Java连接MySQL数据库
- 配置文件
ClassLoader classLoader = JDBCTools.class.getClassLoader();
URL resource = classLoader.getResource("jdbc.properties");
assert resource != null;
String path = resource.getPath();
prop.load(new FileReader(path));
user = prop.getProperty("user");
password = prop.getProperty("password");
url = prop.getProperty("url");
driver = prop.getProperty("driver");
Class.forName(driver);
- 自己写的连接工具类
public class JDBCTools {
private static String user;
private static String password;
private static String url;
private static String driver;
static {
Properties prop = new Properties();
try {
ClassLoader classLoader = JDBCTools.class.getClassLoader();
URL resource = classLoader.getResource("jdbc.properties");
assert resource != null;
String path = resource.getPath();
prop.load(new FileReader(path));
user = prop.getProperty("user");
password = prop.getProperty("password");
url = prop.getProperty("url");
driver = prop.getProperty("driver");
Class.forName(driver);
} catch (IOException | ClassNotFoundException e) {
e.printStackTrace();
}
}
public static Connection getConnection() throws SQLException {
return DriverManager.getConnection(url,user,password);
}
public static void close(ResultSet res,Statement stmt, Connection conn){
if (res != null){
try {
res.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
if (stmt != null){
try {
stmt.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
if (conn != null){
try {
conn.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
}
}
- 防sql注入
private boolean login(String username, String password) {
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet resultSet = null;
if (username == null || password == null){
return false;
}
try {
conn = JDBCTools.getConnection();
String sql = "select * from user where `username`=? and `password` = ?";
pstmt = conn.prepareStatement(sql);
pstmt.setString(1,username);
pstmt.setString(2,password);
resultSet = pstmt.executeQuery();
return resultSet.next();
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
JDBCTools.close(resultSet,pstmt,conn);
}
return false;
}