使用easyExcel导出数据到excel表中

0、引入包:

compile 'com.alibaba:easyexcel:2.2.6'

1、通过模板生成xlsx文件：
定义模板：

组装map的列表数据：

JSONArray arrays = new JSONArray(ret);
        for (int i = 0; i < arrays.length(); i++) {
            JSONObject json = (JSONObject) arrays.get(i);
            String id = json.getString("id");
            String name = json.getString("name");
            json = json.getJSONObject("extraData");
            long folder_used = json.getLong("folder_used");
            long folder_capacity = json.getLong("folder_capacity");
            
            Map<String,Object> map = new HashMap<String, Object>();
            
            map.put("id", id);
            map.put("name", name);
            map.put("folder_used", folder_used);
            map.put("folder_capacity", folder_capacity);
            map.put("used_prcent", decimalFormat.format(folder_used/folder_capacity));
            map.put("folder_used_G", decimalFormat.format(folder_used/1024/1024/1024));
            map.put("folder_capacity_G", decimalFormat.format(folder_capacity/1024/1024/1024));
            datas.add(map);
            datas.add(map);
        }
         String templateFileName = "template.xlsx";
         String fileName =  System.currentTimeMillis() + ".xlsx";
        EasyExcel.write(fileName).withTemplate(templateFileName).sheet().doFill(datas);

关键代码只有一行：

EasyExcel.write(fileName).withTemplate(templateFileName).sheet().doFill(datas);

2、无模板，直接写文件

定义model类：

import com.alibaba.excel.annotation.ExcelProperty;

public class ExportData {

    @ExcelProperty("ID")
    private String id;
    @ExcelProperty("名称")
    private String name;
    @ExcelProperty("类型")
    private String idType;
    @ExcelProperty("总空间")
    private float capacity;
    @ExcelProperty("已用空间")
    private float used;
    
    
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getIdType() {
        return idType;
    }
    public void setIdType(String idType) {
        this.idType = idType;
    }
    public float getCapacity() {
        return capacity;
    }
    public void setCapacity(float capacity) {
        this.capacity = capacity;
    }
    public float getUsed() {
        return used;
    }
    public void setUsed(float used) {
        this.used = used;
    }
    
}

组装list，填入

List<ExportData>  datas = getData()
String fileName = System.currentTimeMillis() + ".xlsx";
EasyExcel.write(fileName, ExportData.class).sheet("模板").doWrite(datas);

组装多个，生成多个sheet

public static void export(String fileName,List<List<ExportData>> datas,List<String> sheetNames) {
        ExcelWriter excelWriter = null;
        
        try {
            // 这里 指定文件
            excelWriter = EasyExcel.write(fileName).build();
            for (int i = 0; i < datas.size(); i++) {
                // 每次都要创建writeSheet 这里注意必须指定sheetNo 而且sheetName必须不一样。
                // 可以每次都变，我这里为了方便 所以用的同一个class 实际上可以一直变
                WriteSheet writeSheet = EasyExcel.writerSheet(i, sheetNames.get(i)).head(ExportData.class).build();
                List<ExportData> dataList = datas.get(i);
                excelWriter.write(dataList, writeSheet);
            }
        } finally {
            // 千万别忘记finish 会帮忙关闭流
            if (excelWriter != null) {
                excelWriter.finish();
            }
        }
    }