com.github.gkutiel.flip.web.MethodInvokerFinder Maven / Gradle / Ivy

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package com.github.gkutiel.flip.web;

import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Method;
import java.util.Map;
import java.util.Map.Entry;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.github.gkutiel.flip.utils.Utils;

interface MethodInvokerFinder {
	static class CatchAllFinder implements MethodInvokerFinder {

		private final Map> catchAll;

		CatchAllFinder(final Map> catchAll) {
			this.catchAll = catchAll;
		}

		private String[] argsFromPath(final String path, final String prefix) {
			if (path.length() == 1) return new String[0];
			return path.substring(prefix.length() + 1).split("/");
		}

		@Override
		public MethodInvoker find(final HttpServletRequest req, final HttpServletResponse res) {
			final String path = req.getPathInfo();
			final Entry> catchAll = findCatchAll(path);
			if (catchAll == null) return null;
			final String prefix = catchAll.getKey();
			final String[] args = argsFromPath(path, prefix);
			final Class clazz = catchAll.getValue();
			final Method method = findMethod(clazz, args);
			if (method == null) return null;
			return new MethodInvokerCatchAll(clazz, method, args);
		}

		private Entry> findCatchAll(final String path) {
			for (final Entry> catchAll : this.catchAll.entrySet()) {
				final String prefix = catchAll.getKey();
				if (path.startsWith(prefix)) return catchAll;
			}
			return null;
		}

		private Method findMethod(final Class clazz, final String[] args) {
			final Method[] methods = clazz.getDeclaredMethods();
			AccessibleObject.setAccessible(methods, true);
			for (final Method method : methods)
				if (method.getParameterTypes().length == args.length) return method;
			return null;
		}

	}

	static class DefaultFinder implements MethodInvokerFinder {

		@Override
		public MethodInvoker find(final HttpServletRequest req, final HttpServletResponse res) {
			try {
				final String[] args = req.getPathInfo().substring(1).split("/");
				if (args.length < 2) return null;
				final Class clazz = Class.forName("web." + args[0]);
				final Method method = Utils.Reflection.findFirstMethod(clazz, args[1]);
				if (method == null) return null;
				return new MethodInvokerDefault(clazz, method);
			} catch (final ClassNotFoundException e) {
				// TODO (gilad) log
				return null;
			}
		}

	}

	MethodInvoker find(final HttpServletRequest req, final HttpServletResponse res);
}