This code is to simply query the Google Books API and to return the data in JSON. Then, the JSON data is parsed and the Book Name, Authors and the Publication Date are stored in an ArrayList of type 'Book'. There is a problem when tryiing to parse the Array of JSON data. It's not coming out of the loop at Line 70 in MainActivity.java class. What might be the possible solution?
The repository is https://github.com/PRAVEENT26/GoogleBooksAPI
I'll list the files here too.
MainActivity.java
package com.praveent.googlebooksapi;
import android.net.Uri;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Scanner;
import static java.lang.System.in;
public class MainActivity extends AppCompatActivity {
EditText query;
Button submit;
String dataJSON;
TextView test;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
query = (EditText) findViewById(R.id.query);
submit = (Button) findViewById(R.id.submit);
final String baseURL = "https://www.googleapis.com/books/v1/volumes";
final String queryParameter = "q";
submit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String searchQuery = query.getText().toString();
Uri tempUri = Uri.parse(baseURL).buildUpon().appendQueryParameter(queryParameter, searchQuery).build();
URL url;
try {
url = new URL(tempUri.toString());
new fetchDataAsync().execute(url);
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
public void jsonParsing() throws JSONException {
JSONObject response = new JSONObject(dataJSON);
int total = response.getInt("totalItems");
TextView test = (TextView) findViewById(R.id.test);
int flag = 0;
JSONArray bookArray = response.getJSONArray("items");
//test.setText(Integer.toString(bookArray.length()));
ArrayList < Book > bookList = new ArrayList < > ();
ListView listView = (ListView) findViewById(R.id.commonView);
for (int i = 0; i < total; i++) {
flag++;
JSONObject volume = bookArray.getJSONObject(i);
if (volume.has("volumeInfo")) {
JSONObject tempObject = volume.getJSONObject("volumeInfo");
String bookName = tempObject.getString("title");
String authorName = null;
if (tempObject.has("authors")) {
JSONArray authorsArray = tempObject.getJSONArray("authors");
for (int j = 0; j < authorsArray.length(); j++) {
authorName += authorsArray.getString(j);
if (j < authorsArray.length() - 1) {
authorName += ", ";
}
}
}
String publicationDate = tempObject.getString("publishedDate");
bookList.add(new Book(bookName, authorName, publicationDate));
}
}
test.setText(Integer.toString(flag));
BookAdapter bookAdapter = new BookAdapter(this, bookList);
listView.setAdapter(bookAdapter);
}
public class fetchDataAsync extends AsyncTask < URL, Void, String > {
@Override
protected String doInBackground(URL...url) {
URL searchURL = url[0];
try {
dataJSON = fetchData(searchURL);
} catch (IOException e) {
e.printStackTrace();
}
return dataJSON;
}
@Override
protected void onPostExecute(String s) {
try {
jsonParsing();
} catch (JSONException e) {
e.printStackTrace();
}
}
}
public static String fetchData(URL url) throws IOException {
HttpURLConnection newConnection = (HttpURLConnection) url.openConnection();
try {
InputStream newStream = newConnection.getInputStream();
Scanner scanner = new Scanner(newStream);
scanner.useDelimiter("\\A");
boolean hasInput = scanner.hasNext();
if (hasInput) {
return scanner.next();
} else
return null;
} finally {
newConnection.disconnect();
}
}
}BookAdapter.java
package com.praveent.googlebooksapi;
import android.app.Activity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
public class BookAdapter extends ArrayAdapter<Book>{
public BookAdapter(Activity context, ArrayList<Book> bookArrayListAdapter) {
super(context, 0, bookArrayListAdapter);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View tempView = convertView;
if (tempView == null){
tempView = LayoutInflater.from(getContext()).inflate(R.layout.book_details,parent,false);
}
Book temp = getItem(position);
ImageView imageView = (ImageView) tempView.findViewById(R.id.image);
TextView nameView = (TextView) tempView.findViewById(R.id.bookName);
TextView authorView = (TextView) tempView.findViewById(R.id.authorName);
TextView dateView = (TextView) tempView.findViewById(R.id.publishDate);
imageView.setImageResource(R.drawable.google);
nameView.setText(temp.getbookName());
authorView.setText(temp.getAuthorName());
dateView.setText(temp.getPublishedDate());
return tempView;
}
}Book.java //Custom Object
package com.praveent.googlebooksapi;
public class Book {
String bookName;
String authorName;
String publishedDate;
public Book(String name, String authors, String date){
bookName = name;
authorName = authors;
publishedDate = date;
}
public String getbookName() {
return bookName;
}
public String getAuthorName() {
return authorName;
}
public String getPublishedDate() {
return publishedDate;
}
}XML Layouts:
book_details.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="8dp">
<ImageView
android:layout_width="80dp"
android:layout_height="80dp"
android:padding="8dp"
android:id="@+id/image"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="8dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/bookName"
android:textSize="16dp" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/authorName"
android:textSize="16dp" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/publishDate"
android:textSize="16dp" />
</LinearLayout>
</LinearLayout>activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.praveent.googlebooksapi.MainActivity">
<EditText
android:id="@+id/query"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="8dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:hint="Enter the Book Query" />
<Button
android:id="@+id/submit"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SUBMIT QUERY" />
<TextView
android:id="@+id/test"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="8dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/commonView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp"/>
</LinearLayout>ANDROID MANIFEST FILE:
AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.praveent.googlebooksapi">
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>SAMPLE JSON DATA: Query Results in JSON. Click this to view the JSON structure.
Please help me run without any problems. Thanks in advance!
Try this,
try
{
JSONObject result = new JSONObject(resultResponse);
String kind = result.getString("kind");
JSONArray items_arr=result.getJSONArray("items");
for(int i=0;i<items_arr.length();i++)
{
JSONObject obj=items_arr.getJSONObject(i);
JSONObject volumeInfo_obj=obj.getJSONObject("volumeInfo");
String bookName=volumeInfo_obj.getString("title");
JSONArray volumeInfo_arr=volumeInfo_obj.getJSONArray("authors");
String authorName=volumeInfo_arr.getString(0);
String publicationDate=volumeInfo_obj.getString("publishedDate");
bookList.add(new Book(bookName, authorName, publicationDate));
}
BookAdapter bookAdapter = new BookAdapter(this, bookList);
listView.setAdapter(bookAdapter);
} catch (JSONException e) {
Constants.dismiss_progress_dialog();
e.printStackTrace();
}