java.lang.IllegalStateException : Already connected at setDoOutput 错误

Question

我在尝试使用 HttpsURLConnection API 运行以执行 HTTPS GET 请求时遇到 java.lang.IllegalStateException: Already connected 异常>.

请在下面找到代码:

HttpsURLConnection con = null;

    try {
        URL obj = new URL(url);
        con = (HttpsURLConnection) obj.openConnection();

        con.setRequestMethod("GET");
        con.setRequestProperty("Authorization", header);
        con.setRequestProperty ("Content-Type", "application/x-www-form-urlencoded");
        String urlParameters = "schema=1.0&form=json&byBillingAccountId={EQUALS,cesar@abc.org}";

        con.setDoOutput(true);

        DataOutputStream wr = new DataOutputStream(con.getOutputStream());
        wr.writeBytes(urlParameters);
        wr.flush();
        wr.close();

        int responseCode = con.getResponseCode();

        System.out.println("Response Code = " + responseCode);

        BufferedReader in = new BufferedReader(
                new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();
        con.disconnect();
        //print result
        System.out.println("Response = " + response.toString());


    } catch (MalformedURLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if(con!=null) con.disconnect();
    }

不确定我为什么会这样。

知道如何解决这个问题吗？

堆栈跟踪

java.lang.IllegalStateException: Already connected
at java.net.URLConnection.setDoOutput(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.setDoOutput(Unknown Source)
at com.comcast.ccp.xbo.testing.partnerdevices.AppTest.testReadProperties(AppTest.java:65)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:84)
at org.testng.internal.MethodInvocationHelper$1.runTestMethod(MethodInvocationHelper.java:200)
at org.springframework.test.context.testng.AbstractTestNGSpringContextTests.run(AbstractTestNGSpringContextTests.java:155)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.testng.internal.MethodInvocationHelper.invokeHookable(MethodInvocationHelper.java:212)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:707)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
at org.testng.TestRunner.privateRun(TestRunner.java:767)
at org.testng.TestRunner.run(TestRunner.java:617)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:334)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:329)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:291)
at org.testng.SuiteRunner.run(SuiteRunner.java:240)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1224)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1149)
at org.testng.TestNG.run(TestNG.java:1057)
at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:111)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:204)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:175)

Answer 1

根据 this question setDoOutput 用于 PUT 和 POST 请求(它们包含请求实体主体)。所以跟你手动设置的请求方法GET有冲突。

您正在使用 GET，因此应像 this question 中那样设置 url 参数并且您可以删除 setDoOutput。

此外 Content-Type 对 GET 请求没有意义 ( source )