今日总结

今天复习了昨天学到的Javaweb的删除更改查找三大步骤，并且进行了相应的训练。对于增删改查有了更深层的理解。

package entity;
 
public class Subject {
private int subjectID;
private String subjectTitle;
private String subjectOptionA;
private String subjectOptionB;
private String subjectOptionC;
private String subjectOptionD;
private String subjectAnswer;
private String subjectParse;
 
 
public int getSubjectID() {
    return subjectID;
}
public void setSubjectID(int subjectID) {
    this.subjectID = subjectID;
}
public String getSubjectTitle() {
    return subjectTitle;
}
public void setSubjectTitle(String subjectTitle) {
    this.subjectTitle = subjectTitle;
}
public String getSubjectOptionA() {
    return subjectOptionA;
}
public void setSubjectOptionA(String subjectOptionA) {
    this.subjectOptionA = subjectOptionA;
}
public String getSubjectOptionB() {
    return subjectOptionB;
}
public void setSubjectOptionB(String subjectOptionB) {
    this.subjectOptionB = subjectOptionB;
}
public String getSubjectOptionC() {
    return subjectOptionC;
}
public void setSubjectOptionC(String subjectOptionC) {
    this.subjectOptionC = subjectOptionC;
}
public String getSubjectOptionD() {
    return subjectOptionD;
}
public void setSubjectOptionD(String subjectOptionD) {
    this.subjectOptionD = subjectOptionD;
}
public String getSubjectAnswer() {
    return subjectAnswer;
}
public void setSubjectAnswer(String subjectAnswer) {
    this.subjectAnswer = subjectAnswer;
}
public String getSubjectParse() {
    return subjectParse;
}
public void setSubjectParse(String subjectParse) {
    this.subjectParse = subjectParse;
}
 
 
 
 
}

Subject

package dao;
 
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
 
import com.mysql.jdbc.Connection;
 
import entity.Subject;
 
public class SubjectDaoImpl implements SubjectDao {
    
    Connection conn = (Connection) DBConn.getConn();
 
    
    @Override
    public boolean add(Subject subject) {
        boolean flag = false;
        
        
        try {
            String sql="insert tb_subject values('"+subject.getSubjectID()+"','"
                     +subject.getSubjectTitle()+"','"
                     +subject.getSubjectOptionA()+"','"
                     +subject.getSubjectOptionB()+"','"
                     +subject.getSubjectOptionC()+"','"
                     +subject.getSubjectOptionD()+"','"
                     +subject.getSubjectAnswer()+"','"
                     +subject.getSubjectParse()+"')";
            PreparedStatement pstmt = conn.prepareStatement(sql);
            int i = pstmt.executeUpdate();
            pstmt.close();
            conn.close();
            if(i>0) {
                flag = true;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return flag;
    }
 
 
    @Override
    public List<Subject> selectall() {
        List<Subject> list = new ArrayList<Subject>();
        try {
            String sql = "select * from tb_subject";
            PreparedStatement pstmt = conn.prepareStatement(sql);
            ResultSet rs = pstmt.executeQuery();
            while(rs.next()) {
                Subject subject = new Subject();
                subject.setSubjectID(rs.getInt("subjectID"));
                subject.setSubjectTitle(rs.getString("subjectTitle"));
                subject.setSubjectOptionA(rs.getString("subjectOptionA"));
                subject.setSubjectOptionB(rs.getString("subjectOptionB"));
                subject.setSubjectOptionC(rs.getString("subjectOptionC"));
                subject.setSubjectOptionD(rs.getString("subjectOptionD"));
                subject.setSubjectAnswer(rs.getString("subjectAnswer"));
                subject.setSubjectParse(rs.getString("subjectParse"));
                list.add(subject);
            }
            rs.close();
            pstmt.close();
            conn.close();
            
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return list;
    }
    
    @Override
    public List<Subject> selectByID(String subjectID) {
        List<Subject> list = new ArrayList<Subject>();
        try {
            String sql = "select * from tb_subject where subjectID=?";
            PreparedStatement pstmt = conn.prepareStatement(sql);
            pstmt.setString(1,subjectID );
            ResultSet rs = pstmt.executeQuery();
            while(rs.next()) {
                Subject subject = new Subject();
                subject.setSubjectID(rs.getInt("subjectID"));
                subject.setSubjectTitle(rs.getString("subjectTitle"));
                subject.setSubjectOptionA(rs.getString("subjectOptionA"));
                subject.setSubjectOptionB(rs.getString("subjectOptionB"));
                subject.setSubjectOptionC(rs.getString("subjectOptionC"));
                subject.setSubjectOptionD(rs.getString("subjectOptionD"));
                subject.setSubjectAnswer(rs.getString("subjectAnswer"));
                subject.setSubjectParse(rs.getString("subjectParse"));
                list.add(subject);
            }
            rs.close();
            pstmt.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
        return list;
    }
 
    @Override
    public boolean update( String subjectTitle,
            String subjectOptionA, String subjectOptionB,
            String subjectOptionC, String subjectOptionD, String subjectAnswer,
            String subjectParse) {
        boolean flag = false;
        try {
            String sql = "update tb_subject set subjectOptionA = '"+subjectOptionA+"',subjectOptionB = '"+subjectOptionB+"',subjectOptionC = '"+subjectOptionC+
                    "',subjectOptionD = '"+subjectOptionD+"',subjectAnswer = '"+subjectAnswer+"',subjectParse = '"+subjectParse+"' where subjectTitle = '"+subjectTitle+"'";
            
            PreparedStatement pstmt = conn.prepareStatement(sql);
            int i = pstmt.executeUpdate();
            pstmt.close();
            conn.close();
            if(i>0)flag = true;
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return flag;
    }
 
    @Override
    public boolean delete(int subjectID) {
        boolean flag = false;
        
        try {
            String sql = "delete from tb_subject where subjectID = '"+subjectID+"'";
            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;
    }
 
 
    
 
 
 
}

StudentDao

<div id="addSubjectForm" align="center"><!--录入试题表单-->
                <form action="SubjectAddServlet" method="post">
                <table border="0" cellspacing="10" cellpadding="0">
                  <tr>
                    <td colspan="2"><FONT color="red"><s:actionerror/></FONT></td>
                  </tr>
                  <tr>
                    <td>试题题目:</td>
                    <td><input type="text" name="subjectTitle" size="80" ></td>
                  </tr>
                  <tr>
                    <td>选项A:</td>
                    <td><input type="text" name="subjectOptionA" size="20" ></td>
                  </tr>
                   <tr>
                    <td>选项B:</td>
                    <td><input type="text" name="subjectOptionB" size="20" ></td>
                  </tr>
                   <tr>
                    <td>选项C:</td>
                    <td><input type="text" name="subjectOptionC" size="20" ></td>
                  </tr>
                   <tr>
                    <td>选项D:</td>
                    <td><input type="text" name="subjectOptionD" size="20" ></td>
                  </tr>
                   <tr>
                    <td>答案:</td>
                    <td>
                        <input name="subjectAnswer" type="radio" value="A" checked>A
                        <input name="subjectAnswer" type="radio" value="B">B
                        <input name="subjectAnswer" type="radio" value="C">C
                        <input name="subjectAnswer" type="radio" value="D">D
                    </td>
                  </tr>
                  <tr>
                    <td valign="top">试题解析:</td>
                    <td>
                        <textarea name="subjectParse" cols="76" rows="10"></textarea>
                    </td>
                  </tr>
                  <tr>
                      <td colspan="2"><div align="center">
                        <input type="submit" value="录入">                        
                        <input type="reset" value="重置">
                    </div>
                </td>
                  </tr>
            </table>                                                                                                
            </form>

add

package action;
 
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import dao.SubjectDao;
import dao.SubjectDaoImpl;
import entity.Subject;
 
public class SubjectDeleteServlet extends HttpServlet {
 
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request, response);
    }
 
    
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        
        String subjejctID = (String) request.getParameter("subjectID");
        int userSubjectID = Integer.parseInt(subjejctID);
        
        SubjectDao sd = new SubjectDaoImpl();
        sd.delete(userSubjectID);
    }
 
}

delete

<div id="manageSubject" align="center"><!--删除试题-->
            <table width="95%" cellspacing="10">
                  <tr align="center">
                    <td>试题编号</td>
                    <td>试题标题</td>
                    <td>正确答案</td>
                    <td>查看试题</td>
                         </tr>
                  
                       
                      
                    <c:forEach var="s" items="${list }">
                        <tr align="center">
                            <td>${s.subjectID }</td>
                            <td align="left">${s.subjectTitle }</td>
                            <td>${s.subjectAnswer }</td>
                            <td><a href="SubjectShowServlet?subjectID=${s.subjectID }">查看</a></td>
                            <td><a href="SubjectDeleteServlet?subjectID=${s.subjectID }">删除</a></td>
                        </tr>
                    </c:forEach>
                 
            </table>
        </div>

update

<div id="updateSubjectForm" align="center"><!--更新试题表单-->
                <form action="SubjectUpdateServlet" method="post">
                <table border="0" cellspacing="10" cellpadding="0">
                    <tr>
                        <td colspan="2"><s:actionmessage/></td>
                    </tr>
                  <tr>
                    <td>试题题目:</td>
                    <td>
                        <input name="subjectID" type="hidden" >
                        <input name="subjectTitle" type="text" size="80"  >
                    </td>
                  </tr>
                  <tr>
                    <td>选项A:</td>
                    <td><input type="text" name="subjectOptionA" size="20" ></td>
                  </tr>
                   <tr>
                    <td>选项B:</td>
                    <td><input type="text" name="subjectOptionB" size="20" ></td>
                  </tr>
                   <tr>
                    <td>选项C:</td>
                    <td><input type="text" name="subjectOptionC" size="20" ></td>
                  </tr>
                   <tr>
                    <td>选项D:</td>
                    <td><input type="text" name="subjectOptionD" size="20" ></td>
                  </tr>
                   <tr>
                    <td>答案:</td>
                    <td>
                <input type="text" name="subjectAnswer" size="20" value="">
                    </td>
                  </tr>
                  <tr>
                    <td valign="top">答案解析:</td>
                    <td>
                        <textarea name="subjectParse" cols="76" rows="10" ></textarea>
                    </td>
                  </tr>
                  <tr>
                      <td colspan="2"><div align="center">
                        <input type="submit" value="更新">                        
                        <input type="reset" value="重置">
                    </div>
                </td>
                  </tr>
            </table>
            </form>    
            </div>

request

posted @ 2023-02-26 19:55 北·岛阅读(16) 评论(0) 收藏举报

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