EL autocomplete / code assist with Eclipse and Spring Beans

问题

In Eclipse, auto-complete for JSF / EL only works for legacy @ManagedBean or CDI beans (@Named), at least when using the JBoss tools plugin.
See also:   EL proposals / autocomplete / code assist in Facelets with Eclipse   or   Eclipse autocomplete (content assist) with facelets (jsf) and xhtml   or   Content Assist for JSF2 + CDI (weld) beans + Eclipse Helios
=> Summing-up:
- install JBoss tools JSF + CDI (http://download.jboss.org/jbosstools/oxygen/stable/updates/, JBoss Web and Java EE / JBoss Tools JSF + Visual Page Editor + Contexts and Dependency Injection Tools);
- in project properties: remove Project Facets/"JavaServer Faces" so the very slow Eclipse JSF-autocompleter will not be used,   activate CDI / CDI support.

But there is no support when using Spring, i.e. @Controller or @Component.
Typically, you should use CDI beans with full support for all JSF scopes now, but you may have your reasons or an existing project may use Spring.
See also:   Moving JSF Managed Beans to Spring beans   or   https://www.beyondjava.net/blog/integrate-jsf-2-spring-3-nicely/

So, how to support JSF/EL auto-complete for Spring web beans?

回答1:

I digged into the JBoss tools implementation and a small change makes Spring users happy.
:-)
There is a solution based on the JSF tools (first) and an alternative based on the CDI tools (afterwards).

The following is based on jbosstools-4.5.2.Final using the plugin file org.jboss.tools.jsf_3.8.200.v20170908-0911.jar
But the changes should be the same or very similar for other versions (the relevant source files have their last changes back in Dec 2011 or Sept 2012).

The class org.jboss.tools.jsf.jsf2.bean.model.impl.AbstractMemberDefinitionhas to be extended in the methods getManagedBeanAnnotation() and isAnnotationPresent():

If @ManagedBean is not found, then also look for @Controller (which should be used in Spring, so @Service etc. is not offered in JSF). But this may easily be adjusted, see comments in the following source. Additionally, Spring uses the value annotation attribute instead of name - this is solved via a wrapper class.

public boolean isAnnotationPresent(String annotationTypeName) {
    //TW: added Spring annotations
    boolean b = (getAnnotation(annotationTypeName) != null);
    if (!b  &&  JSF2Constants.MANAGED_BEAN_ANNOTATION_TYPE_NAME.equals(annotationTypeName)) {
        b = (getAnnotation("org.springframework.stereotype.Controller") != null);
        /* with support for all Spring annotations:
        b = (getAnnotation("org.springframework.stereotype.Controller") != null
                ||  getAnnotation("org.springframework.stereotype.Service") != null
                ||  getAnnotation("org.springframework.stereotype.Repository") != null
                ||  getAnnotation("org.springframework.stereotype.Component") != null);
        */
    }
    return b;
}


public AnnotationDeclaration getManagedBeanAnnotation() {
    AnnotationDeclaration ad = annotationsByType.get(JSF2Constants.MANAGED_BEAN_ANNOTATION_TYPE_NAME);
    //TW: added Spring annotations
    if (ad != null)  return ad;
    ad = annotationsByType.get("org.springframework.stereotype.Controller");
    /* with support for all Spring annotations:
    if (ad == null)  ad = annotationsByType.get("org.springframework.stereotype.Service");
    if (ad == null)  ad = annotationsByType.get("org.springframework.stereotype.Repository");
    if (ad == null)  ad = annotationsByType.get("org.springframework.stereotype.Component");
    */
    if (ad != null) {
        // create wrapper to map "value" (used by Spring) to "name" (which is used by @ManageBean)
        ad = new AnnotationDeclaration() {
                private AnnotationDeclaration wrapped;

                AnnotationDeclaration init(AnnotationDeclaration wrappedAD) {
                    this.wrapped = wrappedAD;
                    return this;
                }

                @Override
                public Object getMemberValue(String name) {
                    Object val = wrapped.getMemberValue(name);
                    if (val == null  &&  "name".equals(name)) {
                        val = wrapped.getMemberValue(null);
                    }
                    return val;
                }

                @Override
                public Object getMemberValue(String name, boolean resolve) {
                    Object result = null;
                    if (resolve) {
                        result = this.getMemberConstantValue(name);
                    }
                    if (result == null) {
                        result = this.getMemberValue(name);
                    }
                    return result;
                }

                @Override
                public void setDeclaration(IJavaAnnotation annotation) {
                    wrapped.setDeclaration(annotation);
                }

                @Override
                public IJavaAnnotation getDeclaration() {
                    return wrapped.getDeclaration();
                }

                @Override
                public IResource getResource() {
                    return wrapped.getResource();
                }

                @Override
                public IMemberValuePair[] getMemberValuePairs() {
                    return wrapped.getMemberValuePairs();
                }

                @Override
                public Object getMemberConstantValue(String name) {
                    return wrapped.getMemberConstantValue(name);
                }

                @Override
                public Object getMemberDefaultValue(String name) {
                    return wrapped.getMemberDefaultValue(name);
                }

                @Override
                public IMember getParentMember() {
                    return wrapped.getParentMember();
                }

                @Override
                public String getTypeName() {
                    return wrapped.getTypeName();
                }

                @Override
                public IType getType() {
                    return wrapped.getType();
                }

                @Override
                public int getLength() {
                    return wrapped.getLength();
                }

                @Override
                public int getStartPosition() {
                    return wrapped.getStartPosition();
                }

                @Override
                public IAnnotationType getAnnotation() {
                    return wrapped.getAnnotation();
                }

                @Override
                public IAnnotation getJavaAnnotation() {
                    return wrapped.getJavaAnnotation();
                }

                @Override
                public IMember getSourceMember() {
                    return wrapped.getSourceMember();
                }

                @Override
                public IJavaElement getSourceElement() {
                    return wrapped.getSourceElement();
                }
            }.init(ad); // class
    }
    return ad;
}

I offer the two compiled classes (main + one inner class) here for direct download:
AbstractMemberDefinition.class + AbstractMemberDefinition$1.class
I promise a trustworthy compile with just above changes (i.e. without any malicious code or similar, you may check via a decompile with CFR, Procyon, aged JAD or Eclipse-ECD) - you may use them directly or perform the compile by yourself (BTW: Does stack overflow offer file attachments?)

Installation:

• Exit Eclipse.
• Make a backup copy of the original file
  eclipse_home\plugins\org.jboss.tools.jsf_3.8.200.v20170908-0911.jar
  (e.g. as *.jar_orig).
• Copy the provided classes into org.jboss.tools.jsf_3.8.200.v20170908-0911.jar\org\jboss\tools\jsf\jsf2\bean\model\impl (e.g. via Total Commander or another tool supporting zip/jar handling; you may even use JDKs jar tool). Note: the A...$1.class is a new file.
• Start Eclipse again and enjoy!

Go to a JSF page and Type Ctrl+Space after #{ to get a list of beans. Member auto-completion works, too (after #{beanName.), even recursive.
Even Ctrl+click or F3 on the bean name works!
Note: the first auto-completion call needs some seconds for the initial bean disovery.

BTW: For this, there is no need to activate CDI support for the project! (Build is quicker then because no CDI Builder is active.)

---

Alternatively, you may extend the JBoss tools CDI feature to discover Spring beans. It works the same and additionally they will be listed with Ctrl+Alt+Z (toolbar button Open CDI Named Bean).
Note: I did not check if there are any side effects if the non-CDI Spring beans are discovered as CDI beans!

For this, the file org.jboss.tools.cdi.internal.core.impl.definition.AbstractMemberDefinition has to be extended in the method getNamedAnnotation():

public AnnotationDeclaration getNamedAnnotation() {
    AnnotationDeclaration ad = getAnnotation(CDIConstants.NAMED_QUALIFIER_TYPE_NAME);
    //TW: added Spring annotations
    if (ad != null)  return ad;
    ad = getAnnotation("org.springframework.stereotype.Controller");
    /* add additional Spring annotations, if desired:
    if (ad != null)  return ad;
    ad = getAnnotation("org.springframework.stereotype.Service");
    if (ad != null)  return ad;
    ad = getAnnotation("org.springframework.stereotype.Repository");
    if (ad != null)  return ad;
    ad = getAnnotation("org.springframework.stereotype.Component");
    */
    return ad;
}

You have to copy the compiled class (download: CDI-AbstractMemberDefinition.class) into plugins\org.jboss.tools.cdi.core_1.8.201.v20171221-1913.jar\org\jboss\tools\cdi\internal\core\impl\definition

CDI support has to be active for the project.

---

Maybe someone working for the JBoss tools project may include this in the offical plugin.
Best would be to offer a preferences String, that allows to add arbitrary annotations - maybe even a project specific setting. This would then be a generic solution and no "offical Spring support" which might have political acceptance issues.
See https://issues.jboss.org/browse/JBIDE-25748

来源：https://stackoverflow.com/questions/48933757/el-autocomplete-code-assist-with-eclipse-and-spring-beans