为什么Java对象比较都无法通过'=='和.equals（）方法进行？

我正在使用==和equals（）方法比较相同的对象，但是它们都失败了。我尝试了以下四种组合。请有人指导我犯错了。

public class Question {

int rollNo;
String name;

Question(int rollNo, String name) {
    this.rollNo = new Integer(rollNo);
    this.name = new String(name);
}

public int getRollNo() {
    return new Integer(rollNo);
}

public void setRollNo(int rollNo) {
    if(rollNo>0) this.rollNo = rollNo;
}

public String getName() {
    return new String(name);
}

public void setName(String name) {
    if(name!=null) this.name = name;
}

public static void main(String[] args) {
    Question obj1 = new Question(123, "Student1");
    Question obj2 = new Question(123, "Student1");
    Question obj3 = new Question(456, "Student2");

            // All if conditions are evaluating to false
    if(obj1 == obj2) System.out.println("Equal objects 1 and 2 using ==");
    if(obj1.equals(obj2)) System.out.println("Equal objects 1 and 2 using equals()");
    if(obj1 == new Question(123, "Student1")) System.out.println("Equal objects 1 and 2 using == and new");
    if((new Question(123, "Student1")).equals(obj2)) System.out.println("Equal objects 1 and 2 using equals() and new");        
}

}

我也欢迎就我的代码质量提出建议，因为我刚刚开始编码。