ErrorMessageEncoder.java

/* ==================================================================   
 * Created [2009-4-27 下午11:32:55] by Jon.King 
 * ==================================================================  
 * TSS 
 * ================================================================== 
 * mailTo:jinpujun@hotmail.com
 * Copyright (c) Jon.King, 2009-2012 
 * ================================================================== 
 */

package com.jinhe.tss.core.web.dispaly;

import org.apache.log4j.Logger;

import com.jinhe.tss.core.exception.IBusinessException;
import com.jinhe.tss.core.exception.UserIdentificationException;
import com.jinhe.tss.core.util.BeanUtil;

/**
 * <p>
 * ErrorMessageEncoder.java
 * 负责处理错误异常信息的消息编码器。
 * </p>
 *
 */
public class ErrorMessageEncoder implements IMessageEncoder {
    
    protected static final Logger log = Logger.getLogger(ErrorMessageEncoder.class);

    protected String message = null;

    private String description = null;

    private int relogin = 0; // 是否需重新登录系统

    /**
     * 错误信息类型：
     * <li>1－普通业务逻辑错误信息，没有异常发生的
     * <li>2－有异常发生，同时被系统捕获后添加友好错误消息的
     * <li>3－其他系统没有预见的异常信息
     */
    private int type = 1;

    public ErrorMessageEncoder(String errorMessage) {
        this(errorMessage, 0);
    }

    public ErrorMessageEncoder(String errorMessage, int relogin) {
        this(errorMessage, null, relogin);
    }

    public ErrorMessageEncoder(String errorMessage, String description) {
        this(errorMessage, description, 0);
    }

    public ErrorMessageEncoder(String errorMessage, String description, int relogin) {
        this.message = errorMessage;
        this.description = description;
        this.relogin = relogin;
    }

    public ErrorMessageEncoder(Throwable exception) {
        this(getExceptionMessage(exception), exception);
    }

    public ErrorMessageEncoder(String errorMessage, Throwable exception) {
        this.message = errorMessage;
        this.description = getDescription(exception);
        if (BeanUtil.isImplInterface(exception.getClass(), IBusinessException.class)) {
            this.type = 2;
            this.relogin = ((IBusinessException) exception).getRelogin();
        } else {
            this.type = 3;
        }
    }

    private static String getExceptionMessage(Throwable exception) {
        if (exception == null) {
            return "无效的错误信息：没有任何错误信息内容";
        }
        
        Throwable firstBusinessException = getFirstBusinessException(exception);
        Throwable firstException = getFirstException(exception);
        String msg = (firstBusinessException == null ? firstException.getMessage() : firstBusinessException.getMessage());
        return msg == null ? "" : msg;
    }

    /**
     * 获取异常发生的原因：寻找第一个发生的异常
     *
     * @param exception Throwable
     * @return Throwable
     */
    private static Throwable getFirstException(Throwable exception) {
        Throwable firstException = exception;
        Throwable cause = exception.getCause();
        while (cause != null) {
            firstException = cause;
            cause = cause.getCause();
        }
        return firstException;
    }

    /**
     * 获取原始自定义异常：寻找第一个自定义的异常
     *
     * @param exception Throwable
     * @return Throwable
     */
    private static Throwable getFirstBusinessException(Throwable exception) {
        Throwable firstBusinessException = null;
        Throwable cause = exception;
        while (cause != null) {
            if (BeanUtil.isImplInterface(cause.getClass(), IBusinessException.class)
                    || cause instanceof UserIdentificationException) {
                firstBusinessException = cause;
            }
            cause = cause.getCause();
        }
        return firstBusinessException;
    }

    /**
     * 获取异常发生的详细信息
     *
     * @param exception
     * @return
     */
    private static String getDescription(Throwable exception) {
        StringBuffer sb = new StringBuffer();
        while (exception != null) {
            if (exception.getMessage() != null) {
                sb.append(exception.getMessage());
            }
            sb.append("\n\tat " + exception.getClass().getName() + "\n");
            exception = exception.getCause();
        }
        return sb.toString();
    }
 
    public String toXml() {
        StringBuffer sb = new StringBuffer();
        sb.append("<?xml version=\"1.0\" encoding=\"" + DEFAULT_ENCODING + "\"?>");
        sb.append("<Response><Error>");
        sb.append("<msg><![CDATA[").append(this.message).append("]]></msg>");
        sb.append("<description><![CDATA[").append(description).append("]]></description>");
        sb.append("<relogin>").append(this.relogin).append("</relogin>");
        sb.append("<type>").append(this.type).append("</type>");
        sb.append("</Error></Response>");
        
        String returnXml = sb.toString();
        log.debug(returnXml);
        return returnXml;
    }

    /**
     * <p>
     * 将错误信息输出成HTML格式
     * </p>
     *
     * @return
     */
    public String toHTML() {
        try {
            StringBuffer sb = new StringBuffer();
            sb.append("<html><head><title>Error Message</title></head><body>");
            sb.append("<script language=\"JavaScript\">\n");
            sb.append("var msg = '" + this.message.replaceAll("\\n", "\\\\n").replaceAll("\n", "\\\\n") + "';\n");
            sb.append("var description = '" + this.description.replaceAll("\\n", "\\\\n").replaceAll("\n", "\\\\n") + "';\n");
            sb.append("if(typeof(alert) == 'function'){\n");
            sb.append("    alert(msg, description);\n");
            sb.append("}else if(parent != null && typeof(parent.alert) == 'function'){\n");
            sb.append("    parent.alert(msg, description);\n");
            sb.append("}else{\n");
            sb.append("    msg = '错误信息：' + msg + '\\n明细信息：\\n' + description;\n");
            sb.append("    alert(msg);\n");
            sb.append("}\n");
            sb.append("</script>");
            sb.append("</body></html>");
            
            String returnHtml = sb.toString();
            log.debug(returnHtml);
            return returnHtml;
            
        } catch (RuntimeException e) {
            e.printStackTrace();
        }
        return "";
    }
 
    public void print(XmlPrintWriter writer) {
        writer.append(toXml());
    }

    public String getMessage() {
        return message;
    }
}