根据URL抓取网页内容

准备工作

??? 需要下载jar包：commons-httpclient???

???下载地址：http://hc.apache.org/downloads.cgi?4.1.2?

?? 2.?? 获取网页内容

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package cn.edu.xmu.utils;import java.util.regex.Matcher;import java.util.regex.Pattern;import org.apache.http.Header;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.HttpStatus;import org.apache.http.client.HttpClient;import org.apache.http.client.methods.HttpGet;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.util.EntityUtils;public class WebPageGetter {public static String getWebPage(String url) throws Exception {// 初始化，与3.1中不同HttpClient httpclient = new DefaultHttpClient();// HttpHost targetHost = new HttpHost("http://www.kinkbomb.com/p/9699");// HttpGet httpget = new HttpGet("http://www.apache.org/");HttpGet httpget = new HttpGet(url);// 查看默认request头部信息System.out.println("Accept-Charset:"+ httpget.getFirstHeader("Accept-Charset"));// 以下这条如果不加会发现无论你设置Accept-Charset为gbk还是utf-8，他都会默认返回gb2312（本例针对google.cn来说）httpget.setHeader("User-Agent","Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.1.2)");// 用逗号分隔显示可以同时接受多种编码httpget.setHeader("Accept-Language", "zh-cn,zh;q=0.5");httpget.setHeader("Accept-Charset", "GB2312,utf-8;q=0.7,*;q=0.7");// 验证头部信息设置生效System.out.println("Accept-Charset:"+ httpget.getFirstHeader("Accept-Charset").getValue());// Execute HTTP requestSystem.out.println("executing request " + httpget.getURI());// HttpResponse response = httpclient.execute(targetHost, httpget);HttpResponse response = httpclient.execute(httpget);// HttpResponse response = httpclient.execute(httpget);System.out.println("----------------------------------------");System.out.println("Location: " + response.getLastHeader("Location"));System.out.println(response.getStatusLine().getStatusCode());System.out.println(response.getLastHeader("Content-Type"));System.out.println(response.getLastHeader("Content-Length"));System.out.println("----------------------------------------");// 判断页面返回状态判断是否进行转向抓取新链接int statusCode = response.getStatusLine().getStatusCode();if ((statusCode == HttpStatus.SC_MOVED_PERMANENTLY)|| (statusCode == HttpStatus.SC_MOVED_TEMPORARILY)|| (statusCode == HttpStatus.SC_SEE_OTHER)|| (statusCode == HttpStatus.SC_TEMPORARY_REDIRECT)) {// 此处重定向处理 此处还未验证String newUri = response.getLastHeader("Location").getValue();httpclient = new DefaultHttpClient();httpget = new HttpGet(newUri);response = httpclient.execute(httpget);}// Get hold of the response entityHttpEntity entity = response.getEntity();// 查看所有返回头部信息Header headers[] = response.getAllHeaders();int ii = 0;while (ii < headers.length) {System.out.println(headers[ii].getName() + ": "+ headers[ii].getValue());++ii;}// If the response does not enclose an entity, there is no need// to bother about connection releasebyte[] bytes = null;if (entity != null) {// 将源码流保存在一个byte数组当中，因为可能需要两次用到该流，bytes = EntityUtils.toByteArray(entity);String charSet = "";// 如果头部Content-Type中包含了编码信息，那么我们可以直接在此处获取charSet = EntityUtils.getContentCharSet(entity);System.out.println("In header: " + charSet);// 如果头部中没有，那么我们需要 查看页面源码，这个方法虽然不能说完全正确，因为有些粗糙的网页编码者没有在页面中写头部编码信息if (charSet == "") {String regEx = "(?=<meta).*?(?<=charset=[\\'|\\\"]?)([[a-z]|[A-Z]|[0-9]|-]*)";Pattern p = Pattern.compile(regEx, Pattern.CASE_INSENSITIVE);Matcher m = p.matcher(new String(bytes)); // 默认编码转成字符串，因为我们的匹配中无中文，所以串中可能的乱码对我们没有影响Boolean result = m.find();if (m.groupCount() == 1) {charSet = m.group(1);} else {charSet = "";}}System.out.println("Last get: " + charSet);// 至此，我们可以将原byte数组按照正常编码专成字符串输出（如果找到了编码的话）// System.out.println("Encoding string is: " + new String(bytes,// charSet));}httpclient.getConnectionManager().shutdown();return new String(bytes);}}

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