classdescriptor.java

这个是perst-269.zip下面的SOURCECODE,和大家分享了。

package org.garret.perst.impl;
import  org.garret.perst.*;
import  java.lang.reflect.*;
import  java.util.*;

public final class ClassDescriptor extends Persistent { 
    ClassDescriptor   next;
    String            name;
    boolean           hasReferences;
    FieldDescriptor[] allFields;
    CustomAllocator   allocator;

    static class FieldDescriptor extends Persistent { 
        String          fieldName;
        String          className;
        int             type;
        ClassDescriptor valueDesc;
        transient Field field;

        public boolean equals(FieldDescriptor fd) { 
            return fieldName.equals(fd.fieldName) 
                && className.equals(fd.className)
                && valueDesc == fd.valueDesc
                && type == fd.type;
        }
    }    

    transient Class       cls;
    transient Constructor loadConstructor;
    transient LoadFactory factory;
    transient Object[]    constructorParams;
    transient boolean     hasSubclasses;
    transient boolean     resolved;
    
    static ReflectionProvider reflectionProvider; 

    static boolean            reverseMembersOrder;

    public static final int tpBoolean          = 0;
    public static final int tpByte             = 1;
    public static final int tpChar             = 2;
    public static final int tpShort            = 3;
    public static final int tpInt              = 4;
    public static final int tpLong             = 5;
    public static final int tpFloat            = 6;
    public static final int tpDouble           = 7;
    public static final int tpString           = 8;
    public static final int tpDate             = 9;
    public static final int tpObject           = 10;
    public static final int tpValue            = 11;
    public static final int tpRaw              = 12;
    public static final int tpLink             = 13;
    public static final int tpEnum             = 14;
    public static final int tpCustom           = 15;
    public static final int tpArrayOfBoolean   = 20;
    public static final int tpArrayOfByte      = 21;
    public static final int tpArrayOfChar      = 22;
    public static final int tpArrayOfShort     = 23;
    public static final int tpArrayOfInt       = 24;
    public static final int tpArrayOfLong      = 25;
    public static final int tpArrayOfFloat     = 26;
    public static final int tpArrayOfDouble    = 27;
    public static final int tpArrayOfString    = 28;
    public static final int tpArrayOfDate      = 29;
    public static final int tpArrayOfObject    = 30;
    public static final int tpArrayOfValue     = 31;
    public static final int tpArrayOfRaw       = 32;
    public static final int tpArrayOfLink      = 33; // not supported
    public static final int tpArrayOfEnum      = 34;

    static final String signature[] = {
        "boolean", 
        "byte",
        "char",
        "short",
        "int",
        "long",
        "float",
        "double",
        "String",
        "Date",
        "Object",
        "Value",
        "Raw",
        "Link",
        "enum",
        "", 
        "", 
        "", 
        "", 
        "", 
        "", 
        "ArrayOfBoolean",
        "ArrayOfByte",
        "ArrayOfChar",
        "ArrayOfShort",
        "ArrayOfInt",
        "ArrayOfLong",
        "ArrayOfFloat",
        "ArrayOfDouble",
        "ArrayOfEnum",
        "ArrayOfString",
        "ArrayOfDate",
        "ArrayOfObject",
        "ArrayOfValue",
        "ArrayOfRaw",
        "ArrayOfLink",
        "ArrayOfEnum"
    };
        

    static final int sizeof[] = {
        1, // tpBoolean
        1, // tpByte
        2, // tpChar
        2, // tpShort
        4, // tpInt
        8, // tpLong
        4, // tpFloat
        8, // tpDouble
        0, // tpString
        8, // tpDate
        4, // tpObject
        0, // tpValue
        0, // tpRaw
        0, // tpLink
        4  // tpEnum
     };

    static final Class[] perstConstructorProfile = new Class[]{ClassDescriptor.class};

    static ReflectionProvider getReflectionProvider() { 
        if (reflectionProvider == null) { 
            try {
                Class.forName("sun.misc.Unsafe");
                String cls = "org.garret.perst.impl.sun14.Sun14ReflectionProvider";
                reflectionProvider = (ReflectionProvider)Class.forName(cls).newInstance();
            } catch (Throwable x) { 
                reflectionProvider = new StandardReflectionProvider();
            }
        }
        return reflectionProvider;
    } 
           

    public boolean equals(ClassDescriptor cd) { 
        if (cd == null || allFields.length != cd.allFields.length) { 
            return false;
        }
        for (int i = 0; i < allFields.length; i++) { 
            if (!allFields[i].equals(cd.allFields[i])) { 
                return false;
            }
        }
        return true;
    }
        

    Object newInstance() {
        if (factory != null) { 
            return factory.create(this);
        } else { 
            try { 
                return loadConstructor.newInstance(constructorParams);
            } catch (Exception x) { 
                throw new StorageError(StorageError.CONSTRUCTOR_FAILURE, cls, x);
            }
        }
    }

    void buildFieldList(StorageImpl storage, Class cls, ArrayList list) { 
        Class superclass = cls.getSuperclass();
        if (superclass != null) { 
            buildFieldList(storage, superclass, list);
        }
        Field[] flds = cls.getDeclaredFields();
        if (ClassDescriptor.class.equals(cls)) { 
            for (int i = 0; i < flds.length; i++) { 
                if ((flds[i].getModifiers() & (Modifier.TRANSIENT|Modifier.STATIC)) == 0) {
                    if (!"next".equals(flds[i].getName())) { 
                        reverseMembersOrder = true;
                    }
                    break;
                }
            }
        }
        if (reverseMembersOrder) { 
            for (int i = 0, n = flds.length; i < (n >> 1); i++) { 
                Field f = flds[i];
                flds[i] = flds[n-i-1];
                flds[n-i-1] = f;
            }
        }

        for (int i = 0; i < flds.length; i++) { 
            Field f = flds[i];
            if ((f.getModifiers() & (Modifier.TRANSIENT|Modifier.STATIC)) == 0) {
                try { 
                    f.setAccessible(true);
                } catch (Exception x) {}
                FieldDescriptor fd = new FieldDescriptor();
                fd.field = f;
                fd.fieldName = f.getName();
                fd.className = cls.getName();
                int type = getTypeCode(f.getType());
                switch (type) {
                  case tpObject:
                  case tpLink:
                  case tpArrayOfObject:
                    hasReferences = true;
                    break;
                  case tpValue:
                    fd.valueDesc = storage.getClassDescriptor(f.getType());
                    hasReferences |= fd.valueDesc.hasReferences;                    
                    break;
                  case tpArrayOfValue:
                    fd.valueDesc = storage.getClassDescriptor(f.getType().getComponentType());
                    hasReferences |= fd.valueDesc.hasReferences;
                }
                fd.type = type;
                list.add(fd);
            }
        }