序言
最近再写 http 请求相关的东西，为了方便就直接通过 java HttpClient 调用另外一个系统。
结果调试了一晚上才通过，血的教训，这里记录一下。
服务端
import com.alibaba.fastjson.JSON;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
/**
* 用户控制层
* @author binbin.hou
*/
@Controller
@RequestMapping("/user")
public class UserController {
private static final Logger logger = LoggerFactory.getLogger(UserController.class);
@RequestMapping(value = "/active", method = RequestMethod.POST)
@ResponseBody
public String active(@RequestBody UserReqVo reqVo) {
try {
logger.info("开始处理信息 {}", reqVo);
if(null == reqVo) {
logger.error("请求参数不可为空，忽略处理");
return "fail";
}
final String traceId = reqVo.getTraceId();
boolean result = xxxx();
logger.info("{} 处理结果 {}", traceId, result);
return "ok";
} catch (Exception exception) {
logger.error("{} 处理异常", reqVo, exception);
return "fail";
}
}
}
这里是非常简单的一个方法定义，然而有很多地方还是要注意下。
@RequestMapping(value = "/active", method = RequestMethod.POST) 指定这是一个 post 请求；@RequestBody 直接将 json 反序列为对象。
请求端
最基本的 get/post 请求工具类：
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
public class HttpUtils {
private static Logger logger = LoggerFactory.getLogger(HttpUtils.class);
public static String doPost(String url, String requestParams) {
StringBuffer sb = new StringBuffer();
try {
logger.info("请求日志 url: {}, 参数：{}", url, requestParams);
URL urlPost = new URL(url);
HttpURLConnection connection = (HttpURLConnection) urlPost.openConnection();
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setRequestMethod("POST");
connection.setUseCaches(false);
connection.setInstanceFollowRedirects(true);
connection.setRequestProperty("Content-Type", "application/json;charset=UTF-8");
connection.setConnectTimeout(45 * 1000);
connection.connect();
if (StringUtils.isNotEmpty(requestParams)) {
DataOutputStream out = new DataOutputStream(connection.getOutputStream());
out.write(requestParams.getBytes("UTF-8"));
out.flush();
out.close();
}
BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String lines;
while ((lines = reader.readLine()) != null) {
String lines1 = new String(lines.getBytes(), "UTF-8");
sb.append(lines1);
}
reader.close();
connection.disconnect();
} catch (Exception e) {
logger.error("请求遇到异常", e);
throw new RuntimeException();
}
logger.info("请求结果: {}", sb.toString());
return sb.toString();
}
/**
* 向指定URL发送GET方法的请求
*/
public static String doGet(String url, String requestParams, String token) {
BufferedReader in = null;
try {
logger.info(url + "?" + requestParams);
URL realUrl = new URL(url + "?" + requestParams);
// 打开和URL之间的连接
URLConnection connection = realUrl.openConnection();
// 设置通用的请求属性
connection.setRequestProperty("accept", "*/*");
connection.setRequestProperty("connection", "Keep-Alive");
connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
connection.setRequestProperty("token", token);
connection.setConnectTimeout(5000);
connection.setReadTimeout(5000);
// 建立实际的连接
connection.connect();
// 定义 BufferedReader输入流来读取URL的响应
in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
StringBuffer sb = new StringBuffer();
String line;
while ((line = in.readLine()) != null) {
sb.append(line);
}
logger.info(sb.toString());
return sb.toString();
} catch (Exception e) {
logger.error("Exception occur when send http get request!", e);
}
// 使用finally块来关闭输入流
finally {
try {
if (in != null) {
in.close();
}
} catch (Exception e2) {
e2.printStackTrace();
}
}
return null;
}
}
这里 post 请求的属性设置很重要：
connection.setRequestProperty("Content-Type", "application/json;charset=UTF-8");
表示传入的参数时 json 类型。
调用方式如下：
String json = JSON.toJSONString(user);
HttpUtils.doPost(url, json);
