freemarker简单使用
- 依赖
<!-- feermarker -->
<dependency>
<groupId>org.freemarker</groupId>
<artifactId>freemarker</artifactId>
<version>2.3.28</version>
</dependency>
- 创建对象
@Data
@ToString
public class Student {
private String name;//姓名
private int age;//年龄
@JsonProperty("dd.MM.yyyy HH:mm:ss")
private Date birthday;//生日
private Float money;//钱包
private List<Student> friends;//朋友列表
private Student bestFriend;//最好的朋友
}
- 创建模板【ftl1.ftl】
<!DOCTYPE html>
<html>
<head>
<meta charset="utf‐8">
<title>Hello World!</title>
</head>
<body>
<h1>Hello ${name}!</h1>
<h2>1-对象</h2>
<#--
// 1-放置对象
Student stu1 = new Student();
stu1.setName("xiaoai");
stu1.setAge(21);
stu1.setMoney(1000.86f);
stu1.setBirthday(new Date());
map.put("stu1",stu1);//向数据模型放数据
-->
-----stu1-----<br/>
name：${stu1.name}<br/>
age:${stu1.age}<br/>
money:${stu1.money}<br/>
birthday:${stu1.birthday?string("yyyy年MM月dd日 HH:mm:ss")}<br/>
<h2>2-列表遍历 + if判断</h2>
<#--
-->
<table border="1px solid">
<tr>
<td>姓名</td>
<td>年龄</td>
<td>出生日期</td>
<td>钱包</td>
<td>最好的朋友</td>
<td>朋友个数</td>
<td>朋友列表</td>
</tr>
<#if stuList??> <#--如果stuList存在-->
<#list stuList as stu>
<tr>
<td
<#if stu.name =='xiaoai'>
style="background:red;"
</#if>
>
${stu.name!''}
</td>
<td>${stu.age}</td>
<td>${(stu.birthday?date)!''}</td>
<td>${stu.money}</td>
<td>${(stu.bestFriend.name)!''}</td>
<td>${(stu.friends?size)!0}</td>
<td>
<#if stu.friends??>
<#list stu.friends as firend>
${firend.name!''}<br/>
</#list>
</#if>
</td>
</tr>
</#list>
</#if>
</table>
<h2>3-list</h2>
<#--
-->
<table border="1px solid">
<tr>
<td>序号</td>
<td>姓名</td>
<td>年龄</td>
<td>钱包</td>
</tr>
<#list stuList as stu>
<tr>
<td>${stu_index + 1}</td>
<td>${stu.name}</td>
<td>${stu.age}</td>
<td>${stu.money}</td>
</tr>
</#list>
</table>
<h2>4-map</h2>
<#--
-->
输出学生信息：<br/>
-----stu1-----<br/>
name：${stuMap['stu1'].name}<br/>
age:${stuMap['stu1'].age}<br/>
-----stu2-----<br/>
name:${stuMap.stu2.name}<br/>
age:${stuMap.stu2.age}<br/>
遍历学生：<br/>
<table border="1px solid">
<tr>
<td>序号</td>
<td>姓名</td>
<td>年龄</td>
<td>钱包</td>
</tr>
<#list stuMap?keys as key>
<tr>
<td>${key_index +1 }</td>
<td>${stuMap[key].name}</td>
<td>${stuMap[key].age}</td>
<td>${stuMap[key].money}</td>
</tr>
</#list>
</table>
<h2>指令1：if</h2>
<#--
-->
<h2>内建函数：</h2>
1-集合大小：${stuList?size}<br>
<#-- 2-函数引用：${stu1?toString}-->
<p>end...</p>
</body>
</html>
- 添加接口
@RequestMapping("/freemarker")
@Controller
public class FreemarkerController {
// @Autowired
// RestTemplate restTemplate;
@RequestMapping("/ftl1")
public String freemarker(Map<String, Object> map){
map.put("name","xiaoai");
// 1-放置对象
Student stu1 = new Student();
stu1.setName("xiaoai");
stu1.setAge(21);
stu1.setMoney(1000.86f);
stu1.setBirthday(new Date());
map.put("stu1",stu1);//向数据模型放数据
// 2-列表
Student stu2 = new Student();
stu2.setName("xiaoai2");
stu2.setAge(25);
stu2.setMoney(4000.86f);
stu2.setBirthday(new Date());
// 朋友列表
Student stu3 = new Student();
stu3.setName("xiaoai3");
stu3.setAge(23);
stu3.setMoney(43300.86f);
stu3.setBirthday(new Date());
List<Student> friends = new ArrayList<>();
friends.add(stu1);
friends.add(stu3);
stu2.setFriends(friends);
stu2.setBestFriend(stu1);
// 3-list
List<Student> stuList = new ArrayList<>();
stuList.add(stu1);
stuList.add(stu2);
map.put("stuList",stuList); //向数据模型放数据
//map
HashMap<String,Student> stuMap = new HashMap<>();
stuMap.put("stu1",stu1);
stuMap.put("stu2",stu2);
map.put("stuMap",stuMap);//向数据模型放数据
//返回模板文件名称
return "ftl1";
}
}
静态化
一、简单模板静态化
- 创建模板【test.ftl】
{
"cityId": ${cityId},
"cityName": ${cityName},
"cky2": ${cky2},
"countryId": ${contryId}
}
- 创建工具类
public class FreeMarkerUtils {
public static String getDate(String filepath, Map<Object,Object> mode)
throws IOException, TemplateException {
StringWriter writer = new StringWriter();
// 创建配置类
Configuration cfg = new Configuration(Configuration.getVersion());
// 设置模板加载机制：
// 1、类加载机制加载模板
cfg.setClassForTemplateLoading(FreeMarkerUtils.class,"/freemarker");
// 2-1、目录路径加载模板
// cfg.setDirectoryForTemplateLoading(new File("/freemarker"));
// 2-2、目录路径加载模板
// String classpath = FreeMarkerUtils.class.getResource("/").getPath();
// cfg.setDirectoryForTemplateLoading(new File(classpath +"/freemarker"));
// 设置字符集
cfg.setDefaultEncoding("UTF-8");
// 加载模板
Template template = cfg.getTemplate(filepath);
// 静态化内容：
// 1.
template.process(mode,writer);
// 2.
return writer.toString();
}
}
- 测试
@Test
public void testFreeMarkerToJson(){
String filePath = "testFm.ftl";
Map<Object, Object> mode = new HashMap<>();
mode.put("cityId","1001");
mode.put("cityName","深圳");
mode.put("cky2","800");
mode.put("contryId","000001");
try {
String date = FreeMarkerUtils.getDate(filePath, mode);
System.out.println(date);
} catch (IOException e) {
e.printStackTrace();
} catch (TemplateException e) {
e.printStackTrace();
}
}
二、一次性收集模板(xml)
- 创建xml解析类
@XmlRootElement(name = "mappingItem")
public class MappingItem {
private String solutionName;
private String templateName;
@XmlAttribute(name = "solutionName")
public String getSolutionName() {
return solutionName;
}
public void setSolutionName(String solutionName) {
this.solutionName = solutionName;
}
@XmlAttribute(name = "templationName")
public String getTemplateName() {
return templateName;
}
public void setTemplateName(String templateName) {
this.templateName = templateName;
}
}
//----------
@XmlRootElement(name = "templateMapping")
public class TemplateMapping {
private List<MappingItem> mappingItemList;
@XmlElement(name = "mappingItem")
public List<MappingItem> getMappingItemList() {
return mappingItemList;
}
public void setMappingItemList(List<MappingItem> mappingItemList) {
this.mappingItemList = mappingItemList;
}
}
- 创建工具类
public class FreeMarkerUtils {
private static final Logger LOGGER = LoggerFactory.getLogger(FreeMarkerUtils.class);
private static Configuration cfg = new Configuration(Configuration.VERSION_2_3_28);
static {
try {
cfg.setDefaultEncoding("UTF-8");
cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
cfg.setClassForTemplateLoading(FreeMarkerUtils.class,"/freemarker_template");
} catch (Exception ex){
LOGGER.error("FreeMaerkerUtils error." + ex.getMessage(), ex);
}
}
public FreeMarkerUtils() { }
public static String processData(Map<String,Object> model, String templateName){
String result = "";
try (StringWriter out = new StringWriter()){
Locale locale = LocaleContextHolder.getLocale();
Template template = cfg.getTemplate(templateName, locale);
template.process(model, out);
result = out.toString();
} catch (IOException | TemplateException e) {
e.printStackTrace();
}
return result;
}
// 1、通过xml配置文件获取模板
public static Map<String, String> getTemplateConfig(){
Map<String, String> templateConfig = new HashMap<>();
try (InputStream inputStream = FreeMarkerUtils.class.getResourceAsStream(
"/freemarker_template/freemarker_template_mapping.xml")){
// 读取jar包内置文件
JAXBContext context = JAXBContext.newInstance(TemplateMapping.class);
Unmarshaller unmarshaller = context.createUnmarshaller();
XMLInputFactory xif = XMLInputFactory.newFactory();
xif.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES,false);
xif.setProperty(XMLInputFactory.SUPPORT_DTD, false);
XMLStreamReader xsr = xif.createXMLStreamReader(inputStream);
TemplateMapping templateMapping = (TemplateMapping) unmarshaller.unmarshal(xsr);
List<MappingItem> mappingItemList = templateMapping.getMappingItemList();
for (MappingItem mappingItem : mappingItemList) {
templateConfig.put(mappingItem.getSolutionName(), mappingItem.getTemplateName());
}
} catch (Exception ex){
LOGGER.error(ex.getMessage());
}
return templateConfig;
}
// 2、通过路径获取模板
private Map<String, String> templateFiles = new HashMap<>();
@Value("${template.base-template-path:/freemarker_template}")
public String baceTemplatePath;
@Value("${template.base-template-path:.ftl}")
public String templateSuffix;
@PostConstruct
protected void initTemplateFile(){
try {
URL resource = FreeMarkerUtils.class.getResource(baceTemplatePath);
String rootPath = resource.getPath();
File rootFile = new File(rootPath);
File[] listFiles = rootFile.listFiles();
Objects.requireNonNull(listFiles, String.format(Locale.ROOT, "[%s] no template file.", baceTemplatePath));
for (File file : listFiles) {
if (!Objects.isNull(file) && file.isFile() && file.getName().endsWith(templateSuffix)){
String filePath = file.getPath();
String fileName = file.getName();
templateFiles.put(
fileName.substring(0,fileName.lastIndexOf(".")), filePath.substring(rootPath.length())
);
LOGGER.info("get template path:" + filePath);
}
}
} catch (Exception exception){
LOGGER.error("initTemplateFile faild.", exception.getMessage());
}
}
public Map<String, String> getTemplateFiles() {
return templateFiles;
}
- 创建目录及定义模板
// 【/freemarker_template/freemarker_template_mapping.xml】
<?xml version="1.0" encoding="utf-8" ?>
<templateMapping>
<mappingItem solutionName="test1" templationName="test1.ftl"></mappingItem>
<mappingItem solutionName="test2" templationName="test2.ftl"></mappingItem>
<mappingItem solutionName="test3" templationName="test3.ftl"></mappingItem>
</templateMapping>
name: ${name}
- 创建测试接口
@ResponseBody
@RequestMapping(value = "/testTemplate", method = RequestMethod.GET)
public String freemarker(Map<String, Object> map, String name){
Map<String, String> templateConfig = FreeMarkerUtils.getTemplateConfig();
Map<String, Object> mode = new HashMap<>();
mode.put("name", name);
String templateName = templateConfig.get("test1");
String result = FreeMarkerUtils.processData(mode, templateName);
return result;
}
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