java中字符串转化为方法调用

public void say(String[] str,PrintWriter pw){
System.out.println("hello "+str[0]+"     "+str[3]);
pw.println("hello  "+str[0]);
pw.flush();
pw.close();
}

public void test() throws IllegalArgumentException, IllegalAccessException, InvocationTargetException, SecurityException, NoSuchMethodException, IOException{

PrintWriter pw=new PrintWriter(new FileWriter("E://test.txt"));
String aa="say";
String ipInfo[]={"1","2","3","4"};

Method sAge = this.getClass().getMethod(aa, new Class[] {String[].class,PrintWriter.class});
//获得参数Object
Object[] arguments = new Object[] {ipInfo,pw};
//执行方法
sAge.invoke(this , arguments);

}