com.us.reflect.ClassFinder.java Source code

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Here is the source code for com.us.reflect.ClassFinder.java

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/*
 * @(#)ClassFinder.java 2011-11-17
 * ?us??  2008-2011, Inc. All rights reserved.
 * s.server. Use is subject to license terms.
 */

package com.us.reflect;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.LinkedList;
import java.util.List;

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

import org.apache.commons.beanutils.BeanUtils;
import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.ActionProxy;
import com.us.dao.DaoHelper;
import com.us.util.ArrayHelper;

/**
 * ?
 * 
 * @author <a href="mailto:monlyu.hong@gmail.com">monlyu</a>
 * @version --0.0.0--, 2011-11-17
 * @since JDK6.0
 */
public class ClassFinder {

    /**
     *  before
     * @param invocation
     */
    public static void beforeAction(ActionInvocation invc, String actionPath) throws Exception {
        ActionInvocation invocation = (ActionInvocation) invc;
        final ActionProxy proxy = invocation.getProxy();
        Class<?> classFromPath = findClass(actionPath);// ?Class
        Class<?> targetClass = classFromPath == null ? proxy.getAction().getClass() : classFromPath;
        String methodName = findMethodName(actionPath);// ??? checkExist(sessionKey)
        String[] paramers = findParameters(actionPath);
        Class<?>[] paramersType = findParameterTypes(targetClass, paramers);
        Method method = targetClass.getDeclaredMethod(methodName, paramersType);
        Object runner = targetClass.newInstance();
        Field[] allFiled = targetClass.getDeclaredFields();
        for (Field field : allFiled) {
            String beanName = field.getName();
            Object bean = DaoHelper.getBeanById(beanName);
            if (bean != null) {
                BeanUtils.setProperty(runner, beanName, bean);
            }
        }
        method.invoke(runner, getRuntimeArgs(invocation, paramers));
    }

    private static Object[] getRuntimeArgs(ActionInvocation invocation, String[] paramers) {
        List<Object> runtime = new LinkedList<Object>();
        HttpServletRequest request = ServletActionContext.getRequest();// HttpServletRequest
        for (String param : paramers) {
            char index0 = param.charAt(0);
            String parname = param.substring(1);
            if (index0 == '#') { // Session ??
                runtime.add(request.getSession().getAttribute(parname));
            } else if (index0 == '$') {
                runtime.add(request.getAttribute(parname));
            } else if (index0 == '@' && parname.equals("request")) {
                runtime.add(request);
            } else if (index0 == '@' && parname.equals("response")) {
                runtime.add(ServletActionContext.getResponse());
            } else {
                runtime.add(DaoHelper.getBeanById(param));
            }
        }
        return runtime.toArray(new Object[] {});
    }

    /**
     *  ??
     * 
     * @param path 
     * @return 
     * @throws ClassNotFoundException
     */
    private static Class<?> findClass(String path) throws ClassNotFoundException {
        int methodIndex = path.indexOf("(");
        if (methodIndex != -1) {
            int dot = path.lastIndexOf(".", methodIndex);
            if (dot == -1)
                return null;
            path = path.substring(0, dot);
        }
        return Class.forName(path);
    }

    /**
     * ?? <br/>
     * com.us.interfaces.MethodInvoke.showMessage(name)  showMessage
     * 
     * @param path 
     * @return ??
     */
    private static String findMethodName(String path) {
        int methodIndex = path.indexOf("(");
        if (methodIndex == -1)
            throw new IllegalArgumentException("Not Found Mthod Flag \"(\"");
        int lastDot = path.lastIndexOf(".", methodIndex);
        return path.substring(lastDot + 1, methodIndex);
    }

    /**
     * ??
     * 
     * @param path 
     * @return
     */
    private static String[] findParameters(String path) {
        int methodStart = path.indexOf("(");
        if (methodStart == -1) {
            return ArrayHelper.make();
        }
        int methodEnd = path.indexOf(")");
        String list = path.substring(methodStart + 1, methodEnd);
        if (list.trim().equals("")) {
            return ArrayHelper.make();
        }
        List<String> plist = new LinkedList<String>();
        for (String param : list.split(",")) {
            if (param.trim().equals(""))
                throw new IllegalArgumentException("Parameters error");
            plist.add(param.trim());
        }
        return plist.toArray(new String[] {});
    }

    /**
     * ?
     * 
     * @param container 
     * @param parnames ?
     * @return
     * @throws SecurityException
     * @throws NoSuchFieldException
     */
    private static Class<?>[] findParameterTypes(Class<?> container, String[] parnames)
            throws SecurityException, NoSuchFieldException {
        List<Class<?>> parames = new LinkedList<Class<?>>();
        for (String param : parnames) {
            char index0 = param.charAt(0);
            String filed = param.substring(1);
            if (index0 == '#') {
                parames.add(Object.class);
            } else if (index0 == '@' && filed.equals("request")) {
                parames.add(HttpServletRequest.class);
            } else if (index0 == '@' && filed.equals("response")) {
                parames.add(HttpServletResponse.class);
            } else if (index0 == '$') {
                parames.add(container.getDeclaredField(filed).getType());
            } else {
                parames.add(container.getDeclaredField(param).getType());
            }
        }
        return parames.toArray(new Class<?>[] {});
    }

    public static void main(String[] args) {
        // System.out.println(StringUtil.join(",", findParameters("checkExist(sessionKey)")));
    }
}