Question

我尝试了两个版本，但都重复打印出程序的其他部分。

版本1（带换行符）

try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
    while(true) {
        String input = br.readLine();
        if(input != null) {
            SomeRequest req = new SomeRequest();
            req.text = input;
            client.sendTCP(req);
        } else {
            System.out.println("non stop..."); <-- this continously prints  
        }
    }
}

版本2（没有换行）

try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
    while(true) {
        String input = br.readLine();
        if(input != null) {
            SomeRequest req = new SomeRequest();
            req.text = input;
            client.sendTCP(req);
        } else {
            System.out.print("non stop..."); <-- this continously prints as well?   
        }
    }
}

版本3（抛出异常）

try(Scanner sc = new Scanner(System.in)) {
    String input = "";
    System.out.println("Enter to send");
    while(true) {
        if(!sc.hasNextLine()) {
            input = sc.nextLine();
            SomeRequest req = new SomeRequest();
            req.text = input;
            client.sendTCP(req);
        } else {
            System.out.println("not sending");
        }
    }
}

我试图让用户在控制台上打印一些内容，然后将其发送到服务器，如您所见。但是现在这个程序只是打印不停......

Answer 1

两个版本均无效。你没有在流结束时退出循环。它应该是：

try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
    String input;
    while ((input = br.readLine()) != null) {
        SomeRequest req = new SomeRequest();
        req.text = input;
        client.sendTCP(req);
        }
    }
    System.out.print("End of input");
}

BufferedReader没有阻塞输入

1 个答案: