JButton[] forButtons = new JButton[]{grayButton,ZhifangButton,lianTongYu};

------解决方案--------------------
把5 去掉。
如果你一定要初始化length为5的数组，
则在后面加两个null，null吧。

------解决方案--------------------
既然是JButton类型数组  那么数组元素也必须的是JButton类型

------解决方案--------------------
楼上的说的对
JButton[] forButtons = new JButton[]{grayButton,ZhifangButton,lianTongYu};  
或者
JButton[] forButtons = new JButton[5]{grayButton,ZhifangButton,lianTongYu,null,null};  



------解决方案--------------------
JButton[] forButtons = new JButton[]{grayButton,ZhifangButton,lianTongYu};  
楼上说的都没错，这个叫做静态初始化，系统会依据你给的数据数据的个数来自动帮你确定数组的大小。

------解决方案--------------------
JButton[] forButtons = new JButton[]{grayButton,ZhifangButton,lianTongYu,null,null};  
JButton[] forButtons = new JButton[5];
JButton[] forButtons = {grayButton,ZhifangButton,lianTongYu,null,null};
这些都是合法的初始化

------解决方案--------------------
探讨

JButton[] forButtons = new JButton[]{grayButton,ZhifangButton,lianTongYu,null,null}; 
JButton[] forButtons = new JButton[5]; 
JButton[] forButtons = {grayButton,ZhifangButton,lianTongYu,null,null}; 
这些都是合法的初始化