- 新建數據庫跟表。
- 新建項目,在res目錄下新建raw文件夾,將素材中idioms.db數據庫複製到該文件夾下,這是因爲raw文件夾中的東西,Android會原封不動的拷貝到程序中,而不會轉換爲二進制文件。
在db包下新建一個DBOpenHelper類,代碼如下:
package cn.edu.bztc.happyidiom.db;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import com.example.happyidom.R;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.os.Environment;
import android.util.Log;
/**
* 實現將數據庫文件從raw目錄下拷貝到手機裏存放數據庫的位置
* @author zy
*
*/
public class DBOpenHelper {
private final int BUFFER_SIZE=400000;//緩衝區的大小
public static final String DB_NAME="idioms.db";//保存的數據庫文件名
public static final String PACKAGE_NAME="com.example.happyidom";//應用的包名
//如可查找應用的包名,????出現的錯誤
public static final String DB_PATH="/data"
+Environment.getDataDirectory().getAbsolutePath()+"/"
+PACKAGE_NAME+"/databases";//在手機存放數據庫的位置
private Context context;
public DBOpenHelper(Context context){
this.context=context;
}
public SQLiteDatabase openDatabase(){
try{
File myDataPath=new File(DB_PATH);
if(!myDataPath.exists()){
myDataPath.mkdirs();//如果沒有這個目錄則創建
}
String dbfile = myDataPath+"/"+DB_NAME;
if(!(new File(dbfile).exists())){//判斷數據庫文件是否存在,若不存在則執行導入
//否則直接打開數據庫
InputStream is = context.getResources().openRawResource(R.raw.idioms);
FileOutputStream fos=new FileOutputStream(dbfile);
byte[] buffer= new byte[BUFFER_SIZE];
int count=0;
while((count=is.read(buffer))>0){
fos.write(buffer, 0, count);
}
fos.close();
is.close();
}
SQLiteDatabase db=SQLiteDatabase.openOrCreateDatabase(dbfile, null);
return db;
}catch(FileNotFoundException e){
Log.e("Database","File not found");
e.printStackTrace();
}catch (IOException e) {
Log.e("Database","IO exception");
e.printStackTrace();
}
return null;
}
}
以上代碼實現的功能主要是使用輸入輸出流將idioms.db複製到手機中默認存放數據庫的位置,爲驗證是否成功搭建單元測試環境,
修改AndroidManifest.xml
</application>
<instrumentation
android:name="android.test.InstrumentationTestRunner"
android:targetPackage="com.example.happyidom" >
</instrumentation>
</manifest>
在test下新DBOpenHelperTestCase
package cn.edu.bztc.happyidiom.test;
import cn.edu.bztc.happyidiom.db.DBOpenHelper;
import android.test.AndroidTestCase;
public class DBOpenHelperTest extends AndroidTestCase{
public void testDBCopy(){
DBOpenHelper dbOpenHelper=new DBOpenHelper(getContext());
dbOpenHelper.openDatabase();
}
}
src目錄下新建七個包,adapter包用於存放適配器,activity包用於存放頁面活動相關的代碼,dao包用於存放數據操作相關的代碼,db包用於數據庫相關的代碼,util包用於存放所有工具相關的代碼,test包用於存放單元測試類,entity用於存放實體類
首先在strings.xml頁面定義所需要的文本信息。
strings.xml頁面內容如下:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">HappyIdom</string>
<string name="action_settings">Settings</string>
<string name="hello_world">Hello world!</string>
<string name="title_study">學習</string>
<string name="title_search">搜搜</string>
<string name="title_game">遊戲</string>
<string name="title_save">收藏</string>
<string name="title_help">幫助</string>
<string-array name="category">
<item>動物類</item>
<item>自然類</item>
<item>人物類</item>
<item>季節類</item>
<item>數字類</item>
<item>寓言類</item>
<item>其他</item>
</string-array>
<string-array name="name">
<item>學習</item>
<item>搜搜</item>
<item>遊戲</item>
<item>收藏</item>
<item>幫助</item>
</string-array>
<string name="title_activity_study">StudyActivity</string>
<string name="title_activity_study_animal">StudyAnimalActivity</string>
<string name="title_activity_ma">MaActivity</string>
<string name="title_activity_query">QueryActivity</string>
</resources>
- 在entity實體包下建立相應的Animal類,並建立AnimalDao類,會把一些常用的數據庫操作類封裝起來,方便以後的使用
AnimalDao代碼如下:
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;
import android.view.accessibility.AccessibilityNodeInfo;
public class AnimalDao {
private static AnimalDao animalDao;
private SQLiteDatabase db;
/**
* 將構造方法私有化
*/
private AnimalDao(Context context){
DBOpenHelper dbHelper=new DBOpenHelper(context);
db=dbHelper.openDatabase();
}
/**
* 獲取AnimalDao的示例
*/
public synchronized static AnimalDao getInstance(Context context){
if(animalDao==null){
animalDao=new AnimalDao(context);
}
return animalDao;
}
/**
* 從數據庫讀取所有的動物類成語
*/
public List<Animal> getAllAnimals(){
List<Animal> list = new ArrayList<Animal>();
Cursor cursor=db.query("animal", null, null, null, null, null, null);
if(cursor.moveToFirst()){
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")));
list.add(animal);
}while(cursor.moveToNext());
}
return list;
}
}
Animal類代碼如下:
package cn.edu.bztc.happyidiom.entity;
public class Animal {
private int id;
private String name;//成語名稱
private String pronounce;//成語發音
private String explain;//成語解釋
private String antonym;//反義詞
private String homoionym;//同義詞
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;
}
}
編輯單元測試:
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 AnimalTest extends AndroidTestCase {
public void textGetAllAnimals(){
AnimalDao animalDao=AnimalDao.getInstance(getContext());
List<Animal> animals=animalDao.getAllAnimals();
System.out.println(animals.size());
for(Animal animal:animals){
System.out.println(animal.getName());
}
}
}