how to redirect stdin and stdout to a text file in java

java

Solution

You don't have to do that in Java, you can do it from the shell that runs your Java application:

# cat input.txt | java -jar myapp.jar > output.txt

The Java code can then just read from System.in and write to System.out.

Problem

How to redirect stdin and stdout to take data as input from a text file and pass data as output to another textfile. My input and output files look like this. Input File.txt ``` 1 2 3 ``` The output should be the sum of the numbers in the input file. Output File.txt ``` 6 ```

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