javaweb中mysql数据库连接步骤方法及其实例

/*协议：子协议://主机:端口/数据库名*/Stringurl="jdbc:mysql://localhost:3306/jdbctest";//mysql数据库的用户名与密码，安装时自己设置，一般默认为rootStringuser="root";Stringpassword="root";Connectionconnection=null;Statementstatement=null;ResultSetresultSet=null;try{//1.加载驱动//com.mysql.jdbc.Driver/**DriverManager.registerDriver(new*Driver());用这种方法会加载两次驱动，也就是说会创建两个drive对象*/Class.forName("com.mysql.jdbc.Driver");//2.获取连接connection=DriverManager.getConnection(url,user,password);//3.获取用于向数据库发送SQL的Statement对象statement=connection.createStatement();//4.执行sql,获取数据resultSet=statement.executeQuery("SELECT*FROMusers;");//解析数据while(resultSet.next()){intid=resultSet.getInt("id");Stringname=resultSet.getString("name");Stringpsd=resultSet.getString("password");Stringemail=resultSet.getString("email");Stringbirthday=resultSet.getString("birthday");System.out.println(id+""+name+""+psd+""+email+""+birthday);}}catch(ClassNotFoundExceptione){e.printStackTrace();}catch(SQLExceptione){e.printStackTrace();}finally{//5.关闭连接，释放资源if(resultSet!=null){try{resultSet.close();}catch(SQLExceptione){//TODOAuto-generatedcatchblocke.printStackTrace();}resultSet=null;}if(statement!=null){try{statement.close();}catch(SQLExceptione){//TODOAuto-generatedcatchblocke.printStackTrace();}statement=null;}if(connection!=null){try{connection.close();}catch(SQLExceptione){//TODOAuto-generatedcatchblocke.printStackTrace();}connection=null;}/* 协议：子协议://主机:端口/数据库名 */String url = "jdbc:mysql://localhost:3306/jdbctest";// mysql数据库的用户名与密码，安装时自己设置，一般默认为rootString user = "root";String password = "root";Connection connection = null;Statement statement = null;ResultSet resultSet = null;try {  // 1.加载驱动//com.mysql.jdbc.Driver  /*   * DriverManager.registerDriver(new   * Driver());用这种方法会加载两次驱动，也就是说会创建两个drive对象   */  Class.forName("com.mysql.jdbc.Driver");  // 2.获取连接  connection = DriverManager.getConnection(url, user, password);  // 3.获取用于向数据库发送SQL的Statement对象  statement = connection.createStatement();  // 4.执行sql,获取数据  resultSet = statement.executeQuery("SELECT * FROM users;");  // 解析数据  while (resultSet.next()) {int id = resultSet.getInt("id");String name = resultSet.getString("name");String psd = resultSet.getString("password");String email = resultSet.getString("email");String birthday = resultSet.getString("birthday");System.out.println(id + " " + name + " " + psd + " " + email+ " " + birthday);  }} catch (ClassNotFoundException e) {  e.printStackTrace();} catch (SQLException e) {  e.printStackTrace();} finally {     //5.关闭连接，释放资源  if (resultSet != null) {try {  resultSet.close();} catch (SQLException e) {  // TODO Auto-generated catch block  e.printStackTrace();}resultSet = null;  }  if (statement != null) {try {  statement.close();} catch (SQLException e) {  // TODO Auto-generated catch block  e.printStackTrace();}statement = null;  }  if (connection != null) {try {  connection.close();} catch (SQLException e) {  // TODO Auto-generated catch block  e.printStackTrace();}connection = null;  }}

url=jdbc:mysql://localhost:3306/jdbctestusername=rootpassword=rootdriver=com.mysql.jdbc.Driver

importjava.io.IOException;importjava.sql.Connection;importjava.sql.DriverManager;importjava.sql.ResultSet;importjava.sql.SQLException;importjava.sql.Statement;importjava.util.Properties; publicclassJdbcUtil{//私有静态变量，用以读取配置文件privatestaticPropertiesconfig=newProperties();static{try{//配置资源文件config.load(JdbcUtil.class.getClassLoader().getResourceAsStream("db.properties"));//加载驱动Class.forName(config.getProperty("driver"));}catch(IOExceptione){e.printStackTrace();}catch(ClassNotFoundExceptione){e.printStackTrace();}}publicstaticConnectiongetConnection(){Connectionconnection=null;try{connection=DriverManager.getConnection(config.getProperty("url"),config.getProperty("username"),config.getProperty("password"));}catch(SQLExceptione){e.printStackTrace();}returnconnection;}//用以关闭连接，释放资源publicstaticvoidreleaseConn(Connectionconnection,Statementstatement,ResultSetresultSet){if(resultSet!=null){try{resultSet.close();}catch(SQLExceptione){e.printStackTrace();}resultSet=null;}if(statement!=null){try{statement.close();}catch(SQLExceptione){e.printStackTrace();}statement=null;}if(connection!=null){try{connection.close();}catch(SQLExceptione){e.printStackTrace();}connection=null;}} }

Connectionconnection=null;Statementstatement=null;ResultSetresultSet=null;try{//调用工具类中的静态方法来获取连接connection=JdbcUtil.getConnection();statement=connection.createStatement();resultSet=statement.executeQuery("select*fromusers");while(resultSet.next()){intid=resultSet.getInt("id");Stringname=resultSet.getString("name");Stringpsd=resultSet.getString("password");Stringemail=resultSet.getString("email");Stringbirthday=resultSet.getString("birthday");System.out.println(id+""+name+""+psd+""+email+""+birthday); }}catch(Exceptione){e.printStackTrace();}finally{//调用工具类中的静态方法来关闭连接，释放资源JdbcUtil.releaseConn(connection,statement,resultSet);}