com.cybermkd.route.holder.ExceptionHolder Maven / Gradle / Ivy

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package com.cybermkd.route.holder;

import com.cybermkd.common.Constant;
import com.cybermkd.common.http.HttpRequest;
import com.cybermkd.common.http.HttpResponse;
import com.cybermkd.common.http.result.HttpStatus;
import com.cybermkd.log.Logger;

import javax.servlet.ServletException;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import static com.cybermkd.common.util.Checker.checkNotNull;

/**
 * Created by Dreampie on 15/4/27.
 */
public abstract class ExceptionHolder {
    public final static ExceptionHolder HOLDER;
    private final static Logger logger = Logger.getLogger(ExceptionHolder.class);
    private static String defaultUrl;
    private static boolean forward;
    private static Map forwardMap = new HashMap();
    private static Map redirectMap = new HashMap();

    static {
        ExceptionHolder exceptionHolder = null;
        if (Constant.exceptionHolder == null) {
            exceptionHolder = new DefaultExceptionHolder();
        } else {
            try {
                Class holderClass = Class.forName(Constant.exceptionHolder);
                exceptionHolder = (ExceptionHolder) holderClass.newInstance();
            } catch (ClassNotFoundException e) {
                logger.error("Could not found ExceptionHolder Class.", e);
            } catch (InstantiationException e) {
                logger.error("Could not init ExceptionHolder Class.", e);
            } catch (IllegalAccessException e) {
                logger.error("Could not access ExceptionHolder Class.", e);
            }
        }
        HOLDER = exceptionHolder;
    }

    public static void setDefaultForward(String url) {
        setDefault(url, true);
    }

    public static void setDefaultRedirect(String url) {
        setDefault(url, false);
    }

    private static void setDefault(String url, boolean isForward) {
        if (defaultUrl != null) {
            throw new IllegalArgumentException("Default url only can set once.");
        }
        defaultUrl = checkNotNull(url, "Url could not be null.");
        forward = isForward;
    }

    public static void addFoward(HttpStatus status, String url) {
        forwardMap.put(status, checkNotNull(url, "Url could not be null."));
    }

    public static void addRedirect(HttpStatus status, String url) {
        redirectMap.put(status, checkNotNull(url, "Url could not be null."));
    }

    /**
     * 捕获异常 并就行跳转
     *
     * @param response  response
     * @param status    status
     * @param isHandled isHandled
     * @return url
     * @throws ServletException
     * @throws IOException
     */
    protected static void go(HttpResponse response, HttpStatus status, boolean[] isHandled) {
        String url = forwardMap.get(status);
        try {
            //forwar
            if (url != null) {
                response.forward(url);
            } else {
                url = redirectMap.get(status);
                //redirect
                if (url != null) {
                    response.sendRedirect(url);
                } else {
                    //默认跳转
                    if (defaultUrl != null) {
                        url = defaultUrl;
                        if (forward) {
                            response.forward(defaultUrl);
                        } else {
                            response.sendRedirect(defaultUrl);
                        }
                    } else {
                        isHandled[0] = false;
                        if (logger.isWarnEnabled()) {
                            logger.warn("ICEREST not handle this request.");
                        }
                    }
                }
            }
        } catch (Exception e) {
            if (logger.isErrorEnabled()) {
                logger.error("Response going error.", e);
            }
        }
    }

    /**
     * 处理异常
     *
     * @param request
     * @param response
     * @param exception
     * @param isHandled
     */
    public abstract void hold(HttpRequest request, HttpResponse response, Exception exception, boolean[] isHandled);
}