java 如何让 BufferedReader.readLine() 不挂起？
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How can you make BufferedReader.readLine() not hang?
提问by Cin316
Is there a way to make BufferedReader.readLine()not hang?
有没有办法让BufferedReader.readLine()不挂？
I'm creating a server that:
我正在创建一个服务器：
- Checks if the client has delivered any input.
- If not, it executes other code and eventually loops back to checking the client for input.
- 检查客户端是否提供了任何输入。
- 如果没有，它会执行其他代码并最终循环回到检查客户端的输入。
How can I check if the client has delivered any input without running readLine()? If I run readLine(), the thread will hang until input is delivered?
如何在不运行的情况下检查客户端是否提供了任何输入readLine()？如果我运行readLine()，线程将挂起直到输入被传送？
回答by Cin316
You can use BufferedReader.ready(), like this:
你可以使用BufferedReader.ready()，像这样：
BufferedReader b = new BufferedReader(); //Initialize your BufferedReader in the way you have been doing before, not like this.
if(b.ready()){
String input = b.readLine();
}
ready()will return trueif the source of the input has not put anything into the stream that has not been read.
ready()true如果输入源没有将任何内容放入尚未读取的流中，则将返回。
Edit: Just a note, ready will return truewhenever even only one character is present. You can use read()to check if there is a line feed or carriage return, and those would indicate an end of line.
编辑：只是一个注释，true即使只有一个字符存在，ready 也会返回。您可以read()用来检查是否有换行符或回车符，这些表示行尾。
For more info: http://docs.oracle.com/javase/7/docs/api/java/io/BufferedReader.html#ready()
更多信息：http: //docs.oracle.com/javase/7/docs/api/java/io/BufferedReader.html#ready()
