package com.coderising.litestruts;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
public class Struts {
public static View runAction(String actionName, Map<String,String> parameters) {
/*
0. 读取配置文件struts.xml
1. 根据actionName找到相对应的class , 例如LoginAction, 通过反射实例化(创建对象)
据parameters中的数据,调用对象的setter方法, 例如parameters中的数据是
("name"="test" , "password"="1234") ,
那就应该调用 setName和setPassword方法
2. 通过反射调用对象的exectue 方法, 并获得返回值,例如"success"
3. 通过反射找到对象的所有getter方法(例如 getMessage),
通过反射来调用, 把值和属性形成一个HashMap , 例如 {"message": "登录成功"} ,
放到View对象的parameters
4. 根据struts.xml中的 <result> 配置,以及execute的返回值, 确定哪一个jsp,
放到View对象的jsp字段中。
*/
View view = null;
SAXReader reader = new SAXReader();
InputStream resourceAsStream = Struts.class.getResourceAsStream("struts.xml");
try {
Document document = reader.read(resourceAsStream);
Element rootElement = document.getRootElement();
Element element = findElement(rootElement, actionName);
if(element == null){
throw new RuntimeException("指定节点不存在");
}
//子节点数据信息
Map<String, String> elementData = getElementData(element);
Class<?> forName = Class.forName(element.attribute("class").getValue());
Object classInstance = forName.newInstance();
PropertyDescriptor[] propertyDescriptors = Introspector.getBeanInfo(forName).getPropertyDescriptors();
for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {
String name = propertyDescriptor.getName();
Method readMethod = propertyDescriptor.getWriteMethod();
if(parameters != null && parameters.size() > 0 && parameters.containsKey(name) && readMethod != null){
readMethod.setAccessible(true);
readMethod.invoke(classInstance, parameters.get(name));
}
}
Method method = forName.getDeclaredMethod("execute");
method.setAccessible(true);
Object o = method.invoke(classInstance);
Map<String,Object> viewMap = new HashMap<String, Object>();
for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {
String name = propertyDescriptor.getName();
Method readMethod = propertyDescriptor.getReadMethod();
if(readMethod != null && !"class".equals(name)){
viewMap.put(name, readMethod.invoke(classInstance));
}
}
view = new View();
view.setParameters(viewMap);
if(elementData != null && elementData.size() > 0 && elementData.containsKey(o)){
view.setJsp(elementData.get(o));
}else{
view.setJsp(null);
}
} catch (DocumentException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (SecurityException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IntrospectionException e) {
e.printStackTrace();
}
return view;
}
/**
* 根据名称获取指定节点
* @param rootElement 根节点
* @param actionName action名称
* @return
*/
private static Element findElement(Element rootElement,String actionName){
@SuppressWarnings("unchecked")
List<Element> elements = rootElement.elements("action");
for (Element element : elements) {
Attribute name = element.attribute("name");
if(name == null){
return null;
}
String value = name.getValue();
if(value == null || !value.equals(actionName)){
continue;
}
Attribute actionClass = element.attribute("class");
if(actionClass == null || actionClass.getValue() == null){
return null;
}
return element;
}
return null;
}
/**
* 获取action下的result节点信息
* @param element action节点
* @return
*/
private static Map<String, String> getElementData(Element element){
Map<String, String> map = null;
@SuppressWarnings("unchecked")
List<Element> elements = element.elements("result");
for (Element elementSub : elements) {
if(map == null){
map = new HashMap<String, String>();
}
Attribute attribute = elementSub.attribute("name");
if(attribute!=null){
map.put(attribute.getValue(), elementSub.getTextTrim());
}
}
return map;
}
}