java导出csv格式文件的方法

本文实例为大家分享了java导出csv格式文件的具体代码，供大家参考，具体内容如下

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);
 }
} 

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