Freemarker模板文件返回字符串

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     首先，先创建一个ftl文件:
   

Hello ${name}(${getUserAge(name)})

    之后，创建一个java应用程序类:
  

package freemarker;

import java.io.File;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import freemarker.template.Configuration;
import freemarker.template.DefaultObjectWrapper;
import freemarker.template.Template;
import freemarker.template.TemplateException;

/**
 * 
 * @Desc 获取FTL文件生成的字符串，以供调用
 * @author xujp1
 * @version Revision: 1.00 Date: May 9, 2012
 */
public class GenerateStringFromFtl
{

    private static Configuration conf = null;

    public static void main(String args[])
    {
        conf = new Configuration();
        try
        {
            conf.setDirectoryForTemplateLoading(new File("WebRoot/WEB-INF/template"));
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        conf.setObjectWrapper(new DefaultObjectWrapper());
        conf.setLocale(Locale.CHINA);
        conf.setSharedVariable("getUserAge", new GetUserAge());//自定义方法供调用
        conf.setDefaultEncoding("utf-8");
        conf.setClassicCompatible(true);//处理空值为空字符串
        String tempReturn = "";
        Map root = new HashMap();
        String name = "xujp1";
        root.put("name", name);
        try
        {
            tempReturn = generateHtmlFromFtl(root, "hellouser.ftl");
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        catch (TemplateException e)
        {
            e.printStackTrace();
        }
        System.out.println(tempReturn);
    }

    public static String generateHtmlFromFtl(Object root, String tempPath) throws IOException, TemplateException
    {
        Template temp = conf.getTemplate(tempPath);
        Writer out = new StringWriter(2048);
        temp.process(root, out);
        return out.toString();
    }
}

    由于有用到自定义方法，因此在建个方法类：
  

package freemarker;

import java.util.List;

import freemarker.template.SimpleScalar;
import freemarker.template.TemplateMethodModel;
import freemarker.template.TemplateModelException;

/**
 * 
 * @Desc freemarker中使用的方法，根据传入的参数返回相应的值
 * @author xujp1
 * @version Revision: 1.00 Date: May 9, 2012
 */
public class GetUserAge implements TemplateMethodModel
{

    /* (non-Javadoc)
     * @see freemarker.template.TemplateMethodModel#exec(java.util.List)
     */
    @SuppressWarnings("unchecked")
    @Override
    public Object exec(List args) throws TemplateModelException
    {
        if(args.size() != 1)
        {
            throw new TemplateModelException("Wrong arguments!");
        }
        int age = 0;
        if("xujp1".equalsIgnoreCase((String)args.get(0)))
            age = 25;
        else
            age = 24;
        return new SimpleScalar(String.valueOf(age));
    }
}

   运行后，得到所要的结果