Java:Apache-Commons CSV文件的读和写

摘要：

CSV（Comma-Separated Values）逗号分隔值（有时也称为字符分隔值），因为分隔字符也可以不是逗号），文件是以纯文本形式存储表格数据，包括数字和文本。Apache Commons CSV下载地址： http://commons.apache.org/proper/commons-csv/download_csv.cgi

Java Bean：

package com.what21.apache.commons.csv;

public class User {

    private String username;

    private String password;

    private String name;

    private int age;

    public User(String username,String password,String name, int age){
        this .username = username;
        this .password = password;
        this .name = name;
        this .age = age;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this .username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this .password = password;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this .name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge( int age) {
        this .age = age;
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        sb.append( "username : " ).append( this .getUsername());
        sb.append( ", password : " ).append( this .getPassword());
        sb.append( ", name : " ).append( this .getName());
        sb.append( ", age : " ).append( this .getAge());
        return sb.toString();
    }

}

输出CSV文件：

package com.what21.apache.commons.csv;

import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVPrinter;

/**
 * @author ashraf
 *
 */
public class CsvFileWriter {

    //CSV文件分隔符
    private static final String NEW_LINE_SEPARATOR = "\n" ;

    //CSV文件头
    private static final Object [] FILE_HEADER = { "用户名" , "密码" , "名称" , "年龄" };

    /**
     * 写CSV文件
     *
     * @param fileName
     */
    public static void writeCsvFile(String fileName) {
        FileWriter fileWriter = null ;
        CSVPrinter csvFilePrinter = null ;
        //创建 CSVFormat
        CSVFormat csvFileFormat = CSVFormat.DEFAULT.withRecordSeparator(NEW_LINE_SEPARATOR);
        try {
            //初始化FileWriter
            fileWriter = new FileWriter(fileName);
            //初始化 CSVPrinter
            csvFilePrinter = new CSVPrinter(fileWriter, csvFileFormat);
            //创建CSV文件头
            csvFilePrinter.printRecord(FILE_HEADER);

            // 用户对象放入List
            List userList = new ArrayList ();
            userList.add( new User( "zhangsan" , "123456" , "张三" , 25 ));
            userList.add( new User( "lisi" , "123" , "李四" , 23 ));
            userList.add( new User( "wangwu" , "456" , "王五" , 24 ));
            userList.add( new User( "zhaoliu" , "zhaoliu" , "赵六" , 20 ));

            // 遍历List写入CSV
            for (User user : userList) {
                List userDataRecord = new ArrayList();
                userDataRecord.add(user.getUsername());
                userDataRecord.add(user.getPassword());
                userDataRecord.add(user.getName());
                userDataRecord.add(String.valueOf(user.getAge()));
                csvFilePrinter.printRecord(userDataRecord);
            }
            System.out.println( "CSV文件创建成功~~~" );

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                fileWriter.flush();
                fileWriter.close();
                csvFilePrinter.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args){
        writeCsvFile( "c://users.csv" );
    }

}

读取CSV文件：

package com.what21.apache.commons.csv;

import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.CSVRecord;

/**
 * @author ashraf_sarhan
 *
 */
public class CsvFileReader {

    //CSV文件头
    private static final String [] FILE_HEADER = { "用户名" , "密码" , "名称" , "年龄" };

    /**
     * @param fileName
     */
    public static void readCsvFile(String fileName) {
        FileReader fileReader = null ;
        CSVParser csvFileParser = null ;
        //创建CSVFormat（header mapping）
        CSVFormat csvFileFormat = CSVFormat.DEFAULT.withHeader(FILE_HEADER);
        try {
            //初始化FileReader object
            fileReader = new FileReader(fileName);
            //初始化 CSVParser object
            csvFileParser = new CSVParser(fileReader, csvFileFormat);
            //CSV文件records
            List csvRecords = csvFileParser.getRecords();
            // CSV
            List userList = new ArrayList();
            //
            for ( int i = 1 ; i < csvRecords.size(); i++) {
                CSVRecord record = csvRecords.get(i);
                //创建用户对象填入数据
                User user = new User(record.get( "用户名" ), record.get( "密码" ),
                            record.get( "名称" ), Integer.parseInt(record.get( "年龄" )));
                userList.add(user);
            }
            // 遍历打印
            for (User user : userList) {
                System.out.println(user.toString());
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                fileReader.close();
                csvFileParser.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args){
        readCsvFile( "c://users.csv" );
    }

}

 PS:与javacsv相比，读取速度慢，主要在于组装对象占用了大量的事件。