在 Java 语言中，程序运行出错被称为出现异常（Exception）。 异常是程序运行过程中发生的事件，该事件可以中断程序指令的 正常执行流程。 O Java 异常分为两大类 1. 错误（Error）是指 JVM 系统内部错误、资源耗尽等严重情 况。 2. 违例（Exception）则是指其他因编程错误或偶然的外在因 素导致的一般性问题，例如对负数开平方根、空指针访问、 试图读取不存在的文件以及网络连接中断等。 在 Java 语言中，程序运行出错被称为出现异常（Exception）。 异常是程序运行过程中发生的事件，该事件可以中断程序指令的 正常执行流程。 O Java 异常分为两大类 1. 错误（Error）是指 JVM 系统内部错误、资源耗尽等严重情 况。 2. 违例（Exception）则是指其他因编程错误或偶然的外在因 素导致的一般性问题，例如对负数开平方根、空指针访问、 试图读取不存在的文件以及网络连接中断等。 成一个相应的异常类对象，然后再将它交给运行时系统。 ▶ 运行时系统再寻找相应的代码来处理这一异常。如果 Java 运行时系统找不到可以处理异常的代码，则运行时系统将终 止，相应的 Java 程序也将退出。 ▶ 程序员通常对错误（Error）无能为力，因而一般只处理违 例 (Exception)。 大纲 异常的概念及分类 Java 异常处理机制 Java 异常处理机制 ▶ Java 程序执行过程中如出现异常，系统会监测到并自动生

JdkDynamicAopProxy's "Method.setAccessible" handling to avoid unnecessary calls * Cglib2AopProxy throws AopConfigException instead of AspectException, for better root cause handling * CGLIB proxies handle "hashCode" specific fashion as well Package org.springframework.jmx * MBeanExporter only logs a warning (no error) when an MBean does not exist anymore when trying to unregister * MBeanExporter's MBean autodetection Package org.springframework.validation * clarified that "Errors.reject" always registers a global error for the entire target object * "Errors.rejectValue" now accepts an empty field name to indicate the

SQLErrorCodesFactory always loads its "sql-error-codes.xml" files from Spring's class loader (-> static singleton) * added "transientDataAccessResourceCodes" category to "sql-error-codes.xml", with default codes Sybase * SQLErrorCodeSQLExceptionTranslator applies default SQLExceptionSubclassTranslator after error code translation only * SQLErrorCodeSQLExceptionTranslator is able to work without fallback SQLState leading "/../" part as well (as accepted by most servlet containers) * DispatcherServlet removes error-view-driven servlet request attributes after rendering (for Tomcat compatibility) * exposed "getParamName()"

SQLErrorCodesFactory always loads its "sql-error-codes.xml" files from Spring's class loader (-> static singleton) * added "transientDataAccessResourceCodes" category to "sql-error-codes.xml", with default codes Sybase * SQLErrorCodeSQLExceptionTranslator applies default SQLExceptionSubclassTranslator after error code translation only * SQLErrorCodeSQLExceptionTranslator is able to work without fallback SQLState leading "/../" part as well (as accepted by most servlet containers) * DispatcherServlet removes error-view-driven servlet request attributes after rendering (for Tomcat compatibility) * exposed "getParamName()"

building correct relative paths for them Package org.springframework.jdbc * added further default SQL error codes for DB2 and HSQLDB * refined NativeJdbcExtractorAdapter to retry with DatabaseMetaData Connection method public * improved JdbcTemplate's logging of ignored SQLWarnings, including SQL state and error code in the log output * JdbcTemplate's "queryForObject"/"queryForInt"/etc methods correctly detect cannot" message at debug level (not warn) * TransactionInterceptor logs application exception at error level if commit throws an exception Package org.springframework.util * fixed CollectionsUtils's "hasUniqueObject"

out MessageSourceSupport base class from AbstractMessageSource, providing common MessageFormat handling * DelegatingMessageSource resolves message arguments in default messages even if there is no parent CodebaseAwareObjectInputStream in RMI support * re-enabled PathMatchingResourcePatternResolver's JarURLConnection handling (accidentally disabled in 2.5.4) Package org.springframework.ejb * "jee:local/remote-slsb" accepts SqlXmlHandler abstraction (for the XML support in the Advanced Pack for Oracle Database) * added further SQL error code mapping for MS SQL Server Package org.springframework.jms * SingleConnectionFactory and Tra

"messageSource" bean even through an alias Package org.springframework.jdbc * added further default SQL error codes for MS SQL, MySQL, and Oracle * OracleLobHandler lazily initializes Oracle driver classes, always LocalSessionFactoryBean offers protected "executeSchemaStatement" method for overriding the failure handling * added "configLocations" property to LocalSessionFactoryBean for Hibernate3, allowing to load NestedServletException wherever a root cause gets wrapped by a ServletException (for nicer root cause handling) * "contextConfigLocation" params in "web.xml" support "${...}" style placeholders for system properties

to perform auto-detachment of the result * changed TopLink ServerSessionFactory's managed client handling to proxy-based, in base class AbstractSessionFactory * added support for TopLink SessionBroker springframework.validation * BindException uses canonical bean property paths for error registration, allowing any map key syntax for error access * added convenience constructors to DataBinder, WebDataBinder and ptor Package org.springframework.web * introduced NestedServletException for proper root cause handling, extended by Spring's MultipartException * refined ServletContextResourcePatternResolver to handle