使用OpenCsv读写csv文件

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前言：

      openCSV是最简单易懂的CSV解析器之一，它使用标准Reader/Writer类并CSVReader在顶部提供实现。OpenCSV读取CSV的速度比使用Apache Commons CSV读取的速度要快，因为CSVWriter使用该CSVToBean.parse()方法时，将CSV实现为多线程的。

1.引入依赖jar

<dependency> <groupId>com.opencsv</groupId> <artifactId>opencsv</artifactId> <version>4.0</version> </dependency>

2.写csv文件

 private void writerFile() throws Exception { String outFileName = "/user/desktop/outFileName.csv"; Writer writer = Files.newBufferedWriter(Paths.get(outFileName)); CSVWriter csvWriter = new CSVWriter(writer, CSVWriter.DEFAULT_SEPARATOR, CSVWriter.NO_QUOTE_CHARACTER, CSVWriter.DEFAULT_ESCAPE_CHARACTER, CSVWriter.DEFAULT_LINE_END); String[] headerRecord = {"id", "name", "phone", "address"}; csvWriter.writeNext(headerRecord); List<User> querys = userMapper.selectAll(); if (querys != null) { for (User suer : querys) { csvWriter.writeNext(new String[]{user.getId().toString(),user.getUserName(),user.getPhone(),user.getAddress()}); System.out.println("count 写入行数：" + count); csvWriter.flush(); } csvWriter.close(); } }

3.读csv文件

 private void readCsvFile() throws Exception { String fileName = "/user/desktop/readFileName.csv"; Reader reader = Files.newBufferedReader(Paths.get(fileName)); CSVReader csvReader = new CSVReader(reader); String[] nextRecord; while ((nextRecord = csvReader.readNext()) != null) { String name = nextRecord[0]; String age = nextRecord[1]; String address = nextRecord[2]; System.out.println("name:" + name + "age:" + age + "address" + address); } }