web后台中用jdbc连接mysql

具体操作步骤如下：

    1. 新建java文件，写连接DB和关闭DB的方法;

private String driverName = "com.mysql.jdbc.Driver";
private String userName = "test";
private String userPwd = "111111";
private String dbName = "dbName";

private String url = "jdbc:mysql://xxx/" + dbName + "?user="
+ userName + "&password=" + userPwd + "&characterEncoding=utf-8";
//private String url = "jdbc:mysql://xxx/" + dbName + "?characterEncoding=utf-8";

public Connection conn = null;
public Statement sm = null;
public void ConnectDB() {
try {
Class.forName(driverName).newInstance();
conn = DriverManager.getConnection(url);
//conn = DriverManager.getConnection(url, userName, userPwd);
sm = conn.createStatement();
} catch (Exception ex) {
ex.printStackTrace();
}
}

public void CloseDB() {
try {
if (sm != null) {
sm.close();
}
conn.close();
} catch (SQLException ex) {
ex.printStackTrace();
}
}

    2. 在需要使用数据的地方;

XXXDb db = new XXXDb();
db.ConnectDB();
Connection conn = db.conn;
String sql = "xxxx";
PreparedStatement pstmt = conn.prepareStatement(sql);
ResultSet rs = pstmt.executeQuery();
while(rs.next()) {
String module = rs.getString("xxx");
......
}