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转： javax.servlet.ServletException: Cannot retrieve mapping for action /companyNews struts-config.xml中没有写相关companyNews的action. ============================================ 在myeclipse 增加一个jar包时候，先打开项目properties,选择java build path --> libraries -->add external JARs 选择到需要的jar包，加入后，发现，他这个包加载的是绝对路径，而我们的项目需要cvs共享，无法 commit到cvs服务器。myeclipse有以下提示信息： 2 build path entries are missing. 解决办法是，关闭myeclipse,用notepad打开项目目录下的 .classpath, 手动修改成相对路径，并且检查，指定的相对路径中是否真正添加了jar包， 启动myeclipse就可以上传新添加的jar包了。 ============================================= 在使用junit/StrutsTest时候，报错： java.lang.UnsupportedClassVersionError: junit/framework/TestListener (Unsupported major.minor version 49.0) 原因是如果是jdk1.4的话，只能使用junit3.8以下版本，如果是使用jdk1.5的话，必须使用junit4.0以上版本。 ========================================================== Cannot find ActionMappings or ActionformBeans collection 原因是：web.xml文件中没有配置struts-config.xml的相关信息。 ============================================================ org.apache.jasper.JasperException: The absolute uri: http://java./jstl/core cannot be resolved in either web.xml or the jar files deployed with this application 缺少jstl的相关jar和web.xml配置 jstl.jar <taglib> <taglib-uri>http://java./jstl/fmt</taglib-uri> <taglib-location>/WEB-INF/fmt.tld</taglib-location> </taglib> <taglib> <taglib-uri>http://java./jstl/fmt-rt</taglib-uri> <taglib-location>/WEB-INF/fmt-rt.tld</taglib-location> </taglib> <taglib> <taglib-uri>http://java./jstl/core</taglib-uri> <taglib-location>/WEB-INF/c.tld</taglib-location> </taglib> <taglib> <taglib-uri>http://java./jstl/core-rt</taglib-uri> <taglib-location>/WEB-INF/c-rt.tld</taglib-location> </taglib> <taglib> <taglib-uri>http://java./jstl/sql</taglib-uri> <taglib-location>/WEB-INF/sql.tld</taglib-location> </taglib> <taglib> <taglib-uri>http://java./jstl/sql-rt</taglib-uri> <taglib-location>/WEB-INF/sql-rt.tld</taglib-location> </taglib> <taglib> <taglib-uri>http://java./jstl/x</taglib-uri> <taglib-location>/WEB-INF/x.tld</taglib-location> </taglib> <taglib> <taglib-uri>http://java./jstl/x-rt</taglib-uri> <taglib-location>/WEB-INF/x-rt.tld</taglib-location> </taglib> ========================================================== Failed to load or instantiate TagLibraryValidator class: org.apache.taglibs.standard.tlv.JstlCoreTLV standard.jar没有放在lib里面 =========================================================== 创建oracle表的时候，使用了，role和comment关键字，建议不要将这两个关键字作为表名和字段名。 建议用toad或plsql developer创建表，这样软件会提示关键字。 ============================================================= [ERROR] XMLHelper - Error parsing XML: XML InputStream(18) Attribute name "column" associated with an element type "key" must be followed by the ‘ = ‘ character. [ERROR] Configuration - Could not configure datastore from input stream <org.dom4j.DocumentException: Error on line 18 of document : Attribute name "column" associated with an element type "key" must be followed by the ‘ = ‘ character. Nested exception: Attribute name "column" associated with an element type "key" must be followed by the ‘ = ‘ character.>org.dom4j.DocumentException: Error on line 18 of document : Attribute name "column" associated with an element type "key" must be followed by the ‘ = ‘ character. Nested exception: Attribute name "column" associated with an element type "key" must be followed by the ‘ = ‘ character. xml 语法错误，key语法中应该类似这样的写法 <key column="id"> ============================================================= hibernate3,对象中一对多的one方，必须写private Set pays=new HashSet();，否则包错java.lang.NullPointerException ， 而hibernate2中private Set pays;却不报错； ============================================================= [DEBUG] AbstractSaveEventListener - generated identifier: 1, using strategy: org.hibernate.id.IncrementGenerator org.hibernate.PropertyValueException: not-null property references a null or transient value: com.xxx.yyy.company at org.hibernate.engine.Nullability.checkNullability(Nullability.java:72) <many to one >中的设置应该设置为not-null="false" ，设置为not-null="true"则报以上错误 ================================================================ org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.xxx.yyy.Company 在save的同时也需要save其他的表，然后再flush() ========================================================================= Parse Fatal Error at line 12 column 1 struts-config.xml文件被修改，语法错误。检查语法。 ======================================== org.hibernate.QueryException: could not resolve property: userid of: com.xxx.yyy.Pay 使用到外键userid的时候，必须使用userinfo.userid方法才能得到。 ========================================= javax.naming.NameNotFoundException: Name hibernate_connection_factory is not bound in this Context 原因：hibernate的数据库映射.xml文件有配置错误，导致hibernate_connection_factory无法绑定数据库。 例如many-to-one设置了以后，仍然在其中设置相冲突的<property>属性。 ========================================== [WARN] RequestProcessor - Unhandled Exception thrown: class java.lang.NullPointerException 必须将使用到的对象new起来。 ============================================ GROUP BY 表达式的查询必须满足如下： select 子句后的每一项必需出现在group by 子句中，除非该项使用了聚集函数。 =========================================== org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.xxx.yyy.Company 要级联保存，多次session.save() ============================================== java.lang.IllegalArgumentException: id to load is required for loading 原因： session.load(Company.class,payForm.getCompanyId()); load()方法第二个参数必须是searlizable,并且必须是和数据库映射类的属性值类型一致，即使强制转换都不行。 ============================================= [INFO] DefaultLoadEventListener - Error performing load command <org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [com.xxx.yyy.Company#0] >org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [com.xxx.yyy.Company#0] 表示你现在查询的对象所关联的对象有问题，一般是因为数据的问题（该对象所关联的对象找不到）,数据的错误，影响了程序正常执行。 ======================================================== eclipse 3.1,myeclipse 4错误 Deployment is out of date due to changes in the underlying project contents . You‘ll need to mannally ‘Redeploy‘ the project to update the deployed archive. 原因 tomcat 中部署的某个文件的拒绝访问影响了部署。 重启后，去除tomcat中部署的文件。重新在eclipse中设置部署。 为什么需要重启？ 因为：google desktop软件正在对我部署的一个300MB大文件进行索引，锁定了这个大文件，我估计google desktop需要对这个文件索引半个小时以上。因此，eclipse无法对过去部署的文件，做先删除后重新部署的工作。 =================================================== ERROR LazyInitializationException:19 - could not initialize proxy - the owning Session was closed org.hibernate.LazyInitializationException: could not initialize proxy - the owning Session was closed 解决办法。 cmpy=(CompanyEdit)ss.load(CompanyEdit.class,companyId1); Hibernate.initialize(cmpy);//强制初始化cmpy,否则ss.close()后,cmpy将消失. ==================================================== javascript错误 行: 56 字符: 45 错误: 未结束的字符串常量 代码: 0 是编码的问题！用ANSI编码另存后就好了。 ==================================================== [WARN] JDBCExceptionReporter - SQL Error: 904, SQLState: 42000 [ERROR] JDBCExceptionReporter - ORA-00904: 无效列名 [INFO] DefaultLoadEventListener - Error performing load command <org.hibernate.exception.SQLGrammarException: could not load an entity: [com.xxx.yyy.Sellinfo#1] >org.hibernate.exception.SQLGrammarException: could not load an entity: [com.xxx.yyy.Sellinfo#1] ***.hbm.xml文件中的某个列名和数据库中的不同。 ======================================================= ConnectionManager - unclosed connection, forgot to call close() on your session? 原因：没有关闭hibernate的session的transaction。或者没有关闭session ======================================================= [WARN] SellCommentDAO - org.hibernate.ObjectDeletedException: deleted object would be re-saved by cascade (remove deleted object from associations): [com.xxx.yyy.SellComment#7] 原因：父亲对象（one方）设置cascade="save-update" 时，直接删除子对象时，会报错， 处理方法：save信息需要级联操作，delete时候也要用相同的原理。 SellComment sellComment=new SellComment(); sellComment = (SellComment)session.load(SellComment.class,sellCommentId);//获取儿子对象 Long sellInfoId=sellComment.getSellInfo().getSellId();//获取父亲id SellInfo sellinfo=(SellInfo)session.load(SellInfo.class,sellInfoId);//获取父亲对象 sellInfo.getSellComments().remove(sellComment);//断绝父子关系 sellComment.setSellInfo(null);//断绝子父关系 session.delete(sellComment);//删除儿子 session.flush(); |
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