List对象转化为JSON数据

import java.lang.reflect.Field;import java.util.ArrayList;import java.util.List;public class FromObjectToJson<T> {    public  String ToJson(List<T> list) {        // 变量        StringBuffer jsonStr = new StringBuffer();        // 前提条件        if (null == list || 0 == list.size()) {            return null;        }        // class对象        Class<?> classType = list.get(0).getClass();        // 得到javabean的名字        String javaBeanClassName = classType.getSimpleName();        jsonStr.append("{\"").append(javaBeanClassName.toLowerCase()).append("s").append("\":[");        // 此JavaBean中所声明的所有字段        Field[] fields = classType.getDeclaredFields();        for (int i = 0; i < list.size(); i++) {            jsonStr.append("{");            for (Field field : fields) {                // 得到字段名                String fieldName = field.getName();                field.setAccessible(true);                // 得到指定对象上此 Field 表示的字段的值                Object fieldValue;                try {                    fieldValue = field.get(list.get(i));                    jsonStr.append("\"").append(fieldName.toLowerCase()).append("\":").append("\"").append(fieldValue)                            .append("\"").append(",");                } catch (IllegalArgumentException e) {                    e.printStackTrace();                } catch (IllegalAccessException e) {                    e.printStackTrace();                }            }            jsonStr.deleteCharAt(jsonStr.length() - 1);            jsonStr.append("},");        }        jsonStr.deleteCharAt(jsonStr.length() - 1);        jsonStr.append("]}");        return jsonStr.toString();    }    public static void main(String[] args) {        List<UserModel> list = new ArrayList<UserModel>();        UserModel  userModel1 = new UserModel(1, "张三", "男");        UserModel  userModel2 = new UserModel(2, "李四", "男");        UserModel  userModel3 = new UserModel(3, "美女", "女");        list.add(userModel1);        list.add(userModel2);        list.add(userModel3);        String json_string = new FromObjectToJson<UserModel>().ToJson(list);        System.out.println("\n json数据:" + json_string);    }}

1.效果图如下显示

 json数据:{"usermodels":[{"id":"1","name":"张三","sex":"男"},{"id":"2","name":"李四","sex":"男"},{"id":"3","name":"美女","sex":"女"}]}