怎么查找UTF-8字符串中的字符串？(字符编码有关问题)

如何查找UTF-8字符串中的字符串？(字符编码问题)
我用apache httpclient 4.1.1抓取网页，用String的indexof方法搜索其中是否含有感兴趣的关键字，搜索GBK、GB2312编码网页时正常，遇到UFT-8编码网页就无法搜索，抓取下来的中文内容打印出来也是无法辨认。肯定是编码问题了，不知该怎么解决。搜索了好长时间，试了各种转换编码方法，但都不能把抓取下来的中文内容正常打印出来，搜索也都是-1.

[解决办法]
看楼主也很纠结的；当学习，下载了apache httpclient 4.1.3，给个示例(使用探测工具探测编码失败，就不写了):

Java code

import java.io.BufferedReader;import java.io.InputStreamReader;import org.apache.http.HttpResponse;import org.apache.http.HttpStatus;import org.apache.http.client.HttpClient;import org.apache.http.client.methods.HttpPost;import org.apache.http.impl.client.DefaultHttpClient;public class EncodedPostTest {    public static void main(String[] args) throws Exception {        HttpClient httpclient = new DefaultHttpClient();        BufferedReader bufReader = null;        String charset = "";        try {            HttpPost httppost = new HttpPost(                    "http://localhost:8080/TestJEEProject/EncodingServlet");            HttpResponse response = httpclient.execute(httppost);            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {                if (response.getEntity().getContentEncoding() != null) {                    charset = response.getEntity().getContentEncoding().getValue();                }else if(response.getEntity().getContentType() != null){                    String contentType = response.getEntity().getContentType().getValue().toLowerCase().replaceAll("\\s*", "");                    charset = contentType.substring(contentType.indexOf("charset=") + "charset=".length());                }else{//                    //TODO: 使用默认字符编码                    charset = "gbk";                }                                System.out.println("Charset : " + charset);                                bufReader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), charset));                String strValue = bufReader.readLine();                while(strValue != null){                    if(strValue.indexOf("编码") != -1){                        System.out.println(strValue);                    }                    strValue = bufReader.readLine();                }                            } else {                System.out.println("Unexpected failure: "                        + response.getStatusLine().toString());            }        } finally {            httpclient.getConnectionManager().shutdown();            if(bufReader != null){                bufReader.close();            }        }    }}