如何獲取實體類中的屬性和屬性值

今天和app端對接口的時候，他希望我將MySQL查到的信息返回給他們，即使是null信息。

我百度了很久發現 是實體類中的屬性和屬性值的問題 。

下面使用反射機制獲取類的屬性名和屬性值。

實體類

public class ResumePerCompanyWantVO{

	private BigDecimal  startWage; 
	private BigDecimal  endWage; 
	private String  workTime; 
	private int  scale; 
	private String scaleName; 
	private int  peopleSize; 
	private String peopleSizeName;
	private int  companyType; 
	private String  companyTypeName; 
	private String  industryIds; 
	private String  industryNames; 

//請自行加上get set 方法

 展示結果 ：

{
  "msg": "操作成功",
  "result": {
    "ResumePerCompanyWantVO": {
      "industryNames": "",
      "industryIds": "",
      "companyType": 0,
      "peopleSizeName": "",
      "endWage": "",
      "scale": 0,
      "scaleName": "",
      "startWage": "",
      "workTime": "",
      "peopleSize": 0,
      "companyTypeName": ""
    }
  "code": 1000
}

 獲取屬性和屬性值的方法

    /**
     * 獲取屬性名數組
     * */
    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++){
//            System.out.println(fields[i].getType());
            fieldNames[i]=fields[i].getName();
        }
        return fieldNames;
    }

    /* 根據屬性名獲取屬性值
     * */
    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) {

            return null;
        }
    }

 調用

           String[] fieldNames = getFiledName(companyWantByUserId);
            
            Map<String,Object>  companyWantMap =new HashMap<>();
          
            for(int j=0 ; j<fieldNames.length ; j++){     //遍歷所有屬性
                String name = fieldNames[j];    //獲取屬性的名字
                Object value = getFieldValueByName(name,companyWantByUserId);
                if (value == null){
                    value = "";
                }
                companyWantMap.put(name,value);
            }