HttpURLConnection 在 getResponseCode 处抛出 NullPointerException
HttpURLConnection throws NullPointerException at getResponseCode
我的 POST 请求在 getResponseCode() 处抛出一个 NullPointerException，但是，直到今天它都运行良好。等效的 curl 调用可以正常工作，因此问题应该在 Java 中。同样的实现（当然没有一些属性）适用于 GET 请求。这是：
private Object executeRequest(URL url, String httpMethod, String contentType, URL jobPropsPath)
throws NoSuchAlgorithmException, KeyManagementException,
MalformedURLException, IOException, ParseException {
if(contentType == null) {
contentType = "application/json";
}
// curl -k
TrustManager[] trustAllCerts = { new OozieWorkflowTest.CustomX509TrustManager() };
SSLContext sc = SSLContext.getInstance("SSL");
sc.init(null, trustAllCerts, new SecureRandom());
HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
HostnameVerifier allHostsValid = (hostname, session) -> true;
HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);
// execute a request
HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
conn.setRequestProperty("Content-Type", contentType);
conn.setRequestMethod(httpMethod);
conn.setConnectTimeout(30000);
// prepare request body (for XML only)
if( (jobPropsPath != null) && ("POST".equals(httpMethod)) ) {
File jobPropsXml = new File(jobPropsPath.getPath());
if(jobPropsXml.exists()) {
String jobPropsSerialized = this.serializeXml(jobPropsXml);
conn.setDoOutput(true);
// Add serialized String to a request body
try(OutputStream output = new BufferedOutputStream(conn.getOutputStream())) {
output.write(jobPropsSerialized.getBytes());
output.flush();
}
} else {
throw new IOException("Requested file does not exist in specified path.");
}
}
// Process response
int status = conn.getResponseCode();
StringBuilder sb = new StringBuilder();
switch (status) {
...
}
conn.disconnect();
return new JSONParser().parse(sb.toString());
}
这里是等效的 curl 调用（为了更清楚）
curl -i -k --negotiate -u : -X POST -H "Content-Type: application/xml" -d foo/bar/wf.xml "https://host:port/oozie/v1/jobs"
堆栈跟踪：
java.lang.RuntimeException: java.lang.NullPointerException
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1488)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)
at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(HttpURLConnection.java:3018)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:489)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:338)
at foo.bar.proj.OozieWorkflowTest.executeRequest(OozieWorkflowTest.java:193)
at foo.bar.proj.OozieWorkflowTest.testWorkflowOverRestApi(OozieWorkflowTest.java:120)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at junit.framework.TestCase.runTest(TestCase.java:176)
at junit.framework.TestCase.runBare(TestCase.java:141)
at junit.framework.TestResult.protect(TestResult.java:122)
at junit.framework.TestResult.runProtected(TestResult.java:142)
at junit.framework.TestResult.run(TestResult.java:125)
at junit.framework.TestCase.run(TestCase.java:129)
at junit.framework.TestSuite.runTest(TestSuite.java:252)
at junit.framework.TestSuite.run(TestSuite.java:247)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:86)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at org.junit.vintage.engine.execution.RunnerExecutor.execute(RunnerExecutor.java:42)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline.accept(ReferencePipeline.java:193)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.vintage.engine.VintageTestEngine.executeAllChildren(VintageTestEngine.java:83)
at org.junit.vintage.engine.VintageTestEngine.execute(VintageTestEngine.java:74)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:74)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.NullPointerException
at java.util.Base64$Encoder.encode(Base64.java:261)
at java.util.Base64$Encoder.encodeToString(Base64.java:315)
at sun.net.www.protocol.http.NegotiateAuthentication.setHeaders(NegotiateAuthentication.java:182)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1731)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
... 38 more
错误是由于随请求一起发送的XML文件中的一些语法错误，导致无法正确处理整个请求。但是，curl 请求至少返回了 400，而 Java 根本没有得到任何响应。我创建了一个错误报告，但机会不大，因为 API 是私有的，否则很难重现此行为。
我的 POST 请求在 getResponseCode() 处抛出一个 NullPointerException，但是，直到今天它都运行良好。等效的 curl 调用可以正常工作，因此问题应该在 Java 中。同样的实现（当然没有一些属性）适用于 GET 请求。这是：
private Object executeRequest(URL url, String httpMethod, String contentType, URL jobPropsPath)
throws NoSuchAlgorithmException, KeyManagementException,
MalformedURLException, IOException, ParseException {
if(contentType == null) {
contentType = "application/json";
}
// curl -k
TrustManager[] trustAllCerts = { new OozieWorkflowTest.CustomX509TrustManager() };
SSLContext sc = SSLContext.getInstance("SSL");
sc.init(null, trustAllCerts, new SecureRandom());
HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
HostnameVerifier allHostsValid = (hostname, session) -> true;
HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);
// execute a request
HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
conn.setRequestProperty("Content-Type", contentType);
conn.setRequestMethod(httpMethod);
conn.setConnectTimeout(30000);
// prepare request body (for XML only)
if( (jobPropsPath != null) && ("POST".equals(httpMethod)) ) {
File jobPropsXml = new File(jobPropsPath.getPath());
if(jobPropsXml.exists()) {
String jobPropsSerialized = this.serializeXml(jobPropsXml);
conn.setDoOutput(true);
// Add serialized String to a request body
try(OutputStream output = new BufferedOutputStream(conn.getOutputStream())) {
output.write(jobPropsSerialized.getBytes());
output.flush();
}
} else {
throw new IOException("Requested file does not exist in specified path.");
}
}
// Process response
int status = conn.getResponseCode();
StringBuilder sb = new StringBuilder();
switch (status) {
...
}
conn.disconnect();
return new JSONParser().parse(sb.toString());
}
这里是等效的 curl 调用（为了更清楚）
curl -i -k --negotiate -u : -X POST -H "Content-Type: application/xml" -d foo/bar/wf.xml "https://host:port/oozie/v1/jobs"
堆栈跟踪：
java.lang.RuntimeException: java.lang.NullPointerException
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1488)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)
at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(HttpURLConnection.java:3018)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:489)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:338)
at foo.bar.proj.OozieWorkflowTest.executeRequest(OozieWorkflowTest.java:193)
at foo.bar.proj.OozieWorkflowTest.testWorkflowOverRestApi(OozieWorkflowTest.java:120)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at junit.framework.TestCase.runTest(TestCase.java:176)
at junit.framework.TestCase.runBare(TestCase.java:141)
at junit.framework.TestResult.protect(TestResult.java:122)
at junit.framework.TestResult.runProtected(TestResult.java:142)
at junit.framework.TestResult.run(TestResult.java:125)
at junit.framework.TestCase.run(TestCase.java:129)
at junit.framework.TestSuite.runTest(TestSuite.java:252)
at junit.framework.TestSuite.run(TestSuite.java:247)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:86)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at org.junit.vintage.engine.execution.RunnerExecutor.execute(RunnerExecutor.java:42)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline.accept(ReferencePipeline.java:193)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.vintage.engine.VintageTestEngine.executeAllChildren(VintageTestEngine.java:83)
at org.junit.vintage.engine.VintageTestEngine.execute(VintageTestEngine.java:74)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:74)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.NullPointerException
at java.util.Base64$Encoder.encode(Base64.java:261)
at java.util.Base64$Encoder.encodeToString(Base64.java:315)
at sun.net.www.protocol.http.NegotiateAuthentication.setHeaders(NegotiateAuthentication.java:182)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1731)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
... 38 more
错误是由于随请求一起发送的XML文件中的一些语法错误，导致无法正确处理整个请求。但是，curl 请求至少返回了 400，而 Java 根本没有得到任何响应。我创建了一个错误报告，但机会不大，因为 API 是私有的，否则很难重现此行为。