整個小案例：整合了Java socket程式設計、jdbc知識（ORM/DAO）

建立資料庫和表，準備表資料（MySQL）

首先建立一個數據庫android
然後建立一個表dictionary，欄位：
id int
receive varchar(100)
response varchar(100)

receive 表示受到的資訊
response 表示迴應的資訊

create database android;

use android;

create table dictionary(
   id int AUTO_INCREMENT,
   receive varchar
 
(100),
   response varchar(100),
   PRIMARY KEY (id)
)  DEFAULT CHARSET=utf8;

insert into dictionary values(null,'你好','好你妹！');
insert into dictionary values(null,'你叫什麼','你想泡我啊？');
insert into dictionary values(null,'你叫什麼','同志，不約');
insert into dictionary values(null,'打你哦','來啊，來打我啊');

物件設定（ORM）

ORM物件關係對映，設定物件對應資料庫中的各欄位。

package socket;

public class Dictionary {
    public int id;
    public String receive;  // 接收
    public String response; // 迴應
}

資料訪問物件（DAO）

package socket;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import
 
 java.util.ArrayList;
import java.util.List;

public class DictionaryDAO {

    public DictionaryDAO() {
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    public Connection getConnection() throws SQLException {
        return DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/android?characterEncoding=UTF-8", "root",
                "admin");
    }

    public List<Dictionary> query(String recieve) {
        List<Dictionary> ds = new ArrayList<Dictionary>();

        String sql = "select * from dictionary where receive = ? ";

        try (Connection c = getConnection(); PreparedStatement ps = c.prepareStatement(sql);) {
            ps.setString(1, recieve);
            ResultSet rs = ps.executeQuery();
            while (rs.next()) {
                Dictionary d = new Dictionary();
                int id = rs.getInt(1);
                String receive = rs.getString("receive");
                String response = rs.getString("response");
                d.id = id;
                d.receive = receive;
                d.response = response;
                ds.add(d);
            }
        } catch (SQLException e) {

            e.printStackTrace();
        }
        return ds;
    }
}

此處，如果不是程式碼編寫問題，出現jdbc錯誤，請注意是否開啟MySQL資料庫。

server端

主要是正常的socket入門程式設計。
通過輸入流收到Client端發來的資料（列印），然後查詢語料對話庫，查到返回正常對話，查不到表示聽不懂。

package socket;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Server {

    private static List<String> cannotUnderstand= new ArrayList<>();
    static{
        cannotUnderstand.add("聽求不懂啊");
        cannotUnderstand.add("說人話");
        cannotUnderstand.add("再說一遍？");
        cannotUnderstand.add("大聲點");
        cannotUnderstand.add("老子在忙，一邊玩兒去");
    }
    public static void main(String[] args) {
        try {

            ServerSocket ss = new ServerSocket(8888);

            System.out.println("監聽在埠號:8888");
            Socket s = ss.accept();

            InputStream is = s.getInputStream();
            DataInputStream dis = new DataInputStream(is);
            OutputStream os = s.getOutputStream();
            DataOutputStream dos = new DataOutputStream(os);

            while (true) {
                String msg = dis.readUTF();
                System.out.println(msg);

                List<Dictionary> ds= new DictionaryDAO().query(msg);
                String response = null;
                if(ds.isEmpty()){
                    Collections.shuffle(cannotUnderstand);
                    response = cannotUnderstand.get(0);
                }
                else{
                    Collections.shuffle(ds);
                    response = ds.get(0).response;
                }
                dos.writeUTF(response);
            }

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
}

Client端

正常的收發資訊

package socket;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;

public class Client {
    public static void main(String[] args) {
        try {
            // 連線到本機的8888埠
            Socket s = new Socket("127.0.0.1", 8888);
            //
            OutputStream os = s.getOutputStream();
            DataOutputStream dos = new DataOutputStream(os);
            InputStream is = s.getInputStream();
            DataInputStream dis = new DataInputStream(is);

            while (true) {
                Scanner sc = new Scanner(System.in);
                String str = sc.next();
                dos.writeUTF(str);
                String msg = dis.readUTF();
                System.out.println(msg);
            }
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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