// TestSupport.java
public class TestSupport {

  public int m01(String s) {
    return s.length();
  }

  public int m02(String s) {
    if (s != null)
      return s.length();

    return -1;
  }
}

// Test.java
public class Test {
  String f = null;

  public void test1(String s) {
    if ((System.nanoTime() % 2) == 0 || f != null)
      System.out.println(f.length()); // Null Pointer Dereference (Java) warning issued here 

    if (s != null)
      System.out.println("s01 is null");

    System.out.println(s.length());   // Null Pointer Dereference (Java) warning issued here 
  }

  public void test2(String par) {
    String s = System.currentTimeMillis() % 2 == 0 ? null : "ciao";
    TestSupport ts = new TestSupport();
    int n01 = ts.m01(s);              // Null Parameter Dereference (Java) warning issued here 
    int n02 = ts.m02(s);
                
    if (s != null)
      ts.m01(s);

    ts.m01(par);

    System.out.println(n01 + n02);
  }

  public void test3(String par) {
    if (par != null)
      System.out.println("is non-null");

    new TestSupport().m01(par);       // Null Parameter Dereference (Java) warning issued here 
  }
}

//  ReflectionExample.java 
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;

public class ReflectionExample {
    public static void Method() throws NoSuchFieldException, SecurityException,
                                       ClassNotFoundException, InstantiationException,
                                       IllegalAccessException, IllegalArgumentException,
                                       InvocationTargetException {
            
      Class<?> c = Class.forName(ClassUsedByReflection.class.getName());

      Field success1 = c.getField("ok");
      success1.get(nil());

      Field success2 = c.getField("hi");
      success2.get(new Object());              // arg0 is not null

      Field fail1 = c.getField("hi");
      fail1.get(nil());     // "Null Parameter Dereference (Java)" warning issued here. 

      Field[] fail2 = c.getFields();
      for(Field f : fail2)
          f.get(nil());     // "Null Parameter Dereference (Java)" warning issued here: 
                            // the ClassUsedByReflection class contains at least one instance field.      
    }

    private static class ClassUsedByReflection{
      public String hi = "Hello World!";       // instance field 
      public static String ok = "I am ok!";    // static, so not an instance field
      public ClassUsedByReflection(){ }
    }       

    public static String nil() {
        return null;
    }
}