2023.4.2——补充（对于2023.3.24——课后作业）
地铁查询系统（Android）
1.设计思想：
1）线路查询：这个比较好实现，利用sql语句，根据输入的线路号，查询站点名称并输出到web上；
2）站点查询：这个比较好实现，利用sql语句，根据输入的站点名称，查询线路号并输出到web上；
3）起点—终点查询：利用Dijkstra算法找到最短路径，输入起始站和终点站后，计数最短路径经过的站点数，若中间有换线路，记录线路并输出。
2.源程序代码：
1）Check1Activity.java
查看代码
package com.example.underground;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.os.StrictMode;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.sql.SQLException;
public class Check1Activity extends AppCompatActivity implements View.OnClickListener {
private DBUtil util;
private EditText etCheck1;
private Button btnCheck1;
private TextView tvCheck1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_check1);
setTitle("线路查询");
util = new DBUtil();
//忘了干啥的了
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
etCheck1 = findViewById(R.id.et_check1);
tvCheck1 = findViewById(R.id.tv_check1);
btnCheck1 = findViewById(R.id.btn_check1);
btnCheck1.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btn_check1:
String text = etCheck1.getText().toString().trim();
String data= "";
if(TextUtils.isEmpty(text)){
data="输入为空！";
}
else {
try {
data = util.getCheck1(text);
} catch (SQLException e) {
data = "线路不存在！";
}
if(data.equals("此地铁线路途径站点如下：\n")){
data="线路不存在！";
}
}
tvCheck1.setText(data);
break;
}
}
}2）Check2Activity.java
查看代码
package com.example.underground;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.os.StrictMode;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.sql.SQLException;
public class Check2Activity extends AppCompatActivity implements View.OnClickListener {
private DBUtil util;
private EditText etCheck2;
private Button btnCheck2;
private TextView tvCheck2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_check2);
setTitle("站点查询");
util = new DBUtil();
//忘了干啥的了
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
etCheck2 = findViewById(R.id.et_check2);
tvCheck2 = findViewById(R.id.tv_check2);
btnCheck2 = findViewById(R.id.btn_check2);
btnCheck2.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btn_check2:
String text = etCheck2.getText().toString().trim();
String data= "";
if(TextUtils.isEmpty(text)){
data="输入为空！";
}
else {
try {
data = util.getCheck2(text);
} catch (SQLException e) {
data = "站点不存在！";
}
if(data.equals("途径该站点的线路如下：\n")){
data="站点不存在！";
}
}
tvCheck2.setText(data);
break;
}
}
}3）Check3Activity.java
查看代码
package com.example.underground;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.os.StrictMode;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.sql.SQLException;
public class Check3Activity extends AppCompatActivity implements View.OnClickListener {
private DBUtil util;
private EditText etCheck31;
private EditText etCheck32;
private Button btnCheck3;
private TextView tvCheck3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_check3);
setTitle("起点—终点查询");
util = new DBUtil();
//忘了干啥的了
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
etCheck31 = findViewById(R.id.et_check31);
etCheck32 = findViewById(R.id.et_check32);
tvCheck3 = findViewById(R.id.tv_check3);
btnCheck3 = findViewById(R.id.btn_check3);
btnCheck3.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btn_check3:
String text1 = etCheck31.getText().toString().trim();
String text2 = etCheck32.getText().toString().trim();
String data= "";
if(TextUtils.isEmpty(text1)||TextUtils.isEmpty(text2)){
data="输入为空！";
}
else {
try {
data = util.getCheck3(text1,text2);
} catch (SQLException e) {
data = "两站点间不能通行！";
}
if(data.equals("")){
data="两站点间不能通行！";
}
}
tvCheck3.setText(data);
break;
}
}
}4）DBUtil.java
查看代码
package com.example.underground;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
public class DBUtil {
//连接数据库
public Connection getConnection() {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
throw new RuntimeException(e);
}
Connection con = null;
try {
con = DriverManager.getConnection("jdbc:mysql://192.168.200.144:3306/test1?useUnicode=true&characterEncoding=utf8", "tong", "123456");
} catch (SQLException e) {
throw new RuntimeException(e);
}
return con;
}
//check1
public String getCheck1(String text) throws SQLException {
String data="此地铁线路途径站点如下："+"\n";
Connection connection = getConnection();
PreparedStatement preparedStatement = null;
String sql = "select distinct station_name from bj_subway where line_name like ?";
preparedStatement=connection.prepareStatement(sql);
preparedStatement.setString(1, text+"%");
ResultSet rs=preparedStatement.executeQuery();
while(rs.next()){
data+=rs.getString("station_name");
data+="\n";
}
return data;
}
//check2
public String getCheck2(String text) throws SQLException {
String data="途径该站点的线路如下："+"\n";
Connection connection = getConnection();
PreparedStatement preparedStatement = null;
String sql = "select distinct line_name from bj_subway where station_name = ?";
preparedStatement=connection.prepareStatement(sql);
preparedStatement.setString(1, text);
ResultSet rs=preparedStatement.executeQuery();
while(rs.next()){
data+=rs.getString("line_name");
data+="\n";
}
return data;
}
//check3
public String getCheck3(String text1,String text2) throws SQLException {
String data="";
Connection connection = getConnection();
PreparedStatement preparedStatement = null;
String sql = "WITH RECURSIVE transfer (start_station, stop_station, stops, path) AS ( SELECT station_name, next_station, 1, CAST(CONCAT(line_name,station_name , '\n', line_name,next_station) AS CHAR(1000)) FROM bj_subway WHERE station_name = ? UNION ALL SELECT p.start_station, e.next_station, stops + 1, CONCAT(p.path, '\n', e.line_name, e.next_station) FROM transfer p JOIN bj_subway e ON p.stop_station = e.station_name AND (INSTR(p.path, e.next_station) = 0) ) SELECT * FROM transfer WHERE stop_station = ?";
preparedStatement=connection.prepareStatement(sql);
preparedStatement.setString(1, text1);
preparedStatement.setString(2, text2);
ResultSet rs=preparedStatement.executeQuery();
while(rs.next()){
int stops=rs.getInt("stops")+1;
data=data+"共经过"+stops+"站：\n";
data+=rs.getString("path");
data+="\n";
break;
}
return data;
}
}5）MainActivity.java
查看代码
package com.example.underground;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private Button btnCheck1, btnCheck2, btnCheck3, btnCheck4;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setTitle("地铁查询系统");
btnCheck1 = findViewById(R.id.btn_check1);
btnCheck2 = findViewById(R.id.btn_check2);
btnCheck3 = findViewById(R.id.btn_check3);
btnCheck4 = findViewById(R.id.btn_check4);
btnCheck1.setOnClickListener(this);
btnCheck2.setOnClickListener(this);
btnCheck3.setOnClickListener(this);
btnCheck4.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btn_check1:
startActivity(new Intent(this,Check1Activity.class));
break;
case R.id.btn_check2:
startActivity(new Intent(this,Check2Activity.class));
break;
case R.id.btn_check3:
startActivity(new Intent(this,Check3Activity.class));
break;
case R.id.btn_check4:
Uri uri = Uri.parse("http://map.amap.com/subway/index.html");
startActivity(new Intent(Intent.ACTION_VIEW,uri));
break;
}
}
}6）activity_check1.xml
查看代码
<?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:orientation="vertical"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="30dp"
android:layout_marginTop="40dp"
android:layout_marginRight="30dp"
android:gravity="center"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="线路查询"
android:textColor="@color/black"
android:textSize="30sp" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="15dp"
android:layout_marginRight="20dp"
android:gravity="center_vertical"
android:orientation="horizontal">
<EditText
android:id="@+id/et_check1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:gravity="center_horizontal"
android:hint="请输入要查询的线路"
android:selectAllOnFocus="true"
android:inputType="text"
android:paddingLeft="10dp"
android:textSize="18sp" />
</LinearLayout>
<Button
android:id="@+id/btn_check1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="100dp"
android:layout_marginTop="10dp"
android:layout_marginRight="100dp"
android:text="线路查询"
android:textSize="30sp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="30dp"
android:layout_marginTop="10dp"
android:layout_marginRight="30dp"
android:gravity="center"
android:orientation="horizontal">
<ScrollView
android:id="@+id/sv"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<TextView
android:id="@+id/tv_check1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="null"
android:textColor="@color/black"
android:textSize="25sp" />
</ScrollView>
</LinearLayout>
</LinearLayout>7）activity_check2.xml
查看代码
<?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:orientation="vertical"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="40dp"
android:layout_marginRight="20dp"
android:gravity="center"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="站点查询"
android:textColor="@color/black"
android:textSize="30sp" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="15dp"
android:layout_marginRight="20dp"
android:gravity="center_vertical"
android:orientation="horizontal">
<EditText
android:id="@+id/et_check2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:gravity="center_horizontal"
android:hint="请输入要查询的站点"
android:inputType="text"
android:paddingLeft="10dp"
android:textSize="18sp" />
</LinearLayout>
<Button
android:id="@+id/btn_check2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="100dp"
android:layout_marginTop="10dp"
android:layout_marginRight="100dp"
android:text="站点查询"
android:textSize="30sp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="30dp"
android:layout_marginTop="10dp"
android:layout_marginRight="30dp"
android:gravity="center"
android:orientation="horizontal">
<ScrollView
android:id="@+id/sv"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<TextView
android:id="@+id/tv_check2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="null"
android:textColor="@color/black"
android:textSize="25sp" />
</ScrollView>
</LinearLayout>
</LinearLayout>8）activity_check3.xml
查看代码
<?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:orientation="vertical"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="40dp"
android:layout_marginRight="20dp"
android:gravity="center"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="起点-终点查询"
android:textColor="@color/black"
android:textSize="30sp" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="10dp"
android:layout_marginRight="20dp"
android:gravity="center_vertical"
android:orientation="vertical">
<EditText
android:id="@+id/et_check31"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:gravity="center_horizontal"
android:hint="请输入要查询的起点"
android:selectAllOnFocus="true"
android:inputType="text"
android:paddingLeft="10dp"
android:textSize="18sp" />
<EditText
android:id="@+id/et_check32"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp"
android:gravity="center_horizontal"
android:hint="请输入要查询的终点"
android:selectAllOnFocus="true"
android:inputType="text"
android:paddingLeft="10dp"
android:textSize="18sp" />
</LinearLayout>
<Button
android:id="@+id/btn_check3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="70dp"
android:layout_marginTop="10dp"
android:layout_marginRight="70dp"
android:text="起点-终点查询"
android:textSize="30sp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="30dp"
android:layout_marginTop="10dp"
android:layout_marginRight="30dp"
android:gravity="center"
android:orientation="horizontal">
<ScrollView
android:id="@+id/sv"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<TextView
android:id="@+id/tv_check3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="null"
android:textColor="@color/black"
android:textSize="25sp" />
</ScrollView>
</LinearLayout>
</LinearLayout>9）activity_main.xml
查看代码
<?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:orientation="vertical"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="40dp"
android:layout_marginRight="20dp"
android:gravity="center"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="地铁查询系统"
android:textSize="30sp"
android:textColor="@color/black" />
</LinearLayout>
<Button
android:id="@+id/btn_check1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="20dp"
android:layout_marginRight="20dp"
android:text="线路查询"
android:textSize="30sp" />
<Button
android:id="@+id/btn_check2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="20dp"
android:layout_marginRight="20dp"
android:text="站点查询"
android:textSize="30sp" />
<Button
android:id="@+id/btn_check3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="20dp"
android:layout_marginRight="20dp"
android:text="起点-终点查询"
android:textSize="30sp" />
<Button
android:id="@+id/btn_check4"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="20dp"
android:layout_marginRight="20dp"
android:text="地图"
android:textSize="30sp" />
</LinearLayout>10）AndroidManifest.xml
查看代码
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<application
android:allowBackup="true"
android:dataExtractionRules="@xml/data_extraction_rules"
android:fullBackupContent="@xml/backup_rules"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/Theme.Underground"
tools:targetApi="31">
<activity
android:name=".Check3Activity"
android:exported="false" />
<activity
android:name=".Check2Activity"
android:exported="false" />
<activity
android:name=".Check1Activity"
android:exported="false" />
<activity
android:name=".MainActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>3.运行结果截图
4.编程总结分析
这次的程序对于我们来说还是比较难的，尤其是起点——终点查询的功能，另外那些附加的功能对于我们来说就更难了。
通过此次编程，我对于数据库的使用，Android的认识，MySQL的认识更加深入。
5.时间记录日志
