2020年10月27日Java学习日记
要求实现一个添加界面,添加任意课程,指定教室和老师。并实现在MYSQL的表中添加成功
CourseDao.java
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package dao; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import DBUtil.DBUtil; import domain.Course; public class CourseDao { /** * 添加 * @param course * @return */ public boolean add(Course course) { String sql = "insert into kecheng(name, teacher, classroom) values('" + course.getName() + "','" + course.getTeacher() + "','" + course.getClassroom() + "')" ; Connection conn = DBUtil.getConn(); Statement state = null ; boolean f = false ; int a = 0 ; try { state = conn.createStatement(); state.executeUpdate(sql); } catch (Exception e) { e.printStackTrace(); } finally { DBUtil.close(state, conn); } if (a > 0 ) { f = true ; } return f; } } |
DBUtil.java
package DBUtil; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class DBUtil { public static String db_url = "jdbc:mysql://localhost:3306/test?serverTimezone=GMT%2B8&useSSL=false" ; public static String db_user = "root" ; public static String db_pass = "liutianwen0613" ; public static Connection getConn () { Connection conn = null ; try { Class.forName( "com.mysql.jdbc.Driver" ); conn = DriverManager.getConnection(db_url, db_user, db_pass); } catch (Exception e) { e.printStackTrace(); } return conn; } //end getConn 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(); } } } public static void main(String[] args) throws SQLException { Connection conn = getConn(); PreparedStatement pstmt = null ; ResultSet rs = null ; String sql = "select * from kecheng" ; pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); if (rs.next()){ System.out.println( "连接成功" ); } else { System.out.println( "连接失败" ); } } } |
LTW.jsp
package DBUtil; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class DBUtil { public static String db_url = "jdbc:mysql://localhost:3306/test?serverTimezone=GMT%2B8&useSSL=false" ; public static String db_user = "root" ; public static String db_pass = "liutianwen0613" ; public static Connection getConn () { Connection conn = null ; try { Class.forName( "com.mysql.jdbc.Driver" ); conn = DriverManager.getConnection(db_url, db_user, db_pass); } catch (Exception e) { e.printStackTrace(); } return conn; } //end getConn 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(); } } } public static void main(String[] args) throws SQLException { Connection conn = getConn(); PreparedStatement pstmt = null ; ResultSet rs = null ; String sql = "select * from kecheng" ; pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); if (rs.next()){ System.out.println( "连接成功" ); } else { System.out.println( "连接失败" ); } } } |
Course.java
package domain; public class Course { private String name; private String teacher; private String classroom; public String getName() { return name; } public void setName(String name) { this .name = name; } public String getTeacher() { return teacher; } public void setTeacher(String teacher) { this .teacher = teacher; } public String getClassroom() { return classroom; } public void setClassroom(String classroom) { this .classroom = classroom; } public Course() {} public Course(String name, String teacher, String classroom) { this .name = name; this .teacher = teacher; this .classroom = classroom; } } |