Streaming Excel Reader framework application example and source code analysis
Streaming Excel Reader framework application example and source code analysis
Streaming Excel Reader is a Java framework for analyzing large Excel files. It has the ability to manage and read data quickly.This article will introduce the application example of the Streaming Excel Reader framework and provide the corresponding Java source code analysis.
Example:
Suppose we have a large Excel file, which contains information such as employee's work number, name, age, and wage.We want to use the Streaming Excel Reader framework to read this Excel file and display the employee's information on the console.
Code example:
First, we need to introduce the dependencies of Streaming Excel Reader in the project.
<dependency>
<groupId>com.monitorjbl</groupId>
<artifactId>xlsx-streamer</artifactId>
<version>2.1.0</version>
</dependency>
Next, we define an Employee class to represent the employee's information.
public class Employee {
private int id;
private String name;
private int age;
private double salary;
// omit the creation function and getter/setter method
}
We then write the code to read the excel file.
import com.monitorjbl.xlsx.StreamingReader;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
public class ExcelReader {
public static void main(String[] args) throws IOException {
try (InputStream is = new FileInputStream("employees.xlsx")) {
// Create StreamingReader objects
StreamingReader reader = StreamingReader.builder()
.rowCacheSize(100)
.bufferSize(4096)
.open(is);
for (Row row : reader) {
// Read the line data and create an Employee object
Employee employee = new Employee();
Cell cell = row.getCell(0);
employee.setId((int) cell.getNumericCellValue());
cell = row.getCell(1);
employee.setName(cell.getStringCellValue());
cell = row.getCell(2);
employee.setAge((int) cell.getNumericCellValue());
cell = row.getCell(3);
employee.setSalary(cell.getNumericCellValue());
// Print employee information
System.out.println(employee);
}
}
}
}
Source code analysis:
The main part of the above example code is the main method of the ExcelReader class.
First, we open the input stream to access the excel file.
InputStream is = new FileInputStream("employees.xlsx");
Then, we create the StreamingReader object through StreamingReader.Builder () method, and specify some settings, such as Rowcachesize and Buffersize.
StreamingReader reader = StreamingReader.builder()
.rowCacheSize(100)
.bufferSize(4096)
.open(is);
Next, we traversed each line of data with For cycles and created an Employee object to save employees' information.For each line, we use the getcell method to obtain the value of each cell and set it to the corresponding attributes of the Employee object.
for (Row row : reader) {
Employee employee = new Employee();
Cell cell = row.getCell(0);
employee.setId((int) cell.getNumericCellValue());
cell = row.getCell(1);
employee.setName(cell.getStringCellValue());
cell = row.getCell(2);
employee.setAge((int) cell.getNumericCellValue());
cell = row.getCell(3);
employee.setSalary(cell.getNumericCellValue());
System.out.println(employee);
}
Finally, we print out the information of each employee.
System.out.println(employee);
Through the above code example, we can use the Streaming Excel Reader framework to highly read the data of the large Excel file and perform corresponding processing and display.
Summarize:
This article introduces the application example of the Streaming Excel Reader framework, and provides the corresponding Java source analysis.This framework can easily handle large Excel files through efficient memory management and rapid data reading capabilities.
