【Apache POI】Java 读取Excel文件

àì夳堔傛蜴生んèń 2022-09-30 11:48 289阅读 0赞

**Excel内容如下：**

![Center][]

**封装Excel行列字段的Bean：**

public class Employee {
    	
    	private String name;
    	private String gender;
    	private int age;
    	private String department;
    	private double salary;
    	/**
    	 * 注意：读取日期操作要将Excel单元格设为文本格式，然后按字符串读取；写入操作时，直接按字符串写入
    	 */
    	private String date;
    	public Employee() {
    		super();
    	}
    	public Employee(String name, String gender, int age, String department,
    			double salary, String date) {
    		super();
    		this.name = name;
    		this.gender = gender;
    		this.age = age;
    		this.department = department;
    		this.salary = salary;
    		this.date = date;
    	}
    	//省略getter/setter方法
    	@Override
    	public String toString() {
    		return "Employee [name=" + name + ", gender=" + gender + ", age=" + age
    				+ ", department=" + department + ", salary=" + salary
    				+ ", date=" + date + "]";
    	}
    }

**读取Excel文件的方法：**

import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.ArrayList;
    import java.util.Iterator;
    import java.util.List;
    import org.apache.poi.hssf.usermodel.HSSFCell;
    import org.apache.poi.hssf.usermodel.HSSFRow;
    import org.apache.poi.hssf.usermodel.HSSFSheet;
    import org.apache.poi.hssf.usermodel.HSSFWorkbook;
    import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
    import org.apache.poi.ss.usermodel.Cell;
    import org.apache.poi.ss.usermodel.Row;
    import org.apache.poi.ss.usermodel.Sheet;
    import org.apache.poi.ss.usermodel.Workbook;
    import org.apache.poi.ss.usermodel.WorkbookFactory;
    import com.lmb.excel.bean.Employee;
    
    /**
     * 读取Excel文件的方法
     * @author lmb
     * @date 2017-3-15
     *
     */
    public class ReadExcel {
    
    	private static String xls2003 = "D:\\employee.xls";
    	private static String xlsx2007 = "D:\\employee.xlsx";
    	
    	/** 
         * 读取Excel2003的主表数据 （单个sheet）
         * @param filePath 
         * @return 
         */  
    	private static List<Employee> readFromXLS2003(String filePath) {  
            File excelFile = null;// Excel文件对象  
            InputStream is = null;// 输入流对象  
            String cellStr = null;// 单元格，最终按字符串处理  
            List<Employee> employeeList = new ArrayList<Employee>();// 返回封装数据的List  
            Employee employee = null;// 每一个雇员信息对象  
            try {  
                excelFile = new File(filePath);  
                is = new FileInputStream(excelFile);// 获取文件输入流  
                HSSFWorkbook workbook2003 = new HSSFWorkbook(is);// 创建Excel2003文件对象  
                HSSFSheet sheet = workbook2003.getSheetAt(0);// 取出第一个工作表，索引是0  
                // 开始循环遍历行，表头不处理，从1开始  
                for (int i = 1; i <= sheet.getLastRowNum(); i++) {  
                	HSSFRow row = sheet.getRow(i);// 获取行对象 
                	employee = new Employee();// 实例化Student对象  
                    if (row == null) {// 如果为空，不处理  
                        continue;  
                    }  
                    // 循环遍历单元格  
                    for (int j = 0; j < row.getLastCellNum(); j++) {  
                        HSSFCell cell = row.getCell(j);// 获取单元格对象  
                        if (cell == null) {// 单元格为空设置cellStr为空串  
                            cellStr = "";  
                        } else if (cell.getCellType() == HSSFCell.CELL_TYPE_BOOLEAN) {// 对布尔值的处理  
                            cellStr = String.valueOf(cell.getBooleanCellValue());  
                        } else if (cell.getCellType() == HSSFCell.CELL_TYPE_NUMERIC) {// 对数字值的处理  
                            cellStr = cell.getNumericCellValue() + "";
                        } else {// 其余按照字符串处理  
                            cellStr = cell.getStringCellValue();  
                        }  
                        // 下面按照数据出现位置封装到bean中  
                        if (j == 0) {  
                        	employee.setName(cellStr);  
                        } else if (j == 1) {  
                        	employee.setGender(cellStr);  
                        } else if (j == 2) {  
                        	employee.setAge(new Double(cellStr).intValue());  
                        } else if (j == 3) {  
                        	employee.setDepartment(cellStr);  
                        } else if(j == 4){  
                        	employee.setSalary(new Double(cellStr).intValue());  
                        }else {  
                        	employee.setDate(cellStr);  
                        }  
                    }  
                    employeeList.add(employee);// 数据装入List  
                }  
    		} catch (IOException e) {  
                e.printStackTrace();  
            } finally {// 关闭文件流  
                if (is != null) {  
                    try {  
                        is.close();  
                    } catch (IOException e) {  
                        e.printStackTrace();  
                    }  
                }  
            }  
            return employeeList;  
        }  
    	
    	/**
    	 * 读取Excel2003的表头
    	 * @param filePath 需要读取的文件路径
    	 * @return
    	 */
    	public static String[] readHeaderFromXLS2003(String filePath){
    		String[] excelTitle = null;
    		FileInputStream is = null;
    		try{
    			File excelFile = new File(filePath);
    			is = new FileInputStream(excelFile);
    			HSSFWorkbook workbook2003 = new HSSFWorkbook(is);
    			//循环读取工作表
    			for (int i = 0; i < workbook2003.getNumberOfSheets(); i++) {
    				 HSSFSheet hssfSheet = workbook2003.getSheetAt(i);			 
    				//*************获取表头是start*************
    		            HSSFRow sheetRow = hssfSheet.getRow(i);  
    		            excelTitle = new String[sheetRow.getLastCellNum()];
    		            for (int k = 0; k < sheetRow.getLastCellNum(); k++) {
    		            	HSSFCell hssfCell = sheetRow.getCell(k);
    		            	excelTitle[k] = hssfCell.getStringCellValue();
    //		            	System.out.println(excelTitle[k] + " ");
    		            }
    		    		//*************获取表头end*************
    			}
    		}catch (IOException e) {  
                e.printStackTrace();  
            } finally {// 关闭文件流  
                if (is != null) {  
                    try {  
                        is.close();  
                    } catch (IOException e) {  
                        e.printStackTrace();  
                    }  
                }  
            }  		
    		return excelTitle;
    	}
    	
    	/**
    	 * 读取Excel2007的示例方法 （单个sheet）
    	 * @param filePath
    	 * @return
    	 */
    	public static List<Employee> readFromXLSX2007(String filePath) {  
            File excelFile = null;// Excel文件对象  
            InputStream is = null;// 输入流对象  
            String cellStr = null;// 单元格，最终按字符串处理  
            List<Employee> studentList = new ArrayList<Employee>();// 返回封装数据的List  
            Employee employee = null;// 每一个雇员信息对象  
            try {  
                excelFile = new File(filePath);  
                is = new FileInputStream(excelFile);// 获取文件输入流  
    //            XSSFWorkbook workbook2007 = new XSSFWorkbook(is);// 创建Excel2007文件对象
                org.apache.poi.ss.usermodel.Workbook workbook2007 = WorkbookFactory.create(is);
    //            XSSFSheet sheet = workbook2007.getSheetAt(0);// 取出第一个工作表，索引是0 
                org.apache.poi.ss.usermodel.Sheet sheet = workbook2007.getSheetAt(0);
                // 开始循环遍历行，表头不处理，从1开始  
                for (int i = 1; i <= sheet.getLastRowNum(); i++) {  
                	employee = new Employee();// 实例化Student对象  
    //            	HSSFRow row = sheet.getRow(i);// 获取行对象 
                	Row row = sheet.getRow(i);// 获取行对象  
                    if (row == null) {// 如果为空，不处理
                        continue;  
                    }  
                    // 循环遍历单元格  
                    for (int j = 0; j < row.getLastCellNum(); j++) {  
    //                    XSSFCell cell = row.getCell(j);// 获取单元格对象 
                    	Cell cell = row.getCell(j);// 获取单元格对象 
                        if (cell == null) {// 单元格为空设置cellStr为空串  
                            cellStr = "";  
                        } else if (cell.getCellType() == HSSFCell.CELL_TYPE_BOOLEAN) {// 对布尔值的处理  
                            cellStr = String.valueOf(cell.getBooleanCellValue());  
                        } else if (cell.getCellType() == HSSFCell.CELL_TYPE_NUMERIC) {// 对数字值的处理  
                            cellStr = cell.getNumericCellValue() + "";  
                        } else {// 其余按照字符串处理  
                            cellStr = cell.getStringCellValue();  
                        }  
                        // 下面按照数据出现位置封装到bean中  
                        if (j == 0) {  
                        	employee.setName(cellStr);  
                        } else if (j == 1) {  
                        	employee.setGender(cellStr);  
                        } else if (j == 2) {  
                        	employee.setAge(new Double(cellStr).intValue());  
                        } else if (j == 3) {  
                        	employee.setDepartment(cellStr);  
                        } else if(j == 4){  
                        	employee.setSalary(new Double(cellStr).intValue());  
                        } else {  
                        	employee.setDate(cellStr);  
                        }  
                    }  
                    studentList.add(employee);// 数据装入List  
                }  
            } catch (IOException e) {  
                e.printStackTrace();  
            } catch (InvalidFormatException e) {
    			// TODO Auto-generated catch block
    		}finally {// 关闭文件流  
                if (is != null) {  
                    try {  
                        is.close();  
                    } catch (IOException e) {  
                        e.printStackTrace();  
                    }  
                }  
            }  
            return studentList;  
        }  
    	
    	/**
    	 * 读取Excel的示例方法 （多个sheet）
    	 * @param filePath
    	 * @return
    	 */
    	public List<Employee> readMoreSheetFromXLS(String filePath){
    		List<Employee> employeeList = new ArrayList<Employee>();
    		String cellStr = null;//单元格，最终按字符串处理
    		//创建来自excel文件的输入流
    		try {
    			FileInputStream is = new FileInputStream(filePath);
    			//创建WorkBook实例
    			Workbook workbook = null;
    			if (filePath.toLowerCase().endsWith("xls")) {//2003
    				workbook = new HSSFWorkbook(is);
    			}else if(filePath.toLowerCase().endsWith("xlsx")){//2007
    				workbook = WorkbookFactory.create(is);
    			}
    			//获取excel文件的sheet数量
    			int numOfSheets = workbook.getNumberOfSheets();
    			//挨个遍历sheet
    			for (int i = 0; i < numOfSheets; i++) {
    				Sheet sheet = workbook.getSheetAt(i);
    				//挨个遍历sheet的每一行
    				for (Iterator<Row> iterRow = sheet.iterator();iterRow.hasNext();) {
    					Row row = iterRow.next();
    					Employee employee = new Employee();
    					int j = 0;//标识位，用于标识第几列
    					//挨个遍历每一行的每一列
    					for (Iterator<Cell> cellIter = row.cellIterator();cellIter.hasNext();) {
    						Cell cell = cellIter.next();//获取单元格对象
    						if (j == 0) {
    							if (cell == null) {// 单元格为空设置cellStr为空串  
    		                        cellStr = "";  
    		                    } else if (cell.getCellType() == HSSFCell.CELL_TYPE_BOOLEAN) {// 对布尔值的处理  
    		                        cellStr = String.valueOf(cell.getBooleanCellValue());  
    		                    } else if (cell.getCellType() == HSSFCell.CELL_TYPE_NUMERIC) {// 对数字值的处理  
    		                        cellStr = cell.getNumericCellValue() + "";  
    		                    } else {// 其余按照字符串处理  
    		                        cellStr = cell.getStringCellValue();  
    		                    }  
    							employee.setName(cellStr); 
    							j ++;
    						}
    //						employee.setGender(cellStr); j == 1
    //						employee.setAge(new Double(cellStr).intValue()); j == 2
    //						employee.setDepartment(cellStr); j == 3
    //						employee.setSalary(new Double(cellStr).intValue());  j == 4
    //						employee.setDate(cellStr); j == 5
    						employeeList.add(employee);
    					}
    				}
    			}
    		} catch (FileNotFoundException e) {
    			e.printStackTrace();
    		} catch (IOException e) {
    			e.printStackTrace();
    		} catch (InvalidFormatException e) {
    			e.printStackTrace();
    		}
    		return employeeList;
    	}
    	
    	/** 
         * 主函数 
         *  
         * @param args 
         */  
        public static void main(String[] args) {  
        	System.out.println("************读取Excel2003的主表数据（将Excel单元格设为文本格式）******************");
            long start2003 = System.currentTimeMillis();  
            List<Employee> list2003 = readFromXLS2003(xls2003);  
            for (Employee employee : list2003) {  
                System.out.println(employee);  
            }  
            long end2003 = System.currentTimeMillis();  
            System.out.println((end2003 - start2003) + " ms done!");  
            System.out.println("***********读取Excel2007的主表数据（未将Excel单元格设为文本格式） *********************");
            long start2007 = System.currentTimeMillis();  
            List<Employee> list2007 = readFromXLSX2007(xlsx2007);  
            for (Employee employee : list2007) {  
                System.out.println(employee);  
            }
            long end2007 = System.currentTimeMillis();  
            System.out.println((end2007 - start2007) + " ms done!");  
            System.out.println("************读取Excel2003的表头**********************");
            String[] excelTitle = readHeaderFromXLS2003(xls2003);
            StringBuffer title = new StringBuffer(); 
            for (int i = 0; i < excelTitle.length; i++) {
    			title.append(excelTitle[i] + " ");
    		}
            System.out.println(title.toString());
        }  
        
        /*	运行结果：http://stackoverflow.com/questions/21992071/org-apache-poi-poixmlexception-org-apache-poi-openxml4j-exceptions-invalidforma
            ************读取Excel2003的主表数据（将Excel单元格设为文本格式）******************
    		Employee [name=Tom, gender=男, age=29, department=信息技术部, salary=6800.0, date=20170316]
    		Employee [name=Jack, gender=男, age=25, department=质量保障部, salary=6800.0, date=20170316]
    		Employee [name=May, gender=女, age=26, department=公共关系部, salary=6800.0, date=20170316]
    		Employee [name=Mary, gender=女, age=27, department=财务部, salary=6800.0, date=20170316]
    		Employee [name=Sarah, gender=女, age=28, department=电销部, salary=6800.0, date=20170316]
    		268 ms done!
         	***********读取Excel2007的主表数据 （未将Excel单元格设为文本格式）*********************
    		Employee [name=Tom, gender=男, age=29, department=信息技术部, salary=6800.0, date=42810.0]
    		Employee [name=Jack, gender=男, age=25, department=质量保障部, salary=6800.0, date=42810.0]
    		Employee [name=May, gender=女, age=26, department=公共关系部, salary=6800.0, date=42810.0]
    		Employee [name=Mary, gender=女, age=27, department=财务部, salary=6800.0, date=42810.0]
    		Employee [name=Sarah, gender=女, age=28, department=电销部, salary=6800.0, date=42810.0]
    		924 ms done!
         	************读取Excel2003的表头**********************
    		姓名 性别 年龄 部门 薪资 日期 
        */
    }

以上方法分为对Excel正文的读取和对Excel表头的读取，注释写的很详细，我就不在多说什么，大家参看具体实现。

**需要特别说明一点：**

读取日期操作要将Excel单元格设为文本格式，然后程序中按字符串读取；写入操作时，程序内也直接按字符串写入。否则读取到的日期内容是有问题的，参看上面的日志打印结果。  
**将Excel单元格设为文本格式的方法如下：**

![Center 1][]

![Center 2][]

![Center 3][]

[Center]: /images/20220706/91f39424ed3a4b5f8d96e4f47a2bd7a1.png
[Center 1]: /images/20220706/bb8d5b0459e548809f6b47da026c6dd4.png
[Center 2]: /images/20220706/3885e433081944aeb43a4551eaf93383.png
[Center 3]: /images/20220706/68b4aacc1ac74e9793bce99790caca24.png