解释主要在代码里，在这里就不多废话了，直接上代码：

package onlyfun.caterpillar;public class Student {private String name;private int score; public Student() {name = "N/A"; } public Student(String name, int score) { this.name = name; this.score = score; } public void setName(String name) {this.name = name;}public void setScore(int score) {this.score = score;}public String getName() { return name; } public int getScore() { return score; } public String toString() {return name + ":" + score;}
}

package onlyfun.caterpillar;import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Map;public class CommandUtil {// 给定Map对象及要产生的Bean类名称// 可以取回已经设定完成的对象public static Object getCommand(Map requestMap, String commandClass) throws Exception {Class c = Class.forName(commandClass);Object o = c.newInstance();return updateCommand(requestMap, o);}// 使用reflection自动找出要更新的属性public static Object updateCommand(Map requestMap, Object command) throws Exception {Method[] methods = command.getClass().getDeclaredMethods();for(int i = 0; i < methods.length; i++) {// 略过private、protected成员// 且找出必须是set开头的方法名称if(!Modifier.isPrivate(methods[i].getModifiers()) &&!Modifier.isProtected(methods[i].getModifiers()) &&  methods[i].getName().startsWith("set")) {// 取得不包括set的名称String name = methods[i].getName().substring(3).toLowerCase();// 如果setter名称与键值相同// 呼叫对应的setter并设定值if(requestMap.containsKey(name)) {String param = (String) requestMap.get(name);Object[] values = findOutParamValues(param, methods[i]);methods[i].invoke(command, values);}}}return command;  }// 转换为对应类型的值private static Object[] findOutParamValues(String param, Method method) {Class[] params = method.getParameterTypes();Object[] objs = new Object[params.length];for(int i = 0; i < params.length; i++) {if(params[i] == String.class) {objs[i] = param;}else if(params[i] == Short.TYPE) {short number = Short.parseShort(param);objs[i] = new Short(number);}else if(params[i] == Integer.TYPE) {int number = Integer.parseInt(param);objs[i] = new Integer(number);}else if(params[i] == Long.TYPE) {long number = Long.parseLong(param);objs[i] = new Long(number);}else if(params[i] == Float.TYPE) {float number = Float.parseFloat(param);objs[i] = new Float(number);}else if(params[i] == Double.TYPE) {double number = Double.parseDouble(param);objs[i] = new Double(number);}else if(params[i] == Boolean.TYPE) {boolean bool = Boolean.parseBoolean(param);objs[i] = new Boolean(bool);}}    return objs;}
}

package onlyfun.caterpillar;import java.util.*;public class CommandUtilDemo {public static void main(String[] args) throws Exception {Map<String, String> request = new HashMap<String, String>();request.put("name", "wenhaozhong");request.put("score", "90");
//        Object obj = CommandUtil.getCommand(request, args[0]);Object obj = CommandUtil.getCommand(request, "onlyfun.caterpillar.Student");System.out.println(obj);}
}

输出结果为：