java的一个爬虫

进行抓取页面，我看了一下人家的教程，一般要用到htmlparser用来解析html得到一个网页的相关链接，用httpclient抓取网页数据，
下面是一我写的spider类
package com.openzone.search.spider;




import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.HashSet;
import java.util.Set;




import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;
import org.htmlparser.Node;
import org.htmlparser.NodeFilter;
import org.htmlparser.Parser;
import org.htmlparser.filters.NodeClassFilter;
import org.htmlparser.filters.OrFilter;
import org.htmlparser.lexer.Stream;
import org.htmlparser.tags.LinkTag;
import org.htmlparser.util.NodeList;
import org.htmlparser.util.ParserException;




public class Spider {
/**
* 使用种子初始化url队列
*/
String[] seeds;//种子地址，爬虫首先进入的网页
String line;//获取相关的链接，比如line="http://localhost"，爬虫将只记录以此为开头的地址
String savepath;//存储网页的文件夹
String encoding;//爬虫的编码形式
public Spider(String[] seeds,String line,String savepath,String encoding){
this.seeds=seeds;
this.line=line;
this.savepath=savepath;
this.encoding=encoding;
}
public void init(){
Set<String> seedsSet=new HashSet<String>();
for(int i=0;i<seeds.length;i++){
seedsSet.add(seeds[i]);
}
UrlTables.addToUnvisitedUrlSet(seedsSet);
}
public void run() throws HttpException, IOException, ParserException{
init();
for(int i=0;i<20;i++){
if(UrlTables.getUnvisitedUrl().size()!=0){
String url=UrlTables.getFirstFromVisitedUrSet();
catchPages(url);
UrlTables.addToVisitedUrlSet(url);
UrlTables.addToUnvisitedUrlSet(getUrls(url));
}
}
}

public void catchPages(String url){
String filename=null;
HttpClient httpClient=new HttpClient();
httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(5000);
GetMethod getMethod=new GetMethod(url);
//生成getmthod对象并设置参数
//设置get请求超时5s
getMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 5000);
//设置请求重试处理
getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
new DefaultHttpMethodRetryHandler());
//设置encoding
getMethod.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET,encoding);
getMethod.addRequestHeader("Content-Type", "text/html; charset=UTF-8");  
//执行http get请求
int statusCode;
try {
statusCode = httpClient.executeMethod(getMethod);
System.out.print(statusCode);
if(statusCode==200){
InputStream responseBody=null;
responseBody=getMethod.getResponseBodyAsStream();
filename=getFileNameByUrl(url, getMethod.getResponseHeader("Content-Type").getValue());
if(responseBody!=null)
saveToLocal(responseBody,filename);
System.out.println("getsuccess");

String body="";
body=responseBody.toString();
System.out.println(body);
}else{
System.out.print("getfalse");
}
} catch (HttpException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
/*
* 将catchPages得到的网页的比特流存到本地
*/
public void saveToLocal(InputStream responseBody,String filename) throws IOException{
BufferedReader reader = new BufferedReader(new InputStreamReader(responseBody,encoding));
File file=new File(savepath,filename);
FileOutputStream fileOutputStream=new FileOutputStream(file);
OutputStreamWriter writer=new OutputStreamWriter(fileOutputStream);
String line;
while((line=reader.readLine())!=null){
System.out.println(line);
writer.write(line);
}
writer.flush();
writer.close();

}
/*
* 解析页面的url
*/
public Set<String> getUrls(String url) throws ParserException{
Set<String> links=new HashSet<String>();
Parser parser=new Parser(url);
parser.setEncoding(encoding);
NodeFilter frameFilter=new NodeFilter() {
@Override
public boolean accept(Node node) {
// TODO Auto-generated method stub
if(node.getText().startsWith("frame src=")){
return true;
}else{
return false;
}
}
};
OrFilter linkFilter=new OrFilter(new NodeClassFilter(LinkTag.class),frameFilter);
NodeList list=parser.extractAllNodesThatMatch(linkFilter);
for(int i=0;i<list.size();i++){
Node tag=list.elementAt(i);
if(tag instanceof LinkTag){
LinkTag link=(LinkTag)tag;
String linkUrl=link.getLink();
if(frameFilter.accept(tag)){
//处理<frame>
String frameTxt=tag.getText();
int start=frameTxt.indexOf("src=");
frameTxt=frameTxt.substring(start);
int end=frameTxt.indexOf(" ");
if(end==-1){
end=frameTxt.indexOf(">");
}
String frameUrl=frameTxt.substring(5,end-1);
if(LinkFilter(frameUrl))
links.add(frameUrl);
}else{
//处理<a>
if(LinkFilter(linkUrl)){
links.add(linkUrl);
}
}
}
}
return links;
}
//爬虫遵循的线索
public boolean LinkFilter(String url){
if(url.startsWith(line)){
return true;
}else{
return false;
}
}

//网页名filter，不然会出现存储错误
public String getFileNameByUrl(String url,String contentType){
//移除http;
url=url.substring(7);
//text/html类型
if(contentType.indexOf("html")!=-1){
url=url.replaceAll("[\\?/:*|<>\"]", "_")+".html";
return url;
}else{
return url.replaceAll("[\\?/:*|<>\"]","_")+"."+
contentType.substring(contentType.lastIndexOf("/")+1);
}
}
}
//下面是存储地址的类
package com.openzone.search.spider;




import java.util.HashSet;
import java.util.LinkedList;
import java.util.Set;




public class UrlTables {
private static Set<String> visitedUrlSet=new HashSet();
private static LinkedList unvisitedUrlSet=new LinkedList();
public static Set getVisitedUrl() {
return visitedUrlSet;
}
public static void setVisitedUrl(Set visitedUrl) {
UrlTables.visitedUrlSet = visitedUrl;
}
public static LinkedList getUnvisitedUrl() {
return unvisitedUrlSet;
}
public static void setUnvisitedUrl(LinkedList unvisitedUrl) {
UrlTables.unvisitedUrlSet = unvisitedUrl;
}
public static void addToVisitedUrlSet(String url){
visitedUrlSet.add(url);
}
public static boolean IsUnvisitedUrlSetEmpty(){
boolean isEmpty=false;
if(unvisitedUrlSet.isEmpty()){
isEmpty=true;
}
return isEmpty; 
}
public static void addToUnvisitedUrlSet(Set<String> urls){
for (String url : urls) {
if(!isVisited(url)){
unvisitedUrlSet.add(url);
}
}
}
public static boolean isVisited(String url){
boolean isVisited=false;
for (String visitedUrl : visitedUrlSet) {
if(visitedUrl.equals(url)){
isVisited=true;
}
}
return isVisited;
}
public static String getFirstFromVisitedUrSet(){
String url=unvisitedUrlSet.getFirst().toString();
unvisitedUrlSet.removeFirst();
return url;
}
}
//下面实例化爬虫进行工作
package com.openzone.search.spider;




import java.io.IOException;




import org.apache.commons.httpclient.HttpException;
import org.htmlparser.util.ParserException;




public class SpiderRun {




/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
String[] seeds={"http://localhost/openzone/"};
String line="http://localhost";
String savepath="D:\\javaworkspace\\openzone";
String encoding="utf-8";
Spider spider=new Spider(seeds, line, savepath, encoding);
try {
spider.run();
} catch (HttpException e) {
e.printStackTrace();
// TODO Auto-generated catch block
} catch (ParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}




}