JDBC初体验

 1 import java.sql.Connection;
 2 import java.sql.DriverManager;
 3 import java.sql.ResultSet;
 4 import java.sql.SQLException;
 5 import java.sql.Statement;
 6 
 7 
 8 import com.mysql.jdbc.Driver;
 9 
10 public class Demo02_JDBCTest {
11 　　public static void main(String[] args) throws Exception {
12 //1、导入外部jar包，mysql-connector-java,相当与驱动
13 
14 //2、注册驱动
15 　　Driver driver = new com.mysql.jdbc.Driver();
16 　　DriverManager.registerDriver(driver);
17 
18 //3、创建连接,其中getConnection重载了三种方法，具体参照API
19 　　String url = "jdbc:mysql://localhost:3306/db_demo1?user=root&password=root";
20 　　Connection conn = DriverManager.getConnection(url);
21 
22 //4、得到执行sql语句的Statement对象
23 　　Statement stmt = conn.createStatement();
24 
25 //5、执行sql语句，返回结果
26 　　String sql = "select * from stu";
27 　　ResultSet rs = stmt.executeQuery(sql);    //结果集
28 
29 　　while(rs.next()) {
30 　　for(int i = 1; i <= 4; i++) {
31 　　System.out.print(rs.getObject(i) + " " );
32 　　}
33 　　System.out.println();
34 　　System.out.println("-----------------");
35 　　}
36 //6、关闭资源
37 　　rs.close();
38　　 stmt.close();
39 　　conn.close();
40 　　}
41 }

 1     //读取配置文件信息
 2     ResourceBundle rb = ResourceBundle.getBundle("dbinfo");
 3     driverClass = rb.getString("driverClass");
 4     url = rb.getString("url");
 5     username = rb.getString("username");
 6     password = rb.getString("password"); 
 7      //利用反射对类名进行实例化
 8     Class.forName(driverClass);
 9     //连接数据库
10     conn = DriverManager.getConnection(url, username, password);
11     stmt = conn.createStatement();

 1 public class User {
 2         private int id;
 3         private String name;
 4         private String password;
 5         private String email;
 6         private Date brithday;
 7             
 8         public int getId() {
 9             return id;
10         }
11 
12         public void setId(int id) {
13             this.id = id;
14         }
15         public String getName() {
16             return name;
17         }
18         public void setName(String name) {
19             this.name = name;
20         }
21         public String getPassword() {
22             return password;
23         }
24         public void setPassword(String password) {
25             this.password = password;
26         }
27         public String getEmail() {
28             return email;
29         }
30         public void setEmail(String email) {
31             this.email = email;
32         }
33         public Date getBrithday() {
34             return brithday;
35         }
36         public void setBrithday(Date brithday) {
37             this.brithday = brithday;
38         }
39 
40         @Override
41         public String toString() {
42             return "User [id=" + id + ", name=" + name + ", password="
43                     + password + ", email=" + email + ", brithday=" + brithday
44                     + "]";
45         }
46                 
47 }

    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;
    conn = DBUtils.getConnection();
    stmt = conn.createStatement();
    rs = stmt.executeQuery("select * from user1");
    List<User> list = new ArrayList<User>();
    while(rs.next()) {
    User u = new User();
    u.setId(rs.getInt(1));
    u.setName(rs.getString("name"));        
    //可以利用索引找数据库中的字段，也可以利用名称相同的条件来找
    u.setPassword(rs.getString("password"));
    u.setEmail(rs.getString(4));
    u.setBrithday(rs.getDate(5));
    list.add(u);
    }
                
    for (User user : list) {
        System.out.println(user);
    }