Java JSTL-添加要调用的参数

我在JSTL中有以下代码，用于检索j2ee站点中的学生图片

 <c:if test="${student.studentPictureId != null}">
        <a href="javascript:showImage('<c:out value="${student.studentId}"/>','<c:out value="${student.studentPictureId }"/>
</c:if>

我想用枚举调用泛型函数：
学生类上的函数签名如下所示：

  Student class  
           String getPictureId(PictureTypeEnum picture type)

因此，最终的JSTL代码如下所示：

  <c:if test="${student.getPictureId(PictureTypeEnum.StudentCard) != null}">
        <a href="javascript:showImage('<c:out value="${student.studentId}"/>','<c:out value="${student.getPictureId(PictureTypeEnum.StudentCard)}"/>
</c:if>

直接从JSTL调用方法是不可能的，所以我使用了一种技巧：快速映射：

public abstract class QuickMap<K,V> implements Map<K,V> {
    @Override
    public abstract V get(Object key);

    @Override
    public final int size() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final boolean isEmpty() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final boolean containsKey(Object key) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final boolean containsValue(Object value) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final V put(K key, V value) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final V remove(Object key) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final void putAll(Map<? extends K, ? extends V> m) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final void clear() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final Set<K> keySet() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final Collection<V> values() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final Set<Entry<K, V>> entrySet() {
        throw new UnsupportedOperationException("Not supported yet.");
    }
}

public抽象类QuickMap实现Map{
@凌驾
公共抽象V-get（对象键）；
@凌驾
公共最终整数大小（）{
抛出新的UnsupportedOperationException（“尚未支持”）；
}
@凌驾
公共最终布尔值isEmpty（）{
抛出新的UnsupportedOperationException（“尚未支持”）；
}
@凌驾
公共最终布尔containsKey（对象键）{
抛出新的UnsupportedOperationException（“尚未支持”）；
}
@凌驾
公共最终布尔值containsValue（对象值）{
抛出新的UnsupportedOperationException（“尚未支持”）；
}
@凌驾
公共最终V输入（K键，V值）{
抛出新的UnsupportedOperationException（“尚未支持”）；
}
@凌驾
公共最终V删除（对象密钥）{
抛出新的UnsupportedOperationException（“尚未支持”）；
}
@凌驾
公共最终void putAll（mapel2.2）于2009年推出，并在本机上支持它。请继续前进并赶上版本。如何升级eclipse项目？
 <c:out value="${student.studentPictureId }"/>

public abstract class QuickMap<K,V> implements Map<K,V> {
    @Override
    public abstract V get(Object key);

    @Override
    public final int size() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final boolean isEmpty() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final boolean containsKey(Object key) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final boolean containsValue(Object value) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final V put(K key, V value) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final V remove(Object key) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final void putAll(Map<? extends K, ? extends V> m) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final void clear() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final Set<K> keySet() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final Collection<V> values() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public final Set<Entry<K, V>> entrySet() {
        throw new UnsupportedOperationException("Not supported yet.");
    }
}

public Map<Object,String> getStudentPictureIds() {
    return new QuickMap<Object,String>() {
        @Override
        public String get(Object k) {
            PictureTypeEnum type;
            if (k instanceof PictureTypeEnum) {
                type = (PictureTypeEnum)k; 
            } else {
                type = PictureTypeEnum.valueOf(k.toString());
            }
            return getStudentPictureId(type);
        }            
    };
}

<c:out value="${student.pictureIds['StudentCard']}"/>