Java生成CSV文件实例详解

本是古典何须时尚 2024-02-18 17:22 29阅读 0赞

生产CSV文件，一般用于对账，记录操作快照等，遇到问题方便查找原因！

Java生成CSV文件的方法，具体实现步骤如下：

在你自己的包下，创建CSVUtils.java文件：

package com.aspire.aplus.util;  
  
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","  
//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);   
 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();

//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 = "D:/reateCSVFile/";

//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);   
 \}   
\}

生成文件如下图：

![Image 1][]![Center][]

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[Image 1]: 
[Center]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/aaf398be065741aeb1365ec6c13c9c04.png