語言：java

框架：SSM

工程：maven

工具類：ExcelUtils.java

工具類下載地址：https://download.csdn.net/download/ledzcl/10234291

備註：本下載地址來源CSDN的dedzcl的部落格（連線：https://blog.csdn.net/ledzcl/article/details/79222737）

僅此備忘

1、工具類下載完成後直接放到maven工程裡，我放到了util包下

2、pom中新增jar包依賴關係

<!-- https://mvnrepository.com/artifact/org.apache.poi/poi -->
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.9</version>
</dependency>
 

jar包下載地址：https://mvnrepository.com/artifact/org.apache.poi/poi

3、controller層新增requestMapper

@ResponseBody
	@RequestMapping("/allExcel")
	public void AllExcel(HttpServletResponse res) {
		try {
			ServletOutputStream out = res.getOutputStream();
			res.setContentType("application/vnd.ms-excel");
			res.setHeader("Content-disposition", "attachment;filename=" + new SimpleDateFormat("yyyy/MM/dd HH:mm:ss").format(new Date())+URLEncoder.encode("所有", "UTF-8") + ".xls");
			Collection<Object[]> collection=new ArrayList<>();
			//
			List<Mess> allList = mService.getDownloadAll();
//			System.out.println(allList);
			for(Mess mess:allList) {
				Object[] os=new Object[20];
				os[0]=mess.getNumber();
				os[1]=mess.getSname();
				os[2]=mess.getIdcard();
				os[3]=mess.getSex();
				os[4]=mess.getBirthdate();
				os[5]=mess.getNation();
				os[6]=mess.getNativeplace();
				os[7]=mess.getHomeadress();
				os[8]=mess.getSgs();
				os[9]=mess.getSgc();
				os[10]=mess.getScadre();
				os[11]=mess.getDsfirst();
				os[12]=mess.getDssecound();
				os[13]=mess.getDsthird();
				os[14]=mess.getPname();
				os[15]=mess.getRelationship();
				os[16]=mess.getUnit();
				os[17]=mess.getDuty();
				os[18]=mess.getPhonenumber();
				os[19]=mess.getPaiwei();
				collection.add(os);
			}
			//
			String[] columnNames=new String[] {
				"編號","姓名","身份證號","性別","出身日期","民族","戶口所在地","家庭住址","畢業學校","畢業班級",
				"曾任課代表","第一心儀學校","第二心儀學校","第三心儀學校","家長姓名","與學生關係","單位","職務","聯絡方式","是否參加派位"
			};
			int[] columnIndexs=new int[] {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19};
			ExcelUtils.export(collection, "所有學生", columnNames, columnIndexs, 100, out);
			out.flush();
			out.close();
		}catch(Exception e) {
			e.printStackTrace();
		}
	}
 

解釋：

（1）呼叫工具類中的ExcelUtils.export();即可完成Excel的生成及下載

（2）HttpServletResponse需要設定content type為res.setContentType("application/vnd.ms-excel");

（3）防止中文亂碼URLEncoder.encode("所有", "UTF-8")

（4）Collection<Object[]>故需要把service層返回的list轉成object放入到Collection<Object[]>中

（5）columnNames和columnIndexs及Collection<Object[]>中的Object[]三者為一一對應關係

（6）最後別忘了out.flush();和out.close