java開発–SimpleTagインタフェースによるカスタムタグを定義する

2017年1月30日

Javaコード:
public class SimpleTagSupport implements SimpleTag
{
private JspTag parentTag;
private JspContext jspContext;

private JspFragment jspBody;

public SimpleTagSupport() { }

public void doTag() throws JspException, IOException
{
}

public void setParent( JspTag parent ) {
this.parentTag = parent;
}

public JspTag getParent() {
return this.parentTag;
}

public void setJspContext( JspContext pc ) {
this.jspContext = pc;
}

protected JspContext getJspContext() {
return this.jspContext;
}

public void setJspBody( JspFragment jspBody ) {
this.jspBody = jspBody;
}

protected JspFragment getJspBody() {
return this.jspBody;
}

public static final JspTag findAncestorWithClass(
JspTag from, Class<?> klass)
{
boolean isInterface = false;

if (from == null || klass == null
|| (!JspTag.class.isAssignableFrom(klass)
&& !(isInterface = klass.isInterface()))) {
return null;
}

for (;;) {
JspTag parent = null;
if( from instanceof SimpleTag ) {
parent = ((SimpleTag)from).getParent();
}
else if( from instanceof Tag ) {
parent = ((Tag)from).getParent();
}
if (parent == null) {
return null;
}

if (parent instanceof TagAdapter) {
parent = ((TagAdapter) parent).getAdaptee();
}
if ((isInterface && klass.isInstance(parent))
|| klass.isAssignableFrom(parent.getClass())) {
return parent;
}

from = parent;
}
}
}