Data Validation and Formatting Operations in EasyExcel Framework in the EasyExcel framework (

The EasyExcel framework is a powerful Java open source framework to simplify the read and write operation of the Excel file.It provides rich functions and flexible interfaces, making data verification and formatting operations on the Excel file.This article will introduce the data verification and formatting operations in the EasyExcel framework, and provide the corresponding Java code example. 1. Data Validation Data verification is a commonly used operation to verify whether the data in the Excel table meets specific requirements.In the EasyExcel framework, you can specify the data verification rules of each field by using the `@Excelproperty` annotation.The following is an example code: public class User { @ExcelProperty(value = "姓名", validator = NameValidator.class) private String name; @ExcelProperty(value = "年龄", validator = AgeValidator.class) private Integer age; // omit the getter and setter method } public class NameValidator implements ConstraintValidator<String> { @Override public boolean isValid(String value) { // Write the verification rules here and return to the verification results } } public class AgeValidator implements ConstraintValidator<Integer> { @Override public boolean isValid(Integer value) { // Write the verification rules here and return to the verification results } } public class DataValidationExample { public static void main(String[] args) { List<User> userList = new ArrayList<>(); // Add user data to UserList // Create an example of writing Excel ExcelWriter excelWriter = EasyExcel.write("example.xlsx").build(); // Write the data to the Excel file WriteSheet writesheet = EasyExcel.writersheet ("User Information") .build (); excelWriter.write(userList, writeSheet); // Close the resource excelWriter.finish(); } } In the above examples, the `Name` and Age` fields in the` User` class use the `@ExcelProperty` annotation, respectively.The `nameValidator` and` Agevalidator` classes implement the `ConstraintValidator` interface, which is used to check whether the value of the corresponding field meets the requirements.In the `ISVALID` method, you can write specific verification rules and return the verification results. 2. Formatting Operations The formatting operation is to format the data in the Excel table in accordance with specific rules to meet business needs.The EasyExcel framework provides a flexible interface. You can implement the formatting operation by setting the `converter` attribute of`@ExcelProperty`.The following is an example code: public class User { @ExcelProperty(value = "生日", converter = DateConverter.class) private Date birthday; // omit the getter and setter method } public class DateConverter implements Converter<Date> { @Override public Class<Date> supportJavaTypeKey() { return Date.class; } @Override public CellDataTypeEnum supportExcelTypeKey() { return CellDataTypeEnum.DATE; } @Override public Date convertToJavaData(CellData<?> cellData, ExcelContentProperty contentProperty, GlobalConfiguration configuration) { // Written the data formatting rules here, and return the formatted date object } @Override public CellData<?> convertToExcelData(Date value, ExcelContentProperty contentProperty, GlobalConfiguration configuration) { // Written the data formatting rules here, and return the formatted Excel data object } } public class FormattingExample { public static void main(String[] args) { List<User> userList = new ArrayList<>(); // Add user data to UserList // Create an example of writing Excel ExcelWriter excelWriter = EasyExcel.write("example.xlsx").build(); // Write the data to the Excel file WriteSheet writesheet = EasyExcel.writersheet ("User Information") .build (); excelWriter.write(userList, writeSheet); // Close the resource excelWriter.finish(); } } In the above example, the `@ExcelProperty` Annotation of the` BIRTHDAY` field in the `user` class, which specifies the formatting class of the field.The `DateConverter` class implements the` converter` interface to format the `date` object in Java into the date format in Excel, and convert the date format in Excel into the` date` object in Java.In the `Converttojavadata` and` Converttoexceldata` methods, you can write specific data formatting rules and return the formatted object. Through the data verification and formatting operation of the EasyExcel framework, it can easily verify and format the data in the Excel file to meet different business needs.Using these functions can improve the efficiency and accuracy during the Excel file processing process, and reduce the possibility of errors.