java gson.fromJson 返回空值
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gson.fromJson return null values
提问by PAncho
This is My JSON String : "{'userName' : 'Bachooo'}"
这是我的 JSON 字符串： "{'userName' : 'Bachooo'}"
Converting JSON String to LoginVOlogic is:
将 JSON 字符串转换为LoginVO逻辑是：
Gson gson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation().create();
LoginVO loginFrom = gson.fromJson(jsonInString, LoginVO.class);
System.out.println("userName " + loginFrom.getUserName()); // output null
My LoginVO.classis:
我的LoginVO.class是：
public class LoginVO {
private String userName;
private String password;
public String getUserName()
{
return userName;
}
public void setUserName(String userName)
{
this.userName = userName;
}
public String getPassword()
{
return password;
}
public void setPassword(String password)
{
this.password = password;
}
}
Note I am using jdk 1.8.0_92
注意我使用的是jdk 1.8.0_92
Output of loginForm.getUserName() is NULLinstead of "Bachooo"any idea about this issue?
loginForm.getUserName() 的输出是NULL不是"Bachooo"对这个问题有任何想法？
采纳答案by Vikas Madhusudana
Since you are setting excludeFieldsWithoutExposeAnnotation()configuration on the GsonBuilderyou must put @Exposeannotation on those fields you want to serialize/deserialize.
由于您正在设置excludeFieldsWithoutExposeAnnotation()配置，因此GsonBuilder您必须@Expose在要序列化/反序列化的字段上添加注释。
So in order for excludeFieldsWithoutExposeAnnotation()to serialize/deserialize your fields you must add that annotation:
因此，为了excludeFieldsWithoutExposeAnnotation()序列化/反序列化您的字段，您必须添加该注释：
@Expose
private String userName;
@Expose
private String password;
Or, you could remove excludeFieldsWithoutExposeAnnotation()from the GsinBuilder.
或者，您可以excludeFieldsWithoutExposeAnnotation()从GsinBuilder.
回答by Kumaresan Perumal
Try like this, please. Here is the example class:
请尝试这样。这是示例类：
class AngilinaJoile {
private String name;
// setter
// getter
}
And here is how you deserialize it with Gson:
下面是你如何用 Gson 反序列化它：
Gson gson = new Gson();
String jsonInString = "{'name' : 'kumaresan perumal'}";
AngilinaJoile angel = gson.fromJson(jsonInString, AngilinaJoile.class);
