Question

我尝试使用for循环从我的表中获取数据，但它发生了零点异常。这是我的代码

for (int i = 0; i < tabel_otapproclInfo.getItems().size(); i++) {
            String s = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getEMPLOYEEID();
            String s2 = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getEMPLOYEENAME();
            String s3 = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getEMPLOYEEDEPT();
            String s4 = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getSTATUS();
            String s5 = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getDATES();
            String u = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getUSERNMAE();

            System.out.println(u + " " + s + " " + s2 + " " + s3 + " " + s4 + " " + s5);
        }

在此代码中 tabel_otapproclInfo是表名

这是错误的

java.lang.NullPointerException at ashoklayland.OTApprovelsController.actionApproverlAll(OTApprovelsController.java:126) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71) at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498)

Answer 1

如果要循环遍历Table中的所有数据，则应采用此方法。在此示例中，Table对象为Person。

for (int i = 0; i < table.getItems().size(); i++) 
{
    Person tempPerson = table.getItems().get(i);
    System.out.println(tempPerson.getFirstName() + " " + tempPerson.getLastName() + " " + tempPerson.getEmail());
}

如果您想从特定索引Person和index >= 0获取index < table.getItems().size()，请尝试：

Person tempPerson = table.getItems().get(1);
System.out.println("Specifice index 1: " + tempPerson.getFirstName() + " " + tempPerson.getLastName() + " " + tempPerson.getEmail());

如果您想在选择Person之后使用听众。

table.getSelectionModel().selectedItemProperty().addListener((obs, oldSelection, newSelection) -> {
    System.out.println("On Select: " + newSelection.getFirstName() + " " + newSelection.getLastName() + " " + newSelection.getEmail());
});

完整代码：

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.stage.Stage;

public class TableViewSample extends Application
{

    private final TableView<Person> table = new TableView();
    private final ObservableList<Person> data
            = FXCollections.observableArrayList(
                    new Person("Jacob", "Smith", "jacob.smith@example.com"),
                    new Person("Isabella", "Johnson", "isabella.johnson@example.com"),
                    new Person("Ethan", "Williams", "ethan.williams@example.com"),
                    new Person("Emma", "Jones", "emma.jones@example.com"),
                    new Person("Michael", "Brown", "michael.brown@example.com")
            );

    public static void main(String[] args)
    {
        launch(args);
    }

    @Override
    public void start(Stage stage)
    {
        Scene scene = new Scene(new Group());
        stage.setTitle("Table View Sample");
        stage.setWidth(450);
        stage.setHeight(500);

        final Label label = new Label("Address Book");
        label.setFont(new Font("Arial", 20));

        table.setEditable(true);

        TableColumn firstNameCol = new TableColumn("First Name");
        firstNameCol.setMinWidth(100);
        firstNameCol.setCellValueFactory(
                new PropertyValueFactory<Person, String>("firstName"));

        TableColumn lastNameCol = new TableColumn("Last Name");
        lastNameCol.setMinWidth(100);
        lastNameCol.setCellValueFactory(
                new PropertyValueFactory<Person, String>("lastName"));

        TableColumn emailCol = new TableColumn("Email");
        emailCol.setMinWidth(200);
        emailCol.setCellValueFactory(
                new PropertyValueFactory<Person, String>("email"));

        table.setItems(data);
        table.getColumns().addAll(firstNameCol, lastNameCol, emailCol);

        final VBox vbox = new VBox();
        vbox.setSpacing(5);
        vbox.setPadding(new Insets(10, 0, 0, 10));
        vbox.getChildren().addAll(label, table);

        ((Group) scene.getRoot()).getChildren().addAll(vbox);

        stage.setScene(scene);
        stage.show();

        for (int i = 0; i < table.getItems().size(); i++) {
            Person tempPerson = table.getItems().get(i);
            System.out.println(tempPerson.getFirstName() + " " + tempPerson.getLastName() + " " + tempPerson.getEmail());
        }

        Person tempPerson = table.getItems().get(1);
        System.out.println("Specifice index 1: " + tempPerson.getFirstName() + " " + tempPerson.getLastName() + " " + tempPerson.getEmail());

        table.getSelectionModel().selectedItemProperty().addListener((obs, oldSelection, newSelection) -> {
            System.out.println("On Select: " + newSelection.getFirstName() + " " + newSelection.getLastName() + " " + newSelection.getEmail());
        });
    }

    public static class Person
    {

        private final SimpleStringProperty firstName;
        private final SimpleStringProperty lastName;
        private final SimpleStringProperty email;

        private Person(String fName, String lName, String email)
        {
            this.firstName = new SimpleStringProperty(fName);
            this.lastName = new SimpleStringProperty(lName);
            this.email = new SimpleStringProperty(email);
        }

        public String getFirstName()
        {
            return firstName.get();
        }

        public void setFirstName(String fName)
        {
            firstName.set(fName);
        }

        public String getLastName()
        {
            return lastName.get();
        }

        public void setLastName(String fName)
        {
            lastName.set(fName);
        }

        public String getEmail()
        {
            return email.get();
        }

        public void setEmail(String fName)
        {
            email.set(fName);
        }
    }
}

如何从javafx中的表中获取数据

1 个答案: