package com.example.litestruts;
import com.example.litestruts.dto.Action;
import com.example.litestruts.dto.ActionResult;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Optional;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
public class Struts {
public static View runAction(final 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。
*/
try {
//读取配置文件struts.xml
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document document = db.parse(
"/Users/qilei/idea/coding2017/coding2017/group04/916758663/learn02/src/main/java/com/example/litestruts/struts.xml");
List<Action> actions = parseActions(document);
//1. 根据actionName找到相对应的class
Optional<Action> matchAction = actions.stream()
.filter(action -> action.getName().equals(actionName)).findFirst();
if (matchAction.isPresent()) {
String actionClassName = matchAction.get().getClassName();
Object instance = Class.forName(actionClassName).newInstance();
Class<?> clazz = instance.getClass();
for (Entry<String, String> item : parameters.entrySet()) {
String key = item.getKey();
Field field = clazz.getDeclaredField(key);
field.setAccessible(true);
field.set(instance, item.getValue());
}
Method method = clazz.getDeclaredMethod("execute");
String invokeResult = (String) method.invoke(instance);
Optional<ActionResult> actionResultOptional = matchAction.get().getActionResultList().stream()
.filter(actionResult -> actionResult.getName().equals(invokeResult)).findFirst();
if (actionResultOptional.isPresent()) {
String jsp = actionResultOptional.get().getJsp();
Map<String, String> viewParas = new HashMap<>();
Method[] declaredMethods = clazz.getDeclaredMethods();
for (int i = 0; i < declaredMethods.length; i++) {
Method declaredMethod = declaredMethods[i];
if (declaredMethod.getName().startsWith("get")) {
String value = (String) declaredMethod.invoke(instance);
String key = declaredMethod.getName().substring(3).toLowerCase();
viewParas.put(key,value);
}
}
View view = new View();
view.setJsp(jsp);
view.setParameters(viewParas);
return view;
}
}
System.out.println("Finished");
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
return null;
}
private static List<Action> parseActions(Document document) {
List<Action> actions = new ArrayList<Action>();
NodeList actionList = document.getElementsByTagName("action");
for (int i = 0; i < actionList.getLength(); i++) {
Node item = actionList.item(i);
NamedNodeMap attributes = item.getAttributes();
Action action = new Action();
for (int j = 0; j < attributes.getLength(); j++) {
Node attr = attributes.item(j);
String key = attr.getNodeName();
String value = attr.getNodeValue();
if (key.equals("name")) {
action.setName(value);
} else if (key.equals("class")) {
action.setClassName(value);
}
}
List<ActionResult> actionResultList = new ArrayList<ActionResult>();
NodeList actionResultNodes = item.getChildNodes();
for (int j = 0; j < actionResultNodes.getLength(); j++) {
Node actionResultNode = actionResultNodes.item(j);
if (actionResultNode.getNodeType() == Node.ELEMENT_NODE) {
ActionResult actionResult = new ActionResult();
Element actionResultElement = (Element) actionResultNode;
actionResult.setName(actionResultElement.getAttribute("name"));
actionResult.setJsp(actionResultElement.getFirstChild().getNodeValue());
actionResultList.add(actionResult);
}
}
action.setActionResultList(actionResultList);
actions.add(action);
}
return actions;
}
}