java匯出csv格式檔案的方法
阿新 • • 發佈:2021-01-04
本文例項為大家分享了java匯出csv格式檔案的具體程式碼,供大家參考,具體內容如下
匯出csv格式檔案的本質是匯出以逗號為分隔的文字資料
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.net.URLEncoder; import java.util.ArrayList; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; import javax.servlet.http.HttpServletResponse; import com.alibaba.druid.util.StringUtils; /** * 檔案操作 */ public class CSVUtils { /** * 功能說明:獲取UTF-8編碼文字檔案開頭的BOM簽名。 * BOM(Byte Order Mark),是UTF編碼方案裡用於標識編碼的標準標記。例:接收者收到以EF BB BF開頭的位元組流,就知道是UTF-8編碼。 * @return UTF-8編碼文字檔案開頭的BOM簽名 */ public static String getBOM() { byte b[] = {(byte)0xEF,(byte)0xBB,(byte)0xBF}; return new String(b); } /** * 生成CVS檔案 * @param exportData * 源資料List * @param map * csv檔案的列表頭map * @param outPutPath * 檔案路徑 * @param fileName * 檔名稱 * @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.mkdirs(); } //定義檔名格式並建立 csvFile =new File(outPutPath+fileName+".csv"); file.createNewFile(); // UTF-8使正確讀取分隔符"," //如果生產檔案亂碼,windows下用gbk,linux用UTF-8 csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream( csvFile),"UTF-8"),1024); //寫入前段位元組流,防止亂碼 csvFileOutputStream.write(getBOM()); // 寫入檔案頭部 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(); // 寫入檔案內容 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(); String str=row!=null?((String)((Map)row).get( propertyEntry.getKey())):""; if(StringUtils.isEmpty(str)){ str=""; }else{ str=str.replaceAll("\"","\"\""); if(str.indexOf(",")>=0){ str="\""+str+"\""; } } csvFileOutputStream.write(str); 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; } /** * 生成並下載csv檔案 * @param response * @param exportData * @param map * @param outPutPath * @param fileName * @throws IOException */ @SuppressWarnings("rawtypes") public static void exportDataFile(HttpServletResponse response,List exportData,String fileName) throws IOException{ File csvFile = null; BufferedWriter csvFileOutputStream = null; try { File file = new File(outPutPath); if (!file.exists()) { file.mkdirs(); } //定義檔名格式並建立 csvFile =new File(outPutPath+fileName+".csv"); if(csvFile.exists()){ csvFile.delete(); } csvFile.createNewFile(); // UTF-8使正確讀取分隔符"," //如果生產檔案亂碼,windows下用gbk,linux用UTF-8 csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(csvFile),1024); //寫入前段位元組流,防止亂碼 csvFileOutputStream.write(getBOM()); // 寫入檔案頭部 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(); // 寫入檔案內容 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(); String str=row!=null?((String)((Map)row).get( propertyEntry.getKey())):""; if(StringUtils.isEmpty(str)){ str=""; }else{ str=str.replaceAll("\"","\"\""); if(str.indexOf(",")>=0){ str="\""+str+"\""; } } csvFileOutputStream.write(str); 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(); } } InputStream in = null; try { in = new FileInputStream(outPutPath+fileName+".csv"); int len = 0; byte[] buffer = new byte[1024]; OutputStream out = response.getOutputStream(); response.reset(); response.setContentType("application/csv;charset=UTF-8"); response.setHeader("Content-Disposition","attachment; filename=" + URLEncoder.encode(fileName+".csv","UTF-8")); response.setCharacterEncoding("UTF-8"); while ((len = in.read(buffer)) > 0) { out.write(new byte[] { (byte) 0xEF,(byte) 0xBB,(byte) 0xBF }); out.write(buffer,len); } out.close(); } catch (FileNotFoundException e) { } finally { if (in != null) { try { in.close(); } catch (Exception e) { throw new RuntimeException(e); } } } } /** * 刪除該目錄filePath下的所有檔案 * @param filePath * 檔案目錄路徑 */ 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(); } } } } /** * 刪除單個檔案 * @param filePath * 檔案目錄路徑 * @param fileName * 檔名稱 */ 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; } } } } } /** * 測試資料 * @param args */ @SuppressWarnings({ "rawtypes","unchecked" }) public static void main(String[] args) { 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,"21"); row1.put("2","22"); row1.put("3","23"); row1.put("4","24"); exportData.add(row1); LinkedHashMap map = new LinkedHashMap(); //設定列名 map.put("1","第一列名稱"); map.put("2","第二列名稱"); map.put("3","第三列名稱"); map.put("4","第四列名稱"); //這個檔案上傳到路徑,可以配置在資料庫從資料庫讀取,這樣方便一些! String path = "E:/"; //檔名=生產的檔名稱+時間戳 String fileName = "檔案匯出"; File file = CSVUtils.createCSVFile(exportData,map,path,fileName); String fileName2 = file.getName(); System.out.println("檔名稱:" + fileName2); } }
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