package com.ObjectToJson;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Iterator;
public 
class ObjectToJson {
	
	
	public  static String ObjListToJson(ArrayList<?> list){
		StringBuilder build=new StringBuilder();
		//迭代器
		Iterator<?> iterator=list.iterator();
		build.append("[");
		String separate="";
		while(iterator.
hasNext()){
			build.append(separate);
			//object转json字符串
			String str=ObjToJson(iterator.next());
			build.append(str);
			separate=",";
		}
		build.append("]");
		return build.toString();
	}
	
	@SuppressWarnings("unchecked")
	public  static String ObjToJson(Object obj){
		StringBuilder build=new StringBuilder();
		build.append("{");
		@SuppressWarnings("rawtypes")
		Class cla=null;
		try {
			//反射加载类
			cla=Class.forName(obj.getClass().getName());
		} catch (ClassNotFoundException e) {
			System.out.println(obj.getClass().toString().concat(" 未找到这个类"));
			e.printStackTrace();
			return null;
		}
		
		StringBuffer methodname=new StringBuffer();
		//获取java类的变量
		Field[] fields=cla.getDeclaredFields();
		String separate="";
		for(Field temp:fields){
			build.append(separate);
			build.append("\"");
			build.append(temp.getName());
			build.append("\":");
			
			methodname.append("get");
			methodname.append(temp.getName().substring(0,1).toUpperCase());
			methodname.append(temp.getName().substring(1));
			
			build.append("\"");
			Method method=null;
			try {
				//获取java的get方法
				method=cla.getMethod(methodname.toString());
			} catch (NoSuchMethodException | SecurityException e) {
				methodname.setLength(0);
				e.printStackTrace();
			}
			
			try {
				//执行get方法,获取变量参数的直。
				build.append(method.invoke(obj));
			} catch (IllegalAccessException e) {
				e.printStackTrace();
			} catch (IllegalArgumentException e) {
				e.printStackTrace();
			} catch (InvocationTargetException e) {
				e.printStackTrace();
			}
			build.append("\"");
			methodname.setLength(0);
			separate=",";
		}
		
		build.append("}");
		return build.toString();
	}
}