远程调用Httpclient

1.HttpClient

引入依赖

<dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
</dependency>

使用httpClent需要引入httpClent依赖

如果使用了Eureka分布式架构,Eurka的依赖中包含了HttpClient,不需要额外引入了

 <dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

2.GET

CloseableHttpClient httpClient = HttpClients.createDefault();
CloseableHttpClient httpClient2 = HttpClientBuilder.create().build();

Closeable是接口HttpClient的实现类,两种写法都可以创建CloseableHttpClient.

1. httpClents.createDefault()方法内部其实也是使用了第二种方法,所以两种写法创建CloseableHttpclent的方式是一样的

   public static CloseableHttpClient createDefault() {
       return HttpClientBuilder.create().build();
   }
   

2. 生成URL

		//创建url 方法一 使用URIBuilder
        String url = "http://localhost:8080/getClientUrl";
        URI uri = null;
        try {
            uri = new URIBuilder(url).setParameter("param1", "params1")
                    .setParameter("param2", "param2").build();
        } catch (URISyntaxException e) {
            e.printStackTrace();
        }
        //创建url方法二 拼接
		String url = "http://localhost:8080/getClientUrl";
        StringBuffer params = new StringBuffer();
        //请求参数文需要进行URLEncoder编码 gbk/utf8
        params.append("param1=param1");
        params.append("&");
        params.append("param2=param2");
        HttpGet httpGet = new HttpGet(url+"?"+params);
        //设置param方法三
        List<NameValuePair> params = new ArrayList<>();
			params.add(new BasicNameValuePair("param1", "param1"));
			params.add(new BasicNameValuePair("param2", "param2"));
			// 设置uri信息,并将参数集合放入uri;
			uri = new URIBuilder(url).setParameters(params).build();

3.通过构造方法创建HttpGet,参数位uri

HttpGet httpGet = new HttpGet(uri);

3.5 设置配置信息

// 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);
        
//请求头
httpGet.addHeader("Content-Type","application/json");

4.获取response

		//定义response
        CloseableHttpResponse response = null;
        try {
            response = httpClient.execute(httpGet);
            HttpEntity entity = response.getEntity();
            //设值编码格式
            String result = EntityUtils.toString(entity, "utf-8");
            System.out.println(result);
        } catch (IOException e) {
            e.printStackTrace();
        }

3.使用JSONObject以json格式发送POST请求

@Test
    public void HttpClientPost(){
        CloseableHttpClient client = HttpClients.createDefault();
        String url = "http://localhost:8080/httpClentPost";
        HttpPost httpPost = new HttpPost(url);

        JSONObject jsonObject = new JSONObject();
        StringEntity stringEntity = null;
        try {
            jsonObject.put("id", "11");
            jsonObject.put("name","小王");
            jsonObject.put("age","99");
            stringEntity = new StringEntity(jsonObject.toString(),"utf-8");
        } catch (JSONException e) {
            e.printStackTrace();
        }
        httpPost.setEntity(stringEntity);
        httpPost.setHeader("Content-type","application/json;charset=utf-8");

        CloseableHttpResponse  response = null;
        try {
            response = client.execute(httpPost);
            HttpEntity entity = response.getEntity();
            System.out.println(EntityUtils.toString(entity,"utf-8"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

不使用JSONObject

		StringEntity stringEntity = null;

        User user = new User();
        user.setId("11");
        user.setAge(99);
        user.setName("小王");
        stringEntity = new StringEntity(JSON.toJSONString(user),"utf-8");

抽象类AbstractHttpEntity implements HttpEntity

StringEntity extends AbstractHttpEntity

UrlEncodeFormEntity 继承 StringEntity

使用UrlEncodeFormEntity来发送x-www-form-urlencoded

 @Test
    public void HttpClientPostUrlEncodedForm(){
        CloseableHttpClient client = HttpClients.createDefault();
        String url = "http://localhost:8080/httpClentPost";
        HttpPost httpPost = new HttpPost(url);

        ArrayList<NameValuePair> nameValuePairs = new ArrayList<>();
        nameValuePairs.add(new BasicNameValuePair("param1","param1"));
        nameValuePairs.add(new BasicNameValuePair("param2","param2"));
        UrlEncodedFormEntity formEntity = null;
        try {
            formEntity = new UrlEncodedFormEntity(nameValuePairs,"utf-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

        httpPost.setEntity(formEntity);
        httpPost.setHeader("Content-type","application/x-www-form-urlencoded;charset=utf-8");

        CloseableHttpResponse  response = null;
        try {
            response = client.execute(httpPost);
            HttpEntity entity = response.getEntity();
            System.out.println(EntityUtils.toString(entity,"utf-8"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

远程调用Httpclient