使用POI导入和导出Excel文件

最近做试题导入导出，选用了poi导入和导出excel文件，直接用poi的API感觉代码很混乱，耦合度很高，所以封装了两个底层类。一个是ExcelReader：主要包含读取excel内容的方法；另一个是ExcelWriter：主要包含几个生成excel文件的方法。现贴出来供大家以后参考使用：

1、ExcelWriter.java
package com.eruite.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

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.poifs.filesystem.POIFSFileSystem;

/**
* @author caihua
*/
public class ExcelReader {
private HSSFWorkbook wb = null;// book [includes sheet]

private HSSFSheet sheet = null;

private HSSFRow row = null;

private int sheetNum = 0; // 第sheetnum个工作表

private int rowNum = 0;

private FileInputStream fis = null;

private File file = null;

public ExcelReader() {
}

public ExcelReader(File file) {
this.file = file;
}

public void setRowNum(int rowNum) {
this.rowNum = rowNum;
}

public void setSheetNum(int sheetNum) {
this.sheetNum = sheetNum;
}

public void setFile(File file) {
this.file = file;
}

/**
* 读取excel文件获得HSSFWorkbook对象
*/
public void open() throws IOException {
fis = new FileInputStream(file);
wb = new HSSFWorkbook(new POIFSFileSystem(fis));
fis.close();
}

/**
* 返回sheet表数目
*
* @return int
*/
public int getSheetCount() {
int sheetCount = -1;
sheetCount = wb.getNumberOfSheets();
return sheetCount;
}

/**
* sheetNum下的记录行数
*
* @return int
*/
public int getRowCount() {
if (wb == null)
System.out.println("=============>WorkBook为空");
HSSFSheet sheet = wb.getSheetAt(this.sheetNum);
int rowCount = -1;
rowCount = sheet.getLastRowNum();
return rowCount;
}

/**
* 读取指定sheetNum的rowCount
*
* @param sheetNum
* @return int
*/
public int getRowCount(int sheetNum) {
HSSFSheet sheet = wb.getSheetAt(sheetNum);
int rowCount = -1;
rowCount = sheet.getLastRowNum();
return rowCount;
}

/**
* 得到指定行的内容
*
* @param lineNum
* @return String[]
*/
public String[] readExcelLine(int lineNum) {
return readExcelLine(this.sheetNum, lineNum);
}

/**
* 指定工作表和行数的内容
*
* @param sheetNum
* @param lineNum
* @return String[]
*/
public String[] readExcelLine(int sheetNum, int lineNum) {
if (sheetNum < 0 || lineNum < 0)
return null;
String[] strExcelLine = null;
try {
sheet = wb.getSheetAt(sheetNum);
row = sheet.getRow(lineNum);

int cellCount = row.getLastCellNum();
strExcelLine = new String[cellCount + 1];
for (int i = 0; i <= cellCount; i++) {
strExcelLine[i] = readStringExcelCell(lineNum, i);
}
} catch (Exception e) {
e.printStackTrace();
}
return strExcelLine;
}

/**
* 读取指定列的内容
*
* @param cellNum
* @return String
*/
public String readStringExcelCell(int cellNum) {
return readStringExcelCell(this.rowNum, cellNum);
}

/**
* 指定行和列编号的内容
*
* @param rowNum
* @param cellNum
* @return String
*/
public String readStringExcelCell(int rowNum, int cellNum) {
return readStringExcelCell(this.sheetNum, rowNum, cellNum);
}

/**
* 指定工作表、行、列下的内容
*
* @param sheetNum
* @param rowNum
* @param cellNum
* @return String
*/
public String readStringExcelCell(int sheetNum, int rowNum, int cellNum) {
if (sheetNum < 0 || rowNum < 0)
return "";
String strExcelCell = "";
try {
sheet = wb.getSheetAt(sheetNum);
row = sheet.getRow(rowNum);

if (row.getCell((short) cellNum) != null) { // add this condition
// judge
switch (row.getCell((short) cellNum).getCellType()) {
case HSSFCell.CELL_TYPE_FORMULA:
strExcelCell = "FORMULA ";
break;
case HSSFCell.CELL_TYPE_NUMERIC: {
strExcelCell = String.valueOf(row.getCell((short) cellNum)
.getNumericCellValue());
}
break;
case HSSFCell.CELL_TYPE_STRING:
strExcelCell = row.getCell((short) cellNum)
.getStringCellValue();
break;
case HSSFCell.CELL_TYPE_BLANK:
strExcelCell = "";
break;
default:
strExcelCell = "";
break;
}
}
} catch (Exception e) {
e.printStackTrace();
}
return strExcelCell;
}

public static void main(String args[]) {
File file = new File("C://qt.xls");
ExcelReader readExcel = new ExcelReader(file);
try {
readExcel.open();
} catch (IOException e) {
e.printStackTrace();
}
readExcel.setSheetNum(0); // 设置读取索引为0的工作表
// 总行数
int count = readExcel.getRowCount();
for (int i = 0; i <= count; i++) {
String[] rows = readExcel.readExcelLine(i);
for (int j = 0; j < rows.length; j++) {
System.out.print(rows[j] + " ");
}
System.out.print("/n");
}
}
}

2、ExcelWriter.java

package com.eruite.util;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Calendar;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFDataFormat;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

/**
* 生成导出Excel文件对象
*
* @author caihua
*
*/
public class ExcelWriter {
// 设置cell编码解决中文高位字节截断
private static short XLS_ENCODING = HSSFCell.ENCODING_UTF_16;

// 定制浮点数格式
private static String NUMBER_FORMAT = "#,##0.00";

// 定制日期格式
private static String DATE_FORMAT = "m/d/yy"; // "m/d/yy h:mm"

private OutputStream out = null;

private HSSFWorkbook workbook = null;

private HSSFSheet sheet = null;

private HSSFRow row = null;

public ExcelWriter() {
}

/**
* 初始化Excel
*
*/
public ExcelWriter(OutputStream out) {
this.out = out;
this.workbook = new HSSFWorkbook();
this.sheet = workbook.createSheet();
}

/**
* 导出Excel文件
*
* @throws IOException
*/
public void export() throws FileNotFoundException, IOException {
try {
workbook.write(out);
out.flush();
out.close();
} catch (FileNotFoundException e) {
throw new IOException(" 生成导出Excel文件出错! ", e);
} catch (IOException e) {
throw new IOException(" 写入Excel文件出错! ", e);
}

}

/**
* 增加一行
*
* @param index
* 行号
*/
public void createRow(int index) {
this.row = this.sheet.createRow(index);
}

/**
* 获取单元格的值
*
* @param index
* 列号
*/
public String getCell(int index) {
HSSFCell cell = this.row.getCell((short) index);
String strExcelCell = "";
if (cell != null) { // add this condition
// judge
switch (cell.getCellType()) {
case HSSFCell.CELL_TYPE_FORMULA:
strExcelCell = "FORMULA ";
break;
case HSSFCell.CELL_TYPE_NUMERIC: {
strExcelCell = String.valueOf(cell.getNumericCellValue());
}
break;
case HSSFCell.CELL_TYPE_STRING:
strExcelCell = cell.getStringCellValue();
break;
case HSSFCell.CELL_TYPE_BLANK:
strExcelCell = "";
break;
default:
strExcelCell = "";
break;
}
}
return strExcelCell;
}

/**
* 设置单元格
*
* @param index
* 列号
* @param value
* 单元格填充值
*/
public void setCell(int index, int value) {
HSSFCell cell = this.row.createCell((short) index);
cell.setCellType(HSSFCell.CELL_TYPE_NUMERIC);
cell.setCellValue(value);
}

/**
* 设置单元格
*
* @param index
* 列号
* @param value
* 单元格填充值
*/
public void setCell(int index, double value) {
HSSFCell cell = this.row.createCell((short) index);
cell.setCellType(HSSFCell.CELL_TYPE_NUMERIC);
cell.setCellValue(value);
HSSFCellStyle cellStyle = workbook.createCellStyle(); // 建立新的cell样式
HSSFDataFormat format = workbook.createDataFormat();
cellStyle.setDataFormat(format.getFormat(NUMBER_FORMAT)); // 设置cell样式为定制的浮点数格式
cell.setCellStyle(cellStyle); // 设置该cell浮点数的显示格式
}

/**
* 设置单元格
*
* @param index
* 列号
* @param value
* 单元格填充值
*/
public void setCell(int index, String value) {
HSSFCell cell = this.row.createCell((short) index);
cell.setCellType(HSSFCell.CELL_TYPE_STRING);
cell.setEncoding(XLS_ENCODING);
cell.setCellValue(value);
}

/**
* 设置单元格
*
* @param index
* 列号
* @param value
* 单元格填充值
*/
public void setCell(int index, Calendar value) {
HSSFCell cell = this.row.createCell((short) index);
cell.setEncoding(XLS_ENCODING);
cell.setCellValue(value.getTime());
HSSFCellStyle cellStyle = workbook.createCellStyle(); // 建立新的cell样式
cellStyle.setDataFormat(HSSFDataFormat.getBuiltinFormat(DATE_FORMAT)); // 设置cell样式为定制的日期格式
cell.setCellStyle(cellStyle); // 设置该cell日期的显示格式
}

public static void main(String[] args) {
System.out.println(" 开始导出Excel文件 ");

File f = new File("C://qt.xls");
ExcelWriter e = new ExcelWriter();

try {
e = new ExcelWriter(new FileOutputStream(f));
} catch (FileNotFoundException e1) {
e1.printStackTrace();
}

e.createRow(0);
e.setCell(0, "试题编码 ");
e.setCell(1, "题型");
e.setCell(2, "分值");
e.setCell(3, "难度");
e.setCell(4, "级别");
e.setCell(5, "知识点");

e.createRow(1);
e.setCell(0, "t1");
e.setCell(1, 1);
e.setCell(2, 3.0);
e.setCell(3, 1);
e.setCell(4, "重要");
e.setCell(5, "专业");

try {
e.export();
System.out.println(" 导出Excel文件[成功] ");
} catch (IOException ex) {
System.out.println(" 导出Excel文件[失败] ");
ex.printStackTrace();
}
}

}

from:http://www.blogjava.net/caihualin/archive/2008/05/12/164724.html