Servlet

最新推荐文章于 2020-11-07 14:26:52 发布

bianshaopeng

最新推荐文章于 2020-11-07 14:26:52 发布

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分类专栏： Servlet 文章标签： servlet

本文链接：https://blog.youkuaiyun.com/bianshaopeng/article/details/47654835

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本文详细介绍了通过doGet和doPost方法进行HTTP请求的具体实现过程，并对比了两种方法在客户端和服务端的不同处理方式，包括参数传递、编码格式转换及响应处理。

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servlet的方法

总结：doGet doPost HttpClientdoGet方法中输入的默认的字体格式是ISO-8859-1必须把它转换为TUF-8的格式,但是HttpClientdoPost不需要转换格式

doGet

客户端

try {
                    //直接跟在URL后面是doGet方法
                    URL url=new URL("http://localhost:8080/WebDay12/Myservlet?username=zhangsan&userPassword=123456");
                    //打开URL连接
                    URLConnection connect=url.openConnection();
                    //强制转换为HTTPURLConnectio
                    HttpURLConnection httpconnection=(HttpURLConnection) connect;
                    //设置请求方式
                    httpconnection.setRequestMethod("GET");
                    //设置连接超时
                    httpconnection.setConnectTimeout(3000);
                    //设置读取超时
                    httpconnection.setReadTimeout(3000);
                    //设置编码格式
                    //设置接受数据类型
                    httpconnection.setRequestProperty("Accept-Charset", "utf-8");
                    //设置可以接受的序列化Java对象
                    httpconnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                    int code=httpconnection.getResponseCode();
                    System.out.println("HTTP 状态码"+code);
                    if(code==HttpURLConnection.HTTP_OK){
                        InputStream is=httpconnection.getInputStream();
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        String line=br.readLine();
                        while(line!=null){
                            System.out.println(line);
                            line=br.readLine();
                        }
                    }
                } catch (MalformedURLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }catch(SocketTimeoutException e){
                    System.out.println("连接超时");
                }catch(ConnectException e){
                    System.out.println("拒绝连接");
                }catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

servlet服务器

String userName=request.getParameter("username");
        String userPassword=request.getParameter("userPassword");
        System.out.println("转换前："+userName);
        userName=Encoding.doEncoding(userName);
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Oprepate.newInstance().singIn(userName, userPassword);
        response.setHeader("Content-type", "text/html;charset=UTF-8");      
        response.getWriter().append("用户名："+userName);
        response.getWriter().append("密码"+userPassword);

字体转换

public class Encoding {
    public static String doEncoding(String string){
        try {
            byte[] array = string.getBytes("ISO-8859-1");
            string=new String(array,"UTF-8");
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return string;

    }

}

doPost方法

客户端

String urlString="http://localhost:8080/WebDay12/Myservlet";
                try {
                    URL url=new URL(urlString);
                    URLConnection connection=url.openConnection();
                    HttpURLConnection httpconnection=(HttpURLConnection) connection;
                    //设置连接超时
                    httpconnection.setConnectTimeout(30000);
                    //设置读取超时
                    httpconnection.setReadTimeout(30000);
                    //设置编码格式
                    //设置接受数据类型
                    httpconnection.setRequestProperty("Accept-Charset", "utf-8");
                    //设置可以接受的序列化Java对象
                    httpconnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                    httpconnection.setRequestMethod("POST");
                    //设置可以读取服务器返回的内容，默认为true
                    httpconnection.setDoInput(true);
                    //设置客户端可以给服务器提交数据，默认是false的。post方法必须设置为true
                    httpconnection.setDoOutput(true);
                    //post方法不允许使用缓存
                    httpconnection.setUseCaches(true);
                    String params="username=zhangsan&userPassword=123456";
                    httpconnection.getOutputStream().write(params.getBytes());
                    int code=httpconnection.getResponseCode();
                    System.out.println(code);
                    if(code==HttpURLConnection.HTTP_OK){
                        InputStream is=httpconnection.getInputStream();
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        String line=br.readLine();
                        while(line!=null){
                            System.out.println(line);
                            line=br.readLine();
                        }
                    }
                } catch (MalformedURLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (Throwable e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

servlet服务器

String userName=request.getParameter("username");
        String userPassword=request.getParameter("userPassword");
        System.out.println("转换前："+userName);
        userName=Encoding.doEncoding(userName);
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Oprepate.newInstance().singIn(userName, userPassword);
        response.setHeader("Content-type", "text/html;charset=UTF-8");      
        response.getWriter().append("用户名："+userName);
        response.getWriter().append("密码"+userPassword);

    }

字体格式转换

public class Encoding {
    public static String doEncoding(String string){
        try {
            byte[] array = string.getBytes("ISO-8859-1");
            string=new String(array,"UTF-8");
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return string;

    }

}

HttpClient doGet

客户端

String urlString="http://localhost:8080/WebDay12/Myservlet?username=zhangsan&userPassword=123456";
                HttpClientBuilder builder=HttpClientBuilder.create();
                builder.setConnectionTimeToLive(3000, TimeUnit.MILLISECONDS);
                //生成client
                HttpClient client=builder.build();
                //设置Get方法
                HttpGet get=new HttpGet(urlString);
                //设置服务器接收后的数据的读取方式为utf-8
                get.setHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
                try {
                    //执行get方法得到服务器的返回的所有数据都在response中
                    HttpResponse response=client.execute(get);
                    //HttpClient访问服务器的返回表头，包含http状态码
                    StatusLine statusline=response.getStatusLine();
                    //得到状态码
                    int code=statusline.getStatusCode();
                    System.out.println(code);
                    if(code==HttpURLConnection.HTTP_OK){
                        //得到数据的实体
                        HttpEntity entity=response.getEntity();
                        //得到输入流
                        InputStream is=entity.getContent();
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        String line=br.readLine();
                        while(line!=null){
                            System.out.println(line);
                            line=br.readLine();
                        }
                    }
                } catch (ClientProtocolException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

servlet服务器

String userName=request.getParameter("username");
        String userPassword=request.getParameter("userPassword");
        System.out.println("转换前："+userName);
        userName=Encoding.doEncoding(userName);
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Oprepate.newInstance().singIn(userName, userPassword);
        response.setHeader("Content-type", "text/html;charset=UTF-8");      
        response.getWriter().append("用户名："+userName);
        response.getWriter().append("密码"+userPassword);

    }

字体转换

public class Encoding {
    public static String doEncoding(String string){
        try {
            byte[] array = string.getBytes("ISO-8859-1");
            string=new String(array,"UTF-8");
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return string;

    }

}

HttpclientdoPost

客户端

String urlString="http://localhost:8080/WebDay12/Myservlet";
                HttpClientBuilder builder=HttpClientBuilder.create();
                builder.setConnectionTimeToLive(30000, TimeUnit.MILLISECONDS);
                HttpClient client=builder.build();
                HttpPost post=new HttpPost(urlString);
                NameValuePair pair1=new BasicNameValuePair("username", "zhangsan");
                NameValuePair pair2=new BasicNameValuePair("userPassword", "123456");
                ArrayList<NameValuePair> params=new ArrayList<>();
                params.add(pair1);
                params.add(pair2);
                try {
                    post.setEntity(new UrlEncodedFormEntity(params,"UTF-8"));
                    post.setHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
                    HttpResponse response=client.execute(post);
                    int code=response.getStatusLine().getStatusCode();
                    if(code==HttpURLConnection.HTTP_OK){
                        HttpEntity entity=response.getEntity();
                        InputStream is=entity.getContent();
                        BufferedReader br=new BufferedReader(new InputStreamReader(is));
                        String line=br.readLine();
                        while(line!=null){
                            System.out.println(line);
                            line=br.readLine();
                        }
                    }
                } catch (UnsupportedEncodingException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (ClientProtocolException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }