double x = 0.20752992072049992;
String cad=String.valueOf(x);
cad = cad.substring(0,5); // y tendras "0.207"
x = Double.parseDouble(cad); // y tendras 0.207
double num=1234.567;
num=Math.rint(num*10)/10;
double num=1234.567;
num=Math.rint(num*100)/100;
double num=1234.567345;
num=Math.rint(num*1000)/1000;
private static String quitarDecimales(String num, int n_decimales) {
int indice = num.indexOf(".");
return indice + n_decimales < num.length() ? num.substring(0, indice + n_decimales+1)
:num.substring(0, num.length());
}
public static void main(String arg[]){
double num=0.20752992072049992;
String formatoNum=quitarDecimales(num+"", 3);
System.out.println(""+formatoNum);
}