Java implements import and export of Excel tables

Note that this approach requires the introduction of the POI jar package

Build a Student class first
public class Student {

private String name;
private int age;
private int grade;

}

Add get set and its parameter and parameterless construction method;

Prepare the test data set to create an Excel table

public class Exceloperate {

public static void Main (string[] args) {
Create an Excel table
Createexcel (Getstudent ());

       //Read Excel form
        list< student> list = Readexcel ();
        System.out.println (list.tostring ());
   }

/**
* Initialize Data
*
* @return Data
*/
private static list<student> getstudent () {
list<student> list = new arraylist<student> ();
Student student1 = new Student ("Xiaoming", 8, "second Grade");
Student Student2 = new Student ("Small aperture", 9, "third grade");
Student Student3 = new Student ("Floret", 10, "grade Four");
List.add (STUDENT1);
List.add (Student2);
List.add (STUDENT3);
return list;
}

/**
* Create Excel
*
* @param list
* Data
*/
private static void Createexcel (List<student> List) {
Create an Excel file
Hssfworkbook workbook = new Hssfworkbook ();
Create a worksheet
Hssfsheet sheet = workbook.createsheet ("Student form One");
Add header row
Hssfrow hssfrow = sheet.createrow (0);
Set cell formatting to center
Hssfcellstyle CellStyle = Workbook.createcellstyle ();
Cellstyle.setalignment (Hssfcellstyle.align_center);

Add header Content
Hssfcell Headcell = Hssfrow.createcell (0);
Headcell.setcellvalue ("name");
Headcell.setcellstyle (CellStyle);

Headcell = Hssfrow.createcell (1);
Headcell.setcellvalue ("Age");
Headcell.setcellstyle (CellStyle);

Headcell = Hssfrow.createcell (2);
Headcell.setcellvalue ("grade");
Headcell.setcellstyle (CellStyle);

Add Data content
for (int i = 0; i < list.size (); i++) {
Hssfrow = Sheet.createrow ((int) i + 1);
Student Student = List.get (i);

Create a cell and set a value
Hssfcell cell = Hssfrow.createcell (0);
Cell.setcellvalue (Student.getname ());
Cell.setcellstyle (CellStyle);

Cell = Hssfrow.createcell (1);
Cell.setcellvalue (Student.getage ());
Cell.setcellstyle (CellStyle);

            cell = Hssfrow.createcell (2);
            Cell.setcellvalue (Student.getgrade ());
            Cell.setcellstyle (CellStyle);
       }

       //Save Excel File
        try {
            OutputStream outputstream = new FileOutputStream ("D:/students.xls");
            Workbook.write (outputstream);
            outputstream.close ();
       } catch (Exception e) {
             E.printstacktrace ();
       }
   }

   /**
     * Read Excel
     *
      * @return Data collection
     */
    private static list<student> Readexcel () {
        list<student> List = new Arraylist<student> ( );
        Hssfworkbook workbook = null;

try {
Reading Excel files
InputStream InputStream = new FileInputStream ("D:/students.xls");
workbook = new Hssfworkbook (InputStream);
Inputstream.close ();
} catch (Exception e) {
E.printstacktrace ();
}

Looping worksheets
for (int numsheet = 0; Numsheet < workbook.getnumberofsheets (); numsheet++) {
Hssfsheet Hssfsheet = Workbook.getsheetat (Numsheet);
if (Hssfsheet = = null) {
Continue
}
Loop Line
for (int rowNum = 1; rowNum <= hssfsheet.getlastrownum (); rownum++) {
Hssfrow Hssfrow = Hssfsheet.getrow (RowNum);
if (Hssfrow = = null) {
Continue
}

Save the contents of a cell in a collection
Student Student = new Student ();

                Hssfcell cell = Hssfrow.getcell (0);
                if (cell = = null) {
                     continue;
               }
                Student.setname ( Cell.getstringcellvalue ());

                cell = Hssfrow.getcell (1);
                if (cell = = null) {
                     continue;
               }
                Student.setage (( int) cell.getnumericcellvalue ());

Cell = Hssfrow.getcell (2);
if (cell = = null) {
Continue
}
Student.setgrade (Cell.getstringcellvalue ());

List.add (student);
}
}
return list;
}

}

Java implements import and export of Excel tables