4月 2009

CKIP 中文斷詞系統是由中文詞知識庫小組（Chinese Knowledge Information Processing Group，CKIP）所發展的線上斷詞服務。此服務採用 XML 資料交換模式，用戶端必須自行撰寫程式經由 TCP Scoket 傳送文本到斷詞系統，並剖析回傳包含斷詞及詞類標記的 XML 處理結果。

目前，CKIP Client 開放原始碼專案已實作 Java、PHP 兩種版本，可以用來簡化 CKIP 斷詞服務用戶端應用程式的開發，而不需自行撰寫 Socket 程式碼及處理 XML 資料。而本文的 CKIP Client for .NET 則是自己重新以 C# 實作 CLR 非同步程式撰寫模型（Asynchronous Programming Model）所設計的斷詞服務用戶端 APIs。

使用範例
下列範例會使用 CkipClient 在同步封鎖模式進行連接、傳送文本，並接收傳回結果，其中 username 及 password 為用戶端所申請之帳號及密碼。

using (CkipClient client = new CkipClient("username", "password"))
{
    client.Send("菩提本無樹，明鏡亦非臺；本來無一物，何處惹塵埃？");
    SegmentationResult result = client.GetResult();

    if (result.StatusCode == StatusCode.Success)
    {
        StringBuilder sb = new StringBuilder();
        foreach (Term term in result.GetTerms())
        {
            sb.Append(term.ToString() + "　");
        }
        Console.WriteLine(sb.ToString());
    }
    else
    {
        Console.WriteLine(string.Format("Error: {0}", result.StatusDescription));
    }
}

輸出結果如下：

菩提(N)　本無樹(N)　，(COMMACATEGORY)　明鏡(N)　亦(ADV)　非(Vt)　臺(N)　；(SEMICOLONCATEGORY)　本來(ADV)　無(Vt)　一(DET)　物(N)　，(COMMACATEGORY)　何處(N)　惹(Vt)　塵埃(N)　？(QUESTIONCATEGORY)

非同步 API 使用範例

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using System.Windows.Forms;
using CKIP;

namespace AsyncCkipClient
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private void uxSend_Click(object sender, EventArgs e)
        {
            CkipClient client = new CkipClient();            
            client.BeginConnect(uxUsername.Text, uxPassword.Text, 
                new AsyncCallback(EndConnectCallback), client);
            DisplayStatus("Connecting to server ...");
        }

        private void EndConnectCallback(IAsyncResult ar)
        {
            CkipClient client = (CkipClient)ar.AsyncState;
            
            try
            {
                client.EndConnect(ar);

                if (client.Connected)
                {
                    client.BeginSend(uxRawText.Text, 
                        new AsyncCallback(EndSendCallback), client);
                    DisplayStatus("Sending data to server ...");             
                }
                else
                {
                    DisplayStatus(string.Format("Ready (last error: {0})", "Connect Failed!"));
                }
            }
            catch (Exception ex)
            {
                client.Close();
                DisplayStatus(string.Format("Ready (last error: {0})", ex.Message));
            }
        }

        private void EndSendCallback(IAsyncResult ar)
        {
            CkipClient client = (CkipClient)ar.AsyncState;

            try
            {
                client.EndSend(ar);                
                client.BeginGetResult(new AsyncCallback(EndGetResultCallback), client);
                DisplayStatus("Reading server response ...");
            }
            catch (Exception ex)
            {
                client.Close();
                DisplayStatus(string.Format("Ready (last error: {0})", ex.Message));
            }
        }

        private void EndGetResultCallback(IAsyncResult ar)
        {
            CkipClient client = (CkipClient)ar.AsyncState;
            try
            {
                SegmentationResult result = client.EndGetResult(ar);

                if (result.StatusCode == StatusCode.Success)
                {
                    StringBuilder sb = new StringBuilder();
                    foreach (Term term in result.GetTerms())
                    {
                        sb.Append(term.ToString() + "　");
                    }
                    DisplayResults(sb.ToString());
                }
                else
                {                    
                    DisplayStatus(string.Format("Ready (last error: {0})", 
                        result.StatusDescription));
                }                
            }
            catch (Exception ex)
            {                
                DisplayStatus(string.Format("Ready (last error: {0})", ex.Message));
            }
            finally
            {
                client.Close();
            }
        }

        public void DisplayResults(string text)
        {
            if (InvokeRequired)
            {
                BeginInvoke(new Action<string>(DisplayResults), text);
                return;
            }
            uxResult.Text = text;
            DisplayStatus("Done");
        }

        public void DisplayStatus(string text)
        {
            if (InvokeRequired)
            {
                BeginInvoke(new Action<string>(DisplayStatus), text);
                return;
            }
            uxStatus.Text = text;
        }        
    }
}