EJB3笔记10-EJB3 Framwork：实作基于annotation生成代码

EJB3笔记10-EJB3 Framwork：实作基于annotation生成代码
Author fancyhf@163.com fancyhf.mblogger.cn

基于《笔记9》的理论，建立一个可以根据annotaion生成java代码的类。
首先，定义一个AnnotationProcessorFactory类TestApt.java。
/*
* This class is used to run an annotation processor that gen command class
* which annotation with CommandClass.
*/
public class TestApt implements AnnotationProcessorFactory {
// Process any set of annotations
private static final Collection<String> supportedAnnotations
= unmodifiableCollection(Arrays.asList("test.CommandClass"));

// No supported options
private static final Collection<String> supportedOptions = emptySet();

public Collection<String> supportedAnnotationTypes() {
return supportedAnnotations;
}

public Collection<String> supportedOptions() {
return supportedOptions;
}

public AnnotationProcessor getProcessorFor(
Set<AnnotationTypeDeclaration> atds,
AnnotationProcessorEnvironment env) {
return new TestApt Process(env);
}

private static class TestApt Process implements AnnotationProcessor {
private final AnnotationProcessorEnvironment env;

TestApt Process(AnnotationProcessorEnvironment env) {
this.env = env;
}

public void process() {
for (TypeDeclaration typeDecl : env.getSpecifiedTypeDeclarations()) {
typeDecl.accept(getDeclarationScanner(
new ListClassVisitor(env),
NO_OP));
}
}
// ListClassVisitor will process the CommandClass annotation in the given sorce file
private static class ListClassVisitor extends SimpleDeclarationVisitor {
private AnnotationProcessorEnvironment env = null;

public ListClassVisitor(AnnotationProcessorEnvironment env) {
super();
this.env = env;
}

// process all classes tha tag CommandClass
public void visitClassDeclaration(ClassDeclaration d) {
processCmdAnno(d,env);
}

//process all interfaces tha tag CommandClass
public void visitInterfaceDeclaration(InterfaceDeclaration d) {
processCmdAnno(d,env);
}

public String extractFullPakcageName(String className ) {
int index;

if( (index = className.lastIndexOf('.')) != -1 )
return className.substring(0, index);

return className;
}

public void processCmdAnno(TypeDeclaration d, AnnotationProcessorEnvironment env)
CommandClass ann = d.getAnnotation(CommandClass.class);
if (ann != null){
String clsName = d.getQualifiedName();
System.out.println("the clsName is " + clsName);
String packageName = extractFullPakcageName(clsName);
String className = d.getSimpleName();
for (MethodDeclaration f : d.getMethods()) {
Command annotation = f.getAnnotation( Command.class );
if (annotation != null) {
try {
PrintWriter writer =
env.getFiler().createSourceFile(
packageName + ".command." +
className);
writer.println("package "+getCommandPackageName() + ".command;");

writer.println("");
writer.println("//generated class,do not to remove it.");

writer.println("public final class " + getCommandClassName() + " implements Command {");
for (ParameterDeclaration pd : method.getParameters() ) {
String pkgName = "";
String typeName = "";
pkgName = EaUtil.extractFullPakcageName(pd.getType().toString());
typeName = EaUtil.extractNameFromClassName(pd.getType().toString());
System.out.println("the pkgName is " + typeName);
if (!importedPackage.contains(pkgName + ".*")) {
importedPackage.add(pkgName + ".*");
}
String tpName = "";
tpName = EaUtil.extractNameFromClassName(pd.getType().toString());
cnstrPm += tpName + " " + pd.getSimpleName() + ",";
pmValues += pd.getSimpleName() + ",";
writer.println("");
writer.println(" private " + tpName + " " + pd.getSimpleName()+";");
writer.println("");
writer.println(" public " + tpName + " get" + EaUtil.fstStrToUpperCase(pd.getSimpleName())
+ "() {");
writer.println(" return " + pd.getSimpleName() + ";");
writer.println(" }");
writer.println("");
writer.println(" public void set" + EaUtil.fstStrToUpperCase(pd.getSimpleName())
+ "(" + tpName + " " + pd.getSimpleName() +") {");
writer.println(" this." + pd.getSimpleName() + " = " + pd.getSimpleName() + ";");
writer.println(" }");
}
writer.println("}");
writer.close();
} catch (IOException oe) {
env.getMessager().printError(oe.getMessage());
}
}
}

}
}

}

}