状态码设计

场景

• 多层次状态码
• 可归类状态码

代码(spring-web)

package org.springframework.http;

public enum HttpStatus {
	 CONTINUE(100, "Continue"),
	 
	 OK(200, "OK"),
	 
	 MOVED_TEMPORARILY(302, "Moved Temporarily"),
	 
	 BAD_REQUEST(400, "Bad Request"),
	 NOT_FOUND(404, "Not Found"),
	 
	INTERNAL_SERVER_ERROR(500, "Internal Server Error"),
    BAD_GATEWAY(502, "Bad Gateway");

    private final int value;
    private final String reasonPhrase;

    private HttpStatus(int value, String reasonPhrase) {
        this.value = value;
        this.reasonPhrase = reasonPhrase;
    }
    
    public static HttpStatus valueOf(int statusCode) {
        HttpStatus[] var1 = values();
        int var2 = var1.length;

        for(int var3 = 0; var3 < var2; ++var3) {
            HttpStatus status = var1[var3];
            if (status.value == statusCode) {
                return status;
            }
        }
        throw new IllegalArgumentException("No matching constant for [" + statusCode + "]");
    }
    
    public boolean is1xxInformational() {
        return HttpStatus.Series.INFORMATIONAL.equals(this.series());
    }

    public boolean is2xxSuccessful() {
        return HttpStatus.Series.SUCCESSFUL.equals(this.series());
    }

    public boolean is3xxRedirection() {
        return HttpStatus.Series.REDIRECTION.equals(this.series());
    }

    public boolean is4xxClientError() {
        return HttpStatus.Series.CLIENT_ERROR.equals(this.series());
    }

    public boolean is5xxServerError() {
        return HttpStatus.Series.SERVER_ERROR.equals(this.series());
    }

    public HttpStatus.Series series() {
        return HttpStatus.Series.valueOf(this);
    }

	public static enum Series {
       INFORMATIONAL(1),
       SUCCESSFUL(2),
       REDIRECTION(3),
       CLIENT_ERROR(4),
       SERVER_ERROR(5);
        
	   private final int value;
			
       public static HttpStatus.Series valueOf(int status) {
            int seriesCode = status / 100;
            HttpStatus.Series[] var2 = values();
            int var3 = var2.length;

            for(int var4 = 0; var4 < var3; ++var4) {
                HttpStatus.Series series = var2[var4];
                if (series.value == seriesCode) {
                    return series;
                }
            }
            throw new IllegalArgumentException("No matching constant for [" + status + "]");
        }

        public static HttpStatus.Series valueOf(HttpStatus status) {
            return valueOf(status.value);
        }
	}

}