前言
在工作中可能存在要去调用其他项目的接口，这篇文章我们实现在Java代码中实现调用其他项目的接口。
本章内容：
创建一个携带参数的POST请求，去请求其他项目的接口并返回数据。附加HTTP请求工具类，包含（GET、POST、无参GET、无参POST）
准备
导入pom依赖
<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpcore -->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
</dependency>
<!--json工具-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.76</version>
</dependency>
案例
创建一个携带参数的POST请求
public static String doPost(String url, String str, String encoding) {
String body = "";
try {
// 创建httpclient对象
CloseableHttpClient client = HttpClients.createDefault();
// 创建post方式请求对象
HttpPost httpPost = new HttpPost(url);
// 设置参数到请求对象中
httpPost.setEntity(new StringEntity(str, encoding));
// 设置header信息
// 指定报文头【Content-type】、【User-Agent】
httpPost.setHeader("Content-type", "application/json;charset=UTF-8");
// 执行请求操作，并拿到结果（同步阻塞）
CloseableHttpResponse response = client.execute(httpPost);
// 获取结果实体
HttpEntity entity = response.getEntity();
if (entity != null) {
// 按指定编码转换结果实体为String类型
body = EntityUtils.toString(entity, encoding);
}
EntityUtils.consume(entity);
// 释放链接
response.close();
return body;
} catch (Exception e1) {
e1.printStackTrace();
return "";
}
}
参数列表：
-
url：请求的接口地址（例：http://IP地址:8080/user/login） -
str：发送请求时候携带的参数（必须为JSON格式的字符串） -
encoding：编码字符集（一般都为UTF-8）
通过调用doPost()可以接受一个返回值，返回值的类型是String类型的JSON字符串，通过fastjson工具进行转换在进行其他业务操作。文章来源：https://www.toymoban.com/news/detail-519611.html
测试
JSONObject json= new JSONObject();
json.put("id", "10010");
json.put("name", "蔡徐坤");
String url = "http://IP地址:8080/user/login";
String encoding = "UTF-8";
String result = doPost(url, json.toString(), encoding);
logger.info("请求地址返回的数据为 = {}", result);
返回结果：文章来源地址https://www.toymoban.com/news/detail-519611.html
{code : 500, msg: "登录失败"}
完整的HTTP请求工具类
public class HttpClientUtil {
/**
* 带参数的get请求
* @param url
* @param param
* @return String
*/
public static String doGet(String url, Map<String, String> param) {
// 创建Httpclient对象
if(url==null||"".equals(url))
return null;
CloseableHttpClient httpclient = HttpClients.createDefault();
String resultString = "";
CloseableHttpResponse response = null;
try {
// 创建uri
URIBuilder builder = new URIBuilder(url);
if (param != null) {
for (String key : param.keySet()) {
builder.addParameter(key, param.get(key));
}
}
URI uri = builder.build();
// 创建http GET请求
HttpGet httpGet = new HttpGet(uri);
// 执行请求
response = httpclient.execute(httpGet);
// 判断返回状态是否为200
if (response.getStatusLine().getStatusCode() == 200) {
resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (response != null) {
response.close();
}
httpclient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return resultString;
}
/**
* 不带参数的get请求
* @param url
* @return String
*/
public static String doGet(String url) {
return doGet(url, null);
}
public static String doGetByHeader(String url, String orgKey) {
// 创建Httpclient对象
if(url==null||"".equals(url))
return null;
CloseableHttpClient httpclient = HttpClients.createDefault();
String resultString = "";
CloseableHttpResponse response = null;
try {
// 创建uri
URIBuilder builder = new URIBuilder(url);
URI uri = builder.build();
// 创建http GET请求
HttpGet httpGet = new HttpGet(uri);
httpGet.addHeader("Org-Key", orgKey);
// 执行请求
response = httpclient.execute(httpGet);
// 判断返回状态是否为200
if (response.getStatusLine().getStatusCode() == 200) {
resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (response != null) {
response.close();
}
httpclient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return resultString;
}
/**
* 带参数的post请求
* @param url
* @param param
* @return String
*/
public static String doPost(String url, Map<String, String> param) {
// 创建Httpclient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
CloseableHttpResponse response = null;
String resultString = "";
try {
// 创建Http Post请求
HttpPost httpPost = new HttpPost(url);
httpPost.addHeader("Content-Type","application/json; charset=utf-8");
httpPost.addHeader("X-Api-Sign-Version","2.0.0");
// 创建参数列表
if (param != null) {
List<NameValuePair> paramList = new ArrayList<>();
for (String key : param.keySet()) {
paramList.add(new BasicNameValuePair(key, param.get(key)));
}
// 模拟表单
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList);
httpPost.setEntity(entity);
// httpPost.setEntity(new UrlEncodedFormEntity(nvps, encoding));
// httpPost.setEntity(new StringEntity(str, encoding));
}
// 执行http请求
response = httpClient.execute(httpPost);
resultString = EntityUtils.toString(response.getEntity(), "utf-8");
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return resultString;
}
/**
* 不带参数的post请求
* @param url
* @return String
*/
public static String doPost(String url) {
return doPost(url, null);
}
/**
* 传送json类型的post请求
* @param url
* @param json
* @return String
*/
public static String doPostJson(String url, String json, String token) {
// 创建Httpclient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
CloseableHttpResponse response = null;
String resultString = "";
try {
if(url.contains("?")){
url = url + "&access_token=" + token;
} else {
url = url + "?access_token=" + token;
}
// 创建Http Post请求
HttpPost httpPost = new HttpPost(url);
//httpPost.addHeader("Org-Key", orgKey);
// 创建请求内容
StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);
httpPost.setEntity(entity);
// 执行http请求
response = httpClient.execute(httpPost);
resultString = EntityUtils.toString(response.getEntity(), "utf-8");
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return resultString;
}
}
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