HttpClient介绍和简单使用流程
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HttpClient
SpringCloud中服务和服务之间的调用全部是使用HttpClient,还有前面使用SolrJ中就封装了HttpClient,在调用SolrTemplate的saveBean方法时就调用HttpClient技术。
当前大部分项目暴漏出来的接口是Http请求,数据格式是JSON格式,但在一些老项目使用的仍然是webService。
HttpClient 提供的主要的功能
(1)实现了所有 HTTP 的方法(GET,POST,PUT,DELETE 等)
(2)支持自动转向
(3)支持 HTTPS 协议
(4)支持代理服务器等
1、关于Http的请求类型(常见)
get、put、post、delete含义与区别
1、GET请求会向数据库发索取数据的请求,从而来获取信息,该请求就像数据库的select操作一样,只是用来查询一下数据,不会修改、增加数据,不会影响资源的内容,即该请求不会产生副作用。无论进行多少次操作,结果都是一样的。
2、与GET不同的是,PUT请求是向服务器端发送数据的,从而改变信息,该请求就像数据库的update操作一样,用来修改数据的内容,但是不会增加数据的种类等,也就是说无论进行多少次PUT操作,其结果并没有不同。
3、POST请求同PUT请求类似,都是向服务器端发送数据的,但是该请求会改变数据的种类等资源,就像数据库的insert操作一样,会创建新的内容。几乎目前所有的提交操作都是用POST请求的。
4、DELETE请求顾名思义,就是用来删除某一个资源的,该请求就像数据库的delete操作。
就像前面所讲的一样,既然PUT和POST操作都是向服务器端发送数据的,那么两者有什么区别呢。。。POST主要作用在一个集合资源之上的(url),而PUT主要作用在一个具体资源之上的(url/xxx),通俗一下讲就是,如URL可以在客户端确定,那么可使用PUT,否则用POST。
数据请求格式
综上所述,我们可理解为以下:
1、POST /url 创建
2、DELETE /url/xxx 删除
3、PUT /url/xxx 更新
4、GET /url/xxx 查看
2、HttpClient的请求类型
实现了所有的Http请求类型,相应的类为
HttpGet、HttpPost、HttpDelete、HttpPut
3、Http的使用流程
3.1 创建sms的war子模块
<dependencies> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>4.5.3</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.28</version> </dependency> </dependencies>
3.3.1 新建HttpClientGetTest.java测试类,测试get请求
public static void main(String[] args) throws IOException //1.打开浏览器 CloseableHttpClient httpClient = HttpClients.createDefault(); //2.声明get请求 HttpGet httpGet = new HttpGet("http://www.baidu.com/s?wd=java"); //3.发送请求 CloseableHttpResponse response = httpClient.execute(httpGet); //4.判断状态码 if(response.getStatusLine().getStatusCode()==200) HttpEntity entity = response.getEntity(); //使用工具类EntityUtils,从响应中取出实体表示的内容并转换成字符串 String string = EntityUtils.toString(entity, "utf-8"); System.out.println(string); //5.关闭资源 response.close(); httpClient.close();
public static void main(String[] args) throws IOException //1.打开浏览器 CloseableHttpClient httpClient = HttpClients.createDefault(); //2.声明get请求 HttpPost httpPost = new HttpPost("https://www.oschina.net/"); //3.开源中国为了安全,防止恶意攻击,在post请求中都限制了浏览器才能访问 httpPost.addHeader("User-Agent","Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (Khtml, like Gecko) Chrome/68.0.3440.106 Safari/537.36"); //4.判断状态码 List<NameValuePair> parameters = new ArrayList<NameValuePair>(0); parameters.add(new BasicNameValuePair("scope", "project")); parameters.add(new BasicNameValuePair("q", "java")); UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters,"UTF-8"); httpPost.setEntity(formEntity); //5.发送请求 CloseableHttpResponse response = httpClient.execute(httpPost); if(response.getStatusLine().getStatusCode()==200) HttpEntity entity = response.getEntity(); String string = EntityUtils.toString(entity, "utf-8"); System.out.println(string); //6.关闭资源 response.close(); httpClient.close();
3.3.3 测试获取运营商品牌数据代码实现
自定义工具类HttpClientUtil
//设置请求地址 HttpClientUtil util=new HttpClientUtil("http://localhost:9101/brand/findAll.do"); //设置请求方式 util.get(); //获取返回内容 String content=util.getContent(); //打印结果 System.out.println("content");
使用HttpClientUtil实现先登录在访问页面
要点:务必保证登录和查询请求是连续的请求。借助的自定义工具类
public class HttpClientTest public static void main(String[] args) //设置用户名和密码 Map<String, String> map = new HashMap<String,String>(); map.put("username", "admin"); map.put("password", "123456"); //需要先通过springSecurity认证 String s1 = HttpClientUtil.doPost("http://localhost:9101/login", map); Map<String, String> brand = new HashMap<String,String>(); brand.put("name", "123456"); brand.put("firstChar", "T"); String jsonMap = JSON.toJSONString(brand); System.out.println(jsonMap); String s2 = HttpClientUtil.doPostJson("http://localhost:9101/brand/add.do", jsonMap); //String s2 = HttpClientUtil.doGet("http://localhost:9101/brand/findAll.do"); System.out.println(s2);
import java.io.IOException; import java.security.GeneralSecurityException; import java.security.cert.CertificateException; import java.security.cert.X509Certificate; import java.text.ParseException; import java.util.HashMap; import java.util.LinkedList; import java.util.List; import java.util.Map; import javax.net.ssl.SSLContext; import javax.net.ssl.SSLException; import javax.net.ssl.SSLSession; import javax.net.ssl.SSLSocket; import javax.net.ssl.TrustManager; import javax.net.ssl.X509TrustManager; import org.apache.http.Consts; import org.apache.http.HttpEntity; import org.apache.http.NameValuePair; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.config.RequestConfig; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpEntityEnclosingRequestBase; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpPut; import org.apache.http.client.methods.HttpUriRequest; import org.apache.http.client.protocol.HttpClientContext; import org.apache.http.conn.scheme.Scheme; import org.apache.http.conn.ssl.SSLConnectionSocketFactory; import org.apache.http.conn.ssl.SSLContextBuilder; import org.apache.http.conn.ssl.SSLSocketFactory; import org.apache.http.conn.ssl.TrustStrategy; import org.apache.http.conn.ssl.X509HostnameVerifier; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.impl.client.HttpClients; import org.apache.http.impl.conn.PoolingHttpClientConnectionManager; import org.apache.http.message.BasicNameValuePair; import org.apache.http.util.EntityUtils; /** * http请求客户端 * * @author Administrator * */ public class HttpClientUtil public static HttpClientContext context = null; static System.out.println("====================begin"); context = HttpClientContext.create(); private String url; private Map<String, String> param; private int statusCode; private String content; private String xmlParam; private boolean isHttps; public boolean isHttps() return isHttps; public void setHttps(boolean isHttps) this.isHttps = isHttps; public String getXmlParam() return xmlParam; public void setXmlParam(String xmlParam) this.xmlParam = xmlParam; public HttpClientUtil(String url, Map<String, String> param) this.url = url; this.param = param; public HttpClientUtil(String url) this.url = url; public void setParameter(Map<String, String> map) param = map; public void addParameter(String key, String value) if (param == null) param = new HashMap<String, String>(); param.put(key, value); public void post() throws ClientProtocolException, IOException HttpPost http = new HttpPost(url); setEntity(http); execute(http); public void put() throws ClientProtocolException, IOException HttpPut http = new HttpPut(url); setEntity(http); execute(http); public void get() throws ClientProtocolException, IOException if (param != null) StringBuilder url = new StringBuilder(this.url); boolean isFirst = true; for (String key : param.keySet()) if (isFirst) url.append("?"); else url.append("&"); url.append(key).append("=").append(param.get(key)); this.url = url.toString(); HttpGet http = new HttpGet(url); execute(http); /** * set http post,put param */ private void setEntity(HttpEntityEnclosingRequestBase http) if (param != null) List<NameValuePair> nvps = new LinkedList<NameValuePair>(); for (String key : param.keySet()) nvps.add(new BasicNameValuePair(key, param.get(key))); // 参数 http.setEntity(new UrlEncodedFormEntity(nvps, Consts.UTF_8)); // 设置参数 if (xmlParam != null) http.setEntity(new StringEntity(xmlParam, Consts.UTF_8)); private void execute(HttpUriRequest http) throws ClientProtocolException, IOException CloseableHttpClient httpClient = null; try if (isHttps) SSLContext sslContext = new SSLContextBuilder() .loadTrustMaterial(null, new TrustStrategy() // 信任所有 public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException return true; ).build(); SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory( sslContext); httpClient = HttpClients.custom().setSSLSocketFactory(sslsf) .build(); else httpClient = HttpClients.createDefault(); CloseableHttpResponse response = httpClient.execute(http,context); try if (response != null) if (response.getStatusLine() != null) statusCode = response.getStatusLine().getStatusCode(); HttpEntity entity = response.getEntity(); // 响应内容 content = EntityUtils.toString(entity, Consts.UTF_8); finally response.close(); catch (Exception e) e.printStackTrace(); finally httpClient.close(); public int getStatusCode() return statusCode; public String getContent() throws ParseException, IOException return content;
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