单元测试之反射测试私有内部类

场景：测试 私有内部类

目标源码：

public class Demo{
    private static final class ByteArrayHashIndexEntry {
    private int hashCode;
    private byte[] key;
    private byte[] value;
    private ByteArrayHashIndexEntry nextEntry;

    /**
     * @param hashCode
     * @param key
     * @param value
     * @param nextEntry
     */
    public ByteArrayHashIndexEntry( int hashCode, byte[] key, byte[] value, ByteArrayHashIndexEntry nextEntry ) {
      this.hashCode = hashCode;
      this.key = key;
      this.value = value;
      this.nextEntry = nextEntry;
    }

    public boolean equalsKey( byte[] cmpKey ) {
      return equalsByteArray( key, cmpKey );
    }

    @Override
    public boolean equals( Object obj ) {
      ByteArrayHashIndexEntry e = (ByteArrayHashIndexEntry) obj;

      return equalsValue( e.value );
    }

    public boolean equalsValue( byte[] cmpValue ) {
      return equalsByteArray( value, cmpValue );
    }

    public static final boolean equalsByteArray( byte[] value, byte[] cmpValue ) {
      if ( value.length != cmpValue.length ) {
        return false;
      }
      for ( int i = value.length - 1; i >= 0; i-- ) {
        if ( value[i] != cmpValue[i] ) {
          return false;
        }
      }
      return true;
    }

  }

}

测试代码：

public void reflectByteArrayHashIndexEntry() throws Exception{
    Object object = null;
    Class<ByteArrayHashIndex> clazz = ByteArrayHashIndex.class;
    //获取外部类内的所有内部类
    Class<?>[] declaredClasses = clazz.getDeclaredClasses();
    for (Class c : declaredClasses){
      //获取修饰符的整数编码
      int mod = c.getModifiers();
      //返回整数编码对应的修饰符的字符串对象
      String modifier = Modifier.toString(mod);
      //找到被private修饰的内部类
      if (modifier.contains("private")) {
        int hashCode = 1;
        byte[] key = {10,11};
        byte[] value =  {23,24};
          byte[] value1 =  {23,24,25,26};
        //获取内部类的构造方法
        Constructor[] constructors = c.getConstructors();
        //设置访问权限
        AccessibleObject.setAccessible(constructors, true);
        //遍历
        for (Constructor constructor1 : constructors){
          //创建内部类对象
          object = constructor1.newInstance(hashCode, key, value, null);
          if (null != object){
            break;
          }
        }
        Field hashCode1 = c.getDeclaredField("hashCode");
        hashCode1.setAccessible(true);
        hashCode1.set(object,0);
        //获取内部类的方法
        Method equals = c.getMethod("equals", Object.class);
        // 执行
        assertTrue((Boolean) equals.invoke(object, object));
        break;
      }
    }
  }