JDBC用ConnectionFactory創建數據庫連接

數據庫準備

一、創建jdbcinfo.properties配置文件

可以在文件內輸入不同的數據庫配置數據，這裏以Sqlite數據爲例

sqlite.driver=org.sqlite.JDBC
sqlite.url=jdbc:sqlite:E:/SQLite3/StudentManageSystem.db
sqlite.user=
sqlite.password=

oracle.driver=oracle.jdbc.driver.OracleDriver
oracle.url=jdbc:oracle:thin:@" + "host:port:databaseName
oracle.user=**
oracle.password=**

mysql.driver=com.mysql.jdbc.Driver
mysql.url=jdbc:mysql://host:port:databaseName
mysql.user=**
mysql.password=**

二、創建ConnectionFactory類

package com.cjx913;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

public class ConnectionFactory {
	private static String DRIVER;
	private static String URL;
	private static String USER;
	private static String PASSWORD;
	
	static{
		Properties properties = new Properties();
		InputStream is = 
				ConnectionFactory.class.getResourceAsStream("jdbcinfo.properties");
		try {
			properties.load(is);//加載配置文件
			DRIVER = properties.getProperty("sqlite.driver");//讀取文件配置數據庫驅動
			URL = properties.getProperty("sqlite.url");//讀取文件配置數據庫URL
			USER = properties.getProperty("sqlite.user");//讀取文件配置數據庫用戶
			PASSWORD = properties.getProperty("sqlite.password");//讀取文件配置數據庫用戶密碼
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
	
	/**
	 * 提供getConnection()方法
	 * @return Connection
	 */
	public static Connection getConnection(){
		Connection conn = null;
		try {
			Class.forName(DRIVER);
			conn = DriverManager.getConnection(URL);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}
		
		return conn;
	}

}

三、創建Student類

package com.cjx913;

public class Student {

	private int id;
	private String name;
	private String stu_class;

	public Student() {
		super();
	}

	public Student(int id, String name,String stu_class) {
		super();
		this.id = id;
		this.name = name;
		this.stu_class = stu_class;
	}

	public String getStu_class() {
		return stu_class;
	}

	public void setStu_class(String stu_class) {
		this.stu_class = stu_class;
	}

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name +", class=" + stu_class + "]";
	}

}

四、讀取數據庫測試類Test

package com.cjx913;

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

public class test {

	public static void main(String[] args) {
		List<Student> list = fecthData();

		for (Student s : list) {
			System.out.println(s);
		}
		
		
		insertData(13, "z", "6");
		

	}

	private static void insertData(int id,String name,String stu_class){
		Connection conn = null;
		PreparedStatement ps = null;
		boolean isExist = false;
		conn = ConnectionFactory.getConnection();
		try {
			ps = conn.prepareStatement("SELECT id FROM Student");
			ResultSet rs = ps.executeQuery();
			while(rs.next()){
				if(rs.getInt(1)==id){
					isExist = true;
				
				}
			}
			if(!isExist){
				ps = conn.prepareStatement("INSERT INTO Student VALUES(?,?,?)");
				ps.setInt(1, id);
				ps.setString(2, name);
				ps.setString(3, stu_class);
				ps.executeUpdate();
				System.out.println("Insert Succeed!");
			}
		} catch (SQLException e) {
			try {
				conn.rollback();
			} catch (SQLException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
			e.printStackTrace();
		}finally{
			if (conn != null) {
				try {
					conn.close();
				} catch (SQLException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}
	
	private static List<Student> fecthData() {
		Student student = null;
		List<Student> list = new ArrayList<Student>();
		Connection conn = ConnectionFactory.getConnection();
		try {
			
			PreparedStatement ps = conn.prepareStatement("SELECT * FROM Student");
			ResultSet rs = ps.executeQuery();
			while (rs.next()) {
				student = new Student();
				student.setId(rs.getInt(1));
				student.setName(rs.getString(2));
				student.setStu_class(rs.getString(3));
				list.add(student);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (conn != null) {
				try {
					conn.close();
				} catch (SQLException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		return list;
	}

}