greendao+Handler+ListView实现增删改查
1. 主页面UI显示
2. 访问网络接口获取数据
3. 通过Handler将数据发送到主线程
4. 将获取到的数据解析成实体类型
5. 用greendao将数据添加到数据中
6. 用greendao查询出来数据展示在主页面
7. 用greendao清空本地数据库中的数据
8. 用greendao修改部分数据
https://api.tianapi.com/wxnew/?key=8d6e3228d25298f13af4fc40ce6c9679&num=10
1.依赖：
compile 'org.greenrobot:greendao:3.2.2' compile 'com.jakewharton:butterknife:8.5.1' annotationProcessor 'com.jakewharton:butterknife-compiler:8.5.1' compile 'com.squareup.okhttp3:okhttp:3.10.0' compile 'com.google.code.gson:gson:2.2.4'
2.权限：
<uses-permission android:name="android.permission.INTERNET"/> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
3.主布局文件
<?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="com.example.dell.a0412rikao_greendao.MainActivity"> <EditText android:id="@+id/edit_id" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入ID"/> <EditText android:id="@+id/edit_name" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入用户名" android:layout_marginTop="10px"/> <EditText android:id="@+id/edit_title" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入描述" android:layout_marginTop="10px"/> <Button android:id="@+id/btn_insert" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="新增" android:layout_marginTop="10px"/> <Button android:id="@+id/btn_delete" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="删除" android:layout_marginTop="10px"/> <Button android:id="@+id/btn_updata" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="修改" android:layout_marginTop="10px"/> <Button android:id="@+id/btn_removeAll" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="清空" android:layout_marginTop="10px"/> <Button android:id="@+id/btn_queryByID" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="查询一条" android:layout_marginTop="10px"/> <Button android:id="@+id/btn_query" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="查询" android:layout_marginTop="10px"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="查询结果:" android:gravity="center_horizontal" android:layout_marginTop="10px"/> <ListView android:id="@+id/my_lv" android:layout_width="match_parent" android:layout_height="match_parent"> </ListView>
</LinearLayout>
4.Activity 的实现
package com.example.dell.a0412rikao_greendao; import android.content.SharedPreferences; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.support.v7.app.AppCompatActivity; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.ListView; import android.widget.Toast; import com.google.gson.Gson; import org.greenrobot.greendao.query.Query; import java.io.IOException; import java.util.List; import butterknife.BindView; import butterknife.ButterKnife; import butterknife.OnClick; import okhttp3.Call; import okhttp3.Callback; import okhttp3.Response; public class MainActivity extends AppCompatActivity { @BindView(R.id.edit_id) EditText edit_Id; @BindView(R.id.edit_name) EditText edit_Name; @BindView(R.id.btn_insert) Button btn_Insert; @BindView(R.id.btn_delete) Button btn_Delete; @BindView(R.id.btn_query) Button btn_Query; @BindView(R.id.my_lv) ListView my_Lv; @BindView(R.id.edit_title) EditText edit_Title; @BindView(R.id.btn_updata) Button btn_Updata; @BindView(R.id.btn_removeAll) Button btn_RemoveAll; @BindView(R.id.btn_queryByID) Button btn_QueryByID; private UserDao userDao; private List<UserBean.NewslistBean> newslist; Handler handler = new Handler() { @Override public void handleMessage(Message msg) { super.handleMessage(msg); newslist = (List<UserBean.NewslistBean>) msg.obj; if (!jinru_yes) { for (int i = 0; i < newslist.size(); i++) { User user = new User(); user.setDescription(newslist.get(i).getDescription()); user.setTitle(newslist.get(i).getTitle()); //存入同意的状态值 editor.putBoolean("jinru_yes", true); editor.commit(); userDao.insert(user); } } } }; private MyAdapter myAdapter; private SharedPreferences sharedPreferences; private SharedPreferences.Editor editor; private boolean jinru_yes; private List<User> list; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //得到SharedPreferences sharedPreferences = getSharedPreferences("Person", MODE_PRIVATE); //用来操作sharedPreferences editor = sharedPreferences.edit(); //进入的状态值 用于防止进入页面时，数据重复添加 jinru_yes = sharedPreferences.getBoolean("jinru_yes", false); ButterKnife.bind(this); //通过DaoMaster拿到DaoSession，再通过DaoSession拿到UserDao DaoMaster master = new DaoMaster(new DaoMaster.DevOpenHelper(this, "users").getWritableDatabase()); DaoSession session = master.newSession(); userDao = session.getUserDao(); //获取数据 OkhtttpUtils.doGet("https://api.tianapi.com/wxnew/?key=fe7aac932e1e94f10a4f8d0f2d5fe924&num=10", new Callback() { @Override public void onFailure(Call call, IOException e) {} @Override public void onResponse(Call call, Response response) throws IOException { String json = response.body().string(); Gson gson = new Gson(); UserBean userBean = gson.fromJson(json, UserBean.class); List<UserBean.NewslistBean> newslist = userBean.getNewslist(); //向handler发送消息 Message msg = new Message(); msg.obj = newslist; handler.sendMessage(msg); } }); } @OnClick({R.id.btn_insert, R.id.btn_delete, R.id.btn_query,R.id.btn_updata,R.id.btn_queryByID,R.id.btn_removeAll}) public void onViewClicked(View view) { switch (view.getId()) { case R.id.btn_insert: //插入的方法 insert(); //查询的方法 query(); break; case R.id.btn_delete: //删除的方法 delete(); //查询的方法 query(); break; case R.id.btn_updata: //修改的方法 updata(); //查询的方法 query(); break; case R.id.btn_removeAll: //清空所有的方法 removeAll(); //查询的方法 query(); break; case R.id.btn_queryByID: //查询一条的方法 byid(); break; case R.id.btn_query: //查询的方法 query(); break; } } //清空所有数据 private void removeAll() { userDao.deleteAll(); } //根据ID查询信息 public void byid() { String idd = edit_Id.getText().toString(); Long id = Long.valueOf(idd); User user = userDao.load(id); if(user!=null){ edit_Name.setText(user.getDescription()); edit_Title.setText(user.getTitle()); }else{ Toast.makeText(this,"数据不存在",Toast.LENGTH_SHORT).show(); } } //修改的方法 private void updata() { String id_up = edit_Id.getText().toString(); Long longid_up = Long.valueOf(id_up); String n = edit_Name.getText().toString(); String t = edit_Title.getText().toString(); User user_up = new User(); user_up.setDescription(n); user_up.setTitle(t); user_up.setId(longid_up); userDao.update(user_up); } //删除的方法 public void delete() { String idd = edit_Id.getText().toString(); Long id = Long.valueOf(idd); userDao.deleteByKey(id); myAdapter.notifyDataSetChanged(); } //插入的方法 public void insert() { String name = edit_Name.getText().toString(); String title = edit_Title.getText().toString(); User user = new User(); user.setDescription(name); user.setTitle(title); userDao.insert(user); } //查询的方法 public void query() { list = userDao.loadAll(); //设置适配器 myAdapter = new MyAdapter(MainActivity.this, list); my_Lv.setAdapter(myAdapter); } }5.适配器
package com.example.dell.a0412rikao_greendao; import android.content.Context; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.TextView; import java.util.List; public class MyAdapter extends BaseAdapter{ Context context; List<User> list; public MyAdapter(Context context, List<User> list) { this.context=context; this.list=list; } @Override public int getCount() { return list.size(); } @Override public Object getItem(int i) { return list.get(i); } @Override public long getItemId(int i) { return i; } @Override public View getView(int i, View view, ViewGroup viewGroup) { MyViewHolder holder; if(view==null){ holder = new MyViewHolder(); view = View.inflate(context, R.layout.item, null); holder.id=view.findViewById(R.id.text_id); holder.name=view.findViewById(R.id.text_name); holder.title=view.findViewById(R.id.text_title); view.setTag(holder); }else{ holder= (MyViewHolder) view.getTag(); } holder.id.setText(list.get(i).getId()+""); holder.name.setText(list.get(i).getTitle()); holder.title.setText(list.get(i).getDescription()); return view; } class MyViewHolder{ TextView id,title,name; } }6.网络获取数据的Bean(大)
package com.example.dell.a0412rikao_greendao; import java.util.List; public class UserBean { private int code; private String msg; private List<NewslistBean> newslist; public int getCode() { return code; } public void setCode(int code) { this.code = code; } public String getMsg() { return msg; } public void setMsg(String msg) { this.msg = msg; } public List<NewslistBean> getNewslist() { return newslist; } public void setNewslist(List<NewslistBean> newslist) { this.newslist = newslist; } public static class NewslistBean { private String ctime; private String title; private String description; private String picUrl; private String url; public String getCtime() { return ctime; } public void setCtime(String ctime) { this.ctime = ctime; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public String getPicUrl() { return picUrl; } public void setPicUrl(String picUrl) { this.picUrl = picUrl; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } } }7.网络获取数据的Bean(手动封装)
package com.example.dell.a0412rikao_greendao; import org.greenrobot.greendao.annotation.Entity; import org.greenrobot.greendao.annotation.Id; import org.greenrobot.greendao.annotation.Generated; /** * Created by dell on 2018/4/13. */ @Entity public class User { @Id(autoincrement = true) private Long id; private String title; private String description; @Generated(hash = 718037864) public User(Long id, String title, String description) { this.id = id; this.title = title; this.description = description; } @Generated(hash = 586692638) public User() { } public Long getId() { return this.id; } public void setId(Long id) { this.id = id; } public String getTitle() { return this.title; } public void setTitle(String title) { this.title = title; } public String getDescription() { return this.description; } public void setDescription(String description) { this.description = description; } }8.OkhhtP的封装
package com.example.dell.a0412rikao_greendao; import android.os.Environment; import java.io.File; import java.util.Map; import java.util.concurrent.TimeUnit; import okhttp3.Cache; import okhttp3.Callback; import okhttp3.FormBody; import okhttp3.MediaType; import okhttp3.MultipartBody; import okhttp3.OkHttpClient; import okhttp3.Request; import okhttp3.RequestBody; import static android.R.string.ok; import static android.os.Build.VERSION_CODES.M; /** * Created by Administrator on 2018/3/8. */ public class OkhtttpUtils { //单例模式，把构造方法进行私有化 private OkhtttpUtils(){}; static OkHttpClient client; public static OkHttpClient getInstance(){ if (client==null) { //更加安全 synchronized (OkhtttpUtils.class) { //缓存的地方 mnt/sdcard File file = new File(Environment.getExternalStorageDirectory(), "cache11"); client = new OkHttpClient().newBuilder() .readTimeout(3000, TimeUnit.SECONDS) //设置读取超时时间 .connectTimeout(3000, TimeUnit.SECONDS) //设置连接的超时时间 .cache(new Cache(file, 10 * 1024)) .build(); } } return client; } /** * get请求 * Callback 是一个接口 */ public static void doGet(String url, Callback callback){ //1:拿到okhttpclient 对像 OkHttpClient client = getInstance(); //2:进行请求的操作 Request request = new Request.Builder() .url(url) .build(); client.newCall(request).enqueue(callback); } //post请求 /** * * @param url 请求的地址 * @param parms 请求的参数 * @param callback callback */ public static void doPost(String url, Map<String,String> parms,Callback callback){ //得到客户端的对像 OkHttpClient client = getInstance(); //不是FormBody，而是一个Builder FormBody.Builder body = new FormBody.Builder(); //key value for (String key:parms.keySet()){ //value的值 body.add(key,parms.get(key)); } Request request = new Request.Builder() .url(url) .post(body.build()) .build(); client.newCall(request).enqueue(callback); } //用来上传图片的 //url , 图片 ，参数 Callback public static void upImage(String url,File file,String filenName,Map<String,String> params,Callback callback){ OkHttpClient client = getInstance(); //requestBody的实现类 Formbody MultipartBody.Builder builder = new MultipartBody.Builder(); if (params!=null){ for (String key :params.keySet()){ builder.addFormDataPart(key,params.get(key)); } } //设置类型 builder.setType(MultipartBody.FORM); builder.addFormDataPart("file",filenName,RequestBody.create(MediaType.parse("application/octet-stream"),file)); // builder.setType(MultipartBody.FORM); // builder.addFormDataPart("file",filenName,RequestBody.create(MediaType.parse("application/octet-stream"),file)); //builder.addFormDataPart("file","aa.png",builder.build()); Request request = new Request.Builder() .url(url) .post(builder.build()) .build(); client.newCall(request).enqueue(callback); } }9.显示数据的ListView 的条目布局
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:padding="10px"> <TextView android:id="@+id/text_id" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="1"/> <TextView android:id="@+id/text_title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_toRightOf="@id/text_id" android:layout_marginLeft="20px" android:text="孟大明白"/> <TextView android:id="@+id/text_name" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/text_title" android:text="张靓颖被爆离婚：什么样的爱情，一定不能要？"/> </RelativeLayout>