = "product_catalog")
},
inverseJoinColumns = {
@JoinColumn(name = "product")
})
private Collection<Product> products;
產品,並在PRODUCT_CATALOG的主鍵對應表。 現在我不知道我可能會出錯,也許是映射錯誤?雖然我見過的很多例子都有相同的映射實現,但在他們的表中它們有外鍵,這可能是一個問題嗎?此外,正如我所說,如果我不加入第二張桌子,一切運作良好。
這裏是我的servlet與初始化該方法getServletContext().setAttribute("productCatalog", productCatalogFacade.findCatalog());
這裏是我的那
<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頁面片段,這是我的原生SQL查詢我想要實現
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
由於我最後一段代碼是當我去那個查詢執行頁面時glassfish產生的輸出:
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)
您期望的列表是什麼?你得到什麼名單?調試。 – 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 基本上來自2個表的結果。 我已經在我的問題中包含一個本機SQL查詢我試圖用JPQL – Skyzer 2011-02-24 23:14:06