JSON工具类，对象转JSON

Bertha 。 2022-05-24 11:40 250阅读 0赞

基于每次都要写类似这样：

JSONArray arr = new JSONArray();
    Iterator<Campus> it = list.iterator();
    while (it.hasNext()) {
    	Campus campus = (Campus) it.next();
    	JSONObject json = new JSONObject();
    	json.put("id", campus.getId());
    	json.put("name", campus.getName());
    	json.put("address", campus.getAddress());
    	json.put("remark", campus.getRemark());
    	arr.add(json);
    	}

特此写个工具类：

结果：

[{"java.lang.Integer":1},{"java.lang.Integer":2},{"java.lang.Integer":3}]
    [{"id":3,"title":"斗破苍穹","price":3.3,"publishDate":1527312754008},{"id":3,"title":"斗破苍穹","price":3.3,"publishDate":1527312754008},{"id":3,"title":"斗破苍穹","price":3.3,"publishDate":1527312754008}]

代码：

public class ObjToJson {
    	public static void main(String[] args) {
    		List<Integer> list = new ArrayList<>();
    		list.add(1);
    		list.add(2);
    		list.add(3);
    		
    		List<Book> list2 = new ArrayList<>();
    		Book b = new Book();
    		b.setId(1);
    		list2.add(b);
    		b.setId(2);
    		b.setPrice(2.2);
    		list2.add(b);
    		b.setId(3);
    		b.setPrice(3.3);
    		b.setPublishDate(new Date());
    		b.setTitle("斗破苍穹");
    		list2.add(b);
    		
    		JSONArray arr = JSONPut(list);
    		System.out.println(arr);
    		JSONArray arr2 = JSONPut(list2);
    		System.out.println(arr2);
    	}
    	
    	public static JSONArray JSONPut(List<?> list){
    		JSONArray arr = new JSONArray();
    		for (Iterator<?> iterator = list.iterator(); iterator.hasNext();) {
    			Object object = (Object) iterator.next();
    			//org.json
    			//arr.put(JSONPut(object));
    			arr.add(JSONPut(object));
    		}
    		return arr;
    	}
    	
    	public static JSONObject JSONPut(Object obj){
    		JSONObject json = new JSONObject();
    		String[] values = getFiledName(obj);
    		//基本数据类型
    		if("java.lang".equals(obj.getClass().getName().substring(0,9))){
    			json.put(obj.getClass().getName(),obj);
    			return json;
    		}
    		for (int i = 0; i < values.length; i++) {
    			json.put(values[i], getFieldValueByName(values[i], obj));
    		}
    		return json;
    	}
    	
    	/** 
    	 * 根据属性名获取属性值 
    	 * */  
    	   private static Object getFieldValueByName(String fieldName, Object o) {  
    	       try {    
    	           String firstLetter = fieldName.substring(0, 1).toUpperCase();    
    	           String getter = "get" + firstLetter + fieldName.substring(1);    
    	           Method method = o.getClass().getMethod(getter, new Class[] {});    
    	           Object value = method.invoke(o, new Object[] {});    
    	           return value;    
    	       } catch (Exception e) {    
    	           e.getMessage();    
    	           return null;    
    	       }    
    	   }   
    	     
    	   /** 
    	    * 获取属性名数组 
    	    * */  
    	   private static String[] getFiledName(Object o){  
    	    Field[] fields=o.getClass().getDeclaredFields();  
    	        String[] fieldNames=new String[fields.length];  
    	    for(int i=0;i<fields.length;i++){  
    	        fieldNames[i]=fields[i].getName();  
    	    }  
    	    return fieldNames;  
    	   }
    }

用的是fastjson;

测试的book类：

public class Book implements Serializable{
        /**
    	 * 
    	 */
    	private static final long serialVersionUID = 1L;
    	/**
         * 编号
         */
        private int id;
        /**
         * 书名
         */
        private String title;
        /**
         * 价格
         */
        private double price;
        /**
         * 出版日期
         */
        private Date publishDate;
    
        public Book(int id, String title, double price, Date publishDate) {
            this.id = id;
            this.title = title;
            this.price = price;
            this.publishDate = publishDate;
        }
        
        public Book() {
        }
    
        public int getId() {
            return id;
        }
    
        public void setId(int id) {
            this.id = id;
        }
    
        public String getTitle() {
            return title;
        }
    
        public void setTitle(String title) {
            this.title = title;
        }
    
        public double getPrice() {
            return price;
        }
    
        public void setPrice(double price) {
            this.price = price;
        }
    
        public Date getPublishDate() {
            return publishDate;
        }
    
        public void setPublishDate(Date publishDate) {
            this.publishDate = publishDate;
        }
    @Override
    public String toString() {
    return this.getTitle()+"---"+this.getId()+"----"+this.getPrice()+"--------";
    }
    }