java反射机制入门04

package com.rainmer.main;

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

import jxl.Cell;
import jxl.Sheet;
import jxl.Workbook;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
import jxl.write.WriteException;

import com.rainmer.bean.Book;

public class ExcleBook {
    public void excleOut(ArrayList<Book> ar){
        WritableWorkbook book = null;//excle对象
        try{
            //创建excle对象
            book = Workbook.createWorkbook(new File("G:/book.xls"));
            //通过excle对象创建一个选项卡对象
            WritableSheet sheet = book.createSheet("sheet", 0);
            for (int i = 0; i < ar.size(); i++) {
                //创建一个单元格对象
                Label la0 = new Label(0,i,String.valueOf(ar.get(i).getId()));
                Label la1 = new Label(1,i,ar.get(i).getName());//创建单元格。参数说明：列，行，值
                Label la2 = new Label(2,i,ar.get(i).getType());
                //将创建好的单元格对象放入选项卡中
                sheet.addCell(la0);
                sheet.addCell(la1);
                sheet.addCell(la2);
            }
            //写入目标路径
            book.write();
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            try {
                book.close();
            } catch (WriteException | IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
    }
    
    public ArrayList<Book> excleIn(){
        ArrayList<Book> ar = new ArrayList<Book>();
        Workbook book = null;
        try{
            book = Workbook.getWorkbook(new File("G:/book.xls"));
            Sheet sheet = book.getSheet(0);
            for (int i = 0; i < sheet.getRows(); i++) {
                Book bo = new Book();
                Cell cell = sheet.getCell(0,i);//Cell读取的时候的单元格，列，行
                bo.setId(Integer.valueOf(cell.getContents()));
                bo.setName(sheet.getCell(1, i).getContents());
                bo.setType(sheet.getCell(2, i).getContents());
                ar.add(bo);
            }
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            book.close();
        }
        return ar;
    }
    
    public static void main(String[] args) {
        ExcleBook book = new ExcleBook();
        
        ArrayList<Book> ar = new ArrayList<Book>();
        Book bo1 = new Book();
        bo1.setId(1);
        bo1.setName("火影之鸣人重生");
        bo1.setType("同人");
        Book bo2 = new Book();
        bo2.setId(2);
        bo2.setName("我和我的老婆大人");
        bo2.setType("都市");
        ar.add(bo1);
        ar.add(bo2);
        
        book.excleOut(ar);
        
        ArrayList<Book> result = book.excleIn();
        for (int i = 0; i < result.size(); i++) {
            System.out.println(result.get(i).getName());
        }
    }
}

package com.rainmer.util;

import java.io.File;
import java.lang.reflect.Field;
import java.util.ArrayList;

import jxl.Sheet;
import jxl.Workbook;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;

import com.rainmer.bean.Book;

public class ExcleUtil {
    
    //如果有一个项目，
    //要求你实现图书信息导入导出，用户信息导入导出，借阅信息导入导出，维护信息导入导出，管理信息导入导出。。。。。
    public void excleOut(ArrayList ar, String str){
        WritableWorkbook book = null;
        try {
            book = Workbook.createWorkbook(new File(str));
            WritableSheet sheet = book.createSheet("sheet", 0);
            for(int i = 0;i<ar.size();i++){
                Object ob = ar.get(i);
                Class cl = ob.getClass();
                Field[] fi = cl.getDeclaredFields();
                for(int j = 0;j<fi.length;j++){
                    fi[j].setAccessible(true);
                    Label la = new Label(j, i, String.valueOf(fi[j].get(ob)));
                    sheet.addCell(la);
                }
            }
            book.write();
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            try {
                book.close();
            } catch (Exception e) {
                e.printStackTrace();
            } 
        }
    }
    
    public ArrayList excleIn(Class cl, String str){
        ArrayList ar = new ArrayList();
        Workbook book = null;
        try{
            book = Workbook.getWorkbook(new File(str));
            Sheet sheet = book.getSheet(0);
            Field[] fi = cl.getDeclaredFields();
            for (int i = 0; i < sheet.getRows(); i++) {
                Object ob = cl.newInstance();
                for (int j = 0; j < fi.length; j++) {
                    fi[j].setAccessible(true);
                    String con = sheet.getCell(j, i).getContents();
                    if(fi[j].getType().toString().equals("class java.lang.String")){
                        fi[j].set(ob, con);
                    }else if(fi[j].getType().toString().equals("int")){
                        fi[j].setInt(ob, Integer.valueOf(con));
                    }
                }
                ar.add(ob);
            }
        }catch(Exception e){
            e.printStackTrace();
        }
        return ar;
    }
    
    public static void main(String[] args) {
        ExcleUtil util = new ExcleUtil();
        ArrayList<Book> ar = new ArrayList<Book>();
        Book bo1 = new Book();
        bo1.setId(1);
        bo1.setName("火影之鸣人重生");
        bo1.setType("同人");
        Book bo2 = new Book();
        bo2.setId(2);
        bo2.setName("我和我的老婆大人");
        bo2.setType("都市");
        ar.add(bo1);
        ar.add(bo2);
        util.excleOut(ar, "G:/bookA.xls");