Test1-disassembled

Compiled from "Test1.java"
public class Test1 {
  public Test1();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."<init>":()V
       4: return

  public static void main(java.lang.String[]);
    Code:
       0: aconst_null
       1: astore_1
       2: aconst_null
       3: astore_2
       4: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
       7: aload_1
       8: invokevirtual #3                  // Method java/io/PrintStream.println:(Ljava/lang/Object;)V
      11: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
      14: aload_2
      15: invokevirtual #4                  // Method java/io/PrintStream.println:(Ljava/lang/String;)V
      18: return
}

Test1.java

public class Test1 {
    public static void main(String[] args) {
        Object o = null;
        String s = null;
        System.out.println(o);
        System.out.println(s);
    }
}

Test2-disassembled

public class Test2 {
  public Test2();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."<init>":()V
       4: return

  public static void main(java.lang.String[]);
    Code:
       0: aconst_null
       1: astore_1
       2: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
       5: aload_1
       6: invokevirtual #3                  // Method java/io/PrintStream.println:([C)V
       9: return
}

Test2.java

public class Test2 {
    public static void main(String[] args) {
        char[] a = null;
        System.out.println(a);
    }
}