Android 导出Excel

build.gradle

    implementation 'net.sourceforge.jexcelapi:jxl:2.6.12'

ExcelUtil

package com.example.weijian.bluetooth;

import android.content.Context;
import android.os.Environment;
import android.widget.Toast;

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

import jxl.Workbook;
import jxl.WorkbookSettings;
import jxl.format.Colour;
import jxl.write.Label;
import jxl.write.WritableCell;
import jxl.write.WritableCellFormat;
import jxl.write.WritableFont;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
import jxl.write.WriteException;

public class ExcelUtil {    public static WritableFont arial14font = null;

    public static WritableCellFormat arial14format = null;
    public static WritableFont arial10font = null;
    public static WritableCellFormat arial10format = null;
    public static WritableFont arial12font = null;
    public static WritableCellFormat arial12format = null;

    public final static String UTF8_ENCODING = "UTF-8";
    public final static String GBK_ENCODING = "GBK";


    /**
     * 单元格的格式设置 字体大小 颜色 对齐方式、背景颜色等...
     */
    public static void format() {
        try {
            arial14font = new WritableFont(WritableFont.ARIAL, 14, WritableFont.BOLD);
            arial14font.setColour(jxl.format.Colour.LIGHT_BLUE);
            arial14format = new WritableCellFormat(arial14font);
            arial14format.setAlignment(jxl.format.Alignment.CENTRE);
            arial14format.setBorder(jxl.format.Border.ALL,jxl.format.BorderLineStyle.THIN);
            arial14format.setBackground(jxl.format.Colour.VERY_LIGHT_YELLOW);

            arial10font = new WritableFont(WritableFont.ARIAL, 10, WritableFont.BOLD);
            arial10format = new WritableCellFormat(arial10font);
            arial10format.setAlignment(jxl.format.Alignment.CENTRE);
            arial10format.setBorder(jxl.format.Border.ALL,jxl.format.BorderLineStyle.THIN);
            arial10format.setBackground(Colour.GRAY_25);

            arial12font = new WritableFont(WritableFont.ARIAL, 10);
            arial12format = new WritableCellFormat(arial12font);
            arial10format.setAlignment(jxl.format.Alignment.CENTRE);//对齐格式
            arial12format.setBorder(jxl.format.Border.ALL,jxl.format.BorderLineStyle.THIN); //设置边框

        } catch (WriteException e) {
            e.printStackTrace();
        }
    }

    /**
     * 初始化Excel
     * @param fileName
     * @param colName
     */
    public static void initExcel(String fileName, String[] colName) {
        format();
        WritableWorkbook workbook = null;
        try {
            File file = new File(fileName);
            if (!file.exists()) {
                file.createNewFile();
            }
            workbook = Workbook.createWorkbook(file);
            WritableSheet sheet = workbook.createSheet("成绩表", 0);
            //创建标题栏
            sheet.addCell((WritableCell) new Label(0, 0, fileName,arial14format));
            for (int col = 0; col < colName.length; col++) {
                sheet.addCell(new Label(col, 0, colName[col], arial10format));
            }
            sheet.setRowView(0,340); //设置行高

            workbook.write();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (workbook != null) {
                try {
                    workbook.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }

    @SuppressWarnings("unchecked")
    public static  void writeObjListToExcel(List objList,String fileName, Context c) {
        if (objList != null && objList.size() > 0) {
            WritableWorkbook writebook = null;
            InputStream in = null;
            try {
                WorkbookSettings setEncode = new WorkbookSettings();
                setEncode.setEncoding(UTF8_ENCODING);
                in = new FileInputStream(new File(fileName));
                Workbook workbook = Workbook.getWorkbook(in);
                writebook = Workbook.createWorkbook(new File(fileName),workbook);
                WritableSheet sheet = writebook.getSheet(0);

                for (int j = 0; j < objList.size(); j++) {
                    ArrayList list = (ArrayList) objList.get(j);
                    for (int i = 0; i < list.size(); i++) {
                        sheet.addCell(new Label(i, j + 1, list.get(i),arial12format));
                        if (list.get(i).length() <= 5){
                            sheet.setColumnView(i,list.get(i).length()+8); //设置列宽
                        }else {
                            sheet.setColumnView(i,list.get(i).length()+5); //设置列宽
                        }
                    }
                    sheet.setRowView(j+1,350); //设置行高
                }

                writebook.write();
                Toast.makeText(c, "Success", Toast.LENGTH_SHORT).show();
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if (writebook != null) {
                    try {
                        writebook.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }

                }
                if (in != null) {
                    try {
                        in.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }

        }
    }

    public static String getSDPath() {
        File sdDir = null;
        boolean sdCardExist = Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);
        if (sdCardExist) {
            sdDir = Environment.getExternalStorageDirectory();
        }
        String dir = sdDir.toString();
        return dir;
    }

    public static void makeDir(File dir) {
        if (!dir.getParentFile().exists()) {
            makeDir(dir.getParentFile());
        }
        dir.mkdir();
    }

}

MainActivity.java

    /**
     * 导出excel
     */
    public void exportExcel() {
        String[] title = { "时间","压力"};

        File file = new File(ExcelUtil.getSDPath() + "/bluetooth");
        ExcelUtil.makeDir(file);

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String time = sdf.format(new Date());//Calendar.getInstance().toString();

        String fileName = file.toString() + "/"+testId+"-"+time+".xls";

        ExcelUtil.initExcel(fileName, title);
        ExcelUtil.writeObjListToExcel(getRecordData(), fileName, this);
    }

    /**
     * 将数据集合 转化成ArrayList>
     * @return
     */
    private  ArrayList> getRecordData() {
        ArrayList> recordList = new ArrayList<>();
        for (int i = 0; i  beanList = new ArrayList();
            beanList.add(timeTexts.get(i));
            beanList.add(values.get(i).getY()+"");
            recordList.add(beanList);
        }
        return recordList;
    }