好了,先分享日本语讲座第一课吧.

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setFont
public void setFont(HSSFFont font)

set the font for this style 

Parameters:
  font - a font object created or retreived
from the HSSFWorkbook object

参数是表示字体的「HSSFFont」类对象。关于「HSSFFont」类的定义，详见如下：

HSSFFont类定义

虽然有一个构造方法，但仍然是protected的，还是不能直接使用。必须通过「HSSFWorkbook」类的「createFont」方法来生成。

createFont
public HSSFFont createFont()

create a new Font and add it to the workbook's font table 

Returns:
  new font object

使用方法如下：

HSSFWorkbook workbook = new HSSFWorkbook();

HSSFFont font = workbook.createFont();
HSSFCellStyle style = workbook.createCellStyle();

style.setFont(font);

字体的指定

下面就具体看看如何设定字体。指定字体使用「HSSFFont」类的「setFontName」方法。

setFontName
public void setFontName(java.lang.String name)

set the name for the font (i.e. Arial) 

Parameters:
  name - String representing the name of the font to use

参数是字体名称。如「Arial Black」和「华文彩云」等。另外还有一点要说明的是，如果你要设置中文字体，那必须还要再对单元格进行编码设置

(font.setCharSet(HSSFFont.DEFAULT_CHARSET))，否则无效。

示例程序

实际动手做做看吧。

import java.io.*;

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

public class POISample{
  public static void main(String[] args){
    HSSFWorkbook workbook = new HSSFWorkbook();

    HSSFSheet sheet = workbook.createSheet();

    HSSFRow row0 = sheet.createRow(0);
    HSSFCell cell0 = row0.createCell(1);

    HSSFCellStyle style0 = workbook.createCellStyle();
    HSSFFont font0 = workbook.createFont();
    font0.setFontName("Arial Black");
    style0.setFont(font0);
    cell0.setCellStyle(style0);
    cell0.setCellValue(new HSSFRichTextString("Arial Black"));

    HSSFRow row1 = sheet.createRow(1);
    HSSFCell cell1 = row1.createCell(1);

    HSSFCellStyle style1 = workbook.createCellStyle();
    HSSFFont font1 = workbook.createFont();
    font1.setFontName("华文彩云");
    font1.setCharSet(HSSFFont.DEFAULT_CHARSET);
    style1.setFont(font1);
    cell1.setCellStyle(style1);
    cell1.setCellValue(new HSSFRichTextString("华文彩云"));

    HSSFRow row2 = sheet.createRow(2);
    HSSFCell cell2 = row2.createCell(1);

    HSSFCellStyle style2 = workbook.createCellStyle();
    HSSFFont font2 = workbook.createFont();
    font2.setFontName("隶书");
    font2.setCharSet(HSSFFont.DEFAULT_CHARSET);
    style2.setFont(font2);
    cell2.setCellStyle(style2);
    cell2.setCellValue(new HSSFRichTextString("隶书"));

    HSSFRow row3 = sheet.createRow(3);
    HSSFCell cell3 = row3.createCell(1);

    HSSFCellStyle style3 = workbook.createCellStyle();
    HSSFFont font3 = workbook.createFont();
    font3.setFontName("华文行楷");
    //font3.setCharSet(HSSFFont.DEFAULT_CHARSET);
    style3.setFont(font3);
    cell3.setCellStyle(style3);
    cell3.setCellValue(new HSSFRichTextString("华文行楷"));

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }
}

运行结果如下：

另外，要取得可以指定的字体，最简单的方法就是，打开Excel文件，从字体选择的地方直接复制过来就可以了。

首先是边框的位置和种类。对单元格设置边框时，有上下左右位置之分，所以POI也准备了四个不同的方法。

上部的边框：

setBorderTop
public void setBorderTop(short border)

set the type of border to use for the top
border of the cell 

Parameters:
  border - type

下部的边框：

setBorderBottom
public void setBorderBottom(short border)

set the type of border to use for the
bottom border of the cell 

Parameters:
  border - type

左侧的边框：

setBorderLeft
public void setBorderLeft(short border)

set the type of border to use for the
left border of the cell 

Parameters:
  border - type

右侧的边框：

setBorderRight
public void setBorderRight(short border)

set the type of border to use for the
right border of the cell 

Parameters:
  border - type

参数通过表示边框种类的short型值来指定。下面是定义在「HSSFCellStyle」类里可以被指定值的一览表。

比如要在单元格下边框设置两重线的边框时，按如下方法：

HSSFWorkbook workbook = new HSSFWorkbook();

HSSFCellStyle style = workbook.createCellStyle();
style.setBorderRight(HSSFCellStyle.BORDER_THIN);

下面再看看指定边框顔色。同样也分为上下左右边框来操作。

上部的边框：

setTopBorderColor
public void setTopBorderColor(short color)

set the color to use for the top border 

Parameters:
  color -

下部的边框：

setBottomBorderColor
public void setBottomBorderColor(short color)

set the color to use for the bottom border 

Parameters:
  color -

左侧的边框：

setLeftBorderColor
public void setLeftBorderColor(short color)

set the color to use for the left border 

Parameters:
  color -

右侧的边框：

setRightBorderColor
public void setRightBorderColor(short color)

set the color to use for the right border 

Parameters:
  color -

仍然是通过参数来指定顔色，而且使用方法和前面一节也是一样。具体如下：

HSSFWorkbook workbook = new HSSFWorkbook();

HSSFCellStyle style = workbook.createCellStyle();
style.setRightBorderColor(HSSFColor.RED.index);
style.setBorderRight(HSSFCellStyle.BORDER_THIN);

示例程序

实际动手做做吧。首先看看如何设置上下左右的边框。

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.hssf.usermodel.HSSFPalette;

public class POISample{
  public static void main(String[] args){
    HSSFWorkbook workbook = new HSSFWorkbook();
    HSSFSheet sheet = workbook.createSheet();

    HSSFRow row = sheet.createRow(1);
    HSSFCell cell1 = row.createCell((short)1);
    HSSFCell cell2 = row.createCell((short)2);

    HSSFCellStyle style1 = workbook.createCellStyle();
    style1.setBorderTop(HSSFCellStyle.BORDER_DOUBLE);
    style1.setBorderLeft(HSSFCellStyle.BORDER_DOUBLE);
    style1.setTopBorderColor(HSSFColor.GOLD.index);
    style1.setLeftBorderColor(HSSFColor.PLUM.index);
    cell1.setCellStyle(style1);

    HSSFCellStyle style2 = workbook.createCellStyle();
    style2.setBorderBottom(HSSFCellStyle.BORDER_DOUBLE);
    style2.setBorderRight(HSSFCellStyle.BORDER_DOUBLE);
    style2.setBottomBorderColor(HSSFColor.ORANGE.index);
    style2.setRightBorderColor(HSSFColor.SKY_BLUE.index);
    cell2.setCellStyle(style2);

    cell1.setCellValue("U & L");
    cell2.setCellValue("B & R");

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }
}

上面程序既改了顔色，也设置了上和左的边框各一个，右和下的边框各一个。

下面再对边框种类进行各种各样的顔色改变来看看效果。

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.util.HSSFColor;

public class POISample{
  static HSSFWorkbook workbook;

  public static void main(String[] args){
    workbook = new HSSFWorkbook();

    HSSFSheet sheet = workbook.createSheet();

    HSSFRow row[] = new HSSFRow[5];
    for (int i = 0; i < 5 ; i++){
      row[i] = sheet.createRow(i);
    }

    HSSFCell cell[][] = new HSSFCell[5][3];
    for (int i = 0; i < 5; i++){
      for (int j = 0; j < 3 ; j++){
        cell[i][j] = row[i].createCell((short)j);
      }
    }

    setStyle(cell[0][0], "DASH_DOT",
                          HSSFCellStyle.BORDER_DASH_DOT);
    setStyle(cell[0][1], "DASH_DOT_DOT",
                          HSSFCellStyle.BORDER_DASH_DOT_DOT);
    setStyle(cell[0][2], "DASHED",
                          HSSFCellStyle.BORDER_DASHED);

    setStyle(cell[1][0], "DOTTED",
                          HSSFCellStyle.BORDER_DOTTED);
    setStyle(cell[1][1], "DOUBLE",
                          HSSFCellStyle.BORDER_DOUBLE);
    setStyle(cell[1][2], "HAIR",
                          HSSFCellStyle.BORDER_HAIR);

    setStyle(cell[2][0], "MEDIUM",
                          HSSFCellStyle.BORDER_MEDIUM);
    setStyle(cell[2][1], "MEDIUM_DASH_DOT",
                          HSSFCellStyle.BORDER_MEDIUM_DASH_DOT);
    setStyle(cell[2][2], "MEDIUM_DASH_DOT_DOT",
                          HSSFCellStyle.BORDER_MEDIUM_DASH_DOT_DOT);

    setStyle(cell[3][0], "MEDIUM_DASHED",
                          HSSFCellStyle.BORDER_MEDIUM_DASHED);
    setStyle(cell[3][1], "NONE",
                          HSSFCellStyle.BORDER_NONE);
    setStyle(cell[3][2], "SLANTED_DASH_DOT",
                          HSSFCellStyle.BORDER_SLANTED_DASH_DOT);

    setStyle(cell[4][0], "THICK", HSSFCellStyle.BORDER_THICK);
    setStyle(cell[4][1], "THIN", HSSFCellStyle.BORDER_THIN);

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }

  public static void setStyle(HSSFCell cell,
                          String bn, short border){
    HSSFCellStyle style = workbook.createCellStyle();
    style.setBorderBottom(border);
    style.setBottomBorderColor(HSSFColor.ORANGE.index);
    cell.setCellStyle(style);

    cell.setCellValue(bn);
  }
}

运行结果如下：

要创建一个新的颜色，在调色板里如果有这个对应值那当然没问题。那有没有可能你想要的顔色在调色板里也没有呢？关于这个解决办法还不知道。总之，先从有对应值的来做做看吧。

首先取出现在正在使用的调色板。调色板是由「HSSFPalette」类定义的。其定义如下：

构造方法虽然有一个，但仍然是protected的，所以也不能直接使用，而要用「HSSFWorkbook」类的「getCustomPalette」方法来取得调色板对象。

getCustomPalette
public HSSFPalette getCustomPalette()

--

非常遗憾，该方法也是没有任何说明，原因不明。先按下面的方法使用吧。

HSSFWorkbook workbook = new HSSFWorkbook();
HSSFPalette palette = workbook.getCustomPalette();

调色板取得后，就可以使用「HSSFPalette」类的「setColorAtIndex」方法设定自己想要的顔色了。

setColorAtIndex
public void setColorAtIndex(short index,
              byte red, byte green, byte blue)

Sets the color at the given offset 

Parameters:
  index - the palette index, between 0x8 to
          0x40 inclusive
  red - the RGB red component, between 0
          and 255 inclusive
  green - the RGB green component, between 0
          and 255 inclusive
  blue - the RGB blue component, between 0
          and 255 inclusive

第一个参数设定你想要顔色的主色调的index号，如上一节一样，使用「HSSFColor」类的子类。

HSSFColor.RED.index

剩下的三个参数，通过设定RGB值来调节你想要的顔色。每一个都可以设定0～255的值。

HSSFWorkbook workbook = new HSSFWorkbook();

HSSFPalette palette = workbook.getCustomPalette();
palette.setColorAtIndex(HSSFColor.RED.index,
                 (byte)100, (byte)0, (byte)0);

示例程序

自己做做看吧，首先要确定你想要顔色的主色调。

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.util.HSSFColor;

public class POISample{
  public static void main(String[] args){
    HSSFWorkbook workbook = new HSSFWorkbook();

    HSSFSheet sheet = workbook.createSheet();

    HSSFRow row = sheet.createRow(1);
    HSSFCell cell = row.createCell((short)1);

    HSSFCellStyle style = workbook.createCellStyle();
    style.setFillForegroundColor(HSSFColor.RED.index);
    style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    cell.setCellStyle(style);

    cell.setCellValue("RED");

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }
}

上面程序对一个单元格设定了红色「HSSFColor.RED」的主色调，运行结果如下：

下面就对这个顔色通过RGB值来做一些改动吧。

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.hssf.usermodel.HSSFPalette;

public class POISample{
  public static void main(String[] args){
    HSSFWorkbook workbook = new HSSFWorkbook();

    HSSFPalette palette = workbook.getCustomPalette();
    palette.setColorAtIndex(HSSFColor.RED.index,
                    (byte)128, (byte)0, (byte)0);

    HSSFSheet sheet = workbook.createSheet();

    HSSFRow row = sheet.createRow(1);
    HSSFCell cell = row.createCell((short)1);

    HSSFCellStyle style = workbook.createCellStyle();
    style.setFillForegroundColor(HSSFColor.RED.index);
    style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    cell.setCellStyle(style);

    cell.setCellValue("RED");

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }
}

上面程序使用调色板对红色「HSSFColor.RED」进行了一些改动，之后用前面一个例子的方法同样设定红色，但得到的结果却是不一样的。运行结果如下：

因为调色板在一个workbook里是共有的，所以如果用调色板改变了某一种顔色，下次使用时，相同的顔色就全部改变了。

前景色的设定使用「HSSFCellStyle」类的「setFillForegroundColor」方法。

setFillForegroundColor
public void setFillForegroundColor(short bg)

set the foreground fill color 

Parameters:
  bg - color

背景色的设定则使用「HSSFCellStyle」类的「setFillBackgroundColor」方法。

setFillBackgroundColor
public void setFillBackgroundColor(short bg)

set the background fill color. 

Parameters:
  bg - color

两个方法都是通过参数来设定具体什么顔色。该参数类型为short型，在「HSSFColor」类里，准备了各种各样顔色的定义值。

HSSFColor类

HSSFColor类定义如下：

而各种顔色又是作为HSSFColor类的子类，定义一览表如下：

设定顔色时，用这些子类的静态常量「index」作为参数，使用方法如下：

HSSFWorkbook workbook = new HSSFWorkbook();

HSSFCellStyle style = workbook.createCellStyle();
style.setFillForegroundColor(HSSFColor.LIME.index);
style.setFillBackgroundColor(HSSFColor.GREEN.index);

如果这些顔色还不够你用的话，那么下一节再介绍怎么设定自己想要的顔色。

填充模式

指定填充模式的话，使用「HSSFCellStyle」类的「setFillPattern」方法。

setFillPattern
public void setFillPattern(short fp)

setting to one fills the cell with the foreground color
... No idea about other values 

Parameters:
  fp - fill pattern (set to 1 to fill w/foreground color)

指定的填充模式，在「HSSFCellStyle」类里也有定义，类型为static short型，如下所示：

实际的使用方法如下：

HSSFWorkbook workbook = new HSSFWorkbook();

HSSFCellStyle style = workbook.createCellStyle();
style.setFillForegroundColor(HSSFColor.LIME.index);
style.setFillBackgroundColor(HSSFColor.GREEN.index);

style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);

示例程序

这就实际动手做做看吧，首先看一下定义的顔色到底是什么顔色，全部拉上来看看。

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.util.HSSFColor;

public class POISample{
  static HSSFWorkbook workbook;

  public static void main(String[] args){
    workbook = new HSSFWorkbook();

    HSSFSheet sheet = workbook.createSheet();

    HSSFRow row[] = new HSSFRow[12];
    for (int i = 0; i < 12 ; i++){
      row[i] = sheet.createRow(i);
    }

    HSSFCell cell[][] = new HSSFCell[12][4];
    for (int i = 0; i < 12; i++){
      for (int j = 0; j < 4 ; j++){
        cell[i][j] = row[i].createCell((short)j);
      }
    }

    setStyle(cell[0][0], "AQUA", HSSFColor.AQUA.index);
    setStyle(cell[0][1], "BLACK", HSSFColor.BLACK.index);
    setStyle(cell[0][2], "BLUE", HSSFColor.BLUE.index);
    setStyle(cell[0][3], "BLUE_GREY", HSSFColor.BLUE_GREY.index);
    setStyle(cell[1][0], "BRIGHT_GREEN",
                              HSSFColor.BRIGHT_GREEN.index);
    setStyle(cell[1][1], "BROWN", HSSFColor.BROWN.index);
    setStyle(cell[1][2], "CORAL", HSSFColor.CORAL.index);
    setStyle(cell[1][3], "CORNFLOWER_BLUE",
                              HSSFColor.CORNFLOWER_BLUE.index);
    setStyle(cell[2][0], "DARK_BLUE", HSSFColor.DARK_BLUE.index);
    setStyle(cell[2][1], "DARK_GREEN", HSSFColor.DARK_GREEN.index);
    setStyle(cell[2][2], "DARK_RED", HSSFColor.DARK_RED.index);
    setStyle(cell[2][3], "DARK_TEAL", HSSFColor.DARK_TEAL.index);
    setStyle(cell[3][0], "DARK_YELLOW",
                              HSSFColor.DARK_YELLOW.index);
    setStyle(cell[3][1], "GOLD", HSSFColor.GOLD.index);
    setStyle(cell[3][2], "GREEN", HSSFColor.GREEN.index);
    setStyle(cell[3][3], "GREY_25_PERCENT",
                              HSSFColor.GREY_25_PERCENT.index);
    setStyle(cell[4][0], "GREY_40_PERCENT",
                              HSSFColor.GREY_40_PERCENT.index);
    setStyle(cell[4][1], "GREY_50_PERCENT",
                              HSSFColor.GREY_50_PERCENT.index);
    setStyle(cell[4][2], "GREY_80_PERCENT",
                              HSSFColor.GREY_80_PERCENT.index);
    setStyle(cell[4][3], "INDIGO", HSSFColor.INDIGO.index);
    setStyle(cell[5][0], "LAVENDER", HSSFColor.LAVENDER.index);
    setStyle(cell[5][1], "LEMON_CHIFFON",
                              HSSFColor.LEMON_CHIFFON.index);
    setStyle(cell[5][2], "LIGHT_BLUE",
                              HSSFColor.LIGHT_BLUE.index);
    setStyle(cell[5][3], "LIGHT_CORNFLOWER_BLUE",
                          HSSFColor.LIGHT_CORNFLOWER_BLUE.index);
    setStyle(cell[6][0], "LIGHT_GREEN",
                              HSSFColor.LIGHT_GREEN.index);
    setStyle(cell[6][1], "LIGHT_ORANGE",
                              HSSFColor.LIGHT_ORANGE.index);
    setStyle(cell[6][2], "LIGHT_TURQUOISE",
                              HSSFColor.LIGHT_TURQUOISE.index);
    setStyle(cell[6][3], "LIGHT_YELLOW",
                              HSSFColor.LIGHT_YELLOW.index);
    setStyle(cell[7][0], "LIME", HSSFColor.LIME.index);
    setStyle(cell[7][1], "MAROON", HSSFColor.MAROON.index);
    setStyle(cell[7][2], "OLIVE_GREEN",
                              HSSFColor.OLIVE_GREEN.index);
    setStyle(cell[7][3], "ORANGE", HSSFColor.ORANGE.index);
    setStyle(cell[8][0], "ORCHID", HSSFColor.ORCHID.index);
    setStyle(cell[8][1], "PALE_BLUE", HSSFColor.PALE_BLUE.index);
    setStyle(cell[8][2], "PINK", HSSFColor.PINK.index);
    setStyle(cell[8][3], "PLUM", HSSFColor.PLUM.index);
    setStyle(cell[9][0], "RED", HSSFColor.RED.index);
    setStyle(cell[9][1], "ROSE", HSSFColor.ROSE.index);
    setStyle(cell[9][2], "ROYAL_BLUE",
                              HSSFColor.ROYAL_BLUE.index);
    setStyle(cell[9][3], "SEA_GREEN", HSSFColor.SEA_GREEN.index);
    setStyle(cell[10][0], "SKY_BLUE", HSSFColor.SKY_BLUE.index);
    setStyle(cell[10][1], "TAN", HSSFColor.TAN.index);
    setStyle(cell[10][2], "TEAL", HSSFColor.TEAL.index);
    setStyle(cell[10][3], "TURQUOISE",
                              HSSFColor.TURQUOISE.index);
    setStyle(cell[11][0], "VIOLET", HSSFColor.VIOLET.index);
    setStyle(cell[11][1], "WHITE", HSSFColor.WHITE.index);
    setStyle(cell[11][2], "YELLOW", HSSFColor.YELLOW.index);

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }

  public static void setStyle(HSSFCell cell, String col, short fg){
    HSSFCellStyle style = workbook.createCellStyle();
    style.setFillForegroundColor(fg);
    style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    cell.setCellStyle(style);

    cell.setCellValue(col);
  }
}

上面程序只指定了「ForegroundColor」，填充模式是「SOLID_FOREGROUND」，因此顔色应该是全部充满整个单元格的。运行结果如下：

下面再对填充模式进行各种修改来看看。

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.util.HSSFColor;

public class POISample{
  static HSSFWorkbook workbook;

  public static void main(String[] args){
    workbook = new HSSFWorkbook();

    HSSFSheet sheet = workbook.createSheet();

    HSSFRow row[] = new HSSFRow[5];
    for (int i = 0; i < 5 ; i++){
      row[i] = sheet.createRow(i);
    }

    HSSFCell cell[][] = new HSSFCell[5][4];
    for (int i = 0; i < 5; i++){
      for (int j = 0; j < 4 ; j++){
        cell[i][j] = row[i].createCell((short)j);
      }
    }

    setStyle(cell[0][0], "NO_FILL", HSSFCellStyle.NO_FILL);
    setStyle(cell[0][1], "SOLID_FOREGROUND",
                              HSSFCellStyle.SOLID_FOREGROUND);
    setStyle(cell[0][2], "FINE_DOTS", HSSFCellStyle.FINE_DOTS);
    setStyle(cell[0][3], "ALT_BARS", HSSFCellStyle.ALT_BARS);

    setStyle(cell[1][0], "SPARSE_DOTS", HSSFCellStyle.SPARSE_DOTS);
    setStyle(cell[1][1], "THICK_HORZ_BANDS",
                              HSSFCellStyle.THICK_HORZ_BANDS);
    setStyle(cell[1][2], "THICK_VERT_BANDS",
                              HSSFCellStyle.THICK_VERT_BANDS);
    setStyle(cell[1][3], "THICK_BACKWARD_DIAG",
                              HSSFCellStyle.THICK_BACKWARD_DIAG);

    setStyle(cell[2][0], "THICK_FORWARD_DIAG",
                              HSSFCellStyle.THICK_FORWARD_DIAG);
    setStyle(cell[2][1], "BIG_SPOTS", HSSFCellStyle.BIG_SPOTS);
    setStyle(cell[2][2], "BRICKS", HSSFCellStyle.BRICKS);
    setStyle(cell[2][3], "THIN_HORZ_BANDS",
                              HSSFCellStyle.THIN_HORZ_BANDS);

    setStyle(cell[3][0], "THIN_VERT_BANDS",
                              HSSFCellStyle.THIN_VERT_BANDS);
    setStyle(cell[3][1], "THIN_BACKWARD_DIAG",
                              HSSFCellStyle.THIN_BACKWARD_DIAG);
    setStyle(cell[3][2], "THIN_FORWARD_DIAG",
                              HSSFCellStyle.THIN_FORWARD_DIAG);
    setStyle(cell[3][3], "SQUARES", HSSFCellStyle.SQUARES);

    setStyle(cell[4][0], "DIAMONDS", HSSFCellStyle.DIAMONDS);

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }

  public static void setStyle(HSSFCell cell, String fps,
                              short fp){
    HSSFCellStyle style = workbook.createCellStyle();
    style.setFillForegroundColor(HSSFColor.WHITE.index);
    style.setFillForegroundColor(HSSFColor.LIGHT_ORANGE.index);
    style.setFillPattern(fp);
    cell.setCellStyle(style);

    cell.setCellValue(fps);
  }
}

上面固定了「ForegroundColor」和「BackgroundColor」，而填充模式则做了各种尝试。运行结果如下：

它有一个构造方法。

虽然有构造方法，但却是protected的，所以不能直接使用，要通过一个工作簿workbook来生成格式对象。

在POI里，格式好像是以workbook为单位来管理的，所以要先作成一个格式对象，保存在workbook里，然后再对已生成好的单元格进行设定。

在单元格里指定格式

要作成一个格式对象，可以使用「HSSFWorkbook」类的「createCellStyle」方法。

createCellStyle
public HSSFCellStyle createCellStyle()

create a new Cell style and add it to the workbook's style table 

Returns:
  the new Cell Style object

另外，要取出现有的格式对象的话，使用「HSSFWorkbook」类的「getCellStyleAt」方法，这个方法有参数，是被保存格式的INDEX号。

getCellStyleAt
public HSSFCellStyle getCellStyleAt(short idx)

get the cell style object at the given index 

Parameters:
  idx - index within the set of styles
Returns:
  HSSFCellStyle object at the index

还有，对于某一个单元格，也可以取出它的格式对象。这时要使用「HSSFCell」类的「getCellStyle」方法。

getCellStyle
public HSSFCellStyle getCellStyle()

get the style for the cell. This is a reference to a cell style
contained in the workbook object.

这样的话，不管是新创建的或者是从现有的单元格里取出来的格式对象，都可以用来对某一个单元格进行格式的设定。设定方法使用「HSSFCell」类的「setCellStyle」方法。

setCellStyle
public void setCellStyle(HSSFCellStyle style)

set the style for the cell. The style should be an HSSFCellStyle
created/retreived from the HSSFWorkbook. 

Parameters:
  style - reference contained in the workbook

示例程序

关于格式的详细设定方法，下几节再讲，先做个示例程序来看看。

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.util.HSSFColor;

public class POISample{
  public static void main(String[] args){
    HSSFWorkbook workbook = new HSSFWorkbook();

    HSSFSheet sheet = workbook.createSheet();
    HSSFRow row = sheet.createRow(1);

    HSSFCell cell = row.createCell((short)0);
    cell.setCellValue("sample");

    HSSFCellStyle style = workbook.createCellStyle();
    style.setFillBackgroundColor(HSSFColor.WHITE.index);
    style.setFillForegroundColor(HSSFColor.LIGHT_ORANGE.index);
    style.setFillPattern(HSSFCellStyle.THICK_HORZ_BANDS);

    cell.setCellStyle(style);

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }
}

按上面程序，在某一个单元格里设定了顔色。运行结果如下：

好了，从下一节开始详细介绍单元格格式的设定。

两个方法，在DOC文档里都没有详细说明，原因不明。总之，先动手做做看。首先来看看如何从单元格取出函数式。

上图中，在单元格「C:2」里的函数式是「=A2*B2」，「C:3」里的函数式是「=SUM(A3:B3)」。

import java.io.*;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;

public class POISample{
  public static void main(String[] args){
    FileInputStream in = null;
    HSSFWorkbook workbook = null;

    try{
      in = new FileInputStream("sample.xls");
      POIFSFileSystem fs = new POIFSFileSystem(in);
      workbook = new HSSFWorkbook(fs);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try{
        in.close();
      }catch (IOException e){
        System.out.println(e.toString());
      }
    }

    HSSFSheet sheet = workbook.getSheetAt(0);

    HSSFRow row1 = sheet.getRow(1);

    HSSFCell cell1 = row1.getCell((short)2);
    System.out.println("C:2的函数式 " + cell1.getCellFormula());

    HSSFRow row2 = sheet.getRow(2);

    HSSFCell cell2 = row2.getCell((short)2);
    System.out.println("C:3的函数式 " + cell2.getCellFormula());
  }
}

实行结果如下：

C:2的函数式 A2*B2
C:3的函数式 SUM(A3:B3)

如上所示，函数式被正常取出，只是函数式前的「=」被省略了。

下面再来看看如何向单元格写入函数式。还是利用之前的Excel文件，「C:2」单元格里写入「A2+B2」，「C:3」单元格里写入「AVERAGE(A3,B3)」这样的函数式。

import java.io.*;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;

public class POISample{
  public static void main(String[] args){
    FileInputStream in = null;
    HSSFWorkbook workbook = null;

    try{
      in = new FileInputStream("sample.xls");
      POIFSFileSystem fs = new POIFSFileSystem(in);
      workbook = new HSSFWorkbook(fs);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try{
        in.close();
      }catch (IOException e){
        System.out.println(e.toString());
      }
    }

    HSSFSheet sheet = workbook.getSheetAt(0);

    HSSFRow row1 = sheet.getRow(1);
    HSSFCell cell1 = row1.createCell((short)2);
    cell1.setCellFormula("A2+B2");

    HSSFRow row2 = sheet.getRow(2);
    HSSFCell cell2 = row2.createCell((short)2);
    cell2.setCellFormula("AVERAGE(A3,B3)");

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample3.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }
}

实行结果如下：

到底什么样的函数式可以用，什么样的不能用，这一点还不是很明白，但至少一部分是可以用的。

最后要注意的就是，对于使用getCell方法获取的单元格，函数式是不能被写入的。因此对于已经存在的单元格，在写入函数式时，只能先通过createCell方法创建单元格，再写入函数式。

要获取单元格值的类型，使用「HSSFCell」类的「getCellType」方法。

getCellType
public int getCellType()

get the cells type (numeric, formula or string)

下面就是类型和定义值的一览表。

示例程序

下面来实际动手做做看。按下图准备一个Excel文件。

import java.io.*;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;

public class POISample{
  public static void main(String[] args){
    FileInputStream in = null;
    HSSFWorkbook workbook = null;

    try{
      in = new FileInputStream("sample.xls");
      POIFSFileSystem fs = new POIFSFileSystem(in);
      workbook = new HSSFWorkbook(fs);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try{
        in.close();
      }catch (IOException e){
        System.out.println(e.toString());
      }
    }

    HSSFSheet sheet = workbook.getSheetAt(0);
    HSSFRow row = sheet.getRow(1);

    HSSFCell cell = row.getCell((short)0);
    System.out.println("A:2=" + getType(cell.getCellType()));

    cell = row.getCell((short)1);
    System.out.println("B:2=" + getType(cell.getCellType()));

    cell = row.getCell((short)2);
    System.out.println("C:2=" + getType(cell.getCellType()));

    cell = row.getCell((short)3);
    System.out.println("D:2=" + getType(cell.getCellType()));

    cell = row.getCell((short)4);
    System.out.println("E:2=" + getType(cell.getCellType()));
  }

  public static String getType(int type){
    if (type == HSSFCell.CELL_TYPE_BLANK){
      return "CELL_TYPE_BLANK";
    }else if (type == HSSFCell.CELL_TYPE_BOOLEAN){
      return "CELL_TYPE_BOOLEAN";
    }else if (type == HSSFCell.CELL_TYPE_ERROR){
      return "CELL_TYPE_ERROR";
    }else if (type == HSSFCell.CELL_TYPE_FORMULA){
      return "CELL_TYPE_FORMULA";
    }else if (type == HSSFCell.CELL_TYPE_NUMERIC){
      return "CELL_TYPE_NUMERIC";
    }else if (type == HSSFCell.CELL_TYPE_STRING){
      return "CELL_TYPE_STRING";
    }else{
      return "Not defined";
    }
  }
}

实行结果如下：

A:2=CELL_TYPE_NUMERIC
B:2=CELL_TYPE_STRING
C:2=CELL_TYPE_BOOLEAN
D:2=CELL_TYPE_NUMERIC
E:2=CELL_TYPE_ERROR

有一点要注意的是，数值型和日期型都是「CELL_TYPE_NUMERIC」。

日期型检查

到底是数值型还是日期型，可以通过「org.apache.poi.hssf.usermodel.HSSFDateUtil」类的「isCellDateFormatted」方法来检证。

isCellDateFormatted
public static boolean isCellDateFormatted(HSSFCell cell)

Check if a cell contains a date Since dates are
stored internally in Excel as double values we
infer it is a date if it is formatted as such.

因为这个方法是静态的，可以直接调用如下所示。

if (HSSFDateUtil.isCellDateFormatted(cell)){
    /* 日期型 */
}

现在就把之前的示例程序稍微改动一下，再运行看看。

import java.io.*;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;

public class POISample{
  public static void main(String[] args){
    FileInputStream in = null;
    HSSFWorkbook workbook = null;

    try{
      in = new FileInputStream("sample.xls");
      POIFSFileSystem fs = new POIFSFileSystem(in);
      workbook = new HSSFWorkbook(fs);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try{
        in.close();
      }catch (IOException e){
        System.out.println(e.toString());
      }
    }

    HSSFSheet sheet = workbook.getSheetAt(0);
    HSSFRow row = sheet.getRow(1);

    HSSFCell cell = row.getCell((short)0);
    System.out.println("A:2=" + getType(cell));

    cell = row.getCell((short)1);
    System.out.println("B:2=" + getType(cell));

    cell = row.getCell((short)2);
    System.out.println("C:2=" + getType(cell));

    cell = row.getCell((short)3);
    System.out.println("D:2=" + getType(cell));

    cell = row.getCell((short)4);
    System.out.println("E:2=" + getType(cell));
  }

  public static String getType(HSSFCell cell){
    int type = cell.getCellType();

    if (type == HSSFCell.CELL_TYPE_BLANK){
      return "CELL_TYPE_BLANK";
    }else if (type == HSSFCell.CELL_TYPE_BOOLEAN){
      return "CELL_TYPE_BOOLEAN";
    }else if (type == HSSFCell.CELL_TYPE_ERROR){
      return "CELL_TYPE_ERROR";
    }else if (type == HSSFCell.CELL_TYPE_FORMULA){
      return "CELL_TYPE_FORMULA";
    }else if (type == HSSFCell.CELL_TYPE_NUMERIC){
      if (HSSFDateUtil.isCellDateFormatted(cell)){
        return "CELL_TYPE_DATE";
      }else{
        return "CELL_TYPE_NUMERIC";
      }
    }else if (type == HSSFCell.CELL_TYPE_STRING){
      return "CELL_TYPE_STRING";
    }else{
      return "Not defined";
    }
  }
}

实行结果如下：

A:2=CELL_TYPE_NUMERIC
B:2=CELL_TYPE_STRING
C:2=CELL_TYPE_BOOLEAN
D:2=CELL_TYPE_DATE
E:2=CELL_TYPE_ERROR

这一次，日期型也可以被检查出来了。

setEncoding
public void setEncoding(short encoding)

set the encoding to either 8 or 16 bit. (US/UK use 8-bit,
rest of the western world use 16bit) 

Parameters:
  encoding - either ENCODING_COMPRESSED_UNICODE (0)
    or ENCODING_UTF_16 (1)

示例程序

用下面程序来做做看。

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;

public class POISample{
  public static void main(String[] args){
    HSSFWorkbook workbook = new HSSFWorkbook();

    HSSFSheet sheet = workbook.createSheet();

    HSSFRow row1 = sheet.createRow(1);

    HSSFCell cell1 = row1.createCell((short)0);
    //cell1.setEncoding(HSSFCell.ENCODING_UTF_16);
    cell1.setCellValue("使用中文");

    HSSFCell cell2 = row1.createCell((short)1);
    //cell2.setEncoding(HSSFCell.ENCODING_COMPRESSED_UNICODE);
    cell2.setCellValue("日本語を使う");

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }
}

运行结果如下：