How to get the current class name and method name instance in Java

This article mainly introduces the relevant information about the implementation method of obtaining the current class name and method name in Java. It not only provides the implementation method and compares the efficiency of several methods, friends who need it can refer to it

Java’s implementation method of getting the current class name and method name Here are four methods and comparisons. If you need them, you can refer to them.

             Test each function. If you manually print each class name and function name, so many functions will be exhausting. Java has already prepared a bunch of functions that record itself.

Get the class name:

##

public static void testGetClassName() {
  // 方法1：通过SecurityManager的保护方法getClassContext()
  String clazzName = new SecurityManager() {
    public String getClassName() {
      return getClassContext()[1].getName();
    }
  }.getClassName();
  System.out.println(clazzName);
  // 方法2：通过Throwable的方法getStackTrace()
  String clazzName2 = new Throwable().getStackTrace()[1].getClassName();
  System.out.println(clazzName2);
  // 方法3：通过分析匿名类名称()
  String clazzName3 = new Object() {
    public String getClassName() {
      String clazzName = this.getClass().getName();
      return clazzName.substring(0, clazzName.lastIndexOf('$'));
    }
  }.getClassName();
  System.out.println(clazzName3);
  //方法4：通过Thread的方法getStackTrace()
  String clazzName4 = Thread.currentThread().getStackTrace()[2].getClassName();
  System.out.println(clazzName4);
}

Execute 1,000,000 times,

First method: 1718ms

Second method: 4843ms
Third method: 47ms
Fourth method: 6484ms

Comparison:

1) Is there any usage restriction for method 1?

2) Method 2 obtains the call stack through the exception mechanism, which has the worst performance, but it can provide functions that other methods do not have, and can also obtain method names, line numbers, etc.; but this use is somewhat unconventional;
3) Method 3 just briefly analyzes the name of the anonymous class, which is obviously much simpler, and in fact has the highest performance;
4) Method 4 feels a bit similar to Method 3, and is a bit more formal than Method 3

Get the function name:

public static void testGetFunctionName() {
    // 方法1：通过Throwable的方法getStackTrace()
    String funcName2 = new Throwable().getStackTrace()[1].getMethodName();
    System.out.println(funcName2);
    //方法2：通过Thread的方法getStackTrace()
    String clazzName4 = Thread.currentThread().getStackTrace()[2].getMethodName();
    System.out.println(clazzName4);
  }

Execute 1 million times:

First type: 4856ms

Second type: 6337ms

Explanation:

1. The Exception class inherits from Throwable, so in some places, Exception is used to call getStackTrace. In fact, the call is still Throwable

2. The arrays obtained after calling getStackTrace are different in different jdk versions. You will know after trying the subscript a few times. The above is the
under jdk1.6 version.

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