Java模拟HTTP的Get和Post请求

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.URIException;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;
import org.apache.commons.httpclient.util.URIUtil;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
public final class HttpTookit {
        private static Log log = LogFactory.getLog(HttpTookit.class);
       
        public static String doGet(String url, String queryString) {
                String response = null;
                HttpClient client = new HttpClient();
                HttpMethod method = new GetMethod(url);
                try {
                        if (StringUtils.isNotBlank(queryString))
                                method.setQueryString(URIUtil.encodeQuery(queryString));