execute Database Query by Class via reflection - Android Database

Android examples for Database:SQL Query

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Description

execute Database Query by Class via reflection

Demo Code


//package com.book2s;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

public class Main {
    public static List<Object> executeQuery(Context context, String sql,
            Class clz) {/*from  w  w w .j a  va 2 s.  c o  m*/
        try {
            List<Object> result = new ArrayList<Object>();
            SQLiteDatabase db = context.openOrCreateDatabase("data.db",
                    context.MODE_PRIVATE, null);
            Cursor cursor = db.rawQuery(sql, new String[] {});
            Method method = clz.getMethod("generateEntity", Map.class);
            while (cursor.moveToNext()) {
                Map<String, Object> row = new HashMap<String, Object>();

                for (String item : cursor.getColumnNames()) {
                    int type = cursor.getType(cursor.getColumnIndex(item));
                    switch (type) {
                    case Cursor.FIELD_TYPE_STRING:
                        row.put(item, cursor.getString(cursor
                                .getColumnIndex(item)));
                        break;
                    case Cursor.FIELD_TYPE_INTEGER:
                        row.put(item,
                                cursor.getInt(cursor.getColumnIndex(item)));
                        break;
                    case Cursor.FIELD_TYPE_NULL:
                        row.put(item, null);
                        break;
                    }
                }
                result.add(method.invoke(null, row));
            }
            cursor.close();
            db.close();
            return result;
        } catch (Exception ex) {
            ex.printStackTrace();
            return null;
        }
    }
}

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