java导出文件之Excel（CSV）下并以流形式输出

痛定思痛。 2022-06-12 01:52 310阅读 0赞

<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

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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；

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[Center]: /images/20220612/d8cc9cabb94b47b8b27c8bf091a8c780.png
[Center 1]: /images/20220612/01d133a462e7401593f1ebf58b644204.png