Java实现导出数据到csv文件的示例代码

项目中很多情况会遇到需要导出数据到csv文件，代码如下：

package com.elane.common.utils.poi;
 
import Javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.util.List;
 
public class CandroidSVUtil {
    /**
     * 导出csv文件
     * @param response 导出文件需要的设置在response 中设置好
     * @param head 英文逗号分隔的数据表头
     * @param dataList 英文逗号分隔的数据
     * @param filename 导出后的文件名称
     */
    public static void createCSVFile(HttpServletResponse response, List<String> head, List<String> dataList,
                                     String filename) {
        File csvFile = null;
        Bufferedwriter csvWtriter = null;
        InputStream in = null;
        OutputStream out = null;
        try {
            csvFile=new File(filename);
 
            // GB2312使正确读取分隔符","
            FileOutputStream fileOutputStream=new FileOutputStream(csvFile);
            OutputStreamWriter outputStreamWriter=new OutputStreamWriter(fileOutputStream);
//            outputStreamWriter.write(new String(new byte[]{(byte) 0xEF, (byte) 0xBB, (bythttp://www.devze.come) 0xBF}));
            csvWtriter = new BufferedWriter(outputStreamWriter);
 
            // 写入文件头部
            if (head.size()>0){
                csvWtriter.write(head.get(0));
                csvWtriter.newLine();
            }
 
            // 写入文件内容
            for (String item:dataList){
                csvWtriter.write(item);
                csvWtriter.newLine();
            }
            csvWtriter.flush();
 
            in = new FileInputStream(csvFile);
            int len = 0;
            byte[] buffer = new byte[1024*1024*5];
            out = response.getOutputStream();
 
            // 设置此response为文件下载响应
            response.setContentType("application/csv;charset=UTF-8");
            response.setHeader("Content-Disposition",
                    "attachment; filename=" + URLEncoder.encode(csvFile.getName(), "UTF-8"));
            response.setCharacterEncoding("UTF-8");
            // 先写UTF-8文件标志头
            out.write(new byte[] { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF });
            while ((len = in.read(buffer)) > 0) {
                out.write(buffer, 0, len);
            }
            out.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (in != null) {
                    in.close();
                }
                if (out != null) {
                    out.close();
                }
                if (csvFile != null) {
                    csvFile.delete();
                }
                if (csvWtriter != null) {
                    csvWtriter.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
 
    /**
     * 保存至csv文件，不导出
     * @param fileName  保存的文件名
     * @param tempDir 文件保存路径
     * @param head 英文逗号分隔的数据表头
     * @param dataList 英文逗号分隔的数据
     */
    public static void SaveTxtFile(String fileName, String tempDir,List<String> head,List<String> dataList) {
        String filePath=tempDir+"/"+fileName;
        try{
            FileOutputStream fileOutputStream=new FileOutputStream(filePath);
            OutputStreamWriter outputStreamWriter=new OutputStreamWriter(fileOutputStream);
            outputStreamWriter.write(new String(new byte[]{(byte) 0xEF, (byte) 0xBB, (byte) 0xBF}));
            BufferedWriter writer=new BufferedWriter(outputStreamWriter);
            writer.write(head.get(0));
            writer.newLine();
            for (String item:dataList){
                writer.write(item));
                writer.newLine();
            }
            writer.close();
        }
        catch (IOException e){
            System.err.println(e.getMessage());
        }
    }
}

方法补充

1.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.HttpServletRespwww.devze.comonse;  

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"hnKBnHM,"  
      //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+"\"";
         编程客栈         }
              }
              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);  
  }  
}  

2.Java实现Csv文件导入导出

导入

 	/**
	 * 读取crv文件并转换成List
	 *
	 * @param separator crv文件分隔符
	 * @param file      待读取文件
	 * @return crv对象list
	 */
	public static <T> List<T> read(String separator, File file, Class<T> clazz) {
		List<T> result = Collections.emptyList();
		try {
			BeanListProcessor<T> rowprocessor = new BeanListProcessor<>(clazz);
			//设置分隔符
			CsvFormat csvFormat = new CsvFormat();
			csvFormat.setDelimiter(separator);

			CsvParserSettings parserSettings = new CsvParserSettings();
			parserSettings.setProcessor(rowProcessor);
			parserSettings.setFormat(csvFormat);

			CsvParser parser = new CsvParser(parserSettings);
			InputStream in = Files.newInputStream(file.toPath());
			parser.parse(in);
			//逐行读取
			result = rowProcessor.getBeans();
		} catch (Exception e) {
            log.error("Import csv file failed. message: ", e);
		}
		return result;
	}

测试

	@Getter
	@Setter
	@NoArgsConstructor
	@AllArgsConstructor
	@ToString
	public static class User implements Serializable {
		@Parsed(filed = "name")
        private String name;
        @Parsed(filed = "age")
        private Integer age;
    }

	public static void main(String[] args) {

		File file = new File("E:\\test.csv");
		List<User> users = CsvUtil.read(",", file, User.class);
		users.forEach(System.out::println);

	}

导出

直接创建一个工具类使用，把导入导出方法粘贴进去使用即可

    /**
     * csv文件导出
     *
     * @param data      导出数据
     * @param file      导出目的文件
     * @param separator 分割符
     * @param clazz     导出对象
     * @param <T>       数据对象泛型
     */
    public static <T> void export(Collection<T> data, File file, String separator, Class<T> clazz) {
        try {
            CsvWriterSettings settings = new CsvWriterSettings();
            //设置分隔符
            CsvFormat csvFormat = new CsvFormat();
            csvFormat.setDelimiter(separator);
            settings.setFormat(csvFormat);
            settings.setHeaderWritingEnabled(false);
            settings.setRowWriterProcessor(new BeanWriterProcessor<>(clazz));
            CsvWriter writer = new CsvWriter(Files.newOutputStream(file.toPath()), "utf-8", settings);
            // 写入header
            writer.writeHeaders(settings.getHeaders());
            data.forEach(writer::processRecord);
            writer.close();
        } catch (Exception e) {
            log.error("export .csv file failed. message.", e);
        }
    }

测试

    @Getter
    @Setter
    @NoArgsConstructor
    @AllArgsConstructor
	@ToString
    public static class User implements Serializable {
        @Parsed(filed = "name")
        private String name;
        @Parsed(filed = "age")
        private Integer age;
    }

    public static void main(String[] args) {
        User user1 = new User("张三", 18);
        User user2 = new User("李四", 19);
        List<User> users = Arrays.asList(user1, user2);
        File file = new File("E:\\test.csv");
        CsvUtil.export(users, file, ",", User.class);
    }

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