escape characters that are outside of the specified range in the form &#digits;

EscapeSpecialChars.java

public class EscapeSpecialChars {
	public static final char HEXA = 'H';
	public static final char DECIMAL = 'D';
	
	private int minRange;
	private int maxRange;
	private String prefixEscape;
	private String suffixEscape;
	private String exclusionCharList;
	private char formatMethod;
	
	//CONSTRUCTORS
	public EscapeSpecialChars(int minRange, int maxRange, String prefixEscape, String suffixEscape, String exclusionCharList, char formatMethod){
		this.minRange = minRange;
		this.maxRange = maxRange;
		this.prefixEscape = prefixEscape;
		this.suffixEscape = suffixEscape;
		this.exclusionCharList = exclusionCharList;
		this.formatMethod = formatMethod;
	}
	
	public EscapeSpecialChars(){
		this.minRange = 32;
		this.maxRange = 255;
		this.prefixEscape = "&#";
		this.suffixEscape = ";";
		this.exclusionCharList = "\n\t\r";
		this.formatMethod = EscapeHTML.DECIMAL;
	}
	
	//GETTERS
	public String getExclusionCharList() {
		return exclusionCharList;
	}

	public char getFormatMethod() {
		return formatMethod;
	}

	public int getMaxRange() {
		return maxRange;
	}

	public int getMinRange() {
		return minRange;
	}

	public String getPrefixEscape() {
		return prefixEscape;
	}

	public String getSuffixEscape() {
		return suffixEscape;
	}

	//SETTERS
	public void setExclusionCharList(String exclusionCharList) {
		this.exclusionCharList = exclusionCharList;
	}

	public void setFormatMethod(char formatMethod) {
		this.formatMethod = formatMethod;
	}

	public void setMaxRange(int maxRange) {
		this.maxRange = maxRange;
	}

	public void setMinRange(int minRange) {
		this.minRange = minRange;
	}

	public void setPrefixEscape(String prefixEscape) {
		this.prefixEscape = prefixEscape;
	}

	public void setSuffixEscape(String suffixEscape) {
		this.suffixEscape = suffixEscape;
	}

	//PUBLIC METHODS
	public String format(String str){
		String formattedText = "";
		
		if(formatMethod == EscapeHTML.HEXA){
			formattedText = formatHexa(str);
		} else if(formatMethod == EscapeHTML.DECIMAL){
			formattedText = formatDecimal(str);
		}else{
			System.err.println("Invalid format method");
		}
		
		return formattedText;
	}
	
	//PRIVATE METHODS
	private String formatHexa(String str){
		String formattedText = "";
		
		for (int i = 0; i < str.length(); i++) {
			int codePoint = (new Character(str.charAt(i)).hashCode());
			
			if(isInRange(codePoint) || isExcluded(codePoint)){
				formattedText += str.charAt(i);
			}else{
				String hexValue = "";
				hexValue = Integer.toHexString(codePoint);
				
				while(hexValue.length() < 4){
					hexValue = "0" + hexValue;
				}
				
				formattedText += prefixEscape + hexValue + suffixEscape;
			}				
		}
		
		return formattedText;
	}
	
	private String formatDecimal(String str){
		String formattedText = "";
		
		for (int i = 0; i < str.length(); i++) {
			int codePoint = (new Character(str.charAt(i)).hashCode());
				
			if(isInRange(codePoint) || isExcluded(codePoint)){
				formattedText += str.charAt(i);
			}else{
				formattedText += prefixEscape + codePoint + suffixEscape;
			}				
		}
		
		return formattedText;
	}
	
	private boolean isInRange(int ch){
		return ch >= minRange && ch <= maxRange;
	}
	
	private boolean isExcluded(int ch){
		return exclusionCharList.indexOf(ch) != -1);
	}
	
}