Console
# Console
有时候，我们需要输入密码，此时如果用 System.in 会让密码明文显示到控制台上；而 Console 类能隐式输入密码。
# Console.readPassword()
我们可以用 Console.readPassword() 方法：
import java.io.Console;
public class Main {
public static void main(String[] args) throws Exception {
Console cnsl = System.console();
if (cnsl != null) {
String alpha = cnsl.readLine("Name: ");
System.out.println("Name is: " + alpha);
char[] pwd = cnsl.readPassword("Password: ");
System.out.println("Password is: " + pwd);
}
}
}
package chapter11;
import java.io.Console;
public class IODemo13Console {
public static void main(String[] args) {
Console cnsl = System.console();
if (cnsl != null) {
String alpha = cnsl.readLine("Name: ");
System.out.println("Name is: " + alpha);
char[] pwd = cnsl.readPassword("Password: ");
System.out.println("Password is: " + pwd);
}else {
System.out.println("Please run in terminal, not in IDE ");
}
}
}
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运行结果：
D:\Projects\LearnJavaSE\src> javac ./chapter11/IODemo13Console.java
PS D:\Projects\LearnJavaSE\src> java chapter11.IODemo13Console
Name: PeterJXL
Name is: PeterJXL
Password:
Password is: PeterJXL
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第 3 行：输入 Name 的时候，输入什么，命令行里就回显什么；
第 5 行：输入 Password 的时候，并没有在命令行里回显我输入的字符；
注意，得在命令行里运行，不能在 IDE 里运行。在 IDE 里运行的话获取不了对象，导致 NPE，可以参考：
Beware though, this doesn't work (opens new window) with the Eclipse console. You'll have to run the program from a true console/shell/terminal/prompt to be able to test it.
java - Hide input on command line - Stack Overflow (opens new window)
# 参考
上次更新: 2024/10/1 15:49:31
