介绍
HttpClient是Apache Jakarta Common 下的子项目，可以用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端编程工具包，并且它支持HTTP协议最新的版本和建议。
作用：可以像前端一样对服务端发起请求
maven坐标
XML
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.13</version>
</dependency>如果引入了以下坐标，则已经传递依赖了上述坐标
XML
<dependency>
<groupId>com.aliyun.oss</groupId>
<artifactId>aliyun-sdk-oss</artifactId>
</dependency>核心API
- HttpClient
- HttpClients
- CloseableHttpClient
- HttpGet
- HttpPost
发送请求步骤
- 创建HttpClient对象
- 创建Http请求对象
- 调用HttpClient的execute方法发送请求
入门案例
java
@SpringBootTest
public class HttpClientTest {
/*
* 测试通过httpclient发送GET方式的请求
* */
@Test
public void testGET() throws IOException {
// 创建httpclient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
// 创建请求对象
HttpGet httpGet = new HttpGet("http://localhost:8080/user/shop/status");
// 发送请求，接收响应结果
CloseableHttpResponse response = httpClient.execute(httpGet);
// 获取服务端返回的状态码
int statusCode = response.getStatusLine().getStatusCode();
System.out.println("服务端返回的状态码为："+statusCode);
HttpEntity entity = response.getEntity();
String body = EntityUtils.toString(entity);
System.out.println("服务端返回的数据为："+body);
// 关闭资源
response.close();
httpClient.close();
}
/*
* 测试通过httpclient发送POST方式的请求
* */
@Test
public void testPOST() throws IOException {
// 创建httpclient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
// 创建请求对象
HttpPost httpPost = new HttpPost("http://localhost:8080/admin/employee/login");
JSONObject jsonObject = new JSONObject();
jsonObject.put("username","admin");
jsonObject.put("password","123456");
StringEntity entity = new StringEntity(jsonObject.toString());
// 指定请求编码方式
entity.setContentEncoding("utf-8");
// 指定数据格式
entity.setContentType("application/json");
httpPost.setEntity(entity);
// 发送请求
CloseableHttpResponse response = httpClient.execute(httpPost);
// 解析返回结果
int statusCode = response.getStatusLine().getStatusCode();
System.out.println("服务端返回的状态码为："+statusCode);
HttpEntity entity1 = response.getEntity();
String body = EntityUtils.toString(entity1);
System.out.println("服务端返回的数据为："+body);
// 关闭资源
response.close();
httpClient.close();
}
}工具类
java
/**
* Http工具类
*/
public class HttpClientUtil {
static final int TIMEOUT_MSEC = 5 * 1000;
/**
* 发送GET方式请求
* @param url
* @param paramMap
* @return
*/
public static String doGet(String url,Map<String,String> paramMap){
// 创建Httpclient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
String result = "";
CloseableHttpResponse response = null;
try{
URIBuilder builder = new URIBuilder(url);
if(paramMap != null){
for (String key : paramMap.keySet()) {
builder.addParameter(key,paramMap.get(key));
}
}
URI uri = builder.build();
//创建GET请求
HttpGet httpGet = new HttpGet(uri);
//发送请求
response = httpClient.execute(httpGet);
//判断响应状态
if(response.getStatusLine().getStatusCode() == 200){
result = EntityUtils.toString(response.getEntity(),"UTF-8");
}
}catch (Exception e){
e.printStackTrace();
}finally {
try {
response.close();
httpClient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
}
/**
* 发送POST方式请求
* @param url
* @param paramMap
* @return
* @throws IOException
*/
public static String doPost(String url, Map<String, String> paramMap) throws IOException {
// 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);
// 创建参数列表
if (paramMap != null) {
List<NameValuePair> paramList = new ArrayList();
for (Map.Entry<String, String> param : paramMap.entrySet()) {
paramList.add(new BasicNameValuePair(param.getKey(), param.getValue()));
}
// 模拟表单
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList);
httpPost.setEntity(entity);
}
httpPost.setConfig(builderRequestConfig());
// 执行http请求
response = httpClient.execute(httpPost);
resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
} catch (Exception e) {
throw e;
} finally {
try {
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return resultString;
}
/**
* 发送POST方式请求
* @param url
* @param paramMap
* @return
* @throws IOException
*/
public static String doPost4Json(String url, Map<String, String> paramMap) throws IOException {
// 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);
if (paramMap != null) {
//构造json格式数据
JSONObject jsonObject = new JSONObject();
for (Map.Entry<String, String> param : paramMap.entrySet()) {
jsonObject.put(param.getKey(),param.getValue());
}
StringEntity entity = new StringEntity(jsonObject.toString(),"utf-8");
//设置请求编码
entity.setContentEncoding("utf-8");
//设置数据类型
entity.setContentType("application/json");
httpPost.setEntity(entity);
}
httpPost.setConfig(builderRequestConfig());
// 执行http请求
response = httpClient.execute(httpPost);
resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
} catch (Exception e) {
throw e;
} finally {
try {
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return resultString;
}
private static RequestConfig builderRequestConfig() {
return RequestConfig.custom()
.setConnectTimeout(TIMEOUT_MSEC)
.setConnectionRequestTimeout(TIMEOUT_MSEC)
.setSocketTimeout(TIMEOUT_MSEC).build();
}
}小程序微信登录
官方说明：开放能力 / 用户信息 / 小程序登录
步骤1：配置好用户端生成令牌所需配置和调用 auth.code2Session 接口的所需参数的前两项（appid和secret）
sky:
jwt:
# 设置jwt签名加密时使用的秘钥
user-secret-key: itcast
# 设置jwt过期时间
user-ttl: 7200000
# 设置前端传递过来的请求体中的令牌名称
user-token-name: authentication
wechat:
appid: ${sky.wechat.appid}
secret: ${sky.wechat.secret}注意：
user-secret-key 和 user-ttl 可以自定义
user-token-name 需要与前端沟通决定
wechat 中的配置需要改为自己的
步骤2：代码开发
Controller
java
@RestController
@RequestMapping("/user/user")
@Api(tags = "C端用户接口")
@Slf4j
public class UserController {
@Autowired
private UserService userService;
@Autowired
private JwtProperties jwtProperties;
/**
* 微信登录
* @param userLoginDTO
* @return
*/
@PostMapping("/login")
@ApiOperation("微信登录")
public Result<UserLoginVO> login(@RequestBody UserLoginDTO userLoginDTO){
log.info("微信登录：{}", userLoginDTO.getCode());
// 调用service完成微信登录
User user = userService.wxLogin(userLoginDTO);
//为微信用户生成jwt令牌
Map<String, Object> claims=new HashMap<>();
claims.put(JwtClaimsConstant.USER_ID, user.getId());
String token = JwtUtil.createJWT(jwtProperties.getUserSecretKey(), jwtProperties.getUserTtl(), claims);
UserLoginVO userLoginVO = UserLoginVO.builder()
.id(user.getId())
.openid(user.getOpenid())
.token(token)
.build();
return Result.success(userLoginVO);
}
}Service实现类
java
@Service
public class UserServiceImpl implements UserService {
//微信服务接口地址
public static final String WX_LOGIN_URL = "https://api.weixin.qq.com/sns/jscode2session";
@Autowired
private WeChatProperties weChatProperties;
@Autowired
private UserMapper userMapper;
/**
* 微信登录
* @param userLoginDTO
* @return
*/
@Override
public User wxLogin(UserLoginDTO userLoginDTO) {
//调用微信接口服务，获取当前微信用户的openid
String openid = getOpenid(userLoginDTO.getCode());
//判断openid是否为空，如果为空表示登录失败，抛出业务异常
if (openid == null)
throw new LoginFailedException(MessageConstant.LOGIN_FAILED);
//根据openid查询当前用户是否为新用户
User user = userMapper.getByOpenid(openid);
//如果是新用户，自动完成注册
if (user == null) {
user = User.builder()
.openid(openid)
.createTime(LocalDateTime.now())
.build();
userMapper.insert(user);
}
//返回用户对象
return user;
}
/**
* 调用微信接口服务，获取当前微信用户的openid
* @param code
* @return
*/
private String getOpenid(String code) {
//调用微信接口服务，获取当前微信用户的openid
Map<String, String> map=new HashMap<>();
map.put("appid", weChatProperties.getAppid());
map.put("secret", weChatProperties.getSecret());
map.put("js_code", code);
map.put("grant_type", "authorization_code");
String json = HttpClientUtil.doGet(WX_LOGIN_URL, map);
JSONObject jsonObject = JSON.parseObject(json);
return jsonObject.getString("openid");
}
}