通過JDBC連接MySql數據庫

說明：首先配製好java開發環境，然後把MySql的jdbc驅動寫在classpath裏面面，然後先編譯DBManager.java
，之後編譯testcondb.java時，需用-classpath參數把DBManager.class所在目錄地址添加
上去。之後用java testcondb 命令運行，如果配製正確就可以看到結果了。

DBManager.java文件

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: </p>
 * @awolf168
 * @version 1.0
 */
import java.sql.Connection;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;
public class DBManager
{       //需配製web服務器，然後通過數據源來連接
 public static Connection getConnection()
 {
  try {
   InitialContext initx = new InitialContext();
   Context tx = (Context)initx.lookup("java:comp/env");
   DataSource ds = (DataSource) tx.lookup("jdbc/dsmail");
   return ds.getConnection();
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }

  return null;
 }
 //直接用jdbc連接
 public static Connection getNativeConnection() throws Exception
 {
  Class.forName("com.mysql.jdbc.Driver");
  java.sql.Connection conn = java.sql.DriverManager.getConnection(
    "jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=GBK" ,
    "用戶名" , "密碼");
  return conn;
 }
}

testcondb.java文件

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: </p>
 * @awolf168
 * @version 1.0
 */
import java.sql.*;
//連接mysql數據庫測試代碼
public class testcondb{
 public String getTestStr()throws Exception
 {
 Connection con=null;
 ResultSet res=null; 
        PreparedStatement ps=null;
 String id=null;
   try{
                DBManager db=new DBManager();
    con=db.getNativeConnection();
    ps = con.prepareStatement("select * from test.ts");
        res = ps.executeQuery();
        while (res.next())
        {
            id = res.getString("id");
        }
        return id;
   }
       finally{
        try{ 
         res.close();
         ps.close();
         con.close();
        }
        catch(Exception e)
  {
         e.printStackTrace();
  }
       }
   }
  public static void main(String args[]) throws Exception
  {
   testcondb tb=new testcondb();
   System.out.print("test db connection:");
   System.out.print(tb.getTestStr());
  }
}