Arithmetic exception class: ArithmeticExecption
Null pointer exception class: NullPointerException
Type cast exception: ClassCastException
Array negative subscript exception: NegativeArrayException
Array index out of bounds exception: ArrayIndexOutOfBoundsException
Exception that violates security principles: SecurityException
End of file exception: EOFException
File not found exception: FileNotFoundException
String to number exception: NumberFormatException
Operation database exception: SQLException
Input and output exception: IOException
Method not found exception: NoSuchMethodException
java.lang.AbstractMethodError
Abstract method error. Thrown when the application attempts to call an abstract method.
java.lang.AssertionError
The assertion is wrong. Used to indicate an assertion failure.
java.lang.ClassCircularityError
Class circular dependency error. When initializing a class, this exception is thrown if a circular dependency between classes is detected.
java.lang.ClassFormatError
Class format error. Thrown when the Java virtual machine attempts to read a Java class from a file and detects that the contents of the file do not conform to a valid format for the class.
java.lang.Error
mistake. Is the base class for all errors and is used to identify serious program operation problems. These problems usually describe some unusual situation that should not be caught by the application.
java.lang.ExceptionInInitializerError
Initialization program error. Thrown when an exception occurs during the execution of a class's static initializer. Static initializer refers to the static statement segment directly included in the class.
java.lang.IllegalAccessError
Illegal access error. This exception is thrown when an application attempts to access or modify a field (Field) of a class or call its method, but violates the visibility declaration of the field or method.
java.lang.IncompatibleClassChangeError
Incompatible class change error. This exception is thrown when an incompatible change occurs in the class definition on which the method being executed depends. Generally, this error is easily caused when the declaration definition of some classes in the application is modified without recompiling the entire application and then running it directly.
java.lang.InstantiationError
Instantiation error. This exception is thrown when an application attempts to construct an abstract class or interface through Java's new operator.
java.lang.InternalError
Internal error. Used to indicate that an internal error has occurred in the Java virtual machine.
java.lang.LinkageError
Link error. This error and all its subclasses indicate that a class depends on other classes. After the class is compiled, the dependent class changes its class definition without recompiling all classes, thus causing the error condition.
java.lang.NoClassDefFoundError
Class definition not found error. This error is thrown when the Java virtual machine or class loader attempts to instantiate a class and cannot find the definition of the class.
java.lang.NoSuchFieldError
There is no error in the domain. This error is thrown when an application attempts to access or modify a field of a class that does not have a definition for that field.
java.lang.NoSuchMethodError
There is no error in the method. This error is thrown when the application attempts to call a method of a class that does not have a definition for the method.
java.lang.OutOfMemoryError
Out of memory error. This error is thrown when the available memory is insufficient for the Java virtual machine to allocate an object.
java.lang.StackOverflowError
Stack overflow error. This error is thrown when an application makes recursive calls too deep and causes a stack overflow.
java.lang.ThreadDeath
The thread ends. This error is thrown when the stop method of the Thread class is called to indicate the end of the thread.
java.lang.UnknownError
Unknown error. Used to indicate that an unknown serious error has occurred in the Java virtual machine.
java.lang.UnsatisfiedLinkError
Unsatisfied link error. Thrown when the Java virtual machine does not find a native language definition of a class that declares a native method.
java.lang.UnsupportedClassVersionError
Unsupported class version error. This error is thrown when the Java virtual machine tries to read a certain class file, but finds that the major and minor version numbers of the file are not supported by the current Java virtual machine.
java.lang.VerifyError
Validation error. This error is thrown when the validator detects an internal incompatibility or security issue in a class file.
java.lang.VirtualMachineError
Virtual machine error. Used to indicate a situation where a virtual machine has been destroyed or has insufficient resources to continue operations.
java.lang.ArithmeticException
Arithmetic condition exception. For example: integer division by zero, etc.
java.lang.ArrayIndexOutOfBoundsException
Array index out of bounds exception. Thrown when the index into the array is negative or greater than or equal to the array size.
java.lang.ArrayStoreException
Array storage exception. Thrown when an object of non-array declared type is stored in an array.
java.lang.ClassCastException
Class modeling anomaly. Suppose there are classes A and B (A is not the parent class or subclass of B), and O is an instance of A, then this exception is thrown when O is forced to be constructed as an instance of class B. This exception is often called a cast exception.
java.lang.ClassNotFoundException
Class exception not found. This exception is thrown when the application attempts to construct a class based on a class name in string form, but cannot find the class file with the corresponding name after traversing the CLASSPAH.
java.lang.CloneNotSupportedException
Clone exceptions are not supported. When the Cloneable interface is not implemented or the clone method is not supported, calling its clone() method will throw this exception.
java.lang.EnumConstantNotPresentException
There are no exceptions for enumeration constants. This exception is thrown when an application attempts to access an enumeration object by name and enumeration type, but the enumeration object does not contain a constant.
java.lang.Exception
Root exception. Used to describe the situation the application wishes to capture.
java.lang.IllegalAccessException
Illegal access exception. This exception is thrown when the application attempts to create an instance of a class, access the class properties, or call the class methods through reflection, and the definition of the class, property, method, or constructor cannot be accessed at that time.
java.lang.IllegalMonitorStateException
Illegal monitoring status is abnormal. This exception is thrown when a thread attempts to wait for the monitor of an object (O) that it does not own or notifies other threads to wait for the monitor of the object (O).
java.lang.IllegalStateException
Illegal status abnormality. This exception is thrown when a method is called in the Java environment and application before it is in a legal calling state.
java.lang.IllegalThreadStateException
Illegal thread status exception. When the county is not in the legal calling state of a certain method and the method is called, an exception is thrown.
java.lang.IndexOutOfBoundsException
Index out of bounds exception. This exception is thrown when the index value of a sequence is less than 0 or greater than or equal to the sequence size.
java.lang.InstantiationException
Instantiation exception. This exception is thrown when trying to create an instance of a class through the newInstance() method, and the class is an abstract class or interface.
java.lang.InterruptedException
Aborted exception. This exception is thrown when a thread is in a long-term waiting, sleeping or other suspended state, and other threads terminate the thread through Thread's interrupt method.
java.lang.NegativeArraySizeException
Negative array size exception. This exception is thrown when an array is created with a negative size value.
java.lang.NoSuchFieldException
There is no exception in the attribute. This exception is thrown when accessing a non-existent property of a class.
java.lang.NoSuchMethodException
There is no exception in the method. This exception is thrown when accessing a non-existent method of a class.
java.lang.NullPointerException
Null pointer exception. This exception is thrown when the application attempts to use null where an object is required. For example: calling the instance method of the null object, accessing the properties of the null object, calculating the length of the null object, using the throw statement to throw null, etc.
java.lang.NumberFormatException
The number format is abnormal. This exception is thrown when an attempt is made to convert a String to a specified numeric type and the string does not meet the format required by the numeric type.
java.lang.RuntimeException
Runtime exception. Is the parent class for all exceptions that can be thrown during normal operation of the Java virtual machine.
java.lang.SecurityException
Security exception. Exception thrown by the security manager to indicate a security violation.
java.lang.StringIndexOutOfBoundsException
String index out of bounds exception. This exception is thrown when a character in a string is accessed using an index value that is less than 0 or greater than or equal to the sequence size.
java.lang.TypeNotPresentException
There is no exception for the type. This exception is thrown when an application attempts to access a type as a string representation of the type name, but the type cannot be found based on the given name. The difference between this exception and ClassNotFoundException is that this exception is an unchecked (unchecked) exception, while ClassNotFoundException is a checked (checked) exception.
java.lang.UnsupportedOperationException
Unsupported method exception. Exception indicating that the requested method is not supported.
abnormal
javax.servlet.jsp.JspException: Cannot retrieve mapping for action /Login (/Login is your action name)
Possible reasons
The action is not defined in struts-config.xml, or no matching action is found. For example, use <html:form action="Login.do" in the JSP file. Submit the form to Login.do for processing. If the above exception occurs, Please check the definition part in struts-config.xml. Sometimes there may be wrong characters or some irregularities. You can use the strutsconsole tool to check.
-