[TIL6] 카카오 REST API를 활용해서 도서 검색 하기

카카오 책 검색 API를 사용하여 도서 정보 검색할 수 있는 기능을 구현해보았다.

검색된 도서 정보를 PDF파일로 저장하도록 했다.

콘솔창에서 실행되며 검색할 도서의 제목을 입력 받아 검색 결과를 PDF파일로 저장하기까지 했다.

https://developers.kakao.com/ 접속

내 애플리케이션 클릭

정보 입력

REST API키 복사

https://developers.kakao.com/docs/latest/ko/daum-search/dev-guide 에서

https://developers.kakao.com/docs/latest/ko/daum-search/dev-guide#search-book 참고

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>JavaProject02</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>15</maven.compiler.source>
        <maven.compiler.target>15</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
<dependencies>
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi</artifactId>
        <version>5.2.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>5.2.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>2.17.1</version>
    </dependency>
    <dependency>
        <groupId>com.itextpdf</groupId>
        <artifactId>itext7-core</artifactId>
        <version>7.1.16</version>
    </dependency>
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>2.8.9</version>
    </dependency>
    <dependency>
        <groupId>com.squareup.okhttp3</groupId>
        <artifactId>okhttp</artifactId>
        <version>4.9.3</version>
    </dependency>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.13</version>
    </dependency>
</dependencies>
</project>

package kr.book.search;

public class Book {
    private String title;
    private String authors;
    private String publisher;
    private String thumbnail;

    public Book() {
    }

    public Book(String title, String authors, String publisher, String thumbnail) {
        this.title = title;
        this.authors = authors;
        this.publisher = publisher;
        this.thumbnail = thumbnail;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getAuthors() {
        return authors;
    }

    public void setAuthors(String authors) {
        this.authors = authors;
    }

    public String getPublisher() {
        return publisher;
    }

    public void setPublisher(String publisher) {
        this.publisher = publisher;
    }

    public String getThumbnail() {
        return thumbnail;
    }

    public void setThumbnail(String thumbnail) {
        this.thumbnail = thumbnail;
    }

    @Override
    public String toString() {
        return "Book{" +
                "title='" + title + '\'' +
                ", authors='" + authors + '\'' +
                ", publisher='" + publisher + '\'' +
                ", thumbnail='" + thumbnail + '\'' +
                '}';
    }
}

package kr.book.search;

import com.google.gson.*;
import okhttp3.*;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class KakaoBookApi {
    public static final String API_KEY = " ---- ";
    private static final String API_BASE_URL = "<https://dapi.kakao.com/v3/search/book>";
    private static final OkHttpClient client = new OkHttpClient();
    private static final Gson gson = new Gson();

    //책 검색 메서드
    public static List searchBooks(String title) throws IOException {
        HttpUrl.Builder urlBuilder = HttpUrl.parse(API_BASE_URL).newBuilder();
        urlBuilder.addQueryParameter("query", title);

        Request request = new Request.Builder()
                .url(urlBuilder.build())
                .addHeader("Authorization", "KakaoAK " + API_KEY)
                .build();

        try (Response response = client.newCall(request).execute()) {
            if (!response.isSuccessful()) throw new IOException("Request failed: " + response);

            JsonObject jsonResponse = gson.fromJson(response.body().charStream(), JsonObject.class);
            JsonArray documents = jsonResponse.getAsJsonArray("documents");

            List books = new ArrayList<>();
            for (JsonElement document : documents) {
                JsonObject bookJson = document.getAsJsonObject();
                Book book = new Book(
                        bookJson.get("title").getAsString(),
                        bookJson.getAsJsonArray("authors").toString(), // 수정된 부분
                        bookJson.get("publisher").getAsString(),
                        bookJson.get("thumbnail").getAsString()
                );
                books.add(book);
            }
            return books;
        }
    }
}	

package kr.book.search;

import java.io.IOException;
import java.util.List;
import java.util.Scanner;

public class BookSearchMain {
    public static void main(String[] args) {
        try{
            Scanner scanner = new Scanner(System.in);
            System.out.print("도서제목을 입력하세요:");
            String bookTitle = scanner.nextLine();
            List<Book> books = KakaoBookApi.searchBooks(bookTitle);

            if(books.isEmpty()){
                System.out.println("검색 결과가 없습니다.");

            }else{
                for(Book book : books){
                    System.out.println(book);
                }
                
            }
        }catch(IOException e){
            System.out.println("에러가 발생했습니다.: "+e.getMessage());
        }
    }
}

이렇게 실행했을 때 터미널에 아래처럼 뜸

이제 Pdf파일로 저장되게 해보자

위 코드 변경

package kr.book.search;

import java.io.IOException;
import java.util.List;
import java.util.Scanner;

public class BookSearchMain {
    public static void main(String[] args) {
        try{
            Scanner scanner = new Scanner(System.in);
            System.out.print("도서제목을 입력하세요:");
            String bookTitle = scanner.nextLine();
            List<Book> books = KakaoBookApi.searchBooks(bookTitle);

            if(books.isEmpty()){
                System.out.println("검색 결과가 없습니다.");

            }else{
                for(Book book : books){
                    System.out.println(book);
                } //여기서부터 추가
                String fileName = "도서목록.pdf";
                PdfGenerator.generateBookListPdf(books,fileName);
                System.out.println(fileName + "파일이 생성되었습니다.");//여기까지
            }
        }catch(IOException e){
            System.out.println("에러가 발생했습니다.: "+e.getMessage());
        }
    }
}

package kr.book.search;

import com.itextpdf.kernel.colors.ColorConstants;
import com.itextpdf.kernel.font.PdfFont;
import com.itextpdf.kernel.font.PdfFontFactory;
import com.itextpdf.kernel.pdf.*;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Cell;
import com.itextpdf.layout.element.Image;
import com.itextpdf.layout.element.Paragraph;
import com.itextpdf.layout.element.Table;
import com.itextpdf.layout.property.TextAlignment;
import com.itextpdf.layout.property.UnitValue;
import com.itextpdf.io.font.PdfEncodings;
import com.itextpdf.io.image.ImageData;
import com.itextpdf.io.image.ImageDataFactory;

import javax.swing.text.StyleConstants;
import java.io.*;
import java.util.*;
import java.net.MalformedURLException;
public class PdfGenerator {
    public static void generateBookListPdf(List<Book> books, String fileName) throws FileNotFoundException {
        PdfWriter writer = new PdfWriter(fileName);
        PdfDocument pdf = new PdfDocument(writer);
        Document document = new Document(pdf);
        document.setFontSize(12);

        //폰트
        PdfFont font = null;
        try{
            font = PdfFontFactory.createFont("Hancom Gothic Regular.ttf", PdfEncodings.IDENTITY_H, true);
        }catch (IOException e1){
            e1.printStackTrace();
        }
        document.setFont(font);
        //타이틀추가
        Paragraph titleParagraph = new Paragraph("도서 목록");
        titleParagraph.setFontSize(24);
        titleParagraph.setTextAlignment(TextAlignment.CENTER);
        titleParagraph.setBold();
        document.add(titleParagraph);

        //도서정보 테이블
        Table table = new Table(UnitValue.createPointArray(new float[]{2,2,2,2}));
        table.setWidth(UnitValue.createPercentValue(100));
        table.setMarginTop(20);

        //테이블 헤더
        table.addHeaderCell(createCell("제목", true));
        table.addHeaderCell(createCell("저자", true));
        table.addHeaderCell(createCell("출판사", true));
        table.addHeaderCell(createCell("이미지", true));

        //도서정보 테이블에 추가
        for(Book book : books){
            table.addCell(createCell(book.getTitle(), false));
            table.addCell(createCell(book.getAuthors(), false));
            table.addCell(createCell(book.getPublisher(), false));

            try{
                ImageData imageData = ImageDataFactory.create(book.getThumbnail());
                Image image = new Image(imageData);
                image.setAutoScale(true);
                table.addCell(new Cell().add(image).setPadding(5));

            }catch (MalformedURLException e){
                table.addCell(createCell("이미지 불러오기 실패", false));
            }
        }
        document.add(table);
        document.close();
    }
    private static Cell createCell(String content, boolean isHeader){
        Paragraph paragraph = new Paragraph(content);
        Cell cell = new Cell().add(paragraph);
        cell.setPadding(5);
        if(isHeader){
            cell.setBackgroundColor(ColorConstants.LIGHT_GRAY);
            cell.setFontSize(14);
            cell.setBold();
        }
        return cell;
    }
}

실행 결과
.
.
.
파일이 생겼다.