《android的SQLite与文件下载》
下面是我程序的图片
下面是我的程序代码：
主函数:
package com.example.allpor;
import com.example.database.DataBase;
import android.os.Bundle;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
/**
* 这是主要的Activity
* 主要负责的就是模拟登录过程
* @author 吕檀溪
*
*/
public class MainActivity extends Activity {
private DataBase base;
private Button butOk;
private Button butCl;
private EditText nameText;
private EditText pwdText;
private SQLiteDatabase db;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
butOk=(Button) findViewById(R.id.ok);
butCl=(Button) findViewById(R.id.clear);
nameText=(EditText) findViewById(R.id.name);
pwdText=(EditText) findViewById(R.id.pwd);
base=new DataBase(this, "mine", null, 1);
db=base.getReadableDatabase();
base.onCreate(db);
ContentValues values=new ContentValues();
values.put("name", "lvtanxi");
values.put("pwd", "jaychou");
db.insert("demo_user", null, values);
ButtonClick click=new ButtonClick();
butOk.setOnClickListener(click);
butCl.setOnClickListener(click);
}
/**
* 创建Button的点击事件监听器
* @author 吕檀溪
*
*/
class ButtonClick implements OnClickListener{
@Override
public void onClick(View view) {
Button but=(Button) view;
if(R.id.ok==but.getId()){
String name=nameText.getText().toString();
String pwd=pwdText.getText().toString();
String[] array={name,pwd};
Cursor cursor=db.rawQuery("select * from demo_user where name=? and pwd=?", array);
if(cursor.moveToNext()){
Toast.makeText(MainActivity.this, R.string.success, Toast.LENGTH_SHORT).show();
Intent intent=new Intent();
intent.putExtra("array", array);
intent.setClass(MainActivity.this, ShowDown.class);
startActivity(intent);
}else{
Toast.makeText(MainActivity.this, R.string.down, Toast.LENGTH_SHORT).show();
}
}else{
nameText.setText("");
pwdText.setText("");
}
}
}
}
第二个Activity:
package com.example.allpor;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.example.database.DownLoad;
import android.app.Activity;
import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
import android.widget.RadioGroup.OnCheckedChangeListener;
/**
* 进行下载的页面
* @author 吕檀溪
*
*/
public class ShowDown extends Activity{
private Button but;
private CheckBox box1;
private CheckBox box2;
private CheckBox box3;
private RadioGroup group;
private TextView text;
private List<String> list;
private Map<String, String> map;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.show);
box1=(CheckBox) findViewById(R.id.box1);
box2=(CheckBox) findViewById(R.id.box2);
box3=(CheckBox) findViewById(R.id.box3);
but=(Button) findViewById(R.id.load);
group=(RadioGroup) findViewById(R.id.grop);
text=(TextView) findViewById(R.id.user);
Intent intent=getIntent();
String[] array=intent.getStringArrayExtra("array");
text.setText("欢迎:"+array[0]+"; 您的密码是:"+array[1]);
list=new ArrayList<String>();
map=new HashMap<String, String>();
Resources resources=getResources();
map.put(resources.getString(R.string.box1), "http://61.164.160.62:8080/1/1/3163/wo99.com_1200916179836395.mp3?tflag=1392807562");
map.put(resources.getString(R.string.box2), "http://storage11.ocdn.kugou.com/M00/04/8A/e4Olo04Avl7VWT-KACkYABpLCnI118.mp3 ");
map.put(resources.getString(R.string.box3), "http://flv.whcedu.cn/files/2012-12/10/10184450552.mp3 ");
CheckBoxChange boxChange=new CheckBoxChange();
box1.setOnCheckedChangeListener(boxChange);
box2.setOnCheckedChangeListener(boxChange);
box3.setOnCheckedChangeListener(boxChange);
group.setOnCheckedChangeListener(new RadioGroupChange());
but.setOnClickListener(new ButtonClick());
}
/**
* Button的点击事件
* @author 吕檀溪
*
*/
class ButtonClick implements OnClickListener{
@Override
public void onClick(View view) {
for (String str : list) {
DownLoad load=new DownLoad();
load.toRun(map.get(str), "myMp3", str+".mp3");
}
}
}
/**
* RadioButton的Change事件
* @author 吕檀溪
*
*/
class RadioGroupChange implements OnCheckedChangeListener{
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
RadioButton radio=(RadioButton) group.findViewById(checkedId);
System.out.println(radio.getText().toString());
}
}
/**
* CheckBox的Change事件
* @author 吕檀溪
*
*/
class CheckBoxChange implements android.widget.CompoundButton.OnCheckedChangeListener{
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
CheckBox box=(CheckBox) buttonView;
String msg=box.getText().toString();
if(isChecked){
list.add(msg);
}else{
list.remove(msg);
}
}
}
}
创建数据库的类：
package com.example.database;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
/**
* 创建android的SQLite数据库
* @author 吕檀溪
*
*/
public class DataBase extends SQLiteOpenHelper{
public DataBase(Context context, String name, CursorFactory factory,
int version) {
super(context, name, factory, version);
}
//执行创建数据库的语句
@Override
public void onCreate(SQLiteDatabase db) {
System.out.println("---->onCreate");
db.execSQL("drop table if exists demo_user");
db.execSQL("create table demo_user(id integer primary key autoincrement,name text,pwd text)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
}
下载的线程类：
package com.example.database;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import android.os.Environment;
/**
* 下载歌曲的线程类
* @author 吕檀溪
*
*/
public class DownLoad implements Runnable{
private URL url;
private String path;
private String urlStr;
private String dirName;
private String fileName;
//在实例化线程类的同时得到外部存储器的路径
public DownLoad() {
path=Environment.getExternalStorageDirectory()+File.separator;
}
/**
* 启动线程
* @param url 下载文件的地址
* @param dirName 文件夹的名字
* @param fileName 下载文件的名字
*/
public void toRun(String url,String dirName,String fileName){
this.urlStr=url;
this.dirName=dirName;
this.fileName=fileName;
new Thread(this).start();
}
@Override
public void run() {
int num=downFile();
System.out.println("-------->"+num);
}
/**
* 下载文件；返回整数。0:成功；1:文件存在;-1:下载出错
* @return
*/
private int downFile(){
InputStream in=null;
try {
if(comparFile(dirName+File.separator+fileName)){
return 1;
}else{
in=getInputStream(urlStr);
writeFile(in);
}
} catch (Exception e) {
e.printStackTrace();
return -1;
}finally{
if(null != in){
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return 0;
}
/**
* 写出下载的文件到SD卡
* @param in
* @return
* @throws Exception
*/
private File writeFile(InputStream in)throws Exception{
File file=null;
OutputStream out=null;
try {
createDir(dirName);
file=createFile(fileName);
out=new FileOutputStream(file);
byte[] array=new byte[4*1024];
int len=0;
while (-1 !=(len=in.read(array))) {
out.write(array, 0, len);
}
out.flush();
} catch (Exception e) {
e.printStackTrace();
}finally{
if(null !=out){
out.close();
}
}
return file;
}
//创建下载的文件
private File createFile(String fileName)throws Exception {
File file=new File(path+dirName+File.separator+fileName);
file.createNewFile();
return file;
}
//创建文件夹
private File createDir(String dirName) {
File dir=new File(path+dirName);
if(!dir.exists() && !dir.isDirectory()){
dir.mkdir();
}
return dir;
}
//判断文件是否存在
private boolean comparFile(String filePath){
File file=new File(path+filePath);
return file.exists();
}
//通过下载地址得到输入流
private InputStream getInputStream(String urlStr)throws Exception {
url=new URL(urlStr);
HttpURLConnection connection=(HttpURLConnection) url.openConnection();
return connection.getInputStream();
}
}
布局文件之主页面：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".MainActivity" > <TextView android:id="@+id/text1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/text1" /> <EditText android:id="@+id/name" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="@android:drawable/editbox_background" android:layout_below="@id/text1" /> <TextView android:id="@+id/text2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/text2" android:layout_below="@id/name" /> <EditText android:id="@+id/pwd" android:layout_width="fill_parent" android:layout_height="wrap_content" android:password="true" android:background="@android:drawable/editbox_background" android:layout_below="@id/text2" /> <Button android:id="@+id/clear" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="@string/clear" android:layout_below="@id/pwd" android:layout_alignRight="@id/pwd" /> <Button android:id="@+id/ok" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="@string/ok" android:layout_below="@id/pwd" android:layout_toLeftOf="@id/clear" /> </RelativeLayout>
显示的第二页面：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".MainActivity" > <TextView android:id="@+id/user" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <LinearLayout android:id="@+id/lay1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/user" android:orientation="horizontal" > <CheckBox android:id="@+id/box1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/box1" /> <CheckBox android:id="@+id/box2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/box2" /> <CheckBox android:id="@+id/box3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/box3" /> </LinearLayout> <LinearLayout android:id="@+id/lay2" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:layout_below="@id/lay1" > <RadioGroup android:id="@+id/grop" android:layout_width="wrap_content" android:layout_height="wrap_content" > <RadioButton android:id="@+id/radio1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/raido1" /> <RadioButton android:id="@+id/radio2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/raido2" android:layout_marginLeft="120px" android:layout_marginTop="-36px" /> </RadioGroup> </LinearLayout> <Button android:id="@+id/load" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/load" android:layout_below="@id/lay2" android:layout_centerHorizontal="true" /> </RelativeLayout>
最后是常量：
<?xml version="1.0" encoding="utf-8"?> <resources> <string name="app_name">allpor</string> <string name="action_settings">Settings</string> <string name="text1">请输入姓名:</string> <string name="text2">请输入密码:</string> <string name="ok">登录</string> <string name="clear">重置</string> <string name="success">登录成功</string> <string name="down">登录失败</string> <string name="box1">青花瓷</string> <string name="box2">牛仔很忙</string> <string name="box3">甜甜的</string> <string name="raido1">普通</string> <string name="raido2">高质量</string> <string name="load">下载全部</string> </resources>