package com.eblly.xml;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

public class BookXml {
    /*
     * 獲取book.xml所有信息 ，幷封裝成對象
     */
    public List<Book> findAll(){
        InputStream is = null;
        //需要返回的書單
        List<Book> bookList = new ArrayList<>();
        try{
//            is = new FileInputStream("/home/eblly/program/java/eclipse/xmlhomework0704/src/book.xml");   //使用絕對路徑可以讀得出

　　　　　　　　File file = new File("src/book.xml"); //輸出File裏面的String參數

//            System.out.println(file);
//            is = new FileInputStream("src/book.xml");  //可以輸出
//            is = new FileInputStream("/src/book.xml");  //java.io.FileNotFoundException: /src/book.xml
//            is = new FileInputStream("./src/book.xml");  //可以輸出
//            is = new FileInputStream("./book.xml");   //java.io.FileNotFoundException: ./book.xml
//            is = new FileInputStream("/book.xml");   //java.io.FileNotFoundException: /book.xml
//            is = new FileInputStream("book.xml");   //java.io.FileNotFoundException: book.xml
            
            //這個使用相對路徑即可
//            is = this.getClass().getResourceAsStream("/book.xml");      //可以輸出
//            is = this.getClass().getResourceAsStream("src/book.xml");  //null
//            is = this.getClass().getResourceAsStream("./book.xml");   //null
//            is = this.getClass().getResourceAsStream("book.xml");    //null
//            System.out.println(this.getClass());                    //class com.eblly.xml.BookXml
//            System.out.println(this.getClass().getResource("/")); //file:/home/eblly/program/java/eclipse/xmlhomework0704/bin/
//            System.out.println(this.getClass().getResource("./"));//file:/home/eblly/program/java/eclipse/xmlhomework0704/bin/com/eblly/xml/
//            System.out.println(this.getClass().getResource("/.."));//null
//            System.out.println(this.getClass().getResource("."));//file:/home/eblly/program/java/eclipse/xmlhomework0704/bin/com/eblly/xml/
//            System.out.println(this.getClass().getResource("../"));//file:/home/eblly/program/java/eclipse/xmlhomework0704/bin/com/eblly/
//            System.out.println(this.getClass().getResource("../../"));//file:/home/eblly/program/java/eclipse/xmlhomework0704/bin/com/
//            System.out.println(this.getClass().getResource("../../../"));//file:/home/eblly/program/java/eclipse/xmlhomework0704/bin/
//            System.out.println(this.getClass().getResource("../../../../"));//null
//            is = this.getClass().getResourceAsStream("/xml/book.xml");      //可以
            
            
            /*
             * FileInputStream是指向/home/eblly/program/java/eclipse/xmlhomework0704，
             * 而this.getClass()是指向運行文件的目錄，即/home/eblly/program/java/eclipse/xmlhomework0704/bin
             * 
             * 如果把book.xml放到xml文件夾裏面，而xml文件是xmlhomework0704的子目錄的話，is = new FileInputStream("src/book.xml")需要
             * 把src改成xml. 而getResourceAsStream則無法獲得book.xml。
             * 如果把book.xml放到xml文件夾裏面，而xml文件是src的子目錄的話，，is = new FileInputStream("xml/book.xml")可以獲得文件，
             * is = this.getClass().getResourceAsStream("/xml/book.xml")也可以獲得文件。
             * 
             * 而 this.getClass().getResourceAsStream("/book.xml")的“根目錄”就是/home/eblly/program/java/eclipse/xmlhomework0704/bin，
             * 所以再怎麼上一層目錄還是不變。如果xml文件夾在src下，book.xml在xml文件夾中，使用/xml/book.xml可以獲得文件。
             * 
             * FileInputStream和this.getClass().getResourceAsStream("/book.xml")還有一個區別在於根目錄"/"的寫入與否。FileInputStream一系統
             * 根目錄爲根目錄，getResourceAsStream是以bin爲根目錄。
             * 
             */
            
//            URL str = this.getClass().getResource("/book.xml");   //file:/home/eblly/program/java/eclipse/xmlhomework0704/bin/book.xml
//            System.out.println(is);
            Document document = new SAXReader().read(is);
            Element root = document.getRootElement();
            //書裏面的元素
            List<Element> elementList = root.elements();
            for(Element e : elementList){
                Book book = new Book();
                book.setId(e.elementText("id"));
                book.setName(e.elementText("name"));
                book.setAuthor(e.elementText("author"));
                book.setPrice(e.elementText("price"));
                book.setImage(e.elementText("image"));
                book.setRemark(e.elementText("remark"));
                bookList.add(book);
            }
                
        }catch (Exception e){
            e.printStackTrace();
        }finally{
            try{
                is.close();
            }catch(Exception e){
                e.printStackTrace();
            }
        }
        return bookList;
    }
    
    public static void main(String[] args){
        BookXml bookxml = new BookXml();
        List<Book> list = bookxml.findAll();
        for(Book book : list){
            System.out.println("id號:" + book.getId());
            System.out.println("書名:" + book.getName());
            System.out.println("價格:" + book.getPrice());
            System.out.println("相片:" + book.getImage());
            System.out.println("簡介:" + book.getRemark());
            System.out.println();
        }
    }