Analysis and practice of "JXL" framework technical principles in the Java class library
Analysis and practice of "JXL" framework technical principles in the Java class library
JXL is a Java class library for reading and writing Excel files.It provides the function of creation, modification and reading of Excel files, and is very suitable for performing Excel file operations in Java applications.
1. Analysis of the principle of JXL framework
1. The structure of the JXL library
The JXL library consists of a set of Java classes and interfaces. These classes and interfaces include most of the functions required to operate the excel file.The core categories are Workbook and Sheet classes, which correspond to Excel files and worksheets, respectively.
2. The characteristics of the JXL library
The JXL library has the following characteristics:
-It is easy to use: JXL provides a simple API, enabling developers to easily create, modify and read Excel files.
-The platform: JXL can run on various Java -supported operating systems, such as Windows, Linux, and Mac.
-Card various data types: JXL can process various data types in Excel files, including text, numbers, dates, formulas, etc.
-The old version: JXL can read and modify files (.xls) in Excel 97-2003 format, but does not support files (.xlsx) in Excel 2007 format and above.
3. The working principle of the JXL library
The JXL library can realize the reading and writing operation of the excel file by using the COM interface or POI (another popular Java operation Excel library) provided by Excel.It translates the operation of the Java program into the COM interface of Excel or the API of the POI, and then the operation of the Excel file.
Second, the practice of the JXL framework
Below we will introduce some common application scenarios of the JXL library and the corresponding Java code example.
1. Create an excel file
It is very simple to use JXL to create an excel file. The following code demonstrates how to create an Excel file containing a single worksheet:
import jxl.Workbook;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
public class CreateExcel {
public static void main(String[] args) {
try {
// Create a workbook
WritableWorkbook workbook = Workbook.createWorkbook(new File("example.xls"));
// Create a worksheet
WritableSheet sheet = workbook.createSheet("Sheet1", 1);
// adding data
Label label = new Label(0, 0, "Hello World");
sheet.addCell(label);
// Save and close the workbook
workbook.write();
workbook.close();
System.out.println ("EXCEL file creation successfully!"););
} catch (Exception e) {
e.printStackTrace();
}
}
}
2. Read the excel file
It is also very simple to read the excel file with JXL. The following code demonstrates how to read the content in the Excel file:
import jxl.Workbook;
import jxl.Sheet;
import jxl.Cell;
public class ReadExcel {
public static void main(String[] args) {
try {
// Open the excel file
Workbook workbook = Workbook.getWorkbook(new File("example.xls"));
// Get the first worksheet
Sheet sheet = workbook.getSheet(0);
// retrieve data
Cell cell = sheet.getCell(0, 0);
String content = cell.getContents();
System.out.println ("Cell Content:" + Content);
// Close the workbook
workbook.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
3. Modify the excel file
It is also very simple to modify the Excel file with JXL. The following code demonstrates how to modify the content in the Excel file:
import jxl.Workbook;
import jxl.write.WritableWorkbook;
import jxl.write.WritableSheet;
import jxl.write.Label;
public class ModifyExcel {
public static void main(String[] args) {
try {
// Open the excel file
Workbook workbook = Workbook.getWorkbook(new File("example.xls"));
// Create a writeable workbook
WritableWorkbook writableWorkbook = Workbook.createWorkbook(new File("example_modified.xls"), workbook);
// Get the first worksheet
WritableSheet sheet = writableWorkbook.getSheet(0);
// change the data
Label label = new Label(0, 0, "Modified Content");
sheet.addCell(label);
// Save and close the workbook
writableWorkbook.write();
writableWorkbook.close();
workbook.close();
System.out.println ("EXCEL files are modified successfully!"););
} catch (Exception e) {
e.printStackTrace();
}
}
}
The above examples demonstrate the basic operations of the JXL library in creating, reading and modifying the Excel file. Through these examples, the simple and powerful functions of the JXL library can be experienced.
In summary, the JXL library is a developer friendly and powerful Java class library for the reading and writing operation of the Excel file.By in -depth understanding of the principles and practice of the JXL library, we can easily implement the operation of the excel file in the Java application.
