ORM greenDAO基本用法

介紹

greenDAO is a light & fast ORM solution for Android that maps objects to SQLite databases. Being highly optimized for Android, greenDAO offers great performance and consumes minimal memory.

源碼：https://github.com/greenrobot/greenDAO
官網：http://greenrobot.org/greendao/

用法

GreenDAO例子

• 創建一個Java Library Model – greendaogenerator，類名GreenDaoGenerator

greendaogenerator/build.gradle

apply plugin: 'java'

repositories {
    mavenLocal()
    mavenCentral()
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'de.greenrobot:greendao-generator:2.0.0'
}

sourceSets {
    main {
        java {
            srcDir 'src/main/java'
        }
    }
}

artifacts {
    archives jar
}

GreenDaoGenerator.java

package com.xuie;

import de.greenrobot.daogenerator.DaoGenerator;
import de.greenrobot.daogenerator.Entity;
import de.greenrobot.daogenerator.Property;
import de.greenrobot.daogenerator.Schema;
import de.greenrobot.daogenerator.ToMany;

/**
 * Generates entities and DAOs for the example project DaoExample.
 * <p/>
 * Run it as a Java application (not Android).
 *
 * @author Markus
 */
public class GreenDaoGenerator {

    public static void main(String[] args) throws Exception {
        Schema schema = new Schema(1, "com.xuie.greendaodemo.greendao");

        addNote(schema);
        addCustomerOrder(schema);

        new DaoGenerator().generateAll(schema, "../app/src/main/java");
    }

    private static void addNote(Schema schema) {
        Entity note = schema.addEntity("Note");
        note.addIdProperty();
        note.addStringProperty("text").notNull();
        note.addStringProperty("comment");
        note.addDateProperty("date");
    }

    private static void addCustomerOrder(Schema schema) {
        Entity customer = schema.addEntity("Customer");
        customer.addIdProperty();
        customer.addStringProperty("name").notNull();

        Entity order = schema.addEntity("Order");
        order.setTableName("ORDERS"); // "ORDER" is a reserved keyword
        order.addIdProperty();
        Property orderDate = order.addDateProperty("date").getProperty();
        Property customerId = order.addLongProperty("customerId").notNull().getProperty();
        order.addToOne(customer, customerId);

        ToMany customerToOrders = customer.addToMany(order, customerId);
        customerToOrders.setName("orders");
        customerToOrders.orderAsc(orderDate);
    }
}

• 編譯Java Model

  • Run>Edit Configurations..>左上角”+”>選中application
  • Name:geendaogenerator
  • Main Class:com.xuie.GreenDaoGenerator
  • Working directory: xxx/GreenDaoDemo/greendaogenerator
  • 再點確定
    
  • 可以看到運行處出現geendaogenerator，或右鍵Java Model，執行運行
  • 可以看到，../app/src/main/java下，包名com.xuie.greendaodemo.greendao目錄中產生Java文件（記得先創建好目錄），表明運行成功

• Android Model添加

app/build.gradle

dependencies {
    // ...
    compile 'de.greenrobot:greendao:2.0.0'
}

activity_main.xml

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

    <LinearLayout
        android:id="@+id/linearLayout1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <EditText
            android:id="@+id/editTextNote"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:hint="Enter new note"
            android:imeOptions="actionDone"
            android:inputType="text"/>

        <Button
            android:id="@+id/buttonAdd"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="onMyButtonClick"
            android:text="Add"/>
    </LinearLayout>

    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

MainActivity.java

package com.xuie.greendaodemo;

import android.app.ListActivity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.CursorAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;

import com.xuie.greendaodemo.greendao.DaoMaster;
import com.xuie.greendaodemo.greendao.DaoSession;
import com.xuie.greendaodemo.greendao.Note;
import com.xuie.greendaodemo.greendao.NoteDao;

import java.text.DateFormat;
import java.util.Date;

public class MainActivity extends ListActivity {
    private EditText editText;
    private SQLiteDatabase db;
    private NoteDao noteDao;

    private SimpleCursorAdapter adapter;

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

        DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(this, "notes-db", null);
        db = helper.getWritableDatabase();
        DaoMaster daoMaster = new DaoMaster(db);
        DaoSession daoSession = daoMaster.newSession();
        noteDao = daoSession.getNoteDao();

        String textColumn = NoteDao.Properties.Text.columnName;
        String orderBy = textColumn + " COLLATE LOCALIZED ASC";
        Cursor cursor = db.query(noteDao.getTablename(),
                noteDao.getAllColumns(), null, null, null, null, orderBy);
        String[] from = {textColumn, NoteDao.Properties.Comment.columnName};
        int[] to = {android.R.id.text1, android.R.id.text2};

        adapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_2, cursor,
                from, to, CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
        setListAdapter(adapter);
        cursor.close();

        editText = (EditText) findViewById(R.id.editTextNote);
        addUiListeners();
    }


    protected void addUiListeners() {
        editText.setOnEditorActionListener(new TextView.OnEditorActionListener() {

            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                if (actionId == EditorInfo.IME_ACTION_DONE) {
                    addNote();
                    return true;
                }
                return false;
            }
        });

        final View button = findViewById(R.id.buttonAdd);
        button.setEnabled(false);
        editText.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                boolean enable = s.length() != 0;
                button.setEnabled(enable);
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }

            @Override
            public void afterTextChanged(Editable s) {
            }
        });
    }

    public void onMyButtonClick(View view) {
        addNote();
    }

    private void addNote() {
        String noteText = editText.getText().toString();
        editText.setText("");

        final DateFormat df = DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM);
        String comment = "Added on " + df.format(new Date());
        Note note = new Note(null, noteText, comment, new Date());
        noteDao.insert(note);
        Log.d("DaoExample", "Inserted new note, ID: " + note.getId());

        changeCursor();
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        noteDao.deleteByKey(id);
        Log.d("DaoExample", "Deleted note, ID: " + id);
        changeCursor();
    }

    private void changeCursor() {
        String textColumn = NoteDao.Properties.Text.columnName;
        String orderBy = textColumn + " COLLATE LOCALIZED ASC";
        Cursor cursor = db.query(noteDao.getTablename(),
                noteDao.getAllColumns(), null, null, null, null, orderBy);

        adapter.changeCursor(cursor);
        adapter.notifyDataSetChanged();
    }

}

注意

這篇博文，主要寫的其實是AS編譯Java Mode這一塊，第一次用時，可能不知道在哪裏點，像我今天就矇蔽了，怎麼老是報我錯。。。

源碼下載