corejava第9版

corejava第9版/v2ch06/treeModel/Variable.java

@@ -0,0 +1,72 @@
+package treeModel;
+
+import java.lang.reflect.*;
+import java.util.*;
+
+/**
+ * A variable with a type, name, and value.
+ */
+public class Variable
+{
+   private Class<?> type;
+   private String name;
+   private Object value;
+   private ArrayList<Field> fields;
+
+   /**
+    * Construct a variable.
+    * @param aType the type
+    * @param aName the name
+    * @param aValue the value
+    */
+   public Variable(Class<?> aType, String aName, Object aValue)
+   {
+      type = aType;
+      name = aName;
+      value = aValue;
+      fields = new ArrayList<>();
+
+      // find all fields if we have a class type except we don't expand strings and null values
+
+      if (!type.isPrimitive() && !type.isArray() && !type.equals(String.class) && value != null)
+      {
+         // get fields from the class and all superclasses
+         for (Class<?> c = value.getClass(); c != null; c = c.getSuperclass())
+         {
+            Field[] fs = c.getDeclaredFields();
+            AccessibleObject.setAccessible(fs, true);
+
+            // get all nonstatic fields
+            for (Field f : fs)
+               if ((f.getModifiers() & Modifier.STATIC) == 0) fields.add(f);
+         }
+      }
+   }
+
+   /**
+    * Gets the value of this variable.
+    * @return the value
+    */
+   public Object getValue()
+   {
+      return value;
+   }
+
+   /**
+    * Gets all nonstatic fields of this variable.
+    * @return an array list of variables describing the fields
+    */
+   public ArrayList<Field> getFields()
+   {
+      return fields;
+   }
+
+   public String toString()
+   {
+      String r = type + " " + name;
+      if (type.isPrimitive()) r += "=" + value;
+      else if (type.equals(String.class)) r += "=" + value;
+      else if (value == null) r += "=null";
+      return r;
+   }
+}