Here you can find the source of getPrimitiveType(Class> clazz)
private static Class<?> getPrimitiveType(Class<?> clazz)
//package com.java2s; //License from project: Open Source License import java.util.HashMap; import java.util.Map; public class Main { private static final Map<Class<?>, Class<?>> CORRESPONDING_TYPES = new HashMap<>(); private static Class<?> getPrimitiveType(Class<?> clazz) { return CORRESPONDING_TYPES.containsKey(clazz) ? CORRESPONDING_TYPES.get(clazz) : clazz; }//from w w w. ja v a 2 s . c om }