运行的时候出现下面这段错误代码，不知道什么意思，

Question

    @Test
    public void test(){
//        for (int i = 0; i < 100; i++) {

            int i1 = new Random().nextInt(3);//1,2,3
            String classPath = " ";
            switch (i1){
                case 0:
                    classPath = "java.util.Date";
                    break;
                case 1:
                    classPath = "java.lang.Object";
                    break;
                case 2:
                    classPath = "src.Person.java";
                    break;

            }
            try {
                Object instance = getInstance(classPath);
                System.out.println(instance);
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            } catch (NoSuchMethodException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            } catch (InvocationTargetException e) {
                e.printStackTrace();
            } catch (InstantiationException e) {
                e.printStackTrace();
            }
//        }

    }
    /*
    创建一个指定类的对象。
    classPath:指定类的全类名
     */
    public Object getInstance(String classPath) throws ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        Class aClass = Class.forName(classPath);
        return aClass.getDeclaredConstructor().newInstance();

    }

D:\Java\jdk-17.0.2\bin\java.exe -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA 2020.3.4\lib\idea_rt.jar=50075:C:\Program Files\JetBrains\IntelliJ IDEA 2020.3.4\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\JetBrains\IntelliJ IDEA 2020.3.4\lib\idea_rt.jar;C:\Program Files\JetBrains\IntelliJ IDEA 2020.3.4\plugins\junit\lib\junit5-rt.jar;C:\Program Files\JetBrains\IntelliJ IDEA 2020.3.4\plugins\junit\lib\junit-rt.jar;D:\workspace_idea1\JavaSenior\out\production\day07;C:\Users\x\.m2\repository\junit\junit\4.12\junit-4.12.jar;C:\Users\x\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 NewInstanceTest,test
java.lang.ClassNotFoundException: src.Person.java
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
    at java.base/java.lang.Class.forName0(Native Method)
    at java.base/java.lang.Class.forName(Class.java:375)
    at NewInstanceTest.getInstance(NewInstanceTest.java:52)
    at NewInstanceTest.test(NewInstanceTest.java:31)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:568)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit

Answer 1

路径不对，不需要带后缀，把.java去掉就行了。

classPath = "src.Person.java";
改为：
classPath = "src.Person";