package com.ctrip.apollo.util;

 import com.google.common.base.Strings;

 import com.google.common.collect.Lists;

 import java.util.List;

 /**

  * @author Jason Song(song_s@ctrip.com)

  */

 public class ExceptionUtil {

   /**

    * Assemble the detail message for the throwable with all of its cause included (at most 10 causes).

    * @param ex the exception

    * @return the message along with its causes

    */

   public static String getDetailMessage(Throwable ex) {

     if (ex == null || Strings.isNullOrEmpty(ex.getMessage())) {

       return "";

     }

     StringBuilder builder = new StringBuilder(ex.getMessage());

     List<Throwable> causes = Lists.newLinkedList();

     int counter = 0;

     Throwable current = ex;

     //retrieve up to 10 causes

     while (current.getCause() != null && counter < 10) {

       Throwable next = current.getCause();

       causes.add(next);

       current = next;

       counter++;

     }

     for (Throwable cause : causes) {

       if (Strings.isNullOrEmpty(cause.getMessage())) {

         counter--;

         continue;

       }

       builder.append(" [Cause: ").append(cause.getMessage());

     }

     builder.append(Strings.repeat("]", counter));

     return builder.toString();

   }

 }