Java-读写CSV文件

青旅半醒 2022-05-08 05:18 420阅读 0赞

使用Apache的commons-csv包读写CSV文件，非常方便。  
pom依赖

<dependency>
    	<groupId>org.apache.commons</groupId>
    	<artifactId>commons-csv</artifactId>
    	<version>1.6</version>
    </dependency>

代码

package com.example.demo;
    
    import org.apache.commons.csv.CSVFormat;
    import org.apache.commons.csv.CSVParser;
    import org.apache.commons.csv.CSVPrinter;
    import org.apache.commons.csv.CSVRecord;
    
    import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.IOException;
    import java.nio.file.Files;
    import java.nio.file.Paths;
    
    /**
     * @author Walker
     * @since 1.0 2018-10-09
     */
    public class CSVTest {
    
        public static void main(String[] args) throws IOException {
    //        write();
    //        read();
            read2();
        }
    
        public static void write() throws IOException {
            try (
                    BufferedWriter writer = Files.newBufferedWriter(Paths.get("C:\\test.csv"));
                    CSVPrinter csvPrinter = new CSVPrinter(writer, CSVFormat.DEFAULT.withHeader(
                            "id", "name", "age"
                    ))
            ) {
                csvPrinter.printRecord("1", "test1", "11");
                csvPrinter.printRecord("2", "test2", "21");
                csvPrinter.printRecord("3", "test3", "31");
                csvPrinter.printRecord("4", "test4", "41");
                csvPrinter.printRecord("5", "test5", "51");
                csvPrinter.flush();
            }
    
        }
    
        /**
         * 读取包括头部第一行
         *
         * @throws IOException
         */
        public static void read() throws IOException {
            try (
                    BufferedReader reader = Files.newBufferedReader(Paths.get("C:\\test.csv"));
                    CSVParser parser = new CSVParser(reader, CSVFormat.DEFAULT)
            ) {
                for (CSVRecord csvRecord : parser) {
                    String id = csvRecord.get(0);
                    String name = csvRecord.get(1);
                    String age = csvRecord.get(2);
                    System.out.println("id : " + id);
                    System.out.println("name : " + name);
                    System.out.println("age : " + age);
                    System.out.println("---------------\n\n");
                }
            }
        }
    
        /**
         * 设置头部
         * @throws IOException
         */
        public static void read2() throws IOException {
            try (
                    BufferedReader reader = Files.newBufferedReader(Paths.get("C:\\test.csv"));
                    CSVParser parser = new CSVParser(reader, CSVFormat.DEFAULT
                            .withHeader("id", "name", "age")
                            .withIgnoreHeaderCase()
                            .withTrim())
            ) {
                //key:头部名,value:顺序
                System.out.println(parser.getHeaderMap());
                for (CSVRecord csvRecord : parser) {
                    System.out.println(csvRecord.getRecordNumber());
                    String id = csvRecord.get("id");
                    String name = csvRecord.get("name");
                    String age = csvRecord.get("age");
                    System.out.println("id : " + id);
                    System.out.println("name : " + name);
                    System.out.println("age : " + age);
                    System.out.println("---------------\n\n");
                }
            }
        }
    
    }