无废话Android之android下junit测试框架配置、保存文件到手机内存、android下文件访问的权限、保存文件到SD卡、获取SD卡大小、使用SharedPreferences进行数据存储、使用Pull解析器操作XML文件、android下操作sqlite数据库和事务（2）

1.android下junit测试框架配置
单元测试需要在手机中进行安装测试
(1).在清单文件中manifest节点下配置如下节点
 <instrumentation
  android:name="android.test.InstrumentationTestRunner"
  android:targetPackage="com.example.demo1" />
上面targetPackage指定的包要和应用的package相同。
(2)在清单文件中application节点下配置如下节点
<uses-library 
 android:name="android.test.runner"/>
(3).编写业务逻辑类
package com.example.demo1.service;

public class UserService {
    public int add(int x, int y) {
        return x + y;
    }
}
(4).编写单元测试类，该类继承 AndroidTestCase 
package com.example.demo1.test;

import com.example.demo1.service.UserService;

import android.test.AndroidTestCase;

public class TestUserService extends AndroidTestCase {
    public void testAdd() throws Exception {
        UserService us = new UserService();
        int result = us.add(3, 5);
        assertEquals(8, result);
    }
}
选择要测试的方法，右键点击“Run As”--“Android Junit Test” 

2.保存文件到手机内存
<?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" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="请输入用户名" />

    <EditText
        android:id="@+id/et_username"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <requestFocus />
    </EditText>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="请输入密码" />


    <EditText
        android:id="@+id/et_password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="textPassword" />

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <CheckBox
            android:id="@+id/cb_remember_psw"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:checked="true"
            android:text="记住密码" />

        <Button
            android:onClick="login"
            android:layout_alignParentRight="true"
            android:id="@+id/login"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="登录" />
    </RelativeLayout>

</LinearLayout>

package com.example.demo1;

import java.util.HashMap;

import com.example.demo1.service.LoginService;

import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;

public class LoginUIActivity extends Activity {
    private EditText et_username = null;
    private EditText et_password = null;
    private CheckBox cb_remeber_password = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login_ui);
        this.et_username = (EditText) this.findViewById(R.id.et_username);
        this.et_password = (EditText) this.findViewById(R.id.et_password);
        this.cb_remeber_password = (CheckBox) this.findViewById(R.id.cb_remember_psw);
        HashMap<String, String> info = LoginService.getInfo(this);
        if (info != null) {
            this.et_username.setText(info.get("username"));
            this.et_password.setText(info.get("password"));
        }
    }

    public void login(View view) {
        String username = this.et_username.getText().toString().trim();
        String password = this.et_password.getText().toString().trim();
        if (TextUtils.isEmpty(username) || TextUtils.isEmpty(password)) {
            Toast.makeText(this, "用户名或密码不能为空", 0).show();
        } else {
            if (this.cb_remeber_password.isChecked()) {
                boolean result = LoginService.saveInfo(this, username, password);
                if (result) {
                    Toast.makeText(this, "保存密码成功", 0).show();
                }
            }
            if ("weijie".equals(username) && "123".equals(password)) {
                Toast.makeText(this, "登录成功", 0).show();
            } else {
                Toast.makeText(this, "登录失败", 0).show();

            }
        }
    }
}


package com.example.demo1.service;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.util.HashMap;

import android.content.Context;
import android.widget.Toast;

public class LoginService {

    public static boolean saveInfo(Context context, String username,
            String password) {
        // getFileDir : /data/data/包名/files
        // getCacheDir : /data/data/包名/cache
        File file = new File(context.getFilesDir(), "info.txt");
        try {
            FileOutputStream fos = new FileOutputStream(file);
            fos.write((username + "=" + password).getBytes());
            fos.flush();
            fos.close();
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public static HashMap<String, String> getInfo(Context context) {
        File file = new File(context.getFilesDir(), "info.txt");

        try {
            if (file.exists()) {
                FileInputStream fis = new FileInputStream(file);
                BufferedReader br = new BufferedReader(new InputStreamReader(fis));
                String[] result = br.readLine().split("=");
                HashMap<String, String> map = new HashMap<String, String>();
                map.put("username", result[0]);
                map.put("password", result[1]);
                br.close();
                return map;
            }
        } catch (Exception e) {
            Toast.makeText(context, "无法读取用户信息", 0).show();

        }
        return null;
    }
}

3.android下文件访问的权限
利用Context提供的参数，我们可以设置文件不同访问权限
Context.MODE_PRIVATE：为默认操作模式，代表该文件是私有数据，只能被应用本身访问，在该模式下，写入的内容会覆盖原文件的内容，如果想把新写入的内容追加到原文件中。可以使用Context.MODE_APPEND
Context.MODE_APPEND：模式会检查文件是否存在，存在就往文件追加内容，否则就创建新文件。
Context.MODE_WORLD_READABLE和Context.MODE_WORLD_WRITEABLE用来控制其他应用是否有权限读写该文件。
MODE_WORLD_READABLE：表示当前文件可以被其他应用读取；MODE_WORLD_WRITEABLE：表示当前文件可以被其他应用写入。
如果希望文件被其他应用读和写，可以传入： 
openFileOutput("info.txt", Context.MODE_WORLD_READABLE + Context.MODE_WORLD_WRITEABLE);


4.保存文件到SD卡
package com.example.demo1.service;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.util.HashMap;

import android.content.Context;
import android.os.Environment;
import android.widget.Toast;

public class LoginService1 {

    public static boolean saveInfo(Context context, String username,
            String password) {

        try {
            if (Environment.MEDIA_MOUNTED.equals(Environment
                    .getExternalStorageState())) {
                File file = new File(Environment.getExternalStorageDirectory(),
                        "info.txt");
                FileOutputStream fos = new FileOutputStream(file);
                fos.write((username + "=" + password).getBytes());
                fos.flush();
                fos.close();
                return true;
            } else {
                Toast.makeText(context, "cdcard被卸载", 0).show();
                return false;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public static HashMap<String, String> getInfo(Context context) {
        File file = new File(Environment.getExternalStorageDirectory(),
                "info.txt");
        try {
            FileInputStream fis = new FileInputStream(file);
            BufferedReader br = new BufferedReader(new InputStreamReader(fis));
            String[] result = br.readLine().split("=");
            HashMap<String, String> map = new HashMap<String, String>();
            map.put("username", result[0]);
            map.put("password", result[1]);
            br.close();
            return map;

        } catch (Exception e) {
            Toast.makeText(context, "无法读取用户信息", 0).show();

        }
        return null;
    }
}

 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

5.分析setting源代码获取SD卡大小
public String getSdcardInfo() {
        File path = Environment.getExternalStorageDirectory();
        StatFs stat = new StatFs(path.getPath());
        long blockSize = stat.getBlockSize();
        long totalBlocks = stat.getBlockCount();
        long availableBlocks = stat.getAvailableBlocks();

        long totalSize = blockSize * totalBlocks;
        long availSize = blockSize * availableBlocks;

        String totalStr = Formatter.formatFileSize(LoginUIActivity.this,
                totalSize);
        String availStr = Formatter.formatFileSize(LoginUIActivity.this,
                availSize);
        return "cdcard总内存：" + totalStr + "\n" + "可用内存：" + availStr;

    }

    public String getROMInfo() {
        File path = Environment.getDataDirectory();
        StatFs stat = new StatFs(path.getPath());
        long blockSize = stat.getBlockSize();
        long totalBlocks = stat.getBlockCount();
        long availableBlocks = stat.getAvailableBlocks();
        long totalSize = blockSize * totalBlocks;
        long availSize = blockSize * availableBlocks;

        String totalStr = Formatter.formatFileSize(LoginUIActivity.this,
                totalSize);
        String availStr = Formatter.formatFileSize(LoginUIActivity.this,
                availSize);
        return "手机总内存：" + totalStr + "\n" + "可用内存：" + availStr;

    }
    
6.使用SharedPreferences进行数据存储
(1)保存信息,会生成config.xml文件，一般用来保存配置信息的
SharedPreferences sp = context.getSharedPreferences("config", Context.MODE_PRIVATE);
Editor editor = sp.edit();
editor.putString("username", username);
editor.putString("password", password);
editor.commit();
(2)获取信息
SharedPreferences sp = context.getSharedPreferences("config", Context.MODE_PRIVATE);
sp.getString("username", "");
sp.getString("password", "");

7.使用Pull解析器生成XML文件
public void save(View view) {
        XmlSerializer xmlSerializer = Xml.newSerializer();
        File file = new File(Environment.getExternalStorageDirectory(),
                "config.xml");
        try {
            FileOutputStream fos = new FileOutputStream(file);
            xmlSerializer.setOutput(fos, "utf-8");
            xmlSerializer.startDocument("utf-8", true);

            xmlSerializer.startTag(null, "smss");

            for (SmsInfo info : infos) {
                xmlSerializer.startTag(null, "sms");
                xmlSerializer.attribute(null, "id", info.getId() + "");

                xmlSerializer.startTag(null, "date");
                xmlSerializer.text(info.getDate() + "");
                xmlSerializer.endTag(null, "date");

                xmlSerializer.startTag(null, "address");
                xmlSerializer.text(info.getAddress());
                xmlSerializer.endTag(null, "address");

                xmlSerializer.startTag(null, "body");
                xmlSerializer.text(info.getBody());
                xmlSerializer.endTag(null, "body");
                xmlSerializer.endTag(null, "sms");
            }
            xmlSerializer.endTag(null, "smss");

            xmlSerializer.endDocument();
            fos.close();
            Toast.makeText(this, "保存成功", 0).show();

        } catch (Exception e) {
            e.printStackTrace();
            Toast.makeText(this, "保存失败", 0).show();
        }
    }

8.采用pull解析器解析xml文件
(1).准备一个xml文件，将其拷贝到工程的src目录下
<?xml version="1.0" encoding="utf-8"?>
<infos>
<city id="1">
<temp>20‘C/30‘C</temp>
<weather>多云</weather>
<wind>南风3级</wind>
<name>上海</name>
<pm>200</pm>
</city>

<city id="2">
<temp>20‘C/35‘C</temp>
<weather>暴雨</weather>
<wind>南风10级</wind>
<name>北京</name>
<pm>800</pm>
</city>

<city id="3">
<temp>0‘C/10‘C</temp>
<weather>暴雪</weather>
<wind>北风32级</wind>
<name>广州</name>
<pm>200</pm>
</city>

</infos>
(2)
public static ArrayList<WeatherInfo> getWeatherInfo(InputStream is)
throws Exception {
ArrayList<WeatherInfo> infos = null;
WeatherInfo info = null;

// XmlPullParser parser = Xml.newPullParser();

XmlPullParserFactory fac = XmlPullParserFactory.newInstance();
XmlPullParser parser = fac.newPullParser();

parser.setInput(is, "utf-8");
int type = parser.getEventType();
while (type != XmlPullParser.END_DOCUMENT) {
switch (type) {
case XmlPullParser.START_TAG:
if ("infos".equals(parser.getName())) {
infos = new ArrayList<WeatherInfo>();
} else if ("city".equals(parser.getName())) {
info = new WeatherInfo();
info.setId(Integer.parseInt(parser.getAttributeValue(0)));
} else if ("temp".equals(parser.getName())) {
info.setTemp(parser.nextText());
} else if ("weather".equals(parser.getName())) {
info.setWeather(parser.nextText());
} else if ("wind".equals(parser.getName())) {
info.setWind(parser.nextText());
} else if ("name".equals(parser.getName())) {
info.setName(parser.nextText());
} else if ("pm".equals(parser.getName())) {
info.setPm(parser.nextText());
}
break;

case XmlPullParser.END_TAG:
if ("city".equals(parser.getName())) {
infos.add(info);
info = null;
}
break;
}
type = parser.next();
}
return infos;

}

(3).调用
public class WeatherActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TextView tv_info = (TextView) this.findViewById(R.id.vt_info);

try {
ArrayList<WeatherInfo> infos = WeaterService
.getWeatherInfo(WeatherActivity.class.getClassLoader()
.getResourceAsStream("weather.xml"));
StringBuffer sb = new StringBuffer();
for (WeatherInfo info : infos) {
sb.append(info);
sb.append("\n");
}
tv_info.setText(sb.toString());
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(this, "xml解析失败", 0).show();
}

}
}

9.android下创建一个sqlite数据库
public class PersonSQLiteOpenHelper extends SQLiteOpenHelper {
private static final String DBFILENAME = "person.db";
private static int db_version = 2;

public PersonSQLiteOpenHelper(Context context) {
super(context, DBFILENAME, null, db_version);
}

/**
* 当数据库第一次创建时调用
*/
@Override
public void onCreate(SQLiteDatabase db) {
String sql = "create table person(id integer primary key autoincrement,name varchar(20),number varchar(20))";
db.execSQL(sql);
}

/**
* 当数据库的版本号发生增加的时候调用
*/
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
System.out.println("数据库更改！");
String sql = "alter table person add account varchar(20)";
db.execSQL(sql);
}

}

10.sql语句实现数据库的增删改查
(1)添加条目
public void add(String name, String number) {
SQLiteDatabase db = this.helper.getWritableDatabase();
db.execSQL("insert into person(name,number) values(?,?)", new Object[] {
name, number });
db.close();
}

(2).查找条目是否存在
public boolean find(String name) {
SQLiteDatabase db = this.helper.getReadableDatabase();
Cursor cursor = db.rawQuery("select * from person where name=?",
new String[] { name });
boolean result = cursor.moveToNext();
cursor.close();
db.close();
return result;
}

(3).更新条目
public void update(String name, String newNumber) {
SQLiteDatabase db = this.helper.getWritableDatabase();
db.execSQL("update person set number=? where name=?", new Object[] {
newNumber, name });
db.close();
}

(4).删除条目
public void delete(String name) {
SQLiteDatabase db = this.helper.getWritableDatabase();
db.execSQL("delete from person where name=?", new Object[] { name });
db.close();
}

(5).查找所有条目
public ArrayList<Person> findAll() {
SQLiteDatabase db = this.helper.getReadableDatabase();
ArrayList<Person> persons = new ArrayList<Person>();
Cursor cursor = db.rawQuery("select * from person", null);
while (cursor.moveToNext()) {
int id = cursor.getInt(cursor.getColumnIndex("id"));
String name = cursor.getString(cursor.getColumnIndex("name"));
String number = cursor.getString(cursor.getColumnIndex("number"));
Person p = new Person(id, name, number);
persons.add(p);
}
cursor.close();
db.close();
return persons;
}

11.系统api实现数据库的增删改查&sqlite3工具的使用
(1).添加条目
public long add(String name, String number) {
SQLiteDatabase db = this.helper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("name", name);
values.put("number", number);
long id = db.insert("person", null, values);
db.close();
return id;
}

(2).查找条目是否存在
public boolean find(String name) {
SQLiteDatabase db = this.helper.getReadableDatabase();
Cursor cursor = db.query("person", null, "name=?",
new String[] { name }, null, null, null);
boolean result = cursor.moveToNext();
cursor.close();
db.close();
return result;
}

(3).更新条目
public int update(String name, String newNumber) {
SQLiteDatabase db = this.helper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("number", newNumber);
int number = db.update("person", values, "name=?",
new String[] { name });
db.close();
return number;
}

(4).删除条目
public int delete(String name) {
SQLiteDatabase db = this.helper.getWritableDatabase();
// db.execSQL("delete from person where name=?", new Object[] { name });
int number = db.delete("person", "name=?", new String[] { name });
db.close();
return number;
}

(5).查找所有条目
public ArrayList<Person> findAll() {
SQLiteDatabase db = this.helper.getReadableDatabase();
ArrayList<Person> persons = new ArrayList<Person>();
Cursor cursor = db.query("person", null, null, null, null, null, null);
while (cursor.moveToNext()) {
int id = cursor.getInt(cursor.getColumnIndex("id"));
String name = cursor.getString(cursor.getColumnIndex("name"));
String number = cursor.getString(cursor.getColumnIndex("number"));
Person p = new Person(id, name, number);
persons.add(p);
}
cursor.close();
db.close();
return persons;

}


12.使用事务操作SQLite数据库
SQLiteDatabase db =  this.helper.getReadableDatabase();
db.beginTransaction();//开始事务
try {
    db.execSQL("insert into person(name, age) values(?,?)", new Object[]{"张三", 4});
    db.execSQL("update person set name=? where personid=?", new Object[]{"李四", 1});
    db.setTransactionSuccessful();//调用此方法会在执行到endTransaction() 时提交当前事务，如果不调用此方法会回滚事务
} finally {
    db.endTransaction();//由事务的标志决定是提交事务，还是回滚事务
} 
db.close();