Question

人们！我写了一个Book类，它有Chapter对象（一对多的关系）。它实现了方法public List章节（），如文档中所述。这是Book.java

@Table(name = "Books")
public class Book extends Model implements Serializable {

private static final long serialVersionUID = 1L;

@Column(name = "Name", unique = true, onUniqueConflict = Column.ConflictAction.IGNORE)
public String name;

@Column(name = "Sort")
public int sort;

public Book() {
    super();
}

public Book(String name, int sort) {
    super();
    this.name = name;
    this.sort = sort;
}

public List<Chapter> chapters() {
    return getMany(Chapter.class, "Book");
}

@Override
public String toString() {
    return name;
}
}

在主要活动上，我可以成功获得章节对象。但是，我必须将一个book对象传递给另一个有一个片段的活动，虽然我得到了对象的声明属性（String name和int sort），但当我调用chapter（）时它会引发异常：

Bundle bundle = getIntent().getExtras();
Book book = (Book) bundle.getSerializable("BOOK");

// This line is executed successfully
Log.d("TAGGED", "Recovered book: " + book.name + " has " + book.sort + " as its sort");

// This is the line that throws an exception
ArrayList<Chapter> chapters = book.chapters();

抛出的异常如下：

05-06 15:21:59.701: E/AndroidRuntime(9647): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.hanovit.libraria/com.hanovit.libraria.chapter.ChapterActivity}: java.lang.NullPointerException
05-06 15:21:59.701: E/AndroidRuntime(9647):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
05-06 15:21:59.701: E/AndroidRuntime(9647):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)

05-06 15:21:59.701: E/AndroidRuntime(9647): Caused by: java.lang.NullPointerException
05-06 15:21:59.701: E/AndroidRuntime(9647):     at     com.activeandroid.query.From.getArguments(From.java:207)
05-06 15:21:59.701: E/AndroidRuntime(9647):     at com.activeandroid.query.From.execute(From.java:183)
05-06 15:21:59.701: E/AndroidRuntime(9647):     at com.activeandroid.Model.getMany(Model.java:266)

任何想法有什么不对？感谢!!!

Answer 1

在Github中提交了一个问题，现在已修复（https://github.com/melvin7/ActiveAndroid）

另一方面，只添加列的ID也可以使用附加组件。然后我可以使用

Model.load(Book.class, id)

获得完整的对象

ActiveAndroid模型捆绑附加异常

1 个答案: