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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