到目前为止，我的图书列表代码运行良好。稍后我将发出 URL 请求，目前我正在研究该功能。然而，这里是Screenshot我的输出。它的作用是，对于我的作者部分，作者姓名以方括号打印，成熟度评级以带下划线的大写字母打印。我无法弄清楚如何以更用户友好的方式编辑我的输出。
这是我的 Java 类。
MainActivity.java
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ListView;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayList<Books> books = BookUtils.extractBooks();
// Find a reference to the {@link ListView} in the layout
ListView bookListView = (ListView) findViewById(R.id.list);
// Create a new {@link ArrayAdapter} of earthquakes
BookAdapter adapter = new BookAdapter(this, books);
// Set the adapter on the {@link ListView}
// so the list can be populated in the user interface
bookListView.setAdapter(adapter);
}
}
BookAdapter.java
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import java.util.List;
public class BookAdapter extends ArrayAdapter<Books> {
public BookAdapter(Context context, List<Books> books){
super(context, 0, books);
}
@Override
public View getView(int position, View convertView, ViewGroup parent){
View listItemView = convertView;
if (listItemView == null){
listItemView = LayoutInflater.from(getContext()).inflate(R.layout.book_list_item, parent, false);
}
Books currentBook = getItem(position);
TextView title = (TextView)listItemView.findViewById(R.id.book_title);
title.setText(currentBook.getTitle());
TextView authors = (TextView)listItemView.findViewById(R.id.book_author);
authors.setText(currentBook.getAuthors());
TextView publisher = (TextView)listItemView.findViewById(R.id.book_publisher);
publisher.setText(currentBook.getPublisher());
TextView publishingDate = (TextView)listItemView.findViewById(R.id.book_publishing_date);
publishingDate.setText(currentBook.getPublishedDate());
TextView language = (TextView)listItemView.findViewById(R.id.book_language);
language.setText(currentBook.getLanguage());
TextView pageCount = (TextView)listItemView.findViewById(R.id.book_page_count);
pageCount.setText(currentBook.getCount());
TextView printType = (TextView)listItemView.findViewById(R.id.book_print_type);
printType.setText(currentBook.getPrintType());
TextView maturityRating = (TextView)listItemView.findViewById(R.id.book_maturity_rating);
maturityRating.setText(currentBook.getMaturityRating());
return listItemView;
}
}
书籍.java
public class Books {
private String mTitle;
private String mAuthors;
private String mPublisher;
private String mPublishingDate;
private String mLanguage;
private String mCount;
private String mPrintType;
private String mMaturityRating;
public Books(String title, String authors, String publisher, String publishingDate, String language, String count, String printType, String maturityRating) {
mTitle = title;
mAuthors = authors;
mPublisher = publisher;
mPublishingDate = publishingDate;
mLanguage = language;
mCount = count;
mPrintType = printType;
mMaturityRating = maturityRating;
}
public String getTitle() {return mTitle;}
public String getAuthors(){return mAuthors;}
public String getPublisher(){return mPublisher;}
public String getPublishedDate(){return mPublishingDate;}
public String getLanguage(){return mLanguage;}
public String getCount(){return mCount;}
public String getPrintType(){return mPrintType;}
public String getMaturityRating(){return mMaturityRating;}
}
BookUtils.java
import android.util.Log;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
public final class BookUtils {
private static final String SAMPLE_JSON_RESPONSE = "{\n" +
" \"kind\": \"books#volumes\",\n" +
" \"totalItems\": 1117,\n" +
" \"items\": [\n" +
" {\n" +
" \"kind\": \"books#volume\",\n" +
" \"id\": \"IEk2m00o9_IC\",\n" +
" \"etag\": \"+odAmEu8Vk0\",\n" +
" \"selfLink\": \"https://www.googleapis.com/books/v1/volumes/IEk2m00o9_IC\",\n" +
" \"volumeInfo\": {\n" +
" \"title\": \"Android Apps Security\",\n" +
" \"authors\": [\n" +
" \"Sheran Gunasekera\"\n" +
" ],\n" +
" \"publisher\": \"Apress\",\n" +
" \"publishedDate\": \"2012-09-12\",\n" +
" \"description\": \"Android Apps Security provides guiding principles for how to best design and " +
"develop Android apps with security in mind. It explores concepts that can be used to secure apps and how " +
"developers can use and incorporate these security features into their apps. This book will provide developers with " +
"the information they need to design useful, high-performing, and secure apps that expose end-users to as little risk " +
"as possible. Overview of Android OS versions, features, architecture and security. Detailed examination of areas where " +
"attacks on applications can take place and what controls should be implemented to protect private user data In-depth guide " +
"to data encryption, authentication techniques, enterprise security and applied real-world examples of these concepts What you’ll " +
"learn How to identify data that should be secured How to use the Android APIs to ensure confidentiality and integrity of data " +
"How to build secure apps for the enterprise About Public Key Infrastructure, encryption APIs and how to implement them in apps " +
"About owners, access control lists and permissions to allow user control over App properties About client-server apps and how to manage " +
"authentication, transport layer encryption and server-side security Who this book is for This book is for intermediate and experienced Android " +
"app developers that are already familiar with writing apps from scratch. It discusses mechanisms on how apps can be secured so that private, end-user " +
"data is kept secure on the device and while in transit. If you’re just embarking on the path to Android development, then this book " +
"may prove to be a useful companion to other developer guides. Table of Contents Android Architecture & Security Controls " +
"The Foundation of an App Who Has Access? Designing and Developing 3 Sample Apps Using PKI & Encryption Interfacing with Web " +
"Services Writing for the Enterprise Designing and Developing 3 More Sample Apps Publishing and Selling Your Apps Malware, Spyware " +
"and Your End-User API Reference\",\n" +
" \"industryIdentifiers\": [\n" +
" {\n" +
" \"type\": \"ISBN_13\",\n" +
" \"identifier\": \"9781430240624\"\n" +
" },\n" +
" {\n" +
" \"type\": \"ISBN_10\",\n" +
" \"identifier\": \"1430240628\"\n" +
" }\n" +
" ],\n" +
" \"readingModes\": {\n" +
" \"text\": true,\n" +
" \"image\": true\n" +
" },\n" +
" \"pageCount\": 248,\n" +
" \"printType\": \"BOOK\",\n" +
" \"categories\": [\n" +
" \"Computers\"\n" +
" ],\n" +
" \"maturityRating\": \"NOT_MATURE\",\n" +
" \"allowAnonLogging\": true,\n" +
" \"contentVersion\": \"1.1.1.0.preview.3\",\n" +
" \"imageLinks\": {\n" +
" \"smallThumbnail\": \"http://books.google.com/books/content?id=IEk2m00o9_IC&printsec=frontcover&img=1&zoom=5&edge=curl&source=gbs_api\",\n" +
" \"thumbnail\": \"http://books.google.com/books/content?id=IEk2m00o9_IC&printsec=frontcover&img=1&zoom=1&edge=curl&source=gbs_api\"\n" +
" },\n" +
" \"language\": \"en\",\n" +
" \"previewLink\": \"http://books.google.ca/books?id=IEk2m00o9_IC&printsec=frontcover&dq=android&hl=&cd=1&source=gbs_api\",\n" +
" \"infoLink\": \"http://books.google.ca/books?id=IEk2m00o9_IC&dq=android&hl=&source=gbs_api\",\n" +
" \"canonicalVolumeLink\": \"http://books.google.ca/books/about/Android_Apps_Security.html?hl=&id=IEk2m00o9_IC\"\n" +
" },\n" +
" \"saleInfo\": {\n" +
" \"country\": \"CA\",\n" +
" \"saleability\": \"NOT_FOR_SALE\",\n" +
" \"isEbook\": false\n" +
" },\n" +
" \"accessInfo\": {\n" +
" \"country\": \"CA\",\n" +
" \"viewability\": \"PARTIAL\",\n" +
" \"embeddable\": true,\n" +
" \"publicDomain\": false,\n" +
" \"textToSpeechPermission\": \"ALLOWED\",\n" +
" \"epub\": {\n" +
" \"isAvailable\": true,\n" +
" \"acsTokenLink\": \"http://books.google.ca/books/download/Android_Apps_Security-sample-epub.acsm?id=IEk2m00o9_IC&format=epub&output=acs4_fulfillment_token&dl_type=sample&source=gbs_api\"\n" +
" },\n" +
" \"pdf\": {\n" +
" \"isAvailable\": true,\n" +
" \"acsTokenLink\": \"http://books.google.ca/books/download/Android_Apps_Security-sample-pdf.acsm?id=IEk2m00o9_IC&format=pdf&output=acs4_fulfillment_token&dl_type=sample&source=gbs_api\"\n" +
" },\n" +
" \"webReaderLink\": \"http://books.google.ca/books/reader?id=IEk2m00o9_IC&hl=&printsec=frontcover&output=reader&source=gbs_api\",\n" +
" \"accessViewStatus\": \"SAMPLE\",\n" +
" \"quoteSharingAllowed\": false\n" +
" },\n" +
" \"searchInfo\": {\n" +
" \"textSnippet\": \"This book will provide developers with the information they need to design useful, high-performing, and secure apps that expose end-users to as little risk as possible. Overview of Android OS versions, features, architecture and security.\"\n" +
" }\n" +
" }\n" +
" ]\n" +
"}";
private BookUtils() {
}
public static ArrayList<Books>extractBooks(){
ArrayList<Books> books = new ArrayList<>();
// Try to parse the SAMPLE_JSON_RESPONSE. If there's a problem with the way the JSON
// is formatted, a JSONException exception object will be thrown.
// Catch the exception so the app doesn't crash, and print the error message to the logs.
try {
JSONObject jsonResponse = new JSONObject(SAMPLE_JSON_RESPONSE);
JSONArray booksArray = jsonResponse.getJSONArray("items");
for(int i = 0; i < booksArray.length(); i++){
JSONObject currentBook = booksArray.getJSONObject(i);
JSONObject volumeInfo = currentBook.getJSONObject("volumeInfo");
String title = volumeInfo.getString("title");
String authors = volumeInfo.getString("authors");
String publisher = volumeInfo.getString("publisher");
String publishdDate = volumeInfo.getString("publishedDate");
String language = volumeInfo.getString("language");
String pageCount = volumeInfo.getString("pageCount");
String printType = volumeInfo.getString("printType");
String maturityRating = volumeInfo.getString("maturityRating");
Books book = new Books(title, authors, publisher, publishdDate, language, pageCount, printType, maturityRating);
books.add(book);
}
} catch (JSONException e) {
Log.e("QueryUtils", "Problem parsing the earthquake JSON results", e);
}
// Return the list of earthquakes
return books;
}
}
最佳答案
问题出在Stringauthors = volumeInfo.getString("authors");
因为authors是一个数组，所以你需要使用getJSONArray而不是getString，如下所示:
JSONArray authorsArray = volumeInfo.getJSONArray("authors");
这将为您提供作者数组，但由于 Book bean 中有简单的 String 类型，因此您需要准备一个字符串并附加所有作者，如下所示。
处理作者数组的 BookUtils 代码 fragment :
for(int i = 0; i < booksArray.length(); i++){
JSONObject currentBook = booksArray.getJSONObject(i);
JSONObject volumeInfo = currentBook.getJSONObject("volumeInfo");
JSONArray authorsArray = volumeInfo.getJSONArray("authors");
String authors = "";
for(int i=0; i<authorsArray.length();i++) {
authors = authors +","+authorsArray.getString(i);
}
//set the other strings as is
Books book = new Books(title, authors, publisher, publishdDate, language, pageCount, printType, maturityRating);
books.add(book);
}
关于java - 编辑从解析的 JSON 字符串中检索到的字符串，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40326632/