JET2简单例子
1.JET生成java代码：
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下列实例是一个模板，用于创建拥有任意数量属性的类。每个属性将有 getter 和 setter 与之关联，还有一些初始值。此外，所调用的函数的名称将输出到命令行，通过这种方式，模板即可为各函数添加简单的日志。
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class <c:get select="/app/@class" /> {<c:iterate select="/app/property" var="p" >private <c:get select="$p/@type" /> <c:get select="$p/@name" />;</c:iterate>public <c:get select="/app/@class" />() {<c:iterate select="/app/property" var="p" >this.<c:get select="$p/@name" /> = <c:choose select="$p/@type" ><c:when test="'String'">"<c:get select="$p/@initial" />"</c:when><c:otherwise><c:get select="$p/@initial" /></c:otherwise></c:choose>;</c:iterate>}<c:iterate select="/app/property" var="p" >public void set<c:get select="camelCase($p/@name)" />(<c:get select="$p/@type" /><c:get select="$p/@name" />) {System.out.println\("In set<c:get select="camelCase($p/@name)" />()");this.<c:get select="$p/@name" /> = <c:get select="$p/@name" />;}public <c:get select="$p/@type" /> get<c:get select="camelCase($p/@name)" />() {System.out.println("In get<c:get select="camelCase($p/@name)" />()");return <c:get select="$p/@name" />;}</c:iterate>}?
这里是该模板的输入模型实例：
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<app type="String" initial="Honda Accord" /><property name="horsepower" type="int" initial="140" /><property name="spareTires" type="boolean" initial="true" /></app>
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这些输入参数生成如下类：
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class Car {private String model;private int horsepower;private boolean spareTires;public Car() {this.model = "Honda Accord";this.horsepower = 140;this.spareTires = true;}public void setModel(String model) {System.out.println("In setModel()");this.model = model;}public String getModel() {System.out.println("In getModel()");return model;}public void setHorsepower(int horsepower) {System.out.println("In setHorsepower()");this.horsepower = horsepower;}public int getHorsepower() {System.out.println("In getHorsepower()");return horsepower;}public void setSparetires(boolean spareTires) {System.out.println("In setSparetires()");this.spareTires = spareTires;}public boolean getSparetires() {System.out.println("In getSparetires()");return spareTires;}}?
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2.JET生成其他代码：
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为强调 JET 不仅仅可用来生成代码，我们给出了下面这个实例，这是一个模板，生成具有不同语气的电子邮件消息。所生成的各电子邮件的目的是是向某人索要求各种东西。下面提供控制文件（main.jet）及其调用的模板（email.jet）。
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main.jet
<c:iterate select="/app/email" var="currEmail" ><ws:file template="templates/email.jet"path="{$org.eclipse.jet.resource.project.name}/{$currEmail/@to}.txt" /></c:iterate>?
email.jet
<c:setVariable var="numItems" select="0" /><c:iterate select="$currEmail/request" var="r"><c:setVariable var="numItems" select="$numItems+1" /></c:iterate><c:set select="$currEmail" name="numItems"><c:get select="$numItems" /></c:set><c:choose select="$currEmail/@mood" ><c:when test="'happy'">My dear</c:when><c:when test="'neutral'">Dear</c:when><c:when test="'angry'">My enemy</c:when></c:choose> <c:get select="$currEmail/@to" />,I am writing you <c:choose select="$currEmail/@mood" ><c:when test="'happy'">in joy </c:when><c:when test="'neutral'"></c:when><c:when test="'angry'">in burning anger </c:when></c:choose>to ask for <c:choose select="$currEmail/@numItems" ><c:when test="1">a <c:get select="$currEmail/request/@item" />. </c:when><c:otherwise>the following:<c:setVariable var="i" select="0" /><c:iterate select="$currEmail/request" var="r"><c:setVariable var="i" select="$i+1" /><c:get select="$i" />. <c:get select="$r/@item" /></c:iterate></c:otherwise></c:choose><c:choose select="$currEmail/@mood"><c:when test="'happy'">Please</c:when><c:when test="'neutral'">Please</c:when><c:when test="'angry'">Either suffer my wrath, or</c:when></c:choose> send me <c:choose select="$currEmail/@numItems"><c:when test="1">this item</c:when><c:otherwise>these items</c:otherwise></c:choose> <c:choose select="$currEmail/@mood" ><c:when test="'happy'">at your earliest convenience.</c:when><c:when test="'neutral'">promptly.</c:when><c:when test="'angry'">immediately!</c:when></c:choose><c:choose select="$currEmail/@mood" ><c:when test="'happy'">Your friend,</c:when><c:when test="'neutral'">Sincerely,</c:when><c:when test="'angry'">In rage,</c:when></c:choose><c:get select="/app/@from" />
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该模板的输入模型实例如下：
sample.xml
<app from="Nathan" ><email to="Chris" mood="angry" ><request item="well-written article" /></email><email to="Nick" mood="happy" ><request item="Piano" /><request item="Lollipop" /><request item="Blank DVDs" /></email></app>
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将?mood?电子邮件蓝图应用于这些参数，生成下列两个文件。
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