Spring Problem

public class Problem {

   /**
    * 问题信息
    */
   private final String message;

   /**
    * 问题发生的地方
    */
   private final Location location;

   /**
    * 状态, 存储堆栈信息. 
    */
   @Nullable
   private final ParseState parseState;

   /**
    * 异常
    */
   @Nullable
   private final Throwable rootCause;
}

public final class ParseState {

   /**
    * Tab character used when rendering the tree-style representation.
    */
   private static final char TAB = '\t';

   /**
    * Internal {@link LinkedList} storage.
    * 存储每个阶段的 Entry 对象
    */
   private final LinkedList<Entry> state;
    
    
    public String toString() {
		StringBuilder sb = new StringBuilder();
		for (int x = 0; x < this.state.size(); x++) {
			if (x > 0) {
				sb.append('\n');
				for (int y = 0; y < x; y++) {
					sb.append(TAB);
				}
				sb.append("-> ");
			}
			sb.append(this.state.get(x));
		}
		return sb.toString();
	}
}

public class Location {
   /**
    * 资源对象
    */
   private final Resource resource;

   /**
    * 源数据
    */
   @Nullable
   private final Object source;
}