建立connection連結，釋放關閉連結

package demo.untils;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class JDBCUtils {

	private static String driver="oracle.jdbc.OracleDriver";
	private static String url="jdbc:oracle:thin:@127.0.0.1:1521:orcl";
	private static String user="scott";
	private static String password="tiger";
	//註冊資料庫的驅動
	static{
		try {
			Class.forName(driver);//採用java反射機制，必然會丟擲異常
			//DriverManager.registerDriver(driver);//一般不採用java提供的這個方法註冊驅動
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	//獲取資料庫連結
	public static Connection getConnection(){
		try {
			return DriverManager.getConnection(url, user, password);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return null;//如果不成功，測沒有獲取資料庫的連結
	}
	//釋放資料庫的資源
	public static void release(Connection conn,Statement st,ResultSet rs){
		if(rs!=null){
			try {
				rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}finally{
				rs=null;//讓rs迅速成為java垃圾回收的物件
			}
		}
		if(st!=null){
			try {
				st.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}finally{
				st=null;
			}
		}
		if(conn!=null){
			try {
				conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}finally{
				conn=null;
			}
		}
	}
    
}
 

package demo.oracle;

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.SQLException;

import oracle.jdbc.OracleTypes;
import org.junit.Test;

import demo.untils.JDBCUtils;

public class TestProcedure {

	/*
	 *create or replace procedure queryempinform(eno in number,
                                           pename out varchar2,
                                           psal out number,
                                           pjob out varchar2)
	 */
	@Test
	public void testprocedure(){
		//{call <procedure-name>[(<arg1>,<arg2>, ...)]}
        String sql = "{call queryempinform(?,?,?,?)}";
        Connection conn =null;
        CallableStatement call =null;
        
        try {
        	//得到一個連結
        	conn=JDBCUtils.getConnection();
        	//通過連結創建出statement
			call=conn.prepareCall(sql);
			
			//對於in引數，賦值
			call.setInt(1, 7839);
			
			//對於out引數 ，宣告
			call.registerOutParameter(2, OracleTypes.VARCHAR);
			call.registerOutParameter(3, OracleTypes.NUMBER);
			call.registerOutParameter(4, OracleTypes.VARCHAR);
			
			//執行呼叫
			call.execute();
			
			//取出結果
			String name = call.getString(2);
			double salary = call.getDouble(3);
			String job = call.getString(4);
			System.out.println(name+"\t"+salary+"\t"+job);
			
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			JDBCUtils.release(conn, call,null);
		}
	}
}
 

package demo.oracle;

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.SQLException;

import oracle.jdbc.OracleTypes;

import org.junit.Test;

import demo.untils.JDBCUtils;

public class TestFunction {
/*
 create or replace function queryempincome(eno in number)
return number
 */
	@Test
	public void testFunction(){
		//{?= call <procedure-name>[(<arg1>,<arg2>, ...)]}
        String sql ="{?= call queryempincome(?)}";
        Connection conn = null;
        CallableStatement call= null;
        
        try {
        	//得到資料庫連結
        	conn=JDBCUtils.getConnection();
        	//基於連結建立statement
			call = conn.prepareCall(sql);
			
			//對於輸出引數，宣告
			call.registerOutParameter(1, OracleTypes.NUMBER);
			//對於輸入引數，賦值
			call.setInt(2, 7839);
			
			//執行呼叫
			call.execute();
			
			//取出年收入的結果（儲存函式的結果）
			double income = call.getDouble(1);
			System.out.println("該員工的年收入是："+income);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			JDBCUtils.release(conn, call, null);
		}
	}
}
 

package demo.oracle;

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;

import oracle.jdbc.OracleCallableStatement;
import oracle.jdbc.OracleTypes;

import org.junit.Test;

import demo.untils.JDBCUtils;

public class TestCursor {
/*
 create or replace PACKAGE MYPACKAGE AS 

  type empcursor is ref cursor;
  procedure queryEmpList(dno in number,empList out empcursor);
END MYPACKAGE;
 */
	@Test
	public void testcursor(){
		//{call <procedure-name>[(<arg1>,<arg2>, ...)]}
		String sql = "{call MYPACKAGE.queryEmpList(?,?)}";
		Connection conn = null;
		CallableStatement call = null;
		ResultSet rs = null;
		
		try {
			//建立資料庫連結
			conn = JDBCUtils.getConnection();
			//基於連結建立statement
			call = conn.prepareCall(sql);
			
			//對於in引數， 賦值
			call.setInt(1, 20);
			
			//對於out，引數，宣告
			call.registerOutParameter(2, OracleTypes.CURSOR);
			
			//執行呼叫
			call.execute();
			
			//取出該部門的所有員工資訊
			//所有介面都有實現類，不同的是將sql java的介面轉換成oracle資料庫的介面
			rs = ((OracleCallableStatement)call).getCursor(2);
			
			while(rs.next()){
				//取出該員工的工號,姓名，薪水，職位
				int empno = rs.getInt("empno");
				String name = rs.getString("ename");
				double salary = rs.getDouble("sal");
				String job = rs.getString("empjob");
				System.out.println(empno+"\t"+name+"\t"+salary+"\t"+job);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			JDBCUtils.release(conn, call, rs);
		}
	}
}