Penjelasan detail tentang contoh pembuatan file CSV di Java

Contoh dalam artikel ini terutama menjelaskan metode pembuatan file CSV di Java. Langkah-langkah implementasi spesifiknya adalah sebagai berikut:

1. Buat file CSVUtils.java baru:

 paket com.saicfc.pmpf.internal.manage.utils;import java.io.BufferedWriter;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java .io.IOException;impor java.io.InputStream;impor java.io.OutputStream;impor java.io.OutputStreamWriter;impor java.net.URLEncoder;impor java.util.ArrayList;impor java.util.Iterator;impor java.util.LinkedHashMap;impor java.util.List;impor java .util.Map;import javax.servlet.http.HttpServletResponse;import org.apache.commons.beanutils.BeanUtils;/** * Operasi file*/public class CSVUtils { /** * Hasilkan sebagai file CVS* @param eksporData * Daftar sumber data * @peta param * Daftar peta header file csv * @param outPutPath * Jalur file * @param fileName * Nama file * @return */ @SuppressWarnings("rawtypes") File statis publik createCSVFile(Daftar data ekspor, peta LinkedHashMap, String outPutPath, String fileName) { File csvFile = null; } } //Tentukan format nama file dan buat csvFile = File.createTempFile(fileName, ".csv", File baru(outPutPath)); System.out.println("csvFile: " + csvFile); // UTF-8 memungkinkan pembacaan pembatas yang benar "," csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream) (csvFile), "UTF-8"), 1024); System.out.println("csvFileOutputStream: " + csvFileOutputStream); // Tulis header file untuk (Iterator propertyIterator = map.entrySet().iterator(); propertyIterator.hasNext();) { java.util.Map propertyEntry = (java.util.Map.Entry) propertyIterator.next(); csvFileOutputStream .write(""" + (String) propertyEntry.getValue() != null ? (String) propertyEntry .getValue() : "" + """); if (propertyIterator.hasNext()) { csvFileOutputStream.write(","); } } csvFileOutputStream.newLine(); //Menulis konten file untuk (Iterator iterator = eksporData.iterator(); iterator.hasNext();) { Baris objek = (Objek) iterator.next(); untuk (Iterator propertyIterator = map.entrySet().iterator(); propertyIterator .hasNext();) { java.util.Map.Entry propertyEntry = (java.util.Map.Entry) propertyIterator .next(); csvFileOutputStream.write((String) BeanUtils.getProperty(baris, (String) propertyEntry.getKey())); jika (propertyIterator.hasNext()) { csvFileOutputStream.write("," } } if (iterator.hasNext()) { csvFileOutputStream.newLine( ); } } csvFileOutputStream.flush(); e.printStackTrace(); } akhirnya { coba { csvFileOutputStream.close(); } tangkap (IOException e) { e.printStackTrace(); } kembalikan csvFile; * Jalur file * @param nama file * Nama file * @throws IOException */ public static void eksporFile(Respon HttpServletResponse, String csvFilePath, String fileName) melempar IOException { respon.setContentType("application/csv;charset=UTF-8"); respon.setHeader("Content-Disposition", "attachment; filename=" + URLEncoder. encode(namafile, "UTF-8")); InputStream di = null; coba { di = baru FileInputStream(csvFilePath); int len ​​= 0; byte[] buffer = byte baru[1024]; respon.setCharacterEncoding("UTF-8"); baca( buffer)) > 0) { keluar.tulis(byte baru[] { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF }); keluar.tulis(buffer, 0, len); } } catch (FileNotFoundException e) { System.out.println(e); akhirnya { jika (dalam != null) { coba { masuk.close() ; } catch (Pengecualian e) { throw new RuntimeException(e) } } } } /** * Hapus semua file di bawah filePath di direktori ini * @param filePath); * Jalur direktori file*/ public static void deleteFiles(String filePath) { File file = File baru(filePath); if (file.exists()) { File[] files = file.listFiles(); ; i < files.length; i++) { if (files[i].isFile()) { files[i].delete(); filePath * jalur direktori file * @param nama file * nama file */ public static void deleteFile(String filePath, String fileName) { File file = File baru(filePath); .listFiles(); untuk (int i = 0; i < file.panjang; i++) { jika (file[i].isFile()) { jika (file[i].getName().equals(fileName)) { files[i].delete(); kembali; } } } } } /** * Data pengujian* @param args */ @SuppressWarnings({ "tipe mentah ", "tidak dicentang" }) public static void main(String[] args) { Daftar eksporData = new ArrayList<Map>(); Peta baris1 = baru LinkedHashMap<String, String>(); baris1.put("1", "11"); baris1.put("2", "12"); baris1.put("3", "13"); put("4", "14"); eksporData.tambahkan(baris1); LinkedHashMap baru<String, String>(); baris1.put("2", "22"); baris1.put("3", "23"); baris1.put("4", "24"); LinkedHashMap(); map.put("1", "Kolom pertama"); map.put("2", "Kolom kedua"); map.put("4", "Kolom keempat"); Jalur string = "c:/export/"; String namafile = "Ekspor file"; File file = CSVUtils.createCSVFile(data ekspor, peta, jalur, Nama file String namafile2 = file.getName(); System.out.println("Nama file: " + Namafile2 }}

2. Panggil metode createCSVFile untuk menghasilkan file CSV

 String name = "Data pengembalian dana bank";Daftar eksporData = new ArrayList();LinkedHashMap datamMap = null;for (Iterator iterator = refundList.iterator(); iterator.hasNext();) { HashMap map = (HashMap) iterator berikutnya (); datamMap = new LinkedHashMap(); datamMap.put("1", map.get("merOrderId")); datamMap.put("2",DateUtil.convertDateToString("yyyyMMdd", (Tanggal) map.get("orderTime"))); "jumlah"); String jumlahString = jumlah.divide(New BigDecimal(10)).toPlainString(); datamMap.put("3", amountString); datamMap.put("4", map.get("komentar") != null ? map.get("komentar") : ""); ;} LinkedHashMap map = new LinkedHashMap(); map.put("1", "Nomor Pesanan"); map.put("2", "Tanggal Pembayaran"); map.put("3", "Jumlah pengembalian uang tunai (satuan bilangan bulat: sen)"); map.put("4", "Alasan pengembalian File file = CSVUtils.createCSVFile(exportData, map, filePath, nama );//Buat file CSV fileName = file.getName();