Android-基础笔记-HTTP (一)

URI

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统一资源标识符
组成：scheme://host/path
1. 访问资源的命名机制
2. 存放资源的主机名称
3. 资源自身的名称，由路径表示

绝对URI： http://www.baidu.com
相对URI：books/ios.pdf

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Uri类

1. schema
2. 主机名
3. 路径

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android Uri类

1. schema:Contentprovider的schema由系统规定content://
2. 主机名(Authority):用于标志ContentProvider，外部调用者可以根据这个标志找到对应的contentprovider
3. 路径(Path):用于表示需要操作的数据，路径的构建根据业务决定:

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相对uri

不包含命名规范信息。路径通常指同一台机器上的资源。可能含有相对标识符，或片段标识符

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URL

统一资源定位
组成 协议://主机[:端口号][/path]
1. 协议
2. 主机:[端口号]
3. 资源具体地址

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HTTP 基础

Http URL 、请求、响应、消息

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HTTP URL

格式：http://host[:port][path]
host:合法的internet主机域名或IP地址
port:端口，为空默认80，非80端口访问需要显示指定
path:没有给出，当url作为uri使用需要加”/”，一般浏览器自动完成

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HTTP 请求

组成
1. 请求行符号开头，后面跟URI、协议版本CRLF结尾，空格分隔。出结尾CRLF不允许单独出现CR或LF
格式：Method Request-URI HTTP-Version CRLF
例如:GET /index.html HTTP/1.1 (CRLF)

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HTTP请求方法

GET方法

GET Request-URI HTTP/1.1
向服务器发送请求，获取资源

POST方法

向服务器发送请求获取资源，请求后附加数据
POST Request-URI HTTP/1.1(CRLF)
…
(CRLF)
…
HTML中get和post无大小写之分，HTTP协议中必须大写

HEAD方法

和GET方法相同，但之请求消息报头，不请求完整内容。响应消息和GET方法获取的是相同的
通常用于测试连接有效性

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HTTP响应

组成
1. 状态行
2. 消息报头
3. 正文

状态行格式：HTTP-Version Status-Code Reason-Phrase(CRLF)

HTTP-Version:协议版本
状态码：三位数 第一个定义响应类别
状态描述：状态码描述

状态码分类
1xx:指示信息–请求接收，继续处理
2xx:成功–请求成功
3xx:重定向–要完成请求必须进一步操作
4xx:客户端错误–请求有语法错误或请求无法实现
5xx:服务端错误–服务器未能实现合法请求

HTTP消息

HTTP消息由客户端到服务器的请求和服务器到客户端响应组成。
请求和响应消息组成：

• 开始行(请求消息-请求行，响应消息-状态行)
• 消息报头(可选)
• 空行(CRLF)
• 消息正文(可选)

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Android Http 请求实现

HTTPURLConnection

POST

public static String requestPostURLConnection(String urlStr, Map<String, String> header, Map<String, String> params) {        HttpURLConnection connection = null;        InputStreamReader in = null;        URL url= null;        try {            //设置请求消息头            url = new URL(urlStr);            Log.d("http", "request:" + urlStr);            connection = (HttpURLConnection) url.openConnection();            //post请求，参数要放在http正文，需要设置为true            //默认情况false            connection.setDoOutput(true);            connection.setDoInput(true);            //post请求不能缓存            connection.setUseCaches(false);            //请求方法为POST默认为GET            connection.setRequestMethod("POST");            //默认编码            connection.setRequestProperty("Charset", "UTF-8");            connection.setConnectTimeout(10 * 1000);//连接超时 毫秒            connection.setReadTimeout(10 * 1000);//读取超时 毫秒            if (header != null && !header.isEmpty()) {                for (String key : header.keySet()) {                    connection.addRequestProperty(key, header.get(key));                }            }            //开始连接            connection.connect();            //提交post参数            if (params != null && !params.isEmpty()) {                DataOutputStream dos = new DataOutputStream(connection.getOutputStream());                Iterator<String> it = params.keySet().iterator();                while (it.hasNext()) {                    String key = it.next();                    String nameValuePair = key + "=" + params.get(key);                    dos.write(nameValuePair.getBytes());                }                dos.flush();                dos.close();            }            //读取响应消息            in = new InputStreamReader(connection.getInputStream());            BufferedReader reader = new BufferedReader(in);            StringBuffer result = new StringBuffer();            String line;            while ((line = reader.readLine()) != null) {                result.append(line);            }            reader.close();            Log.d("http", "result:" + result.toString());            return result.toString();        } catch (MalformedURLException e) {            e.printStackTrace();        } catch (ProtocolException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        } finally {            if (connection != null) {                connection.disconnect();            }            if (in != null) {                try {                    in.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }        return "";    }

GET

public static String requestGetURLConnection(String urlStr, Map<String,String> header,Map<String, String> params) {        HttpURLConnection connection = null;        InputStreamReader in = null;        URL url = null;        try {            if (params != null) {                Iterator<String>it = params.keySet().iterator();                StringBuilder sb = null;                while (it.hasNext()) {                    if (sb == null) {                        sb = new StringBuilder();                        sb.append("?");                    }else {                        sb.append("&");                    }                    String key = it.next();                    sb.append(key).append("=").append(params.get(key));                }                urlStr += sb.toString();            }            url = new URL(urlStr);            Log.d("http", "request url:"+urlStr);            //设置请求消息头            connection = (HttpURLConnection) url.openConnection();            connection.setRequestMethod("GET");            connection.setConnectTimeout(10 * 1000);            connection.setReadTimeout(10 * 1000);            connection.setRequestProperty("Accept-Charset", "UTF-8");            connection.setRequestProperty("Accept-Language", Locale.getDefault().toString());            connection.setRequestProperty("Charset", "UTF-8");            if (header != null && !header.isEmpty()) {                for (String key : header.keySet()) {                    connection.setRequestProperty(key, header.get(key));                }            }            //参数设置完毕，开始连接            connection.connect();            //获取响应            in = new InputStreamReader(connection.getInputStream());            BufferedReader reader = new BufferedReader(in);            StringBuilder buffer = new StringBuilder();            String line ;            while ((line = reader.readLine()) != null) {                buffer.append(line);            }            Log.d("http", "result:" + buffer.toString());            return buffer.toString();        } catch (MalformedURLException e) {            e.printStackTrace();        } catch (ProtocolException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        } finally {            if (connection != null) {                connection.disconnect();            }            if (in != null) {                try {                    in.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }        return "";    }

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HttpClient

post

static DefaultHttpClient client;    public static synchronized DefaultHttpClient getClient() {        if (client == null) {            HttpParams _connParam = new BasicHttpParams();            //设置连接管理器参数            //每台主机最多连接数            ConnManagerParams.setMaxConnectionsPerRoute(_connParam, new ConnPerRouteBean(5));            //连接池最大连接数            ConnManagerParams.setMaxTotalConnections(_connParam, 10);            //从连接池获取连接超时            ConnManagerParams.setTimeout(_connParam, 1000);            //设置协议参数            //设置http协议版本            HttpProtocolParams.setVersion(_connParam, HttpVersion.HTTP_1_1);            //设置编码格式            HttpProtocolParams.setContentCharset(_connParam, HTTP.UTF_8);            //设置浏览器            //HttpProtocolParams.setUserAgent(_connParam, "");            //连接服务器参数            HttpConnectionParams.setConnectionTimeout(_connParam, 10 * 1000);            HttpConnectionParams.setSoTimeout(_connParam, 10 * 1000);            HttpConnectionParams.setSocketBufferSize(_connParam, 1024 * 5);            //设置重定向            HttpClientParams.setRedirecting(_connParam, true);            //注册协议模式            SchemeRegistry schemeRegistry = new SchemeRegistry();            schemeRegistry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));            schemeRegistry.register(new Scheme("https", SSLSocketFactory.getSocketFactory(), 443));            //配置管理多线程安全            ClientConnectionManager manager = new ThreadSafeClientConnManager(_connParam, schemeRegistry);            client = new DefaultHttpClient(manager, _connParam);        }        return client;    }    public static String requestPostHttpClient(String url, Map<String, String> header, Map<String, String> params) {        HttpClient client = getClient();        HttpResponse resp = null;        try {            HttpPost request = new HttpPost(url);            Log.d("http", url + (params == null ? "" : ":" + params.toString()));            //设置消息头            if (header != null && !header.isEmpty()) {                for (String key : header.keySet()) {                    request.setHeader(key, header.get(key));                }            }            //设置参数            if (params != null && !params.isEmpty()) {                List<NameValuePair> paramList = new ArrayList<>();                for (String key : params.keySet()) {                    paramList.add(new BasicNameValuePair(key, params.get(key)));                }                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList, "UTF-8");                request.setEntity(entity);            }            resp = client.execute(request);            if (resp.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {                HttpEntity entity = resp.getEntity();                String result = EntityUtils.toString(entity, "UTF-8");                return result;            }        } catch (UnsupportedEncodingException e) {            e.printStackTrace();        } catch (ClientProtocolException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        } finally {            if (resp != null) {                try {                    resp.getEntity().consumeContent();                } catch (IOException e) {                    e.printStackTrace();                }            }        }        return "";    }

参考资料

博客：
http://www.cnblogs.com/mengdd/archive/2013/05/26/3099776.html
http://www.open-open.com/lib/view/open1351324240738.html

HTTP状态码查询：
http://httpstatus.es/