SymbolTable

在ClassReader中有两个重要的属性，如下定义：

/** A hashtable containing the encountered top-level and member classes,
 *  indexed by flat names. The table does not contain local classes.
 */
private Map<Name,ClassSymbol> classes;

/** A hashtable containing the encountered packages.
 */
private Map<Name, PackageSymbol> packages;

　　

初始化时是使用SymbolTable中的两个类似的变量定义：

/** A hashtable containing the encountered top-level and member classes,
 *  indexed by flat names. The table does not contain local classes.
 *  It should be updated from the outside to reflect classes defined
 *  by compiled source files.
 */
public final Map<Name, ClassSymbol> classes = new HashMap<Name, ClassSymbol>();

/** A hashtable containing the encountered packages.
 *  the table should be updated from outside to reflect packages defined
 *  by compiled source files.
 */
public final Map<Name, PackageSymbol> packages = new HashMap<Name, PackageSymbol>();