官网表格行循环: http://deepoove.com/poi-tl/#hack-loop-table

下面展示一些 内联代码片。

创建类工具类：RowspanPolicy

import com.deepoove.poi.data.TextRenderData;
import com.deepoove.poi.policy.HackLoopTableRenderPolicy;
import com.deepoove.poi.util.TableTools;
import org.apache.commons.lang3.reflect.FieldUtils;
import org.apache.poi.xwpf.usermodel.XWPFTable;

import java.util.List;
import java.util.Map;

/**
 * 根据，字段值判断是否合并单元格，
 * Results 泛型传入实体类，
 * 0 为第0列(列下标)
 * “type” 为字段名称
 * 使用方式如下
 * new RowspanPolicy<Results>(0, "type")
 * <p>
 * 仅适需要于用实体类列表循环的表格
 * 循环单元格，改变字体颜色等，为完成
 */
public class RowspanPolicy<T> extends HackLoopTableRenderPolicy {
    private int rowIndex;
    private String fieldName;

    public RowspanPolicy2(boolean onSameLine) {
        this("[", "]", onSameLine, 0, "");
    }

    public RowspanPolicy2(int rowIndex, String fieldName) {
        this("[", "]", false, rowIndex, fieldName);
    }

    public RowspanPolicy2(String prefix, String suffix) {
        this(prefix, suffix, false, 0, "");
    }

    public RowspanPolicy2(String prefix, String suffix, boolean onSameLine, int rowIndex, String fieldName) {
        super(prefix, suffix, onSameLine);
        this.rowIndex = rowIndex;
        this.fieldName = fieldName;
    }

    protected void afterloop(XWPFTable table, Object data) {
        if (null == data) return;
        if (null == fieldName || "".equals(fieldName)) return;
        List<T> list = (List<T>) data;
        String curr = null;
        int count = 0;//重复数量
        for (int i = 0; i < list.size(); i++) {
            String str = getFieldValue(list.get(i), fieldName);
            if (curr == null) {
                curr = str;
                count = 1;
            } else if (curr.equals(str)) {
                ++count;
            } else {
                mergeCellsVertically(table, rowIndex, i, count);
                curr = str;
                count = 1;
            }
        }
        mergeCellsVertically(table, rowIndex, list, count);
    }

    /**
     * 合并行
     *
     * @param rowIndex 列
     * @param index    重复行下标
     * @param count    重复数量
     */
    static void mergeCellsVertically(XWPFTable table, int rowIndex, int index, int count) {
        if (count > 1) TableTools.mergeCellsVertically(table, rowIndex, index - count + 1, index);
    }

    static <T> void mergeCellsVertically(XWPFTable table, int rowIndex, List<T> list, int count) {
        if (count > 1) TableTools.mergeCellsVertically(table, rowIndex, list.size() - count + 1, list.size());
    }

    /**
     * 获取值，判断是重复
     *
     * @param target    数据源
     * @param fieldName 字段名
     * @return 值
     */
    public String getFieldValue(Object target, String fieldName) {
        try {
            if (target instanceof Map) {
                return ((Map<?, ?>) target).get(fieldName).toString();
            }

            Object HSSFCell = FieldUtils.readField(target, fieldName, true);
            if (HSSFCell instanceof String) {
                return (String) HSSFCell;
            }
            TextRenderData textRenderData = (TextRenderData) HSSFCell;
            return textRenderData.getText();
        } catch (IllegalAccessException e) {
            throw new RuntimeException("字段类型不匹配，请检查字段类型和实体类是否一致");
        }
    }
}

应用示例

		//第1列，0为下标需要-1
		//字段名为name
		//TableData： 实体类名称，如果使用的是map 传入map
        RowspanPolicy<TableData> rowspanPolicy = new RowspanPolicy<>(0, "name");
        RowspanPolicy<Map> rowspanPolicy = new RowspanPolicy<>(0, "name");
        Configure.builder().bind("tableData", rowspanPolicy).build();

实现思路：

1.基础原来的循环组件，在循环结束的地方重写 afterloop 方法
2.通过循环判断当前字段是否于上一个字段内容一致，
3.发现不一致的就合并上一组数据，结束时合并未循环的数据

注意

数据合并之前要先按照要合并的列排序
只能合并相邻并且内容一致的数据