/// <summary>
/// 单连续字串（不带空格符）单Field查询分析
/// </summary>
/// <param name="field"></param>
/// <param name="query"></param>
/// <returns></returns>
public static Query Parse(String field, String query)
{
if (field == null)
{
throw new ArgumentException("parameter \"field\" is null");
}
if (query == null || "".Equals(query.Trim()))
{
return new TermQuery(new Term(field));
}
//从缓存中取出已经解析的query生产的TokenBranch
TokenBranch root = GetCachedTokenBranch(query);
if (root != null)
{
return OptimizeQueries(root.ToQueries(field));
}
else
{
//System.out.println(System.currentTimeMillis());
root = new TokenBranch(null);
//对查询条件q进行分词
StringReader input = new StringReader(query.Trim());
IKSegmentation ikSeg = new IKSegmentation(input, isMaxWordLength);
try
{
for (Lexeme lexeme = ikSeg.Next(); lexeme != null; lexeme = ikSeg.Next())
{
//处理词元分支
root.Accept(lexeme);
}
}
catch (IOException e)
{
Console.WriteLine(e.StackTrace);
}
//缓存解析结果的博弈树
CachedTokenBranch(query, root);
return OptimizeQueries(root.ToQueries(field));
}
}
///<summary>
///组合词元分支
/// </summary>
/// <returns>返回当前branch能否接收词元对象</returns>
public bool Accept(Lexeme _lexeme)
{
/*
* 检查新的lexeme 对当前的branch 的可接受类型
* acceptType : REFUSED 不能接受
* acceptType : ACCEPTED 接受
* acceptType : TONEXT 由相邻分支接受
*/
int acceptType = CheckAccept(_lexeme);
switch (acceptType)
{
case REFUSED:
// REFUSE 情况
return false;
case ACCEPTED:
if (acceptedBranchs == null)
{
//当前branch没有子branch，则添加到当前branch下
acceptedBranchs = new List<TokenBranch>(2);
acceptedBranchs.Add(new TokenBranch(_lexeme));
}
else
{
bool acceptedByChild = false;
//当前branch拥有子branch，则优先由子branch接纳
foreach (TokenBranch childBranch in acceptedBranchs)
{
acceptedByChild = childBranch.Accept(_lexeme) || acceptedByChild;
}
//如果所有的子branch不能接纳，则由当前branch接纳
if (!acceptedByChild)
{
acceptedBranchs.Add(new TokenBranch(_lexeme));
}
}
//设置branch的最大右边界
if (_lexeme.EndPosition > this.rightBorder)
{
this.rightBorder = _lexeme.EndPosition;
}
break;
case TONEXT:
//把lexeme放入当前branch的相邻分支
if (this.nextBranch == null)
{
//如果还没有相邻分支，则建立一个不交叠的分支
this.nextBranch = new TokenBranch(null);
}
this.nextBranch.Accept(_lexeme);
break;
}
return true;
}
/// <summary>
/// 缓存解析结果的博弈树
/// </summary>
/// <param name="query"></param>
/// <param name="tb"></param>
private static void CachedTokenBranch(String query, TokenBranch tb)
{
Dictionary<String, TokenBranch> keywordCache = GetTheadLocalCache();
keywordCache.Add(query, tb);
}
