1,需要依赖的jar包,
<!-- POI(operate excel) start --> <!-- the version of the following POI packages must be consistent --> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi</artifactId> <version>3.17</version> </dependency> <!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml --> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-ooxml</artifactId> <version>3.17</version> </dependency> <!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml-schemas --> <!-- the dependent jar package to create .xlsx file --> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-ooxml-schemas</artifactId> <version>3.17</version> </dependency> <!-- https://mvnrepository.com/artifact/org.apache.xmlbeans/xmlbeans --> <dependency> <groupId>org.apache.xmlbeans</groupId> <artifactId>xmlbeans</artifactId> <version>2.6.0</version> </dependency> <!-- https://mvnrepository.com/artifact/commons-collections/commons-collections --> <dependency> <groupId>commons-collections</groupId> <artifactId>commons-collections</artifactId> <version>3.2.2</version> </dependency> <!-- https://mvnrepository.com/artifact/dom4j/dom4j --> <dependency> <groupId>dom4j</groupId> <artifactId>dom4j</artifactId> <version>1.6.1</version> </dependency> <!-- POI end -->
2,创建Excel(.xls 和 .xlsx的方法)我详细地写了如何创建.xls 文件,创建.xlsx文件就是引用的类不一样,步骤基本上是一样的。
/** * */ package com.nokia.jira.utils; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import org.apache.poi.hssf.usermodel.HSSFCell; import org.apache.poi.hssf.usermodel.HSSFCellStyle; import org.apache.poi.hssf.usermodel.HSSFRow; import org.apache.poi.hssf.usermodel.HSSFSheet; import org.apache.poi.hssf.usermodel.HSSFWorkbook; import org.apache.poi.hssf.util.HSSFColor; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.ss.usermodel.CellStyle; import org.apache.poi.ss.usermodel.CellType; import org.apache.poi.ss.usermodel.Color; import org.apache.poi.ss.usermodel.HorizontalAlignment; import org.apache.poi.ss.usermodel.VerticalAlignment; import org.apache.poi.xssf.usermodel.XSSFWorkbook; /** * @author bpan * * created 2018年2月27日 */ public class CreateExcelFile { private static HSSFWorkbook hWorkbook = null; private static XSSFWorkbook xWorkbook = null; /** * 判断文件是否存在. * @param fileDir 文件路径 * @return */ public static boolean fileExist(String fileDir){ boolean flag = false; File file = new File(fileDir); flag = file.exists(); return flag; } /** * 判断文件的sheet是否存在. * @param fileDir 文件路径 * @param sheetName 表格索引名 * @return boolean */ public static boolean XlsSheetExist(String fileDir, String sheetName){ boolean flag = false; File file = new File(fileDir); if (file.exists()) { //文件存在,创建workbook try { hWorkbook = new HSSFWorkbook(new FileInputStream(file)); HSSFSheet sheet = hWorkbook.getSheet(sheetName); if (sheet!=null) { //文件存在,sheet存在 flag = true; } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } }else { //文件不存在 flag = false; } return flag; } /** * 创建新excel(xls). * @param fileDir excel的路径 * @param sheetNames 要创建的表格索引列表 * @param titleRow excel的第一行即表格头 */ public static void createExcelXls(String fileDir, List<String> sheetNames, String titleRow[]){ //创建workbook hWorkbook = new HSSFWorkbook(); //新建文件 FileOutputStream fileOutputStream = null; HSSFRow row = null; try { CellStyle cellStyle = hWorkbook.createCellStyle(); cellStyle.setAlignment(HorizontalAlignment.LEFT); cellStyle.setVerticalAlignment(VerticalAlignment.BOTTOM); //添加Worksheet(不添加sheet时生成的xls文件打开时会报错) for(int i = 0; i<sheetNames.size(); i++){ hWorkbook.createSheet(sheetNames.get(i)); hWorkbook.getSheet(sheetNames.get(i)).createRow(0); //添加表头, 创建第一行 row = hWorkbook.getSheet(sheetNames.get(i)).createRow(0); row.setHeight((short)(20*20)); for (short j = 0; j < titleRow.length; j++) { HSSFCell cell = row.createCell(j, CellType.BLANK); cell.setCellValue(titleRow[j]); cell.setCellStyle(cellStyle); } fileOutputStream = new FileOutputStream(fileDir); hWorkbook.write(fileOutputStream); } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { if (fileOutputStream != null) { try { fileOutputStream.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } /** * 删除文件. * @param fileDir 文件路径 * @return 如果文件不存在返回false, 如果文件存在删除成功之后返回true */ public static boolean deleteExcel(String fileDir) { boolean flag = false; File file = new File(fileDir); // 判断目录或文件是否存在 if (!file.exists()) { // 不存在返回 false return flag; } else { // 判断是否为文件 if (file.isFile()) { // 为文件时调用删除文件方法 file.delete(); flag = true; } } return flag; } /** * 往excel(xls)中写入(已存在的数据无法写入). * @param fileDir 文件路径 * @param sheetName 表格索引 * @param object * @throws Exception */ public static void writeToExcelXls(String fileDir, String sheetName, List<Map<String,String>> mapList) throws Exception{ //创建workbook File file = new File(fileDir); try { hWorkbook = new HSSFWorkbook(new FileInputStream(file)); }catch(FileNotFoundException e){ e.printStackTrace(); }catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } //文件流 FileOutputStream fileOutputStream = null; HSSFSheet sheet = hWorkbook.getSheet(sheetName); // 获取表格的总行数 // int rowCount = sheet.getLastRowNum() + 1; // 需要加一 //获取表头的列数 int columnCount = sheet.getRow(0).getLastCellNum(); try { // 获得表头行对象 HSSFRow titleRow = sheet.getRow(0); //创建单元格显示样式 CellStyle cellStyle = hWorkbook.createCellStyle(); cellStyle.setAlignment(HorizontalAlignment.LEFT); cellStyle.setVerticalAlignment(VerticalAlignment.BOTTOM); if(titleRow!=null){ for(int rowId = 0; rowId < mapList.size(); rowId++){ Map<String,String> map = mapList.get(rowId); HSSFRow newRow=sheet.createRow(rowId+1); newRow.setHeight((short)(20*20));//设置行高 基数为20 for (short columnIndex = 0; columnIndex < columnCount; columnIndex++) { //遍历表头 //trim()的方法是删除字符串中首尾的空格 String mapKey = titleRow.getCell(columnIndex).toString().trim(); HSSFCell cell = newRow.createCell(columnIndex); cell.setCellStyle(cellStyle); cell.setCellValue(map.get(mapKey)==null ? null : map.get(mapKey).toString()); } } } fileOutputStream = new FileOutputStream(fileDir); hWorkbook.write(fileOutputStream); } catch (Exception e) { throw e; } finally { try { if (fileOutputStream != null) { fileOutputStream.close(); } } catch (IOException e) { e.printStackTrace(); } } } /** * 创建Excel(xlsx) * @param fileDir 文件名称及地址 * @param sheetName sheet的名称 * @param titleRow 表头 */ public static void createExcelXlsx(String fileDir, String sheetName, String titleRow[]){ } public static void main(String[] args) { String fileDir = "d:\\workbook.xls"; List<String> sheetName = new ArrayList<>(); sheetName.add("A"); sheetName.add("B"); sheetName.add("C"); System.out.println(sheetName); String[] title = {"id","name","password"}; CreateExcelFile.createExcelXls(fileDir, sheetName, title); List<Map<String,String>> userList1 = new ArrayList<Map<String,String>>(); Map<String,String> map=new HashMap<String,String>(); map.put("id", "111"); map.put("name", "张三"); map.put("password", "111!@#"); Map<String,String> map2=new HashMap<String,String>(); map2.put("id", "222"); map2.put("name", "李四"); map2.put("password", "222!@#"); Map<String,String> map3=new HashMap<String,String>(); map3.put("id", "33"); map3.put("name", "王五"); map3.put("password", "333!@#"); userList1.add(map); userList1.add(map2); userList1.add(map3); Map<String, List<Map<String, String>>> users = new HashMap<>(); users.put("A", userList1); List<Map<String,String>> userList2 = new ArrayList<Map<String,String>>(); Map<String,String> map4=new HashMap<String,String>(); map4.put("id", "111"); map4.put("name", "张三"); map4.put("password", "111!@#"); Map<String,String> map5=new HashMap<String,String>(); map5.put("id", "222"); map5.put("name", "李四"); map5.put("password", "222!@#"); Map<String,String> map6=new HashMap<String,String>(); map6.put("id", "33"); map6.put("name", "王五"); map6.put("password", "333!@#"); userList2.add(map4); userList2.add(map5); userList2.add(map6); users.put("B", userList2); List<Map<String,String>> userList3 = new ArrayList<Map<String,String>>(); users.put("C", userList3); System.out.println(sheetName.size()); //删除List 集合中特定的元素 for(Iterator<String> sheeNameIterator = sheetName.iterator();sheeNameIterator.hasNext();){ String sheet = sheeNameIterator.next(); if ( users.get(sheet).size() == 0) { sheeNameIterator.remove(); } } System.out.println(sheetName.size()); createExcelXls(fileDir, sheetName, title); for (int j = 0; j < sheetName.size(); j++) { try { writeToExcelXls(fileDir, sheetName.get(j), users.get(sheetName.get(j))); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }
3,至于如何设置单元格的样式,大家可以根据自己的兴趣去研究一下。