java注解的实现原理（2）

在上文中主要概括介绍了自定义注解的实现原理，本文将主要介绍通过getAnnotation（）使用动态代理生成注解对应代理类的源码实现过程。

cls.getAnnotation(注解.class);

private static Annotation parseAnnotation2(ByteBuffer var0, ConstantPool var1, Class<?> var2, boolean var3, Class<? extends Annotation>[] var4) {
        int var5 = var0.getShort() & '\uffff';
        Class var6 = null;
        String var7 = "[unknown]";

        try {
            try {
                var7 = var1.getUTF8At(var5);
                var6 = parseSig(var7, var2);
            } catch (IllegalArgumentException var18) {
                var6 = var1.getClassAt(var5);
            }
        } catch (NoClassDefFoundError var19) {
            if (var3) {
                throw new TypeNotPresentException(var7, var19);
            }

            skipAnnotation(var0, false);
            return null;
        } catch (TypeNotPresentException var20) {
            if (var3) {
                throw var20;
            }

            skipAnnotation(var0, false);
            return null;
        }

        if (var4 != null && !contains(var4, var6)) {
            skipAnnotation(var0, false);
            return null;
        } else {
            AnnotationType var8 = null;

            try {
                var8 = AnnotationType.getInstance(var6);
            } catch (IllegalArgumentException var17) {
                skipAnnotation(var0, false);
                return null;
            }

            Map var9 = var8.memberTypes();
            LinkedHashMap var10 = new LinkedHashMap(var8.memberDefaults());
            int var11 = var0.getShort() & '\uffff';

            for(int var12 = 0; var12 < var11; ++var12) {
                int var13 = var0.getShort() & '\uffff';
                String var14 = var1.getUTF8At(var13);
                Class var15 = (Class)var9.get(var14);
                if (var15 == null) {
                    skipMemberValue(var0);
                } else {
                    Object var16 = parseMemberValue(var15, var0, var1, var2);
                    if (var16 instanceof AnnotationTypeMismatchExceptionProxy) {
                        ((AnnotationTypeMismatchExceptionProxy)var16).setMember((Method)var8.members().get(var14));
                    }

                    var10.put(var14, var16);
                }
            }

            return annotationForMap(var6, var10);
        }
    }

cretateAnnotationData()函数：
declaredAnnnotations用来存储所有的注解

class和ClassLoader