HttpClient远程使用大全
一 HttpClient简介
1.1 概述
HttpClient只能以编程的方式通过其API用于传输和接受HTTP消息。主要实现功能：
实现了所有 HTTP 的方法（GET、POST、PUT、HEAD、DELETE、HEAD、OPTIONS 等）
支持 HTTPS 协议
支持代理服务器（Nginx等）等
支持自动（跳转）转向。
1.2 案例工程介绍
1.2.1 工程截图
请求端：16-spt-http-request-demo ：7000 响应端：16-spt-httppush-demo ：8082
1.2.2 引入依赖
org.apache.httpcomponents
httpclient
4.5.5
com.alibaba
fastjson
1.2.47
注：SpringBoot的基本依赖配置，这里就不再多说了
二 实操实例Get方式
2.1 get无参数案例
1.消费者
@RestController
public class HttpClientController {
@RequestMapping("/hc/api")
public String getInfo() throws Exception {
// 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
// 创建Get请求
HttpGet httpGet = new HttpGet("http://localhost:8082/get/noparam");
String result="";
// 响应模型
CloseableHttpResponse response = null;
try {
// 由客户端执行(发送)Get请求
response = httpClient.execute(httpGet);
// 从响应模型中获取响应实体
HttpEntity responseEntity = response.getEntity();
System.out.println("响应状态为:" + response.getStatusLine());
if (responseEntity != null) {
System.out.println("响应内容长度为:" + responseEntity.getContentLength());
result=EntityUtils.toString(responseEntity);
System.out.println("响应内容为:" + result);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
// 释放资源
if (httpClient != null) {
httpClient.close();
}
if (response != null) {
response.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
}
}2.服务者
@RestController
public class HttpClientController {
@RequestMapping("/get/noparam")
public String doGetNoParam(){
return "ok 123!";
}
}截图如下：
3.请求测试
2.2 get有参数：直接拼接URL
1.消费者
@RequestMapping("/hc/get/youcan")
public String youcanOne() {
// 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
// 参数
StringBuffer params = new StringBuffer();
try {
// 字符数据最好encoding以下;这样一来，某些特殊字符才能传过去(如:某人的名字就是“&”,不encoding的话,传不过去)
params.append("name=" + URLEncoder.encode("zhangsan", "utf-8"));
params.append("&");
params.append("age=24");
} catch (UnsupportedEncodingException e1) {
e1.printStackTrace();
}
// 创建Get请求
HttpGet httpGet = new HttpGet("http://localhost:8082/get/youparam1" + "?" + params);
// 响应模型
CloseableHttpResponse response = null;
String result="";
try {
// 配置信息
RequestConfig requestConfig = RequestConfig.custom()
// 设置连接超时时间(单位毫秒)
.setConnectTimeout(5000)
// 设置请求超时时间(单位毫秒)
.setConnectionRequestTimeout(5000)
// socket读写超时时间(单位毫秒)
.setSocketTimeout(5000)
// 设置是否允许重定向(默认为true)
.setRedirectsEnabled(true).build();
// 将上面的配置信息 运用到这个Get请求里
httpGet.setConfig(requestConfig);
// 由客户端执行(发送)Get请求
response = httpClient.execute(httpGet);
// 从响应模型中获取响应实体
HttpEntity responseEntity = response.getEntity();
System.out.println("响应状态为:" + response.getStatusLine());
if (responseEntity != null) {
System.out.println("响应内容长度为:" + responseEntity.getContentLength());
result=EntityUtils.toString(responseEntity);
System.out.println("响应内容为:" + result);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
// 释放资源
if (httpClient != null) {
httpClient.close();
}
if (response != null) {
response.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
}
2.提供者
@RequestMapping("/get/youparam1")
public String doGetYouParam(String name,Integer age){
return "原来"+name+"都"+age+"岁";
}3.调用
2.3 get有参数：使用URI获得HttpGet
1.消费者
@RequestMapping("/hc/get/youcan2")
public String yooucan2() {
// 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
// 参数
URI uri = null;
try {
// 将参数放入键值对类NameValuePair中,再放入集合中
List params = new ArrayList<>();
params.add(new BasicNameValuePair("name", "lisi"));
params.add(new BasicNameValuePair("age", "18"));
// 设置uri信息,并将参数集合放入uri;
// 注:这里也支持一个键值对一个键值对地往里面放setParameter(String key, String value)
uri = new URIBuilder().setScheme("http").setHost("localhost")
.setPort(8082).setPath("/get/youparam2")
.setParameters(params).build();
} catch (URISyntaxException e1) {
e1.printStackTrace();
}
// 创建Get请求
HttpGet httpGet = new HttpGet(uri);
// 响应模型
CloseableHttpResponse response = null;
String result="";
try {
// 配置信息
RequestConfig requestConfig = RequestConfig.custom()
// 设置连接超时时间(单位毫秒)
.setConnectTimeout(5000)
// 设置请求超时时间(单位毫秒)
.setConnectionRequestTimeout(5000)
// socket读写超时时间(单位毫秒)
.setSocketTimeout(5000)
// 设置是否允许重定向(默认为true)
.setRedirectsEnabled(true).build();
// 将上面的配置信息 运用到这个Get请求里
httpGet.setConfig(requestConfig);
// 由客户端执行(发送)Get请求
response = httpClient.execute(httpGet);
// 从响应模型中获取响应实体
HttpEntity responseEntity = response.getEntity();
System.out.println("响应状态为:" + response.getStatusLine());
if (responseEntity != null) {
System.out.println("响应内容长度为:" + responseEntity.getContentLength());
result=EntityUtils.toString(responseEntity);
System.out.println("响应内容为:" + result);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
// 释放资源
if (httpClient != null) {
httpClient.close();
}
if (response != null) {
response.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
} 2.提供者
@RequestMapping("/get/youparam2")
public String doGetYouParam2(String name,Integer age){
return "原来"+name+"都"+age+"岁";
}3.调试
三 实操实例Post方式
3.1 post无参案例
1.生产者
@RequestMapping("/hc/post/wucan")
public String doPostTestOne() {
// 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
// 创建Post请求
HttpPost httpPost = new HttpPost("http://localhost:8082/post/noparam");
// 响应模型
CloseableHttpResponse response = null;
String result="";
try {
// 由客户端执行(发送)Post请求
response = httpClient.execute(httpPost);
// 从响应模型中获取响应实体
HttpEntity responseEntity = response.getEntity();
System.out.println("响应状态为:" + response.getStatusLine());
if (responseEntity != null) {
System.out.println("响应内容长度为:" + responseEntity.getContentLength());
result=EntityUtils.toString(responseEntity);
System.out.println("响应内容为:" + result);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
// 释放资源
if (httpClient != null) {
httpClient.close();
}
if (response != null) {
response.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
}2.消费者
@RequestMapping("/post/noparam")
public String doPostNoParam(){
return "post 请求无参数 123!";
}3.调用
3.2 post有参案例
1.消费者
@RequestMapping("/hc/post/youcan1")
public String doPostTestFour() {
// 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
// 参数
StringBuffer params = new StringBuffer();
try {
// 字符数据最好encoding以下;这样一来，某些特殊字符才能传过去(如:某人的名字就是“&”,不encoding的话,传不过去)
params.append("name=" + URLEncoder.encode("zhangsan", "utf-8"));
params.append("&");
params.append("age=24");
} catch (UnsupportedEncodingException e1) {
e1.printStackTrace();
}
// 创建Post请求
HttpPost httpPost = new HttpPost("http://localhost:8082//post/youparam1" + "?" + params);
// 设置ContentType(注:如果只是传普通参数的话,ContentType不一定非要用application/json)
httpPost.setHeader("Content-Type", "application/json;charset=utf8");
// 响应模型
CloseableHttpResponse response = null;
String result="";
try {
// 由客户端执行(发送)Post请求
response = httpClient.execute(httpPost);
// 从响应模型中获取响应实体
HttpEntity responseEntity = response.getEntity();
System.out.println("响应状态为:" + response.getStatusLine());
if (responseEntity != null) {
System.out.println("响应内容长度为:" + responseEntity.getContentLength());
result=EntityUtils.toString(responseEntity);
System.out.println("响应内容为:" + result);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
// 释放资源
if (httpClient != null) {
httpClient.close();
}
if (response != null) {
response.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
}2.消费者
@RequestMapping(value="/post/youparam1",method = RequestMethod.POST)
public String doPostYouParam(String name,Integer age){
return "原来"+name+"都"+age+"岁";
}3.调用
3.3 post有参案例2 通过对象映射
1.消费者
@RequestMapping("/hc/post/youcan2")
public String doPostTestTwo() {
// 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
// 创建Post请求
HttpPost httpPost = new HttpPost("http://localhost:8082/post/youparam2");
User user = new User();
user.setName("潘晓婷");
user.setAge(18);
user.setGender("女");
user.setMotto("姿势要优雅~");
// 我这里利用阿里的fastjson，将Object转换为json字符串;
// (需要导入com.alibaba.fastjson.JSON包)
String jsonString = JSON.toJSONString(user);
StringEntity entity = new StringEntity(jsonString, "UTF-8");
// post请求是将参数放在请求体里面传过去的;这里将entity放入post请求体中
httpPost.setEntity(entity);
httpPost.setHeader("Content-Type", "application/json;charset=utf8");
// 响应模型
CloseableHttpResponse response = null;
String result="";
try {
// 由客户端执行(发送)Post请求
response = httpClient.execute(httpPost);
// 从响应模型中获取响应实体
HttpEntity responseEntity = response.getEntity();
System.out.println("响应状态为:" + response.getStatusLine());
if (responseEntity != null) {
System.out.println("响应内容长度为:" + responseEntity.getContentLength());
result=EntityUtils.toString(responseEntity);
System.out.println("响应内容为:" + result);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
// 释放资源
if (httpClient != null) {
httpClient.close();
}
if (response != null) {
response.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
}2.请求者
@RequestMapping(value="/post/youparam2",method = RequestMethod.POST)
public String doPostYouParam(@RequestBody User u){
return u.toString();
}3.调用
3.4 post有参案例3 通过对象映射+参数
1.消费者
@RequestMapping("/hc/post/youcan3")
public String doPostTestThree() {
// 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
// 创建Post请求
// 参数
URI uri = null;
try {
// 将参数放入键值对类NameValuePair中,再放入集合中
List params = new ArrayList<>();
params.add(new BasicNameValuePair("flag", "4"));
params.add(new BasicNameValuePair("meaning", "这是什么鬼？"));
// 设置uri信息,并将参数集合放入uri;
// 注:这里也支持一个键值对一个键值对地往里面放setParameter(String key, String value)
uri = new URIBuilder().setScheme("http").setHost("localhost").setPort(8082)
.setPath("/post/youparam3").setParameters(params).build();
} catch (URISyntaxException e1) {
e1.printStackTrace();
}
HttpPost httpPost = new HttpPost(uri);
// HttpPost httpPost = new
// HttpPost("http://localhost:12345/doPostControllerThree1");
// 创建user参数
User user = new User();
user.setName("潘晓婷");
user.setAge(18);
user.setGender("女");
user.setMotto("姿势要优雅~");
// 将user对象转换为json字符串，并放入entity中
StringEntity entity = new StringEntity(JSON.toJSONString(user), "UTF-8");
// post请求是将参数放在请求体里面传过去的;这里将entity放入post请求体中
httpPost.setEntity(entity);
httpPost.setHeader("Content-Type", "application/json;charset=utf8");
// 响应模型
CloseableHttpResponse response = null;
String result="";
try {
// 由客户端执行(发送)Post请求
response = httpClient.execute(httpPost);
// 从响应模型中获取响应实体
HttpEntity responseEntity = response.getEntity();
System.out.println("响应状态为:" + response.getStatusLine());
if (responseEntity != null) {
System.out.println("响应内容长度为:" + responseEntity.getContentLength());
result=EntityUtils.toString(responseEntity);
System.out.println("响应内容为:" + result);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
// 释放资源
if (httpClient != null) {
httpClient.close();
}
if (response != null) {
response.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
}
2.生产者
@RequestMapping(value="/post/youparam3",method = RequestMethod.POST)
public String doPostYouParam(@RequestBody User u,Integer flag,String meaning){
return u.toString()+" flag:"+flag+" meaning:"+meaning;
}3.调用
