使用Java Scanner类解析CSV文件

本文将为你介绍如果使用Java的Scanner类来读取或者解析CSV文件。

我的CSV文件（user.csv）内容如下

Rockey,22,India
Bill,23,US
Sonia,23,Germany

接下来我们首先从创建映射上述属性的实体User.java

public class User {

    private String name;
    private int age;
    private String address;
    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;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    @Override
    public String toString() {
	return "User [name=" + name + ", age=" + age + ", address=" + address + "]";
    }
    
    
}

如果你查看Scanner的API，你会发现该类支持文件和输入流作为输入方式，本例中我们采用文件的方式。

CSVParsingExample.java

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class CSVParsingExample {

    public static void main(String[] args) throws IOException {
	Scanner scanner = new Scanner(new File("user.csv"));
	Scanner valueScanner = null;
	int index = 0;
	List<User> userList = new ArrayList<>();

	while (scanner.hasNextLine()) {
	    valueScanner = new Scanner(scanner.nextLine());
	    valueScanner.useDelimiter(",");
	    User user = new User();

	    while (valueScanner.hasNext()) {
		String data = valueScanner.next();
		if (index == 0){
		    user.setName(data);
		}
		else if (index == 1){
		    user.setAge(Integer.parseInt(data));
		}
		else if (index == 2){
		    user.setAddress(data);
		}
		index++;
	    }
	    index = 0;
	    userList.add(user);
	}

	scanner.close();

	System.out.println(userList);

    }

}

从上面代码可以看出，Scanner的nextLine(), hasNext() 方法可以很方便的帮助我们迭代数据，转化成我们想要的格式。

输出

[User [name=Rockey, age=22, address=India], User [name=Bill, age=23, address=US], User [name=Sonia, age=23, address=Germany]]

原文地址：https://www.javatips.net/blog/read-csv-file-using-java-scanner-class