java数据库JDBC

JDBCUUtils.java

package jdbc02;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class jdbcUtils {
	private static final String connectionURL="jdbc:mysql://localhost:3306/web01?"
			+ "useUnicode&characterEnding=UTF8&useSSL=false";
	private static final String username="root";
	private static final String password="root";
	
	public static Connection getconnection() {
		try {
			//注册驱动
			Class.forName("com.mysql.jdbc.Driver");
			//建立连接
			return DriverManager.getConnection(connectionURL, username, password);
		} catch (Exception e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		}
		return null;	
	}

	public static void close(ResultSet resultSet,Statement statement,Connection connection) {
		if(resultSet!=null) {
			try {
				resultSet.close();
			} catch (SQLException e) {
				// TODO 自动生成的 catch 块
				e.printStackTrace();
			}
		}		
		if(statement!=null)
			try {
				statement.close();
			} catch (SQLException e) {
				// TODO 自动生成的 catch 块
				e.printStackTrace();
			}
		if(connection!=null)
			try {
				connection.close();
			} catch (SQLException e) {
				// TODO 自动生成的 catch 块
				e.printStackTrace();
			}
		
		
	}

}

JdbcTest.java

package jdbc02;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class jdbcTest {	
	
	public static void main(String[] args) {
		//mySelect();
		//myInsert("橘右京","111");
		//myDelete(7);
		myUpdate(3, "李白", "123");
	}
	

	public static void mySelect() {
		Connection connection=null;
		Statement statement=null;
		ResultSet resultSet=null;
		
		try {
			connection=jdbcUtils.getconnection();
			statement=connection.createStatement();
			String sql="select * from user";
			resultSet=statement.executeQuery(sql);
			
			while(resultSet.next()) {
				System.out.println(resultSet.getInt("id")+"	"+resultSet.getString("username")+"	"
						+resultSet.getString("password"));
			}
		} catch (Exception e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		}finally {
			jdbcUtils.close(resultSet, statement, connection);
			
		}
	}
	
	public static void myInsert(String username,String password) {
		Connection connection=null;
		PreparedStatement preparedStatement=null;
		ResultSet resultSet=null;
		
		try {
			connection=jdbcUtils.getconnection();
			String sql="insert into user(username,password) values (?,?)";
			preparedStatement=connection.prepareStatement(sql);
			preparedStatement.setString(1, username);
			preparedStatement.setString(2, password);
			int result=preparedStatement.executeUpdate();
			if (result>0) {
				System.out.println("插入成功！");
			}else {
				System.out.println("插入失败！");
			}
			
		} catch (SQLException e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		}finally {
			jdbcUtils.close(resultSet, preparedStatement, connection);
		}
		
	}

	public static void myDelete(int id) {
		Connection connection=null;
		PreparedStatement preparedStatement=null;
		ResultSet resultSet=null;
		
		try {
			connection=jdbcUtils.getconnection();
			String sql="delete from user where id=?";
			preparedStatement=connection.prepareStatement(sql);
			preparedStatement.setInt(1, id);
			int result=preparedStatement.executeUpdate();
			if(result>0) {
				System.out.println("删除成功！");
			}else {
				System.out.println("删除失败！");
			}
			
		} catch (SQLException e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		}finally {
			jdbcUtils.close(resultSet, preparedStatement, connection);
		}
	}
	
	public static void myUpdate(int id,String username,String password) {
		Connection connection=null;
		PreparedStatement preparedStatement=null;
		ResultSet resultSet=null;
		
		connection=jdbcUtils.getconnection();
		String sql="update user set username=?, password=? where id=?";
		try {
			preparedStatement=connection.prepareStatement(sql);
			
			preparedStatement.setString(1, username);
			preparedStatement.setString(2, password);
			preparedStatement.setInt(3, id);
			
			int result=preparedStatement.executeUpdate();
			if(result>0) {
				System.out.println("修改成功 ");
			}else {
				System.out.println("修改失败");
			}
		} catch (Exception e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		}finally {
			jdbcUtils.close(resultSet, preparedStatement, connection);
		}

	}
}