Question

我的控制器：

package com.market;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;




@Controller 
public class Controllerx {

    @Autowired
    private View frame;


/*
    private void init() {
        this.frame.addWindowListener(this);
        registerAction(frame.getbEnter(), new AbstractAction() {
            private List<Funcionarios> list; 

            @Override
            public void action() {
                if (!frame.getjLogin().getText().trim().isEmpty() || !frame.getjPassword().getText().trim().isEmpty()) {

                }else {
                    JOptionPane.showMessageDialog(frame, null, "Campo vázio", JOptionPane.INFORMATION_MESSAGE);
                }
            }

            @Override
            public void posAction() {
                cleanUp();
            }
        });
    }
    */
    public void show() {
        frame.setVisible(true);
    }


}

我的主要联系人：

@SpringBootApplication
@EnableAutoConfiguration
public class Market1Application {

    public static void main(String[] args) {
        ConfigurableApplicationContext context = new SpringApplicationBuilder(Market1Application.class).headless(false).run(args);
        Controllerx appLogin = context.getBean(Controllerx.class);
    }

}

我的观点：

package com.market;

import java.awt.FlowLayout;
import java.awt.GridLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

import org.springframework.stereotype.Component;


@Component
public class View extends JFrame{

    private static final int FRAME_WIDTH = 400;
    static final int FRAME_HEIGHT = 350;
    static final int FRAME_X_ORIGIN = 150;
    static final int FRAME_Y_ORIGIN = 150;
    static final int BUTTON_WIDTH = 90;
    static final int BUTTON_HEIGHT = 30;
    private JTextField jLogin;
    private JTextField jPassword;
    private JButton bEnter;
    private JButton bRegister;
    private JPanel loginForm;
    private JLabel loginText;
    private JLabel passwordText;

    public View() {
        setTitle("Login System");
        setSize         (FRAME_WIDTH, FRAME_HEIGHT);
        setLocation     (FRAME_X_ORIGIN, FRAME_Y_ORIGIN);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new FlowLayout());
        setResizable(false);
        initComponents();
    }
    private void initComponents() {
        loginForm = new JPanel(new GridLayout(3,1));
        //buttons
        bRegister = new JButton("Registrar");
        bRegister.setBounds(195, 285, BUTTON_WIDTH, BUTTON_HEIGHT);
        bEnter = new JButton("Registrar");
        bEnter.setBounds(195, 285, BUTTON_WIDTH, BUTTON_HEIGHT);
        //bEnter.setMnemonic(NativeKeyEvent.VC_ENTER);
        //labels
        loginText = new JLabel();
        loginText.setText("Username:");
        passwordText = new JLabel();
        passwordText.setText("Password:");
        //
        loginForm.add(loginText);
        loginForm.add(jLogin);
        loginForm.add(passwordText);
        loginForm.add(jPassword);
        loginForm.add(bEnter);
        loginForm.add(bRegister);
        setVisible(true);
    }

    public void resetForm() {
        jLogin.setText("");
        jPassword.setText("");
    }
    public JTextField getjLogin() {
        return jLogin;
    }
    public void setjLogin(JTextField jLogin) {
        this.jLogin = jLogin;
    }
    public JTextField getjPassword() {
        return jPassword;
    }
    public void setjPassword(JTextField jPassword) {
        this.jPassword = jPassword;
    }
    public JButton getbEnter() {
        return bEnter;
    }
    public void setbEnter(JButton bEnter) {
        this.bEnter = bEnter;
    }

}

我在编译时遇到这些错误，我不知道哪里出错了，我只有这3个类

启动ApplicationContext时出错。显示条件报告在启用“调试”的情况下重新运行您的应用程序。错误 o.s.boot.SpringApplication-应用程序运行失败 org.springframework.beans.factory.UnsatisfiedDependencyException：创建名称为'controllerx'的bean时出错：不满意的依赖关系通过字段“框架”表示；嵌套异常为 org.springframework.beans.factory.BeanCreationException：错误在文件中定义名称为“ view”的bean [C：\ Users \ Gabriel \ eclipse-workspace \ gabrielestudo \ market-1 \ target \ classes \ com \ market \ View.class]：实例化bean失败；嵌套异常为 org.springframework.beans.BeanInstantiationException：失败实例化[com.market.View]：构造函数抛出异常；嵌套的异常是java.lang.NullPointerException org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor $ AutowiredFieldElement.inject（AutowiredAnnotationBeanPostProcessor.java:596）在 org.springframework.beans.factory.annotation.InjectionMetadata.inject（InjectionMetadata.java:90）在 org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties（AutowiredAnnotationBeanPostProcessor.java:374）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean（AbstractAutowireCapableBeanFactory.java:1411）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:592）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean（AbstractAutowireCapableBeanFactory.java:515）在 org.springframework.beans.factory.support.AbstractBeanFactory.lambda $ doGetBean $ 0（AbstractBeanFactory.java:320）在 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton（DefaultSingletonBeanRegistry.java:222）在 org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（AbstractBeanFactory.java:318）在 org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:199）在 org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons（DefaultListableBeanFactory.java:845）在 org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization（AbstractApplicationContext.java:877）在 org.springframework.context.support.AbstractApplicationContext.refresh（AbstractApplicationContext.java:549）在 org.springframework.boot.SpringApplication.refresh（SpringApplication.java:742）在 org.springframework.boot.SpringApplication.refreshContext（SpringApplication.java:389）在 org.springframework.boot.SpringApplication.run（SpringApplication.java:311）在 org.springframework.boot.builder.SpringApplicationBuilder.run（SpringApplicationBuilder.java:139）位于com.market.Market1Application.main（Market1Application.java:16） sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）位于 sun.reflect.NativeMethodAccessorImpl.invoke（未知来源）位于 sun.reflect.DelegatingMethodAccessorImpl.invoke（未知源）位于 java.lang.reflect.Method.invoke（来源未知） org.springframework.boot.devtools.restart.RestartLauncher.run（RestartLauncher.java:49）引起原因：org.springframework.beans.factory.BeanCreationException：创建文件中定义的名称为“ view”的bean时出错 [C：\ Users \ Gabriel \ eclipse-workspace \ gabrielestudo \ market-1 \ target \ classes \ com \ market \ View.class]：实例化bean失败；嵌套异常为 org.springframework.beans.BeanInstantiationException：失败实例化[com.market.View]：构造函数抛出异常；嵌套的异常是java.lang.NullPointerException org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean（AbstractAutowireCapableBeanFactory.java:1303）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance（AbstractAutowireCapableBeanFactory.java:1197）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:555）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean（AbstractAutowireCapableBeanFactory.java:515）在 org.springframework.beans.factory.support.AbstractBeanFactory.lambda $ doGetBean $ 0（AbstractBeanFactory.java:320）在 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton（DefaultSingletonBeanRegistry.java:222）在 org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（AbstractBeanFactory.java:318）在 org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:199）在 org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate（DependencyDescriptor.java:277）在 org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency（DefaultListableBeanFactory.java:1251）在 org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency（DefaultListableBeanFactory.java:1171）在 org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor $ AutowiredFieldElement.inject（AutowiredAnnotationBeanPostProcessor.java:593） ...省略了22个共同的框架 org.springframework.beans.BeanInstantiationException：失败实例化[com.market.View]：构造函数抛出异常；嵌套的异常是java.lang.NullPointerException org.springframework.beans.BeanUtils.instantiateClass（BeanUtils.java:184）在 org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate（SimpleInstantiationStrategy.java:87）在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean（AbstractAutowireCapableBeanFactory.java:1295） ...省略了33个共同的框架 java.lang.NullPointerException：在时为null java.awt.Container.addImpl（未知源）在 java.awt.Container.add（未知源）位于 com.market.View.initComponents（View.java:56）在 com.market.View。（View.java:39）在 sun.reflect.NativeConstructorAccessorImpl.newInstance0（本机方法）在sun.reflect.NativeConstructorAccessorImpl.newInstance（未知来源） sun.reflect.DelegatingConstructorAccessorImpl.newInstance（未知源）位于java.lang.reflect.Constructor.newInstance（未知源）在 org.springframework.beans.BeanUtils.instantiateClass（BeanUtils.java:172） ...省略了35个通用框架

Answer 1

您的名称为JTextField的{{1}}变量为空（它是字段，您没有对其进行初始化），这就是为什么这样做时要使用NPE的原因

jLogin

看看loginForm.add(jLogin);类的documentation-JPanel方法部分有一个信息

add
抛出：NullPointerException-如果comp为null

似乎在添加public Component add(Component comp)

时，至少在第 58 行有相同的问题

顺便说一句，您应该仔细阅读日志，因为所有内容都在其中

由以下原因引起：java.lang.NullPointerException：null

在java.awt.Container.addImpl（未知来源）

在java.awt.Container.add（未知来源）

在com.market.View.initComponents（ View.java:56 ）

位于com.market.View。（ View.java:39 ）位于

创建名称为'controllerx'的bean时出错：

1 个答案: