[Java] 응답 데이터를 처리하는 로직을 HttpResponse 클래스로 분리 및 리팩토링

 

응답 데이터를 처리하는 로직을 HttpResponse 클래스로 분리

• 아래 코드를 보면 응답 데이터 처리를 위한 많은 중복이 있다. 중복을 제거하자.

private void response302LoginSuccessHeader(DataOutputStream dos) {
    try {
        dos.writeBytes("HTTP/1.1 302 Found \r\n");
        dos.writeBytes("Content-Type: text/html;charset=utf-8 \r\n");
        dos.writeBytes("Set-Cookie: logined=true \r\n");
        dos.writeBytes("Location: /index.html \r\n" );
        dos.writeBytes("\r\n");
    } catch (IOException e) {
        log.error(e.getMessage());
    }
}
private void response200HeaderWithCss(DataOutputStream dos, int lengthOfBodyContent) {
    try {
        dos.writeBytes("HTTP/1.1 200 OK \r\n");
        dos.writeBytes("Content-Type: text/css,*/*;q=0.1\r\n");
        dos.writeBytes("Content-Length: " + lengthOfBodyContent + "\r\n");
        dos.writeBytes("\r\n");
    } catch (IOException e) {
        log.error(e.getMessage());
    }
}

private void response200HeaderWithScript(DataOutputStream dos, int lengthOfBodyContent) {
    try {
        dos.writeBytes("HTTP/1.1 200 OK \r\n");
        dos.writeBytes("Content-Type: application/javascript\r\n");
        dos.writeBytes("Content-Length: " + lengthOfBodyContent + "\r\n");
        dos.writeBytes("\r\n");
    } catch (IOException e) {
        log.error(e.getMessage());
    }
}

private void response200Header(DataOutputStream dos, int lengthOfBodyContent) {
    try {
        dos.writeBytes("HTTP/1.1 200 OK \r\n");
        dos.writeBytes("Content-Type: text/html;charset=utf-8\r\n");
        dos.writeBytes("Content-Length: " + lengthOfBodyContent + "\r\n");
        dos.writeBytes("\r\n");
    } catch (IOException e) {
        log.error(e.getMessage());
    }
}

 

 

제거하려면?

• 응답 헤더 정보를 Map<String, String>으로 관리한다.

private Map<String, String> header = new HashMap<>();

 

• 응답을 보낼때 HTML, CSS, JS 파일을 직접 읽어 응답으로 보내는 메서드는 forward(), 요청한 URL이 아닌 전달받은 URL로 리다이렉트하는 메서드는 sendRedirect()로 구현한다.

public class HttpResponse {
	private static final Logger log = LoggerFactory.getLogger(HttpResponse.class);
	private Map<String, String> headers = new HashMap<>();
	DataOutputStream dos = null; 
	
	public HttpResponse(OutputStream out) {
		dos = new DataOutputStream(out);
	}
	public void addHeader(String key, String value) {
		headers.put(key, value);
	}
	
	public void forward(String url) {
		try {
			byte[] body = Files.readAllBytes(Paths.get("./webapp" + url));
			if( url.endsWith(".css") ) {
				headers.put("Content-Type", "text/css,*/*;q=0.1");
			} else if ( url.endsWith(".js") ) {
				headers.put("Content-Type", "application/javascript");
			} else {
				headers.put("Content-Type", "text/html;charset=utf-8");
			}
			headers.put("Content-Length", body.length + "");
			response200Header(dos);
			responseBody(dos, body);
			
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	public void sendRedirect( String redirectUrl ) {
        try {
        	dos.writeBytes("HTTP/1.1 302 Found \r\n");
        	processHeader();
            dos.writeBytes("Location: " + redirectUrl + " \r\n" );
            dos.writeBytes("\r\n");
        } catch (IOException e) {
            log.error(e.getMessage());
        }
	}
	
	private void processHeader() {
        Set<String> keySet = headers.keySet();
        for (String key : keySet) {
        	try {
				dos.writeBytes(key + ": " + headers.get(key) + " \r\n");
			} catch (IOException e) {
				e.printStackTrace();
			}
        }
	}
	
    private void response200Header(DataOutputStream dos) {
        try {
            dos.writeBytes("HTTP/1.1 200 OK \r\n");
            processHeader();
            dos.writeBytes("\r\n");
        } catch (IOException e) {
            log.error(e.getMessage());
        }
    }
    private void responseBody(DataOutputStream dos, byte[] body) {
        try {
            dos.write(body, 0, body.length);
            dos.flush();
        } catch (IOException e) {
            log.error(e.getMessage());
        }
    }
    
    public void forwardBody(String body) {
    	byte[] contents = body.getBytes();
    	headers.put("Content-Type", "text/html;charset=utf-8");
    	headers.put("Content-Length", contents.length +"");
    	response200Header(dos);
    	responseBody(dos, contents);
    }
}