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Java工具集-Excel指定文件名称读取工具类
添加依赖
<!--poi-->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.0.1</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.0.1</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml-schemas</artifactId>
<version>4.0.1</version>
</dependency>代码示例
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.URL;
import java.net.URLDecoder;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
* @program: simple_tools
* @description: Excel读取工具类
* @author: Mr.chen
* @create: 2020-04-30 09:55
**/
public class ExcelReader {
private static final String XLS = "xls";
private static final String XLSX = "xlsx";
private static final String ENCODING_TYPE_UTF = "UTF-8";
private static final int ROW_TYPE_FLAG = 0;
private static final int LIST_TYPE_FLAG = 1;
/**
* 读取Excel文件
*
* @param fileName 读取Excel文件的名称
* @param sheetName 读取Excel文件的SheetName
* @return
*/
public static Map<String, Object> readExcel(String fileName, String sheetName) {
FileInputStream inputStream = null;
Workbook workbook = null;
try {
String fileType = fileName.substring(fileName.lastIndexOf(".") + 1);
File excelFile = new File(fileName);
if (!excelFile.exists()) {
System.out.println("the excel file does not exist!");
return null;
}
inputStream = new FileInputStream(excelFile);
workbook = getWorkbook(inputStream, fileType);
return parseExcel(workbook, sheetName);
} catch (Exception e) {
System.out.println(String.format("read excel file throws error :{}",e.getMessage()));
e.printStackTrace();
} finally {
try {
if (workbook != null) workbook.close();
if (inputStream != null) inputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
return null;
}
/**
* 获取一个Excel文件对象
*
* @param inputStream
* @param fileType
* @return
* @throws Exception
*/
private static Workbook getWorkbook(InputStream inputStream, String fileType) throws Exception {
Workbook workbook = null;
if (fileType.equalsIgnoreCase(XLS)) {
workbook = new HSSFWorkbook(inputStream);
} else if (fileType.equalsIgnoreCase(XLSX)) {
workbook = new XSSFWorkbook(inputStream);
}
return workbook;
}
/**
* 解析Excel文件对象
*
* @param workbook
* @param sheetName
* @return
*/
private static Map<String, Object> parseExcel(Workbook workbook, String sheetName) {
Map<String, Object> result = new HashMap<>();
for (int sheetNum = 0; sheetNum < workbook.getNumberOfSheets(); sheetNum++) {
String name = workbook.getSheetName(sheetNum);
if (sheetName == null || sheetName.equals(name)) {
Sheet sheet = workbook.getSheet(name);
result.put(name, convertSheet(sheet));
}
}
return result;
}
/**
* 转换Sheet表为List<Object>集合
*
* @param sheet
* @return
*/
private static List<Object> convertSheet(Sheet sheet) {
List<Object> sheetDataList = new ArrayList<>();
for (int rowNum = 0; rowNum < sheet.getPhysicalNumberOfRows(); rowNum++) {
Row row = sheet.getRow(rowNum);
List<Object> rowDataList = convertRow(row);
sheetDataList.add(rowDataList);
}
return sheetDataList;
}
/**
* 转换行为List<Object>集合
*
* @param row
* @return
*/
private static List<Object> convertRow(Row row) {
List<Object> rowDataList = new ArrayList<>();
for (int cellNum = 0; cellNum < row.getPhysicalNumberOfCells(); cellNum++) {
Cell cell = row.getCell(cellNum);
Object value = convertCell(cell);
rowDataList.add(value);
}
return rowDataList;
}
/**
* 转换每个cell单元格为Object对象
*
* @param cell
* @return
*/
private static Object convertCell(Cell cell) {
CellType cellType = cell.getCellTypeEnum();
Object value = null;
switch (cellType) {
case _NONE:
case BLANK:
case ERROR:
break;
case STRING:
value = cell.getStringCellValue();
break;
case BOOLEAN:
value = cell.getBooleanCellValue();
break;
case NUMERIC:
value = cell.getNumericCellValue();
break;
case FORMULA:
value = cell.getCellFormula();
break;
}
return value;
}
/**
* 读取项目资源目录下 Excel文件
* @param fileName 文件名称
* @param sheetName Excel中的sheet名称
* @return 读取的Map集合
*/
public static Map<String, Object> readExcelFile(String fileName , String sheetName) {
URL resource = ExcelReader.class.getClassLoader().getResource(fileName);
Map<String, Object> result = null;
try {
result = readExcel(URLDecoder.decode(resource.getPath(), ENCODING_TYPE_UTF), sheetName);
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
/**
* 获取Excel文件中的具体值
*
* @param excelMap Excel读取出来的Map结果集
* @param row 需要获取值得行数
* @param list 需要获取值得列数
* @return
*/
public static String getExcelValue(Map<String,Object> excelMap,int row,int list){
// 行数组集合
ArrayList<Object> rowValues = (ArrayList<Object>) excelMap.values();
// 列数组集合
ArrayList<Object> listValues = (ArrayList<Object>) rowValues.get(row);
return String.valueOf(listValues.get(list));
}
/**
* 获取指定列的List集合
*
* @param rowList 行的集合
* @param index 列的索引
* @return
*/
private static List<Object> getLineList(List<Object> rowList, int index){
List<Object> resultList = new ArrayList<>();
Object cell;
for (Object obj : rowList) {
if(obj instanceof ArrayList){
cell = ((ArrayList) obj).get(index);
resultList.add(cell);
}
}
return resultList;
}
/**
* 获取行的集合
*
* @param excelMap
* @return
*/
private static List<Object> getRowList(Map<String, Object> excelMap, int index) {
// 行数组集合
List<Object> resultList = new ArrayList<>();
Iterator<Object> iterator = excelMap.values().iterator();
while(iterator.hasNext()){
Object next = iterator.next();
if(next instanceof ArrayList){
for (Object value : (List<?>)next) {
resultList.add(value);
}
}
}
if (index < 0){
return resultList;
}
Object result = resultList.get(index);
return result instanceof ArrayList ? (List<Object>) result :new ArrayList<>();
}
/**
* 获取Excel文件中指定的一行数据或者是一列数据
*
* @param excelMap 需要进行获取的Excel文件
* @param index 需要获取的一行或者是一列
* @param type 行或者列的类型 0 表示获取行 1 表示获取列
* @return 获取的结果集
*/
public static List<String> getList(Map<String,Object> excelMap,int index,int type){
switch(type){
case ROW_TYPE_FLAG:
return handleRow(excelMap,index);
case LIST_TYPE_FLAG:
return handleList(excelMap,index);
default:return Collections.EMPTY_LIST;
}
}
/**
* 获取Excel中指定列的信息
*
* @param excelMap
* @param index
* @return
*/
private static List<String> handleList(Map<String, Object> excelMap, int index) {
List<Object> rowList = getRowList(excelMap, -1);
List<Object> lineList = getLineList(rowList, index);
List<String> resultList = new ArrayList<>();
for (Object obj : lineList) {
resultList.add(obj.toString());
}
return resultList;
}
/**
* 获取Excel中指定行的信息
*
* @param excelMap
* @param index
* @return
*/
private static List<String> handleRow(Map<String, Object> excelMap, int index) {
List<Object> rowList = getRowList(excelMap, index);
List<String> resultList = new ArrayList<>();
for (Object obj : rowList) {
resultList.add(obj.toString());
}
return resultList;
}
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