本篇内容介绍了“Java树形结构数据生成导出excel文件方法是什么”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
String jsonStr = "{\"name\":\"aaa\",\"children\":[{\"name\":\"bbb\",\"children\":[{\"name\":\"eee\"},{\"name\":\"fff\",\"children\":[{\"name\":\"iii\"},{\"name\":\"jjj\",\"children\":[{\"name\":\"qqq\"},{\"name\":\"ttt\"}]}]},{\"name\":\"www\"}]},{\"name\":\"ccc\",\"children\":[{\"name\":\"ggg\"},{\"name\":\"hhh\",\"children\":[{\"name\":\"kkk\",\"children\":[{\"name\":\"ttt\"},{\"name\":\"mmm\"}]},{\"name\":\"uuu\"}]},{\"name\":\"ooo\"}]},{\"name\":\"ddd\",\"children\":[{\"name\":\"ggg\"},{\"name\":\"hhh\",\"children\":[{\"name\":\"kkk\"},{\"name\":\"uuu\"}]}]}]}";
Map tree = JSONObject.parseObject(jsonStr, Map.class);
tree2Excel(tree, "E:\\" + System.currentTimeMillis() + ".xls", "name", "children");package pers.xxx.demo.tree2excel;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.Closeable;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;
import java.util.Map;
/**
* 树形结构数据导出excel工具
* <p>
* Created by lzy on 2021/2/24 14:09
*/
@SuppressWarnings("ALL")
public class Tree2ExcelUtil {
/**
* 树形结构数据生成excel文件
*
* @param tree 树形数据
* @param filePath 文件路径
* @return
*/
public static boolean tree2Excel(Map tree, String filePath) {
return tree2Excel(tree, filePath, null, null);
}
/**
* 树形结构数据生成excel文件
*
* @param tree 树形数据
* @param filePath 文件路径
* @param lableName 标签Key名称
* @param childrenName 子节点Key名称
* @return
*/
public static boolean tree2Excel(Map tree, String filePath, String lableName, String childrenName) {
if (isBlank(filePath)) {
System.err.println("文件名称不能为空");
return false;
}
try {
doSame(tree, lableName, childrenName);
createExcel(filePath, tree);
return true;
} catch (IOException e) {
e.printStackTrace();
}
return false;
}
/**
* 树形结构数据生成Workbook对象
*
* @param tree 树形数据
* @param fileSuf 文件后缀，xls/xlsx
* @return
*/
public static Workbook tree2Worbook(Map tree, String fileSuf) {
return tree2Worbook(tree, fileSuf, null, null);
}
/**
* 树形结构数据生成Workbook对象
*
* @param tree 树形数据
* @param fileSuf 文件后缀，xls/xlsx
* @param lableName 标签Key名称
* @param childrenName 子节点Key名称
* @return
*/
public static Workbook tree2Worbook(Map tree, String fileSuf, String lableName, String childrenName) {
if (isBlank(fileSuf)) {
System.err.println("必须指定文件后缀");
return null;
}
try {
doSame(tree, lableName, childrenName);
return procesData(tree, fileSuf);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
//具体实现
/**
* 标识最大列
*/
private static int maxCol = 0;
private static String lableName = "lable";
private static String childrenName = "children";
private static final String COL = "col";
private static final String ROW = "row";
private static final String ROW_OFT = "rowOft";
private static final String ROW_SIZE = "rowSize";
private static void doSame(Map tree, String lableName, String childrenName) {
if (!isBlank(lableName)) {
Tree2ExcelUtil.lableName = lableName;
}
if (!isBlank(childrenName)) {
Tree2ExcelUtil.childrenName = childrenName;
}
coreAlgoCol(tree, 1);
coreAlgoRow(tree);
}
/**
* 主要算法，计算列的坐标，计算每个节点所占行
*
* @param tree 数据
* @param col 递增的列
* @param trees 把高级别向下传递计算递增的行高
*/
private static void coreAlgoCol(Map tree, int col, Map... trees) {
tree.put(COL, col);
Object childrenObj = tree.get(childrenName);
if (childrenObj != null) {
List<Map> children = (List<Map>) childrenObj;
if (children.size() > 0) {
int size = children.size() * 2 - 1;
tree.put(ROW_SIZE, size);
int len = trees != null ? trees.length + 1 : 1;
Map[] arrData = new Map[len];
if (trees != null && trees.length > 0) {
for (int i = 0; i < trees.length; i++) {
Map tree1 = trees[i];
tree1.put(ROW_SIZE, toInt(tree1.get(ROW_SIZE), 1) + size - 1);
arrData[i] = tree1;
}
}
arrData[len - 1] = tree;
for (Map tree1 : children) {
int newCol = col + 1;
if (newCol > maxCol) {
maxCol = newCol;
}
coreAlgoCol(tree1, newCol, arrData);
}
}
}
}
/**
* 主要算法，计算行的坐标
*
* @param tree
*/
private static void coreAlgoRow(Map tree) {
if (toInt(tree.get(ROW)) == 0) {
tree.put(ROW, Math.round(toInt(tree.get(ROW_SIZE), 1) / 2.0f));
}
Object childrenObj = tree.get(childrenName);
if (childrenObj != null) {
List<Map> children = (List<Map>) childrenObj;
if (children.size() > 0) {
int tempOft = toInt(tree.get(ROW_OFT));
for (Map tree1 : children) {
int rowSize = toInt(tree1.get(ROW_SIZE), 1);
tree1.put(ROW_OFT, tempOft);
tree1.put(ROW, tempOft + Math.round(rowSize / 2.0f));
tempOft += rowSize + 1;
coreAlgoRow(tree1);
}
}
}
}
/**
* 创建excel文件
*
* @param filePath 文件路径，具体路径到文件名
* @param tree 数据
* @throws IOException
*/
private static void createExcel(String filePath, Map tree) throws IOException {
File file = new File(filePath);
boolean bfile = file.createNewFile();
// 复制模板到新文件
if (bfile) {
Workbook wk = procesData(tree, filePath);
if (wk != null) {
FileOutputStream fos = null;
try {
fos = new FileOutputStream(file);
wk.write(fos);
fos.flush();
} finally {
closeStream(fos);
wk.close();
}
}
}
}
/**
* 处理excel数据
*
* @param tree 数据
* @return 工作表对象
*/
private static Workbook procesData(Map tree, String fileName) {
Workbook wk = null;
if (fileName.endsWith("xls")) {
wk = new HSSFWorkbook();
}
if (fileName.endsWith("xlsx")) {
wk = new XSSFWorkbook();
}
if (wk == null) {
System.err.println("文件名称不正确");
return null;
}
//创建一个sheet页
Sheet sheet = wk.createSheet("Sheet1");
int colSize = maxCol * 2 + 2;
int rowSize = toInt(tree.get(ROW_SIZE), 1);
for (int i = 0; i <= rowSize; i++) {
Row row = sheet.createRow(i);
for (int j = 0; j <= colSize; j++) {
row.createCell(j);
}
}
//配置单元格背景色
CellStyle style1 = wk.createCellStyle();
style1.setFillForegroundColor(IndexedColors.LIGHT_GREEN.getIndex());
style1.setFillPattern(FillPatternType.SOLID_FOREGROUND);
CellStyle style2 = wk.createCellStyle();
style2.setFillForegroundColor(IndexedColors.LIGHT_YELLOW.getIndex());
style2.setFillPattern(FillPatternType.SOLID_FOREGROUND);
dealCell(sheet, tree, style1, style2);
return wk;
}
/**
* 根据计算好的坐标填充每一个单元格
*
* @param sheet #
* @param tree 数据
* @param style1 单元格格式
* @param style2 单元格格式
*/
private static void dealCell(Sheet sheet, Map tree, CellStyle style1, CellStyle style2) {
Row row = sheet.getRow(toInt(tree.get(ROW)));
int oftCol = (toInt(tree.get(COL)) - 1) * 2 + 1;
Cell cell = row.getCell(oftCol);
cell.setCellStyle(style1);
cell.setCellValue(String.valueOf(tree.get(lableName)));
sheet.setColumnWidth(oftCol, 256 * 20);
Object childrenObj = tree.get(childrenName);
if (childrenObj != null) {
List<Map> children = (List<Map>) childrenObj;
if (children.size() > 0) {
int size = children.size();
int startRow = toInt(children.get(0).get(ROW));
int endRow = toInt(children.get(size - 1).get(ROW));
int col = oftCol + 1;
sheet.setColumnWidth(col, 256);
for (; startRow <= endRow; startRow++) {
sheet.getRow(startRow).getCell(col).setCellStyle(style2);
}
for (Map child : children) {
dealCell(sheet, child, style1, style2);
}
}
}
}
private static int toInt(Object val) {
return toInt(val, 0);
}
private static int toInt(Object val, Integer defVal) {
try {
return Integer.parseInt(String.valueOf(val));
} catch (NumberFormatException ignored) {
}
return defVal;
}
private static boolean isBlank(String str) {
return str == null || str.trim().length() == 0;
}
/**
* 关闭流
*
* @param closeables 不定长数组 流对象
*/
public static void closeStream(Closeable... closeables) {
for (Closeable closeable : closeables) {
if (closeable != null) {
try {
closeable.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}“Java树形结构数据生成导出excel文件方法是什么”的内容就介绍到这里了，感谢大家的阅读。如果想了解更多行业相关的知识可以关注亿速云网站，小编将为大家输出更多高质量的实用文章！
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