java导出csv格式文件的方法

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); 
 } 
}