JAVA poi导出为excel详细范例(一)

import java.io.IOException;
import java.io.OutputStream;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.io.IOUtils;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.DataFormat;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public final class ExcelWriter {
public static final class Cell {
private Workbook wb;
private org.apache.poi.ss.usermodel.Cell target;

private Cell(Workbook wb, org.apache.poi.ss.usermodel.Cell cell) {
this.wb = wb;
this.target = cell;
}
public void setCellValue(String value) {
this.target.setCellValue(value);
}
public void setCellValue(Date value) {
if (null == value) {
this.setCellValue("未设置");
return;
}
CellStyle style = this.wb.createCellStyle();
DataFormat format = wb.createDataFormat();
style.setDataFormat(format.getFormat("yyyy/m/d hh:mm:ss"));
this.target.setCellStyle(style);
this.target.setCellValue(value);
}
public void setCellValue(double value) {
CellStyle style = this.wb.createCellStyle();
DataFormat format = wb.createDataFormat();
style.setDataFormat(format.getFormat("###,##0"));
this.target.setCellStyle(style);
this.target.setCellValue(value);
}

public void setCellStyle(CellStyle style){
this.target.setCellStyle(style);
}
}

public static final class Sheet{
private Workbook wb;
private org.apache.poi.ss.usermodel.Sheet sheet;
private Sheet(Workbook wb, org.apache.poi.ss.usermodel.Sheet sheet) {
this.sheet = sheet;
this.wb = wb;
}

public Cell getOrCreateCell(int rowBasedZero, int cellBasedZero) {
Row row = this.sheet.getRow(rowBasedZero);
if (null == row) {
row = this.sheet.createRow(rowBasedZero);
}
return new Cell(this.wb, row.getCell(cellBasedZero, Row.CREATE_NULL_AS_BLANK));
}

//合并单元格
public void mergedRegion(int intFirstRow, int intLastRow, int intFirstColumn, int intLastColumn){
this.sheet.addMergedRegion(new CellRangeAddress(intFirstRow, intLastRow, intFirstColumn, intLastColumn));
}

//添加居中的样式
public CellStyle addStyle(){
CellStyle style = wb.createCellStyle();
style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);// 垂直
style.setAlignment(HSSFCellStyle.ALIGN_CENTER);// 水平
return style;
}

}
private Map sheetMap = new HashMap();
private OutputStream out;
private Workbook wb;

public ExcelWriter(OutputStream out) {
this.out = out;
wb = new XSSFWorkbook();
}

public Sheet getOrCreateSheet(String sheet) {
Sheet sheet1 = this.sheetMap.get(sheet);
if (null != sheet1) {