blocks|key|1088671|text|这是eclipse的bug+#122429。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1088672|entityMap|0|LINK|mutability|MUTABLE|url|https://bugs.eclipse.org/bugs/show_bug.cgi?id=122429^0|A|B|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

This is a <a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=122429" rel="noreferrer">bug #122429</a> of eclipse

blocks|key|874013|text|下面的代码片段应该可以解决这个问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|874014|private+String+readLine(String+format,+Object...+args)+throws+IOException+{
++++if+(System.console()+!=+null)+{
++++++++return+System.console().readLine(format,+args);
++++}
++++System.out.print(String.format(format,+args));
++++BufferedReader+reader+=+new+BufferedReader(new+InputStreamReader(
++++++++++++System.in));
++++return+reader.readLine();
}

private+char[]+readPassword(String+format,+Object...+args)
++++++++throws+IOException+{
++++if+(System.console()+!=+null)
++++++++return+System.console().readPassword(format,+args);
++++return+this.readLine(format,+args).toCharArray();
}|code-block|syntax|javascript|874015|在Eclipse中测试时，您的密码输入将以清晰的形式显示。至少，您将能够进行测试。只是不要在测试时输入你的真实密码。保留它以供生产使用;)。|874016|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

This code snippet should do the trick:

<pre><code>private String readLine(String format, Object... args) throws IOException {
 if (System.console() != null) {
 return System.console().readLine(format, args);
 }
 System.out.print(String.format(format, args));
 BufferedReader reader = new BufferedReader(new InputStreamReader(
 System.in));
 return reader.readLine();
}

private char[] readPassword(String format, Object... args)
 throws IOException {
 if (System.console() != null)
 return System.console().readPassword(format, args);
 return this.readLine(format, args).toCharArray();
}
</code></pre>

While testing in Eclipse, your password input will be shown in clear. At least, you will be able to test. Just don't type in your real password while testing. Keep that for production use ;).

blocks|key|1088607|text|如果没有控制台，则System.console()返回null。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1088608|您可以通过adding+a+layer+of+indirection+to+your+code或通过在外部控制台和attaching+a+remote+debugger中运行代码来解决此问题。|1088609|entityMap|0|LINK|mutability|MUTABLE|url|http://illegalargumentexception.blogspot.com/2010/09/java-systemconsole-ides-and-testing.html|1|https://stackoverflow.com/questions/104254/java-io-console-support-in-eclipse-ide^0|9|G|0|5|16|0|1L|R|1|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|U|8|@]|D|@$9|V|A|W|1|X]|$9|Y|A|Z|1|10]]|E|$]]|$1|H|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|O]]|P|$5|K|L|M|E|$N|Q]]]]

<code>System.console()</code> returns null if there is no console.

You can work round this either by <a href="http://illegalargumentexception.blogspot.com/2010/09/java-systemconsole-ides-and-testing.html" rel="noreferrer">adding a layer of indirection to your code</a> or by running the code in an external console and <a href="https://stackoverflow.com/questions/104254/java-io-console-support-in-eclipse-ide">attaching a remote debugger</a>.

blocks|key|874109|text|在尝试编写简单的命令行应用程序时，我也遇到了这个问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|874110|从System.in创建自己的BufferedReader对象的另一种方法是使用java.util.Scanner，如下所示：|874111|import+java.util.Scanner;

Scanner+in;
in+=+new+Scanner(System.in);

String+s+=+in.nextLine();|code-block|syntax|javascript|874112|当然，这不会是控制台的临时替代品，但会让您访问各种不同的输入功能。|874113|这是more+documentation+on+Scanner+from+Oracle。|offset|length|874114|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/8/docs/api/java/util/Scanner.html^0|0|0|0|0|2|15|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|10|8|@]|9|@$M|11|N|12|1|13]]|A|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

I also ran into this problem when trying to write a simple command line application. 

Another alternative to creating your own BufferedReader object from System.in is to use java.util.Scanner like this:

<pre><code>import java.util.Scanner;

Scanner in;
in = new Scanner(System.in);

String s = in.nextLine();
</code></pre>

Of course this will not be a drop-in replacement to Console, but will give you access to a variety of different input functions.

Here's <a href="http://docs.oracle.com/javase/8/docs/api/java/util/Scanner.html">more documentation on Scanner from Oracle</a>.

blocks|key|874180|text|我参考并使用了上面显示的formixian的答案。重点是使用(黑色)+cmd控制台来运行您的Java程序，如"ojonugwa+ochalifu“所建议的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|874181|​|874182|📷|atomic|offset|length|874183|874184|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/fe791e96f354d8740c22d44a6f3de417.png|imageAlt^0|0|0|0|1|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@$G|V|H|W|1|X]]|A|$]]|$1|I|3|C|5|6|7|Y|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|Q|R|-4]]]]

I refered&amp;used formixian's answer shown above. The point is use (black) cmd console to run your Java program as "ojonugwa ochalifu" suggested.

<a href="https://i.stack.imgur.com/C3Rle.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/C3Rle.png" alt="**"></a>

blocks|key|1088579|text|这就对了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1088580|您必须在Eclipse外部运行该应用程序。查看Eclipse中的启动器配置面板，看看是否能找到在单独的JVM中运行命令的选项。|1088581|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

That is right.

You will have to run the application outside of Eclipse. Look at the launcher configuration panels within Eclipse and see if you can spot the option that says to run the command in a separate JVM.

blocks|key|874230|text|如果您的IDE使用javaw而不是java，那么这个问题肯定会发生，因为javaw本质上是没有控制台窗口的java。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|874231|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

If your IDE uses javaw instead of java, then this issue is bound to happen as javaw is essentially java without console window.

blocks|key|1088924|text|尝试编译您的类并在终端中运行它。它起作用了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1088925|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Try to compile your class and run it in terminal. It works.

I was using <code>readLine</code> of <code>BufferedReader</code> to get input/new password from user, but wanted to mask the password so I am trying to use <code>java.io.Console</code> class. Problem is that <code>System.console()</code> returns <code>null</code> when an application is debugged in Eclipse. I am new to Java and Eclipse not sure is this the best way to achieve? I am right clicking on the source file and selecting "Debug As" > "Java Application". Is there any workaround?

System.console() returns null

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我使用BufferedReader的readLine从用户那里获取输入/新密码，但是想要屏蔽密码，所以我尝试使用java.io.Console类。问题是，在Eclipse中调试应用程序时，System.console()返回null。我是Java和Eclipse的新手，不确定这是实现的最佳方式吗？我右键单击源文件并选择"Debug As“> "Java Application”。有什么变通方法吗？

问System.console()返回null
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