Java實現導出Excel

      本文將介紹在Java Web中使用Apache POI實現管理系統中常見的導出Excel功能。

      首先在pom.xml中導入poi的依賴包：

<dependency>
	<groupId>org.apache.poi</groupId>
	<artifactId>poi</artifactId>
	<version>3.6</version>
</dependency>

      然後編寫工具類ExcelUtil.java，具體內容及解釋如下：

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;

public class ExcelUtil {

	public static HSSFWorkbook getHSSFWorkbook(String sheetName, String[] title, String[][] values, HSSFWorkbook wb) {

		// 第一步，創建一個HSSFWorkbook，對應一個Excel文件
		if (wb == null) {
			wb = new HSSFWorkbook();
		}

		// 第二步，在workbook中添加一個sheet,對應Excel文件中的sheet
		HSSFSheet sheet = wb.createSheet(sheetName);

		// 第三步，在sheet中添加表頭第0行,注意老版本poi對Excel的行數列數有限制
		HSSFRow row = sheet.createRow(0);

		// 第四步，創建單元格，並設置值表頭 設置表頭居中
		HSSFCellStyle style = wb.createCellStyle();
		style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 創建一個居中格式

		// 聲明列對象
		HSSFCell cell = null;

		// 創建標題
		for (int i = 0; i < title.length; i++) {
			cell = row.createCell(i);
			cell.setCellValue(title[i]);
			cell.setCellStyle(style);
		}

		// 創建內容
		for (int i = 0; i < values.length; i++) {
			row = sheet.createRow(i + 1);
			for (int j = 0; j < values[i].length; j++) {
				// 將內容按順序賦給對應的列對象
				row.createCell(j).setCellValue(values[i][j]);
			}
		}
		return wb;
	}
}

      最後直接在controller中使用即可，這裏筆者使用購房網站的信息作爲例子，在實現時需要根據業務的數據修改下面方法：

@RequestMapping(value = "/export")
@ResponseBody
public void export(HttpServletRequest request, HttpServletResponse response) throws Exception {
	//獲取數據
	Map<String, Object> data = requirementService.query(null);
	List<Requirement> list = (List<Requirement>) data.get("requirements");
	//excel標題
	String[] title = {"id","姓名","手機號","城市","縣區","房源","地鐵線","地鐵站","售價","面積","房型","用途","權屬","樓層","朝向",
			"樓齡","有無電梯","裝修","諮詢時間","備註"};
	//excel文件名
	String fileName = "購房需求信息表"+System.currentTimeMillis()+".xls";
	//sheet名
	String sheetName = "購房需求信息表";
	
	String[][] content = new String[list.size()+1][title.length];
	for (int i = 0; i < list.size(); i++) {
		Requirement r = list.get(i);
		System.out.println(r.toString());
		content[i][0] = r.getId()+"";
		content[i][1] = r.getUsername();
		content[i][2] = r.getPhone();
		content[i][3] = r.getCity();
		content[i][4] = r.getDistrict();
		content[i][5] = r.getVillage();
		content[i][6] = r.getLineNum();
		content[i][7] = r.getStationName();
		content[i][8] = r.getPrice();
		content[i][9] = r.getSquareMeter();
		content[i][10] = r.getHouseKind();
		content[i][11] = r.getUasge();
		content[i][12] = r.getOwnerShip();
		content[i][13] = r.getFloor();
		content[i][14] = r.getDirection();
		content[i][15] = r.getAge();
		content[i][16] = r.getElevator();
		content[i][17] = r.getDecoration();
		content[i][18] = sdf.format(r.getDate());
		content[i][19] = r.getRemark();
		}
	//創建HSSFWorkbook 
	HSSFWorkbook wb = ExcelUtil.getHSSFWorkbook(sheetName, title, content, null);
	//響應到客戶端
	try {
		this.setResponseHeader(response, fileName);
		OutputStream os = response.getOutputStream();
			wb.write(os);
			os.flush();
			os.close();
 	} catch (Exception e) {
 		e.printStackTrace();
 	}
}

//發送響應流方法
public void setResponseHeader(HttpServletResponse response, String fileName) {
    try {
        try {
            fileName = new String(fileName.getBytes(),"ISO8859-1");
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        response.setContentType("application/octet-stream;charset=ISO8859-1");
        response.setHeader("Content-Disposition", "attachment;filename="+ fileName);
        response.addHeader("Pargam", "no-cache");
        response.addHeader("Cache-Control", "no-cache");
    } catch (Exception ex) {
        ex.printStackTrace();
    }
}

      部署Java Web後直接訪問就可以生成並下載Excel表格了。So easy !