用POI 3.17读取EXCEL数据

Posted 2021-03-23 wf-zhang

导入jar 包

<dependency>
　　<groupId>org.apache.poi</groupId>
　　<artifactId>poi</artifactId>
<version>3.17</version>
</dependency>
<dependency>
　　<groupId>org.apache.poi</groupId>
　　<artifactId>poi-ooxml</artifactId>
　　<version>3.17</version>
</dependency>

 

//准备数据类

package com.wf.zhang.test;

public class Person {

    private String name;

    private Integer age;

    private String Adress;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getAdress() {
        return Adress;
    }

    public void setAdress(String adress) {
        Adress = adress;
    }

    public Person() {
    }

    public Person(String name, Integer age, String adress) {
        super();
        this.name = name;
        this.age = age;
        Adress = adress;
    }

    @Override
    public String toString() {
        return String.format("Person [name=%s, age=%s, Adress=%s]", name, age, Adress);
    }

}

Person

 

方式一    方法好多过时的

效果

 

 

package com.wf.zhang.test;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.DateUtil;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class POIUtil {

    //按照路径  列名读取文件
    public static List<Map<String, String>> readExcel(String filePath, String columns[]) {
        Sheet sheet = null;
        Row row = null;
        Row rowHeader = null;
        List<Map<String, String>> list = null;
        String cellData = null;
        Workbook wb = null;
        if (filePath == null) {
            return null;
        }
        String extString = filePath.substring(filePath.lastIndexOf("."));
        InputStream is = null;
        try {
            is = new FileInputStream(filePath);
            if (".xls".equals(extString)) {
                wb = new HSSFWorkbook(is);
            } else if (".xlsx".equals(extString)) {
                wb = new XSSFWorkbook(is);
            } else {
                wb = null;
            }
            if (wb != null) {
                // 用来存放表中数据
                list = new ArrayList<Map<String, String>>();
                // 获取第一个sheet
                sheet = wb.getSheetAt(0);
                // 获取最大行数
                int rownum = sheet.getPhysicalNumberOfRows();
                // 获取第一行
                rowHeader = sheet.getRow(0);
                row = sheet.getRow(0);
                // 获取最大列数
                int colnum = row.getPhysicalNumberOfCells();
                for (int i = 1; i < rownum; i++) {
                    Map<String, String> map = new LinkedHashMap<String, String>();
                    row = sheet.getRow(i);
                    if (row != null) {
                        for (int j = 0; j < colnum; j++) {
                            if (columns[j].equals(getCellFormatValue(rowHeader.getCell(j)))) {
                                cellData = (String) getCellFormatValue(row.getCell(j));
                                map.put(columns[j], cellData);
                            }
                        }
                    } else {
                        break;
                    }
                    list.add(map);
                }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return list;
    }

    /**
     * 获取单个单元格数据
     * @param cell
     * @return
     */
    public static Object getCellFormatValue(Cell cell) {
        Object cellValue = null;
        if (cell != null) {
            // 判断cell类型
            switch (cell.getCellType()) {
            case Cell.CELL_TYPE_NUMERIC: {
                cellValue = String.valueOf(cell.getNumericCellValue());
                break;
            }
            case Cell.CELL_TYPE_FORMULA: {
                // 判断cell是否为日期格式
                if (DateUtil.isCellDateFormatted(cell)) {
                    // 转换为日期格式YYYY-mm-dd
                    cellValue = cell.getDateCellValue();
                } else {
                    // 数字
                    cellValue = String.valueOf(cell.getNumericCellValue());
                }
                break;
            }
            case Cell.CELL_TYPE_STRING: {
                cellValue = cell.getRichStringCellValue().getString();
                break;
            }
            default:
                cellValue = "";
            }
        } else {
            cellValue = "";
        }
        return cellValue;
    }

    //测试类
    public static void main(String[] args) {
        String filePath = "C:/Users/admin/Desktop/students.xls";
        String columns[] = { "学号", "姓名", "年龄", "生日" };
        List<Map<String, String>> list = POIUtil.readExcel(filePath, columns);
        // 遍历解析出来的list
        for (Map<String, String> map : list) {
            for (Entry<String, String> entry : map.entrySet()) {
                System.out.print(entry.getKey() + ":" + entry.getValue() + ",");
            }
            System.out.println();
        }
    }

}

View Code

 

 

方式二    推荐使用

效果

 

package com.wf.zhang.test;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.DateUtil;
import org.apache.poi.ss.usermodel.Row;

public class ReadExcel {

    //调用方法
    public static void main(String[] args) {
        importXLS();
    }
    
    //读取的方法
    public static List<Student> importXLS(){
    
        ArrayList<Student> list = new ArrayList<Student>();
        
        try {
            //1、获取文件输入流
            InputStream inputStream = new FileInputStream("C:/Users/admin/Desktop/students.xls");
            //2、获取Excel工作簿对象
            HSSFWorkbook workbook = new HSSFWorkbook(inputStream);
            //3、得到Excel工作表对象
            HSSFSheet sheetAt = workbook.getSheetAt(0);
            //4、循环读取表格数据
            for (Row row : sheetAt) {
                //首行（即表头）不读取
                if (row.getRowNum() == 0) {
                    continue;
                }
                
                //读取当前行中单元格数据，索引从0开始
                int id = (int) (row.getCell(0).getNumericCellValue());
                String name = row.getCell(1).getStringCellValue();
                int age = (int) row.getCell(2).getNumericCellValue();
                String birth = row.getCell(3).getStringCellValue();
    
                Date date = DateUtil.parseYYYYMMDDDate(birth);
                
                Student st = new Student();
                st.setId(id);
                st.setName(name);
                st.setAge(age);
                st.setBirth(date);
    
                list.add(st);
            }
            //打印
            System.out.println(list.toString());
            //5、关闭流
            workbook.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
       return list;
    }
    
    
}