在房间版本1.1.1中创建复合主键时，无法使用Kotlin编译器构建android studio项目

Question

While I am creating an 'Entity' with a 'primaryKey' annotation over a field to create any SQLite table using room, the Android Studio project builds successfully. But while I am trying to create an 'Entity' with composite primary key, unable to build the project. Unfortunately as I am using 'Dagger 2' in my project unable to see the actual build error.

Note : Project complies with Kotlin compiler.

Code :

@Entity(tableName = "thread_users", primaryKeys = {"thread_id", "user_id"})
public class DMThreadUsers {
    @ColumnInfo(name = "thread_id")
    private String threadId;
    @ColumnInfo(name = "user_id")
    private String userId;
    @ColumnInfo(name = "is_left")
    private boolean isLeft;

    public DMThreadUsers() {
    }

    public String getThreadId() {
        return threadId;
    }

    public void setThreadId(String threadId) {
        this.threadId = threadId;
    }

    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId;
    }

    public boolean isLeft() {
        return isLeft;
    }

    public void setLeft(boolean left) {
        isLeft = left;
    }
}

Answer 1

Primary key fields should be annotated with @NonNull. You have to annotate @NonNull in JAVA for primary key fields and in KOTLIN one need to initialise the primary key fields.

@Entity(tableName = "thread_users", primaryKeys = {"thread_id", "user_id"})
public class DMThreadUsers {
    @NonNull
    @ColumnInfo(name = "thread_id")
    private String threadId;
    @NonNull
    @ColumnInfo(name = "user_id")
    private String userId;
    @ColumnInfo(name = "is_left")
    private boolean isLeft;

    public DMThreadUsers() {
    }

    public String getThreadId() {
        return threadId;
    }

    public void setThreadId(String threadId) {
        this.threadId = threadId;
    }

    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId;
    }

    public boolean isLeft() {
        return isLeft;
    }

    public void setLeft(boolean left) {
        isLeft = left;
    }
}