SpringBoot整合EasyExcel进行大数据处理的方法详解

    <dependencies>
        <!--        开发web 项目和启动Springboot必须添加的-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.4.1</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>3.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>2.0.3.graal</version>
            <scope>compile</scope>
        </dependency>

    </dependencies>

@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class EmployeesEntity {
    @ExcelProperty(index = 0)
    private Integer no;  //工号
    @ExcelProperty(index = 1)
    private String name;
    @ExcelProperty(index = 2)
    private Double fund;
    @ExcelProperty(index = 3)
    private Double postSalary;
    @ExcelProperty(index = 4)
    private Double performanceOf;
    @ExcelProperty(index = 5)
    private Double allWork;
    @ExcelProperty(index = 6)
    private Double violations;
    @ExcelProperty(index = 7)
    private Double traffic;
    @ExcelProperty(index = 8)
    private Double communication;
}

public class EmployeesListener extends AnalysisEventListener<EmployeesEntity> {


    /**
     * 这个每一条数据解析都会来调用
     *
     * @param data
     *            one row value. Is is same as {@link AnalysisContext#readRowHolder()}
     * @param context
     */
    @Override
    public void invoke(EmployeesEntity data, AnalysisContext context) {
        System.out.println("解析到一条数据:"+JSON.toJSONString(data));
    }

    /**
     * 所有数据解析完成了 都会来调用
     *
     * @param context
     */
    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {

    }


}

    @Test
    public void get(){
        File file = new File("./src/main/resources/大客户部-薪酬表.xlsx");
        String absolutePath = file.getAbsolutePath();
//        // 这里 需要指定读用哪个class去读，然后读取第一个sheet 文件流会自动关闭
        EasyExcel.read(absolutePath, EmployeesEntity.class, new EmployeesListener()).sheet().doRead();

    }

@Data
public class DemoData {
    @ExcelProperty("字符串标题")
    private String string;
    @ExcelProperty("日期标题")
    private Date date;
    @ExcelProperty("数字标题")
    private Double doubleData;
    /**
     * 忽略这个字段
     */
    @ExcelIgnore
    private String ignore;
}

//生成模拟数据
    private List<DemoData> data() {
        List<DemoData> list = new ArrayList<DemoData>();
        for (int i = 0; i < 10; i++) {
            DemoData data = new DemoData();
            data.setString("字符串" + i);
            data.setDate(new Date());
            data.setDoubleData(0.56);
            list.add(data);
        }
        return list;
    }

    /**
     * 最简单的写
     * <p>1. 创建excel对应的实体对象 参照{@link DemoData}
     * <p>2. 直接写即可
     */
    @Test
    public void simpleWrite() {
        // 写
        File file = new File("./src/main/resources/DemoData.xlsx");
        // 这里 需要指定写用哪个class去写，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
        // 如果这里想使用03 则 传入excelType参数即可
        EasyExcel.write(file.getAbsolutePath(), DemoData.class).sheet("DemoData").doWrite(data());

    }

@Data
public class FillData {
    private String name;
    private double number;
}

    @Test
    public void simpleFill() {
        // 模板注意 用{} 来表示你要用的变量 如果本来就有"{","}" 特殊字符 用"\{","\}"代替
        File templateFileName  = new File("./src/main/resources/模板.xlsx");

        File fill  = new File("./src/main/resources/fillData.xlsx");
        // 这里 会填充到第一个sheet， 然后文件流会自动关闭
        FillData fillData = new FillData();
        fillData.setName("张三");
        fillData.setNumber(5.2);
        EasyExcel.write(fill.getAbsolutePath()).withTemplate(templateFileName.getAbsolutePath()).sheet().doFill(fillData);

    }