Merge pull request #95 from dscho/compatible-serialization

Java-compatible (de)serialization of TreeMap, ArrayList and Number

classpath/java/lang/Number.java

@@ -10,7 +10,9 @@
 
 package java.lang;
 
-public abstract class Number {
+import java.io.Serializable;
+
+public abstract class Number implements Serializable {
   public abstract byte byteValue();
   public abstract short shortValue();
   public abstract int intValue();

classpath/java/util/ArrayList.java

@@ -10,6 +10,10 @@
 
 package java.util;
 
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
 public class ArrayList<T> extends AbstractList<T> implements java.io.Serializable {
   private static final int MinimumCapacity = 16;
 
@@ -183,4 +187,23 @@ public class ArrayList<T> extends AbstractList<T> implements java.io.Serializabl
   public String toString() {
     return Collections.toString(this);
   }
+
+  private void writeObject(ObjectOutputStream out) throws IOException {
+    out.defaultWriteObject();
+    out.writeInt(array.length);
+    for (T o : this) {
+      out.writeObject(o);
+    }
+  }
+
+  private void readObject(ObjectInputStream in)
+      throws ClassNotFoundException, IOException
+  {
+    in.defaultReadObject();
+    int capacity = in.readInt();
+    grow(capacity);
+    for (int i = 0; i < size; i++) {
+      array[i] = in.readObject();
+    }
+  }
 }

classpath/java/util/TreeMap.java

@@ -10,25 +10,37 @@
 
 package java.util;
 
-public class TreeMap<K,V> implements Map<K,V> {
-  private TreeSet<MyEntry<K,V>> set;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
 
-  public TreeMap(final Comparator<K> comparator) {
-    set = new TreeSet(new Comparator<MyEntry<K,V>>() {
-        public int compare(MyEntry<K,V> a, MyEntry<K,V> b) {
-          return comparator.compare(a.key, b.key);
-        }
-      });
+public class TreeMap<K,V> implements Map<K,V> {
+  private final Comparator<K> comparator;
+  private transient TreeSet<MyEntry<K,V>> set;
+
+  public TreeMap(Comparator<K> comparator) {
+    this.comparator = comparator;
+    initializeSet();
   }
 
-  public TreeMap() {
-    this(new Comparator<K>() {
+  private void initializeSet() {
+    final Comparator<K> comparator = this.comparator != null ?
+      this.comparator : new Comparator<K>() {
         public int compare(K a, K b) {
           return ((Comparable) a).compareTo(b);
         }
+      };
+    set = new TreeSet(new Comparator<MyEntry<K,V>>() {
+      public int compare(MyEntry<K,V> a, MyEntry<K,V> b) {
+        return comparator.compare(a.key, b.key);
+      }
     });
   }
 
+  public TreeMap() {
+    this(null);
+  }
+
   public String toString() {
     return Collections.toString(this);
   }
@@ -224,4 +236,26 @@ public class TreeMap<K,V> implements Map<K,V> {
       return new Collections.ValueIterator(set.iterator());
     }
   }
+
+  public final static long serialVersionUID = 0x0cc1f63e2d256ae6l;
+
+  private void writeObject(ObjectOutputStream out) throws IOException {
+    out.defaultWriteObject();
+    out.writeInt(size());
+    for (Entry<K, V> entry : entrySet()) {
+      out.writeObject(entry.getKey());
+      out.writeObject(entry.getValue());
+    }
+  }
+
+  private void readObject(ObjectInputStream in) throws IOException {
+    in.defaultReadObject();
+    initializeSet();
+    int size = in.readInt();
+    for (int i = 0; i < size; i++) try {
+      put((K) in.readObject(), (V) in.readObject());
+    } catch (ClassNotFoundException e) {
+      throw new IOException(e);
+    }
+  }
 }

test/Serialize.java

@@ -3,6 +3,7 @@ import java.io.ByteArrayOutputStream;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.Serializable;
+import java.util.TreeMap;
 
 public class Serialize implements Serializable {
   public static final long serialVersionUID = 1l;
@@ -23,15 +24,44 @@ public class Serialize implements Serializable {
 	  expect(a.equals(b));
   }
 
+  private static String pad(long number, int length) {
+    return pad(Long.toHexString(number), length, '0');
+  }
+
+  private static String pad(String s, int length, char padChar) {
+    length -= s.length();
+    if (length <= 0) {
+      return s;
+    }
+    StringBuilder builder = new StringBuilder();
+    while (length-- > 0) {
+      builder.append(padChar);
+    }
+    return builder.append(s).toString();
+  }
+
   protected static void hexdump(byte[] a) {
+    StringBuilder builder = new StringBuilder();
+    System.err.print(pad(0, 8) + " ");
     for (int i = 0; i < a.length; i++) {
-      if ((i & 0xf) == 0) {
-        System.err.println();
-      }
       String hex = Integer.toHexString(a[i] & 0xff);
       System.err.print(" " + (hex.length() == 1 ? "0" : "") + hex);
+      builder.append(a[i] < 0x20 || a[i] > 0x7f ? '.' : (char)a[i]);
+      if ((i & 0xf) == 0x7) {
+        System.err.print(" ");
+      } else if ((i & 0xf) == 0xf) {
+        System.err.println("  |" + builder + "|");
+        builder.setLength(0);
+        System.err.print(pad(i + 1, 8) + " ");
+      }
     }
-    System.err.println();
+    for (int i = a.length & 0xf; i < 0x10; i++) {
+      System.err.print("   ");
+      if ((i & 0xf) == 0x7) {
+        System.err.print(" ");
+      }
+    }
+    System.err.println("  |" + builder + "|");
   }
 
   private static void expectEqual(byte[] a, int[] b) {
@@ -112,5 +142,51 @@ public class Serialize implements Serializable {
     Serialize unserialized = (Serialize) in2.readObject();
     expectEqual(0x12345678, unserialized.dummy);
     in2.close();
+
+    out.reset();
+    out2 = new ObjectOutputStream(out);
+    TreeMap map = new TreeMap();
+    map.put("key", "value");
+    out2.writeObject(map);
+    out2.close();
+    array = out.toByteArray();
+    expectEqual(array, new int[] {
+      // magic
+      0xac, 0xed,
+      // version
+      0x00, 0x05,
+      // object
+      0x73,
+      // class desc "java.util.TreeMap"
+      0x72, 0, 17, 'j', 'a', 'v', 'a', '.', 'u', 't', 'i', 'l', '.',
+      'T', 'r', 'e', 'e', 'M', 'a', 'p',
+      // serial version UID: 0x0cc1f64e2d266ae6
+      0x0c, 0xc1, 0xf6, 0x3e, 0x2d, 0x25, 0x6a, 0xe6,
+      // flags: SC_SERIALIZABLE | SC_WRITE_METHOD
+      0x03,
+      // 1 field: comparator
+      0, 1, 'L', 0, 10, 'c', 'o', 'm', 'p', 'a', 'r', 'a', 't', 'o', 'r',
+      0x74, 0, 22, 'L', 'j', 'a', 'v', 'a', '/', 'u', 't', 'i', 'l', '/',
+      'C', 'o', 'm', 'p', 'a', 'r', 'a', 't', 'o', 'r', ';',
+      // class annotation
+      0x78,
+      // super class desc
+      0x70,
+      // classdata[]: NULL
+      0x70,
+      // custom TreeMap data writte by TreeMap#writeObject
+      0x77, 4, 0x00 , 0x00, 0x00, 0x01, // (int)1 (== map.size())
+      0x74, 0, 3, 'k', 'e', 'y', // "key"
+      0x74, 0, 5, 'v', 'a', 'l', 'u', 'e', // "value"
+      // end block data
+      0x78
+    });
+    map.put("Hello", "ween");
+    in = new ByteArrayInputStream(array);
+    in2 = new ObjectInputStream(in);
+    map = (TreeMap)in2.readObject();
+    in2.close();
+    expectEqual(1, map.size());
+    expectEqual("value", (String)map.get("key"));
   }
 }