Velocity can't find resource

问题:

Something is wrong and it is very frustrating. I read on velocity's homepage that when I run a webapp then some properties should be set. And I've done that but no matter what I do I keep getting the same error.
This is where I set the props and use velocity

public class ConfirmationMailGenerator implements MailGenerator {

    private BasicUser user;
    private String htmlTemplate = "HTMLConfirmationMailTemplate.vsl";
    private String plainTemplate = "PlainConfirmationMailTemplate.vsl";

    public ConfirmationMailGenerator(BasicUser user) {
        this.user = user;
    }

    public StringWriter generateHTML() throws Exception {
        Properties props = new Properties();
        props.setProperty("resource.loader", "wepapp");
        props.setProperty("webapp.resource.loader.class", "org.apache.velocity.tools.view.WebappResourceLoader");
        props.setProperty("webapp.resource.loader.path", "/WEB-INF/mailtemplates/");
        VelocityEngine engine = new VelocityEngine(props);
        VelocityContext context = new VelocityContext();

        engine.init();

        Map map = createDataModel();
        context.put("user", map);

        Template template = engine.getTemplate(htmlTemplate);
        StringWriter writer = new StringWriter();
        template.merge(context, writer);

        return writer;
    }
...
}

The files is of course saved in /WEB-INF/mailtemplates/.
If I use this I get this error:

SEVERE: ResourceManager : unable to find resource 'HTMLConfirmationMailTemplate.vsl' in any resource loader.
SEVERE: The log message is null.

Thank you for your time:)

回答1:

You are using the Webapp resourceloader, which is intended for pages served by the Velocity Tools servlet. (It requires some special initialization to find the root of the servlet context).

I recommend you use the ClasspathResourceLoader, then put the files into WEB-INF/classes, or elsewhere in your classpath. This is really the most straight forward approach.

resource.loader = class
class.resource.loader.class = org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader

More info is here:

https://velocity.apache.org/engine/1.7/apidocs/org/apache/velocity/runtime/resource/loader/ClasspathResourceLoader.html

回答2:

Will Glass answer is correct, but the configuration should be:

resource.loader = class
class.resource.loader.class = org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader

Note the class at the beginning of the second line. See the links provided by him for more details!.

Note: Making an answer instead of a comment due to privileges.

回答3:

Velocity is probably using the class loader to find those files. I'd recommend putting them in WEB-INF/classes, which is in the CLASSPATH by default.

回答4:

I am fine it as follow,

In velocity.properties file

resource.loader=class, file
class.resource.loader.class=org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader
file.resource.loader.class=org.apache.velocity.runtime.resource.loader.FileResourceLoader
file.resource.loader.path=vm_template
runtime.log.logsystem.class=org.apache.velocity.runtime.log.SimpleLog4JLogSystem
runtime.log.logsystem.log4j.category=velocity
input.encoding=UTF-8
output.encoding=UTF-8

And at my java class

import java.io.StringWriter;
import java.util.Properties;
import org.apache.log4j.Logger;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.Velocity;
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.tools.generic.DateTool;
import org.apache.velocity.tools.generic.EscapeTool;
import org.apache.velocity.tools.generic.LoopTool;
import org.apache.velocity.tools.generic.MathTool;
import org.apache.velocity.tools.generic.NumberTool;
import org.apache.velocity.tools.generic.SortTool;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;

public class VelocitySupport implements InitializingBean {
private static Logger log = Logger.getLogger(VelocitySupport.class);

@Autowired private Properties properties;

public final void afterPropertiesSet() throws Exception {
    location = location.replace("classpath:", "");
    Resource res = new ClassPathResource(location);

    Properties prop = new Properties();
    prop.load(res.getInputStream());

    String staticDir = System.getProperty("staticDir");
    String tempPath = prop.getProperty("file.resource.loader.path");
    tempPath = staticDir + "/" + tempPath;

    prop.setProperty("file.resource.loader.path", tempPath);
    Velocity.init(prop);
}

public static String merge(final String template, final VelocityContext vc) throws Exception {
    try {
        vc.put("date", new DateTool());
        vc.put("escape", new EscapeTool());
        vc.put("math", new MathTool());
        vc.put("number", new NumberTool());
        vc.put("iterate", new LoopTool());
        vc.put("sort", new SortTool());

        Template temp = Velocity.getTemplate(template);

        StringWriter sw = new StringWriter();
        temp.merge(vc, sw);
        sw.flush();

        return sw.toString();
    }
    catch (ResourceNotFoundException e) {
        log.error("", e);
        throw e;
    }
    catch (ParseErrorException e) {
        log.error("", e);
        throw e;
    }
}

private String location;

public final void setLocation(final String location) {
    this.location = location;
}
}

And insert VM arguments of project as follow..

-DstaticDir= "your directory for template path"

That may be helpful for you...

回答5:

For resolving this error --WEB-INF/classes and all the JARs in WEB-INF/lib are in the CLASSPATH. Try moving your folder with the .vm files under WEB-INF/classes --dont put the abolute path eg. if abc.vm file is in /public_html/WEB-INF folder then put path = "/public_html/WEB-INF/abc.vm" for velocity template path.