今天我的代码litepal部分不知怎么就抽了，各种报错，加了特别简单的测试数据库的代码，还是会报错，而且这个代码在另一个demo上是可以跑的，郁闷，代码如下
public class Test extends AppCompatActivity {
    Button button1;
    Button button2;
    TextView textView;
    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout_test);
        button1=findViewById(R.id.test_btn1);
        button2=findViewById(R.id.test_btn2);
        textView=findViewById(R.id.test_text);
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Connector.getDatabase();
                DBtest dBtest=new DBtest();
                dBtest.setString("ssssssssssssssssss");
                dBtest.save();
            }
        });
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                final List<DBtest> dBtestlist=DataSupport.findAll(DBtest.class);
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        textView.setText(dBtestlist.get(0).getString());
                    }
                });

            }
        });
    }
}
报错如下
E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.example.nf0620.hasaki, PID: 26607
                  java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.AssetManager android.content.Context.getAssets()' on a null object reference
                      at android.content.ContextWrapper.getAssets(ContextWrapper.java:82)
                      at org.litepal.util.BaseUtility.isLitePalXMLExists(BaseUtility.java:235)
                      at org.litepal.parser.LitePalAttr.loadLitePalXMLConfiguration(LitePalAttr.java:98)
                      at org.litepal.parser.LitePalAttr.getInstance(LitePalAttr.java:90)
                      at org.litepal.tablemanager.Connector.buildConnection(Connector.java:104)
                      at org.litepal.tablemanager.Connector.getWritableDatabase(Connector.java:63)
                      at org.litepal.tablemanager.Connector.getDatabase(Connector.java:87)
                      at com.example.nf0620.hasaki.Test$1.onClick(Test.java:34)
                      at android.view.View.performClick(View.java:5669)
                      at android.view.View$PerformClick.run(View.java:22546)
                      at android.os.Handler.handleCallback(Handler.java:751)
                      at android.os.Handler.dispatchMessage(Handler.java:95)
                      at android.os.Looper.loop(Looper.java:154)
                      at android.app.ActivityThread.main(ActivityThread.java:6334)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)