乐学成语二

         乐

<p><strong>学成语</strong></p><p><strong>实体类</strong></p><p><strong> 在<span style="font-family: Calibri;">entity</span><span style="font-family: 宋体;">包下新建一个</span><span style="font-family: Calibri;">Animal</span><span style="font-family: 宋体;">类。</span></strong></p><p><strong>对应字段有<span style="font-family: Calibri;">get</span><span style="font-family: 宋体;">和</span><span style="font-family: Calibri;">set</span><span style="font-family: 宋体;">方法实现</span></strong></p>

</pre><pre name="code" class="java">package cn.edu.bztc.happyidiom.entity;public class Animal {private int id;private String name;//成语名称private String pronounce;//成语发音private String explain;//成语解释private String antonym;//反义词private String homoionym;//同义词private String derivation;//源自private String examples;//例子public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getPronounce() {return pronounce;}public void setPronounce(String pronounce) {this.pronounce = pronounce;}public String getExplain() {return explain;}public void setExplain(String explain) {this.explain = explain;}public String getAntonym() {return antonym;

}public void setAntonym(String antonym) {this.antonym = antonym;}public String getHomoionym() {return homoionym;}public void setHomoionym(String homoionym) {this.homoionym = homoionym;}public String getDerivation() {return derivation;}public void setDerivation(String derivation) {this.derivation = derivation;}public String getExamples() {return examples;}public void setExamples(String examples) {this.examples = examples;}}

创建一个AnimalDao类。

把一些常用的数据库操作封装起来。

AnimalDao是一个单例类，将它的构造私有化，提供getInstance（）方法来获取AnimalDao实例。

package cn.edu.bztc.happyidiom.dao;import java.util.ArrayList;import java.util.List;import cn.edu.bztc.happyidiom.db.DBOpenHelper;import cn.edu.bztc.happyidiom.entity.Animal;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;public class AnimalDao {private static AnimalDao animaiDao;private SQLiteDatabase db;/*将构造方法私有化*/private AnimalDao(Context context){DBOpenHelper dbHelper=new DBOpenHelper(context);db=dbHelper.openDatabase();}/*获取AnimalDao的实例*/public synchronized static AnimalDao getInstance(Context context){if(animaiDao==null){animaiDao=new AnimalDao(context);}return animaiDao;}/*从数据库读取所有的动物类成语*/public List<Animal> getAllAnimals(){List<Animal> list=new ArrayList<Animal>();Cursor cursor=db.query("animal",null,null,null,null,null,null);if(cursor.moveToNext()){do{Animal animal=new Animal();animal.setId(cursor.getInt(cursor.getColumnIndex("_id")));animal.setName(cursor.getString(cursor.getColumnIndex("name")));animal.setPronounce(cursor.getString(cursor.getColumnIndex("pronounce")));animal.setAntonym(cursor.getString(cursor.getColumnIndex("antonym")));animal.setHomoionym(cursor.getString(cursor.getColumnIndex("homoionym")));animal.setDerivation(cursor.getString(cursor.getColumnIndex("derivation")));animal.setExamples(cursor.getString(cursor.getColumnIndex("examples")));animal.setExplain(cursor.getString(cursor.getColumnIndex("explain")));list.add(animal);}while(cursor.moveToNext());}return list;}}

编写单元测试类AnimalDaoTest继承AndroidTestCase

package cn.edu.bztc.happyidiom.test;

 

import java.util.List;

 

import cn.edu.bztc.happyidiom.dao.AnimalDao;

import cn.edu.bztc.happyidiom.entity.Animal;

import android.test.AndroidTestCase;

 

public class AnimalDaoTest extends AndroidTestCase{

public void testGetAllAnimals(){

AnimalDao animalDao=AnimalDao.getInstance(getContext());

List<Animal> animals=animalDao.getAllAnimals();

System.out.println(animals.size());

for(Animal animal:animals){

System.out.println(animal.getName());

}

}

}