使用ContentProvider管理App数据

文章目录

1. 1. 工具类
2. 2. 数据库操作类

工具类

• Column
  用于管理字段

  public class Column {
  	// 约束
  	public static enum Constraint {
  		UNIQUE("UNIQUE"), NOT("NOT"), NULL("NULL"), CHECK("CHECK"), FOREIGN_KEY(
  				"FOREIGN KEY"), PRIMARY_KYE("PRIMARY KEY");
  		private String value;
  
  		private Constraint(String value) {
  			this.value = value;
  		}
  
  		@Override
  		public String toString() {
  			return value;
  		}
  	}
  
  	// 数据类型
  	public static enum DataType {
  		NULL, INTEGER, REAL, TEXT, BLOB
  	}
  
  	private String mColumnName;
  	private Constraint mConstraint;
  	private DataType mDataType;
  
  	public Column(String columnName, Constraint constraint, DataType dataType) {
  		mColumnName = columnName;
  		mConstraint = constraint;
  		mDataType = dataType;
  	}
  
  	public String getColumnName() {
  		return mColumnName;
  	}
  
  	public Constraint getConstraint() {
  		return mConstraint;
  	}
  
  	public DataType getDataType() {
  		return mDataType;
  	}
  }

• SQLiteTable
  用于表管理

  public class SQLiteTable {
  	String mTableName;
  	ArrayList<Column> mColumnsDefinitions = new ArrayList<Column>();
  
  	public String getTableName() {
  		return mTableName;
  	}
  
  	// 自动添加主键_ID
  	public SQLiteTable(String tableName) {
  		mTableName = tableName;
  		mColumnsDefinitions.add(new Column(BaseColumns._ID,
  				Column.Constraint.PRIMARY_KYE, Column.DataType.INTEGER));
  	}
  
  	public SQLiteTable addColumn(Column columnsDefinition) {
  		mColumnsDefinitions.add(columnsDefinition);
  		return this;
  	}
  
  	public SQLiteTable addColumn(String columnName, Column.DataType dataType) {
  		mColumnsDefinitions.add(new Column(columnName, null, dataType));
  		return this;
  	}
  
  	public SQLiteTable addColumn(String columnName,
  			Column.Constraint constraint, Column.DataType dataType) {
  		mColumnsDefinitions.add(new Column(columnName, constraint, dataType));
  		return this;
  	}
  
  	// 在SQLite中创建本表
  	public void create(SQLiteDatabase db) {
  		String formatter = " %s";
  		StringBuilder stringBuilder = new StringBuilder();
  		stringBuilder.append("CREATE TABLE IF NOT EXISTS ");
  		stringBuilder.append(mTableName);
  		stringBuilder.append("(");
  		int columnCount = mColumnsDefinitions.size();
  		int index = 0;
  		for (Column columnsDefinition : mColumnsDefinitions) {
  			stringBuilder.append(columnsDefinition.getColumnName()).append(
  					String.format(formatter, columnsDefinition.getDataType()
  							.name()));
  			Column.Constraint constraint = columnsDefinition.getConstraint();
  
  			if (constraint != null) {
  				stringBuilder.append(String.format(formatter,
  						constraint.toString()));
  			}
  			if (index < columnCount - 1) {
  				stringBuilder.append(",");
  			}
  			index++;
  		}
  		stringBuilder.append(");");
  		db.execSQL(stringBuilder.toString());
  	}
  
  	// 在SQLite中删除本表
  	public void delete(final SQLiteDatabase db) {
  		db.execSQL("DROP TABLE IF EXISTS " + mTableName);
  	}
  }

数据库操作类

public abstract class BaseDataHelper {
	private Context mContext;

	public BaseDataHelper(Context context) {
		mContext = context;
	}

	public Context getContext() {
		return mContext;
	}

	protected abstract Uri getContentUri();

	public void notifyChange() {
		mContext.getContentResolver().notifyChange(getContentUri(), null);
	}

	protected final Cursor query(Uri uri, String[] projection,
			String selection, String[] selectionArgs, String sortOrder) {
		return mContext.getContentResolver().query(uri, projection, selection,
				selectionArgs, sortOrder);
	}

	protected final Cursor query(String[] projection, String selection,
			String[] selectionArgs, String sortOrder) {
		return mContext.getContentResolver().query(getContentUri(), projection,
				selection, selectionArgs, sortOrder);
	}

	protected final Uri insert(ContentValues values) {
		return mContext.getContentResolver().insert(getContentUri(), values);
	}

	protected final int bulkInsert(ContentValues[] values) {
		return mContext.getContentResolver()
				.bulkInsert(getContentUri(), values);
	}

	protected final int update(ContentValues values, String where,
			String[] whereArgs) {
		return mContext.getContentResolver().update(getContentUri(), values,
				where, whereArgs);
	}

	protected final int delete(Uri uri, String selection, String[] selectionArgs) {
		return mContext.getContentResolver().delete(getContentUri(), selection,
				selectionArgs);
	}

	protected final Cursor getList(String[] projection, String selection,
			String[] selectionArgs, String sortOrder) {
		return mContext.getContentResolver().query(getContentUri(), projection,
				selection, selectionArgs, sortOrder);
	}

	public CursorLoader getCursorLoader(Context context) {
		return getCursorLoader(context, null, null, null, null);
	}

	protected final CursorLoader getCursorLoader(Context context,
			String[] projection, String selection, String[] selectionArgs,
			String sortOrder) {
		return new CursorLoader(context, getContentUri(), projection,
				selection, selectionArgs, sortOrder);
	}
}