Java 对象转化为Map
## 方式一: 利用FastJson 把对象转化为Map#### 1.项目引入依赖
```java
<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.56</version>
</dependency>
```
#### 2.使用FastJson的ParseObject 方法
```java
//导包
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.TypeReference;
```
```java
/**
*
* @MethodName: getUserInfoDataByUserId
* @Description: 根据useId查询用户信息，封装成mapkey：属性名，value：属性值
* @Param userId 用户userId
* @return
*/
public Map<String, String> getUserInfoDataByUserId(String userId) {
Map<String, String> userMap = new HashMap<String, String>();
BSysUser bSysUser = new BSysUser();
if (StringUtils.isNoneBlank(userId)) {
bSysUser = bSysUserService.selectByKey(userId);
if (null != bSysUser) {
//userMap = new BeanMap(bSysUser);
userMap = JSON.parseObject(JSON.toJSONString(bSysUser), new TypeReference<Map<String, String>>() {
});
}
}
return userMap;
}
```
#### 3.提供接口，供其他模块调用
```java
/**
*
* @MethodName: getAppDataBySceneId
* @Description: 根据userid获取用户信息
* @param userId 用户userId
* @param type 用户对象的属性名,例如 userName,trueName,mobile,userSex,photo
* @return
*/
@ResponseBody
@RequestMapping("/api/user/getUserSingleInfoByUserIdAndAttribute")
public ResponseData getUserSingleInfoByUserIdAndAttribute(String userId, String type) {
ResponseData data = operateFailed("获取数据失败");
String message = "用户信息获取成功";
if (StringUtils.isBlank(userId)) {
data = operateFailed("userId 为空!");
return data;
}
if (StringUtils.isBlank(type)) {
data = operateFailed("type 属性名为空，例如userName,trueName,photo!");
return data;
}
Map<String, String> userMap = getUserInfoDataByUserId(userId);
String value = "";
if (null != userMap && StringUtils.isNoneBlank(type)) {
switch (type) {
case "userName":
value = userMap.get("userName");
break;
case "trueName":
value = userMap.get("trueName");
break;
case "photo":
value = userMap.get("photo");
break;
case "mobile":
value = userMap.get("mobile");
break;
case "isDel":
value = userMap.get("isDel");
break;
case "userSex":
value = userMap.get("userSex");
case "createTime":
value = userMap.get("createTime");
break;
}
}
if (StringUtils.isNoneBlank(value)) {
data = operateSucess(message, value);
}
return data;
}
```
## 方式二: 利用反射进行转换
```java
public class BeanMapUtilByReflect {
/**
* 对象转Map
* @param object
* @return
* @throws IllegalAccessException
*/
public static Map beanToMap(Object object) throws IllegalAccessException {
Map<String, Object> map = new HashMap<String, Object>();
Field[] fields = object.getClass().getDeclaredFields();
for (Field field : fields) {
field.setAccessible(true);
map.put(field.getName(), field.get(object));
}
return map;
}
/**
* map转对象
* @param map
* @param beanClass
* @param <T>
* @return
* @throws Exception
*/
public static <T> T mapToBean(Map map, Class<T> beanClass) throws Exception {
T object = beanClass.newInstance();
Field[] fields = object.getClass().getDeclaredFields();
for (Field field : fields) {
int mod = field.getModifiers();
if (Modifier.isStatic(mod) || Modifier.isFinal(mod)) {
continue;
}
field.setAccessible(true);
if (map.containsKey(field.getName())) {
field.set(object, map.get(field.getName()));
}
}
return object;
}
}
```
## 方式三: 利用工具类进行转换
```java
/**
*
* @MethodName: getUserInfoDataByUserId
* @Description: 根据useId查询用户信息，封装成mapkey：属性名，value：属性值
* @param userId 用户userId
* @return
*/
public Map<String, String> getUserInfoDataByUserId(String userId) {
Map<String, String> userMap = new HashMap<String, String>();
BSysUser bSysUser = new BSysUser();
if (StringUtils.isNoneBlank(userId)) {
bSysUser = bSysUserService.selectByKey(userId);
if (null != bSysUser) {
//import org.apache.commons.beanutils.BeanMap;
//userMap = new BeanMap(bSysUser);
//import org.apache.commons.beanutils.BeanUtils;
//userMap = BeanUtils.describe(user);
//效果等同
userMap = JSON.parseObject(JSON.toJSONString(bSysUser), new TypeReference<Map<String, String>>() {
});
}
}
return userMap;
}
//import org.apache.commons.beanutils.BeanMap;
//userMap = new BeanMap(bSysUser);
<dependency>
<groupId>commons-beanutils</groupId>
<artifactId>commons-beanutils</artifactId>
<version>1.9.3</version>
</dependency>
``` 感谢楼主分享，支持一下！ 感谢分享！ 如果对象中的参数比Map中的参数多或少，会发生什么？用工具类转换的时候 可以用 第三方 hutools 感謝分享！ hutools 工具好评@#
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