Переводим InputStream в String

package example;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Properties;

public class StreamToString {

public static void main(String[] args) {
StreamToString sts = new StreamToString();

/*
* Get input stream of our data file. This file can be in the root of
* you application folder or inside a jar file if the program is packed
* as a jar.
*/
InputStream is = sts.getClass().getResourceAsStream("/data.txt");

/*
* Call the method to convert the stream to string
*/
System.out.println(sts.convertStreamToString(is));
}

public String convertStreamToString(InputStream is) {
/*
* To convert the InputStream to String we use the BufferedReader.readLine()
* method. We iterate until the BufferedReader return null which means
* there's no more data to read. Each line will appended to a StringBuilder
* and returned as String.
*/
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();

String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}

return sb.toString();
}
}