http发送post请求报400，405 报错如下：
发送 POST 请求出现异常！java.io.IOException: Server returned HTTP response code: 400 for URL: http://111.123.138.247:8080/jobScheduler/pendingJobjava.io.IOException: Server returned HTTP response code: 400 for URL: http://111.123.138.247:8083/jobScheduler/pendingJob at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1627) at com.ulearning.ulms.util.HttpClientUtil.sendPost(HttpClientUtil.java:233) at com.ulearning.ulms.homework.action.TutorHomeworkAction.pushMessage(TutorHomeworkAction.java:799) at com.ulearning.ulms.homework.action.TutorHomeworkAction.saveOrUpdateHomework(TutorHomeworkAction.java:742) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:280) at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:216) at com.ulearning.ulms.homework.action.TutorHomeworkAction.execute(TutorHomeworkAction.java:142) at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484) at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274) at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1480) at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:524) at javax.servlet.http.HttpServlet.service(HttpServlet.java:646) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at com.ulearning.ulms.core.filter.JSPSupportFilter.doFilter(JSPSupportFilter.java:51) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at com.ulearning.ulms.util.RolePermissionFilter.doFilter(RolePermissionFilter.java:72) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at com.ulearning.ulms.util.XssFilter.doFilter(XssFilter.java:23) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at com.ulearning.ulms.util.BehaviorRecordsFilter.doFilter(BehaviorRecordsFilter.java:84) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at com.ulearning.ulms.util.i18n.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:103) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
解决方法：400报错，可以确定的是传入参数有问题，所以要从传参这查起
错误一： 参数时间格式是"yyyy-MM-dd HH:mm:ss"，接收的是"yyyy-MM-dd HH:mm"，导致时间格式和接收方不一样，所以报错，把转换的时间格式改为和需要接受的参数一致即可
com.alibaba.fastjson.JSONObject jsonStr = new com.alibaba.fastjson.JSONObject(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm"); SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); JSONObject jsonStr = new JSONObject(); Date dBefore = new Date(); Calendar calendar = Calendar.getInstance(); //得到日历 calendar.setTime(ah.getEndTime());//把当前时间赋给日历 calendar.add(Calendar.DAY_OF_MONTH, -1); //设置为前一天 dBefore = calendar.getTime(); //得到前一天的时间 String defaultStartDate = sdf.format(dBefore); //格式化前一天 jsonStr.put("pushTime", defaultStartDate ); jsonStr.put("content", "你好"); try { HttpClientUtil.sendPost(url, jsonStr.toString(),null,HttpClientUtil.CONTENTTYPE); } catch (Exception e) { e.printStackTrace(); }
错误二：中文参数乱码问题，导致400错误
public static String sendPost(String url, String param, String contentType) { OutputStreamWriter out = null; BufferedReader in = null; String result = ""; try { URL realUrl = new URL(url); // 打开和URL之间的连接 HttpURLConnection conn = (HttpURLConnection) realUrl.openConnection(); // 设置通用的请求属性 conn.setRequestProperty("accept", "*/*"); conn.setRequestProperty("connection", "Keep-Alive"); conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)"); conn.setRequestProperty("Content-Type", contentType); // 发送POST请求必须设置如下两行 conn.setDoOutput(true); conn.setDoInput(true); /*************************************************************************/ // 获取URLConnection对象对应的输出流 // out = new PrintWriter(conn.getOutputStream()); out = new OutputStreamWriter(conn.getOutputStream(), "utf-8"); // 8859_1 /*************************************************************************/ out.write(param); // post的关键所在 // 发送请求参数 // out.print(param); // flush输出流的缓冲 out.flush(); // 定义BufferedReader输入流来读取URL的响应 int code = conn.getResponseCode(); if(code == 200) { in = new BufferedReader(new InputStreamReader(conn.getInputStream())); }else{ in = new BufferedReader(new InputStreamReader(conn.getErrorStream())); } String line; while ((line = in.readLine()) != null) { result += line; } } catch (Exception e) { System.out.println("发送 POST 请求出现异常！" + e); e.printStackTrace(); } // 使用finally块来关闭输出流、输入流 finally { try { if (out != null) { out.close(); } if (in != null) { in.close(); } } catch (IOException ex) { ex.printStackTrace(); } } return result; }
解决方法：发送post方法 OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream(), "utf-8");
问题三：报405的原因：在post方法中添：conn.setRequestProperty("Content-Type", contentType);
