java 反射给成员变量设值

- 日理万妓 2022-08-02 11:50 176阅读 0赞

1，已知一个类全路径名称，即包名，类名，该类有成员变量，public属性，没有get和set方法。

2，已知另一个Bean类属性和1中的成员变量和类型都一样，将bean转换成json字符串，

3 ，遍历json，key,和1类成员变量相同，则给1中的成员设值。

代码：1 类。

public class NoPerson1 implements Copyable, Serializable\{  
   
/\* \*//\*\*  
  \* serialVersionUID  
  \*//\*  
 private static final long serialVersionUID = -2445027108030048781L;\*/

public String name = "";  
   
 public String adress = "";  
   
 /\* (non-Javadoc)  
  \* @see java.lang.Object\#toString()  
  \*/  
 @Override  
 public String toString() \{  
  return "NoPerson \[name=" + name + ", adress=" + adress + ", age=" + age  
    + ", job=" + job + ", country=" + country + "\]";  
 \}

public int age = 0;  
   
 public String job = "";  
   
 public String country = "";

/\* (non-Javadoc)  
  \* @see com.rti.dds.infrastructure.Copyable\#copy\_from(java.lang.Object)  
  \*/  
 @Override  
 public Object copy\_from(Object arg0) \{  
  return null;  
 \}

2，类

/\*\*  
 \* @author Administrator  
 \*  
 \*/  
public class Person1 \{  
   
 private String name = "";  
   
 private String adress = "";  
   
 private int age = 0;  
   
 private String job = "";  
   
 private String country = "";  
   
 private String ss = "";

/\*\*  
  \* @return the name  
  \*/  
 public String getName() \{  
  return name;  
 \}

/\*\*  
  \* @param name the name to set  
  \*/  
 public void setName(String name) \{  
  this.name = name;  
 \}

/\*\*  
  \* @return the adress  
  \*/  
 public String getAdress() \{  
  return adress;  
 \}

/\*\*  
  \* @param adress the adress to set  
  \*/  
 public void setAdress(String adress) \{  
  this.adress = adress;  
 \}

/\*\*  
  \* @return the age  
  \*/  
 public int getAge() \{  
  return age;  
 \}

/\*\*  
  \* @param age the age to set  
  \*/  
 public void setAge(int age) \{  
  this.age = age;  
 \}

/\*\*  
  \* @return the job  
  \*/  
 public String getJob() \{  
  return job;  
 \}

/\*\*  
  \* @param job the job to set  
  \*/  
 public void setJob(String job) \{  
  this.job = job;  
 \}

/\*\*  
  \* @return the country  
  \*/  
 public String getCountry() \{  
  return country;  
 \}

/\*\*  
  \* @param country the country to set  
  \*/  
 public void setCountry(String country) \{  
  this.country = country;  
 \}

/\*\*  
  \* @return the ss  
  \*/  
 public String getSs() \{  
  return ss;  
 \}

/\*\*  
  \* @param ss the ss to set  
  \*/  
 public void setSs(String ss) \{  
  this.ss = ss;  
 \}

/\* (non-Javadoc)  
  \* @see java.lang.Object\#toString()  
  \*/  
 @Override  
 public String toString() \{  
  return "Person1 \[name=" + name + ", adress=" + adress + ", age=" + age  
    + ", job=" + job + ", country=" + country + ", ss=" + ss + "\]";  
 \}

3 实现方法：

/\*\*  
 \*  
 \*/  
package com.neusoft.reflect;

import java.lang.reflect.Field;  
import java.util.Iterator;  
import java.util.Set;  
import java.util.Map.Entry;

import com.alibaba.fastjson.JSON;  
import com.alibaba.fastjson.JSONObject;  
import com.neusoft.bean.Person;  
import com.neusoft.beans.Person1;

/\*\*  
 \* @author Administrator  
 \*  
 \*/  
public class Main3 \{

/\*\*  
  \* @param args  
  \* 作者:Administrator  
  \* 日期:2015年7月18日下午7:32:07  
  \* 返回类型:void  
  \*/  
 public static void main(String\[\] args) \{  
  String className = "com.neusoft.beans.NoPerson1";  
  Person1 p = new Person1();  
  p.setAdress("Shanghai");  
  p.setAge(32);  
  p.setCountry("china");  
  p.setJob("soft");  
  p.setName("liushw");  
  p.setSs("hahaahah");  
  System.out.println(p.toString());  
  String jsonStr = JSON.toJSONString(p);  
  System.out.println("jsonStr=:"+jsonStr);  
  // json 便利  
  JSONObject jsonObj = JSONObject.parseObject(jsonStr);  
  Set<Entry<String, Object>> it = jsonObj.entrySet();  
  Class c = null;  
  try \{  
   c = Class.forName(className);  
  \} catch (ClassNotFoundException e) \{  
   e.printStackTrace();  
  \}  
    
  Object o = null;  
  try \{  
   o = c.newInstance();  
  \} catch (InstantiationException e1) \{  
   e1.printStackTrace();  
  \} catch (IllegalAccessException e1) \{  
   e1.printStackTrace();  
  \}  
    
  Field\[\] fs = c.getDeclaredFields();  
  for (Iterator iterator = it.iterator(); iterator.hasNext();) \{  
   Entry<String, Object> entry = (Entry<String, Object>) iterator.next();  
   for (int i = 0; i < fs.length; i++) \{  
    Field f = fs\[i\];  
    f.setAccessible(true); // 设置些属性是可以访问的  
    Object val;  
    try \{  
     val = f.get(o);  
     System.out.println("name:" + f.getName() + "\\t value = " + val);  
     // 得到此属性的值  
     String type = f.getType().toString();// 得到此属性的类型  
     System.out.println("\[数据类型:"+type);  
     if(f.getName().equalsIgnoreCase(entry.getKey()) )\{  
      f.set(o, entry.getValue()); // 给属性设值  
     \}  
    \} catch (IllegalArgumentException e) \{  
     e.printStackTrace();  
    \} catch (IllegalAccessException e) \{  
     e.printStackTrace();  
    \}  
   \}  
  \}  
  System.out.println(o.toString());  
 \}

测试结果：

Person1 \[name=liushw, adress=Shanghai, age=32, job=soft, country=china, ss=hahaahah\]  
jsonStr=:\{"adress":"Shanghai","age":32,"country":"china","job":"soft","name":"liushw","ss":"hahaahah"\}  
name:name  value =  
\[数据类型:class java.lang.String  
name:adress  value =  
\[数据类型:class java.lang.String  
name:age  value = 0  
\[数据类型:int  
name:job  value =  
\[数据类型:class java.lang.String  
name:country  value =  
\[数据类型:class java.lang.String  
name:name  value =  
\[数据类型:class java.lang.String  
name:adress  value =  
\[数据类型:class java.lang.String  
name:age  value = 0  
\[数据类型:int  
name:job  value =  
\[数据类型:class java.lang.String  
name:country  value =  
\[数据类型:class java.lang.String  
name:name  value =  
\[数据类型:class java.lang.String  
name:adress  value =  
\[数据类型:class java.lang.String  
name:age  value = 0  
\[数据类型:int  
name:job  value =  
\[数据类型:class java.lang.String  
name:country  value = china  
\[数据类型:class java.lang.String  
name:name  value = liushw  
\[数据类型:class java.lang.String  
name:adress  value =  
\[数据类型:class java.lang.String  
name:age  value = 0  
\[数据类型:int  
name:job  value =  
\[数据类型:class java.lang.String  
name:country  value = china  
\[数据类型:class java.lang.String  
name:name  value = liushw  
\[数据类型:class java.lang.String  
name:adress  value = Shanghai  
\[数据类型:class java.lang.String  
name:age  value = 0  
\[数据类型:int  
name:job  value =  
\[数据类型:class java.lang.String  
name:country  value = china  
\[数据类型:class java.lang.String  
name:name  value = liushw  
\[数据类型:class java.lang.String  
name:adress  value = Shanghai  
\[数据类型:class java.lang.String  
name:age  value = 0  
\[数据类型:int  
name:job  value = soft  
\[数据类型:class java.lang.String  
name:country  value = china  
\[数据类型:class java.lang.String  
NoPerson \[name=liushw, adress=Shanghai, age=32, job=soft, country=china\]