how to use exceptions java

Exceptions in Java are divided into 2 types:1:JVM exceptions, such exceptions or errors are thrown by the JVM. With exclusivity or the most logical2: Program exceptions, these exceptions are thrown by the application or API progra

How to handle exceptions in JAVA? What are the meanings of the keywords throws, throw, try, catch, and finally? Can an exception be thrown in the try block ?, Java uses object-oriented methods to handle exceptions, classify various exceptions, and provides a goodInterface.I

Package namespace; import Java. io. *; public class iotest {public static void main (string Arg []) {filewriter writer = NULL; // The reference is defined outside try, in this way, you can call try {writer = new filewriter ("F: \ java.txt") in the non-existing code block; // try writer on the code that causes the exception. write ("ABC");} catch (ioexception ex) {system. out. println (ex. tostring ();} finally // do not forget to release the resource

There are a number of methods in the socket class that use throws to throw exceptions when declared, all of which are subclasses of IOException. SocketException is the most common method in the socket class, and there are seven exceptions that can be thrown by the method of the socket class. These exceptions are shown

variable-subscript) calls are often wrong, there is also a case, the length of the defined array in the program is determined by certain methods, is not declared beforehand, it is better to look at the array length, To prevent this exception from occurring.5. Java.lang.IllegalAccessExceptionThis exception is interpreted as "no access", which occurs when the application is calling a class, but the current method does not have access to the class. You should pay attention to this exception in cas

) {//Compare Arr[x] value is greater than Max8max = arr[x];//conditional, assign the value of Arr[x] to Max9 }Ten } OneSystem.out.println ("max=" + max);//Print Maximum value A } - } -Result: The maximum value is 9Array exception array out of bounds exceptionwhen accessing the elements of an array, the index cannot exceed this Array of range, or the program will errorNull pointer exceptionWhen you use a variable to reference an

-subscript) calls are often wrong, there is also a case, the length of the array defined in the program is determined by certain methods, is not declared beforehand, it is better to look at the array length, To prevent this exception from occurring.5. Java.lang.illegalargumentexceptionThe explanation of this exception is "parameter error of the method", and many methods in the J2ME class library can cause such errors in some cases, such as the volume parameter in the volume adjustment method, if

Tutorial Before trying to catch a try/catch exception, you must first talk about the Exceptions exception. An exception will be thrown every time an error occurs. Example: ArrayIndexOutOfBounds array out-of-bounds error will be thrown when the index does not exist in the array (e. g: Try to get arr [5], but the maximum arr array can only get arr [4]). An error in ArithmeticError calculation will be thrown when an invalid number operation is performed

Partitioning and exceptions for Java memory regionsRun-time data regionThe JVM divides the memory into a number of different data regions when running Java programs.open Baidu app to see more beautiful picturesProgram counterThread Private. Can be thought of as the line number indicator of the byte code executed by the current thread, and the bytecode interpreter

may occurCatch: A code that captures such exceptions and processesThe TRY statement block does not have an exception and the catch statement block is not printedExceptin: Checking for exceptionsRuntimeException: Run-time exceptionError: Fault is not an exception at allThrow: Throws an exception, throws an exception manuallyTerows: Declaring an exception, throwingThe Finaly keyword is used to create a block of code right in the try block, and finaly a

() method to print, to the console, the sequence of nested method calls this was Awaiting completion when the exception was thrown.3.If A superclass method declares a throws clause, the overriding subclass method does not having to declare a throws clause . However,if It does declare a throws clause, the clause must not include the names of exception classes that is not also I Ncluded in the superclass method ' s throws clause.4.A checked Exception class name does not need to appear in A throws

, negativearraysizeexceptionCreate an array error exception with a negative size, for example int[] arr = new Int[10];int i = arr[-1];12, SecurityExceptionSecurity exceptions, such as: Android permissions exception, program prompts to run Java missing requited Permissions manifest attribute in main jar, etc.13, EofexceptionFile has ended exception14. FileNotFoundExceptionFile not found exception15. SQLExcep

MVC filter Use Case: uniformly handling exceptions by streamlining code1.MVC FilterThe idea of using attribute from Method 2 can easily think of the MVC filter, using the filter's interception function to implement exception handling in accordance with the AOP idea, and decouple the module from the logic layer. About the MVC filter introduction, many articles on the internet, recommended "MVC filter detaile

Before you learn to handle exceptions in a program, it's good to see what happens if you don't deal with them. The following applet includes an expression deliberately causing the error to be removed by 0.1 class Exc0 {2 Public Static void Main (String args[]) {3 int d = 0; 4 int a = n/ D; 5 }6 }When the Java runtime system checks for a condition that is removed by 0, it constructs

Most recently, there are a variety of exception bugs that are encountered during the writing of a project. It takes a lot of time to make a bug every time, so today it's time to sum up some common anomalies for your reference. There is no place to say is not very right, need to modify the can DMS me or comment. First of all, we should be traced to the source code for the exception, so that we understand the deeper point. All exceptions are inherited