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PC running slow?
Today’s tutorial is written to help you if you get a jsp exception error. g.Exceptions are thrown in JSPs when an error in the code can be caused by a developer, or an internal error can be caused by the system. Exception handling in JSP is literally the same as in Java, where my spouse and I handle exceptions using Try Catch blocks. In JSP, unlike Java, there are exceptions when there is no error in the human code.
g.
In this chapter. We will discuss an easy way to handle exceptions in JSP. Writing JSP code can lead to coding errors that can appear anywhere in the code. The following errors may appear in your JSP code:
Exceptions Checked
What is JSP exception?
The exception is usually an object that is run at runtime. Exception handling is a type of process used to handle run-time errors. There are two ways in JSP to successfully handle exceptions: byusing the errorPage attributes and simply using the isErrorPage attributes of the page directive. Depending on the depth of
A checked omission is an exception that is sometimes a user error or problem and therefore cannot be predicted by the programmer. For example, if the file needs to be opened further, but the file cannot be found, an exception is thrown. These exceptions cannot be ignored at compile time only.
Execution Exceptions
The runtime is an exception, an exception that this programmer could probably have avoided. Unlike checked conditions, runtime exceptions are ignored at some point during compilation.
Error
These are hardly any exceptions, but rather problems that arise outside the area of responsibility of the user or program ammista. Errors are usually ignored in your code because you can rarely do something about a serious error. For example, an overflow error occurs. Whether they were ignored at compile time at the time.
We will talk more about how to handle uptime exceptions / errors in your jsp code.
Use Object
Throwing an exception object is an event of a Throwable subclass (for example, java.lang. NullPointerException) and is only available in error messages and articles. The following table lists the required methods available in the Throwable class.
| No. | Methods and Description |
|---|---|
| 1 |
public string getMessage () Returns a detailed description of the exception that was thrown. This message is initialized in the Throwable constructor. |
| 2 |
get one-time public reason () Gets the reason for the exception as a Throwable object. |
| 3 |
public string toString () Returns the name of the field associated with the getMessage () result. |
| 4 |
public printStackTrace () Prints an empty result toString () with some stack trace to System.err, product stream with error. |
| 5 |
public StackTraceElement [] getStackTrace () Returns an array containing each element of the trace stack. The element at index 0 represents the largest element in the call stack, and the constant element in the array represents the most important method at the bottom of the call stack. |
| 6 |
one-time public fillInStackTrace () Populates the trace stack for this Throwable Object with the current stack order and adds any previous stack information to the trace. |
The
JSP gives you the ability to specify a page error directly for each JSP. Every time the page throws an exception, the JSP will automatically call the error page in the container.
Below is usually an example of specifying an error website for the main a.jsp file. To create some kind of error page, use the <% @ page operator, which implies errorPage "xxx"%>.
We are now writing the ShowError.jsp JSP error handling error, which is listed below. Note that most of the error handling page contains a page with instructions <% @ isErrorPage = "true"%>. This statement causes the JSP compiler to generate the appropriate exception instance variable.
Operations …
Sorry, this is a deliberate mistake.
Exception trace should be here: Stack
<% exception.printStackTrace (response.getWriter ()); %>
When you access the main.jsp file, you can get output similar to the following:
Use JSTL For Tag Cloud Error Page
With JSTL tags, you can write a page withShowError.jsp error. This page has almost the same logic as the example above, with improved design and more information.
Operations …
$ trace