我在尝试编译项目时遇到此错误:
Error:Execution failed for task ':app:compileDebugJavaWithJavac'. java.lang.IllegalArgumentException: intcannot be converted to an Element
还有这个警告:
Warning:Supported source version 'RELEASE_7' from annotation processor 'android.arch.persistence.room.RoomProcessor' less than -source '1.8'
这些是我的数据库相关类:
@Entity(tableName = "users")
public class SerializedUser {
@PrimaryKey(autoGenerate = true)
private int id;
@ColumnInfo(name = "first_name")
private String firstName;
@ColumnInfo(name = "last_name")
private String lastName;
@ColumnInfo(name = "username")
private String username;
public SerializedUser(int id, String firstName, String lastName, String username) {
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.username = username;
}
public int getId() {
return id;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public String getUsername() {
return username;
}
}
@android.arch.persistence.room.Database(entities = {SerializedUser.class}, version = 4)
public abstract class Database extends RoomDatabase {
public abstract UserDao userDao();
private static final String DATABASE_NAME = "weather";
// For Singleton instantiation
private static final Object LOCK = new Object();
private static volatile Database i;
public static Database init(Context context) {
if (i == null) {
synchronized (LOCK) {
if (i == null) {
i = Room.databaseBuilder(context.getApplicationContext(),
Database.class, Database.DATABASE_NAME)
.fallbackToDestructiveMigration().build();
}
}
}
return i;
}
public static boolean isInited(){
return i != null;
}
public static Database getInstance(){
if(i == null)
throw new NullPointerException("Database.getInstance called when Database not initialized");
return i;
}
}
@Dao
public abstract class UserDao {
Converters converters;
public void inject(Converters converters) {
this.converters = converters;
}
@Insert(onConflict = REPLACE)
public abstract void saveNow(SerializedUser user);
@Delete
public abstract void deleteNow(int id);
@Query("DELETE FROM users")
public abstract void deleteAllNow();
@Query("SELECT * FROM users")
public abstract List<SerializedUser> getAllNow();
@Query("SELECT * FROM users ORDER BY last_name ASC")
public abstract LivePagedListProvider<Integer, SerializedUser> usersByLastName();
}
所以当它试图实现数据库类时会发生错误? SerializedUser 上的那个 id 不是问题,我已经把它注释掉了,问题还是一样。尝试清理并重建项目并重新启动 Android Studio(无效并重新启动)。
最佳答案
删除
@Delete
public abstract void deleteNow(int id);
在你的 Dao 中它会起作用
关于java - 房间 IllegalArgumentException : intcannot be converted to an Element,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/47127437/