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
3.2 导入坐标
<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 测试demo，原生HttpClient使用
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();
}
3.3.2 新建HttpClientPostTest.java测试类，测试post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
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如果能直接访问，简单的访问实现。
//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HttpClientUtil
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);
}
}
自定义工具类源码HttpClientUtil。注意导入的依赖
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;
}
}
原文地址：https://www.cnblogs.com/kitor/p/11235762.html
时间： 2024-10-17 07:07:40