java导出csv格式文件

导出csv格式文件的本质是导出以逗号为分隔的文本数据

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;

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

    /**
    * 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), "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(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
          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(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, 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", "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();  

    //设置列名
    map.put("1", "第一列名称");
    map.put("2", "第二列名称");
    map.put("3", "第三列名称");
    map.put("4", "第四列名称");
    //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 = "E:/";  

   //文件名=生产的文件名称+时间戳
    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);
  }
}  

完工。