MySQL建立一个连接工具类

public class DBUtil {
public static Connection getConn() {
Connection conn = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/bbs", "root", "root");
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}

public static PreparedStatement prepareStmt(Connection conn, String sql) {
PreparedStatement pstmt = null;
try {
pstmt = conn.prepareStatement(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return pstmt;
}

public static ResultSet executeQuery(Statement stmt, String sql) {
ResultSet rs = null;
try {
rs = stmt.executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}

public static void close(Connection conn, Statement stmt,
PreparedStatement preStatement, ResultSet rs) {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if (preStatement != null) {
try {
preStatement.close();
} catch (SQLException e) {
e.printStackTrace();
}
preStatement = null;
}

if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
rs = null;
}
}
}