实现一个类Single，包含:一个成员变量x，构造方法，重写toString，测试类

public class Single {
private int x;

public Single(int x) {
this.x = x;
}

public int getX() {
return x;
}

public void setX(int x) {
this.x = x;
}

@Override
public String toString() {
return "Single [x=" + x + "]";
}
}

//测试类
public class SingleTest {
public static void main(String[] args) {
Single s = new Single(10);
System.out.println(s);
}
}