package com.coderising.litestruts;
import java.io.File;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
public class Struts {
private final static Map<String, Action> actions = new HashMap<String, Action>();
@SuppressWarnings("rawtypes")
public static View runAction(String actionName, Map<String,String> parameters) throws Exception {
/*
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。
*/
//读取xml,把xml信息放到actions
readStrutsXML();
Action action = actions.get(actionName);
View view = new View();
if(action != null){
Class clazz = Class.forName(action.getClassName());
Object obj = clazz.newInstance();
//根据parameters调用set方法
initClass(clazz, obj, action, parameters);
//调用execute方法
String result = execute(clazz, obj);
//调用所有get方法
Map resultParameters = getResultParameters(clazz, obj);
view.setJsp(action.getResults().get(result));
view.setParameters(resultParameters);
}
return view;
}
@SuppressWarnings("rawtypes")
private static Map getResultParameters(Class clazz, Object obj) throws Exception {
Map<String, String> resultParameters = new HashMap<String, String>();
Method[] methods = clazz.getMethods();
String methodName;
String propName;
String propValue;
for(Method method : methods){
methodName = method.getName();
if(methodName.startsWith("get") && !"getClass".equals(methodName)){
propName = firstLetterLowerCase(methodName.substring(3, methodName.length()));
propValue = (String) method.invoke(obj);
resultParameters.put(propName, propValue);
}
}
return resultParameters;
}
@SuppressWarnings({ "unchecked", "rawtypes" })
private static String execute(Class clazz, Object obj) throws Exception{
Method method = clazz.getMethod("execute");
return (String)method.invoke(obj);
}
@SuppressWarnings({ "unchecked", "rawtypes" })
private static void initClass(Class clazz, Object obj, Action action, Map<String, String> parameters) throws Exception {
String setMethodName;
Method method = null;
for (String parameter : parameters.keySet()) {
setMethodName = "set" + firstLetterUpperCase(parameter);
method = clazz.getMethod(setMethodName, String.class);
method.invoke(obj, parameters.get(parameter));
}
}
private static String firstLetterLowerCase(String string){
char[] cs = string.toCharArray();
cs[0] += 32;
return String.valueOf(cs);
}
private static String firstLetterUpperCase(String string){
char[] cs = string.toCharArray();
cs[0] -= 32;
return String.valueOf(cs);
}
@SuppressWarnings("unchecked")
private static void readStrutsXML() {
SAXReader saxReader = new SAXReader();
Document document;
try {
document = saxReader.read(new File("src/com/coderising/litestruts/struts.xml"));
} catch (DocumentException e) {
System.out.println("error:file not found");
return ;
}
Element root = document.getRootElement();
Iterator<Element> actionItr = root.elementIterator();
Element action;
Action act;
Iterator<Element> resultItr;
Element result;
Map<String, String> results;
while(actionItr.hasNext()){
action = actionItr.next();
resultItr = action.elementIterator();
results = new HashMap<String, String>();
while(resultItr.hasNext()){
result = resultItr.next();
results.put(result.attributeValue("name"), result.getStringValue());
}
act = new Action();
act.setName(action.attributeValue("name"));
act.setClassName(action.attributeValue("class"));
act.setResults(results);
actions.put(act.getName(), act);
}
}
static class Action {
private String name;
private String className;
private Map<String, String> results = new HashMap<>();
public Map<String, String> getResults() {
return results;
}
public void setResults(Map<String, String> results) {
this.results = results;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getClassName() {
return className;
}
public void setClassName(String className) {
this.className = className;
}
}
}