Identify Duplicate Line And Print Them As Duplicate Found

I have a java file 'Arithmetic.java', in which i have 2 overridden method.Now i wanted to read this file and i need to print all the method signature lines,if i found same(overridden method)signature then i have to print "overridden method found". once i find the overridden method i have to suffix the method name as methodName_overridden1, methodName_overridden2 and so on...

package com.abcd.arithmetic;
public class AllArithmatic
{
public Integer add(int x,int y,int z)
{
return (x+y-z);
}
public Float substract(float x, float y)

[code]....

till now i am able to read the lines, able to read the method names as well. but while putting the entire method signatures into an string array and the suffixing part , i am not able to proceed. The condition i have put to find out oerridden method is nnot working.i am stucked in comparing the duplicate method

//Finds Method Name, Method Return Type
if(indexOfMethod >-1 && indexOfOpenBrace >-1){
int uniqueWordsInFile=0;
//Method signature Start
//System.out.println("method line="+line.trim());
List<String> methodList = new ArrayList<String>();
methodList.add(line.trim());

[code]....