用socket实现的文件服务器(3)

//主题帖cache规则：读则加入，否则不需要加入
private static Cache topicCache = new Cache(300*1000*1000);
//回帖cache
private static Cache replyCache = new Cache(300*1000*1000);

/**
* 取主题贴，首先应该从cache中取
*
* @param forumId
* @param topicId
* @return
*/
public String getTopicContent(int forumId, int topicId)
{
//如果cache中有，就从cache中取
Object content=topicCache.get(forumId+"_"+topicId);
if(content!=null)
{
return content.toString();
}
// 如果cache中没有，就从文件中读
try
{
BufferedReader in = new BufferedReader(new FileReader(getTopicFile(
forumId, topicId)));
String s = new String();
String s2 = new String();
while ((s = in.readLine()) != null)
{
s2 += s;
}
in.close();
//加入cache
topicCache.add(forumId+"_"+topicId,s2);
return s2;
}
catch (Exception e)
{
e.printStackTrace();
}
return "";
}

/**
* 取回贴，首先应该从cache中取
*
* @param forumId
* @param topicId
* @return
*/
public List getReplyList(int forumId, int topicId)
{
//如果cache中有，就从cache中取
Object replyList=replyCache.get(forumId+"_"+topicId);
if(replyList!=null)
{
return (ArrayList)replyList;
}
// 如果cache中没有，就从文件中读
List list = new ArrayList();// 回贴的文件记录的list，不需要分解。分解工作在client来完成
try
{
RandomAccessFile in = new RandomAccessFile(getReplyFile(forumId, topicId),"rw");
String s = new String();
while ((s = in.readLine()) != null)
{
list.add(s);
}
in.close();
//加入到cache中
replyCache.add(forumId+"_"+topicId,list);
}
catch (Exception e)
{
e.printStackTrace();
}
return list;
}

/**
* 发帖
*
* @param forumId
* @param topicId
* @return
*/
public void addTopic(int forumId, int topicId, String content)
{
try
{
String filePath=getTopicPath(forumId, topicId);
// 需要判断文件的目录是否存在
File path=new File(filePath);
if(!path.exists())
{
path.mkdirs();
}
//写入文件
PrintWriter out = new PrintWriter(new FileWriter(getTopicFile(forumId,topicId)));
out.write(content);
out.close();
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
/**
* 续贴
* @param forumId
* @param topicId
* @param content
*/
public void resumeTopic(int forumId, int topicId, String content)
{
try
{
String filePath=getTopicFile(forumId, topicId);
// 需要判断文件的目录是否存在
File path=new File(filePath);
if(!path.exists())
{
path.mkdirs();
}
//写入文件
content=getTopicContent(forumId,topicId)+content;
PrintWriter out = new PrintWriter(new FileWriter(filePath));
out.write(content);
out.close();
//如果cache中有，则需要更新
Object cacheContent=topicCache.get(forumId+"_"+topicId);
if(cacheContent!=null)
{
topicCache.add(forumId+"_"+topicId,content);
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
/**
* 回贴，如果没有回过贴，要新建文件；如果回过，要续加回贴
* @param forumId
* @param topicId
* @return
*/
public void addReply(int forumId, int topicId,String content,String qq,String replyTime)
{
int replyCount=0;//回贴数s
try
{
String filePath=getReplyFile(forumId, topicId);
String replyCountPath=getReplyCountFile(forumId,topicId);
// 需要判断文件是否存在
File file=new File(filePath);
if(!file.exists())//以前没有回过贴，回贴数为0+1=1
{
(new File(getReplyPath(forumId,topicId))).mkdirs();
(new File(getReplyCountPath(forumId,topicId))).mkdirs();
replyCount++;
}
else//以前回过贴，从文件中读出回贴数，并修改为+1
{
DataInputStream in=new DataInputStream(new BufferedInputStream(new FileInputStream(replyCountPath)));
replyCount=in.readInt()+1;
in.close();
}
//修改回贴数
DataOutputStream out=new DataOutputStream(new BufferedOutputStream(new FileOutputStream(replyCountPath)));
out.writeInt(replyCount);
out.close();
//写入文件
RandomAccessFile rf=new RandomAccessFile(filePath,"rw");
rf.seek(rf.length());
String str=new Integer(replyCount)+"\0x1e"+qq+"\0x1e"+replyTime+"\0x1e"+content+"\n";
rf.write(str.getBytes());
rf.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
/**
* 删主题贴和它的回贴
* @param forumId
* @param topicId
* @param content
*/
public void deleteTopic(int forumId, int topicId)
{
try
{
// 需要判断文件是否存在
File path=new File(getTopicFile(forumId, topicId));
if(path.exists())
{
path.delete();
}
//如果cache中有，则需要删除
Object cacheContent=topicCache.get(forumId+"_"+topicId);
if(cacheContent!=null)
{
topicCache.remove(forumId+"_"+topicId);
}
//删除回贴
File reply=new File(getReplyFile(forumId,topicId));
if(reply.exists())
{
reply.delete();
}
File replyCount=new File(getReplyCountFile(forumId,topicId));
if(replyCount.exists())
{
replyCount.delete();
}
//如果cache中有，需要删除
Object replyList=replyCache.get(forumId+"_"+topicId);
if(replyList!=null)
{
replyCache.remove(forumId+"_"+topicId);
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
/**
* 删某个回贴
* @param forumId
* @param topicId
* @param content
*/
public void deleteReply(int forumId, int topicId,int replyId)
{
try
{
//把满足条件的记录写到bak文件中
String filePath=getReplyFile(forumId, topicId);
RandomAccessFile rf=new RandomAccessFile(filePath,"rw");
RandomAccessFile rfBak=new RandomAccessFile(filePath+".bak","rw");
String s;
while((s=rf.readLine())!=null)
{
String[] strs=s.split("\0x1e");
if((new Integer(replyId)).toString().equals(strs[0]))
{
//do nothing
}
else
{
rfBak.write((s+"\n").getBytes());
}
}
rfBak.close();
rf.close();
//原文件删除
File file=new File(filePath);
file.delete();
//新文件改名
File file2=new File(filePath+".bak");
file2.renameTo(new File(filePath));
//如果cache中有，需要删除
Object replyList=replyCache.get(forumId+"_"+topicId);
if(replyList!=null)
{
replyCache.remove(forumId+"_"+topicId);
}
}
catch (Exception e)
{
e.printStackTrace();
}
}