HttpClients.createDefault()；HttpGet(String url)创建HttpGet对象即可；URIBuilder(String url)创建对象，再调用addParameter(Stringparam, String value)`， 或setParameter(String param, String）execute(HttpUriRequestHttpResponse的getAllHeaders()、getHeaders(StringHttpResponse的getEntity()方法可获取HttpEntity对象，该对象包装了服务器的响应内容。程序可通过该对象获取服务器的响应内容。通过调用getStatusLine().getStatusCode()可以获取响应状态码。构建一个Maven项目，引入如下依赖
<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.8</version>
</dependency>
如果是无参数的GET请求，则直接使用构造方法HttpGet(String url)创建HttpGet对象即可
/**
*普通的GET请求
*/
public class DoGET {
public static void main(String[] args) throws Exception {
// 创建Httpclient对象
CloseableHttpClient httpclient = HttpClients.createDefault();
// 创建http GET请求
HttpGet httpGet = new HttpGet("http://www.baidu.com");
CloseableHttpResponse response = null;
try {
// 执行请求
response = httpclient.execute(httpGet);
// 判断返回状态是否为200
if (response.getStatusLine().getStatusCode() == 200) {
//请求体内容
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
//内容写入文件
FileUtils.writeStringToFile(new File("E:\\devtest\\baidu.html"), content, "UTF-8");
System.out.println("内容长度："+content.length());
}
} finally {
if (response != null) {
response.close();
}
//相当于关闭浏览器
httpclient.close();
}
}
}
如果是带参数GET请求，则可以先使用URIBuilder(String url)创建对象，再调用addParameter(Stringparam, String value)
public class HttpclientTest {
@Test
public void httpGet() throws IOException {
// 1.创建httpclient
CloseableHttpClient httpClient = HttpClients.createDefault();
//2. 创建HttpGet，设置URL访问地址
String urlTest = "https://XXXX/XXX/shopping/platformInfo?platformid=7";
HttpGet httpGet = new HttpGet(urlTest);
// 3. 请求执行，获取响应
CloseableHttpResponse response = httpClient.execute(httpGet);
//解析响应
if (response.getStatusLine().getStatusCode() == 2000) {
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content.length());
}
// 4.获取响应实体
HttpEntity entity = response.getEntity();
System.out.println(EntityUtils.toString(entity, "utf-8"));
response.close();
httpClient.close();
}
代码中使用的是公司接口，请求URL前缀就XXX表示了，get请求如图所示
运行结果：我们已经看到get接口成功返回一条数据
HttpClients.createDefault()；
execute(HttpUriRequestHttpResponse的getEntity()方法可获取HttpEntity对象，该对象包装了服务器的响应内容。程序可通过该对象获取服务器的响应内容。通过调用getStatusLine().getStatusCode()可以获取响应状态码。如果是带JSON参数POST请求，先构建HttpEntity对象并设置请求参数，因为我们的参数是JSON格式的，需要将请求对象转换成string类型的，然后调用setEntity(HttpEntityentity)创建HttpPost对象
首先我们先创建一个请求实体类PostData，代码如图所示
/**
* @param
* @author wcy
* @create 2022/10/15
* @return
* @description
**/
public class PostData {
private String categoryid;
private int currentPage;
private String end_time;
private int pageSize;
private int platformid;
private String start_time;
private int step_id;
public String getCategoryid() {
return categoryid;
}
public void setCategoryid(String categoryid) {
this.categoryid = categoryid;
}
public int getCurrentPage() {
return currentPage;
}
public void setCurrentPage(int currentPage) {
this.currentPage = currentPage;
}
public String getEnd_time() {
return end_time;
}
public void setEnd_time(String end_time) {
this.end_time = end_time;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public int getPlatformid() {
return platformid;
}
public void setPlatformid(int platformid) {
this.platformid = platformid;
}
public String getStart_time() {
return start_time;
}
public void setStart_time(String start_time) {
this.start_time = start_time;
}
public int getStep_id() {
return step_id;
}
public void setStep_id(int step_id) {
this.step_id = step_id;
}
}
@Test
public void httpPost() throws IOException {
// 1.创建httpclient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
// 2.创建post对象，设置URL访问地址
String url = "https://XxX/XxX/shopping/goodsRank";
HttpPost httpPost = new HttpPost(url);
CloseableHttpResponse response = null;
try {
PostData data = new PostData();
data.setCategoryid("");
data.setCurrentPage(1);
data.setEnd_time("2022-11-02");
data.setPageSize(20);
data.setPlatformid(1);
data.setStart_time("2022-11-02");
data.setStep_id(464);
String bodyEntity = JSON.toJSONString(data);
HttpEntity entity = new StringEntity(bodyEntity, ContentType.APPLICATION_JSON);
httpPost.setEntity(entity);
//发送post请求
response = httpClient.execute(httpPost);
//解析响应
if (response.getStatusLine().getStatusCode() == 200) {
//获取响应数据
entity = response.getEntity();
System.out.println(EntityUtils.toString(entity, "utf-8"));
}
}catch (IOException e){
e.printStackTrace();
}
}
运行结果：
post请求传递参数的形式是将参数放入表单请求体中，然后将表单对象放入请求体中传递。
//1.获得一个httpclient对象
CloseableHttpClient httpclient = HttpClients.createDefault();
//2.生成一个post请求
HttpPost httpPost = new HttpPost("http://www.baidu.com/");
//3.请求参数添加到请求体中，表单提交
List<NameValuePair> nvpList = new ArrayList<NameValuePair>();
nvps.add(new BasicNameValuePair(key, val));
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(nvps, charset);
httpPost.setEntity(formEntity);
//4.执行get请求并返回结果
CloseableHttpResponse response = httpclient.execute(httpPost);
try {
//5.处理结果响应体
HttpEntity entity = response.getEntity();
} finally {
response.close();
}
首先在postman编写好post请求的URL，请求参数，请求方式，请求头
点击sends按钮右侧的code弹窗展示，如图所示
框里面的代码就是自动生成的，我们可以复制代码到idea中，需要在maven`装下OKhhtp的依赖
官网连接：https://mvnrepository.com/
OkHttpClient client = new OkHttpClient().newBuilder()
.build();
MediaType mediaType = MediaType.parse("text/plain");
RequestBody body = new MultipartBody.Builder().setType(MultipartBody.FORM)
.addFormDataPart("categoryid","")
.addFormDataPart("currentPage","1")
.addFormDataPart("end_time ","2022-11-01")
.addFormDataPart("pageSize","20")
.addFormDataPart("platformid ","1")
.addFormDataPart("start_time ","2022-11-01")
.addFormDataPart("step_id ","464")
.build();
Request request = new Request.Builder()
.url("https://XXX/XXX/shopping/goodsRank")
.method("POST", body)
.addHeader("Cookie", "laravel_session=eyJpdiI6IkRxcWx6M201UHRWMWFWeDY3b0RURmc9PSIsInZhbHVlIjoid0pSM241cmgvRUk5WndHTnc2azlzNFpHVDh6MCt5R1pSV21pQXRPRDB1eEpyMThNZVUrelRKYzJHSVUzNHp3T290RHppOVNvSFZ3Z2VCQ2g4SEFQUjBXSGpRL3VkcUJiRUFzRGc5b21BRnhOUUwzUkNENlhzUEJlVGtWZkhZNGoiLCJtYWMiOiIyYzM1NDhkYzQ0YmZiNjQ5OWIwZjg1NDA3NTYxZTcyM2IyODAxNWI1ZGU4NmEzOTE2YjRmOTBjYzQzMzUyNjY1In0%3D")
.build();
Response response = client.newCall(request).execute();
System.out.println(response);
}
OKhttp的语法跟httpclient差不多，都是http工具类