工作了一個(gè)多月，不管從工作行業(yè)還是工作性質(zhì)，我都是一個(gè)新手，總結了一下工作中經(jīng)常遇到的問(wèn)題，以方便查找參考，由于水平有限，也希望看到該文章的專(zhuān)業(yè)朋友給與指點(diǎn)。
java.lang.OutOfMemoryError: PermGen space
未解決不明白為什么，什么錯誤導致的
javax.servlet.ServletException:
Request[/yhb] does not contain handler parameter named 'method'. This may be caused by whitespace in the label text.
解決:form表單中缺少提交方法method=post/get
java.lang.ClassCastException: [Ljava.lang.Object;
at com.carry.service.impl.YhbManagerImpl.loginCheck(YhbManagerImpl.java:44)
javax.servlet.ServletException:
Could not open Hibernate Session for transaction; nested exception is org.hibernate.exception.GenericJDBCException: Cannot
open connection
java.lang.NoClassDefFoundError: org/eclipse/jdt/internal/compiler/ast/ArrayTypeReference
解決辦法：內存溢出，重新啟動(dòng)服務(wù)器
METHOD 傳參數方法找不到，ACTION中，方法的四個(gè)參數順序不能顛倒
tsList(ActionMapping mapping,ActionForm form,
HttpServletRequest request,
HttpServletResponse response)throws Exception
異常：不能連接數據庫（解決： 數據庫連接不上，連接異常，1，檢查網(wǎng)絡(luò )連接，2，檢查是否有連接驅動(dòng)，）
Could not obtain connection metadata
org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory
(Io 異常: Connection refused(DESCRIPTION=(TMP=)(VSNNUM=150999297)(ERR=12505)(ERROR_STACK=(ERROR=(CODE=12505)(EMFI=4)))))
連接拒絕
[SettingsFactory] Could not obtain connection metadata
org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory
(Io 異常: The Network Adapter could not establish the connection)
網(wǎng)絡(luò )適配器不能建立連接，ORACLE數據庫服務(wù)器沒(méi)有打開(kāi)
java.io.IOException: tmpFile.renameTo(classFile) failed
解決：JSP文件中有不能運行的JAVA代碼！
Unable to find a value for "id" in object of class "java.lang.String" using operator "."
解決：<c:forEach var="fun" items="${listFun}"><c:forEach> 中的items="${listFun}" 錯寫(xiě)為items="listFun"
Illegal use of <when>-style tag without <choose> as its direct parent
"${map.yuanYouPur='yuanYouPur'}" contains invalid expression(s): javax.servlet.jsp.el.ELException: Encountered "=", expected
one of ["}", ".", ">", "gt", "<", "lt", "==", "eq", "<=", "le", ">=", "ge", "!=", "ne", "[", "+", "-", "*", "/", "div", "%",
"mod", "and", "&&", "or", "||", "?"]
解決：JSTL語(yǔ)言表達使用錯誤！
The "." operator was supplied with an index value of type "java.lang.String" to be applied to a List or array, but that value
cannot be converted to an integer.
解決：JSP頁(yè)面中，用‘ ${} ’輸出獲得的對象的屬性，使用錯誤，例如返回LIST數組，其中存的對象是OBJ（頁(yè)面中可以定義變量obj代表一
個(gè)OBJ），取OBJ的屬性AGE，NAME, 應該是${obj.age} ${obj.name}即可獲得OBJ的AGE和NAME屬性值,
檢查在使用${}的地方${obj.age} ${obj.name}是否正確，
異常
不能正常打開(kāi)JSP文件?。?007.08.31） enough of enjoyment and comfort
Unable to create this part due to an internal error. Reason for the failure: Widget is disposed
org.eclipse.swt.SWTException: Widget is disposed
解決方法：
1 到window－preference－general－editors－file associations下看看你的*.html默認打開(kāi)方式是什么。
你改成myeclipse html editor就能打開(kāi)了。
2 問(wèn)題已經(jīng)解決，這應該是MyEclipse5.0M2的一個(gè)bug，8月11號新發(fā)布的版本5.0.1GA已經(jīng)修復了此bug。
14:56:10,765 ERROR [DispatchAction] Dispatch[/proAdd] to method getOnePro returned an exception
java.lang.reflect.InvocationTargetException
Caused by: java.lang.Error: Unresolved compilation problem:
at com.carry.struts.action.ProAddAction.getOnePro(ProAddAction.java:60)
... 34 more
解決：查找API，解釋如下（本錯誤是因為該方法沒(méi)有編譯）
InvocationTargetException 是一種包裝由調用方法或構造方法所拋出異常的經(jīng)過(guò)檢查的異常。
從版本 1.4 開(kāi)始，此異常已經(jīng)更新，符合通用異常鏈機制。“目標異常”是在構造的時(shí)候提供的，
可以通過(guò) getTargetException() 方法訪(fǎng)問(wèn)，這類(lèi)對象目前被認為是導致異常的原因，
可以通過(guò) Throwable.getCause() 方法以及后面提到的“遺留方法”訪(fǎng)問(wèn)它。
該異常問(wèn)題同上！
09:11:22,156 INFO [PropertyMessageResources] Initializing, config='org.apache.struts.actions.LocalStrings', returnNull=true
09:11:22,218 ERROR [DispatchAction] Dispatch[/login] to method tree returned an exception
java.lang.reflect.InvocationTargetException
Caused by: java.lang.Error: Unresolved compilation problem:
Syntax error on token "}", { expected
at com.carry.struts.action.LoginAction.tree(LoginAction.java:60)
... 35 more
