Try catch

I need to write a try catch method wrapped around this logic, in the try though I am checking to see if z7 is true then return DUNS then a catch statement that will return "FALSE", but for some reason z7 s not looking for the boolean true it is looking to find a string true, how do I get it to recognize booleon? and write the try catch?

String soldTo = "";

soldTo = CommonFunctions.executeValueMapping(z1[0],z2[0],z3[0],z4[0],z5[0],z6[0],z7[0],z8[0], container);

for (int i =0;i < z8.length; i++) {

if (z7<i>.equals(true)){

result.addValue("DUNS");

}

else{

result.addValue("false");

}

}