java实现创建excel表并导出到本地

短命女 2022-05-19 03:38 191阅读 0赞

**java创建excel的效果图：**  
![这里写图片描述][70]

**java实现excel导入本地的效果图：**  
![这里写图片描述][70 1]

### 代码块 ###

**1. 创建Member类，此类用来创建对象，存储在excel表格中的数据**

package com.yu.bai.excel;
    
    import java.util.Date;
    //创建一个实体对象,用来存储到excel表中
    public class Member { 
        private Integer code;
        private String name;
        private Integer age;
        private Date birth;
    
        public Member(Integer code, String name, Integer age, Date birth) {
            super();
            this.code = code;
            this.name = name;
            this.age = age;
            this.birth = birth;
        }
    
        public Integer getCode() {
            return code;
        }
    
        public void setCode(Integer code) {
            this.code = code;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public Integer getAge() {
            return age;
        }
    
        public void setAge(Integer age) {
            this.age = age;
        }
    
        public Date getBirth() {
            return birth;
        }
    
        public void setBirth(Date birth) {
            this.birth = birth;
        }
    }

**2. 初始化数据，并运行**

package com.yu.bai.excel;
    
    import java.io.FileOutputStream;
    import java.io.OutputStream;
    import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    import java.util.Set;
    import java.util.UUID;
    
    import org.apache.poi.hssf.usermodel.HSSFCell;
    import org.apache.poi.hssf.usermodel.HSSFCellStyle;
    import org.apache.poi.hssf.usermodel.HSSFRow;
    import org.apache.poi.hssf.usermodel.HSSFSheet;
    import org.apache.poi.hssf.usermodel.HSSFWorkbook;
    
    /** * 创建excel，写入数据，然后下载到本地 * * @author baiyu * */
    public class DownloadExcel { 
    
        public static void main(String[] args) {
            Map<String, List<String>> memberMap = getMember();
            String[] strArray = excelTitle();
            ExcelUtil.createExcel(memberMap, strArray);
        }
    
        /** * 初始化数据，将会被存储到excel表格中 * * @return * @throws Exception */
        private static Map<String, List<String>> getMember() {
            List<Member> list = new ArrayList<Member>();
            Map<String, List<String>> map = new HashMap<String, List<String>>();
            SimpleDateFormat df = new SimpleDateFormat("yyyy-mm-dd");
    
            try {
                Member user1 = new Member(1, "熊大", 24, df.parse("1993-08-28"));
                Member user2 = new Member(2, "熊二", 23, df.parse("1994-08-19"));
                Member user3 = new Member(3, "熊熊", 24, df.parse("1983-11-22"));
    
                list.add(user1);
                list.add(user2);
                list.add(user3);
    
                for (int i = 0; i < list.size(); i++) {
                    ArrayList<String> members = new ArrayList<String>();
                    members.add(list.get(i).getCode() + "");
                    members.add(list.get(i).getName());
                    members.add(list.get(i).getAge() + "");
                    members.add(df.format(list.get(i).getBirth()));
                    map.put(list.get(i).getCode() + "", members);
                }
            } catch (ParseException e) {
                e.printStackTrace();
            }
            return map;
        }
    
        /** * 创建excel title */
        public static String[] excelTitle() {
            String[] strArray = { "学号", "姓名", "年龄", "生日" };
            return strArray;
        }
    }

**3. 编写公共的ExcelUtil工具包，用来创建excel，并写入数据，和导入本地**

package com.yu.bai.excel;
    
    import java.io.FileOutputStream;
    import java.util.List;
    import java.util.Map;
    
    import org.apache.poi.hssf.usermodel.HSSFCell;
    import org.apache.poi.hssf.usermodel.HSSFCellStyle;
    import org.apache.poi.hssf.usermodel.HSSFRow;
    import org.apache.poi.hssf.usermodel.HSSFSheet;
    import org.apache.poi.hssf.usermodel.HSSFWorkbook;
    
    public class ExcelUtil {
        /** * @功能：手工构建一个简单格式的Excel */
        public static void createExcel(Map<String, List<String>> map, String[] strArray) {
            // 第一步，创建一个webbook，对应一个Excel文件
            HSSFWorkbook wb = new HSSFWorkbook();
            // 第二步，在webbook中添加一个sheet,对应Excel文件中的sheet
            HSSFSheet sheet = wb.createSheet("sheet1");
            sheet.setDefaultColumnWidth(20);// 默认列宽
            // 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short
            HSSFRow row = sheet.createRow((int) 0);
            // 第四步，创建单元格，并设置值表头 设置表头居中
            HSSFCellStyle style = wb.createCellStyle();
            // 创建一个居中格式
            style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    
            // 添加excel title
            HSSFCell cell = null;
            for (int i = 0; i < strArray.length; i++) { 
                cell = row.createCell((short) i);
                cell.setCellValue(strArray[i]);
                cell.setCellStyle(style);
            }
    
            // 第五步，写入实体数据 实际应用中这些数据从数据库得到,list中字符串的顺序必须和数组strArray中的顺序一致
            int i = 0;
            for (String str : map.keySet()) {
                row = sheet.createRow((int) i + 1);
                List<String> list = map.get(str);
    
                // 第四步，创建单元格，并设置值
                for (int j = 0; j < strArray.length; j++) { 
                    row.createCell((short) j).setCellValue(list.get(j));
                }
    
                // 第六步，将文件存到指定位置
                try {
                    FileOutputStream fout = new FileOutputStream("E:/template/Members.xls");
                    wb.write(fout);
                    fout.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
                i++;
            }
        }
    }

[70]: /images/20220519/c5e1d29fb0e345c3afb6c39e8ef4cff1.png
[70 1]: /images/20220519/1bc214e5d71748fcb0267181a285d953.png