团队冲刺（二）

一、认领任务

经过团队讨论，我认领到的工作是：利用数据库的数据实现益食物页面的布局，以二级目录显示食物列表

二、任务完成时间估算

页面布局	2h
从数据库提取	5h

益食物页面

展示如下：

 

可以从数据库提取数据。在这里感谢团队的闫起材体同学爬取的数据

主要用的是Tomcat+mysql搭建后台。

主要的实现代码：

foods（Activity）

package com.example.myapplication5;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.view.Window;
import android.widget.ExpandableListView;
import android.widget.ImageButton;
import android.widget.SearchView;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.List;

import com.alibaba.fastjson.JSON;
import com.example.myapplication5.Shiwu;


public class foods extends AppCompatActivity {
    // 定义扩展ExpandableListView 所需要变量
    private ExpandableListView expandablelistview;
    private MyExpandAdapter myExpandAdapter;
    private ImageButton imageButton;

    // 一级名称
    private String[] groupName = new String[]{"谷薯芋、杂豆、主食", "蛋类、肉类及制品", "奶类及制品","蔬果和菌藻","坚果、大豆及制品","饮料","食用油、油脂及制品","调味品","零食、点心、冷饮","其它","菜肴"
    };
    private int[] groupPic = new int[]{R.drawable.one, R.drawable.two,
            R.drawable.three,R.drawable.four,R.drawable.five,R.drawable.six,R.drawable.seven,R.drawable.eight,R.drawable.nine,R.drawable.ten,R.drawable.eleven};
    // 二级名称
    private String[][] childName = new String[11][100];
    //二级热量
    private String[][] childReliang = new String[11][100];
    //把二级图片去掉了

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getSupportActionBar().hide();
        setContentView(R.layout.tab01_5);
        imageButton = findViewById(R.id.imageButton21);
        imageButton.setImageResource(R.drawable.back);
        imageButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                          foods.this.finish();
            }
        });
        SearchView searchView = findViewById(R.id.sv);
        //设置该SearchView默认是否自动缩小为图标
        searchView.setIconifiedByDefault(false);
        //设置该SearchView显示搜索按钮
        searchView.setSubmitButtonEnabled(true);
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            //单机搜索按钮时激发该方法
            @Override
            public boolean onQueryTextSubmit(String query) {
                if (query.equals("")) {
                    Toast.makeText(foods.this, "您输入的内容为空",
                            Toast.LENGTH_SHORT).show();
                } else {
                    //Toast//实际应用中应该在该方法内执行实际查询，此处仅使用Toast显示用户输入的查询内容
                    Toast.makeText(foods.this, "你的选择是：" + query,
                            Toast.LENGTH_SHORT).show();
                    Intent intent = new Intent(foods.this, SActivity.class);
                    intent.putExtra("key1", query);
                    startActivity(intent);

                }
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                return false;
            }


        });

        expandablelistview = findViewById(R.id.elv);

        class postTask extends AsyncTask {

            @Override
            protected Object doInBackground(Object[] params) {
                String path=params[0].toString();
                try {
                    //获取网络上get方式提交的整个路径
                    URL url=new URL(path);
                    //打开网络连接
                    HttpURLConnection conn= (HttpURLConnection) url.openConnection();
                    //设置提交方式
                    conn.setRequestMethod("POST");
                    //设置网络超时时间
                    conn.setConnectTimeout(5000);
                    conn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");//键和值是固定的
                    //设置允许对外输出数据
                    conn.setDoOutput(true);
                    //把界面上的所有数据写出去
                    if(conn.getResponseCode()==200){
                        //用io流与web后台进行数据交互
                        InputStream is=conn.getInputStream();
                        //字节流转字符流
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        //读出每一行的数据
                        String str=br.readLine();
                        //返回读出的每一行的数据
                        return str;
                    }
                } catch (MalformedURLException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                return null;
            }

            @Override
            protected void onPostExecute(Object o) {
                super.onPostExecute(o);
                //获取Android studio与web后台数据交互获得的值
                String s= (String) o;
                List<Shiwu> shopInfos = JSON.parseArray(s, Shiwu.class);
                int i=0,j=0,k=0,l=0,m=0,n=0,p=0,q=0,r=0,t=0,u=0;


                for (Shiwu shiwu : shopInfos) {

                    System.out.println(shiwu.getClasses());
                    System.out.println(shiwu.getName());
                    System.out.println(shiwu.getCalory());
                    if(shiwu.getClasses().equals("谷薯芋、杂豆、主食
" +
                            "  "))
                    {
                        childName[0][i]=shiwu.getName();
                        childReliang[0][i]=shiwu.getCalory();
                        i++;
                    }else if(shiwu.getClasses().equals("蛋类、肉类及制品
" +
                            "  ")){
                        childName[1][j]=shiwu.getName();
                        childReliang[1][j]=shiwu.getCalory();
                        j++;
                    }else if(shiwu.getClasses().equals("奶类及制品
" +
                            "  ")){
                        childName[2][k]=shiwu.getName();
                        childReliang[2][k]=shiwu.getCalory();
                        k++;
                    }else if(shiwu.getClasses().equals("蔬果和菌藻
" +
                            "  ")){
                        childName[3][l]=shiwu.getName();
                        childReliang[3][l]=shiwu.getCalory();
                        l++;
                    }else if(shiwu.getClasses().equals("坚果、大豆及制品
" +
                            "  ")){
                        childName[4][m]=shiwu.getName();
                        childReliang[4][m]=shiwu.getCalory();
                        m++;
                    }else if(shiwu.getClasses().equals("饮料
" +
                            "  ")){
                        childName[5][n]=shiwu.getName();
                        childReliang[5][n]=shiwu.getCalory();
                        n++;
                    }else if(shiwu.getClasses().equals("食用油、油脂及制品
" +
                            "  ")){
                        childName[6][p]=shiwu.getName();
                        childReliang[6][p]=shiwu.getCalory();
                        p++;
                    }else if(shiwu.getClasses().equals("调味品
" +
                            "  ")){
                        childName[7][q]=shiwu.getName();
                        childReliang[7][q]=shiwu.getCalory();
                        q++;
                    }else if(shiwu.getClasses().equals("零食、点心、冷饮
" +
                            "  ")){
                        childName[8][r]=shiwu.getName();
                        childReliang[8][r]=shiwu.getCalory();
                        r++;
                    }else if(shiwu.getClasses().equals("其它
" +
                            "  ")){
                        childName[9][t]=shiwu.getName();
                        childReliang[9][t]=shiwu.getCalory();
                        t++;
                    }else if(shiwu.getClasses().equals("菜肴
" +
                            "  ")){
                        childName[10][u]=shiwu.getName();
                        childReliang[10][u]=shiwu.getCalory();
                        u++;
                    }
                }
//                Toast.makeText(LoginActivity.this, sourceStrArray[0]+sourceStrArray[1], Toast.LENGTH_SHORT).show();
                dosome();
            }

        }
        String path="http://10.0.2.2:8080/testhttp/Show.Servlet";//这里是本地web的地址，先运行httptest的Servlet再启动，才不会闪退。而http://120.79.40.20/testhttp/
        //调用postTask,把获取到的数据与路径放入方法中，这里没有放数据。
        new postTask().execute(path);
    }
    public void dosome(){
        //传递参数
        myExpandAdapter = new MyExpandAdapter(this, groupName, childName, childReliang, groupPic);
        expandablelistview.setAdapter(myExpandAdapter);
//点击Toast
        expandablelistview.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
                Toast.makeText(getApplicationContext(),
                        groupName[groupPosition] + ":" + childName[groupPosition][childPosition] + ":" + childReliang[groupPosition][childPosition],
                        Toast.LENGTH_SHORT).show();
                return false;
            }
        });

    }
}

相应的适配器：

MyExpandAdapter

package com.example.myapplication5;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class MyExpandAdapter extends BaseExpandableListAdapter {
    private String[] groupName;
    private String[][] childName;
    private String[][] childReliang;
    private int[] groupPic;
    private int[][] childPic;

    LayoutInflater inflater;

    public MyExpandAdapter(Context context, String[] groupName, String[][] childName,String[][] childReliang, int[] groupPic) {
        this.inflater = LayoutInflater.from(context);
        this.groupName = groupName;
        this.childName = childName;
        this.childReliang = childReliang;
        this.groupPic = groupPic;
    }

    @Override
    public int getGroupCount() {
        return groupName.length;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return childName[groupPosition].length;
    }


    @Override
    public Object getGroup(int groupPosition) {
        return groupName[groupPosition];
    }

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return childName[groupPosition][childPosition];
    }


    public Object getChildReliang(int groupPosition, int childPosition) {
        return childReliang[groupPosition][childPosition];
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        convertView = inflater.inflate(R.layout.group_item, null);
        TextView textView = convertView.findViewById(R.id.textView_g);
        textView.setText(getGroup(groupPosition).toString());
        ImageView imageView = convertView.findViewById(R.id.imageView_g);
        imageView.setImageResource(groupPic[groupPosition]);
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        convertView = inflater.inflate(R.layout.child_item, null);
        TextView nickTextView = convertView.findViewById(R.id.textView_c2);
        TextView ReliangTextView = convertView.findViewById(R.id.textView_c3);
        nickTextView.setText(getChild(groupPosition, childPosition).toString());
        ReliangTextView.setText(getChildReliang(groupPosition, childPosition).toString());
//        ImageView imageView = convertView.findViewById(R.id.imageView2);
//        imageView.setImageResource(childPic[groupPosition][childPosition]);
        return convertView;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }
}

xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:background="@drawable/healthbg3">

    <!--定义自动完成的ListView-->
    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="61dp">

        <ImageButton
            android:id="@+id/imageButton21"
            android:layout_width="52dp"
            android:layout_height="52dp"
            android:layout_gravity="center_horizontal"
            android:background="@android:color/background_light"
            android:clickable="false"
            android:contentDescription="@string/setting"
            android:scaleType="fitCenter"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.069"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.617"
            app:srcCompat="@drawable/back" />

        <TextView
            android:id="@+id/textView01_1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="益食物"
            android:textColor="@android:color/background_dark"
            android:textSize="36sp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="1.0" />
    </androidx.constraintlayout.widget.ConstraintLayout>

    <ExpandableListView
        android:id="@+id/elv"
        android:layout_width="match_parent"
        android:layout_height="354dp"
        android:layout_alignParentTop="true"
        android:layout_centerVertical="true"
        android:layout_marginTop="181dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <SearchView
        android:id="@+id/sv"
        android:layout_width="358dp"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="83dp"
        android:layout_marginEnd="27dp"
        android:layout_marginRight="27dp" />


</RelativeLayout>

下面是后台的实现：

bean层：

public class Shiwu {
private String classes;
private String name;
private String calory;
public String getClasses() {
    return classes;
}
public void setClasses(String classes) {
    this.classes = classes;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public String getCalory() {
    return calory;
}
public void setCalory(String calory) {
    this.calory = calory;
}
}

dao层：

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import com.test.bean.Shiwu;
import com.test.util.DBUtil;


public class ShowDao {
    public List<Shiwu> select(){
        Connection conn = DBUtil.getConn(); //连接数据库
        List<Shiwu> list = new ArrayList<Shiwu>();
        try {
            String sql="select * from reliang";
            Statement pstmt = (Statement) conn.createStatement();
            ResultSet rs = (ResultSet) pstmt.executeQuery(sql);
            while(rs.next()) {
                Shiwu Shiwu=new Shiwu();
                Shiwu.setClasses(rs.getString("classes"));
                Shiwu.setName(rs.getString("name"));
                Shiwu.setCalory(rs.getString("calory"));
                list.add(Shiwu);
            }
            rs.close();
            pstmt.close();
            conn.close();

        }catch(SQLException e) {
            e.printStackTrace();
        }
        return list;
    }
    public List<Shiwu> select1(String name){
        Connection conn = DBUtil.getConn(); //连接数据库
        List<Shiwu> list1 = new ArrayList<Shiwu>();
        try {
            String sql="select * from reliang where name like '%"+name+"%' ";
            Statement pstmt = (Statement) conn.createStatement();
            ResultSet rs = (ResultSet) pstmt.executeQuery(sql);
            while(rs.next()) {
                Shiwu Shiwu=new Shiwu();
                Shiwu.setClasses(rs.getString("classes"));
                Shiwu.setName(rs.getString("name"));
                Shiwu.setCalory(rs.getString("calory"));
                list1.add(Shiwu);
            }
            rs.close();
            pstmt.close();
            conn.close();
            System.out.println("ShowDaoselect1");

        }catch(SQLException e) {
            e.printStackTrace();
        }
        return list1;
    }

    
}

servlet层：

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.test.bean.Shiwu;
import com.test.dao.ShowDao;


import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;



/**
 * Servlet implementation class ShowServlet
 */
@WebServlet("/ShowServlet")
public class ShowServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public ShowServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        ShowDao sd = new ShowDao();
        List<Shiwu> list = sd.select();
        String json = JSON.toJSONString(list);
        System.out.println(json);
        PrintWriter pw=response.getWriter();
        pw.write(json);
        pw.close();
//        request.setAttribute("list", list);
//        request.getRequestDispatcher("show.jsp").forward(request, response);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

连接数据库的util层就不贴了，比较简单。

这样子展示功能就能实现了。

期间遇到的困难有：

as端与后端数据的数据传递问题，转换json格式进行传值可以解决这个问题。之前对List操作的学习不是很深入，经过这次尝试算是对List有了很多的了解。

而传递到前端的json数据进行处理花费了我大量的时间，说起来真是折腾呀。

仔细分析数据表，然后对数据该怎样处理是值得深思的，这样可以更快的解决问题。