java导出csv文件
导出csv格式文件的本质是导出以逗号为分隔的文本数据
package com.huat.pojo; 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; /** * 文件操作 */ public class CsvUtil { public static boolean isEmpty(String str) { return str==null || str.trim().length()==0; } /** * 功能说明：获取UTF-8编码文本文件开头的BOM签名。 * BOM(Byte Order Mark)，是UTF编码方案里用于标识编码的标准标记。例：接收者收到以EF BB BF开头的字节流，就知道是UTF-8编码。 * @return UTF-8编码文本文件开头的BOM签名 */ public static String getBOM() { byte b[] = {(byte)0xEF, (byte)0xBB, (byte)0xBF}; return new String(b); } /** * 生成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.mkdirs(); } //定义文件名格式并创建 csvFile =new File(outPutPath+fileName+".csv"); file.createNewFile(); // UTF-8使正确读取分隔符"," //如果生产文件乱码，windows下用gbk，linux用UTF-8 csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream( csvFile), "gbk"), 1024); //写入前段字节流，防止乱码 // csvFileOutputStream.write(getBOM()); // 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(); String str=row!=null?((String)((Map)row).get( propertyEntry.getKey())):""; if(CsvUtil.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; } /** * 生成并下载csv文件 * @param response * @param exportData * @param map * @param outPutPath * @param fileName * @throws IOException */ @SuppressWarnings("rawtypes") public static void exportDataFile(HttpServletResponse response,List exportData, LinkedHashMap map, String outPutPath,String fileName) throws IOException{ File csvFile = null; BufferedWriter csvFileOutputStream = null; try { File file = new File(outPutPath); if (!file.exists()) { file.mkdirs(); } //定义文件名格式并创建 csvFile =new File(outPutPath+fileName+".csv"); if(csvFile.exists()){ csvFile.delete(); } csvFile.createNewFile(); // UTF-8使正确读取分隔符"," //如果生产文件乱码，windows下用gbk，linux用UTF-8 OutputStreamWriter osw=new OutputStreamWriter(fos, "UTF-8"); csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(csvFile), "UTF-8"), 1024); //写入前段字节流，防止乱码 csvFileOutputStream.write(getBOM()); // 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(); String str=row!=null?((String)((Map)row).get( propertyEntry.getKey())):""; if(CsvUtil.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, 0, len); } out.close(); } catch (FileNotFoundException e) { } finally { if (in != null) { try { in.close(); } catch (Exception e) { throw new RuntimeException(e); } } } } /** * 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; } } } } } /** * 测试数据 * @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", "学习"); row1.put("2", "事件"); row1.put("3", "咋整"); exportData.add(row1); row1 = new LinkedHashMap<String, String>(); row1.put("1", "嘿嘿"); row1.put("2", "哈哈"); row1.put("3", "呵呵"); exportData.add(row1); LinkedHashMap map = new LinkedHashMap(); //设置列名 map.put("1", "RULE_ID"); map.put("2", "LABELS"); map.put("3", "RULE NAME"); //这个文件上传到路径，可以配置在数据库从数据库读取，这样方便一些！ String path = "c:/pearl/"; //文件名=生产的文件名称+时间戳 String fileName = "文件导出"; File file = CsvUtil.createCSVFile(exportData, map, path, fileName); String fileName2 = file.getName(); System.out.println("文件名称：" + fileName2); } }
