论文查询系统（一）
bean.java
package Bean; public class bean { private String id; private String name; private String title; private String booktitle; private String author; private String pdf; private String date; public String getId() { return id; } public void setId(String id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAuthor() { return author; } public void setAuthor(String author) { this.author = author; } public String getPdf() { return pdf; } public void setPdf(String pdf) { this.pdf = pdf; } public String getBooktitle() { return booktitle; } public void setBooktitle(String booktitle) { this.booktitle = booktitle; } public String getDate() { return date; } public void setDate(String date) { this.date = date; } }
dao.java
package Dao; import Bean.bean; import DBUtil.dbutil; import java.sql.*; import java.util.ArrayList; import java.util.List; import java.util.ArrayList; public class dao { public List<bean> searchBytitle(String title){ List<bean> list = new ArrayList<bean>(); try { Connection conn = dbutil.getConn(); Statement state = null; String sql="select * from test1 where title REGEXP '"+title+"'"; PreparedStatement pstmt = conn.prepareStatement(sql); ResultSet rs = pstmt.executeQuery(); System.out.println("以title为搜索对象运行中"); while(rs.next()){ bean lu = new bean(); lu.setId(rs.getString("id")); lu.setAuthor(rs.getString("author")); lu.setTitle(rs.getString("title")); lu.setPdf(rs.getString("pdf")); lu.setBooktitle(rs.getString("booktitle")); lu.setDate(rs.getString("date")); list.add(lu); } rs.close(); pstmt.close(); conn.close(); }catch(SQLException e) { System.out.println("发生错误"); e.printStackTrace(); } return list; } public List<bean> search(String author,String title){ List<bean> list = new ArrayList<bean>(); try { Connection conn = dbutil.getConn(); Statement state = null; String sql = "select * from test1 where title REGEXP '"+title+"' and author REGEXP '"+author+"'"; PreparedStatement pstmt = conn.prepareStatement(sql); ResultSet rs = pstmt.executeQuery(); System.out.println("多项条件搜索运行中"); while(rs.next()){ bean lu = new bean(); lu.setId(rs.getString("id")); lu.setAuthor(rs.getString("author")); lu.setTitle(rs.getString("title")); lu.setPdf(rs.getString("pdf")); lu.setBooktitle(rs.getString("booktitle")); lu.setDate(rs.getString("date")); list.add(lu); } rs.close(); pstmt.close(); conn.close(); }catch(SQLException e) { System.out.println("发生错误"); e.printStackTrace(); } return list; } public static bean getbean(String id){ bean lu = new bean(); try { Connection conn = dbutil.getConn(); Statement state = null; String sql="select * from test1 where id=?"; PreparedStatement pstmt = conn.prepareStatement(sql); pstmt.setString(1,id); ResultSet rs = pstmt.executeQuery(); while(rs.next()){ lu.setId(rs.getString("id")); lu.setAuthor(rs.getString("author")); lu.setTitle(rs.getString("title")); lu.setPdf(rs.getString("pdf")); lu.setBooktitle(rs.getString("booktitle")); lu.setDate(rs.getString("date")); } rs.close(); pstmt.close(); conn.close(); } catch(SQLException e) { e.printStackTrace(); } return lu; } public boolean delete(String id) { boolean flag = false; Connection conn = dbutil.getConn(); Statement state = null; try { String sql = "delete from test1 where id = '"+id+"'"; PreparedStatement pstmt = conn.prepareStatement(sql); int i = pstmt.executeUpdate(); pstmt.close(); conn.close(); if(i>0) flag = true; } catch (SQLException e) { System.out.println("删除失败！"); e.printStackTrace(); } return flag; } public static void update(String title, String author, String date, String pdf, String id) { try { PreparedStatement preparedStatement = null; Connection connect = DriverManager.getConnection("jdbc:mysql://localhost:3306/py?&useSSL=false&serverTimezone=UTC", "root", "123456"); preparedStatement = connect.prepareStatement("Update test1 set title=?,author=?,date=? ,pdf=? where id=?"); preparedStatement.setString(1, title); preparedStatement.setString(2, author); preparedStatement.setString(3, date); preparedStatement.setString(4, pdf); preparedStatement.setString(5, id); preparedStatement.executeUpdate(); preparedStatement.execute(); connect.close(); } catch (SQLException e) { e.printStackTrace(); } } public static boolean add(String title, String author, String date, String pdf) { boolean flag=false; try { PreparedStatement preparedStatement=null; Connection connect = DriverManager.getConnection("jdbc:mysql://localhost:3306/py?&useSSL=false&serverTimezone=UTC","root","123456"); preparedStatement=connect.prepareStatement("insert into test1 (title,author,date,pdf) values (?,?,?,?)"); preparedStatement.setString(1,title); preparedStatement.setString(2,author); preparedStatement.setString(3,date); preparedStatement.setString(4,pdf); preparedStatement.executeUpdate(); connect.close(); preparedStatement.close(); flag=true; }catch(SQLException e){ e.printStackTrace(); } return flag; } }
dbutil.java
package DBUtil; import java.sql.*; public class dbutil { static final String JDBC_DRIVER = "com.mysql.jdbc.Driver"; //数据库驱动名 static final String url = "jdbc:mysql://localhost:3306/py";//数据库地址 static final String user = "root"; static final String password = "123456"; //连接数据库 public static Connection getConn () { Connection conn = null; try { Class.forName("com.mysql.cj.jdbc.Driver");//加载驱动 conn = DriverManager.getConnection(url, user, password); } catch (Exception e) { e.printStackTrace(); } return conn; } //关闭连接 public static void close (PreparedStatement preparedState, Connection conn) { if (preparedState != null) { try { preparedState.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } public static void close (ResultSet rs, PreparedStatement preparedState, Connection conn) { if (rs != null) { try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } } if (preparedState != null) { try { preparedState.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } /** * 关闭连接 * @param state * @param conn */ public static void close (Statement state, Connection conn) { if (state != null) { try { state.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } public static void close (ResultSet rs, Statement state, Connection conn) { if (rs != null) { try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } } if (state != null) { try { state.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } //测试是否连接成功 public static void main(String[] args) throws SQLException { Connection conn = getConn(); PreparedStatement preparedStatement = null; ResultSet rs = null; String sql ="select * from lunwen";//数据库名称 preparedStatement = conn.prepareStatement(sql); rs = preparedStatement.executeQuery(); if(rs.next()){ System.out.println("数据库不为空"); } else{ System.out.println("数据库为空"); } } }
