Java反射机制，实现Excel的导入与导出

一、下载jxl.jar包导入到工程中

http://download.youkuaiyun.com/detail/lrici/9758600

二、新建Book.Java

package com.cc.reflection;

public class Book {
	
	private int id;
	private String name;
	private String type;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getType() {
		return type;
	}
	public void setType(String type) {
		this.type = type;
	}
	

}

三、新建ExcelUtil.java

package com.cc.utils;


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

import javax.rmi.CORBA.Util;

import com.cc.reflection.Book;
import com.cc.reflection.ExcelBook;

import jxl.Sheet;
import jxl.Workbook;
import jxl.read.biff.BiffException;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
import jxl.write.WriteException;

public class ExcelUtil {
	
	
    //通用的导出方法
	public static void excelOut(ArrayList ar, String str) {
		WritableWorkbook bWorkbook = null;

		try {
			bWorkbook = Workbook.createWorkbook(new File(str));
			WritableSheet sheet = bWorkbook.createSheet("sheet", 0);
			for (int i = 0; i < ar.size(); i++) {
				Object ob = ar.get(i);
				Class class1 = ob.getClass();
				Field[] fields = class1.getDeclaredFields();
				for (int j = 0; j < fields.length; j++) {
					fields[j].setAccessible(true);
					Label label = new Label(j, i, String.valueOf(fields[j].get(ob)));
					sheet.addCell(label);
			
				}
			}
			bWorkbook.write();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				bWorkbook.close();
			} catch (WriteException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}

	}
	//通用的导入方法
	public static ArrayList excelIn(Class class1,String str){
		ArrayList arrayList =new ArrayList();
		Workbook bWorkbook =null;
		try {
			bWorkbook=Workbook.getWorkbook(new File(str));
			Sheet sheet=bWorkbook.getSheet(0);
			Field[] fields=class1.getDeclaredFields();
			for (int i = 0; i < sheet.getRows(); i++) {
				//不知道获取的对象是什么，所以用object来代替
				Object object=class1.newInstance();  
				for (int j = 0; j < fields.length; j++) {
					fields[j].setAccessible(true);
					String string=sheet.getCell(j,i).getContents();
					//如果获取的是一个字符串类型的数据
					if(fields[j].getType().toString().equals("class java.lang.String")){
						//将获取到的数据封装到object对象中
						fields[j].set(object,string);
					}else if(fields[j].getType().toString().equals("int")){
						fields[j].set(object,Integer.valueOf(string));
						
					}
				}
				arrayList.add(object);
				
			}
		} catch (BiffException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			bWorkbook.close();
		}
		return arrayList;
	}
	
	public static void main(String[] args) {
		
//		//将数据导出到Excel中
//		ExcelBook book = new ExcelBook();
//		ArrayList<Book> arrayList = new ArrayList<Book>();
//		Book bo = new Book();
//		bo.setId(1);
//		bo.setName("酒馆");
//		bo.setType("生活");
//
//		Book bo1 = new Book();
//		bo1.setId(2);
//		bo1.setName("酒馆1");
//		bo1.setType("生活1");
//
//		arrayList.add(bo);
//		arrayList.add(bo1);
//		ExcelUtil.excelOut(arrayList, "D:/jiudina.xls");
		
		//将Excel中的数据导入
		ArrayList<Book> arrayList2 = ExcelUtil.excelIn(Book.class,"D:/jiudina.xls");
		for (Book book1 : arrayList2) {
			System.out.println(book1.getName()+book1.getType());
		}
		
	}

}

四、点击运行，需要保证D盘有jiudina.xls 文件且文件中内容符合Book.java的对应类型