Test.java

package test;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.concurrent.Callable;

import api.Unchecked;

public class Test {
  public static void main(String[] args) {
    String fileContent = Unchecked.with(new Callable<String>() {
      @Override
      public String call() throws Exception {
        return getFileContent("/home/itang/.bashrc");
      }
    });
    System.out.println(fileContent);

    try {
      Unchecked.with(new Callable<String>() {
        @Override
        public String call() throws Exception {
          return getFileContent("/home/itang/.bashrc_bad");
        }
      });
    } catch (RuntimeException e) {
      System.out.println(e.getMessage());
    }
  }

  private static String getFileContent(String path) throws IOException {
    BufferedReader reader = new BufferedReader(new FileReader(path));
    String line = null;
    StringBuilder sb = new StringBuilder();
    String lineSp = System.getProperty("line.separator");
    while ((line = reader.readLine()) != null) {
      sb.append(line).append(lineSp);
    }
    return sb.toString();
  }
}

Unchecked.java

package api;

import java.util.concurrent.Callable;

public class Unchecked {
  public static <T> T with(Callable<T> call) {
    try {
      return call.call();
    } catch (RuntimeException e) {
      throw e;
    } catch (Throwable e) {
      throw new RuntimeException(e);
    }
  }
}