JAVA HTTP 请求的POST提交

public class HttpPostUtils {
   
    public static String httpPost(String urlAddress,Map<String, String> paramMap){
        if(paramMap==null){
            paramMap = new HashMap<String, String>();
        }
        String [] params = new String[paramMap.size()];
        int i = 0;
        for(String paramKey:paramMap.keySet()){
            String param = paramKey+"="+paramMap.get(paramKey);
            params[i] = param;
            i++;
        }
        return httpPost(urlAddress, params);
    }
   
    public static String httpPost(String urlAddress,List<String> paramList){
        if(paramList==null){
            paramList = new ArrayList<String>();
        }
        return httpPost(urlAddress, paramList.toArray(new String[0]));
    }
   
    public static String httpPost(String urlAddress,String []params){
        URL url = null;
        HttpURLConnection con  =null;
        BufferedReader in = null;
        StringBuffer result = new StringBuffer();
        try {
            url = new URL(urlAddress);
            con  = (HttpURLConnection) url.openConnection();
            con.setUseCaches(false);
            con.setDoOutput(true);
            con.setRequestMethod("POST");
            String paramsTemp = "";
            for(String param:params){
                if(param!=null&&!"".equals(param.trim())){
                    paramsTemp+="&"+param;
                }
            }
            byte[] b = paramsTemp.getBytes();
            con.getOutputStream().write(b, 0, b.length);
            con.getOutputStream().flush();
            con.getOutputStream().close();
            in = new BufferedReader(new InputStreamReader(con.getInputStream()));
            while (true) {
              String line = in.readLine();
              if (line == null) {
                break;
              }
              else {
                  result.append(line);
              }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            try {
                if(in!=null){
                    in.close();
                }
                if(con!=null){
                    con.disconnect();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result.toString();
    }
}


ava.io.IOException: Server returned HTTP response code: 500 for URL: http://physics.whu.edu.cn/show.asp?id=278

java.io.IOException: Server returned HTTP response code: 403 for URL

但是自己却可以用浏览器访问，发现可能是服务器对我们这种java程序屏蔽了。

因为服务器的安全设置不接受Java程序作为客户端访问，解决方案是设置客户端的User Agent

url = new URL("http://physics.whu.edu.cn/show.asp?id=278");
            HttpURLConnection connection = (HttpURLConnection) url.
                openConnection();
            connection.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");

这样就可以访问了。

评论

1 楼 haoxinren 2014-07-19  

String param = paramKey+"="+paramMap.get(paramMap); 写错了 应该是String param = paramKey+"="+paramMap.get(paramKey);