Java中通过反射获取泛型实例

package com.jackie.day11;

import java.io.Serializable;
import java.util.Date;

public class Students implements Serializable{

private static final long serialVersionUID = -8655172670979705548L;

private int sid;
private String name;
private String gender;
private Date birthday;
private int score;
private int cid;

public int getSid() {
return sid;
}
public void setSid(int sid) {
this.sid = sid;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public int getScore() {
return score;
}
public void setScore(int score) {
this.score = score;
}
public int getCid() {
return cid;
}
public void setCid(int cid) {
this.cid = cid;
}
@Override
public String toString() {
return "Student [sid=" + sid + ", name=" + name + ", gender=" + gender + ", birthday=" + birthday + ", score="
+ score + ", cid=" + cid + "]";
}

}

package com.jackie.day11;

import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.util.HashMap;
import java.util.Map;

/**
* 通过反射获取泛型实例
* @author Administrator
*
*/
public abstract class Genericity<T> {
/**
* 当前操作的实体的类型信息
*/
@SuppressWarnings("rawtypes")
protected Class clazz;

@SuppressWarnings("unchecked")
public Genericity() {
// 通过反射机制获取子类传递过来的实体类的类型信息
ParameterizedType type = (ParameterizedType) this.getClass().getGenericSuperclass();
clazz = (Class<T>) type.getActualTypeArguments()[0];
}

/**
* 获取指定实例的所有属性名及对应值的Map实例
*
* @param entity
*            实例
* @return 字段名及对应值的Map实例
*/
protected Map<String, Object> getFieldValueMap(T entity) {
// key是属性名，value是对应值
Map<String, Object> fieldValueMap = new HashMap<String, Object>();

// 获取当前加载的实体类中所有属性（字段）
Field[] fields = this.clazz.getDeclaredFields();

for (int i = 0; i < fields.length; i++) {
Field f = fields[i];
String key = f.getName();// 属性名
Object value = null;//属性值
if (! "serialVersionUID".equals(key)) {// 忽略序列化版本ID号
f.setAccessible(true);// 取消Java语言访问检查
try {
value =f.get(entity);
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
fieldValueMap.put(key, value);
}
}
return fieldValueMap;
}
}

package com.jackie.day11;

import java.util.Date;
import java.util.Map;
import java.util.Set;

/**
* 测试：通过反射获取泛型实例
* @author Administrator
*
*/

public class GenericityTest extends Genericity<Students> {

public static void main(String[] args) {

GenericityTest gt = new GenericityTest();

Students ss = new Students();
ss.setBirthday(new Date());
ss.setCid(33);
ss.setGender("男");
ss.setName("张三");
ss.setScore(99);
ss.setSid(4);

Map<String,Object> map = gt.getFieldValueMap(ss);
//遍历这个map对象
Set<Map.Entry<String, Object>> entrySet = map.entrySet();
for (Map.Entry<String, Object> entry : entrySet){
String key = entry.getKey();
Object value = entry.getValue();
System.out.println(key + ">>>>>>>" + value);
}
}
}