Java使用itext组件导出pdf报表，导出pdf文件一般是系统中常支持的功能，输出pdf之后可以打印，下面介绍导出pdf一般使用的功能，介绍怎么 在pdf插入浮动层图片(类似HTML中div)，有(X、Y)坐标确定图片的位置。
iText使用的版本是：itextpdf-5.5.1.jar, 可以去iText官网下载

iText输出pdf最基本是输出table表格，下面是输出区域、总销售额(万元)、总利润(万元)简单的表格,创建Document文档对象，其可以加入表格table，pdf文档大小设置为A4，通过PdfWriter对象将pdf文件写入到输出流中。
getPdfChineseFont()方法解决中文乱码，需要加入itext-asian.jar

          

float[] widths = {144, 113, 191};
FileOutputStream fos = new FileOutputStream("/Users/mike/table1.pdf");

Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, fos);
writer.setViewerPreferences(PdfWriter.PageModeUseThumbs);
document.setPageSize(PageSize.A4);//设置A4
document.open();

PdfPTable table = new PdfPTable(widths);
table.setTotalWidth(458);
table.setHorizontalAlignment(Element.ALIGN_LEFT);

Object[][] datas = {{"区域", "总销售额(万元)", "总利润(万元)简单的表格"}, {"江苏省" , 9045,  2256}, {"广东省", 3000, 690}};
for(int i = 0; i < datas.length; i++) {
    for(int j = 0; j < datas[i].length; j++) {
        PdfPCell pdfCell = new PdfPCell(); //表格的单元格
        Paragraph paragraph = new Paragraph(StringUtil.getString(datas[i][j]), getPdfChineseFont());
        pdfCell.setPhrase(paragraph);
        table.addCell(pdfCell);
    }
}

document.add(table); //pdf文档中加入table
document.close();

public static Font getPdfChineseFont() throws Exception {
    BaseFont bfChinese = BaseFont.createFont("STSongStd-Light", "UniGB-UCS2-H",
            BaseFont.NOT_EMBEDDED);
    Font fontChinese = new Font(bfChinese, 12, Font.NORMAL);
    return fontChinese;
}
              

有时单元格文本比较多，需要设置表格的列宽度，在初始化PdfTable可以指定每列的宽度，使用单元格对象PdfCell设置表格行高度,
table的setLockedWidth(true)方法设置表格为固定宽度，这时必须设置setTotalWidth(458)表格宽度

          

FileOutputStream fos = new FileOutputStream("/Users/mike/table2.pdf");
Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, fos);
writer.setViewerPreferences(PdfWriter.PageModeUseThumbs);
document.setPageSize(PageSize.A4);
document.open();

float[] widths = {144, 113, 191}; //设置三列表格的宽度
PdfPTable table = new PdfPTable(widths);
table.setLockedWidth(true);
table.setTotalWidth(458);
table.setHorizontalAlignment(Element.ALIGN_LEFT);

Object[][] datas = {{"区域", "总销售额(万元)", "总利润(万元)简单的表格"}, {"江苏省" , 9045,  2256}, {"广东省", 3000, 690}};
for(int i = 0; i < datas.length; i++) {
    for(int j = 0; j < datas[i].length; j++) {
        PdfPCell pdfCell = new PdfPCell();
        pdfCell.setMinimumHeight(30);//设置表格行高
        Paragraph paragraph = new Paragraph(StringUtil.getString(datas[i][j]), getPdfChineseFont());
        pdfCell.setPhrase(paragraph);
        table.addCell(pdfCell);
    }
}

document.add(table);
document.close();
                

单元格可以设置居左、居中、居右、上下居中、设置边框、设置边框颜色、设置单元格背景颜色等, 使用PdfCell对象设置，颜色比比较简单直接时16进制rgb值。

          

pdfCell.setHorizontalAlignment(Element.ALIGN_CENTER);
pdfCell.setVerticalAlignment(Element.ALIGN_MIDDLE);
pdfCell.setBackgroundColor(new BaseColor(0xdd7e6b));

pdfCell.setBorderWidthTop(0.1f);
pdfCell.setBorderWidthBottom(0.1f);
pdfCell.setBorderWidthLeft(0.1f);
pdfCell.setBorderWidthRight(0.1f);
pdfCell.setBorderColorBottom(new BaseColor(0x674ea7));
pdfCell.setBorderColorLeft(new BaseColor(0x674ea7));
pdfCell.setBorderColorRight(new BaseColor(0x674ea7));
pdfCell.setBorderColorTop(new BaseColor(0x674ea7));
                

单元格文本可设置字体大小、颜色、斜体、粗体、下划线等,对于设置字体粗体、斜体、下划线则都使用font.setStyle()方法，
这个font是com.itextpdf.text.Font不是Java的Font, setStyle方法内部会做或操作。

          

Font font = getPdfChineseFont();

font.setColor(new BaseColor(0xff0000));
font.setSize(16);
font.setStyle("bold");
font.setStyle("italic");
font.setStyle("underline");

public static Font getPdfChineseFont() throws Exception {
    BaseFont bfChinese = BaseFont.createFont("STSongStd-Light", "UniGB-UCS2-H",
            BaseFont.NOT_EMBEDDED);
    Font fontChinese = new Font(bfChinese, 12, Font.NORMAL);
    return fontChinese;
}
                

PdfCell做单元格合并比较简单，直接调用setRowspan与setColspan方法，
如下第一行3列合并, 被合并的单元格不需要加入table中(table.addCell(pdfCell))，否则会出现表格错乱的情况。

          

pdfCell.setRowspan(1);
pdfCell.setColspan(3);
                

单元格中不仅是文本、数值、也可以加入图片，直接调用pdfCell.setImage()方法。

          

//单元格插入图片
byte[] bt = FileUtils.readFileToByteArray(new File("/Users/mike/pie.png"));
PdfPCell pdfCell = new PdfPCell();
pdfCell.setImage(Image.getInstance(bt));//插入图片
table.addCell(pdfCell);
table.addCell(new PdfPCell());
table.addCell(new PdfPCell());

ClientAnchor anchor = helper.createClientAnchor();
anchor.setCol1(0); //图片开始列数
anchor.setRow1(4); //图片开始行数
anchor.setCol2(3); //图片结束列数
anchor.setRow2(25);//图片结束行数
drawing.createPicture(anchor, pictureIdx);
                

pdf中插入图片, iText导出pdf可以根据绝对位置X、Y坐标值插入图片，然后将image加入到pdf文档document中，上面的例子是document中加入表格table, pdf文档开始坐标位置在左下角位置，所以使用document的高度(PageSize.A4.getHeight())减去y值和图片自身高度.

          

//文档插入绝对位置图片
Image image = Image.getInstance(bt);
int x = 30; 
int y = 230;
image.setAbsolutePosition(x + document.leftMargin(),  PageSize.A4.getHeight() - y -
        image.getHeight() - document.topMargin());
document.add(image);
                

pdf表格中可以加入子表格，通过pdfCell.addElement(suTtable)方法加入（sub1、sub2）子表格

          

//插入子表格
pdfCell = new PdfPCell(); 
pdfCell.setRowspan(1);
pdfCell.setColspan(2);

PdfPTable suTtable = new PdfPTable(new float[]{100,100});
PdfPCell subPdfCell = new PdfPCell(); 
subPdfCell.setPhrase(new Paragraph("sub1", getPdfChineseFont()));
suTtable.addCell(subPdfCell);
subPdfCell = new PdfPCell();  
subPdfCell.setPhrase(new Paragraph("sub2", getPdfChineseFont()));
suTtable.addCell(subPdfCell);

pdfCell.addElement(suTtable);//添加子表格
table.addCell(pdfCell);

                

iText pdf单元格中画斜线另一篇有详细介绍：iText报表表格画斜线

iText导出pdf例子源码

import java.io.File;
import java.io.FileOutputStream;

import org.apache.commons.io.FileUtils;

import com.itextpdf.text.BaseColor;
import com.itextpdf.text.Document;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfPCell;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfWriter;

import cn.cztc.jreport.util.StringUtil;

public class TestExportPdf {

    public static void main(String[] args) throws Exception {
       
        FileOutputStream fos = new FileOutputStream("/Users/mike/table8.pdf");
        Document document = new Document();
        PdfWriter writer = PdfWriter.getInstance(document, fos);
        writer.setViewerPreferences(PdfWriter.PageModeUseThumbs);
        document.setPageSize(PageSize.A4);
        document.open();
        
        float[] widths = {144, 113, 191};
        PdfPTable table = new PdfPTable(widths);
        table.setLockedWidth(true);
        table.setTotalWidth(458);
        table.setHorizontalAlignment(Element.ALIGN_LEFT);
        
        Object[][] datas = {{"区域产品销售额"},{"区域", "总销售额(万元)", "总利润(万元)简单的表格"}, {"江苏省" , 9045,  2256}, {"广东省", 3000, 690}};
        for(int i = 0; i < datas.length; i++) {
            for(int j = 0; j < datas[i].length; j++) {
                PdfPCell pdfCell = new PdfPCell();
                pdfCell.setMinimumHeight(30);
                
                //设置单元格样式
                pdfCell.setHorizontalAlignment(Element.ALIGN_CENTER);
                pdfCell.setVerticalAlignment(Element.ALIGN_MIDDLE);
                pdfCell.setBackgroundColor(new BaseColor(0xdd7e6b));
                
                pdfCell.setBorder(0);
                pdfCell.setBorderWidthTop(0.1f);
                pdfCell.setBorderWidthBottom(0.1f);
                pdfCell.setBorderWidthLeft(0.1f);
                pdfCell.setBorderWidthRight(0.1f);
                pdfCell.setBorderColorBottom(new BaseColor(0x674ea7));
                pdfCell.setBorderColorLeft(new BaseColor(0x674ea7));
                pdfCell.setBorderColorRight(new BaseColor(0x674ea7));
                pdfCell.setBorderColorTop(new BaseColor(0x674ea7));
                
                //设置单元格文本字体样式
                Font font = getPdfChineseFont();
                if(i == datas.length - 1 && j == 3 - 1) {
                    font.setColor(new BaseColor(0xff0000));
                    font.setSize(16);
                    font.setStyle("bold");
                    font.setStyle("italic");
                    font.setStyle("underline");
                }
                
                //合并单元格
                if(i == 0 && j == 0) {
                    pdfCell.setRowspan(1);
                    pdfCell.setColspan(3);
                }
                
                Paragraph paragraph = new Paragraph(StringUtil.getString(datas[i][j]), font);
                pdfCell.setPhrase(paragraph);
                                
                table.addCell(pdfCell);
            }
        }
        
        //单元格插入图片
        byte[] bt = FileUtils.readFileToByteArray(new File("/Users/mike/pie.png"));
        PdfPCell pdfCell = new PdfPCell();
        pdfCell.setImage(Image.getInstance(bt));
        table.addCell(pdfCell);
        
        //插入子表格
        pdfCell = new PdfPCell(); 
        pdfCell.setRowspan(1);
        pdfCell.setColspan(2);
        
        PdfPTable suTtable = new PdfPTable(new float[]{100, 100});
        PdfPCell subPdfCell = new PdfPCell(); 
        subPdfCell.setPhrase(new Paragraph("sub1", getPdfChineseFont()));
        suTtable.addCell(subPdfCell);
        subPdfCell = new PdfPCell();  
        subPdfCell.setPhrase(new Paragraph("sub2", getPdfChineseFont()));
        suTtable.addCell(subPdfCell);
        
        pdfCell.addElement(suTtable);
        table.addCell(pdfCell);
   
        document.add(table);
        
        //文档插入绝对位置图片
        Image image = Image.getInstance(bt);
        int x = 30; 
        int y = 230;
        image.setAbsolutePosition(x + document.leftMargin(),  PageSize.A4.getHeight() - y -
                image.getHeight() - document.topMargin());
        document.add(image);
        
        document.close();
    }

    public static Font getPdfChineseFont() throws Exception {
        BaseFont bfChinese = BaseFont.createFont("STSongStd-Light", "UniGB-UCS2-H",
                BaseFont.NOT_EMBEDDED);
        Font fontChinese = new Font(bfChinese, 12, Font.NORMAL);
        return fontChinese;
    }
}