The Streaming Excel Reader framework tutorials for EXCEL data streaming in the classic Java class library
The Streaming Excel Reader framework tutorials for EXCEL data streaming in the classic Java class library
introduce:
Excel is a widely used electronic table application. Many business scenarios need to process a large amount of Excel data. Traditional reading methods may cause memory overflow or performance problems when dealing with large Excel files.To solve this problem, the Streaming Excel Reader framework came into being.This framework uses a streaming reading method, which can efficiently handle large Excel files without loading the entire file into memory.
step:
1. Import dependency library
In the pom.xml file of the project, add the dependencies of Apache Poi and EasyExcel.
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>easyexcel</artifactId>
<version>2.2.11</version>
</dependency>
2. Create an excel file reader
Create an ExcelReader class to read the Excel data stream and analyze the data.
import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.read.listener.ReadListener;
public class ExcelReader {
public <T> void read(InputStream inputStream, Class<T> clazz, ReadListener<T> listener) {
EasyExcel.read(inputStream)
.head(clazz)
.registerReadListener(listener)
.sheet()
.doRead();
}
}
3. Create data objects
Create a data object for data in instantiated Excel.The attribute of the object may correspond to the column in the Excel table.
public class User {
private String name;
private int age;
// getter and setter
}
4. Write data reading and obtaining listening device
Create a data reading obtaining listener for processing data in Excel.The listener needs to inherit the ReadListener interface and rewrite the corresponding method.
import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
public class UserListener extends AnalysisEventListener<User> {
@Override
public void invoke(User data, AnalysisContext context) {
// Data processing
}
@Override
public void doAfterAllAnalysed(AnalysisContext context) {
// The operation of the data after reading
}
}
5. Use Streaming Excel Reader framework to read Excel data stream
In the main code, instantiate ExcelReader and UserListener, and call the Read method to read the Excel data stream.
public class Main {
public static void main(String[] args) {
File file = new File("path/to/excel/file.xlsx");
InputStream inputStream;
try {
inputStream = new FileInputStream(file);
ExcelReader excelReader = new ExcelReader();
UserListener listener = new UserListener();
excelReader.read(inputStream, User.class, listener);
} catch (IOException e) {
e.printStackTrace();
}
}
}
Summarize:
The Streaming Excel Reader framework provides an efficient way to handle large Excel files. By using a streaming reading method, it avoids memory overflow and performance problems.This article introduces how to use the Streaming Excel Reader framework to read the Excel data stream and provide the corresponding Java code example.Using this framework can easily process a large amount of Excel data to improve the efficiency of data processing.
