}
// 完全没有Adaptive方法，则不需要生成Adaptive类
if(! hasAdaptiveAnnotation)
throw new IllegalStateException("No adaptive method on extension " + type.getName() + ", refuse to create the adaptive class!");
ClassGenerator cg = ClassGenerator.newInstance(classLoader);
cg.setClassName(type.getName() + "$Adpative");
cg.addInterface(type);
cg.addDefaultConstructor();
for (Method method : methods) {
Class<?> rt = method.getReturnType();
Class<?>[] pts = method.getParameterTypes();
Adaptive adaptiveAnnotation = method.getAnnotation(Adaptive.class);
StringBuilder code = new StringBuilder(512);
if (adaptiveAnnotation == null) {
code.append("throw new UnsupportedOperationException(\"method ")
.append(method.toString()).append(" of interface ")
.append(type.getName()).append(" is not adaptive method!\");");
} else {
int configTypeIndex = -1;
for (int i = 0; i < pts.length; ++i) {
if (pts[i].equals(Config.class)) {
configTypeIndex = i;
break;
}
}
// 有类型为Configs的参数
if (configTypeIndex != -1) {
// Null Point check
String s = String.format("if (arg%d == null) { throw new IllegalArgumentException(\"config == null\"); }",
configTypeIndex);
code.append(s);
s = String.format("%s config = arg%d;", Config.class.getName(), configTypeIndex);
code.append(s);
}
// 参数没有Configs类型
else {
String attribMethod = null;
// 找到参数的Configs属性
LBL_PTS:
for (int i = 0; i < pts.length; ++i) {
Method[] ms = pts[i].getMethods();
for (Method m : ms) {
String name = m.getName();
if ((name.startsWith("get") || name.length() > 3)
&& Modifier.isPublic(m.getModifiers())
&& !Modifier.isStatic(m.getModifiers())
&& m.getParameterTypes().length == 0
&& m.getReturnType() == Config.class) {
configTypeIndex = i;
attribMethod = name;
break LBL_PTS;
}
}
}
if(attribMethod == null) {
throw new IllegalStateException("fail to create adative class for interface " + type.getName()
+ ": not found config parameter or config attribute in parameters of method " + method.getName());
}
// Null point check
String s = String.format("if (arg%d == null) { throw new IllegalArgumentException(\"%s argument == null\"); }",
configTypeIndex, pts[configTypeIndex].getName());
code.append(s);
s = String.format("if (arg%d.%s() == null) { throw new IllegalArgumentException(\"%s argument %s() == null\"); }",
configTypeIndex, attribMethod, pts[configTypeIndex].getName(), attribMethod);
code.append(s);
s = String.format("%s config = arg%d.%s();",Config.class.getName(), configTypeIndex, attribMethod);
code.append(s);
}
String[] value = adaptiveAnnotation.value();
// 没有设置Key，则使用“扩展点接口名的点分隔 作为Key
if(value.length == 0) {
char[] charArray = type.getSimpleName().toCharArray();
StringBuilder sb = new StringBuilder(128);
for (int i = 0; i < charArray.length; i++) {
if(Character.isUpperCase(charArray[i])) {
if(i != 0) {
sb.append(".");
}
sb.append(Character.toLowerCase(charArray[i]));
}
else {
sb.append(charArray[i]);
}
}
value = new String[] {sb.toString()};
}
String defaultExtName = cachedDefaultName;
String getNameCode = null;
for (int i = value.length - 1; i >= 0; --i) {
if(i == value.length - 1) {
if(null != defaultExtName) {
getNameCode = String.format("config.get(\"%s\", \"%s\")", value[i], defaultExtName);
}
else {
getNameCode = String.format("config.get(\"%s\")", value[i]);
}
}
else {
getNameCode = String.format("config.get(\"%s\", %s)", value[i], getNameCode);
}
}
code.append("String extName = ").append(getNameCode).append(";");
// check extName == null?
String s = String.format("if(extName == null) {" +
"throw new IllegalStateException(\"Fail to get extension(%s) name from config(\" + config.toString() + \") use keys(%s)\"); }",
type.getName(), Arrays.toString(value));
code.append(s);
s = String.format("%s extension = (%<s)%s.getExtensionLoader(%s.class).getExtension(extName);",
type.getName(), ExtensionLoader.class.getName(), type.getName());
code.append(s);
// return statement
if (!rt.equals(void.class)) {
code.append("return ");
}
s = String.format("extension.%s(", method.getName());
code.append(s);
for (int i = 0; i < pts.length; i++) {
if (i != 0)
code.append(", ");
code.append("arg").append(i);
}
code.append(");");
}
cg.addMethod(method.getName(), method.getModifiers(), rt, pts,
method.getExceptionTypes(), code.toString());
}
return cg.toClass();
}