java的序列化机制原理分析 - JAVA

rialData(obj, desc); //否则调用默认的序列化方法
}
} finally {
if (extendedDebugInfo) {
debugInfoStack.pop();
}
}
}

然后我们先看看writeClassDesc(desc, false)的实现：
[java]
private void writeClassDesc(ObjectStreamClass desc, boolean unshared)
throws IOException
{
int handle;
if (desc == null) {
writeNull();
} else if (!unshared && (handle = handles.lookup(desc)) != -1) {
writeHandle(handle);
} else if (desc.isProxy()) { //如果是proxy对象，则调用该序列化机制 ,isProxy的判断
//isProxy = Proxy.isProxyClass(cl); Returns true if and only if the specified class was dynamically generated to be a proxy class using the getProxyClass method or the newProxyInstance method.
writeProxyDesc(desc, unshared);
} else {
writeNonProxyDesc(desc, unshared);
}
}

/**
* Writes class descriptor representing a dynamic proxy class to stream.
*/
private void writeProxyDesc(ObjectStreamClass desc, boolean unshared)
throws IOException
{
bout.writeByte(TC_PROXYCLASSDESC); //写入代理对象的标示符
handles.assign(unshared null : desc);

Class cl = desc.forClass();
Class[] ifaces = cl.getInterfaces(); //如果是proxy对象，则写入对象的interfaces的名称
bout.writeInt(ifaces.length); //先写入interface个数
for (int i = 0; i < ifaces.length; i++) {
bout.writeUTF(ifaces[i].getName()); //再写入每个interface的名称
}

bout.setBlockDataMode(true);
annotateProxyClass(cl);
bout.setBlockDataMode(false);
bout.writeByte(TC_ENDBLOCKDATA); //结束标签

writeClassDesc(desc.getSuperDesc(), false);//递归写入父类的序列化信息，因为java是单继承，
}

/**
* Writes class descriptor representing a standard (i.e., not a dynamic
* proxy) class to stream.
*/
private void writeNonProxyDesc(ObjectStreamClass desc, boolean unshared)
throws IOException
{
bout.writeByte(TC_CLASSDESC);//写入class对象的标示符
handles.assign(unshared null : desc);

if (protocol == PROTOCOL_VERSION_1) { //如果非代理类对象的具体class信息，查看下面的方法
// do not invoke class descriptor write hook with old protocol
desc.writeNonProxy(this);
} else {
writeClassDescriptor(desc);
}

Class cl = desc.forClass();
bout.setBlockDataMode(true);
annotateClass(cl);
bout.setBlockDataMode(false);
bout.writeByte(TC_ENDBLOCKDATA);

writeClassDesc(desc.getSuperDesc(), false);//递归写入父类的序列化信息，因为java是单继承，
}

writeClassDescriptor(desc)方法：
[java]
throws IOException
{
desc.writeNonProxy(this);
}

void writeNonProxy(ObjectOutputStream out) throws IOException {
out.writeUTF(name);//写入类的名称
out.writeLong(getSerialVersionUID());//写入类的SerialVersionUID

byte flags = 0;
if (externalizable) {//是否实现externalizable接口
flags |= ObjectStreamConstants.SC_EXTERNALIZABLE;
int protocol = out.getProtocolVersion();
if (protocol != ObjectStreamConstants.PROTOCOL_VERSION_1) {
flags |= ObjectStreamConstants.SC_BLOCK_DATA;
}
} else if (serializable) {//是否实现serializable接口
flags |= ObjectStreamConstants.SC_SERIALIZABLE;
}
if (hasWriteOb

java的序列化机制原理分析(四)