Java生成CSV文件实例详解

本文实例主要讲述了Java生成CSV文件的方法，具体实现步骤如下：

1、新建CSVUtils.java文件：

package 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;
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 org.apache.commons.beanutils.BeanUtils;

/**
 * 文件操作
 */
public class CSVUtils {

  /**
   * 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));
      System.out.println("csvFile：" + csvFile);
      // UTF-8使正确读取分隔符"," 
      csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(
        csvFile), "UTF-8"), 1024);
      System.out.println("csvFileOutputStream：" + csvFileOutputStream);
      // 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();
          csvFileOutputStream.write((String) BeanUtils.getProperty(row,
            (String) propertyEntry.getKey()));
          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(HttpServletResponse response, String csvFilePath, String fileName)
                                                  throws IOException {
    response.setContentType("application/csv;charset=UTF-8");
    response.setHeader("Content-Disposition",
      "attachment; filename=" + URLEncoder.encode(fileName, "UTF-8"));

    InputStream in = null;
    try {
      in = new FileInputStream(csvFilePath);
      int len = 0;
      byte[] buffer = new byte[1024];
      response.setCharacterEncoding("UTF-8");
      OutputStream out = response.getOutputStream();
      while ((len = in.read(buffer)) > 0) {
        out.write(new byte[] { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF });
        out.write(buffer, 0, len);
      }
    } catch (FileNotFoundException e) {
      System.out.println(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", "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 = "c:/export/";
    String fileName = "文件导出";
    File file = CSVUtils.createCSVFile(exportData, map, path, fileName);
    String fileName2 = file.getName();
    System.out.println("文件名称：" + fileName2);
  }
}

2、调用createCSVFile方法生成CSV文件

String name = "银行退款数据";
List exportData = new ArrayList();
LinkedHashMap datamMap = null;
for (Iterator iterator = refundList.iterator(); iterator.hasNext();) {
   HashMap map = (HashMap) iterator.next();
   datamMap = new LinkedHashMap();
   datamMap.put("1", map.get("merOrderId"));
   datamMap.put("2",DateUtil.convertDateToString("yyyyMMdd", (Date) map.get("orderTime")));
   BigDecimal amount = (BigDecimal) map.get("amount");
   String amountString = amount.divide(new BigDecimal(10)).toPlainString();
   datamMap.put("3", amountString);
   datamMap.put("4", map.get("remark") != null ? map.get("remark") : "");
   exportData.add(datamMap);
}
 LinkedHashMap map = new LinkedHashMap();
 map.put("1", "订单号");
 map.put("2", "支付日期");
 map.put("3", "退货现金金额（整数金额 单位：分）");
 map.put("4", "退货原因");
 File file = CSVUtils.createCSVFile(exportData, map, filePath, name);//生成CSV文件
 fileName = file.getName();
 CSVUtils.exportFile(response, filePath + fileName, fileName);//下载生成的CSV文件