JAVA 예외 던지기 Throw

직접 만드는 예외

예외를 직접 발생시킬 경우 키워드 throw를 활용한다.

public static void main(String[] args) throws Exception {
	throw new Exception("예외 강제 발생");
}

 

package kr.or.ksmart;

class MyExecption extends Exception {
	
	public MyExecption() {
		super();
	}
	
	public MyExecption (String msg) {
		super(msg + " < My 클래스의 필수값 누락 MyExecption ");
	}
}

class My {
	private String name;
	
	public My(String name) throws MyExecption {
		if(name == null || "".equals(name)) {
			throw new MyExecption(name + "인수값 null이나 공백");
		}
	}
	
	public void setMyAge(int age) throws MyExecption {
		if(age == 0) {
			throw new MyExecption("age 값이 0");
		}
	}
}

public class Exception03 {

	public static void main(String[] args) {
		My my  = null;
		try {
			//my = new My("");  <- 생성자 메서드에서 공백 혹은 null일때 예외 발생
			my = new My("홍길동");
			
		} catch (MyExecption e) {
			e.printStackTrace();
		}
		try {
			my.setMyAge(0); // 0값일 경우 강제 예외 발생
		} catch (MyExecption e) {
			e.printStackTrace();
		}
	}

}

 

package kr.or.ksmart;

class MemberException extends Exception {
	public MemberException (){
		super();
	}
	public MemberException (String msg) {
		super(msg + " <- MemberException.java 필수정보 누락 예외;");
	}
}

class Member {
	private String userName;
	
	public void setUserName (String userName) throws MemberException {
		if(userName == null || "".equals(userName)) {
			throw new MemberException (" <- userName의 값이 null이거나 공백; ");
		}
	}
}

public class ExceptionEx01 {

	public static void main(String[] args) {
    
      try {
      Member member = new Member();
      member.setUserName("");

      } catch (MemberException e) {
      e.printStackTrace();
      }
	}

}