JDBC实例

JDBC实例

1、通过statement存入一个学生，查询学生

2、通过prestatement存入一个学生

ExamStudent对象类：

package jdbc2;

public class ExamStudent {
	int flowid;
	int type;
	String idcard;
	String examCard;
	String studentname;
	String location;
	int grade;
	public ExamStudent() {
		super();
		// TODO Auto-generated constructor stub
	}
	
	@Override
	public String toString() {
		return "ExamStudent [flowid=" + flowid + ", type=" + type + ", idcard="
				+ idcard + ", examCard=" + examCard + ", studentname="
				+ studentname + ", location=" + location + ", grade=" + grade
				+ "]";
	}
	public int getFlowid() {
		return flowid;
	}
	public void setFlowid(int flowid) {
		this.flowid = flowid;
	}
	public int getType() {
		return type;
	}
	public void setType(int type) {
		this.type = type;
	}
	public String getIdcard() {
		return idcard;
	}
	public void setIdcard(String idcard) {
		this.idcard = idcard;
	}
	public String getExamCard() {
		return examCard;
	}
	public void setExamCard(String examCard) {
		this.examCard = examCard;
	}
	public String getStudentname() {
		return studentname;
	}
	public void setStudentname(String studentname) {
		this.studentname = studentname;
	}
	public String getLocation() {
		return location;
	}
	public void setLocation(String location) {
		this.location = location;
	}
	public int getGrade() {
		return grade;
	}
	public void setGrade(int grade) {
		this.grade = grade;
	}

	public ExamStudent(int flowid, int type, String idcard, String examCard,
			String studentname, String location, int grade) {
		super();
		this.flowid = flowid;
		this.type = type;
		this.idcard = idcard;
		this.examCard = examCard;
		this.studentname = studentname;
		this.location = location;
		this.grade = grade;
	}
}

　　

1、获取数据库连接封装的方法

	public static Connection getConnection() throws Exception{
		String driverClass = null;
		String url = null;
		String user = null;
		String password = null;
		
		//读取properties配置文件
		InputStream is = TestJDBC.class.getClassLoader().getResourceAsStream("jdbc.properties");
		Properties properties = new Properties();
		properties.load(is);
	    driverClass = properties.getProperty("driverClass");
	    url = properties.getProperty("url");
		user = properties.getProperty("user");
		password = properties.getProperty("password");
		
		//加载数据库驱动（对应的Driver实现类中有注册驱动的静态代码块）
		Class.forName(driverClass);
		
		Properties info = new Properties();
		info.put("user", user);
		info.put("password", password);
		
		//通过DriverManager的getConnection()方法获取数据库连接
		return DriverManager.getConnection(url, user, password);
	}

2、释放资源封装的方法

	//释放资源
	public static void release(Statement statement,Connection conn,ResultSet rs){
		if(rs != null){
			try {
				rs.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if(statement!=null){
			try {
				statement.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if(conn != null){
			try {
				conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}

　　

3、简单的学生登录封装的方法

	//登录
	private int getSearchTypeFormConsole(){
		System.out.println("请输入登录类型：1：身份证登录  2.准考证号登陆");
		Scanner sc = new Scanner(System.in);
		int type = sc.nextInt();
		if(type != 1 && type != 2){
			throw new RuntimeException("输入类型有误");
		}
		
		return type;
	}

　　

4、创建查询语句

	public String SearchStudent(int type){
		ExamStudent es = new ExamStudent();
		Scanner sc = new Scanner(System.in);
		String sql = "select * from ExamStudent where idcard = " ;
		if(type == 1){
			System.out.println("请输入身份证号");
			
			String idcard = sc.next();
			es.setIdcard(idcard);
			sql = sql + es.getIdcard();
		}else{
			System.out.println("请输入准考证号");
			String examcard = sc.next();
			es.setExamCard(examcard);
			sql = sql + es.getExamCard();
		}
		return sql;
		
	}

　　

5、查询学生

public ExamStudent getStudent(String sql){
		Connection conn = null;
		Statement statement = null;
		ResultSet rs = null;
		ExamStudent es = null;
		
		try {
			conn = getConnection();
			statement = conn.createStatement();
			rs = statement.executeQuery(sql);
			
			while(rs.next()){
				es = new ExamStudent(
						rs.getInt(1),
						rs.getInt(2),
						rs.getString(3),
						rs.getString(4),
						rs.getString(5),
						rs.getString(6),
						rs.getInt(7));
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			release(statement, conn, rs);
		}
		return es;	
	}

　　

6、输出学生

	public void printStudent(ExamStudent es){
		if(es !=null){
			System.out.println(es);
		}else{
			System.out.println("查无此人！！！");
		}
	}

　　

7、测试

	@Test
	public void test1() throws Exception{
		//1.登录
		int type = getSearchTypeFormConsole();
		
		//获取信息
		String sql = SearchStudent(type);
		
		//查询
		ExamStudent es = getStudent(sql);
		
		//输出
		printStudent(es);
	}

　　

8、从控制台输入ExamStudent对象

	//从控制台输入ExamStudent对象
	public ExamStudent getExamStudentFromConsole(){
		ExamStudent es = new ExamStudent();
		Scanner sc = new Scanner(System.in);
		System.out.println("学生号： ");
		es.flowid = sc.nextInt();
		System.out.println("考试类型： ");
		es.type = sc.nextInt();
		System.out.println("身份证： ");
		es.idcard = sc.next();
		System.out.println("考号： ");
		es.examCard = sc.next();
		System.out.println("学生名： ");
		es.studentname = sc.next();
		System.out.println("学生地址： ");
		es.location = sc.next();
		System.out.println("学生班级： ");
		es.grade = sc.nextInt();
		return es;
	}

　　

9、封装的sql语句修改、插入、删除方法

	public void update(String sql){
		Connection conn = null;
		Statement statement = null;
		ResultSet rs = null;
		try {
			conn = getConnection();
			statement = conn.createStatement();
			statement.executeUpdate(sql);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			TestJDBC.release(statement, conn,rs);
		}
	}

　　

10、添加学生

	//添加学生到数据库
	public void addStudent(){
		ExamStudent stu  = getExamStudentFromConsole();
		String sql = "insert into examstudent values(" + stu.getFlowid() +"," + stu.getType() + ",'" + stu.getIdcard() + "','" + stu.getExamCard() + "','" + stu.getStudentname() + "','" + stu.getLocation() + "'," + stu.getGrade() + ")";
		update(sql);
		System.out.println("插入成功！！！！");
	}
	

　　

通过Prestatement存入学生数据

1、从控制台得到需要插入的学生信息

	//从控制台输入ExamStudent对象
	public ExamStudent getExamStudentFromConsole(){
		ExamStudent es = new ExamStudent();
		Scanner sc = new Scanner(System.in);
		System.out.println("学生号： ");
		es.flowid = sc.nextInt();
		System.out.println("考试类型： ");
		es.type = sc.nextInt();
		System.out.println("身份证： ");
		es.idcard = sc.next();
		System.out.println("考号： ");
		es.examCard = sc.next();
		System.out.println("学生名： ");
		es.studentname = sc.next();
		System.out.println("学生地址： ");
		es.location = sc.next();
		System.out.println("学生班级： ");
		es.grade = sc.nextInt();
		return es;
	}

　　

2、获取数据库连接

	//获取数据库连接方法
	public static Connection getConnection() throws Exception{
		String driverClass = null;
		String url = null;
		String user = null;
		String password = null;
		
		//读取properties配置文件
		InputStream is = TestJDBC.class.getClassLoader().getResourceAsStream("jdbc.properties");
		Properties properties = new Properties();
		properties.load(is);
	    driverClass = properties.getProperty("driverClass");
	    url = properties.getProperty("url");
		user = properties.getProperty("user");
		password = properties.getProperty("password");
		
		//加载数据库驱动（对应的Driver实现类中有注册驱动的静态代码块）
		Class.forName(driverClass);
		
		Properties info = new Properties();
		info.put("user", user);
		info.put("password", password);
		
		//通过DriverManager的getConnection()方法获取数据库连接
		return DriverManager.getConnection(url, user, password);
	}

　　

3、通过prestatement进行数据插入

	//重写update方法
	public void update(String sql,Object...args){
		Connection conn = null;
		PreparedStatement preparedStatement = null;
		
		try {
			conn = getConnection();
			preparedStatement = conn.prepareStatement(sql);
			
			for(int i=0;i<args.length;i++){
				preparedStatement.setObject(i+1, args[i]);
			}
			int result = preparedStatement.executeUpdate();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

　　

4、添加学生

	//添加学生
	public void addStudent2(ExamStudent es){
		String sql = "insert into examstudent(flowid,type,idcard,examcard,studentname,location,grade) values(?,?,?,?,?,?,?)";
		update(sql,es.getFlowid(),es.getType(),es.getIdcard(),es.getExamCard(),es.getStudentname(),es.getLocation(),es.getGrade());
	}

　　

5、进行测试

@Test
	public void test3(){
		ExamStudent es = getExamStudentFromConsole();
		addStudent2(es);
	}