实际参数列表和形式参数列表长度不同

import java.util.*;

class Person
{
private int age;
public Person(){}
//
public Person(int age)
{
this.age = age;
}
public int getAge()
{
return this.age;
}
}

public class TestFinalReference
{
public static void main(String[] args)
{
//
final int[] iArr = {5,6666,99,45,3};
System.out.println(Arrays.toString(iArr));
//
Arrays.sort(iArr);
System.out.println(Arrays.toString(iArr));
//
iArr[2] = -65;
System.out.println(Arrays.toString(iArr));
//
//iArr = null;
//
final Person p = new Person(6);
p.getAge(23);
System.out.println(p.getAge);
//p = null;
}
}

System.out.println(p.getAge()); //少括号

 /* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;


class Person
{
private int age;
public Person(){}
//
public Person(int age)
{
this.age = age;
}
public void setAge(int age)
{
    this.age = age;
}
public int getAge()
{
return this.age;
}
}

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
    public static void main (String[] args) throws java.lang.Exception
    {
        // your code goes here
        //
        final int[] iArr = {5,6666,99,45,3};
        System.out.println(Arrays.toString(iArr));
        //
        Arrays.sort(iArr);
        System.out.println(Arrays.toString(iArr));
        //
        iArr[2] = -65;
        System.out.println(Arrays.toString(iArr));
        //
        //iArr = null;
        //
        Person p = new Person(6);
        p.setAge(23);
        System.out.println(p.getAge());
        //p = null;
    }
}

在线测试通过
http://ideone.com/KecyeY

 p.getAge(23);
这个也不对，你是不是想写set方法
p.setAge(23);

在Person类里面加上
public void setAge(int age)
{
this.age = age;
}