后端导出excel

@@ -54,6 +54,24 @@
             <version>1.18.10</version>
             <scope>compile</scope>
         </dependency>
+        <!--        excel导出-->
+        <dependency>
+            <groupId>org.apache.poi</groupId>
+            <artifactId>poi-ooxml</artifactId>
+            <version>4.1.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat.embed</groupId>
+            <artifactId>tomcat-embed-core</artifactId>
+            <version>9.0.30</version>
+            <scope>compile</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat.embed</groupId>
+            <artifactId>tomcat-embed-core</artifactId>
+            <version>9.0.30</version>
+            <scope>compile</scope>
+        </dependency>
     </dependencies>
 
     <build>

+package com.tianbo.util.POI;
+
+
+import lombok.extern.slf4j.Slf4j;
+import org.apache.poi.hssf.usermodel.HSSFWorkbook;
+import org.apache.poi.ss.usermodel.*;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+
+import javax.servlet.http.HttpServletResponse;
+import java.io.*;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * @author: lucifer
+ * @description: Excel导出工具类
+ */
+@Slf4j
+public class ExportExcelUtil<T> {
+    /**
+     * excel ./xls后缀
+     */
+    public static final String EXTENSION_XLS = ".xls";
+
+
+    /**
+     * excel ./xlsx后缀
+     */
+    public static final String EXTENSION_XLSX = ".xlsx";
+
+    /**
+     * 导出文件夹路径
+     */
+    public static final String EXCEL_PATH = "./upload/";
+
+
+
+    /**
+     * 兼容.xls和.xlsx格式
+     *
+     * @param originalFilename
+     * @return
+     */
+    private Workbook getWorkbook(String originalFilename) {
+        Workbook workbook = null;
+        if (originalFilename.endsWith(EXTENSION_XLS)) {
+            workbook = new HSSFWorkbook();
+        } else if (originalFilename.endsWith(EXTENSION_XLSX)) {
+            workbook = new XSSFWorkbook();
+        }
+        return workbook;
+    }
+
+
+    /**
+     * 导出
+     *
+     * @param originalFilename
+     * @param sheetName
+     * @param headers
+     * @param columns
+     * @param lists
+     * @throws Exception
+     */
+    public void export(String originalFilename, String sheetName, String[] headers, String[] columns, List<T> lists,HttpServletResponse response) throws Exception {
+        Workbook workbook = getWorkbook(originalFilename);
+        Sheet sheet = workbook.createSheet(sheetName);
+        sheet.setDefaultColumnWidth(15);
+        //设置表头样式
+        CellStyle style = setHeaderStyle(workbook);
+        Row row = sheet.createRow(0);
+        for (int i = 0; i < headers.length; i++) {
+            Cell headerCell = row.createCell(i);
+            headerCell.setCellValue(headers[i]);
+            headerCell.setCellStyle(style);
+        }
+        Iterator<T> it = lists.iterator();
+        int rowIndex = 0;
+        while (it.hasNext()) {
+            rowIndex++;
+            row = sheet.createRow(rowIndex);
+            T t = it.next();
+            Field[] fields = t.getClass()
+                    .getDeclaredFields();
+            for (int i = 0; i < fields.length; i++) {
+                Field field = fields[i];
+                String fieldName = field.getName();
+                for (int j = 0; j < columns.length; j++) {
+                    if (fieldName.equals(columns[j])) {
+                        String getMethodName = "get" +
+                                fieldName.substring(0, 1).
+                                        toUpperCase() + fieldName.
+                                substring(1);
+                        Class cls = t.getClass();
+                        Method getMethod = cls.getMethod(
+                                getMethodName, new Class[]{});
+                        Object val = getMethod.invoke(
+                                t, new Object[]{});
+                        String textVal;
+                        if (null != val) {
+                            textVal = val.toString();
+                        } else {
+                            textVal = "";
+                        }
+                        Cell cell = row.createCell(j);
+                        cell.setCellValue(textVal);
+//                        CellStyle cellStyle = setCellStyle(workbook, i);
+                        cell.setCellStyle(style);
+                        //单元格列宽设置
+                        sheet.autoSizeColumn(j);
+                        sheet.setColumnWidth(j, sheet.getColumnWidth(j)*17/10 > 255 * 256 ? 255 * 256 : sheet.getColumnWidth(j)*17/10);
+
+                        log.info("i:===============" + i + ",j:================" + j + ",textVal:" + textVal);
+                    }
+                }
+            }
+        }
+        String filename = sheetName + System.currentTimeMillis() + ".xls";
+        //判断是否有文件夹，没有就创建
+        File file = new File(EXCEL_PATH);
+        if (!file.exists()) {
+            file.mkdirs();
+        }
+        String filepath = EXCEL_PATH + filename;
+
+
+        System.out.println("filepath:" + filepath);
+        FileOutputStream out = new FileOutputStream(filepath);
+        workbook.write(out);
+        out.close();
+
+        downloadExcel(filepath, response);
+    }
+
+    /**
+     * 设置表头样式
+     *
+     * @param workbook
+     * @return
+     */
+    private CellStyle setHeaderStyle(Workbook workbook) {
+        CellStyle cellStyle = workbook.createCellStyle();
+        //水平居中
+        cellStyle.setAlignment(HorizontalAlignment.CENTER_SELECTION);
+        //垂直居中
+        cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
+        //设置边框
+        cellStyle.setBorderTop(BorderStyle.THIN);
+        cellStyle.setBorderRight(BorderStyle.THIN);
+        cellStyle.setBorderBottom(BorderStyle.THIN);
+        cellStyle.setBorderLeft(BorderStyle.THIN);
+        //设置字体
+        Font cellFont = workbook.createFont();
+        cellFont.setBold(true);
+        cellStyle.setFont(cellFont);
+        return cellStyle;
+    }
+
+    /**
+     * 设置单元格样式
+     */
+    private CellStyle setCellStyle(Workbook workbook, int i) {
+        CellStyle cellStyle = workbook.createCellStyle();
+        //奇数列 左对齐
+        if ((i & 1) != 1) {
+            cellStyle.setAlignment(HorizontalAlignment.LEFT);
+        } else {
+            //水平居中
+            cellStyle.setAlignment(HorizontalAlignment.CENTER_SELECTION);
+        }
+        //垂直居中
+        cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
+        //设置边框
+        cellStyle.setBorderTop(BorderStyle.THIN);
+        cellStyle.setBorderRight(BorderStyle.THIN);
+        cellStyle.setBorderBottom(BorderStyle.THIN);
+        cellStyle.setBorderLeft(BorderStyle.THIN);
+        //设置字体
+        Font cellFont = workbook.createFont();
+        cellFont.setFontName("仿宋_GB2312");
+        cellStyle.setFont(cellFont);
+        return cellStyle;
+    }
+
+
+    /**
+     * 下载
+     */
+    public static void downloadExcel(String filepath, HttpServletResponse response)
+            throws IOException {
+        File file = new File(filepath);
+        String fileName = file.getName();
+        response.setContentType("application/vnd.ms-excel;charset=utf-8");
+        response.addHeader("Content-Transfer-Encoding", "binary");
+        response.addHeader("Content-Disposition", "attachment;filename=" + new String(fileName.getBytes("UTF-8"), "ISO8859-1"));
+        response.setCharacterEncoding("utf-8");
+        InputStream fis = new BufferedInputStream(new FileInputStream(file));
+        byte[] b = new byte[fis.available()];
+        fis.read(b);
+        response.getOutputStream().write(b);
+        fis.close();
+        log.info("导出完毕");
+    }
+
+}
+
+