Java键盘录入的三种方式

分手后的思念是犯贱 2023-06-26 12:09 31阅读 0赞

## Java键盘录入三种方法 ##

**方法一：Scanner类中的方法**

优点一: 可以获取键盘输入的字符串  
优点二: 有现成的获取int,float等类型数据，非常强大，也非常方便

**方法二：System.in和System.out方法** (使用read)

缺点一: 该方法能获取从键盘输入的字符，但只能针对一个字符的获取  
缺点二: 获取的只是char类型的。如果想获得int,float等类型的输入,比较麻烦。

**方法三：InputStreamReader和BufferedReader方法** （使用readline）

优点: 可以获取键盘输入的字符串  
缺点: 如何要获取的是int,float等类型的仍然需要转换

**注意，方法二、方法三都借助于read()方法，其为阻塞时方法，既等待输入后才会继续运行。**

以下为程序实例。

/** * 键盘录入 * @author 段 * @date 2019.12.31 */
    import java.io.*;
    import java.util.*;
    public class KeyRu{ 
        public static void main(String[] args){ //main函数
            SystemCharTest();//调用System.in方法
            ReadStringTest();//调用readline方法，使用BuffererReader缓冲区与InputStreamReader流
            ScannerAllTest();//调用Scanner方法
        }
    public static void ScannerAllTest(){ 
        Scanner read=new Scanner(System.in);
        System.out.println("please enter name");
        String name =read.nextLine();//read String keyboard entry
        System.out.println("please enter age");
        int age=read.nextInt();//读取整数输入
        System.out.println("Please entry score");
        double score=read.nextDouble();//读取double输入
        System.out.println("The information you enter is as follows:");
        System.out.print(name+"\t"+age+"\t"+score);
    }
    public static void SystemCharTest(){ 
        try{     //该方法中有个IOExcepiton需要捕获 
            System.out.println("Please enter a char");
            char c =(char)System.in.read();
            System.out.println ("The char that you entry is \t"+ c);
        }
        catch(IOException ex){ 
            
            ex.printStackTrace();
        }
    }
    public static void ReadStringTest(){ 
        System.out.println("please enter string");
        /*InputStreamReader is = new InputStreamReader(System.in); //new构造InputStreamReader对象 BufferedReader br = new BufferedReader(is); //拿构造的方法传到BufferedReader中 */
    // BufferedReader br=new BufferedReader(new InputStreamReader(System.in));//简化
        try(BufferedReader br=new BufferedReader(new InputStreamReader(System.in));)//try块退出时，会自动调用res.close()方法，关闭资源。
        {  //该方法中有个IOExcepiton需要捕获 
          String name = br.readLine(); 
          System.out.println("ReadTest Output:" + name); 
        } 
        catch(IOException ex){  
          ex.printStackTrace(); 
        }
    }
    }

**注意：每个方法应单独演示。**

# 路阻且长之Java学习： #

**[API中的重要类（一）：][API]  
https://blog.csdn.net/Veer\_c/article/details/103803248  
[API中的重要类（二）：][API 1]  
https://blog.csdn.net/Veer\_c/article/details/103807515  
[API中的重要类（三）：][API 2]  
https://blog.csdn.net/Veer\_c/article/details/103808054**

**[Java中的IO流（一）：][Java_IO]  
https://blog.csdn.net/Veer\_c/article/details/103833045  
[Java中的IO流（二）：][Java_IO 1]  
https://blog.csdn.net/Veer\_c/article/details/103833423  
[Java中的IO流（三）：][Java_IO 2]  
https://blog.csdn.net/Veer\_c/article/details/103833811**

**[Java多线程（一）：][Java]  
https://blog.csdn.net/Veer\_c/article/details/103842078  
[Java多线程（二）：][Java 1]  
https://blog.csdn.net/Veer\_c/article/details/103842263  
[Java多线程（三）：][Java 2]  
https://blog.csdn.net/Veer\_c/article/details/103842317  
[Java多线程（四）：][Java 3]  
https://blog.csdn.net/Veer\_c/article/details/103842602**

**[网络编程上（UDP）：][UDP]  
https://blog.csdn.net/Veer\_c/article/details/103843591  
[网络编程下（TCP）：][TCP]  
https://blog.csdn.net/Veer\_c/article/details/103843825**

**[MySQL数据库（一）：][MySQL]  
https://blog.csdn.net/Veer\_c/article/details/103844059  
[MySQL数据库（二）：][MySQL 1]  
https://blog.csdn.net/Veer\_c/article/details/103844537  
[MySQL数据库（三）：][MySQL 2]  
https://blog.csdn.net/Veer\_c/article/details/103844739**

**[JDBC技术（一）：][JDBC]  
https://blog.csdn.net/Veer\_c/article/details/103845176  
[JDBC技术（二）：][JDBC 1]  
https://blog.csdn.net/Veer\_c/article/details/103879890  
[JDBC技术（三）：][JDBC 2]  
https://blog.csdn.net/Veer\_c/article/details/103880021  
[JDBC技术（四）：][JDBC 3]  
https://blog.csdn.net/Veer\_c/article/details/103882264**

**[HTML的基础框架（一）：][HTML]  
https://blog.csdn.net/Veer\_c/article/details/103882385  
[HTML的基础框架（二）：][HTML 1]  
https://blog.csdn.net/Veer\_c/article/details/103882684**

**[CSS入门（一）][CSS]  
https://blog.csdn.net/Veer\_c/article/details/103882856**  
**[CSS入门（二）：][CSS 1]  
https://blog.csdn.net/Veer\_c/article/details/103883102**

**[JavaScript实用案例与常见问题（一）：][JavaScript]  
https://blog.csdn.net/Veer\_c/article/details/103894959  
[JavaScript实用案例及常见问题（二）：][JavaScript 1]  
https://blog.csdn.net/Veer\_c/article/details/103895166**

[API]: https://blog.csdn.net/Veer_c/article/details/103803248
[API 1]: https://blog.csdn.net/Veer_c/article/details/103807515
[API 2]: https://blog.csdn.net/Veer_c/article/details/103808054
[Java_IO]: https://blog.csdn.net/Veer_c/article/details/103833045
[Java_IO 1]: https://blog.csdn.net/Veer_c/article/details/103833423
[Java_IO 2]: https://blog.csdn.net/Veer_c/article/details/103833811
[Java]: https://blog.csdn.net/Veer_c/article/details/103842078
[Java 1]: https://blog.csdn.net/Veer_c/article/details/103842263
[Java 2]: https://blog.csdn.net/Veer_c/article/details/103842317
[Java 3]: https://blog.csdn.net/Veer_c/article/details/103842602
[UDP]: https://blog.csdn.net/Veer_c/article/details/103843591
[TCP]: https://blog.csdn.net/Veer_c/article/details/103843825
[MySQL]: https://blog.csdn.net/Veer_c/article/details/103844059
[MySQL 1]: https://blog.csdn.net/Veer_c/article/details/103844537
[MySQL 2]: https://blog.csdn.net/Veer_c/article/details/103844739
[JDBC]: https://blog.csdn.net/Veer_c/article/details/103845176
[JDBC 1]: https://blog.csdn.net/Veer_c/article/details/103879890
[JDBC 2]: https://blog.csdn.net/Veer_c/article/details/103880021
[JDBC 3]: https://blog.csdn.net/Veer_c/article/details/103882264
[HTML]: https://blog.csdn.net/Veer_c/article/details/103882385
[HTML 1]: https://blog.csdn.net/Veer_c/article/details/103882684
[CSS]: https://blog.csdn.net/Veer_c/article/details/103882856
[CSS 1]: https://blog.csdn.net/Veer_c/article/details/103883102
[JavaScript]: https://blog.csdn.net/Veer_c/article/details/103894959
[JavaScript 1]: https://blog.csdn.net/Veer_c/article/details/103895166