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Java自定義注解導出Excel基于自定義實作導出Excel

基于自定義實作導出Excel

一般導入(解析Excel)導出不用Java做,這門語言不太适合做檔案處理可以使用前端的node.js或goland做檔案處理,小編寫了一套基于自定義注解的導入和導出友善大家使用。

網上找的導入導出代碼很多代碼都是基本生成Excel文檔,表頭、文檔名稱都得手動傳入參數實際實用性不強,小編基于自定義注解動态擷取這些名稱可用性非常高。

引用POM檔案

<!--    自定義注解    -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
        </dependency>

		<!--    Excle導出    -->
        <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>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml-schemas</artifactId>
            <version>3.17</version>
        </dependency>
           

建立自定義注解

  • 模型上使用該注解可以動态獲得Excel名稱
package com.monkey.excel;

import java.lang.annotation.*;

/**
 * @Author: LailaiMonkey
 * @Description:描述表格名
 * @Date:Created in 2020-08-29 16:48
 * @Modified By:
 */
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface MonkeyExcelName {
    String value();
}

           
  • 模型字段上使用該注解可以動态獲得列名
package com.monkey.excel;

import java.lang.annotation.*;

/**
 * @Author: LailaiMonkey
 * @Description:描述列名
 * @Date:Created in 2020-08-29 16:48
 * @Modified By:
 */
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface MonkeyExcelColumnName {
    String value();

    int sort() default Integer.MAX_VALUE;
}

           

建立兩個描述表格元素類

這兩類主要作用是獲得Excel和列的名稱,建立Excel時候直接使用不需要再次擷取。

  • 描述表格名稱及所有列資訊
package com.monkey.excel;

import org.apache.commons.lang3.reflect.FieldUtils;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;

/**
 * @Author: LailaiMonkey
 * @Description:描述表格名稱及所有列資訊
 * @Date:Created in 2020-08-29 16:03
 * @Modified By:
 */
public class MonkeyExcel {
    private List<MonkeyExcelColumn> columns;
    private String name;

    MonkeyExcel(Class<?> clazz) {
        this.columns = getCellName(clazz);
        this.name = getExcelName(clazz);
    }

    private List<MonkeyExcelColumn> getCellName(Class<?> clazz) {
        List<MonkeyExcelColumn> cellNames = new ArrayList<>();
        Field[] fields = FieldUtils.getAllFields(clazz);
        for (Field field : fields) {
            MonkeyExcelColumnName annotation = field.getAnnotation(MonkeyExcelColumnName.class);
            if (annotation != null) {
                cellNames.add(new MonkeyExcelColumn(annotation.value(), field.getName(), annotation.sort()));
            } else {
                cellNames.add(new MonkeyExcelColumn(field.getName(), field.getName(), Integer.MAX_VALUE));
            }
        }
        cellNames.sort(Comparator.comparingInt(MonkeyExcelColumn::getSort));
        return cellNames;
    }

    private String getExcelName(Class clazz) {
        MonkeyExcelName annotation = (MonkeyExcelName) clazz.getAnnotation(MonkeyExcelName.class);
        if (annotation != null) {
            return annotation.value();
        }
        return clazz.getSimpleName();
    }

    public List<MonkeyExcelColumn> getColumns() {
        return columns;
    }

    public String getName() {
        return name;
    }
}

           
  • 描述所有列資訊
package com.monkey.excel;

/**
 * @Author: LailaiMonkey
 * @Description:描述所有列資訊
 * @Date:Created in 2020-08-29 18:39
 * @Modified By:
 */
public class MonkeyExcelColumn {
    private String name;
    private String fieldName;
    private Integer sort;

    MonkeyExcelColumn(String name, String fieldName, Integer sort) {
        this.name = name;
        this.fieldName = fieldName;
        this.sort = sort;
    }

    public String getName() {
        return name;
    }

    public String getFieldName() {
        return fieldName;
    }

    public Integer getSort() {
        return sort;
    }
}

           

生成Excel工具類

package com.monkey.excel;

import org.apache.commons.lang3.reflect.FieldUtils;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.streaming.SXSSFSheet;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.springframework.util.CollectionUtils;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Field;
import java.net.URLEncoder;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

/**
 * @Author: LailaiMonkey
 * @Description:導出工具類
 * @Date:Created in 2020-08-29 16:02
 * @Modified By:
 */
public class MonkeyExcelExportUtils {
    public static void export(HttpServletResponse response, List<?> list) {
        if (CollectionUtils.isEmpty(list)) {
            return;
        }

        //聲明一個工作薄
        SXSSFWorkbook workbook = new SXSSFWorkbook();
        //生成一個表格
        SXSSFSheet sheet = workbook.createSheet();
        //擷取要生成表格資訊
        MonkeyExcel excelModel = new MonkeyExcel(list.get(0).getClass());
        //擷取所有列名
        List<MonkeyExcelColumn> models = excelModel.getColumns();

        //循環字段名數組,建立标題行
        Row row = sheet.createRow(0);
        for (int i = 0; i < models.size(); i++) {
            //建立列
            Cell cell = row.createCell(i);
            //設定單元類型為String
            cell.setCellType(CellType.STRING);
            cell.setCellValue(models.get(i).getName());
        }

        //建立普通行
        for (int i = 0; i < list.size(); i++) {
            //因為第一行已經用于建立标題行,故從第二行開始建立
            row = sheet.createRow(i + 1);
            for (int j = 0; j < models.size(); j++) {
                //建立列
                Cell cell = row.createCell(j);
                //集合中某行為空
                Object value = null;
                if (list.get(i) != null) {
                    value = getFieldValue(list.get(i), models.get(j).getFieldName());
                }
                cell.setCellValue(transCellType(value));
            }
        }
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        try {
            response.setHeader("Content-Disposition", "attachment;fileName=" +
                    URLEncoder.encode(excelModel.getName(), "utf-8") +
                    ".xlsx");
            response.flushBuffer();
            workbook.write(response.getOutputStream());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static Object getFieldValue(Object object, String fieldName) {
        Class<?> clazz = object.getClass();
        try {
            Field name = FieldUtils.getField(clazz, fieldName, true);
            return FieldUtils.readField(name, object, true);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
        return null;
    }

    private static String transCellType(Object value) {
        if (value instanceof Date) {
            Date date = (Date) value;
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            return sdf.format(date);
        }
        return "null".equals(String.valueOf(value)) ? "" : String.valueOf(value);
    }

}

           

使用方法

controller調用

MonkeyExcelExportUtils.export(response, 需要生成資料集合);

傳入HttpServletResponse請求和資料集合。

模型定義:

Java自定義注解導出Excel基于自定義實作導出Excel