003-搭建框架-实现IOC机制

一、实现目标

一种MVC【Model-View-Controller】一种设计模式，进行解耦。

/*
 * 处理客户管理相关请求
*/
@Controller
public class CustomerController {
    @Inject
    private CustomService customService;

    @Action("get:/customer")
    public View index(Param param) {
        List<Customer> customerList = customService.getCustomerList("");
        return new View("customer.jsp").addModel("customerlist", customerList);
    }

    @Action("get:/customer_show")
    public View show(Param param) {
        long id = param.getLong("id");
        Customer customer = customService.getCustomer(id);
        return new View("customer_show.jsp").addModel("customer", customer);
    }

    @Action("get:/customer_create")
    public View create(Param param) {
        return new View("customer_create.jsp");
    }

    @Action("post:/customer_create")
    public Data createSumbit(Param param) {
        Map<String, Object> paramMap = param.getParamMap();
        boolean result = customService.createCustomer(paramMap);
        return new Data(result);
    }

    @Action("get:/customer_edit")
    public View edit(Param param) {
        long id = param.getLong("id");
        Customer customer = customService.getCustomer(id);
        return new View("customer_edit.jsp").addModel("customer", customer);
    }

    @Action("post:/customer_edit")
    public Data editSumbit(Param param) {
        long id = param.getLong("id");
        Map<String, Object> paramMap = param.getParamMap();
        boolean result = customService.updateCustomer(id, paramMap);
        return new Data(result);
    }

    @Action("post:/customer_delete")
    public Data delete(Param param) {
        long id = param.getLong("id");
        boolean result = customService.deleteCustomer(id);
        return new Data(result);
    }
}

注：

　　通过@Controller注解来定义Controller类；通过注解@Inject来定义成员属性；

　　通过@Service注解来定义Service类，通过注解@Action来定义方法；

　　返回View 对象标示jsp页面，Data标示JSon数据

二、代码开发

　　https://github.com/bjlhx15/smart-framework.git 中的chapter3和smart-framework部分

三、知识点

3.1、类加载器

package com.lhx.smart.framework.util;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileFilter;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

public class ClassUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(ClassUtil.class);

    /**
     * 获取类加载器
     *
     * @return
     */
    public static ClassLoader getClassLoader() {
        return Thread.currentThread().getContextClassLoader();
    }

    /**
     * 加载类
     *
     * @param className
     * @param isInitialized
     * @return
     */
    public static Class<?> loadClass(String className, boolean isInitialized) {
        Class<?> cls;
        try {
            cls = Class.forName(className, isInitialized, getClassLoader());
        } catch (ClassNotFoundException e) {
            LOGGER.error("类加载失败", e);
            throw new RuntimeException(e);
        }
        return cls;
    }

    /**
     * 获取制定报名下的所有类
     *
     * @param packageName
     * @return
     */
    public static Set<Class<?>> getClassSet(String packageName) {
        Set<Class<?>> classSet = new HashSet<Class<?>>();
        try {
            Enumeration<URL> urls = getClassLoader().getResources(packageName.replace(".", "/"));
            while (urls.hasMoreElements()) {
                URL url = urls.nextElement();
                if (null != url) {
                    String protocol = url.getProtocol();
                    if (protocol.equals("file")) {
                        String packagePath = url.getPath().replaceAll("%20", " ");
                        addClass(classSet, packagePath, packageName);
                    } else if (protocol.equals("jar")) {
                        JarURLConnection jarURLConnection = (JarURLConnection) url.openConnection();
                        if (jarURLConnection != null) {
                            JarFile jarFile = jarURLConnection.getJarFile();
                            if (jarFile != null) {
                                Enumeration<JarEntry> entries = jarFile.entries();
                                while (entries.hasMoreElements()) {
                                    JarEntry jarEntry = entries.nextElement();
                                    String jarEntryName = jarEntry.getName();
                                    if (jarEntryName.endsWith(".class")) {
                                        String className = jarEntryName.substring(0, jarEntryName.lastIndexOf(".")).replaceAll("/", ".");
                                        doAddClass(classSet, className);
                                    }

                                }
                            }
                        }
                    }
                }
            }
        } catch (Exception e) {
            LOGGER.error("获取classSet 失败", e);
            throw new RuntimeException(e);
        }
        return classSet;
    }

    private static void addClass(Set<Class<?>> classSet, String packagePath, String packageName) {
        File[] files = new File(packagePath).listFiles(new FileFilter() {
            public boolean accept(File file) {
                return (file.isFile() && file.getName().endsWith(".class")) || file.isDirectory();
            }
        });
        for (File file : files) {
            String fileName = file.getName();
            if (file.isFile()) {
                String className = fileName.substring(0, fileName.lastIndexOf("."));
                if (StringUtils.isNotEmpty(packageName)) {
                    className = packageName + "." + className;
                }
                doAddClass(classSet, className);
            } else {
                String subPackagePath = fileName;
                if (StringUtils.isNotEmpty(packagePath)) {
                    subPackagePath = packagePath + "/" + subPackagePath;
                }
                String subPackageName = fileName;
                if (StringUtils.isNotEmpty(packageName)) {
                    subPackageName = packageName + "." + subPackageName;
                }
                addClass(classSet, subPackagePath, subPackageName);
            }
        }
    }

    private static void doAddClass(Set<Class<?>> classSet, String className) {
        Class<?> cls = loadClass(className, false);
        classSet.add(cls);
    }
}

3.2、反射工具类

package com.lhx.smart.framework.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.lang.reflect.Field;
import java.lang.reflect.Method;

/**
 * 反射工具类
 */
public final class ReflectionUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(ReflectionUtil.class);

    /**
     * 创建实例
     *
     * @param cls
     * @return
     */
    public static Object newInstance(Class<?> cls) {
        Object instance;
        try {
            instance = cls.newInstance();
        } catch (Exception e) {
            LOGGER.error("实例化失败", e);
            throw new RuntimeException(e);
        }
        return instance;
    }

    /**
     * 调用方法
     *
     * @param obj
     * @param method
     * @param args
     * @return
     */
    public static Object invokeMethod(Object obj, Method method, Object... args) {
        Object result;
        try {
            method.setAccessible(true);
            result = method.invoke(obj, args);
        } catch (Exception e) {
            LOGGER.error("调用方法失败", e);
            throw new RuntimeException(e);
        }
        return result;
    }

    public static void setFiled(Object obj, Field field, Object value) {
        try {
            field.setAccessible(true);
            field.set(obj, value);
        } catch (Exception e) {
            LOGGER.error("参数设置失败", e);
            throw new RuntimeException(e);
        }
    }
}