Java生成CSV文件简单操作实例
CSV是逗号分隔文件(Comma Separated Values)的首字母英文缩写，是一种用来存储数据的纯文本格式，通常用于电子表格或数据库软件。在 CSV文件中，数据“栏”以逗号分隔，可允许程序通过读取文件为数据重新创建正确的栏结构，并在每次遇到逗号时开始新的一栏。如：
1,张三,男 2,李四,男 3,小红,女
Java生成CSV文件（创建与导出封装类）
package com.yph.omp.common.util; import java.io.BufferedWriter; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.util.ArrayList; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.beanutils.BeanUtils; import org.junit.Test; /** * Java生成CSV文件 */ public class CSVUtil { /** * 生成为CVS文件 * * @param exportData * 源数据List * @param map * csv文件的列表头map * @param outPutPath * 文件路径 * @param fileName * 文件名称 * @return */ @SuppressWarnings("rawtypes") public static File createCSVFile(List exportData, LinkedHashMap map, String outPutPath, String fileName) { File csvFile = null; BufferedWriter csvFileOutputStream = null; try { File file = new File(outPutPath); if (!file.exists()) { file.mkdir(); } // 定义文件名格式并创建 csvFile = File.createTempFile(fileName, ".csv", new File(outPutPath)); // UTF-8使正确读取分隔符"," csvFileOutputStream = new BufferedWriter(new OutputStreamWriter( new FileOutputStream(csvFile), "GBK"), 1024); // 写入文件头部 for (Iterator propertyIterator = map.entrySet().iterator(); propertyIterator .hasNext();) { java.util.Map.Entry propertyEntry = (java.util.Map.Entry) propertyIterator .next(); csvFileOutputStream .write("\"" + (String) propertyEntry.getValue() != null ? (String) propertyEntry .getValue() : "" + "\""); if (propertyIterator.hasNext()) { csvFileOutputStream.write(","); } } csvFileOutputStream.newLine(); // 写入文件内容 for (Iterator iterator = exportData.iterator(); iterator.hasNext();) { Object row = (Object) iterator.next(); for (Iterator propertyIterator = map.entrySet().iterator(); propertyIterator .hasNext();) { java.util.Map.Entry propertyEntry = (java.util.Map.Entry) propertyIterator .next();
/*-------------------------------*/ //以下部分根据不同业务做出相应的更改 StringBuilder sbContext = new StringBuilder(""); if (null != BeanUtils.getProperty(row,(String) propertyEntry.getKey())) { if("证件号码".equals(propertyEntry.getValue())){ //避免：身份证号码 ，读取时变换为科学记数 - 解决办法：加 \t(用Excel打开时，证件号码超过15位后会自动默认科学记数) sbContext.append(BeanUtils.getProperty(row,(String) propertyEntry.getKey()) + "\t"); }else{ sbContext.append(BeanUtils.getProperty(row,(String) propertyEntry.getKey())); } } csvFileOutputStream.write(sbContext.toString()); /*-------------------------------*/ if (propertyIterator.hasNext()) { csvFileOutputStream.write(","); } } if (iterator.hasNext()) { csvFileOutputStream.newLine(); } } csvFileOutputStream.flush(); } catch (Exception e) { e.printStackTrace(); } finally { try { csvFileOutputStream.close(); } catch (IOException e) { e.printStackTrace(); } } return csvFile; } /** * 下载文件 * * @param response * @param csvFilePath * 文件路径 * @param fileName * 文件名称 * @throws IOException */ public static void exportFile(HttpServletRequest request, HttpServletResponse response, String csvFilePath, String fileName) throws IOException { response.setCharacterEncoding("UTF-8"); response.setContentType("application/csv;charset=GBK"); response.setHeader("Content-Disposition", "attachment; filename=" + new String(fileName.getBytes("GB2312"), "ISO8859-1")); InputStream in = null; try { in = new FileInputStream(csvFilePath); int len = 0; byte[] buffer = new byte[1024]; OutputStream out = response.getOutputStream(); while ((len = in.read(buffer)) > 0) { out.write(buffer, 0, len); } } catch (FileNotFoundException e1) { System.out.println(e1); } finally { if (in != null) { try { in.close(); } catch (Exception e1) { throw new RuntimeException(e1); } } } } /** * 删除该目录filePath下的所有文件 * * @param filePath * 文件目录路径 */ public static void deleteFiles(String filePath) { File file = new File(filePath); if (file.exists()) { File[] files = file.listFiles(); for (int i = 0; i < files.length; i++) { if (files[i].isFile()) { files[i].delete(); } } } } /** * 删除单个文件 * * @param filePath * 文件目录路径 * @param fileName * 文件名称 */ public static void deleteFile(String filePath, String fileName) { File file = new File(filePath); if (file.exists()) { File[] files = file.listFiles(); for (int i = 0; i < files.length; i++) { if (files[i].isFile()) { if (files[i].getName().equals(fileName)) { files[i].delete(); return; } } } } } @SuppressWarnings({ "unchecked", "rawtypes" }) @Test public void createFileTest() { List exportData = new ArrayList<Map>(); Map row1 = new LinkedHashMap<String, String>(); row1.put("1", "11"); row1.put("2", "12"); row1.put("3", "13"); row1.put("4", "14"); exportData.add(row1); row1 = new LinkedHashMap<String, String>(); row1.put("1", "21"); row1.put("2", "22"); row1.put("3", "23"); row1.put("4", "24"); exportData.add(row1); LinkedHashMap map = new LinkedHashMap(); map.put("1", "第一列"); map.put("2", "第二列"); map.put("3", "第三列"); map.put("4", "第四列"); String path = "d:/export"; String fileName = "文件导出"; File file = CSVUtil.createCSVFile(exportData, map, path, fileName); String fileNameNew = file.getName(); String pathNew = file.getPath(); System.out.println("文件名称：" + fileNameNew ); System.out.println("文件路径：" + pathNew ); } }
//注：BeanUtils.getProperty(row,(String) propertyEntry.getKey()) + "\t" ，只为解决数字格式超过15位后，在Excel中打开展示科学记数问题。
