java反射检测参数的某个字段不能为空

package test;

import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

/**
 * 
 * @author 0414
 *
 */
public class TestReflectChecker {

	public class Param {
		private String id;

		private String name;

		private String year;

		private String month;

		private String day;
		
		public Param() {}

		public String getDay() {
			return day;
		}

		public void setDay(String day) {
			this.day = day;
		}

		public String getId() {
			return id;
		}

		public void setId(String id) {
			this.id = id;
		}

		public String getMonth() {
			return month;
		}

		public void setMonth(String month) {
			this.month = month;
		}

		public String getName() {
			return name;
		}

		public void setName(String name) {
			this.name = name;
		}

		public String getYear() {
			return year;
		}

		public void setYear(String year) {
			this.year = year;
		}
	}

	/**
	 * CHECK_FIELD
	 */
	private enum CHECK_FIELD {
		id,

		name,

		year,

		month,

		day
	}

	private static Map<String, CHECK_FIELD[]> matchMap = new HashMap<String, CHECK_FIELD[]>();

	static {
		//id 1 : name is not null;
		matchMap.put("1",
				new CHECK_FIELD[] { CHECK_FIELD.id, CHECK_FIELD.name });

		//id 2 : year, month, day is not null;
		matchMap.put("2", new CHECK_FIELD[] { CHECK_FIELD.id, CHECK_FIELD.year,
				CHECK_FIELD.month, CHECK_FIELD.day });
	}

	private TestReflectChecker() {

	}

	/**
	 * パラメータをチェック
	 * 
	 * @param param
	 * @return
	 */
	public static boolean check(Param param) {
		if (param == null) {
			return false;
		}

		String id = param.getId();

		CHECK_FIELD[] checkFields = matchMap.get(id);

		if (checkFields == null) {
			return false;
		}

		for (CHECK_FIELD field : checkFields) {
			Method getFieldMethod = getGetMehtodByField(Param.class, field
					.toString());
			try {
				Object value = getFieldMethod.invoke(param, new Object[] {});
				if (value == null) {
					System.out.println(field + " is null, false will be return .");
					return false;
				}
			} catch (Exception e) {
				e.printStackTrace();
				return false;
			}
		}

		return true;
	}

	/**
	 * fieldからmethodを取得
	 * 
	 * @param clazz
	 * @param field
	 * @return
	 */
	private static Method getGetMehtodByField(Class clazz, String field) {
		Method method = null;

		String methodName = "get" + field.substring(0, 1).toUpperCase()
				+ field.substring(1);
		try {
			method = clazz.getMethod(methodName, new Class[] {});
		} catch (Exception e) {
			e.printStackTrace();
		}
		return method;
	}

	public static void main(String[] args) {
		Param param = new TestReflectChecker().new Param();
		param.setId("1");
		param.setName("name");
		System.out.println(TestReflectChecker.check(param));
		
		param.setId("2");
		param.setYear("2011");
		System.out.println(TestReflectChecker.check(param));
	}

}