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);  
  }  
}