Master the abnormal processing and error processing strategy in Spring Web Flow

Master the abnormal processing and error processing strategy in Spring Web Flow Spring Web Flow is a framework for developing a process -based web application. It provides powerful abnormal processing and error processing strategies in order to better handle abnormalities and errors in the application.This article will introduce the relevant concepts of abnormal processing and error processing in Spring Web Flow and how to implement them in applications. 1. Abnormal processing strategy 1. Global abnormal processor: You can use a global abnormal processor to deal with the possible abnormalities in the entire application.By defining the <Global-EXCEPTION-Handler> element and specify an abnormal processing class by defining the <Global-EXCEPTION-Handler> element, it can capture and deal with the abnormalities thrown in the process. Example code: public class GlobalExceptionHandler implements FlowExecutionExceptionHandler { @Override public boolean canHandle(FlowExecutionException exception) { Return true; // All abnormalities are handled by the processor } @Override public void handle(FlowExecutionException exception, RequestControlContext context) { // Treatment of abnormal logic } } Add the following in the Web Flow configuration file: <flow-executor> <exception-handlers> <global-exception-handler exception-handler="globalExceptionHandler" /> </exception-handlers> </flow-executor> 2. Local abnormal processor: In addition to global abnormal processors, it can also define local anomalous processors for each process.By defining the <Exception-Handler> element and specifying an abnormal processing class in the process definition file, the abnormal process can be captured within a specific process range. Example code: public class LocalExceptionHandler implements FlowExecutionExceptionHandler { @Override public boolean canHandle(FlowExecutionException exception) { Return true; // All abnormalities are handled by the processor } @Override public void handle(FlowExecutionException exception, RequestControlContext context) { // Treatment of abnormal logic } } Add the following in the process definition file: <flow> <exception-handler exception-handler="localExceptionHandler" /> </flow> Second, error handling strategy 1. Form error processor: When the user has an error when filling in the form, you can use a form error processor to handle these errors.It can be achieved by defining the <On-Ere> element and error processing class in the <View-State> element in the process definition file. Example code: public class FormErrorHandler implements ErrorHandler { @Override public void handleError(ClientValidationErrors errors, HttpServletRequest request, HttpServletResponse response) { // Treatment the form of the form error logic } } Add the following in the <View-State> element in the process definition file: <on-error> <error-handler bean="formErrorHandler" /> </on-error> 2. Process error processor: When an error occurs during the process of the process, the process error processor can be used to deal with these errors.It can be achieved by defining error processing classes in the <Exception-Handler> element in the process definition file. Example code: public class FlowErrorHandler implements FlowExecutionExceptionHandler { @Override public boolean canHandle(FlowExecutionException exception) { Return true; // All abnormalities are handled by the processor } @Override public void handle(FlowExecutionException exception, RequestControlContext context) { // Process process error logic } } Add the following in the process definition file: <flow> <exception-handler exception-handler="flowErrorHandler" /> </flow> By mastering abnormal processing and error processing strategies in Spring Web Flow, it can better handle abnormalities and errors that may occur in the application, and improve the stability and fault tolerance of the application.