团队开发冲刺第二阶段（最终日总结）

　　今天是规定的团队开发冲刺第二阶段的最后一天，冲刺时期每日做事已在团队博客里记录，我没有更新个人博客，上周比较忙，不少学科到了期末交作业的时候，针对Android的代码学习量比较少，每日打卡也说不上什么东西，就想着最后一天做一个小总结。因为时间有限，这段时间完成的是使用ListView遍历显示存储在数据库中的用户笔记记录，点击相应item会进入笔记详细界面，显示笔记和附上的图片缩略图，点击缩略图可以查看大图，提供返回界面的按钮。目前做的这个只是一个初稿，算是实现了功能的雏形，还需要完善删除功能和界面优化等等，下面先看一下初稿的样子吧。

代码：

主页面：activity_main.xml

只有一个TextView显示大标题，和ListView组件

<?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:orientation="horizontal"
        >

        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:gravity="center_horizontal"
            android:layout_weight="1"
            android:hint="标题"
            android:textSize="30sp"
            android:textColor="#3b3b3b"
            ></TextView>

        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:gravity="center_horizontal"
            android:layout_weight="1"
            android:hint="学科"
            android:textSize="30sp"
            android:textColor="#3b3b3b"
            ></TextView>
    </LinearLayout>
    <View
        android:layout_width="match_parent"
        android:layout_height="2px"
        android:background="#3b3b3b"></View>
    <ListView
        android:id="@+id/list_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="none"
        android:divider="#CCCCCC"
        android:dividerHeight="2px"
        ></ListView>

</LinearLayout>

笔记页面：activity_note_view.xml

根据传过来的信息去服务器端拿到图片和文件数据，这里固定设置一个ImageView和一个TextView，用来查看实现效果，最终实现的样式需要ImageView动态添加。

<?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">

    <ImageView
        android:id="@+id/trypng"
        android:layout_width="120dp"
        android:layout_height="120dp"
        ></ImageView>

    <TextView
        android:id="@+id/trytxt"
        android:layout_width="match_parent"
        android:layout_height="240dp"
        android:hint="读取文件内容"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/exit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="返回"
        ></Button>

</LinearLayout>

查看大图页面：dialog_photo.xml

这里在点击缩略图后实现查看大图的功能。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ImageView
        android:id="@+id/large_image"
        android:layout_width="match_parent"
        android:layout_height="700dp"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"></ImageView>

</LinearLayout>

list设置：list_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal">
    <TextView
        android:id="@+id/li_title"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:layout_marginTop="10sp"
        android:layout_marginBottom="10sp"
        android:layout_weight="1"
        android:hint="标题"
        android:textSize="20sp"
        android:textColor="#3b3b3b"
        ></TextView>

    <TextView
        android:id="@+id/li_kemu"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:layout_marginTop="10sp"
        android:layout_marginBottom="10sp"
        android:layout_weight="1"
        android:hint="学科"
        android:textSize="20sp"
        android:textColor="#3b3b3b"
        ></TextView>

</LinearLayout>

java后台代码：

MainActivity.java：这里实现ListView显示，点击事件等，连接的是本地的servlet。

package com.example.toas;

import androidx.appcompat.app.AlertDialog;
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.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;

import org.json.JSONArray;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    private TextView li_title,li_kemu;
    private ListView list_view;
    private ArrayList<MyNoteBean> listData;
    private MyNoteAdapter adapter;
    private Handler handler;



    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
        return inflater.inflate(R.layout.activity_main,container,false);
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        li_title = (TextView)findViewById(R.id.li_title);
        li_kemu = (TextView)findViewById(R.id.li_kemu);
        list_view = (ListView)findViewById(R.id.list_view);
        listData = new ArrayList<MyNoteBean>();

        handler = new Handler(){
            public void handleMessage(Message msg){
                super.handleMessage(msg);
                if(msg.what==1){
                    adapter=new MyNoteAdapter(MainActivity.this,listData);
                    list_view.setAdapter(adapter);
                    adapter.notifyDataSetChanged();
                }
            }
        };
        final String path="http://192.168.101.18:8080/CloudNote/MyNoteServlet";
        //使用HttpURLConnection需要子线程
        new Thread(new Runnable() {
            @Override
            public void run() {
                //从上一个页面拿到输入的日期数据
                HttpURLConnection conn=null;
                try{
                    URL url=new URL(path);
                    conn=(HttpURLConnection)url.openConnection();
                    //设置post格式，这里格式要跟servlet里一致
                    conn.setRequestMethod("POST");
                    //设置超时时间
                    conn.setConnectTimeout(5000);
                    conn.setReadTimeout(5000);
                    //post格式不能用缓存
                    conn.setUseCaches(false);
                    conn.setDoInput(true);
                    String data="user="+"try";
                    //将传给servlet的数据写入传输
                    OutputStream out=conn.getOutputStream();
                    //这里注意要更改传输数据的格式，getBytes()
                    out.write(data.getBytes());
                    out.flush();
                    out.close();
                    conn.connect();

                    //这里开始接收从servlet里传回来的数据
                    BufferedReader reader=new BufferedReader(new InputStreamReader(conn.getInputStream()));
                    String line=null;
                    //传回来的是一个JSONArray类型的数据，需要对其进行解析
                    if((line=reader.readLine())!=null){
                        //开始解析
                        JSONArray jsonArray=new JSONArray(line);
                        for(int i=0;i<jsonArray.length();i++){
                            JSONObject jsonObject=jsonArray.getJSONObject(i);
                            int id=jsonObject.getInt("id");
                            String nianji=jsonObject.getString("nianji");
                            String kemu=jsonObject.getString("kemu");
                            String title=jsonObject.getString("title");
                            String note=jsonObject.getString("note");
                            String image1=jsonObject.getString("image1");
                            String image2=jsonObject.getString("image2");
                            String image3=jsonObject.getString("image3");
                            String SEE=jsonObject.getString("SEE");

                            MyNoteBean mnb = new MyNoteBean();
                            mnb.setTitle(title);
                            mnb.setKemu(kemu);
                            mnb.setId(id);
                            mnb.setNianji(nianji);
                            mnb.setNote(note);
                            mnb.setImage1(image1);
                            mnb.setImage2(image2);
                            mnb.setImage3(image3);
                            mnb.setSEE(SEE);
                            listData.add(mnb);
                        }
                    }
                    Message msg = new Message();
                    msg.what = 1;
                    handler.sendMessage(msg);
                }catch(Exception e){
                    e.printStackTrace();
                }
            }
        }).start();

        list_view.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                MyNoteBean MNB = listData.get(position);
                Intent intent = new Intent(MainActivity.this,NoteView.class);
                intent.putExtra("note",MNB.getNote());
                intent.putExtra("img1",MNB.getImage1());
                startActivity(intent);
            }
        });
    }
}

NoteView.java：实现笔记的读取文件和图片，显示功能，缩略图查看大图功能。

package com.example.toas;

import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

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

public class NoteView extends AppCompatActivity {
    private TextView trytxt;
    private Button exit;
    private ImageView trypng;
    private Myhandler handler1;
    private Txthandler handler2;

    class Myhandler extends Handler {
        public void handleMessage(Message msg) {
            trypng = (ImageView) findViewById(R.id.trypng);
            trypng.setImageBitmap((Bitmap) msg.obj);
        }
    }

    class Txthandler extends Handler {      //文本handler
        public void handleMessage(Message msg) {
            trytxt = (TextView) findViewById(R.id.trytxt);
            trytxt.setText(msg.obj.toString());
        }
    }

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

        exit = (Button) findViewById(R.id.exit);
        handler1 = new Myhandler();
        handler2 = new Txthandler();

        Intent intentdata=getIntent();
        final String inote=intentdata.getStringExtra("note");
        final String iimg1=intentdata.getStringExtra("img1");

        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    String path = "http://39.101.190.190:8080/filesource/"+iimg1;
                    URL url = new URL(path);
                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                    conn.setRequestMethod("GET");
                    conn.setConnectTimeout(8000);
                    conn.setReadTimeout(8000);
                    conn.connect();
                    if (conn.getResponseCode() == 200) {
                        InputStream is = conn.getInputStream();
                        Bitmap bm = BitmapFactory.decodeStream(is);
                        seeBigimg(bm);
                        Message msg = new Message();
                        msg.obj = bm;
                        handler1.sendMessage(msg);
                    }
                } catch (MalformedURLException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();

        new Thread(new Runnable() {
            @Override
            public void run() {     //文本读取调用
                String txtpath = "http://39.101.190.190:8080/filesource/"+inote;
                try {
                    URL turl = new URL(txtpath);
                    HttpURLConnection cont = (HttpURLConnection) turl.openConnection();
                    cont.setReadTimeout(8000);
                    cont.setConnectTimeout(8000);
                    cont.connect();
                    InputStream input = cont.getInputStream();
                    BufferedReader in = new BufferedReader(new InputStreamReader(input));
                    String line = null;
                    StringBuffer sb = new StringBuffer();
                    while ((line = in.readLine()) != null) {
                        sb.append(line);
                    }
                    if (cont.getResponseCode() == 200) {
                        Message msg = new Message();
                        msg.obj = sb;
                        handler2.sendMessage(msg);
                    }
                } catch (MalformedURLException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();

        exit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(NoteView.this,MainActivity.class);
                startActivity(intent);
            }
        });
    }

    private void seeBigimg(final Bitmap bm) {
        trypng = (ImageView) findViewById(R.id.trypng);
        trypng.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View paramView) {
                LayoutInflater inflater = LayoutInflater.from(NoteView.this);
                View imgEntryView = inflater.inflate(R.layout.dialog_photo,null);
                final AlertDialog dialog = new AlertDialog.Builder(NoteView.this).create();
                ImageView img1 = (ImageView)imgEntryView.findViewById(R.id.large_image);
                img1.setImageBitmap(bm);
                dialog.setView(imgEntryView);
                dialog.show();

                imgEntryView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View paramView) {
                        dialog.cancel();
                    }
                });
            }
        });
    }
}

MyNoteBean.java：bean

package com.example.toas;

public class MyNoteBean {
    private int Id;
    private String User;
    private String Nianji;
    private String Kemu;
    private String Title;
    private String Note;
    private String Image1;
    private String Image2;
    private String Image3;
    private String SEE;

    public int getId(){ return Id; }
    public void setId(int id){ Id=id; }
    public String getUser(){ return User; }
    public void setUser(String user){ User=user; }
    public String getNianji(){ return Nianji; }
    public void setNianji(String nianji){ Nianji=nianji; }
    public String getKemu(){ return Kemu; }
    public void setKemu(String kemu){ Kemu=kemu; }
    public String getTitle(){
        return Title;
    }
    public void setTitle(String title){ Title=title; }
    public String getNote(){
        return Note;
    }
    public void setNote(String note){ Note=note; }
    public String getImage1(){return Image1;};
    public void setImage1(String image1){Image1=image1;}
    public String getImage2(){return Image2;}
    public void setImage2(String image2){Image2=image2;}
    public String getImage3(){return Image3;}
    public void setImage3(String image3){Image3=image3;}
    public String getSEE(){return SEE;}
    public void setSEE(String see){SEE=see;}
}

MyNoteAdapter.java：适配器

package com.example.toas;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.ArrayList;

public class MyNoteAdapter extends BaseAdapter {
    private Context context;
    private ArrayList<MyNoteBean> listData;

    public MyNoteAdapter(Context context,ArrayList<MyNoteBean> listData){
        this.context=context;
        this.listData=listData;
    }

    @Override
    public int getCount() {  return listData.size(); }

    @Override
    public Object getItem(int position) { return listData.get(position); }

    @Override
    public long getItemId(int position) { return position; }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        MyNoteBean MNB = (MyNoteBean) getItem(position);
        ViewHolder viewHolder=null;
        if(convertView==null){
            LayoutInflater inflater=LayoutInflater.from(context);
            //这里将ListView的格式xml文件名称写入，名字千万别写错，否则调用后显示的格式会发生错误
            convertView=inflater.inflate(R.layout.list_item,null);
            viewHolder=new ViewHolder();
            viewHolder.li_title=(TextView)convertView.findViewById(R.id.li_title);
            viewHolder.li_kemu=(TextView)convertView.findViewById(R.id.li_kemu);
            convertView.setTag(viewHolder);
        }
        viewHolder=(ViewHolder)convertView.getTag();
        MyNoteBean model=listData.get(position);
        viewHolder.li_title.setText(model.getTitle());
        viewHolder.li_kemu.setText(model.getKemu());
        return convertView;
    }
}
class ViewHolder{
    public TextView li_title;
    public TextView li_kemu;
}

效果：

 最后我改动了一下之前写的记录功能的代码，以前实现的记录功能会在手机内存里生成txt文件和png文件（在特定的文件夹内）。与成员协商后决定在实现提交的同时删除这些生产文件。代码如下：

声明对象，1234分别对应txt，图片1，图片2，图片3

private String del1,del2,del3,del4;//删除文件用

使用OkHttp上传的同时给对象赋值：【del1,del2,del3,del4】

String noteuser = user_str+"_note";
                File Notefile = doString(note_str,noteuser);
                del1 = Environment.getExternalStorageDirectory().toString()+"/CloudNoteTXT/"+Notefile.getName();
                builder.addFormDataPart("note",Notefile.getName(),RequestBody.create(NoteType,Notefile));

                //图片文件,设定最多上传3张，不包括+号图片。
                int pic_i=0;
                for(HashMap<String,Bitmap>pic:imageItem){
                    Set<String> set=pic.keySet();
                    for(String key:set){
                        if(pic_i==0){
                            //跳过默认的+号图片
                            pic_i++;
                            continue;
                        }
                        //取出bitmap，转换成file，上传
                        else if(pic_i==1){
                            Bitmap fbm1 = pic.get(key);
                            //设置文件命名前缀部分
                            String image1user = user_str+"_image1";
                            //调用方法生成图片文件
                            File dofile = doImage(fbm1,image1user);
                            del2 = Environment.getExternalStorageDirectory().toString()+"/CloudNoteImage/"+dofile.getName();
                            builder.addFormDataPart("image1",dofile.getName(),RequestBody.create(PNG,dofile));
                            pic_i++;
                        }
                        else if(pic_i==2){
                            Bitmap fbm2 = pic.get(key);
                            //设置文件命名前缀部分
                            String image2user = user_str+"_image2";
                            //调用方法生成图片文件
                            File dofile = doImage(fbm2,image2user);
                            del3 = Environment.getExternalStorageDirectory().toString()+"/CloudNoteImage/"+dofile.getName();
                            builder.addFormDataPart("image2",dofile.getName(),RequestBody.create(PNG,dofile));
                            pic_i++;
                        }
                        else if(pic_i==3){
                            Bitmap fbm3 = pic.get(key);
                            //设置文件命名前缀部分
                            String image3user = user_str+"_image3";
                            //调用方法生成图片文件
                            File dofile = doImage(fbm3,image3user);
                            del4 = Environment.getExternalStorageDirectory().toString()+"/CloudNoteImage/"+dofile.getName();
                            builder.addFormDataPart("image3",dofile.getName(),RequestBody.create(PNG,dofile));
                            pic_i++;
                        }
                    }
                }

删除文件的方法：

 //删除文件
    public void deletefile(String df){
        File file = new File(df);
        if(file.isFile()){
            file.delete();
        }
    }

调用删除文件方法在OkHttp完成之后，注意要对对象进行非空判断，否则运行出错：

@Override
                    public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                        Log.i("TRYxxx","连接的消息"+response.message());
                        if(response.isSuccessful()){
                            Log.i("TRYxxx","连接成功");
                            //okhttp里直接调用Toast会报错
                            handler.post(new Runnable() {
                                @Override
                                public void run() {
                                    Toast.makeText(MainActivity.this, "上传成功", Toast.LENGTH_SHORT).show();
                                }
                            });
                            deletefile(del1);
                            if(del2!=null){
                                deletefile(del2);
                            }
                            if(del3!=null){
                                deletefile(del3);
                            }
                            if(del4!=null){
                                deletefile(del4);
                            }
                        }
                    }