java中PostMethod和HttpPost都可以提交post表单，请问他们有什么区别

Question

PostMethod
HttpPost 尤其是在cookie和保存信息方面有什么不同？求大神解释
我抛砖引玉，上代码！

import java.io.BufferedReader;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Scanner;

import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.cookie.CookiePolicy;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;

public class Byrbt {

/**
 * @param args
 * @throws Exception 
 */
public static void main(String[] args) throws Exception {
    // TODO Auto-generated method stub
    //先下载登陆页面
    URL login=new URL("http://bt.byr.cn/login.php");

    InputStreamReader isr=new InputStreamReader(login.openStream(),"utf-8");

    BufferedReader br=new BufferedReader(isr);

    String line="";

    String html="";

    while((line=br.readLine())!=null){
        //html=html+line+"\n";
        html+=line;
    }

    Document doc=Jsoup.parse(html);

    //找到图片，下载图片

    String imgSrc="";

    imgSrc=doc.body().getElementsByAttribute("method").select("tr").select("img").attr("src").toString();

    String realSrc="http://bt.byr.cn/"+imgSrc;

    System.out.println(realSrc);

    getPhotoFromWeb(realSrc);

    String imgString="";
    String imgHash="";

    imgHash=realSrc.split("imagehash=")[1];

    System.out.println("输入d盘里的验证码");
    Scanner sca =new Scanner(System.in);

    imgString=sca.next();

    //登陆

    HttpClient httpClient=new HttpClient();

    httpClient.getParams().setCookiePolicy(CookiePolicy.BROWSER_COMPATIBILITY);

    PostMethod post = new PostMethod("http://bt.byr.cn/login.php");
    post.setRequestHeader(new Header(
                    "User-Agent",
                    "Mozilla/5.0 /Windows; U; Windows NT 4.1; de; rv:1.9.1.5) Gecko/20091102 Firefox/3.0"));
    post.addParameter("username", "wingrove");
    post.addParameter("password","jiao12" );
    post.addParameter("imagestring",imgString);
    post.addParameter("imagehash",imgHash);


    httpClient.executeMethod(post);

    System.out.println("GET POST STATUS: "+ post.getStatusLine().toString());

// GetMethod get = new GetMethod("http://bt.byr.cn/torrents.php?cat=406");
// get.setRequestHeader(new Header(
// "User-Agent",
// "Mozilla/5.0 /Windows; U; Windows NT 4.1; de; rv:1.9.1.5) Gecko/20091102 Firefox/3.0"));

// httpClient.executeMethod(get);
//

isr=new InputStreamReader(post.getResponseBodyAsStream(),"utf-8");

    br=new BufferedReader(isr);

    line="";
    html="";

    while((line=br.readLine())!=null){
        html=html+line+"\n";
    }

    System.out.println(html);

}
public static void getPhotoFromWeb(String urlString) throws MalformedURLException, Exception{
    //这个程序只适用于网络，不适用于本地可能是由于url的局限

    URL url = new URL(urlString);
    File outFile =new File("d:/CAPTCHA.jpg");
    OutputStream os = new FileOutputStream(outFile);
    InputStream is = url.openStream();
    byte[] buff = new byte[1024];
    while(true) {
        int readed = is.read(buff);
        if(readed == -1) {
            break;
        }
        byte[] temp = new byte[readed];
        System.arraycopy(buff, 0, temp, 0, readed);
        os.write(temp);
    }
    is.close(); 
    os.close();

}

}

private void doPost(String url, Map<String, String> headers, String body) throws IOException {

02 HttpPost post = new HttpPost(url);
03 for (Map.Entry header : headers.entrySet()) {
04 post.setHeader(header.getKey(), header.getValue());
05 }
06 post.setEntity(new StringEntity(body));
07 HttpContext context = createBasicAuthContext("admin", "password");
08 CloseableHttpResponse response = client.execute(host, post, context);
09 try {
10 // status = response.getStatusLine().getStatusCode();
11 // headers = response.getAllHeaders();
12

13 // HttpEntity entity = response.getEntity();
14 // text = IOUtils.toString(entity.getContent(), "ISO-8859-1");
15 } finally {
16 response.close();
17 }
18 }

Answer 1

比如你有一个页面index.html，这个页面有一个文本域,名称是：a，值是123，你用get提交后，你的url会变成：index.html?a=123，在获取的时候，就是从浏览器中回去参数了，而不是表单！
由于是这样，get方式提交表单，参数有限，不能提交大量数据，而且安全性不高！
用post方式提交，就不会使用url传参数，而且数据量几乎没有限制，这样可以提交大量的数据，安全性可靠！（拾人牙慧）