尝试执行以下教程时:
使用Android Studio,我创建了一个Android Studio项目并添加了CheckIn.java类,其中包含以下内容:
import java.util.Date;
import com.google.appengine.api.datastore.Key;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity
public class CheckIn {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private java.security.Key key;
private String placeId;
private String userEmail;
private Date checkinDate;
public java.security.Key getKey() {
return key;
}
public String getPlaceId() {
return placeId;
}
public void setPlaceId(String placeId) {
this.placeId = placeId;
}
public String getUserEmail() {
return userEmail;
}
public void setUserEmail(String userEmail) {
this.userEmail = userEmail;
}
public Date getCheckinDate() {
return checkinDate;
}
public void setCheckinDate(Date date) {
checkinDate = date;
}
}
但是当我尝试在我的Android Studion / gradle项目中构建项目时,我收到以下错误:
Error:(6, 25) error: package javax.persistence does not exist
Error:(7, 25) error: package javax.persistence does not exist
Error:(8, 25) error: package javax.persistence does not exist
Error:(9, 25) error: package javax.persistence does not exist
Error:(11, 2) error: cannot find symbol class Entity
Error:(14, 6) error: cannot find symbol class Id
Error:(15, 6) error: cannot find symbol class GeneratedValue
Error:(6, 25) error: package javax.persistence does not exist
Error:(7, 25) error: package javax.persistence does not exist
Error:(8, 25) error: package javax.persistence does not exist
Error:(9, 25) error: package javax.persistence does not exist
Error:(11, 2) error: cannot find symbol class Entity
Error:(14, 6) error: cannot find symbol class Id
Error:(15, 6) error: cannot find symbol class GeneratedValue
答案 0 :(得分:4)
当我补充说:
compile group: 'javax.persistence', name: 'persistence-api', version: '1.0'
到我的gradle依赖项。如上所述here。