Freemarker+Flying sauser +Itext 整合生成PDF
Freemarker、Flying sauser 、Itext ，这三个框架的作用就不详细介绍了，google一下就知道了。
Itext提供了很多底层的API，让我们可以用java代码画一个pdf出来，但是很不灵活，布局渲染代码都hard code 进java类里面了。
当需求发生改变时，哪怕只需要更改一个属性名，我们都要重新修改那段代码，很不符合开放关闭的原则。想到用模版来做渲染，但自己实现起来比较繁琐，然后google了下，找到了用freemarker做模版，Flying sauser 照着模版做渲染，让Itext做输出生成PDF的方案。
freemarker和itext都比较熟悉了，Flying sauser 第一次听说，看完官方的user guide(http://flyingsaucerproject.github.com/flyingsaucer/r8/guide/users-guide-R8.html)后，自己着手做了个demo实践：
测试数据模型:
package com.jeemiss.pdfsimple.entity;
public class User {
private String name;
private int age;
private int sex;
/**
* Constructor with all fields
*
* @param name
* @param age
* @param sex
*/
public User(String name, int age, int sex) {
super();
this.name = name;
this.age = age;
this.sex = sex;
}
/////////////////////// getter and setter ///////////////////////////////////////////
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public int getSex() {
return sex;
}
public void setSex(int sex) {
this.sex = sex;
}
}
package com.jeemiss.pdfsimple.freemarker;
import freemarker.template.Configuration;
public class FreemarkerConfiguration {
private static Configuration config = null;
/**
* Static initialization.
*
* Initialize the configuration of Freemarker.
*/
static{
config = new Configuration();
config.setClassForTemplateLoading(FreemarkerConfiguration.class, "template");
}
public static Configuration getConfiguation(){
return config;
}
}
HTML生成器:
package com.jeemiss.pdfsimple.generator;
import java.io.BufferedWriter;
import java.io.StringWriter;
import java.util.Map;
import com.jeemiss.pdfsimple.freemarker.FreemarkerConfiguration;
import freemarker.template.Configuration;
import freemarker.template.Template;
public class HtmlGenerator {
/**
* Generate html string.
*
* @param template the name of freemarker teamlate.
* @param variables the data of teamlate.
* @return htmlStr
* @throws Exception
*/
public static String generate(String template, Map<String,Object> variables) throws Exception{
Configuration config = FreemarkerConfiguration.getConfiguation();
Template tp = config.getTemplate(template);
StringWriter stringWriter = new StringWriter();
BufferedWriter writer = new BufferedWriter(stringWriter);
tp.setEncoding("UTF-8");
tp.process(variables, writer);
String htmlStr = stringWriter.toString();
writer.flush();
writer.close();
return htmlStr;
}
}
PDF 生成器：
package com.jeemiss.pdfsimple.generator;
import java.io.ByteArrayInputStream;
import java.io.OutputStream;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.xhtmlrenderer.pdf.ITextRenderer;
public class PdfGenerator {
/**
* Output a pdf to the specified outputstream
*
* @param htmlStr the htmlstr
* @param out the specified outputstream
* @throws Exception
*/
public static void generate(String htmlStr, OutputStream out)
throws Exception {
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = builder.parse(new ByteArrayInputStream(htmlStr.getBytes()));
ITextRenderer renderer = new ITextRenderer();
renderer.setDocument(doc, null);
renderer.layout();
renderer.createPDF(out);
out.close();
}
}
用来做测试的ftl模版，用到部分css3.0的属性来控制pdf强制分页和输出分页信息
<html>
<head>
<title>${title}</title>
<style>
table {
width:100%;border:green dotted ;border-width:2 0 0 2
}
td {
border:green dotted;border-width:0 2 2 0
}
@page {
size: 8.5in 11in;
@bottom-center {
content: "page " counter(page) " of " counter(pages);
}
}
</style>
</head>
<body>
<h1>Just a blank page.</h1>
<div style="page-break-before:always;">
<div align="center">
<h1>${title}</h1>
</div>
<table>
<tr>
<td><b>Name</b></td>
<td><b>Age</b></td>
<td><b>Sex</b></td>
</tr>
<#list userList as user>
<tr>
<td>${user.name}</td>
<td>${user.age}</td>
<td>
<#if user.sex = 1>
male
<#else>
female
</#if>
</td>
</tr>
</#list>
</table>
</div>
</body>
</html>
最后写个测试用例看看:
package com.jeemiss.pdfsimple.test;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.junit.Test;
import com.jeemiss.pdfsimple.entity.User;
import com.jeemiss.pdfsimple.generator.HtmlGenerator;
import com.jeemiss.pdfsimple.generator.PdfGenerator;
public class TestCase
{
@Test
public void generatePDF() {
try{
String outputFile = "C:\\sample.pdf";
Map<String,Object> variables = new HashMap<String,Object>();
List<User> userList = new ArrayList<User>();
User tom = new User("Tom",19,1);
User amy = new User("Amy",28,0);
User leo = new User("Leo",23,1);
userList.add(tom);
userList.add(amy);
userList.add(leo);
variables.put("title", "User List");
variables.put("userList", userList);
String htmlStr = HtmlGenerator.generate("sample.ftl", variables);
OutputStream out = new FileOutputStream(outputFile);
PdfGenerator.generate(htmlStr, out);
}catch(Exception ex){
ex.printStackTrace();
}
}
}
到C盘下打开sample.pdf ，看看输出的结果:
