需求来源
最近幼儿园老师总在要求家长给孩子出10以内的合成分解题目，类似这个：
就很麻烦所以想到能不能写个代码直接生成题目，然后打印出来给他做就好了，方便快捷，想到就做
实现方案
实现方式也很简单，题目很规整可以直接放Excel文件里，直接用Apache POI操作单元格即可，思路就这么几步：
根据A4纸的长款规划好单元格的大小以及题目的个数
随机生成一个10以内的随机数n，然后生成一个n以内的随机数a，10 - a得到b，这样一道题目的3个数得到了
生成步骤2这样的50道题目，然后循环将题目输出到Excel即可
具体代码如下：
import cn.hutool.core.util.RandomUtil;
import lombok.Data;
import org.apache.poi.ss.usermodel.BorderStyle;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class Main {
public static void main(String[] args) throws Exception {
XSSFWorkbook workbook = new XSSFWorkbook();
XSSFSheet sheet = workbook.createSheet();
// 准备好各个单元格需要用到的样式
CellStyle cellStyleOne = workbook.createCellStyle();
cellStyleOne.setAlignment(HorizontalAlignment.LEFT);
CellStyle cellStyleTwo = workbook.createCellStyle();
cellStyleTwo.setAlignment(HorizontalAlignment.RIGHT);
CellStyle cellStyleTotal = workbook.createCellStyle();
cellStyleTotal.setAlignment(HorizontalAlignment.CENTER);
CellStyle cellStyleNull = workbook.createCellStyle();
cellStyleNull.setBorderBottom(BorderStyle.THIN);
cellStyleNull.setBorderTop(BorderStyle.THIN);
cellStyleNull.setBorderLeft(BorderStyle.THIN);
cellStyleNull.setBorderRight(BorderStyle.THIN);
// 设置所有单元格的宽度
for (int i = 0; i < 32; i++) {
sheet.setColumnWidth(i, 700);
}
// 一次创建24行44列的单元格，放在Map里方便后续调用
Map<String, XSSFCell> cellMap = new HashMap<>();
for (int i = 0; i < 48; i++) {
XSSFRow row = sheet.createRow(i);
row.setHeight((short) 300);
for (int j = 0; j < 32; j++) {
XSSFCell cell = row.createCell(j);
cellMap.put(i + "," + j, cell);
}
}
// 生成50道题目
List<Topic> topicList = Topic.createTopic(120, max);
int index = 0;
for (int i = 0; i < 12; i++) {
for (int j = 0; j < 8; j++) {
Topic topic = topicList.get(index++);
if (topic.getType() == 0) {
// 生成合成题
XSSFCell cell1 = cellMap.get((i * 4) + "," + (j * 4));
cell1.setCellValue(topic.getOne());
cell1.setCellStyle(cellStyleOne);
XSSFCell cell2 = cellMap.get((i * 4) + "," + (j * 4 + 2));
cell2.setCellValue(topic.getTwo());
cell2.setCellStyle(cellStyleTwo);
XSSFCell cell3 = cellMap.get((i * 4 + 2) + "," + (j * 4 + 1));
cell3.setCellValue(topic.getTotal());
cell3.setCellStyle(cellStyleTotal);
XSSFCell cell4 = cellMap.get((i * 4 + 1) + "," + (j * 4 ));
cell4.setCellValue("\\");
cell4.setCellStyle(cellStyleTwo);
XSSFCell cell5 = cellMap.get((i * 4 + 1) + "," + (j * 4 + 2));
cell5.setCellValue("/");
cell5.setCellStyle(cellStyleOne);
// 随机将3个数值单元格中的一个清空作为题目
switch (topic.getNullPosition()) {
case 0:
cell3.setCellValue("");
cell3.setCellStyle(cellStyleNull);
break;
case 1:
cell1.setCellValue("");
cell1.setCellStyle(cellStyleNull);
break;
case 2:
cell2.setCellValue("");
cell2.setCellStyle(cellStyleNull);
break;
}
} else {
// 生成分解题
XSSFCell cell1 = cellMap.get((i * 4 + 2) + "," + (j * 4));
cell1.setCellValue(topic.getOne());
cell1.setCellStyle(cellStyleOne);
XSSFCell cell2 = cellMap.get((i * 4 + 2) + "," + (j * 4 + 2));
cell2.setCellValue(topic.getTwo());
cell2.setCellStyle(cellStyleTwo);
XSSFCell cell3 = cellMap.get((i * 4) + "," + (j * 4 + 1));
cell3.setCellValue(topic.getTotal());
cell3.setCellStyle(cellStyleTotal);
XSSFCell cell4 = cellMap.get((i * 4 + 1) + "," + (j * 4));
cell4.setCellValue("/");
cell4.setCellStyle(cellStyleTwo);
XSSFCell cell5 = cellMap.get((i * 4 + 1) + "," + (j * 4 + 2));
cell5.setCellValue("\\");
cell5.setCellStyle(cellStyleOne);
// 随机将3个数值单元格中的一个清空作为题目
switch (topic.getNullPosition()) {
case 0:
cell3.setCellValue("");
cell3.setCellStyle(cellStyleNull);
break;
case 1:
cell1.setCellValue("");
cell1.setCellStyle(cellStyleNull);
break;
case 2:
cell2.setCellValue("");
cell2.setCellStyle(cellStyleNull);
break;
}
}
}
}
// 输出文件
try (OutputStream os = Files.newOutputStream(Paths.get("/Users/chengpei/Desktop/test.xlsx"))) {
workbook.write(os);
} catch (Exception e) {
e.printStackTrace();
} finally {
workbook.close();
}
}
@Data
public static class Topic {
/**
* 0-合并 1-分解
*/
private int type;
/**
* 0-空总值 1-空左值 2-空又值
*/
private int nullPosition;
private int one;
private int two;
private int max;
private int getTotal() {
return one + two;
}
public static List<Topic> createTopic(int n, int max) {
List<Topic> list = new ArrayList<>();
for (int i = 0; i < n; i++) {
list.add(createTopic(max));
}
return list;
}
public static Topic createTopic(int max) {
Topic topic = new Topic();
topic.setMax(max);
int total = RandomUtil.randomInt(3, max + 1);
topic.setOne(RandomUtil.randomInt(1, total));
topic.setTwo(total - topic.getOne());
topic.setNullPosition(RandomUtil.randomInt(0, 3));
topic.setType(RandomUtil.randomInt(0, 2));
return topic;
}
}
}主要就用到了以下两个依赖：
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
<version>5.5.1</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>5.2.2</version>
</dependency>一个hutool用来生成随机数，一个poi用来操作生成Excel文件，生成的文件打印预览效果如图：
如果只是需要题目可以在我的博客(https://www.chengpei.top/)直接下载随机的题目Excel，首页-常用工具-下载合成分解练习题即可下载到
评论区