如何创建一个变量名为'toString‘类型的动态类？

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;

public class DynamicClassCreation {
    public static void main(String[] args) throws Exception {
        // 创建一个新的类
        Class<?> dynamicClass = createDynamicClass();

        // 创建一个变量名为'toString'的实例
        Object instance = dynamicClass.newInstance();

        // 设置变量值
        Field field = dynamicClass.getDeclaredField("toString");
        field.setAccessible(true);
        field.set(instance, "Hello, World!");

        // 获取变量值并打印
        System.out.println(field.get(instance));
    }

    private static Class<?> createDynamicClass() throws Exception {
        // 创建一个新的类加载器
        ClassLoader classLoader = DynamicClassCreation.class.getClassLoader();

        // 创建一个新的类
        Class<?> dynamicClass = Class.forName("DynamicClass", false, classLoader);

        // 检查类是否已存在
        if (dynamicClass != null) {
            return dynamicClass;
        }

        // 动态生成类的源代码
        String className = "DynamicClass";
        String classSourceCode = "public class " + className + " { private String toString; }";

        // 使用Java Compiler API编译源代码
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
        StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null);
        JavaFileObject sourceFile = new JavaSourceFromString(className, classSourceCode);
        Iterable<? extends JavaFileObject> compilationUnits = Arrays.asList(sourceFile);
        DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<>();
        JavaCompiler.CompilationTask task = compiler.getTask(null, fileManager, diagnostics, null, null, compilationUnits);
        boolean success = task.call();

        // 检查编译是否成功
        if (!success) {
            throw new RuntimeException("Failed to compile dynamic class");
        }

        // 加载并返回动态生成的类
        dynamicClass = classLoader.loadClass(className);
        return dynamicClass;
    }

    static class JavaSourceFromString extends SimpleJavaFileObject {
        final String code;

        JavaSourceFromString(String name, String code) {
            super(URI.create("string:///" + name.replace('.', '/') + Kind.SOURCE.extension), Kind.SOURCE);
            this.code = code;
        }

        @Override
        public CharSequence getCharContent(boolean ignoreEncodingErrors) {
            return code;
        }
    }
}