Number of Public Attributes (NOPA)

The number of Public Attributes (NOPA) is the measure of publicly exposed data of a class. It is the count of public fields.

Default Threshold0

Example:

Class ‘SimplePojo’ have a NOPA of 19 which is high.

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package org.apache.flink.api.java.typeutils;

import static org.junit.Assert.assertTrue;

import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.common.typeutils.CompositeType;
import org.apache.flink.api.java.typeutils.TypeExtractor;
import org.junit.Test;

public class PojoTypeInformationTest {

  public static class SimplePojo {
    public String str;
    public Boolean Bl;
    public boolean bl;
    public Byte Bt;
    public byte bt;
    public Short Shrt;
    public short shrt;
    public Integer Intgr;
    public int intgr;
    public Long Lng;
    public long lng;
    public Float Flt;
    public float flt;
    public Double Dbl;
    public double dbl;
    public Character Ch;
    public char ch;
    public int[] primIntArray;
    public Integer[] intWrapperArray;
  }

  @Test
  public void testSimplePojoTypeExtraction() {
    TypeInformation type = TypeExtractor.getForClass(SimplePojo.class);
    assertTrue("Extracted type is not a composite/pojo type but should be.", type instanceof CompositeType);
  }

  public static class NestedPojoInner {
    public String field;
  }

  public static class NestedPojoOuter {
    public Integer intField;
    public NestedPojoInner inner;
  }

  @Test
  public void testNestedPojoTypeExtraction() {
    TypeInformation type = TypeExtractor.getForClass(NestedPojoOuter.class);
    assertTrue("Extracted type is not a Pojo type but should be.", type instanceof CompositeType);
  }

  public static class Recursive1Pojo {
    public Integer intField;
    public Recursive2Pojo rec;
  }

  public static class Recursive2Pojo {
    public String strField;
    public Recursive1Pojo rec;
  }

  @Test
  public void testRecursivePojoTypeExtraction() {
    // This one tests whether a recursive pojo is detected using the set of visited
    // types in the type extractor. The recursive field will be handled using the generic serializer.
    TypeInformation type = TypeExtractor.getForClass(Recursive1Pojo.class);
    assertTrue("Extracted type is not a Pojo type but should be.", type instanceof CompositeType);
  }
  
  @Test
  public void testRecursivePojoObjectTypeExtraction() {
    TypeInformation type = TypeExtractor.getForObject(new Recursive1Pojo());
    assertTrue("Extracted type is not a Pojo type but should be.", type instanceof CompositeType);
  }
  
}