package zzzTest; import java.util.List; public class StaticFunctionTest { static class test { int id; String name; public test(int id, String name) { this.id = id; this.name = name; } @Override public String toString() { return "test{" + "id=" + id + ", name='" + name + '\'' + '}'; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } } public static void main(String[] args) { String xx = null; test t = new test(1, xx); System.out.println(t.toString()); setTestId(t); System.out.println(t.toString()); } public static void setTestId(test t) { t.setId(2); } }