<plugin>  <artifactId>maven-compiler-plugin</artifactId>  <version>3.8.0</version>  <configuration>  <source>1.8</source>  <target>1.8</target>  <encoding>utf8</encoding>  <compilerArgs>  <arg>-parameters</arg>  </compilerArgs>  </configuration>  </plugin>

public class Test {  public static void main(String[] args) throws Exception{  Class clazz = Class.forName("com.test.MethodParameterTest");  Method[] methods = clazz.getMethods();  Constructor[] constructors = clazz.getConstructors();  for (Constructor constructor : constructors) {  System.out.println("+++" + constructor.getName());  Parameter[] parameters = constructor.getParameters();  for (Parameter parameter : parameters) {  printParameter(parameter);  }  }  System.out.println("------------------");  for (Method method : methods) {  System.out.println(method.getName());  Parameter[] parameters = method.getParameters();  for (Parameter parameter : parameters) {  printParameter(parameter);  }  }  }  private static void printParameter(Parameter parameter) {  //参数名  System.out.println("tt" + parameter.getName());  //是否在源码中隐式声明的参数名  System.out.println("ttt implicit:" + parameter.isImplicit());  //类文件中，是否存在参数名  System.out.println("ttt namePresent:" + parameter.isNamePresent());  //是否为虚构参数  System.out.println("ttt synthetic:" + parameter.isSynthetic());  System.out.println("ttt VarArgs:" + parameter.isVarArgs());  }  }

public class SpringTest {  private static final ParameterNameDiscoverer parameterNameDiscoverer = new DefaultParameterNameDiscoverer();  public static void main(String[] args) throws Exception{  Class clazz = Class.forName("com.test.MethodParameterTest");  Method[] methods = clazz.getMethods();  for (Method method : methods) {  System.out.println(method.getName());  //JDK 1.8 + is better.  String[] parameterNames = parameterNameDiscoverer.getParameterNames(method);  if (parameterNames == null) {  continue;  }  for (String pn : parameterNames) {  System.out.println("tt" + pn);  }  }  }  }

public String[] getParameterNames(Method method) {Method originalMethod = BridgeMethodResolver.findBridgedMethod(method);return doGetParameterNames(originalMethod);}@Nullableprivate String[] doGetParameterNames(Executable executable) {Class<?> declaringClass = executable.getDeclaringClass();Map<Executable, String[]> map = this.parameterNamesCache.computeIfAbsent(declaringClass, this::inspectClass);return (map != NO_DEBUG_INFO_MAP ? map.get(executable) : null);}

private Map<Executable, String[]> inspectClass(Class<?> clazz) {InputStream is = clazz.getResourceAsStream(ClassUtils.getClassFileName(clazz));if (is == null) {// We couldn't load the class file, which is not fatal as it// simply means this method of discovering parameter names won't work.if (logger.isDebugEnabled()) {logger.debug("Cannot find '.class' file for class [" + clazz +"] - unable to determine constructor/method parameter names");}return NO_DEBUG_INFO_MAP;}try {ClassReader classReader = new ClassReader(is);Map<Executable, String[]> map = new ConcurrentHashMap<>(32);classReader.accept(new ParameterNameDiscoveringVisitor(clazz, map), 0);return map;}...