页面中有时候会有这种报错java.lang.NullPointerException: Attempt to read from field 'java.lang.Object android.util.Pair.second' on a null object reference #344

raulbest · 2018-05-03T17:13:36Z

java.lang.NullPointerException: Attempt to read from field 'java.lang.Object android.util.Pair.second' on a null object reference
at com.alibaba.android.vlayout.DelegateAdapter.findAdapterByIndex(DelegateAdapter.java:485)
at com.alibaba.android.vlayout.DelegateAdapter.onCreateViewHolder(DelegateAdapter.java:123)
at android.support.v7.widget.RecyclerView$Adapter.createViewHolder(RecyclerView.java:6493)
at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5680)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5563)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5559)
at com.alibaba.android.vlayout.ExposeLinearLayoutManagerEx$LayoutState.next(ExposeLinearLayoutManagerEx.java:1629)
at com.alibaba.android.vlayout.VirtualLayoutManager$LayoutStateWrapper.next(VirtualLayoutManager.java:1065)
at com.alibaba.android.vlayout.layout.SingleLayoutHelper.layoutViews(SingleLayoutHelper.java:78)
at com.alibaba.android.vlayout.layout.BaseLayoutHelper.doLayout(BaseLayoutHelper.java:318)
at com.alibaba.android.vlayout.VirtualLayoutManager.layoutChunk(VirtualLayoutManager.java:657)
at com.alibaba.android.vlayout.ExposeLinearLayoutManagerEx.fill(ExposeLinearLayoutManagerEx.java:1162)
at com.alibaba.android.vlayout.ExposeLinearLayoutManagerEx.onLayoutChildren(ExposeLinearLayoutManagerEx.java:365)
at com.alibaba.android.vlayout.VirtualLayoutManager.onLayoutChildren(VirtualLayoutManager.java:475)
at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3693)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3410)
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3962)
at android.view.View.layout(View.java:16772)
at android.view.ViewGroup.layout(ViewGroup.java:5462)
at android.support.v4.widget.SwipeRefreshLayout.onLayout(SwipeRefreshLayout.java:611)
at android.view.View.layout(View.java:16772)
at android.view.ViewGroup.layout(ViewGroup.java:5462)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1096)
at android.view.View.layout(View.java:16772)
at android.view.ViewGroup.layout(ViewGroup.java:5462)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:338)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at android.view.View.layout(View.java:16772)
at android.view.ViewGroup.layout(ViewGroup.java:5462)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:338)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at android.view.View.layout(View.java:16772)
at android.view.ViewGroup.layout(ViewGroup.java:5462)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1764)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1607)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1516)
at android.view.View.layout(View.java:16772)
at android.view.ViewGroup.layout(ViewGroup.java:5462)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:338)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at android.view.View.layout(View.java:16772)
at android.view.ViewGroup.layout(ViewGroup.java:5462)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1764)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1607)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1516)
at android.view.View.layout(View.java:16772)
at android.view.ViewGroup.layout(ViewGroup.java:5462)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:338)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at com.android.internal.policy.PhoneWindow$DecorView.onLayout(PhoneWindow.java:2757)
at android.view.View.layout(View.java:16772)
at android.view.ViewGroup.layout(ViewGroup.java:5462)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2234)

JDDJJ · 2018-05-21T09:02:53Z

这种问题大概率是data改变但是视图没有notify 这个问题不常发生但是希望作者还是讲这些异常throw一下否则开发者没办法控制

JDDJJ · 2018-05-21T09:03:25Z

性能问题啊

peerless2012 · 2018-06-06T03:34:38Z

我这里是必现的，我断点发现问题出在Cantor这个类上。
经测试，当返回ViewType比较大的时候，getCantor返回的值经过reverseCantor后不能得到正确的值。

测试代码：
输入：

        public static void main(String[] args) {
		long cantor = Cantor.getCantor(1000052, 0);
		long[] result = new long[2];
		Cantor.reverseCantor(cantor, result);
		System.out.println("index = " + result[1] + ", type = " + result[0]);
	}

输出结果是：

index = -2147483648, type = -2146483596

Fyyvictory · 2018-07-09T08:23:25Z

我现在使用也是有时候出现这个问题，有没有能够改善的方法呢？

raulbest · 2018-12-14T07:39:22Z

我这里是必现的，我断点发现问题出在Cantor这个类上。
经测试，当返回ViewType比较大的时候，getCantor返回的值经过reverseCantor后不能得到正确的值。

测试代码：
输入：
        public static void main(String[] args) {
		long cantor = Cantor.getCantor(1000052, 0);
		long[] result = new long[2];
		Cantor.reverseCantor(cantor, result);
		System.out.println("index = " + result[1] + ", type = " + result[0]);
	}
输出结果是：
index = -2147483648, type = -2146483596

你好，请问这个问题你那边还有再出现过么？怎么解决的？，谢谢

peerless2012 · 2018-12-14T07:43:35Z

我这里是必现的，我断点发现问题出在Cantor这个类上。
经测试，当返回ViewType比较大的时候，getCantor返回的值经过reverseCantor后不能得到正确的值。
测试代码：
输入：
        public static void main(String[] args) {
		long cantor = Cantor.getCantor(1000052, 0);
		long[] result = new long[2];
		Cantor.reverseCantor(cantor, result);
		System.out.println("index = " + result[1] + ", type = " + result[0]);
	}
输出结果是：
index = -2147483648, type = -2146483596
你好，请问这个问题你那边还有再出现过么？怎么解决的？，谢谢

自己转换一下

public class ViewNodeTypeHelper {

    private static final SparseIntArray VIEW_TYPE_MAPPING = new SparseIntArray(30);

    private static final SparseIntArray VIEW_TYPE_UN_MAPPING = new SparseIntArray(30);

    private static AtomicInteger ENCODED_VIEW_TYPE = new AtomicInteger(1);

    public static int encode(int viewType) {
        int encodedViewType = VIEW_TYPE_MAPPING.get(viewType);
        if (encodedViewType <= 0) {
            encodedViewType = ENCODED_VIEW_TYPE.getAndIncrement();
            VIEW_TYPE_MAPPING.put(viewType, encodedViewType);
            VIEW_TYPE_UN_MAPPING.put(encodedViewType, viewType);
        }
        return encodedViewType;
    }

    public static int decode(int encodedViewType) {
        return VIEW_TYPE_UN_MAPPING.get(encodedViewType);
    }

}

raulbest · 2018-12-14T08:41:08Z

@peerless2012 你好，方便加下你WX或QQ么？可能还有几个点想请教你一下（447626696）

raulbest · 2018-12-14T09:06:12Z

我这里是必现的，我断点发现问题出在Cantor这个类上。
经测试，当返回ViewType比较大的时候，getCantor返回的值经过reverseCantor后不能得到正确的值。
测试代码：
输入：
        public static void main(String[] args) {
		long cantor = Cantor.getCantor(1000052, 0);
		long[] result = new long[2];
		Cantor.reverseCantor(cantor, result);
		System.out.println("index = " + result[1] + ", type = " + result[0]);
	}
输出结果是：
index = -2147483648, type = -2146483596
你好，请问这个问题你那边还有再出现过么？怎么解决的？，谢谢

自己转换一下

public class ViewNodeTypeHelper {

    private static final SparseIntArray VIEW_TYPE_MAPPING = new SparseIntArray(30);

    private static final SparseIntArray VIEW_TYPE_UN_MAPPING = new SparseIntArray(30);

    private static AtomicInteger ENCODED_VIEW_TYPE = new AtomicInteger(1);

    public static int encode(int viewType) {
        int encodedViewType = VIEW_TYPE_MAPPING.get(viewType);
        if (encodedViewType <= 0) {
            encodedViewType = ENCODED_VIEW_TYPE.getAndIncrement();
            VIEW_TYPE_MAPPING.put(viewType, encodedViewType);
            VIEW_TYPE_UN_MAPPING.put(encodedViewType, viewType);
        }
        return encodedViewType;
    }

    public static int decode(int encodedViewType) {
        return VIEW_TYPE_UN_MAPPING.get(encodedViewType);
    }

}
``

你好，你是直接把他们Vlayout项目的源码改掉（用ViewNodeTypeHelper替换掉Cantor这个？），然后直接用Module的形式依赖到你们自己的项目中的么？如果是module的话可以打包发我一下么？谢谢（raulbest@qq.com）

peerless2012 · 2018-12-17T02:27:33Z

我这里是必现的，我断点发现问题出在Cantor这个类上。
经测试，当返回ViewType比较大的时候，getCantor返回的值经过reverseCantor后不能得到正确的值。
测试代码：
输入：
        public static void main(String[] args) {
		long cantor = Cantor.getCantor(1000052, 0);
		long[] result = new long[2];
		Cantor.reverseCantor(cantor, result);
		System.out.println("index = " + result[1] + ", type = " + result[0]);
	}
输出结果是：
index = -2147483648, type = -2146483596
你好，请问这个问题你那边还有再出现过么？怎么解决的？，谢谢

自己转换一下

public class ViewNodeTypeHelper {

    private static final SparseIntArray VIEW_TYPE_MAPPING = new SparseIntArray(30);

    private static final SparseIntArray VIEW_TYPE_UN_MAPPING = new SparseIntArray(30);

    private static AtomicInteger ENCODED_VIEW_TYPE = new AtomicInteger(1);

    public static int encode(int viewType) {
        int encodedViewType = VIEW_TYPE_MAPPING.get(viewType);
        if (encodedViewType <= 0) {
            encodedViewType = ENCODED_VIEW_TYPE.getAndIncrement();
            VIEW_TYPE_MAPPING.put(viewType, encodedViewType);
            VIEW_TYPE_UN_MAPPING.put(encodedViewType, viewType);
        }
        return encodedViewType;
    }

    public static int decode(int encodedViewType) {
        return VIEW_TYPE_UN_MAPPING.get(encodedViewType);
    }

}
``

你好，你是直接把他们Vlayout项目的源码改掉（用ViewNodeTypeHelper替换掉Cantor这个？），然后直接用Module的形式依赖到你们自己的项目中的么？如果是module的话可以打包发我一下么？谢谢（raulbest@qq.com）

核心就是这个类，就是在你的Adapter的public int getItemViewType(int position)中返回encode的值，然后createViewHolder()的时候decode一下就好了。

Attect · 2019-01-22T02:31:26Z

我这里是必现的，我断点发现问题出在Cantor这个类上。
经测试，当返回ViewType比较大的时候，getCantor返回的值经过reverseCantor后不能得到正确的值。
测试代码：
输入：
        public static void main(String[] args) {
		long cantor = Cantor.getCantor(1000052, 0);
		long[] result = new long[2];
		Cantor.reverseCantor(cantor, result);
		System.out.println("index = " + result[1] + ", type = " + result[0]);
	}
输出结果是：
index = -2147483648, type = -2146483596
你好，请问这个问题你那边还有再出现过么？怎么解决的？，谢谢

自己转换一下

public class ViewNodeTypeHelper {

    private static final SparseIntArray VIEW_TYPE_MAPPING = new SparseIntArray(30);

    private static final SparseIntArray VIEW_TYPE_UN_MAPPING = new SparseIntArray(30);

    private static AtomicInteger ENCODED_VIEW_TYPE = new AtomicInteger(1);

    public static int encode(int viewType) {
        int encodedViewType = VIEW_TYPE_MAPPING.get(viewType);
        if (encodedViewType <= 0) {
            encodedViewType = ENCODED_VIEW_TYPE.getAndIncrement();
            VIEW_TYPE_MAPPING.put(viewType, encodedViewType);
            VIEW_TYPE_UN_MAPPING.put(encodedViewType, viewType);
        }
        return encodedViewType;
    }

    public static int decode(int encodedViewType) {
        return VIEW_TYPE_UN_MAPPING.get(encodedViewType);
    }

}
``

你好，你是直接把他们Vlayout项目的源码改掉（用ViewNodeTypeHelper替换掉Cantor这个？），然后直接用Module的形式依赖到你们自己的项目中的么？如果是module的话可以打包发我一下么？谢谢（raulbest@qq.com）

直接改DelegateAdapter

public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        if (mHasConsistItemType) {
            Adapter adapter = mItemTypeAry.get(viewType);
            if (adapter != null) {
                return adapter.onCreateViewHolder(parent, viewType);
            }

            return null;
        }


        // reverse Cantor Function
        Cantor.reverseCantor(viewType, cantorReverse);

        int index = (int) cantorReverse[1];
        int subItemType = ViewNodeTypeHelper.decode((int) cantorReverse[0]);

        Adapter adapter = findAdapterByIndex(index);
        if (adapter == null) {
            return null;
        }

        return adapter.onCreateViewHolder(parent, subItemType);
    }

    public int getItemViewType(int position) {
        Pair<AdapterDataObserver, Adapter> p = findAdapterByPosition(position);
        if (p == null) {
            return RecyclerView.INVALID_TYPE;
        }

        int subItemType = p.second.getItemViewType(position - p.first.mStartPosition);

        if (subItemType < 0) {
            // negative integer, invalid, just return
            return subItemType;
        }
        subItemType = ViewNodeTypeHelper.encode(subItemType);
        if (mHasConsistItemType) {
            mItemTypeAry.put(subItemType, p.second);
            return subItemType;
        }


        int index = p.first.mIndex;

        return (int) Cantor.getCantor(subItemType, index);
    }

我这边这样后就好了

MikeAfc added the enhancement label Jun 4, 2018

MikeAfc closed this as completed in a3da84d Jul 30, 2018

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页面中有时候会有这种报错java.lang.NullPointerException: Attempt to read from field 'java.lang.Object android.util.Pair.second' on a null object reference #344

页面中有时候会有这种报错java.lang.NullPointerException: Attempt to read from field 'java.lang.Object android.util.Pair.second' on a null object reference #344

raulbest commented May 3, 2018

JDDJJ commented May 21, 2018

JDDJJ commented May 21, 2018

peerless2012 commented Jun 6, 2018

Fyyvictory commented Jul 9, 2018

raulbest commented Dec 14, 2018

peerless2012 commented Dec 14, 2018

raulbest commented Dec 14, 2018

raulbest commented Dec 14, 2018 •

edited

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peerless2012 commented Dec 17, 2018

Attect commented Jan 22, 2019

页面中有时候会有这种报错java.lang.NullPointerException: Attempt to read from field 'java.lang.Object android.util.Pair.second' on a null object reference #344

页面中有时候会有这种报错java.lang.NullPointerException: Attempt to read from field 'java.lang.Object android.util.Pair.second' on a null object reference #344

Comments

raulbest commented May 3, 2018

JDDJJ commented May 21, 2018

JDDJJ commented May 21, 2018

peerless2012 commented Jun 6, 2018

Fyyvictory commented Jul 9, 2018

raulbest commented Dec 14, 2018

peerless2012 commented Dec 14, 2018

raulbest commented Dec 14, 2018

raulbest commented Dec 14, 2018 • edited Loading

peerless2012 commented Dec 17, 2018

Attect commented Jan 22, 2019

raulbest commented Dec 14, 2018 •

edited

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