JSON: Property 'xxx' has no getter method in class 'class xxx'

在做数据转换为JSON格式时：

import net.sf.json.JSONArray;

class T{
	private String name;
	private int age;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}	
}
public class JSONTest2 {
	public static void main(String[] args) {
		T t = new T();
		t.setName("zhangsan");
		t.setAge(20);
		
		JSONArray json = JSONArray.fromObject(t);
		System.out.println(json);
		
		//System.out.println(t.getName());
		//System.out.println(t.getAge());
	}
}

出现了如下错误：

thread "main" net.sf.json.JSONException: java.lang.NoSuchMethodException: Property 'age' has no getter method in class 'class T'

原因是 声明bean为public  class 必须是public