Java Velocity類代碼示例

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
/**
 * 根據模板生成文件
 * @param inputVmFilePath 模板路徑
 * @param outputFilePath 輸出文件路徑
 * @param context
 * @throws Exception
 */
public static void generate(String inputVmFilePath, String outputFilePath, VelocityContext context) throws Exception {
	try {
		Properties properties = new Properties();
		properties.setProperty(VelocityEngine.FILE_RESOURCE_LOADER_PATH, getPath(inputVmFilePath));
		Velocity.init(properties);
		//VelocityEngine engine = new VelocityEngine();
		Template template = Velocity.getTemplate(getFile(inputVmFilePath), "utf-8");
		File outputFile = new File(outputFilePath);
		FileWriterWithEncoding writer = new FileWriterWithEncoding(outputFile, "utf-8");
		template.merge(context, writer);
		writer.close();
	} catch (Exception ex) {
		throw ex;
	}
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
@Inject
public VelocityDefaultConfigurationFactory(@Optional final ServletContext servletContext) {
    String loader = "class";
    Velocity.setProperty("class.resource.loader.class", ClasspathResourceLoader.class.getName());
    Velocity.setProperty(RuntimeConstants.FILE_RESOURCE_LOADER_CACHE, "true");

    if (servletContext != null) {
        Velocity.setProperty("webapp.resource.loader.class", WebappResourceLoader.class.getName());
        Velocity.setProperty("webapp.resource.loader.path", "/");
        Velocity.setApplicationAttribute("javax.servlet.ServletContext", servletContext);
        loader += ",webapp";
    }
    Velocity.setProperty(RuntimeConstants.RESOURCE_LOADER, loader);

    configuration = new Configuration();
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
public void usage1(String inputFile) throws FileNotFoundException {
   Velocity.init();

    VelocityContext context = new VelocityContext();

    context.put("author", "Elliot A.");
    context.put("address", "217 E Broadway");
    context.put("phone", "555-1337");

    FileInputStream file = new FileInputStream(inputFile);

    //Evaluate
    StringWriter swOut = new StringWriter();
    Velocity.evaluate(context, swOut, "test", file);

    String result =  swOut.getBuffer().toString();
    System.out.println(result);
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
@Override
public String createTable(Grammar grammar) {
    Velocity.setProperty(RuntimeConstants.OUTPUT_ENCODING, "UTF-8");
    Velocity.setProperty(RuntimeConstants.INPUT_ENCODING, "UTF-8");
    Velocity.setProperty(RuntimeConstants.RESOURCE_LOADER, "classpath");
    Velocity.setProperty("classpath.resource.loader.class", ClasspathResourceLoader.class.getName());

    Velocity.init();
    VelocityContext context = new VelocityContext();
    context.put("grammar", grammar);

    context.put("nonterminalSymbols", grammar.getLhsSymbols());

    Template template = Velocity.getTemplate("/grammartools/PredictiveParsingTable.velo");
    StringWriter stringWriter = new StringWriter();
    template.merge(context, stringWriter);
    return stringWriter.toString().replaceAll("\n", "");
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
public void outputCode(String codePath, String templatePath) throws IOException {
    VelocityContext context = new VelocityContext();
    context.put("cModule", cModule);

    Template template = null;
    try {
        template = Velocity.getTemplate(templatePath, TEMPLATE_ENCODING);
    } catch (ResourceNotFoundException e) {
        throw e;
    }
    
    File file = new File(codePath);
    logger.info("Generating {} ({})", file.getName(), templatePath);

    PrintWriter pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), OUTPUT_ENCODING)));
    template.merge(context, pw);
    pw.close();
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
/**
 * Gets the template by viewname, the viewname is relative path
 * 
 * @param viewname
 *          the relative view path name
 * @param allowEmpty
 *          if not presented, allow using a empty
 * @return Template
 * @throws IOException
 */
private Template getTemplate(File f) throws IOException {

  String fullname = f.getCanonicalPath();
  T t = cache.get(fullname);

  if (t == null || t.last != f.lastModified()) {

    /**
     * get the template from the top
     */
    Template t1 = Velocity.getTemplate(fullname, "UTF-8");
    t = T.create(t1, f.lastModified());

    cache.put(fullname, t);
  }

  return t == null ? null : t.template;

}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
private void showTasks(HttpServletRequest request, HttpServletResponse response, Collection<TaskRecord> tasks, String title, boolean showDbStats)
        throws IOException {
    if ("json".equals(request.getParameter("format"))) {
        response.setContentType("text/plain");
    } else {
        response.setContentType("text/html");
    }
    int offset = getOffset(request);
    int length = getLength(request);
    // Create Velocity context
    VelocityContext context = new VelocityContext();
    context.put("tasks", tasks);
    context.put("title", title);
    context.put("reportStore", metadata);
    context.put("request", request);
    context.put("offset", offset);
    context.put("length", length);
    context.put("lastResultNum", offset + length - 1);
    context.put("prevOffset", Math.max(0, offset - length));
    context.put("nextOffset", offset + length);
    context.put("showStats", showDbStats);
    context.put("JSON_DATE_FORMAT", JSON_DATE_FORMAT);
    context.put("HTML_DATE_FORMAT", HTML_DATE_FORMAT);
    context.put("PAGE_LENGTH", PAGE_LENGTH);
    // Return Velocity results
    try {
        Velocity.mergeTemplate("tasks.vm", "UTF-8", context, response.getWriter());
        response.setStatus(HttpServletResponse.SC_OK);
    } catch (Exception e) {
        LOG.warn("Failed to display tasks.vm", e);
        response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Failed to display tasks.vm");
    }
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
@Inject
public VelocityViewProcessor(final javax.ws.rs.core.Configuration config, final ServiceLocator serviceLocator,
                             @Optional final ServletContext servletContext) {
    super(config, servletContext, "velocity", "vm");

    this.factory = getTemplateObjectFactory(serviceLocator, VelocityConfigurationFactory.class,
            new Value<VelocityConfigurationFactory>() {
                @Override
                public VelocityConfigurationFactory get() {
                    Configuration configuration = getTemplateObjectFactory(serviceLocator, Configuration.class,
                            Values.<Configuration>empty());
                    if (configuration == null) {
                        return new VelocityDefaultConfigurationFactory(servletContext);
                    } else {
                        return new VelocitySuppliedConfigurationFactory(configuration);
                    }
                }
            });
    Velocity.init();
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
protected void parseTemplateAndRunExpect(String expectTemplateName, Map<String, String> contextVars) throws IOException, InterruptedException {
    VelocityContext context = new VelocityContext();
    for (Map.Entry<String, String> ent : contextVars.entrySet()) {
        context.put(ent.getKey(), ent.getValue());
    }

    Template template = Velocity.getTemplate(expectTemplateName);
    String inputPath = EXPECT_DIR + File.separator + expectTemplateName;
    String outputPath = inputPath.substring(0, inputPath.length() - 3);

    Writer output = new FileWriter(outputPath);
    template.merge(context, output);
    output.close();

    expect(ZIPFILE_EXTRACTED, outputPath);
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
@Override
protected void __doViewInit(IWebMvc owner) {
    super.__doViewInit(owner);
    // 初始化Velocity模板引擎配置
    if (!__inited) {
        __velocityConfig.setProperty(Velocity.ENCODING_DEFAULT, owner.getModuleCfg().getDefaultCharsetEncoding());
        __velocityConfig.setProperty(Velocity.INPUT_ENCODING, owner.getModuleCfg().getDefaultCharsetEncoding());
        __velocityConfig.setProperty(Velocity.OUTPUT_ENCODING, owner.getModuleCfg().getDefaultCharsetEncoding());
        //
        if (__baseViewPath.startsWith("/WEB-INF")) {
            __velocityConfig.setProperty(Velocity.FILE_RESOURCE_LOADER_PATH, new File(RuntimeUtils.getRootPath(), StringUtils.substringAfter(__baseViewPath, "/WEB-INF/")).getPath());
        } else {
            __velocityConfig.setProperty(Velocity.FILE_RESOURCE_LOADER_PATH, __baseViewPath);
        }
        //
        Velocity.init(__velocityConfig);
        //
        __inited = true;
    }
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
private Set<String> prepareVelocityTemplate(String template) throws PIPException {
    VelocityContext vctx = new VelocityContext();
    EventCartridge vec = new EventCartridge();
    VelocityParameterReader reader = new VelocityParameterReader();
    vec.addEventHandler(reader);
    vec.attachToContext(vctx);

    try {
        Velocity.evaluate(vctx, new StringWriter(), "LdapResolver", template);
    } catch (ParseErrorException pex) {
        throw new PIPException("Velocity template preparation failed", pex);
    } catch (MethodInvocationException mix) {
        throw new PIPException("Velocity template preparation failed", mix);
    } catch (ResourceNotFoundException rnfx) {
        throw new PIPException("Velocity template preparation failed", rnfx);
    }
    if (this.logger.isTraceEnabled()) {
        this.logger.trace("(" + id + ") " + template + " with parameters " + reader.parameters);
    }

    return reader.parameters;
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
private String evaluateVelocityTemplate(String template,
                                        final Map<String, PIPRequest> templateParameters,
                                        final PIPFinder pipFinder)
    throws PIPException {
    StringWriter out = new StringWriter();
    VelocityContext vctx = new VelocityContext();
    EventCartridge vec = new EventCartridge();
    VelocityParameterWriter writer = new VelocityParameterWriter(pipFinder, templateParameters);
    vec.addEventHandler(writer);
    vec.attachToContext(vctx);

    try {
        Velocity.evaluate(vctx, out, "LdapResolver", template);
    } catch (ParseErrorException pex) {
        throw new PIPException("Velocity template evaluation failed", pex);
    } catch (MethodInvocationException mix) {
        throw new PIPException("Velocity template evaluation failed", mix);
    } catch (ResourceNotFoundException rnfx) {
        throw new PIPException("Velocity template evaluation failed", rnfx);
    }

    this.logger.warn("(" + id + ") " + " template yields " + out.toString());

    return out.toString();
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
public static String doMerge(String strToMerge, Map map) {
  if (strToMerge == null)
    return null;

  try {

    // ask Velocity to evaluate it.
    Velocity.init();
    StringWriter w = new StringWriter();
    VelocityContext context = new VelocityContext(map);
    Velocity.evaluate(context, w, "logTag", strToMerge);
    return w.getBuffer().toString();

  } catch (Exception e) {
    return null;
  }
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
/**
 * Wrapper for {@link Velocity#evaluate(org.apache.velocity.context.Context, java.io.Writer, String, java.io.InputStream)}
 *
 * @param templateReader A {@link Reader} of a Velocity template.
 * @param variables Variables to add to context
 * @param logTag The log tag
 *
 * @return {@link String} result of evaluation
 */
public String evaluate(Reader templateReader, Map<String, Object> variables, String logTag)
{
    VelocityContext velocityContext = new VelocityContext(variables);
    StringWriter writer = new StringWriter();
    if (!Velocity.evaluate(velocityContext, writer, logTag, templateReader))
    {
        // Although the Velocity.evaluate method's Javadoc states that it will return false to indicate a failure when the template couldn't be
        // processed and to see the Velocity log messages for more details, upon examining the method's implementation, it doesn't look like
        // it will ever return false. Instead, other RuntimeExceptions will be thrown (e.g. ParseErrorException).
        // Nonetheless, we'll leave this checking here to honor the method's contract in case the implementation changes in the future.
        // Having said that, there will be no way to JUnit test this flow.
        throw new IllegalStateException("Error evaluating velocity template. See velocity log message for more details.");
    }
    return writer.toString();
}
 

import org.apache.velocity.app.Velocity; //導入依賴的package包/類
/**
 * Simply initialize the Velocity engine
 */
@PostConstruct
public void start() throws Exception
{
	try
	{
		Velocity.setProperty(Velocity.RESOURCE_LOADER, "cp");
		Velocity.setProperty("cp.resource.loader.class", "org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");
		Velocity.setProperty("cp.resource.loader.cache", "true");
		Velocity.setProperty("cp.resource.loader.modificationCheckInterval ", "0");
		Velocity.setProperty("input.encoding", "UTF-8");
		Velocity.setProperty("output.encoding", "UTF-8");
		// Very busy servers should increase this value. Default: 20
		// Velocity.setProperty("velocity.pool.size", "20");
		Velocity.setProperty("runtime.log.logsystem.class", "org.apache.velocity.runtime.log.JdkLogChute");
		Velocity.init();
		log.log(Level.FINE,"Velocity initialized!");
	}
	catch (Exception ex)
	{
		log.log(Level.SEVERE,"Unable to initialize Velocity", ex);
		throw new RuntimeException(ex);
	}
}