Room database error

Question

this my Code

@Entity(tableName = "tasks")

public final class Task { private static final String TAG = "Task";

@PrimaryKey
@NonNull
@ColumnInfo(name = "entryId")
private final String mId;

@Nullable
@ColumnInfo(name = "title")
private final String mTitle;

@Nullable
@ColumnInfo(name = "description")
private final String mDescription;

@ColumnInfo(name = "completed")
private final boolean mCompleted;

public Task(@NonNull String Id, @Nullable String Title, @Nullable String Description, boolean Completed) {
    mId = Id;
    mTitle = Title;
    mDescription = Description;
    mCompleted = Completed;
}

/**
 * 这个构造函数用来创建正在执行的任务
 * 新建立的任务不可能马上被完成，
 * 所以这里completed = false
 */
@Ignore
public Task(@Nullable String Title, @Nullable String Description) {
    this(UUID.randomUUID().toString(), Title, Description, false);
}

/**
 * 如果任务已经有了id，那么就创建一个正在执行的任务
 * 新建立的任务不可能马上被完成，
 * 所以这里completed = false
 */
@Ignore
public Task(@NonNull String Id, @Nullable String Title, @Nullable String Description) {
    this(Id, Title, Description, false);
}

/**
 * 使用这个构造函数创建一个已完成的任务
 */
@Ignore
public Task(@Nullable String Title, @Nullable String Description, boolean Completed) {
    this(UUID.randomUUID().toString(), Title, Description, Completed);
}

@Nullable
public String getDescription() {
    return mDescription;
}

@NonNull
public String getId() {
    return mId;
}

@Nullable
public String getTitle() {
    return mTitle;
}

but i got a error,PLEASE HELP ME , this is google MVP sample github:https://github.com/googlesamples/android-architecture/tree/todo-mvp/

AND THIS IS MY ERROR:

Error:(16, 14) error: Entities and Pojos must have a usable public constructor. You can have an empty constructor or a constructor whose parameters match the fields (by name and type). Tried the following constructors but they failed to match: Task(java.lang.String,java.lang.String,java.lang.String,boolean) : [Id : null, Title : null, Description : null, Completed : null]

I'M THE NEW ONE, PLEASE HELP ME,THANK U VERY MUCH !!!!

Gastón Saillén Gastón Saillén · Accepted Answer · 2018-01-24T16:21:06

Remove final from your class

public class Task

and implement an empty constructor

public Task(){}

and dont forget about your setters , you can aim your mouse at your class name and then alt + fn + insert and this will pop up and click setters, select all your variables and do the setters too as you did your getters

for example, one of my variables is pago, so a setter for pago that is an String will be like this

public void setPago(String pago) {
        this.pago = pago;
    }

this is one of my classes for demonstration...

Room database error

1 Answers