/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.*;
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String s = "Some string preceding this {\"Key1\": \"Val1\", \"Key2\": {\"embedKey1\": \"embedVal1\", \"embedKey2\": \"embedVal2\"}, \"Key3\" : \"Val3\", \"Key3\": \"Val4\"}, some value proceeding it";
		Pattern p = Pattern.compile("(?s)\\{(.*)}");
    	Matcher m = p.matcher(s);
    	while(m.find()){
       		System.out.println(m.group(1));
    	}
	}
}

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