How to read the System properties into file dynamically

[meruva surendra]

Hi,

I am trying to to read the System properties into file dynamically. But i can't get the expected result. Please help me.

Advance Thanks,

ReadFromFile.java

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Properties;
public class ReadFromFile {
	 public static void main(String[] args) throws FileNotFoundException, IOException
	    {
	        System.setProperty("tablename", "mytable");
	        
	        //Properties properties = new Properties();
		    InputStream in = new FileInputStream(new File("log.file"));
	        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
	        StringBuilder out = new StringBuilder();
	        String line;
	        while ((line = reader.readLine()) != null) {
	            out.append(line);
	        }
	        System.out.println(out.toString()); 
	        //Prints the string content read from input stream
	        reader.close();
	    }
}

log.file

${System.tablename}

Expected Result
mytable

Getting Result
${System.tablename}

[Partheban Udayakumar]

meruva surendra,

As you said, your log file contains a String "${System.tablename}". So when you print out it will give you a String "${System.tablename}".

Note: ${System.tablename} is different from "${System.tablename}"

[meruva surendra]

Thanks for prompt reply. String is not a issue but just i want to know the way(${System.tablename}) getting value into file is right or not???

[Partheban Udayakumar]

meruva surendra wrote:but just i want to know the way(${System.tablename}) getting value into file is right or not???

When running your program, it may or may not take the value (depends on how you have configured) but if you read the file and print it out it will display the string written inside the file.