增加网络爬虫部分

Author: 0xcaffebabe

README.md

@@ -52,6 +52,7 @@
   - [JPA](./后端开发/JakartaEE/JPA.md)
 </details>
 
+- [网络爬虫](./网络爬虫/nav.md)
 
 #### 前端开发
   - [HTML](./前端开发/HTML.md)

网络爬虫/nav.md

@@ -0,0 +1,32 @@
+>网络爬虫，是一种按照一定的规则，自动地抓取万维网信息的程序或者脚本。另外一些不常使用的名字还有蚂蚁、自动索引、模拟程序或者蠕虫。
+
+# HttpClient
+
+## Get请求
+
+```java
+        HttpGet get = new HttpGet("http://www.baidu.com");
+
+        try (CloseableHttpClient client = HttpClients.createDefault();
+             CloseableHttpResponse response = client.execute(get)) {
+            String s = EntityUtils.toString(response.getEntity(), "utf8");
+
+            System.out.println(s);
+        }
+```
+
+- 设置参数
+
+```java
+URIBuilder uriBuilder = new URIBuilder("http://www.baidu.com/s").addParameter("wd", "关键词");
+HttpGet get = new HttpGet(uriBuilder.build());
+```
+
+## POST请求
+
+```java
+        var request = new HttpPost("http://example");
+        var pairs = List.of(new BasicNameValuePair("keys", "java"), new BasicNameValuePair("keys", "python"));
+        UrlEncodedFormEntity entity = new UrlEncodedFormEntity(pairs, "utf8");
+        request.setEntity(entity);
+```