我有一个java，那就成功了！ https://pastebin.com/VbxeFKFz 现在我想用jdk netbeans制作一个简单的表格，其中包含5个文本字段和按钮以及标签来显示结果，但我有错误，我认为这是因为我使用了我的方法类开始，但我现在不在主类中使用我的方法（我的方法+按钮和工具代码） 我的代码：
package knnjdk;
import java.util.*;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
public class KnnJDK extends Application {
@Override
public void start(Stage primaryStage) {
GridPane grid = new GridPane();
// Labels & inputs Settings
Label number1 = new Label("Data 1 :");
Label number2 = new Label("Data 2 :");
Label number3 = new Label("Data 3 :");
Label number4 = new Label("Data 4 :");
Label number5 = new Label("Data 5 :");
Label resultat1 = new Label("The Result");
TextField txt1 = new TextField();
TextField txt2 = new TextField();
TextField txt3 = new TextField();
TextField txt4 = new TextField();
TextField txt5 = new TextField();
grid.add(number1,0,0);
grid.add(number2,0,1);
grid.add(number3,0,2);
grid.add(number4,0,3);
grid.add(number5,0,4);
grid.add(resultat1,0,6);
grid.add(txt1,1,0);
grid.add(txt2,1,1);
grid.add(txt3,1,2);
grid.add(txt4,1,3);
grid.add(txt5,1,4);
Button butt = new Button();
butt.setText("Applique KPPV");
grid.add(butt,0,5);
// My Main Method
///////////////////////////////////
double insertedInt = Double.parseDouble(txt1.getText());
double insertedInt2 = Double.parseDouble(txt2.getText());
double insertedInt3 = Double.parseDouble(txt3.getText());
double insertedInt4 = Double.parseDouble(txt4.getText());
double insertedInt5 = Double.parseDouble(txt5.getText());
double[] query = {insertedInt, insertedInt2, insertedInt3, insertedInt4, insertedInt5};
int k = 10;// K : Welaya List Counts
List<City> cityList = new ArrayList<City>();
List<Result> resultList = new ArrayList<Result>();
cityList.add(new City(instances[0],"IRIS0"));
cityList.add(new City(instances[1],"IRIS1"));
cityList.add(new City(instances[2],"IRIS2"));
cityList.add(new City(instances[3],"IRIS3"));
cityList.add(new City(instances[4],"IRIS4"));
cityList.add(new City(instances[5],"IRIS5"));
cityList.add(new City(instances[6],"IRIS6"));
cityList.add(new City(instances[7],"IRIS7"));
cityList.add(new City(instances[8],"IRIS8"));
cityList.add(new City(instances[9],"IRIS9"));
//find distances
for(City city : cityList){
double dist = 0.0;
for(int j = 0; j < city.cityAttributes.length; j++){
dist += Math.pow(city.cityAttributes[j] - query[j], 2) ;
}
double distance = Math.sqrt( dist );
resultList.add(new Result(distance,city.cityName));
}
Collections.sort(resultList, new DistanceComparator());
String[] ss = new String[k];
for(int x = 0; x < k; x++){
ss[x] = resultList.get(x).cityName;
}
String majClass = findMajorityClass(ss);
//System.out.println("The Nearest IRIS Class is : "+majClass);
///////////////////////////////////
Scene scene = new Scene(grid, 300, 250);
// Final Action
butt.setOnAction(event->{
resultat1.setText(majClass);
});
primaryStage.setTitle("KNN With JDK");
primaryStage.setScene(scene);
primaryStage.show();
}
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
// My Method
// our Data Base
static double[][] instances = {
{6.300000,2.500000,5.000000,1.900000,3.000000},
{6.900000,3.200000,5.700000,2.300000,3.000000},
{5.100000,3.800000,1.900000,0.400000,1.000000},
{6.600000,2.900000,4.600000,1.300000,2.000000},
{5.700000,4.400000,1.500000,0.400000,1.000000},
{4.600000,3.400000,1.400000,0.300000,1.000000},
{4.300000,3.000000,1.100000,0.100000,1.000000},
{6.900000,3.100000,5.100000,2.300000,3.000000},
{5.100000,3.700000,1.500000,0.400000,1.000000},
{6.100000,2.800000,4.700000,1.200000,2.000000},
};
private static String findMajorityClass(String[] array)
{
//add the String array to a HashSet to get unique String values
Set<String> h = new HashSet<String>(Arrays.asList(array));
//convert the HashSet back to array
String[] uniqueValues = h.toArray(new String[0]);
//counts for unique strings
int[] counts = new int[uniqueValues.length];
// loop thru unique strings and count how many times they appear in origianl array
for (int i = 0; i < uniqueValues.length; i++) {
for (int j = 0; j < array.length; j++) {
if(array[j].equals(uniqueValues[i])){
counts[i]++;
}
}
}
for (int i = 0; i < uniqueValues.length; i++)
System.out.println(uniqueValues[i]);
for (int i = 0; i < counts.length; i++)
System.out.println(counts[i]);
int max = counts[0];
for (int counter = 1; counter < counts.length; counter++) {
if (counts[counter] > max) {
max = counts[counter];
}
}
System.out.println("max # of occurences: "+max);
int freq = 0;
for (int counter = 0; counter < counts.length; counter++) {
if (counts[counter] == max) {
freq++;
}
}
int index = -1;
if(freq==1){
for (int counter = 0; counter < counts.length; counter++) {
if (counts[counter] == max) {
index = counter;
break;
}
}
//System.out.println("one majority class, index is: "+index);
return uniqueValues[index];
} else{//we have multiple modes
int[] ix = new int[freq];//array of indices of modes
System.out.println("multiple majority classes: "+freq+" classes");
int ixi = 0;
for (int counter = 0; counter < counts.length; counter++) {
if (counts[counter] == max) {
ix[ixi] = counter;//save index of each max count value
ixi++; // increase index of ix array
}
}
for (int counter = 0; counter < ix.length; counter++)
System.out.println("class index: "+ix[counter]);
//now choose one at random
Random generator = new Random();
//get random number 0 <= rIndex < size of ix
int rIndex = generator.nextInt(ix.length);
System.out.println("random index: "+rIndex);
int nIndex = ix[rIndex];
//return unique value at that index
return uniqueValues[nIndex];
}
}
private static double meanOfArray(double[] m) {
double sum = 0.0;
for (int j = 0; j < m.length; j++){
sum += m[j];
}
return sum/m.length;
}
//simple class to model instances (features + class)
static class City {
double[] cityAttributes;
String cityName;
public City(double[] cityAttributes, String cityName){
this.cityName = cityName;
this.cityAttributes = cityAttributes;
}
}
//simple class to model results (distance + class)
static class Result {
double distance;
String cityName;
public Result(double distance, String cityName){
this.cityName = cityName;
this.distance = distance;
}
}
//simple comparator class used to compare results via distances
static class DistanceComparator implements Comparator<Result> {
@Override
public int compare(Result a, Result b) {
return a.distance < b.distance ? -1 : a.distance == b.distance ? 0 : 1;
}
}
}
错误：
Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.jav a:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.j ava:389)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
答案 0 :(得分：0)
var bitmapImage = CapturedImages.Last();
PreviewButton1.Content = new Image() { Source = bitmapImage };
我只是设置了文本字段的初始文本，因此它不会引发错误。这不是一个好的编程风格，因为你混合了gui和业务逻辑。也许你应该重构整个程序