發布時間：2018-11-15
技術：springboot1.5.6 + maven3.0.5 + jdk1.8
概述
Springboot最便捷的Excel導出,只需要一個配置文件即可搞定
詳細
一、准備工作
先在pom文件添加依賴如下圖所示：
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- 使用Jasper引擎解析JSP -->
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<scope>provided</scope>
</dependency>
<!-- jstl標簽 -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.8.1</version>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>27.0-jre</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.17</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.17</version>
</dependency>
</dependencies>
二、程序實現
1、添加excel導出的person-export-config文件
<?xml version="1.0" encoding="UTF-8"?> <exportFile> <fileName>exportConfig</fileName> <exportType>0</exportType> <cell> <title>序號</title> <alias>index</alias> </cell> <cell> <title>姓名</title> <alias>name</alias> </cell> <cell> <title>年齡</title> <alias>age</alias> </cell> <cell> <title>性別</title> <alias>sex</alias> </cell> <cell> <title>日期</title> <alias>date</alias> </cell> </exportFile>
其中exportType:0表示導出EXCEL2007，exportType:1表示導出csv文件
title導出展示列的title名，alias表示映射的字段名
2、從classpath獲取person-export-config.xml文件
從classpath獲取person-export-coing.xml文件並轉為inputStresm
ClassPathResource classPathResource = new ClassPathResource("export/person-export-config.xml");
InputStream inputStream = classPathResource.getInputStream();
ExportConfig exportConfig = ExportConfigFactory.getExportConfig(inputStream);
3、解析person-export-config.xml文件
主要代碼如下：
private static ExportConfig getExportCells(InputStream inputStream) throws FileExportException {
ExportConfig exportConfig = new ExportConfig();
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = null;
Document document = null;
try {
dBuilder = dbFactory.newDocumentBuilder();
document = dBuilder.parse(inputStream);
} catch (ParserConfigurationException | SAXException | IOException e) {
throw new FileExportException(e, "pares xml error");
}
Element root = document.getDocumentElement();
NodeList elements = root.getElementsByTagName("cell");
List<ExportCell> exportCells = initElement(elements);
String fileName = "";
String exportType1 = "";
try {
fileName = ConfigParser.getNodeText(root, "fileName");
exportType1 = ConfigParser.getNodeText(root, "exportType");
} catch (FileImportException e) {
throw new FileExportException(e);
}
if (StringUtils.isEmpty(fileName)) {
throw new FileExportException("用於導出的xml文檔 <fileName> 為空");
}
if (StringUtils.isEmpty(exportType1) || !StringUtils.isNumeric(exportType1)) {
throw new FileExportException("用於導出的xml文檔 <exportType> 為空");
}
exportConfig.setFileName(fileName);
ExportType exportType = ExportType.getExportType(Integer.valueOf(exportType1));
if (exportType == null) {
throw new FileExportException("找不到相應的ExportType 解析xml得到的exportType 是" + exportType1);
}
exportConfig.setExportType(exportType);
exportConfig.setExportCells(exportCells);
return exportConfig;
}
這時我們得到一個ExportConfig對象如下：
public class ExportConfig extends BaseEntity {
private String fileName;//輸出的文件名
private ExportType exportType;//0 表示 excel, 1 表示csv
private List<ExportCell> exportCells;
4、添加要輸出到excel的list對象
List<Map> lists = new LinkedList<>();
for (int i = 0; i < 10; i++) {
Map<String, Object> maps = new HashMap<>();
maps.put("index", i);
maps.put("name", "張三" + i);
maps.put("age", Float.valueOf(i));
maps.put("sex", "男");
maps.put("date", new Date());
lists.add(maps);
}
在實際項目中map可以是具體的實體類對象比如Person,只要對象里面的字段跟person-export-config里的alias標簽對應上即可（如下圖所示）。
5、獲取ExportResult對象
具體代碼如下：
ExportResult exportResult = FileExportor.exportResult(exportConfig, lists);
將exportConfig對象跟要輸出到excel的lists對象傳入
public static ExportResult exportResult(ExportConfig exportConfig, List<?> data) throws FileExportException {
ExportType exportType = exportConfig.getExportType();
switch (exportType) {
case EXCEL2007:
Workbook workbook = new ExcelExportImpl().getExportResult(data, exportConfig.getExportCells());
ExportExcelResult exportExcelResult = new ExportExcelResult();
exportExcelResult.setWorkbook(workbook);
exportExcelResult.setFileName(exportConfig.getFileName());
return exportExcelResult;
case CSV:
StringBuilder stringBuilder = new CSVExportImpl().getExportResult(data, exportConfig.getExportCells());
ExportCSVResult exportCSVResult = new ExportCSVResult();
exportCSVResult.setResult(stringBuilder.toString());
exportCSVResult.setFileName(exportConfig.getFileName());
return exportCSVResult;
}
throw new FileExportException("找不到對應的export type, export type is " + exportType.getNumber());
}
6、最后將數據通過outputstream導出到excel
String fileName = "person統計" +".xlsx";
setResponseHeader(response, fileName);
OutputStream outputStream = response.getOutputStream();
exportResult.export(outputStream);
public void export(OutputStream outputStream) throws FileExportException{
try {
workbook.write(outputStream);
outputStream.close();
} catch (IOException e) {
throw new FileExportException("[Error occurred while export excel message is] " + e);
}
}
三、項目結構圖
四、運行效果圖
五、補充
本例子主要對poi導出excel進行了一個封裝，通過xml配置文件配置跟實體類一一對應的字段，可靈活配置，在實際項目中非常實用。