自定義工具類?

自定義注解

自定義注解

package com.learn.domain.poi;import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target;@Retention(RetentionPolicy.RUNTIME) @Target(ElementType.FIELD) public @interface ExcelAttribute {/** 對應的列名稱 */String name() default "";/** 列序號 */int sort();/** 字段類型對應的格式 */String format() default "";}

導出工具類?

package com.learn.common.poi.utils;import com.learn.domain.poi.ExcelAttribute; import lombok.Getter; import lombok.Setter; import org.apache.poi.hssf.usermodel.*; import org.apache.poi.poifs.filesystem.POIFSFileSystem; import org.apache.poi.ss.formula.functions.T; import org.apache.poi.ss.usermodel.*; import org.apache.poi.xssf.usermodel.XSSFWorkbook;import javax.servlet.http.HttpServletResponse; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.lang.reflect.Field; import java.net.URLEncoder; import java.util.ArrayList; import java.util.LinkedList; import java.util.List; import java.util.concurrent.atomic.AtomicInteger;@Getter @Setter public class ExcelExportUtil<T> {private int rowIndex;private int styleIndex;private String templatePath;private Class clazz;private Field fields[];public ExcelExportUtil(Class clazz,int rowIndex,int styleIndex) {this.clazz = clazz;this.rowIndex = rowIndex;this.styleIndex = styleIndex;fields = clazz.getDeclaredFields();}/*** 基于注解導出*/public void export(HttpServletResponse response,InputStream is, List<T> objs,String fileName) throws Exception {XSSFWorkbook workbook = new XSSFWorkbook(is);Sheet sheet = workbook.getSheetAt(0);CellStyle[] styles = getTemplateStyles(sheet.getRow(styleIndex));AtomicInteger datasAi = new AtomicInteger(rowIndex);for (T t : objs) {Row row = sheet.createRow(datasAi.getAndIncrement());for(int i=0;i<styles.length;i++) {Cell cell = row.createCell(i);cell.setCellStyle(styles[i]);for (Field field : fields) {if(field.isAnnotationPresent(ExcelAttribute.class)){field.setAccessible(true);ExcelAttribute ea = field.getAnnotation(ExcelAttribute.class);if(i == ea.sort()) {cell.setCellValue(field.get(t).toString());}}}}}fileName = URLEncoder.encode(fileName, "UTF-8");response.setContentType("application/octet-stream");response.setHeader("content-disposition", "attachment;filename=" + new String(fileName.getBytes("ISO8859-1")));response.setHeader("filename", fileName);workbook.write(response.getOutputStream());}public CellStyle[] getTemplateStyles(Row row) {CellStyle [] styles = new CellStyle[row.getLastCellNum()];for(int i=0;i<row.getLastCellNum();i++) {styles[i] = row.getCell(i).getCellStyle();}return styles;} }

導入工具類?

package com.learn.common.poi.utils;import com.learn.domain.poi.ExcelAttribute; import org.apache.poi.hssf.usermodel.*; import org.apache.poi.poifs.filesystem.POIFSFileSystem; import org.apache.poi.ss.format.CellFormat; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.ss.usermodel.DateUtil; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.xssf.usermodel.XSSFWorkbook;import java.io.FileInputStream; import java.io.InputStream; import java.lang.reflect.Field; import java.math.BigDecimal; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.List;public class ExcelImportUtil<T> {private Class clazz;private Field fields[];public ExcelImportUtil(Class clazz) {this.clazz = clazz;fields = clazz.getDeclaredFields();}/*** 基于注解讀取excel*/public List<T> readExcel(InputStream is, int rowIndex,int cellIndex) {List<T> list = new ArrayList<T>();T entity = null;try {XSSFWorkbook workbook = new XSSFWorkbook(is);Sheet sheet = workbook.getSheetAt(0);// 不準確int rowLength = sheet.getLastRowNum();System.out.println(sheet.getLastRowNum());for (int rowNum = rowIndex; rowNum <= sheet.getLastRowNum(); rowNum++) {Row row = sheet.getRow(rowNum);entity = (T) clazz.newInstance();System.out.println(row.getLastCellNum());for (int j = cellIndex; j < row.getLastCellNum(); j++) {Cell cell = row.getCell(j);for (Field field : fields) {if(field.isAnnotationPresent(ExcelAttribute.class)){field.setAccessible(true);ExcelAttribute ea = field.getAnnotation(ExcelAttribute.class);if(j == ea.sort()) {field.set(entity, covertAttrType(field, cell));}}}}list.add(entity);}} catch (Exception e) {e.printStackTrace();}return list;}/*** 類型轉換 將cell 單元格格式轉為 字段類型*/private Object covertAttrType(Field field, Cell cell) throws Exception {String fieldType = field.getType().getSimpleName();if ("String".equals(fieldType)) {return getValue(cell);}else if ("Date".equals(fieldType)) {return new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").parse(getValue(cell)) ;}else if ("int".equals(fieldType) || "Integer".equals(fieldType)) {return Integer.parseInt(getValue(cell));}else if ("double".equals(fieldType) || "Double".equals(fieldType)) {return Double.parseDouble(getValue(cell));}else {return null;}}/*** 格式轉為String* @param cell* @return*/public String getValue(Cell cell) {if (cell == null) {return "";}switch (cell.getCellType()) {case STRING:return cell.getRichStringCellValue().getString().trim();case NUMERIC:if (DateUtil.isCellDateFormatted(cell)) {Date dt = DateUtil.getJavaDate(cell.getNumericCellValue());return new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(dt);} else {// 防止數值變成科學計數法String strCell = "";Double num = cell.getNumericCellValue();BigDecimal bd = new BigDecimal(num.toString());if (bd != null) {strCell = bd.toPlainString();}// 去除 浮點型 自動加的 .0if (strCell.endsWith(".0")) {strCell = strCell.substring(0, strCell.indexOf("."));}return strCell;}case BOOLEAN:return String.valueOf(cell.getBooleanCellValue());default:return "";}} }

?

總結

以上是生活随笔為你收集整理的自定义工具类：工具类介绍的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。