Question

我在OSX 10.9.2上运行Deducer。我不知道为什么今天我收到这个没有数据查看器的错误：

Loading required package: DeducerExtras
> java.lang.NullPointerException
    at org.rosuda.deducer.JGRConnector.idleEval(JGRConnector.java:39)
    at org.rosuda.deducer.Deducer.idleEval(Deducer.java:611)
    at org.rosuda.deducer.data.DataViewerController.refreshData(DataViewerController.java:212)
    at org.rosuda.deducer.data.DataRefresher.run(DataViewerController.java:252)
    at java.lang.Thread.run(Thread.java:695)

你知道如何解决这个问题吗？

这里是sessionInfo（）

R version 3.0.3 (2014-03-06)
Platform: x86_64-apple-darwin10.8.0 (64-bit)

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] DeducerSpatial_0.7         scales_0.2.4               OpenStreetMap_0.3.1        rgdal_0.8-16               raster_2.2-31              maptools_0.8-29           
 [7] sp_1.0-15                  DeducerPlugInScaling_0.1-0 klaR_0.6-10                mvnormtest_0.1-9           GPArotation_2012.3-1       psych_1.4.4               
[13] DeducerExtras_1.7          irr_0.84                   lpSolve_5.6.8              Deducer_0.7-7              MASS_7.3-33                car_2.0-20                
[19] ggplot2_0.9.3.1            JGR_1.7-16                 iplots_1.1-7               JavaGD_0.6-1               rJava_0.9-6               

loaded via a namespace (and not attached):
 [1] class_7.3-10        cluster_1.15.2      colorspace_1.2-4    combinat_0.0-8      digest_0.6.4        e1071_1.6-3         effects_3.0-0       foreign_0.8-61     
 [9] Formula_1.1-1       grid_3.0.3          gtable_0.1.2        Hmisc_3.14-4        lattice_0.20-29     latticeExtra_0.6-26 multcomp_1.3-3      munsell_0.4.2      
[17] mvtnorm_0.9-99992   nnet_7.3-8          plyr_1.8.1          png_0.1-7           proto_0.3-10        RColorBrewer_1.0-5  Rcpp_0.11.1         reshape2_1.4       
[25] sandwich_2.3-0      splines_3.0.3       stringr_0.6.2       survival_2.37-7     TH.data_1.0-3       tools_3.0.3         zoo_1.7-11

提前致谢

大卫

Answer 1

错误显然JGRConnector实际上是null。检查它为什么会发生在今天。由于它工作较早，我完全相信您使用new关键字创建了一个Object，然后在新创建的Object上调用方法idleEval(String)，如下所示。我是对的吗？

JGRConnector connector = new JGRConnector();
connector.idleEval(StringInput);

希望它有所帮助！

java.lang.NullPointerException（无数据查看器已加载）JGR，Deducer

1 个答案: