java生成读取csv_Java Web读取/输出csv文件

简单实现

1、页面上传csv解析成数组；

2、后台字符串生成csv文件并在页面输出下载。

IDEA新建的SpringBoot Demo project

html页面:

控制器

package com.example.demo.controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.bind.annotation.RestController;

import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.*;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

@RestController

@RequestMapping("/file")

public class FileController {

/**

* 导入csv文件

* @param file

* @param request

* @param response

* @throws UnsupportedEncodingException

*/

@RequestMapping(value = "/uploadFile", method = RequestMethod.POST)

public void uploadFile(@RequestParam("file") MultipartFile file, HttpServletRequest request, HttpServletResponse response) throws UnsupportedEncodingException {

request.setCharacterEncoding("gb2312");

if (file.isEmpty()) {

System.out.println("文件为空");

return;

}

InputStreamReader isr = null;

BufferedReader br = null;

try {

isr = new InputStreamReader(file.getInputStream(), "gb2312");

br = new BufferedReader(isr);

String line = null;

List> list = new ArrayList<>();

while ((line = br.readLine()) != null) {

list.add(Arrays.asList(line.split(",")));

}

// list即为所得，用于业务操作、数据持久保存等

}

catch (IOException e) {

e.printStackTrace();

}

finally {

try {

if (br != null) {

br.close();

}

if (isr != null) {

isr.close();

}

} catch (IOException e) {

e.printStackTrace();

}

}

}

/**

* 导出csv文件

* @param request

* @param response

* @throws IOException

*/

@RequestMapping(value = "/downloadFile", method = RequestMethod.POST)

public void downloadFile(HttpServletRequest request, HttpServletResponse response) throws IOException {

response.setContentType("application/x-download");

response.addHeader("Content-Disposition", "attachment;filename="+new String( "导出文件名".getBytes("utf-8"), "ISO8859-1" )+".csv");

OutputStream out = response.getOutputStream();

// 模拟生成字符串，一般是后台查询sql结果集拼接而成

String csvFile = ""客户姓名","客户类型","联系方式"n"张三","对私","13055874405t"n"XX集团","对公","0591-8857448t"";

// 向out中写入流

out.write((csvFile).toString().getBytes("gb2312"));

out.flush();

response.flushBuffer();

}

}

备注：生成csv文件若要为文本格式需在每个数据后面加t转义符；

出入参的编码根据实际情况转换(用GB2312编码或可避免中文缺失或乱码问题)；