apache POI 操作excel<导入导出>

1、首先导入maven依赖

        <!-- POI核心依赖 -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.8</version>
        </dependency>
        <!-- 为POI支持Office Open XML -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.8</version>
        </dependency>

2、MicroUtil.java工具类

package com.yinz.tool.j2ee;

import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFDataFormat;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.util.WorkbookUtil;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import com.yinz.tool.ReflectUtil;

/**
 *
 * @description: 执行Microsoft文件 相关操作《导出/导入excel表格等》 
 * 需要用到POI相关jar包
 * @author yinz
 * 2016-11-9
 */
public class MicroUtil {

        public static void main(String[] args) throws Exception {
        String excelPath = "C:\Users\yinz\Desktop\场景2\场景2-样例数据_拜访记录.xls";
        Map<Integer, String> indexMapAtt = new HashMap<Integer, String>();
        indexMapAtt.put(0, "mbActivityInfoId");
        indexMapAtt.put(1, "activity");
        indexMapAtt.put(2, "activityName");
        indexMapAtt.put(3, "sendDate");
        indexMapAtt.put(4, "state");
        indexMapAtt.put(5, "isDelete");
        indexMapAtt.put(6, "customerId");
        indexMapAtt.put(7, "customerGender");
        indexMapAtt.put(8, "customerBirthDay");
        indexMapAtt.put(9, "empNo");
        indexMapAtt.put(10, "noteType");
        indexMapAtt.put(11, "contactDate");
        indexMapAtt.put(12, "remark");
        List<ContactRecord> result = readExcel(excelPath, null, 1, indexMapAtt, ContactRecord.class);
        System.out.println(result);
    }

    /**
     * 导出excel表格到输出流<可用于web界面导出excel表格>
     * @param response ： 输出流
     * @param result ： 需要导出的数据java对象列表
     * @param name ： 文件名
     * @param excelHead ： 表格列名
     * @param params ： 列对应的对象属性名
     * @param isAddIndex ： 是否增加序列号
     */
    public static void exportExcel(HttpServletResponse response, List<?> result, String name, String[] excelHead, Object[] params, boolean isAddIndex) {
        //创建excel表格
        HSSFWorkbook wb = new HSSFWorkbook();  
        //长度不能超过31个字符，并且不能包含部分特殊字符，使用如下方法，可将特殊字符替换为空格，长度超过31的进行
        name = WorkbookUtil.createSafeSheetName(name);
        HSSFSheet sheet = wb.createSheet(name); 
        String[] head = null;
        //如果增加序号，第一列设为序号，重新生成head数组
        if (isAddIndex)
        {
            head = new String[excelHead.length + 1];
            head[0] = "序列号";
               for (int i = 0; i < excelHead.length; i++)
               {
                   head[i+1] = excelHead[i];
               }
        }
        else
        {
            head = excelHead;
        }
        for(int i=0;i<head.length;i++){
            sheet.setColumnWidth(i, 6000);
        }
        //Rows are 0 based.
        HSSFRow row = sheet.createRow((int) 0);  
        HSSFCellStyle style = wb.createCellStyle();  
        HSSFCellStyle style2 = wb.createCellStyle();
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 创建一个居中格式
        HSSFDataFormat format = wb.createDataFormat();  
        style2.setDataFormat(format.getFormat("@"));
        
        for(int i=0;i<head.length;i++){
            HSSFCell cell = row.createCell((short) i);  
            cell.setCellValue(head[i]);  
            cell.setCellStyle(style); 
            cell.setCellType(HSSFCell.CELL_TYPE_STRING);
            sheet.setDefaultColumnStyle(i, style2);
        }
        int count = 1;
        if (result != null)
        {
          for (Object obj : result){
            
            int i = 0;
              row = sheet.createRow(count);
              //先增加序号
            if (isAddIndex)
            {
                row.createCell((short) 0).setCellValue(count);
                i++;                
            }
            for (Object attrName:params)
            {
                HSSFCell cell = row.createCell((short) i);
                cell.setCellStyle(style2);
                Object value = ReflectUtil.getObjAttributeValue(obj, (String)attrName);
                cell.setCellValue(value == null ? "" : value.toString());
                cell.setCellType(HSSFCell.CELL_TYPE_STRING);
                i++;
            }
            count++;
          }
        } 
        try  
        {  
            String filename = name+".xls";//设置文件名   
            response.reset();
            response.setHeader("Content-Disposition", "attachment; filename=" + java.net.URLEncoder.encode(filename, "UTF-8"));
            response.setContentType("application/vnd.ms-excel");
            OutputStream fout = response.getOutputStream();
            //将excel写到输出流
            wb.write(fout);  
            fout.flush();
            fout.close();
            response.getOutputStream().flush();
            response.getOutputStream().close();
          
        }  
        catch (Exception e)  
        {  
            e.printStackTrace();  
        }  
    }
    
    //读取excel表格数据 
    
    /**
     * 读取excel表格内容到java对象
     * @param inStream  excel文件输入流
     * @param sheetPage 要读取的sheet页(0 based)，若为null,则读取第1页
     * @param startRow  从第几行开始读取
     * @param indexMapAtt excel表单cell与java对象对应关系
     * @param clazz  要生成的java类型
     * @return
     * @throws Exception
     */
    public static <T> List<T> readExcel(InputStream inStream, Integer[] sheetPage, Integer startRow, Map<Integer, String> indexMapAtt, Class<T> clazz) throws Exception {
        startRow = startRow == null ? 0 : startRow;
        List<T> result = new ArrayList<T>();
        Workbook wb = new HSSFWorkbook(inStream);;
        Sheet sheet = null;
        if(sheetPage == null || sheetPage.length <= 0) {
            sheet = wb.getSheetAt(0);
            readSheet(sheet, result, startRow, indexMapAtt, clazz);
        } else {
            for(Integer sheetIndex : sheetPage) {
                sheet = wb.getSheetAt(sheetIndex);
                readSheet(sheet, result, startRow, indexMapAtt, clazz);
            }
        }
        
        return result;
    }
    
    /**
     * 
     * @param excelPath  excel表格路径
     * @param sheetPage  要读取的excel中的sheet所有 、0开始
     * @param startRow   开始读取的数据的行标  ，0开始
     * @param indexMapAtt  列索引与对象属性对应map
     * @param clazz   每行记录所对应的java对象
     * @return
     * @throws Exception
     */
    @SuppressWarnings("resource")
    public static <T> List<T> readExcel(String excelPath, Integer[] sheetPage, Integer startRow, Map<Integer, String> indexMapAtt, Class<T> clazz) throws Exception {
        startRow = startRow == null ? 0 : startRow;
        List<T> result = new ArrayList<T>();
        InputStream inStream = new FileInputStream(excelPath);
        Workbook wb = null;
        if(excelPath.matches("^.+\.(?i)(xls)$")) {
            //excel2003
            wb = new HSSFWorkbook(inStream);
        } else if(excelPath.matches("^.+\.(?i)(xlsx)$")) {
            //excel2007
            wb = new XSSFWorkbook(inStream);
        } else {
            return null;
        }
        Sheet sheet = null;
        if(sheetPage == null || sheetPage.length <= 0) {
            sheet = wb.getSheetAt(0);
            readSheet(sheet, result, startRow, indexMapAtt, clazz);
        } else {
            for(Integer sheetIndex : sheetPage) {
                sheet = wb.getSheetAt(sheetIndex);
                readSheet(sheet, result, startRow, indexMapAtt, clazz);
            }
        }
        
        return result;
    }
    
    //读取excel中的sheet数据、并为java对象集合赋值
    private static <T> void readSheet(Sheet sheet, List<T> result, Integer startRow, Map<Integer, String> indexMapAtt, Class<T> resultType) throws Exception {
        //获取总行数
        int totalRows = sheet.getPhysicalNumberOfRows();
        
        T t;
        for(int i = startRow; i < totalRows; i++) {
            Row row = sheet.getRow(i);
            if(row == null) {
                continue;
            }
            
            t = resultType.newInstance();
            Set<Integer> cellIndexSet = indexMapAtt.keySet();
            for(Integer index : cellIndexSet) {
                Cell cell = row.getCell(index);
                if(cell == null) {
                    continue;
                }
                cell.setCellType(HSSFCell.CELL_TYPE_STRING);  
                ReflectUtil.setObjAttributeValue(t, indexMapAtt.get(index), cell.getStringCellValue() == null ? "" : cell.getStringCellValue());
            }
            result.add(t);
        }
    }
}

反射工具类：ReflectUtil.java

package com.yinz.tool;

import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;

/**
 * 
 * @description: 反射工具类 
 * @author yinz
 * 2016-11-9
 */
public class ReflectUtil {

    /**
     * 将对象属性和值以map存储，默认包含属性值为null的属性
     * @param obj
     * @return
     */
    public static Map<String, Object> obj2map(Object obj) {
        return obj2map(obj, true);
    }
    
    /**
     * 将对象属性和值以map存储
     * @param obj
     * @param isContainNullValue ： 是否包含属性中为空的属性
     * @return
     */
    public static Map<String, Object> obj2map(Object obj, boolean isContainNullValue) {
        Map<String, Object> map = new HashMap<String, Object>();
        
        Field[] fList = obj.getClass().getDeclaredFields();
        try {
            for(Field f : fList) {
                f.setAccessible(true);
                if(isContainNullValue) {
                    map.put(f.getName(), f.get(obj));
                } else {
                    if(f.get(obj) != null && f.get(obj) != "") {
                        map.put(f.getName(), f.get(obj));
                    }
                }
            }
        } catch (Exception e) {
            return null;
        }
        return map;
    }
    
    /**
     * 获取对象指定属性值
     * @param obj
     * @param attName
     * @return
     */
    public static Object getObjAttributeValue(Object obj, String attName) {
        return getObjAttributeValue(obj, attName, "");
    }
    
    /**
     * 获取对象指定属性的值
     * @param obj : 查询对象
     * @param attName ： 要获取的属性名
     * @param defVal ： 默认值
     * @return
     */
    public static Object getObjAttributeValue(Object obj, String attName, String defVal) {
        Object value = null;
        Field field = null;
        try {
            field = obj.getClass().getDeclaredField(attName);
            field.setAccessible(true);
            value = field.get(obj);
        } catch (Exception e) {
            return defVal;
        }
        if(value == null || value.toString().trim().length() <= 0) {
            value = defVal;
        }
        return value;
    }
    
    /**
     * 为对象属性赋值
     * @param obj  要赋值的对象
     * @param attName 对象属性名
     * @param value 属性值
     */
    public static void setObjAttributeValue(Object obj, String attName, String value) {
        Field field = null;
        try {
            field = obj.getClass().getDeclaredField(attName);
            field.setAccessible(true);
            field.set(obj, value);
        } catch (Exception e) {
        }
    }
}

实体类：ContactRecord.java

package com.tianwen.nlp.pojo;

public class ContactRecord {
    private Integer id;

    private String mbActivityInfoId;

    private String activityType;

    private String activityName;

    private String sendDate;

    private String state;

    private String isDelete;

    private String customerId;

    private String customerGender;

    private String customerBirthday;

    private String empNo;

    private String noteType;

    private String contactDate;

    private String remark;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getMbActivityInfoId() {
        return mbActivityInfoId;
    }

    public void setMbActivityInfoId(String mbActivityInfoId) {
        this.mbActivityInfoId = mbActivityInfoId == null ? null : mbActivityInfoId.trim();
    }

    public String getActivityType() {
        return activityType;
    }

    public void setActivityType(String activityType) {
        this.activityType = activityType == null ? null : activityType.trim();
    }

    public String getActivityName() {
        return activityName;
    }

    public void setActivityName(String activityName) {
        this.activityName = activityName == null ? null : activityName.trim();
    }

    public String getSendDate() {
        return sendDate;
    }

    public void setSendDate(String sendDate) {
        this.sendDate = sendDate == null ? null : sendDate.trim();
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state == null ? null : state.trim();
    }

    public String getIsDelete() {
        return isDelete;
    }

    public void setIsDelete(String isDelete) {
        this.isDelete = isDelete == null ? null : isDelete.trim();
    }

    public String getCustomerId() {
        return customerId;
    }

    public void setCustomerId(String customerId) {
        this.customerId = customerId == null ? null : customerId.trim();
    }

    public String getCustomerGender() {
        return customerGender;
    }

    public void setCustomerGender(String customerGender) {
        this.customerGender = customerGender == null ? null : customerGender.trim();
    }

    public String getCustomerBirthday() {
        return customerBirthday;
    }

    public void setCustomerBirthday(String customerBirthday) {
        this.customerBirthday = customerBirthday == null ? null : customerBirthday.trim();
    }

    public String getEmpNo() {
        return empNo;
    }

    public void setEmpNo(String empNo) {
        this.empNo = empNo == null ? null : empNo.trim();
    }

    public String getNoteType() {
        return noteType;
    }

    public void setNoteType(String noteType) {
        this.noteType = noteType == null ? null : noteType.trim();
    }

    public String getContactDate() {
        return contactDate;
    }

    public void setContactDate(String contactDate) {
        this.contactDate = contactDate == null ? null : contactDate.trim();
    }

    public String getRemark() {
        return remark;
    }

    public void setRemark(String remark) {
        this.remark = remark == null ? null : remark.trim();
    }
}

此处用与上传的excel文件：http://files.cnblogs.com/files/yinz/场景2-样例数据_拜访记录.rar

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原文地址：https://www.cnblogs.com/yinz/p/7109937.html