建立和运行速度生成HTML

Question

I'm very new to using Velocity. 我对使用Velocity非常陌生。 I am trying to use it to generate an HTML form. 我正在尝试使用它来生成HTML表单。 I am working in Eclipse. 我正在Eclipse中工作。 The following jars are in my classpath: 以下jar在我的类路径中：

velocity-dep-1.5.jar
commons-collections.jar
commons-lang.jar
log4j-1.2.8.jar
ant.jar

I am running an ant build file to build my project, but I don't see the HTML being generated. 我正在运行一个蚂蚁构建文件来构建我的项目，但是我看不到正在生成HTML。 Is there something I'm missing in order to get it to actually generate the HTML file? 为了使它真正生成HTML文件，我缺少什么吗？ The tutorial I was following only has two files that I based mine off of. 我遵循的教程只有两个基于我的文件。 It worked for the author, but perhaps there is something else that I don't realize being new to using velocity. 它对作者有用，但也许还有其他我不了解使用速度的东西。 I have included my code and build script to make it easier to see if I'm missing something. 我已经包括了我的代码和构建脚本，以使其更容易查看是否缺少某些内容。 Thank you very much! 非常感谢你！

I have the template code for my form here ( form.vm ): 我在这里有我的表单的模板代码（ form.vm ）：

<html>
<head>
    <title> My Form </title>
</head>

<body>
#if ($fieldErrors)
    #foreach ($error in $fieldErrors)
        $error<br>
    #end
#end
#if ($actionErrors)
    #foreach ($error in $actionErrors)
        $error<br>
    #end
#end

<form name="edit" action="edit.action" method="post">
    <table>
        <tr><td>Testing</td><td>123</td></tr>
        #foreach($map in $radioList)
            #formRowRadio("method" $method "true" $selected)<br/>
        #end
    </table>
    <table>
        #foreach($map in $textList)
            #formRowText($label $label $value)
        #end
        <tr><td>&nbsp;</td><td><input type="submit" name="submit" value="submit"></td></tr>
    </table>

</form>

</body>
</html>

Here is the java code I have to go along with that ( formDemo.java ) 这是我必须遵循的Java代码（ formDemo.java ）

import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.Velocity;
import org.apache.velocity.Template;

public class formDemo {
    public static void main ( String[] args )
        throws Exception {

        Velocity.init();

        ArrayList radioList = new ArrayList();
        Map map = new HashMap();
        map.put("method", "Yes");
        map.put("selected", false);
        radioList.add(map);

        map = new HashMap();
        map.put("method", "No");
        map.put("selected", false);
        radioList.add(map);

        /* 
         * add the list to a VelocityContext
         */
        VelocityContext context = new VelocityContext();
        context.put("radios", radioList);

        ArrayList textList = new ArrayList();
        map = new HashMap();
        map.put("label", "FirstName");
        map.put("value", "");
        textList.add(map);

        map = new HashMap();
        map.put("label", "LastName");
        map.put("value", "");
        textList.add(map);

        context.put("textfields", textList);
        Template template = Velocity.getTemplate("form.vm");
        StringWriter writer = new StringWriter();
        template.merge(context, writer);
    }
 }

Build script ( build.xml ) 生成脚本（ build.xml ）

<?xml version='1.0' encoding='UTF-8'?>
<project name="velocityTemplate" default="jar" basedir=".">

<property name='cls' location='${basedir}/classes'/>
<property name='dat' location='${basedir}/data'/>
<property name='gen' location='${basedir}/gen'/>
<property name='lib' location='${basedir}/lib'/>
<property name='src' location='${basedir}/src'/>
<property name='tmp' location='${basedir}/templates'/>

<path id='project.classpath'>
    <pathelement location='${cls}'/>
    <fileset dir='${lib}' includes='*.jar'/>
</path>    <target name='clean' description='Clean.'>
    <delete dir='${cls}'/>
    <delete dir='${gen}'/>
</target>

<target name='comp' description='Compile the source.'>
    <mkdir dir='${cls}'/>
    <javac srcdir='${src}' destdir='${cls}' classpathref='project.classpath' fork='true'/>
</target>

<target name='jar' depends='comp' description='JAR the application.'>
    <jar destfile='${ant.project.name}.jar' update='false' filesonly='true' index='true'>
        <fileset dir='${cls}'/>
        <fileset dir='${src}'/>
    </jar>
</target>

<target name='run' depends='jar' description='Run the application.'>
    <path id='velocityTemplate.classpath'>
        <pathelement location='${ant.project.name}.jar'/>
        <fileset dir='${lib}' includes='*.jar'/>
    </path>
    <taskdef classpathref='velocityTemplate.classpath'/>
    <mkdir dir='${gen}'/>
    <enumerator outputPath='${gen}' inputPath='${dat}' templateFile='${tmp}/form.vm'/>
</target>

<target name='form' description='Creates form'>
    <path id='velocityTemplate.classpath'>
        <pathelement location='${basedir}/velocityTemplate.jar'/>
        <pathelement location='${lib}/velocity-dep-1.5.jar'/>
    </path>

    <taskdef classpathref='velocityTemplate.classpath'/>
    <velocityTemplate outputPath='${basedir}/src' templateFile='${basedir}/form.vm'/>
</target>

</project>

Answer 1

If you just want to see the html being generated, you'll have to print out the value of the StringWriter or write it to a file. 如果只想查看正在生成的html，则必须打印出StringWriter的值或将其写入文件。

Currently, unless there's code missing, you're just filling up the buffer. 当前，除非缺少代码，否则您只是在填充缓冲区。

    Template template = Velocity.getTemplate("form.vm");
    StringWriter writer = new StringWriter();
    template.merge(context, writer);

template.merge(context, writer) just renders the template to the StringWriter object. template.merge（context，writer）只是将模板呈现给StringWriter对象。

Answer 2

I think your template should be as the following: 我认为您的模板应如下所示：

<html>
<head>
    <title> My Form </title>
</head>

<body>
#if ($fieldErrors)
    #foreach ($error in $fieldErrors)
        $error<br>
    #end
#end
#if ($actionErrors)
    #foreach ($error in $actionErrors)
        $error<br>
    #end
#end

<form name="edit" action="edit.action" method="post">
    <table>
        <tr><td>Testing</td><td>123</td></tr>
        #foreach($map in $radios)
            #formRowRadio("method" $map.method "true" $map.selected)<br/>
        #end
    </table>
    <table>
        #foreach($map in $textfields)
            #formRowText($map.label $map.label $map.value)
        #end
        <tr><td>&nbsp;</td><td><input type="submit" name="submit" value="submit"></td></tr>
    </table>

</form>

</body>
</html>

And you also need to effectively print the StringWriter to a File.html. 而且，您还需要有效地将StringWriter打印到File.html。

Answer 3

In the code you posted: there 2 ways to run velocity: 在您发布的代码中：有两种运行速度的方法：

running the main (but this is not what you do when you build your project) 运行主程序（但这不是在构建项目时要执行的操作）
running ant form but since you don't fill any velocity context: velocity won't be able to replace the variable in your template (ie the generated html won't contains dynamic data) 运行ant form但是由于您没有填写任何速度上下文：Velocity将无法替换模板中的变量（即，生成的html将不包含动态数据）

I'm not sure what you need: 我不确定您需要什么：

Is it using velocity at build time ? 在构建时是否使用速度？ In this case you have to run ant form and then ant run (or add a depends="form" in comp target). 在这种情况下，您必须先运行ant form ，然后再ant run （或在comp目标中添加depends =“ form”）。 But you also have to provide a velocity context to velocity in the build.xml 但是您还必须在build.xml中提供一个速度上下文给速度

If you need to run velocity at runtime: just use a file writer to perfom the velocity merge. 如果需要在运行时运行速度：只需使用文件编写器执行速度合并。

Answer 4

It looks like your build script is not actually executing the Java code. 看起来您的构建脚本实际上并未执行Java代码。

Try using the java ant task, see here: 尝试使用Java ant任务，请参见此处：

Ant Java task Ant Java任务

建立和运行速度生成HTML

问题描述

4 个解决方案

解决方案1
0 已采纳 2013-09-27 15:41:17

解决方案2
0 2013-09-27 15:43:03

解决方案3
0 2013-09-27 16:32:29

解决方案4
0 2013-09-27 16:36:55

建立和运行速度生成HTML

问题描述

4 个解决方案

解决方案1 0 已采纳 2013-09-27 15:41:17

解决方案2 0 2013-09-27 15:43:03

解决方案3 0 2013-09-27 16:32:29

解决方案4 0 2013-09-27 16:36:55

解决方案1
0 已采纳 2013-09-27 15:41:17

解决方案2
0 2013-09-27 15:43:03

解决方案3
0 2013-09-27 16:32:29

解决方案4
0 2013-09-27 16:36:55