java导出文件之Excel（CSV）下并以流形式输出

<dependency>
		    <groupId>net.sourceforge.javacsv</groupId>
		    <artifactId>javacsv</artifactId>
		    <version>2.0</version>
		</dependency>  

@Test
    public void write(){
    try {
             // 创建CSV写对象
    List<Student> ls=new ArrayList<Student>();
             for (int i = 0; i <1000000; i++) {
            Student s=new Student();
            s.setName("小帅"+i);
            s.setAge(i);
            s.setScore("100"+i);
            s.setSex("男"+i);
            ls.add(s);
}
             //写入临时文件
             File tempFile = File.createTempFile("vehicle", ".csv");
             CsvWriter csvWriter = new CsvWriter(tempFile.getCanonicalPath(),',', Charset.forName("UTF-8"));
             // 写表头
             long s= System.currentTimeMillis();
             System.err.println();
             String[] headers = {"姓名","年龄","编号","性别"};
             csvWriter.writeRecord(headers);
             for (Student stu : ls) {
		csvWriter.write(stu.getName());
		csvWriter.write(stu.getAge()+"");
		csvWriter.write(stu.getScore());
		csvWriter.write(stu.getSex());
		csvWriter.endRecord();
		}
             csvWriter.close();
             long e=System.currentTimeMillis();

             System.err.println(e-s);;

   /**
    * 写入csv结束，写出流
    */
   java.io.OutputStream out = getResponse.getOutputStream();  
   byte[] b = new byte[10240];
   java.io.File fileLoad = new java.io.File(tempFile.getCanonicalPath());  
   getResponse.reset();
   getResponse.setContentType("application/csv");  
   getResponse.setHeader("content-disposition", "attachment; filename=vehicleModel.csv");  
	long fileLength = fileLoad.length();  
	String length1 = String.valueOf(fileLength);  
	getResponse.setHeader("Content_Length", length1);  
	java.io.FileInputStream in = new java.io.FileInputStream(fileLoad);  
	int n;  
	while ((n = in.read(b)) != -1) {  
  	 out.write(b, 0, n); //每次写入out1024字节 
	}  
  	 in.close();  
  	 out.close(); 

         } catch (IOException e) {
             e.printStackTrace();
         }
    }

网上找太多，眼逗看累了。自己写个简单的 

参考文章：http://blog.csdn.net/loongshawn/article/details/53423121

ps：version我本地只能用2.0；以流的形式写出游览器不用做操作文件会直接下载；

2：因为csvWriter不提供类似Poi的写入流  workbook.write(out);故在csv写入数据完之后，要手动把文件写入流；