Java文件输入为命令行参数 [英] Java file input as command line argument

问题描述

如何处理从文件输入的Java中的信息。例如：假设您有一个文件input.txt。这个文件的内容是：
abcdefghizzzzjklmnop
azzbcdefghijklmnop

How do you process information in Java that was input from a file. For Example: suppose you have a file input.txt. The contents of this file is: abcdefghizzzzjklmnop azzbcdefghijklmnop

我的希望是将信息放入字符串的参数数组，以下代码将输出abcdefghizzzzjklmnop

My hope would be that the information would be put into the argument array of strings such that the following code would output "abcdefghizzzzjklmnop"

class Test {
    public static void main(String[] args) {
        System.out.println(args[0]);
    }
}

我使用的命令会抛出一个数组绑定异常。此命令为：

The command I have been using throws an array out of bound exception. This command is:

input.txt

java Test < input.txt

不基于文件的参数可以正常工作。即。 java测试hello和java测试& input.txt hello。

Non-file based arguments work fine though. ie. java Test hello,a nd java Test < input.txt hello.

更多信息：
我试图把文件内容全部放在一行，看看\\\
\r字符是否可能弄乱了。这似乎没有帮助。

More information: I have tried putting the file contents all on one line to see if \n \r characters may be messing things up. That didn't seem to help.

此外，我不能使用bufferedreader类，因为这是一个学校的程序，它必须与我的教授的shell脚本一起工作。

Also, I can't use the bufferedreader class for this because this is for a program for school, and it has to work with my professors shell script. He went over this during class, but I didn't write it down (or I can't find it).

任何帮助？

推荐答案

您应该能够从 System.in 中读取输入数据。

You should be able to read the input data from System.in.

这里有一些简单肮脏的示例代码。 javac Test.java; java Test& Test.java ：

Here's some quick-and-dirty example code. javac Test.java; java Test < Test.java:

class Test
{
    public static void main (String[] args)
    {
        byte[] bytes = new byte[1024];
        try
        {
            while (System.in.available() > 0)
            {
                int read = System.in.read (bytes, 0, 1024);
                System.out.write (bytes, 0, read);
            }
        } catch (Exception e)
        {
            e.printStackTrace ();
        }
    }
}

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