transform Raw UTF8 input from a file to a Java escaped string.

UTF8toJavaCode

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.charset.Charset;

/**
 * @author amedrano
 *
 */
public class UTF8toJavaCode {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		String utf;
		try {
			utf = readFile(args[0]);
		} catch (IOException e) {
			e.printStackTrace();
			utf="";
		}

		// convert the input string to a character array  
		char[] chars = utf.toCharArray();  
		  
		StringBuilder sb = new StringBuilder();  
		for (int i = 0; i < chars.length; i++)  
		{  
		    int unipoint = Character.codePointAt(chars, i);  
		    if ((unipoint < 32) || (unipoint > 127))  
		    {  
		        StringBuilder hexString = new StringBuilder();  
		        for (int k = 0; k < 4; k++) // 4 times to build a 4-digit hex  
		        {  
		            hexString.insert(0, Integer.toHexString(unipoint % 16));  
		            unipoint = unipoint / 16;  
		        }  
		        sb.append("\\u"+hexString);  
		    }  
		    else  
		    {  
		        sb.append(chars[i]);  
		    }  
		}  
		  
		// display the ASCII encoded string  
		System.out.println ("String s = " + sb.toString());  
	}

	private static String readFile(String path) throws IOException {
		  FileInputStream stream = new FileInputStream(new File(path));
		  try {
		    FileChannel fc = stream.getChannel();
		    MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
		    /* Instead of using default, pass in a decoder. */
		    return Charset.defaultCharset().decode(bb).toString();
		  }
		  finally {
		    stream.close();
		  }
		}
}