Android SQLite数据结合ContentProvider实现数据的一个增删改查操作

系统管理员 2022-04-22 00:18 133阅读 0赞

\#Android SQLite数据结合ContentProvider实现数据的一个增删改查操作  
使用ContentProvider控制数据库，可以实现程序本身数据的增删改查，也可让别的程序对本程序的数据库进行增删改查操作，只需要在AndroidManifest中改属性exported，是true还是false就可以了。

本文也提供一个示例程序，这个示例程序是一个新项目中需要用到的，并且封装比较好，逻辑清晰，对于后期添加多个数据库表格管理起来很方便。

效果图：

![1][]

该示例没有输入操作，简单实现了增删改查操作，具体的实现和控制看代码即可。  
\#\#\#1、DBOpenHelper类

package com.liwenzhi.asr.sqlitedemo.provider;
    
    import android.content.Context;
    import android.database.sqlite.SQLiteDatabase;
    import android.database.sqlite.SQLiteOpenHelper;
    
    import com.liwenzhi.asr.sqlitedemo.table.PeopleInfoTable;
    import com.liwenzhi.asr.sqlitedemo.util.LogUtil;
    
    //控制数据库的创建和删除的类
    public class DBOpenHelper extends SQLiteOpenHelper {
    
        //这里数据库路径是默认的路径，如果需要也是可以放在SD卡下的，只需要将下面的数据库名称改为“sdcard/demo/file.db”
    	//但是要注意，如果存储在sd卡下是需要手机的读取权限的，如果放在包名下是不需要手机读写权限的
        private static final String DATABASE_NAME = "file.db"; //默认路径（/data/data/package/...）+数据库名称
        private static final int DATABASE_VERSION = 1;//数据库版本
        private final String TAG = "DBOpenHelper";
    
    
        public DBOpenHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
            LogUtil.i(TAG, "DBOpenHelper：DATABASE_NAME=" + DATABASE_NAME + ",DATABASE_VERSION=" + DATABASE_VERSION);
        }
    
        @Override
        public void onCreate(SQLiteDatabase db) {
            LogUtil.i(TAG, "DBOpenHelper onCreate");
            db.execSQL(PeopleInfoTable.CREATE_PEOPLE_INFO_TABLE);
        }
    
        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            LogUtil.e(TAG, "DBOpenHelper onUpgrade:oldVersion=" + oldVersion + ",newVersion=" + newVersion);
            db.execSQL("DROP TABLE IF EXISTS " + PeopleInfoTable.TABLE_NAME);  //删除表格
            onCreate(db);   //重新创建表格
        }
    
    }

\#\#\#2、SqliteProvider类

package com.liwenzhi.asr.sqlitedemo.provider;
    
    import android.content.ContentProvider;
    import android.content.ContentUris;
    import android.content.ContentValues;
    import android.content.UriMatcher;
    import android.database.Cursor;
    import android.database.SQLException;
    import android.database.sqlite.SQLiteDatabase;
    import android.net.Uri;
    import android.util.Log;
    
    import com.liwenzhi.asr.sqlitedemo.table.PeopleInfoTable;
    import com.liwenzhi.asr.sqlitedemo.util.LogUtil;
    
    //真正实现控制数据库增删改查的代码类
    public class SqliteProvider extends ContentProvider {
        private DBOpenHelper dbOpenHelper;
        private static final UriMatcher MATCHER;
    
        private String TAG = "SqliteProvider-->";
        private final Object mLock = new Object();
    
        //Uri info
        //authority
        public static final String PEOPLE_INFO_AUTHORITY = "com.demo.FileProvider";
        public static final Uri AUTHORITY_URI = Uri.parse("content://" + PEOPLE_INFO_AUTHORITY);
        //code
        private static final int PEOPLE_INFO_CODE = 1;
    
        static {
            MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
            MATCHER.addURI(PEOPLE_INFO_AUTHORITY, PeopleInfoTable.TABLE_NAME, PEOPLE_INFO_CODE);
        }
    
        @Override
        public boolean onCreate() {
            Log.d(TAG, " onCreate ");
            this.dbOpenHelper = new DBOpenHelper(this.getContext());
            return true;
        }
    
        @Override
        public String getType(Uri uri) {
            return null;
        }
    
        /**
         * 查询数据库的数据
         *
         * @param uri
         * @param projection
         * @param selection
         * @param selectionArgs
         * @param sortOrder
         * @return
         */
        @Override
        public Cursor query(Uri uri, String[] projection, String selection,
                            String[] selectionArgs, String sortOrder) {
            Log.d(TAG, " query ");
            try {
                synchronized (mLock) {
                    SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
                    switch (MATCHER.match(uri)) {
                        case PEOPLE_INFO_CODE:
                            return db.query(PeopleInfoTable.TABLE_NAME, projection, selection, selectionArgs,
                                    null, null, sortOrder);
                        default:
                            throw new IllegalArgumentException("Unkwon Uri:" + uri.toString());
                    }
                }
            } catch (SQLException e) {
                LogUtil.e(TAG, "query error:" + e.getMessage());
                return null;
            }
    
        }
    
    
        /**
         * 插入数据
         *
         * @param uri
         * @param values
         * @return
         */
        @Override
        public Uri insert(Uri uri, ContentValues values) {
            Log.d(TAG, " insert ");
            SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
            switch (MATCHER.match(uri)) {
                case PEOPLE_INFO_CODE:
                    // 特别说一下第二个参数是当name字段为空时，将自动插入一个NULL。
                    long rowid = db.insert(PeopleInfoTable.TABLE_NAME, null, values);
                    Uri insertUri = ContentUris.withAppendedId(uri, rowid);// 得到代表新增记录的Uri
                    this.getContext().getContentResolver().notifyChange(uri, null);
                    return insertUri;
    
                default:
                    throw new IllegalArgumentException("Unkwon Uri:" + uri.toString());
            }
        }
    
        /**
         * 删除数据
         *
         * @param uri
         * @param selection
         * @param selectionArgs
         * @return
         */
        @Override
        public int delete(Uri uri, String selection, String[] selectionArgs) {
            SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
            int count = 0;
            switch (MATCHER.match(uri)) {
                case PEOPLE_INFO_CODE:
                    count = db.delete(PeopleInfoTable.TABLE_NAME, selection, selectionArgs);
                    return count;
    
                default:
                    throw new IllegalArgumentException("Unkwon Uri:" + uri.toString());
            }
        }
    
        /**
         * 修改数据
         *
         * @param uri
         * @param values
         * @param selection
         * @param selectionArgs
         * @return
         */
        @Override
        public int update(Uri uri, ContentValues values, String selection,
                          String[] selectionArgs) {
            SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
            int count = 0;
            switch (MATCHER.match(uri)) {
                case PEOPLE_INFO_CODE:
                    count = db.update(PeopleInfoTable.TABLE_NAME, values, selection, selectionArgs);
                    return count;
                default:
                    throw new IllegalArgumentException("Unkwon Uri:" + uri.toString());
            }
        }
    
    }

\#\#\#3、PeopleInfo类

package com.liwenzhi.asr.sqlitedemo.bean;
    
    /**
     * 人物信息
     */
    
    public class PeopleInfo {
        private int id;
        private String name;
        private int age;
        private int height;
        private float weight;
        private String remark;
    
        public PeopleInfo() {
        }
    
        public PeopleInfo(String name, int age, int height, float weight, String remark) {
            this.name = name;
            this.age = age;
            this.height = height;
            this.weight = weight;
            this.remark = remark;
        }
    
        public PeopleInfo(int id, String name, int age, int height, float weight, String remark) {
            this.id = id;
            this.name = name;
            this.age = age;
            this.height = height;
            this.weight = weight;
            this.remark = remark;
        }
    
        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 int getAge() {
            return age;
        }
    
        public void setAge(int age) {
            this.age = age;
        }
    
        public int getHeight() {
            return height;
        }
    
        public void setHeight(int height) {
            this.height = height;
        }
    
        public float getWeight() {
            return weight;
        }
    
        public void setWeight(float weight) {
            this.weight = weight;
        }
    
        public String getRemark() {
            return remark;
        }
    
        public void setRemark(String remark) {
            this.remark = remark;
        }
    
        @Override
        public String toString() {
            return "PeopleInfo{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    ", age=" + age +
                    ", height=" + height +
                    ", weight=" + weight +
                    ", remark='" + remark + '\'' +
                    '}';
        }
    }

\#\#\#4、PeopleInfoTable类

package com.liwenzhi.asr.sqlitedemo.table;
    
    import android.content.ContentValues;
    import android.database.Cursor;
    import android.net.Uri;
    
    import com.liwenzhi.asr.sqlitedemo.bean.PeopleInfo;
    import com.liwenzhi.asr.sqlitedemo.provider.SqliteProvider;
    
    
    /**
     * 管理单个表格的类，
     *定义了对应的字符串
     *创建表格的语句
     *设置对象和获取对象的语句
     */
    
    public class PeopleInfoTable {
    
        //表名称
        public static final String TABLE_NAME = "filePath";
    
        //表格的基本信息的字符串
        public static final String ID = "_id";
        public static final String NAME = "name";
        public static final String AGE = "age";
        public static final String HEIGHT = "height";
        public static final String WEIGHT = "weight";
        public static final String REMARK = "remark";
    
        //创建个人信息表格的字符串命令 ，四个属性自增主键id，姓名，年龄，身高，体重，备注
        public static final String CREATE_PEOPLE_INFO_TABLE = "CREATE TABLE " + TABLE_NAME +
                " (" + ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + NAME + " TEXT," + AGE + " INTEGER,  " + HEIGHT + " INTEGER, " +
                WEIGHT + " FLOAT, " + REMARK + " TEXT)";
    
        //需要进行操作的uri对象
        private static final Uri CONTENT_URI = Uri.withAppendedPath(SqliteProvider.AUTHORITY_URI, TABLE_NAME);
    
        //返回PeopleInfo表格操作的uri地址对象
        public static Uri getContentUri() {
            return CONTENT_URI;
        }
    
        public static ContentValues putValues(PeopleInfo info) {
            ContentValues values = new ContentValues();
            values.put(NAME, info.getName());
            values.put(AGE, info.getAge());
            values.put(HEIGHT, info.getHeight());
            values.put(WEIGHT, info.getWeight());
            values.put(REMARK, info.getRemark());
            return values;
        }
    
        public static PeopleInfo getValues(Cursor cursor) {
            int id = cursor.getInt(cursor.getColumnIndex(ID));
            String name = cursor.getString(cursor.getColumnIndex(NAME));
            int age = cursor.getInt(cursor.getColumnIndex(AGE));
            int height = cursor.getInt(cursor.getColumnIndex(HEIGHT));
            float weight = cursor.getFloat(cursor.getColumnIndex(WEIGHT));
            String remark = cursor.getString(cursor.getColumnIndex(REMARK));
            PeopleInfo peopleInfo = new PeopleInfo(id, name, age, height, weight, remark);
            return peopleInfo;
        }
    
    }

\#\#\#5、DataManager类

package com.liwenzhi.asr.sqlitedemo.manager;
    
    import android.content.ContentResolver;
    import android.content.ContentValues;
    import android.content.Context;
    import android.database.Cursor;
    import android.net.Uri;
    
    import com.liwenzhi.asr.sqlitedemo.bean.PeopleInfo;
    import com.liwenzhi.asr.sqlitedemo.table.PeopleInfoTable;
    
    import java.util.ArrayList;
    import java.util.List;
    
    /**
     * 数据管理类
     *管理所有数据库表格的增删改查操作
     */
    
    public class DataManager {
        static final String TAG = "DataManager";
    
        public static void addPeople(Context context, PeopleInfo info) {
            ContentResolver contentResolver = context.getContentResolver();
            Uri uri = PeopleInfoTable.getContentUri();
            ContentValues values = PeopleInfoTable.putValues(info);
            contentResolver.insert(uri, values);
        }
    
        public static void updatePeople(Context context, String name, PeopleInfo info) {
            ContentResolver contentResolver = context.getContentResolver();
            Uri uri = PeopleInfoTable.getContentUri();
            ContentValues values = new ContentValues();
            values.put(PeopleInfoTable.AGE, info.getAge());
            values.put(PeopleInfoTable.HEIGHT, info.getHeight());
            values.put(PeopleInfoTable.WEIGHT, info.getWeight());
            values.put(PeopleInfoTable.REMARK, info.getRemark());
            values.put(PeopleInfoTable.NAME, info.getName());
            contentResolver.update(uri, values, PeopleInfoTable.NAME + "=?", new String[]{name});
        }
    
        public static void deletePeople(Context context, String name) {
            ContentResolver contentResolver = context.getContentResolver();
            Uri uri = PeopleInfoTable.getContentUri();
            contentResolver.delete(uri, PeopleInfoTable.NAME + "=?", new String[]{name});
        }
    
        public static PeopleInfo getOnePeople(Context context, String userName) {
            PeopleInfo peopleInfo = null;
            Uri uri = PeopleInfoTable.getContentUri();
            Cursor cursor = context.getContentResolver().query(uri, null, PeopleInfoTable.NAME + "=?", new String[]{userName}, null);
    
            if (cursor != null) {
                if (cursor.moveToNext()) {
                    peopleInfo = PeopleInfoTable.getValues(cursor);
                }
                cursor.close();
            }
            return peopleInfo;
        }
    
        public static List<PeopleInfo> getAllPeoples(Context context) {
            List<PeopleInfo> list = new ArrayList<>();
            Uri uri = PeopleInfoTable.getContentUri();
            Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
            if (cursor != null) {
                while (cursor.moveToNext()) {
                    PeopleInfo info = PeopleInfoTable.getValues(cursor);
                    list.add(info);
                }
                cursor.close();
            }
            return list;
        }
    }

\#\#\#6、MainActivity类

package com.liwenzhi.asr.sqlitedemo.activity;
    
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.ListView;
    import android.widget.Toast;
    
    import com.liwenzhi.asr.sqlitedemo.R;
    import com.liwenzhi.asr.sqlitedemo.adapter.PeopleInfoAdapter;
    import com.liwenzhi.asr.sqlitedemo.bean.PeopleInfo;
    import com.liwenzhi.asr.sqlitedemo.manager.DataManager;
    
    import java.util.ArrayList;
    import java.util.List;
    
    /**
     * 该示例是SQLite数据结合ContentProvider实现数据的一个增删改查操作的示例代码
     * 该示例的特点是代码清晰，扩展性好
     * 简单规范如下：
     * 1、数据库用到的数据类，放在bean包下
     * 2、每张数据的表格都在table下创建一个对应的类，并且定义该表格对应的字符串数据和设置ContentValues和获取类对象
     * 3、DataManager是控制所有数据进行增删改查操作的类，不管是一个数据的一个表格还是多个表格的数据操作
     * 4、SqliteProvider是实际的增删改查操作语句
     * 5、后面每次添加表格只要添加bean类、Table类、SqliteProvider中添加对应的过滤和操作，DataManager添加对应的控制代码就可以了
     */
    public class MainActivity extends AppCompatActivity {
    
    
        private ListView listView;
        private PeopleInfoAdapter adapter;
        private List<PeopleInfo> list = new ArrayList<>();
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            initView();
            initData();
        }
    
        private void initView() {
            listView = findViewById(R.id.listView);
        }
    
        private void initData() {
            adapter = new PeopleInfoAdapter(this, list);
            listView.setAdapter(adapter);
        }
    
        //增加数据
        public void insertData(View view) {
            PeopleInfo peopleInfo = new PeopleInfo("李文志", 18, 170, 61, "reamark:huawei");
            DataManager.addPeople(this, peopleInfo);
        }
    
        //删除数据
        public void deleteData(View view) {
            DataManager.deletePeople(this, "李文志");
        }
    
        //修改数据
        public void updateData(View view) {
            PeopleInfo peopleInfo = new PeopleInfo("李文志", 19, 170, 61, "reamark:huawei");
            DataManager.updatePeople(this, "李文志", peopleInfo);
        }
    
        //查询数据
        public void selectData(View view) {
            list.clear();
            List<PeopleInfo> peopleInfos = DataManager.getAllPeoples(this);
            list.addAll(peopleInfos);
            adapter.notifyDataSetChanged();
        }
    
        //查询单个数据
        public void selectOneData(View view) {
            PeopleInfo peopleInfo = DataManager.getOnePeople(this, "李文志");
            Toast.makeText(this, peopleInfo + "", Toast.LENGTH_SHORT).show();
    
        }
    
    
    }

\#\#\#\#运行上面代码，点击添加数据，在点击查询数据，显示：  
![2][]

\#\#\#\#点击查询单个数据：  
![3][]

代码如果需要可以下载查看：  
[https://download.csdn.net/download/wenzhi20102321/10756729][https_download.csdn.net_download_wenzhi20102321_10756729]  
适当修改代码，就可以用到项目中了。

\#共勉：态度决定人生的高度。

[1]: https://i.imgur.com/buqlmNp.png
[2]: https://i.imgur.com/RUNtCO7.png
[3]: https://i.imgur.com/DrpoxZx.png
[https_download.csdn.net_download_wenzhi20102321_10756729]: https://download.csdn.net/download/wenzhi20102321/10756729