java 工具类 (DBUtil)简介

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本文链接： https://blog.csdn.net/weixin_45104211/article/details/99592805

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;

public class DBUtil {
	static {
		try {
			Class.forName("com.mysql.jdbc.Driver");
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
	}

	static PropertiesUntil properties =new PropertiesUntil();
	
	/**
	 * 获取连接
	 * 
	 * @author SY
	 */
	private static Connection con() {
		try {
			String url=properties.getValue("jdbc.url");
			String userName=properties.getValue("jdbc.userName");
			String password=properties.getValue("jdbc.password");
			return DriverManager.getConnection(url, userName, password);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}
	/**
	 * 批量注册
	 * 
	 * @author SY
	 */
	public static boolean betch (String sqls,Object[] ...param) {
			Connection connection=null;
			PreparedStatement preparedStatement=null;
			try {
				connection=con();
				connection.setAutoCommit(false);
				preparedStatement=connection.prepareStatement(sqls);
				for(int i=0;i<param.length;i++) {
					for(int j=1;j<=param[i].length;j++) {
						preparedStatement.setObject(j, param[i][j-1]);
					}
					preparedStatement.addBatch();
				}
				preparedStatement.executeBatch();
				connection.commit();
				return true;
			} catch (Exception e) {
				e.printStackTrace();
				if(connection!=null) {
					try {
						connection.rollback();
					} catch (SQLException e1) {
						e1.printStackTrace();
					}
				}
			}finally {
				close(preparedStatement,connection);
			}
			return false;
	}
	
	/**
	 * 批量处理
	 * 
	 * @author SY
	 */
	public static boolean betch (String ...sqls) {
			Connection connection=null;
			Statement statement=null;
			try {
				connection=con();
				connection.setAutoCommit(false);
				statement =connection.createStatement();
				for (String sql : sqls) {
					statement.addBatch(sql);
				}
				statement.executeBatch();//其中有一个失败就不行，会抛出错误
				connection.commit();
				return true;
			} catch (Exception e) {
				e.printStackTrace();
				if(connection!=null) {
					try {
						connection.rollback();
					} catch (SQLException e1) {
						e1.printStackTrace();
					}
				}
			}finally {
				close(statement,connection);
			}
			return false;
	}
	
	/**
	 * 检查是否存在
	 * 
	 * @author SY
	 */
	public static boolean exist(String sql,String...param) {
		class RowMapper implements IRowMapper{
			boolean flag;
			@Override
			public void rowMapper(ResultSet resultSet) {
				try {
					flag=resultSet.next();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
		}
		RowMapper iRowMapper =new RowMapper();
		select(sql,iRowMapper,param);
		return iRowMapper.flag;
	}
	
	/**
	 * 查询数据
	 * 
	 * @author SY
	 */
	public static void select(String sql, IRowMapper iRowMapper) {
		Statement statement=null;
		Connection connection=null;
		ResultSet resultSet=null;
		try {
			connection=con();
			statement = connection.createStatement();
			resultSet =statement.executeQuery(sql);
			iRowMapper.rowMapper(resultSet);
		}catch(Exception e){
			e.printStackTrace();
		}finally {
			close(resultSet, statement, connection);
		}
	}
	
	/**
	 * 查询数据
	 * 
	 * @author SY
	 */
	public static void select(String sql,IRowMapper map,String ...mapper ) {
		Connection connection=null;
		ResultSet resultSet=null;
		PreparedStatement preparedStatement=null;
		try {
			connection=con();
			preparedStatement=connection.prepareStatement(sql);
			for(int i=1;i<=mapper.length;i++) {
				preparedStatement.setObject(i, mapper[i-1]);
			}
			resultSet=preparedStatement.executeQuery();
			map.rowMapper(resultSet);
		}catch(Exception e){
			e.printStackTrace();
		}finally {
			close(resultSet, preparedStatement, connection);
		}
	}
	
	/**
	 * 修改数据
	 * 
	 * @author SY
	 */
	public static boolean apply(String information) {
		Statement statement=null;
		Connection connection=null;
		try {
			connection=con();
			statement = connection.createStatement();
			int result=statement.executeUpdate(information);
			return result>0;
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			close(statement, connection);
		}
		return false;
	}
	
	/**
	 * 修改数据
	 * 
	 * @author SY
	 */
	public static boolean apply(String sql,String ...param) {
		Connection connection=null;
		PreparedStatement preparedStatement=null;
		try {
			connection=con();
			preparedStatement =connection.prepareStatement(sql);
			for (int i = 1; i <= param.length; i++) {
				preparedStatement.setObject(i, param[i-1]);
			}
			int result =preparedStatement.executeUpdate();
			return result >0;
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			close(preparedStatement, connection);
		}
		return false;
	}
	/**
	 * 释放资源
	 * 
	 * @author SY
	 */
	private static void close(Statement statement,Connection connection) {
		if (statement!=null) {
			try {
				statement.close();
			} catch (SQLException e) {
				e.printStackTrace();
			} 
		}
		if (connection!=null) {
			try {
				connection.close();
			} catch (SQLException e) {
				e.printStackTrace();
			} 
		}
	}
	
	/**
	 * 释放资源
	 * 
	 * @author SY
	 */
	private static void close(ResultSet resultSet,Statement statement,Connection connection) {
		if (resultSet!=null) {
			try {
				resultSet.close();
			} catch (SQLException e) {
				e.printStackTrace();
			} 
		}
		close(statement,connection);
	}
}