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）
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）
源代码下载：
https://download.csdn.net/download/qq_44757034/19685905
一、完善学生信息显示
1、修改和删除的按钮在student_list.xml当中
2、添加表头的xml，创建list_header.xml
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
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）