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Android Studio 实现实现学生信息的增删改查 -源代码 四（Servlet + 连接MySql数据库）

2021-05-20 11:34 201人阅读  评论(0)
Android Studio 实现登录注册-源代码 （连接MySql数据库）
Android Studio 实现登录注册-源代码 二（Servlet + 连接MySql数据库）
[Android Studio 实现登录注册-源代码 三（Servlet + 连接MySql数据库）实现学生信息的查询 （JSON通信）]
Android Studio 实现实现学生信息的增删改查 -源代码 四（Servlet + 连接MySql数据库）

一、完善学生信息显示

1、修改和删除的按钮在student_list.xml当中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="10dp"
    >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:layout_weight="1"
            android:text="id" />

        <TextView
            android:id="@+id/name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:layout_weight="1"
            android:text="姓名" />

        <TextView
            android:id="@+id/age"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:layout_weight="1"
            android:text="年龄" />

        <TextView
            android:id="@+id/address"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:layout_weight="1"
            android:text="地址" />

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="10dp"
            android:layout_weight="1"
            android:layout_gravity="right"
            android:orientation="horizontal">


            <Button
                android:id="@+id/button"
                android:layout_width="70dp"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:layout_gravity="right"
                android:layout_weight="1"
                android:textSize="15sp"
                android:text="修改" />

            <Button
                android:id="@+id/button4"
                android:layout_width="70dp"
                android:layout_height="wrap_content"
                android:layout_gravity="right"
                android:layout_weight="1"
                android:textSize="15sp"
                android:text="删除" />
        </LinearLayout>


    </LinearLayout>

</LinearLayout>

2、添加表头的xml，创建list_header.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="10dp"
    >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:layout_weight="1"
            android:text="id" />

        <TextView
            android:id="@+id/name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:layout_weight="1"
            android:text="姓名" />

        <TextView
            android:id="@+id/age"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:layout_weight="1"
            android:text="年龄" />

        <TextView
            android:id="@+id/address"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:layout_weight="1"
            android:text="地址" />

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="10dp"
            android:layout_weight="1"
            android:layout_gravity="right"
            android:orientation="horizontal">


            <TextView
                android:id="@+id/button"
                android:layout_width="70dp"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:layout_gravity="right"
                android:layout_weight="1"
                android:textSize="15sp"
                android:text="修改" />

            <TextView
                android:id="@+id/button4"
                android:layout_width="70dp"
                android:layout_height="wrap_content"
                android:layout_gravity="right"
                android:layout_weight="1"
                android:textSize="15sp"
                android:text="删除" />
        </LinearLayout>


    </LinearLayout>

</LinearLayout>

3、在adapter当中动态加载表头

  final LayoutInflater inflater = LayoutInflater.from(getApplicationContext());
                View headView = inflater.inflate(R.layout.list_header, null);

                if(stuList.getHeaderViewsCount()==0)
                {
   
                    stuList.addHeaderView(headView);
                }

二、实现修改学生信息的操作

（一）安卓端

1、创建显示学生信息的页面



<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".StudentUpdate">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        tools:layout_editor_absoluteX="219dp"
        tools:layout_editor_absoluteY="207dp"
        android:padding="50dp"

        >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">


            <TextView
                android:id="@+id/textView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:textSize="15sp"
                android:text="ID:" />

            <TextView
                android:id="@+id/id"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:ems="10"
                />
        </LinearLayout>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">


            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:textSize="15sp"
                android:text="昵称:" />

            <EditText
                android:id="@+id/name"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:ems="10"
                android:inputType="textPersonName"
                />
        </LinearLayout>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">


            <TextView
                android:id="@+id/textView2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:textSize="15sp"
                android:text="年龄:"

                />

            <EditText
                android:id="@+id/age"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:ems="10"
               
                />
        </LinearLayout>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">


            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"

                android:textSize="15sp"
                android:text="地址:"

                />

            <EditText
                android:id="@+id/address"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:ems="10"
                android:inputType="phone"
                />
        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">



        </LinearLayout>

        <Button
            android:layout_marginTop="50dp"
            android:id="@+id/button2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="提交"
            android:onClick="updatestudent"
            />

        <Button
            android:id="@+id/button3"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="重置" />
    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

2、在student_list.xml页面上的按钮上添加onClick

3、完善Student_List当中的update方法


  public void update(View view){
   

        LinearLayout linearLayout =  (LinearLayout)(view.getParent().getParent());

        TextView idEd = linearLayout.findViewById(R.id.id);
        TextView nameEd =  linearLayout.findViewById(R.id.name);
        TextView ageEd = linearLayout.findViewById(R.id.age);
        TextView addressEd = linearLayout.findViewById(R.id.address);

        Intent intent=new Intent();
        intent.putExtra("id", idEd.getText().toString());
        intent.putExtra("name", nameEd.getText().toString());
        intent.putExtra("age", ageEd.getText().toString());
        intent.putExtra("address", addressEd.getText().toString());
        intent.setClass(this, StudentUpdate.class);
        startActivity(intent );


        Toast.makeText(getApplicationContext(),"修改",Toast.LENGTH_LONG).show();

    }

4、StudentUpdate当中获取对应Intent 对象当中的值并放入到页面当中的修改框当中

 @Override
    protected void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_student_update);

        Intent intent = getIntent();

        String id =    intent.getStringExtra("id");
        String name =  intent.getStringExtra("name");
        String age = intent.getStringExtra("age");
        String address = intent.getStringExtra("address");


        TextView idtv = findViewById(R.id.id);
        EditText nameet = findViewById(R.id.name);
        EditText ageet = findViewById(R.id.age);
        EditText addresset = findViewById(R.id.address);

        idtv.setText(id);
        nameet.setText(name);
        ageet.setText(age);
        addresset.setText(address);


    }

运行测试


（二）web端

1、创建更新学生信息的dao


	 public boolean update(Student stu){
   

		 String sql="update student set name=?,age=?,address=? where id=?";
	        Connection  con = JDBCUtils.getConn();

	        try {
   
	            PreparedStatement pst=con.prepareStatement(sql);

	            pst.setString(1,stu.getName());
	            pst.setInt(2,stu.getAge());
	            pst.setString(3,stu.getAddress() );
	            pst.setInt(4,stu.getId()   );

	            int value = pst.executeUpdate();

	            if(value>0){
   
	                return true;
	            }


	        } catch (SQLException throwables) {
   
	            throwables.printStackTrace();
	        }finally {
   
	            JDBCUtils.close(con);
	        }
	        return false;
	    }

2、创建对应更新学生信息的Servlet




完善StudentUpdateServlet

	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
   
		
		System.out.println("-----------------");
		request.setCharacterEncoding("utf-8");
		response.setCharacterEncoding("UTF-8");
		int id = Integer.parseInt(request.getParameter("id"));
		String name = request.getParameter("name");
		int age =  Integer.parseInt(request.getParameter("age"));
		String address =  request.getParameter("address");
		
		
		Student student = new Student();

		student.setId(id);
		student.setName(name);
		student.setAge(age);
		student.setAddress(address);

        String msg = "";
        StudentDao studentDao = new StudentDao();
            
        boolean flag = studentDao.update(student);
        
        if(flag){
   
            msg = "成功";
        }else{
   
        	msg = "失败";
        }
	   
        PrintWriter out = response.getWriter();
		out.println(msg);
		out.flush();
		out.close();

		
	}

（三）安卓端

1、在StudentUpdate当中创建updatestudent实现向studentUpdateServlet发送更新信息的请求

package com.example.application01;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import com.example.application01.utils.PostUtil;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

public class StudentUpdate extends AppCompatActivity {
   

    @Override
    protected void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_student_update);

        Intent intent = getIntent();

        String id =    intent.getStringExtra("id");
        String name =  intent.getStringExtra("name");
        String age = intent.getStringExtra("age");
        String address = intent.getStringExtra("address");


        TextView idtv = findViewById(R.id.id);
        EditText nameet = findViewById(R.id.name);
        EditText ageet = findViewById(R.id.age);
        EditText addresset = findViewById(R.id.address);

        idtv.setText(id);
        nameet.setText(name);
        ageet.setText(age);
        addresset.setText(address);

    }


    public void updatestudent(View view){
   


        TextView idtv = findViewById(R.id.id);
        EditText nameet = findViewById(R.id.name);
        EditText ageet = findViewById(R.id.age);
        EditText addresset = findViewById(R.id.address);

        String id =  idtv.getText().toString();
        String name =   nameet.getText().toString();
        String age =  ageet.getText().toString();
        String address = addresset.getText().toString();


        new Thread(){
   
            @Override
            public void run() {
   

                String data="";
                try {
   
                    data = "&id="+ URLEncoder.encode(id, "UTF-8")+
                            "&name="+ URLEncoder.encode(name, "UTF-8")+
                            "&age="+ URLEncoder.encode(age, "UTF-8")+
                            "&address="+ URLEncoder.encode(address, "UTF-8");
                } catch (UnsupportedEncodingException e) {
   
                    e.printStackTrace();
                }

                String request = PostUtil.Post("studentUpdateServlet",data);

                int msg = 0;
                if(request.equals("成功")){
   
                    msg = 1;
                }


                hand.sendEmptyMessage(msg);

            }
        }.start();


    }
    Handler hand=new Handler(){
   
        @Override
        public void handleMessage(Message msg) {
   

            if(msg.what == 1)
            {
   
                startActivity(new Intent( getApplicationContext(),  Student_List.class ) );
                //startActivity(new Intent( getApplicationContext(),  StuInfoActivity.class ) );
            }
            else
            {
   
                Toast.makeText(getApplicationContext(),"更新失败",Toast.LENGTH_LONG).show();
            }
        }

    };
}

2、运行测试



Android Studio 实现登录注册-源代码 （连接MySql数据库）
Android Studio 实现登录注册-源代码 二（Servlet + 连接MySql数据库）
[Android Studio 实现登录注册-源代码 三（Servlet + 连接MySql数据库）实现学生信息的查询 （JSON通信）]
Android Studio 实现实现学生信息的增删改查 -源代码 四（Servlet + 连接MySql数据库）

转载：https://blog.csdn.net/qq_44757034/article/details/116993494
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