How to Create Grade Report Using Content Providers in Android

Today In this Tutorial Learn How To Create Grade Report Using Content Providers in Android

1.MainActivity.java:

import android.app.Activity;

import android.content.ContentValues;

import android.database.Cursor;

import android.net.Uri;

import android.os.Bundle;

import android.view.Menu;

import android.view.View;

import android.widget.EditText;

import android.widget.Toast;

public class MainActivity extends Activity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

public void onClickAddRecord(View view) {

// Adding a new record

ContentValues values = new ContentValues();

values.put(ReportProvider.NAME,

((EditText) findViewById(R.id.CourseName)).getText().toString());

values.put(ReportProvider.GRADE,

((EditText) findViewById(R.id.txtGrade)).getText().toString());

Uri uri = getContentResolver().insert(ReportProvider.CONTENT_URI,

values);

Toast.makeText(getBaseContext(), uri.toString(), Toast.LENGTH_LONG)

.show();

}

public void onClickRetrieveRecords(View view) {

// Retrieve all records

String URL = "content://com.example.provider.Report/students";

Uri var = Uri.parse(URL);

Cursor c = managedQuery(var, null, null, null, "name");

if (c.moveToFirst()) {

do {

Toast.makeText(

this,

c.getString(c.getColumnIndex(ReportProvider._ID))

+ ", "

+ c.getString(c

.getColumnIndex(ReportProvider.NAME))

+ ", "

+ c.getString(c

.getColumnIndex(ReportProvider.GRADE)),

Toast.LENGTH_SHORT).show();

} while (c.moveToNext());

}

2.ReportProvider.java:

import java.util.HashMap;

import android.content.ContentProvider;

import android.content.ContentUris;

import android.content.ContentValues;

import android.content.Context;

import android.content.UriMatcher;

import android.database.Cursor;

import android.database.SQLException;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;

import android.database.sqlite.SQLiteQueryBuilder;

import android.net.Uri;

import android.text.TextUtils;

public class ReportProvider extends ContentProvider {

static final String PROVIDER_NAME = "com.example.provider.Report";

static final String URL = "content://" + PROVIDER_NAME + "/students";

static final Uri CONTENT_URI = Uri.parse(URL);

static final String _ID = "_id";

static final String NAME = "name";

static final String GRADE = "grade";

private static HashMap<String, String> PROJECTION_MAP;

static final int STUDENTS = 1;

static final int STUDENT_ID = 2;

static final UriMatcher uriMatcher;

static {

uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);

uriMatcher.addURI(PROVIDER_NAME, "students", STUDENTS);

uriMatcher.addURI(PROVIDER_NAME, "students/#", STUDENT_ID);

}

private SQLiteDatabase db;

static final String DATABASE_NAME = "College";

static final String TABLE_NAME = "students";

static final int DATABASE_VERSION = 1;

static final String CREATE_DB_TABLE = " CREATE TABLE "

+ TABLE_NAME + " (_id INTEGER PRIMARY KEY AUTOINCREMENT, "

+ " name TEXT NOT NULL, " + " grade TEXT NOT NULL);";

private static class DatabaseHelper extends SQLiteOpenHelper {

DatabaseHelper(Context context) {

super(context, DATABASE_NAME, null, DATABASE_VERSION);

}

@Override

public void onCreate(SQLiteDatabase db) {

db.execSQL(CREATE_DB_TABLE);

}

@Override

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);

onCreate(db);

}

@Override

public boolean onCreate() {

Context context = getContext();

DatabaseHelper dbHelper = new DatabaseHelper(context);

* Create a write-able database and would create it if the database

* dosen't exists already

db = dbHelper.getWritableDatabase();

return (db == null) ? false : true;

}

@Override

public Uri insert(Uri uri, ContentValues values) {

* Add a new student

long rowID = db.insert(TABLE_NAME, "", values);

* If record is added successfully

if (rowID > 0) {

Uri _uri = ContentUris.withAppendedId(CONTENT_URI, rowID);

getContext().getContentResolver().notifyChange(_uri, null);

return _uri;

}

throw new SQLException("Failed to add a record into " + uri);

}

@Override

public Cursor query(Uri uri, String[] projection, String selection,

String[] selectionArgs, String sortOrder) {

SQLiteQueryBuilder qb = new SQLiteQueryBuilder();

qb.setTables(TABLE_NAME);

switch (uriMatcher.match(uri)) {

case STUDENTS:

qb.setProjectionMap(PROJECTION_MAP);

break;

case STUDENT_ID:

qb.appendWhere(_ID + "=" + uri.getPathSegments().get(1));

break;

default:

throw new IllegalArgumentException("Unknown URI " + uri);

}

if (sortOrder == null || sortOrder == "") {

// sort on the name of the courses

sortOrder = NAME;

}

Cursor c = qb.query(db, projection, selection, selectionArgs, null,

null, sortOrder);

c.setNotificationUri(getContext().getContentResolver(), uri);

return c;

}

@Override

public int delete(Uri uri, String selection, String[] selectionArgs) {

int count = 0;

switch (uriMatcher.match(uri)) {

case STUDENTS:

count = db.delete(TABLE_NAME, selection, selectionArgs);

break;

case STUDENT_ID:

String id = uri.getPathSegments().get(1);

count = db.delete(TABLE_NAME, _ID

+ " = "

+ id

+ (!TextUtils.isEmpty(selection) ? " AND (" + selection

+ ')' : ""), selectionArgs);

break;

default:

throw new IllegalArgumentException("Unknown URI " + uri);

}

getContext().getContentResolver().notifyChange(uri, null);

return count;

}

@Override

public int update(Uri uri, ContentValues values, String selection,

String[] selectionArgs) {

int count = 0;

switch (uriMatcher.match(uri)) {

case STUDENTS:

count = db.update(TABLE_NAME, values, selection,

selectionArgs);

break;

case STUDENT_ID:

count = db.update(

TABLE_NAME,

values,

_ID

+ " = "

+ uri.getPathSegments().get(1)

+ (!TextUtils.isEmpty(selection) ? " AND ("

+ selection + ')' : ""), selectionArgs);

break;

default:

throw new IllegalArgumentException("Unknown URI " + uri);

}

getContext().getContentResolver().notifyChange(uri, null);

return count;

}

@Override

public String getType(Uri uri) {

switch (uriMatcher.match(uri)) {

/**

* Get all records

case STUDENTS:

return "vnd.android.cursor.dir/vnd.example.students";

/**

* Get a particular record

case STUDENT_ID:

return "vnd.android.cursor.item/vnd.example.students";

default:

throw new IllegalArgumentException("Unsupported URI: " + uri);

}