Oracle Java Source and function to call Java

Create Java Source

 

create or replace and compile java source named firstjava as
import oracle.sql.*;
import java.io.*;
import oracle.jdbc.driver.*;
import java.sql.*; 
public class FirstJava
{

   /*
   * 测试方法1,没有数据库交互
   */
   public static String hello(String yourName)
   {
      return "Hello world "+yourName;
   }
   
   /*
   * 测试方法2，同数据库有交互，
   * 注意该方法中获得OracleDriver 和 Connection的方法同标准Java的区别
   * 标准JDBC中的调用方法应该如下：
   *   //获得数据库连接
*     java.lang.Class.forName(\"oracle.jdbc.driver.OracleDriver\");
*    con = DriverManager.getConnection(\"jdbc:oracle:thin:scott/tiger@localhost:1521:LEGDB\");
   */
   
    public static String get_current_time()
    {
        String current_time="";
        OracleDriver driver = new OracleDriver();
        Connection connection=null;
        Statement stmt=null;
        try {
            connection = DriverManager.getConnection("jdbc:default:connection:");
            //connection = driver.defaultConnection();
            stmt = connection.createStatement();
            String cmd =
            "select to_char(sysdate,'YYYY-MM-DD HH24:MI:SS') from dual";
            
            ResultSet rs=stmt.executeQuery(cmd);   
            
            if(rs.next()){
                  current_time=rs.getString(1);
            }
            rs.close();
      
        } catch (SQLException e) {
               System.out.println(" There is an error  " + e);
        }finally {
          try{
            if (stmt != null) stmt.close();
            if (connection != null) connection.close();
           }catch(Exception ee){}
        }
        return current_time;
    }
}

 

 

Create function

create or replace function MY_HELLO(v_name in varchar2) return VARCHAR2 as
language java name 'FirstJava.hello(java.lang.String) return java.lang.String';