Use JXLS Reader to achieve the best practice of data introduction and exporting
Use JXLS Reader to achieve the best practice of data introduction and exporting
JXLS is an open source library that simplifies Excel's import and export in Java.It provides convenient API and tools, enabling developers to read data easily from the excel file and write the data into the Excel file.This article will introduce the best practice using JXLS Reader to implement data import and export, and provide some Java code examples.
1. Data import
1. Add JXLS dependencies
First, you need to add the JXLS library to your project dependence.You can add the following dependencies in Maven or Gradle:
Maven：
<dependency>
<groupId>org.jxls</groupId>
<artifactId>jxls-reader</artifactId>
<version>2.9.0</version>
</dependency>
Gradle：
implementation 'org.jxls:jxls-reader:2.9.0'
2. Create an excel template
In order to read data from the Excel file, you need to create an Excel template.This template will contain the structure and format of the data you want to import.You can use Microsoft Excel or other available electronic meter editing tools to create this template.
3. Write data import code
Reading data with JXLS Reader is very simple.You only need to specify the SHEET name where the Excel file and data you want to read, and load it to an `InputStream` object.You can then read data from the API provided by JXLS from the `InputStream`.
The following is a simple example. Demonstrate how to read an Excel file containing names and age:
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.jxls.reader.ReaderBuilder;
import org.jxls.reader.XLSReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class ExcelReaderExample {
public static void main(String[] args) throws IOException, InvalidFormatException {
String templatePath = "path/to/your/template.xls";
String sheetName = "Sheet1";
try (InputStream input = new FileInputStream(templatePath)) {
XLSReader reader = ReaderBuilder.buildFromXML(new FileInputStream("path/to/your/mapping.xml"));
List<Map<String, String>> data = new ArrayList<>();
Map<String, Object> context = new HashMap<>();
context.put("data", data);
reader.read(input, context);
// Here you can process or save the read data to the database, etc.
for (Map<String, String> row : data) {
String name = row.get("name");
String age = row.get("age");
// Data processing...
}
}
}
}
In the above example, we created a `xlsreader` object through the` ReaderBuilder`.Then, we pass the path of the Excel template and the sheet name to the `Read` method of the` Reader`.JXLS reads the data in the template and transmits it as an object of the `data` object.You can use this data in the `Context` for follow -up processing.
Note: In the above example, we use a mapping file called `mapping.xml`.This file is used to specify the mapping relationship of each column in Excel templates.You can create a mapping file as needed and use it in the `Readerbuilder`.
Data export
1. Create a data model
Before the data exports, you need to create a data model.The data model can be a POJO class or a map.
2. Add JXLS dependencies
Similarly, you need to add the JXLS library to your project dependence.Please refer to the dependency code provided in the previous steps.
3. Write data export code
It is also very simple to export data with JXLS Reader.You only need to create a `Workbook` object, and use the API provided by JXLS to write the data into Workbook.You can then save workbook as Excel file.
Below is a simple example, demonstrate how to export the data to the Excel file:
import org.apache.poi.ss.usermodel.Workbook;
import org.jxls.common.Context;
import org.jxls.util.JxlsHelper;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class ExcelWriterExample {
public static void main(String[] args) throws IOException {
List<Person> data = new ArrayList<>();
data.add(new Person("Alice", 25));
data.add(new Person("Bob", 30));
try (FileOutputStream output = new FileOutputStream("path/to/your/output.xls")) {
try (InputStream template = new FileInputStream("path/to/your/template.xls")) {
Context context = new Context();
context.putVar("data", data);
JxlsHelper.getInstance().processTemplate(template, output, context);
}
}
}
}
In the above example, we created a `Context` object and put the data into it.Then, we use the `ProcessSessterMPlate` method of` jxlshelper` to write the data into the Excel file.This method needs to provide the `InputStream` object of Excel template and the` FileoutPutstream` object of the output file.
According to your needs, you can use more JXLS functions and APIs to define export behaviors.You can find more detailed information and sample code on the use of JXLS to implement data import and export in the official JXLS document.
The above is the best practice of using JXLS Reader to implement data import and export.With the JXLS library, you can easily read data from the Excel file and export data to the Excel file, which improves the efficiency and accuracy of data processing.
I hope this article will help you, I wish you use JXLS Reader to successfully achieve data import and export!
