Apache POI-Excel入门与实战

<dependency>  
    <groupId>org.apache.poi</groupId>  
    <artifactId>poi</artifactId>  
    <version>3.16</version>  
</dependency>  
<dependency>  
    <groupId>org.apache.poi</groupId>  
    <artifactId>poi-ooxml</artifactId>  
    <version>3.16</version>  
</dependency>

二、Apache POI-Excel 入门案例

2.1 写入Excel文件

/**  
 * ApachePOI 测试类  
 */  
public class ApachePOITest {  
  
    /**  
     * 读取 Excel 文件  
     */  
    public static void write() {  
        // 在内存中创建一个 Excel 文件  
        XSSFWorkbook excel = new XSSFWorkbook();  
        // 创建一个工作表sheet  
        XSSFSheet sheet = excel.createSheet("info");  
        //在sheet中添加表头第1行,RowNum是从0开始的  
        XSSFRow row = sheet.createRow(1);  
        row.createCell(1).setCellValue("姓名");  
        row.createCell(2).setCellValue("年龄");  
  
        //创建一个新的row  
        XSSFRow row2 = sheet.createRow(2);  
        //在row中创建单元格  
        row2.createCell(1).setCellValue("张三");  
        row2.createCell(2).setCellValue("20");  
  
        //创建一个新的row  
        sheet.createRow(3).createCell(1).setCellValue("李四");  
        sheet.getRow(3).createCell(2).setCellValue("30");  
  
        //将excel写入到文件中  
        try {  
            //通过文件输出流将内存中的excel写入到文件中  
            FileOutputStream fileOutputStream = new FileOutputStream("E:" + File.separator + "POITest.xlsx");  
            excel.write(fileOutputStream);  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
  
    }  
  
    public static void main(String[] args) {  
        write();  
    }  
	//关闭流
	excel.close
}

2.2 读取文件

/**  
 * 读取 Excel 文件  
 */  
public  static  void read() throws IOException {  
    //通过文件输入流读取文件  
    FileInputStream fileInputStream = new FileInputStream("E:" + File.separator + "POITest.xlsx");  
    XSSFWorkbook excel = new XSSFWorkbook(fileInputStream);  
    //读取第一个工作表  
    //XSSFSheet sheet = excel.getSheet("info");  
    XSSFSheet sheetAt = excel.getSheetAt(0);  
  
    //获取最后一行的行号  
    int lastRowNum = sheetAt.getLastRowNum();  
    //从第二行开始读取数据  
    for (int i = 1; i <= lastRowNum; i++) {  
        //获取当前行  
        XSSFRow row = sheetAt.getRow(i);  
        //获取当前行的最后一个单元格的编号  
        short lastCellNum = row.getLastCellNum();  
  
        //遍历所有的单元格，从第二个单元格开始  
        for (int j = 1; j < lastCellNum; j++) {  
            System.out.print(row.getCell(j) + "\t");  
        }  
        System.out.println();  
    }  
  
    //关闭流  
    excel.close();  
    fileInputStream.close();  
}

四、Apache POI实战

1.通过读取Excel方法获取一个城市对应的地址编号

2.通过写入Excel方法将一个城市未来的天气情况写入Excel表格中

4.1 创建一个获取天气的API

这里使用高德地图的天气API

创建应用，获取需要的key

4.2高德天气请求API与响应结果

请求API

由于这里的天气需要用到城市编码表，所以先下载好对应的城市编码表格

下载好后内容如下

返回的Response

APIFOX工具（也可以用postman）测试：

API地址：https://restapi.amap.com/v3/weather/weatherInfo?parameters

成功返回了数据说明前面一切操作都是对的。而后端访问则通过HttpClient形式访问

4.2 后端访问API获取数据

引入依赖

<dependency>  
    <groupId>org.apache.httpcomponents</groupId>  
    <artifactId>httpclient</artifactId>  
    <version>4.5.13</version>  
</dependency>

<dependency>
	<groupId>com.alibaba</groupId>
	<artifactId>fastjson</artifactId>
	<version>1.2.76</version>
</dependency>

有了API和城市编码表格，现在我们只需要在用户输入对应的城市或者区域的时候，遍历表格进行读取，如果有对应的区则返回adcode

测试类：

	@Test
	void WeatherTest() throws URISyntaxException, IOException {

// TODO:这里的key需要引用自己的
		String key = "xxxxxxx";
		String city = "110101";

		CloseableHttpClient httpClient = HttpClients.createDefault();

		URIBuilder uriBuilder = new URIBuilder("https://restapi.amap.com/v3/weather/weatherInfo");
		uriBuilder.addParameter("key", key);
		uriBuilder.addParameter("city", city);

		HttpGet httpGet = new HttpGet(uriBuilder.build());

		try (CloseableHttpResponse response = httpClient.execute(httpGet)) {
			int statusCode = response.getStatusLine().getStatusCode();

			if (statusCode == 200) {
				HttpEntity entity = response.getEntity();
				String result = EntityUtils.toString(entity, "UTF-8");
				System.out.println(result);
			} else {
				System.out.println("Failed to retrieve data, status code: " + statusCode);
			}
		}
		httpClient.close();
	}

}

4.3 通过获取地方名称获取AdCode编码

	@Test
	void AdCodeQuery() throws IOException {

//		TODO：这里输入下载好的地址对照表
		String AMapFilePath = "E:\\AMap_adcode_citycode.xlsx";
//		需要查询的地址
		String address = "北京市";


		FileInputStream fileInputStream = new FileInputStream(AMapFilePath);
		XSSFWorkbook workbook = new XSSFWorkbook(fileInputStream);

		XSSFSheet sheetAt = workbook.getSheetAt(0);

		for (int i=1;i<sheetAt.getLastRowNum();i++){
			XSSFCell cell = sheetAt.getRow(i).getCell(0);
			String stringCellValue = cell.getStringCellValue();

			if (stringCellValue.equals(address)){
				XSSFCell cell1 = sheetAt.getRow(i).getCell(1);
				String adcode = cell1.getStringCellValue();
				System.out.println("查询到地区编号为"+adcode);
			}
		}

	}

4.4 使用Apache POI包装数据并将预测结果输出到Excel表格中

	@Test
	void WeatherTest() throws URISyntaxException, IOException {


// TODO:这里的key需要引用自己的
		String key = "xxxxxxx";
		String city = "110101";
		String extensions = "all";

		CloseableHttpClient httpClient = HttpClients.createDefault();

		URIBuilder uriBuilder = new URIBuilder("https://restapi.amap.com/v3/weather/weatherInfo");
		uriBuilder.addParameter("key", key);
		uriBuilder.addParameter("city", city);
		uriBuilder.addParameter("extensions",extensions);

		HttpGet httpGet = new HttpGet(uriBuilder.build());

		try (CloseableHttpResponse response = httpClient.execute(httpGet)) {
			int statusCode = response.getStatusLine().getStatusCode();

			if (statusCode == 200) {
				HttpEntity entity = response.getEntity();
				String jsonString = EntityUtils.toString(entity, "UTF-8");

//				通过POI写入文件
				
				// 将JSON字符串解析为Java对象
				Map<String, Object> map = JSON.parseObject(jsonString, new TypeReference<Map<String, Object>>() {});

				// 获取casts列表
				List<Map<String, Object>> casts = (List<Map<String, Object>>) ((List<Map<String, Object>>) map.get("forecasts")).get(0).get("casts");
				
				// 创建Excel工作簿
				Workbook workbook = new XSSFWorkbook();
				Sheet sheet = workbook.createSheet("Weather Forecasts");
				
				// 创建标题行
				Row headerRow = sheet.createRow(0);
				CellStyle headerStyle = workbook.createCellStyle();
				headerStyle.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.getIndex());
				headerStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
				
				// 写入标题
				int cellIndex = 0;

				String[] columnHeaders = {"date", "week", "dayweather", "nightweather", "daytemp", "nighttemp", "daywind", "nightwind", "daypower", "nightpower", "daytemp_float", "nighttemp_float"};
				for (String columnHeader : columnHeaders) {
					Cell cell = headerRow.createCell(cellIndex++);
					cell.setCellValue(columnHeader);
					cell.setCellStyle(headerStyle);
				}

				// 创建数据行
				int rowIndex = 1;

				for (Map<String, Object> cast : casts) {
					Row row = sheet.createRow(rowIndex++);
					// 写入数据
					cellIndex = 0;
					for (String columnHeader : columnHeaders) {
						Cell cell = row.createCell(cellIndex++);
						cell.setCellValue(cast.get(columnHeader).toString());
					}
				}
				// 写入Excel文件
				try (FileOutputStream fileOut = new FileOutputStream("WeatherForecasts.xlsx")) {
					workbook.write(fileOut);
				}
				// 关闭工作簿
				workbook.close();

			} else {
				System.out.println("Failed to retrieve data, status code: " + statusCode);
			}
		}
		httpClient.close();
	}

原文地址:https://blog.csdn.net/dogxixi/article/details/140605232 本文来自互联网用户投稿，该文观点仅代表作者本人，不代表本站立场。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如若转载，请注明出处：https://www.suanlizi.com/kf/1815493533604384768.html 如若内容造成侵权/违法违规/事实不符，请联系《酸梨子》网邮箱：1419361763@qq.com进行投诉反馈，一经查实，立即删除！

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