public class DemoServlet扩展HttpServlet { / * 用于从REST API获取数据并将其放入的代码 HashMap Collection然后从该集合创建管道并将管道写入bq表* /
String [] credentials = {“ - project =”+ projectId，“ - stagingLocation =”+ staggingLocation}; PipelineOptionsFactory.Builder builder = PipelineOptionsFactory.fromArgs（credentials）; PipelineOptions options = builder.create（）;
//Setting to run the pipeline in google cloud.By Changing this parameter we can run even in local mode
options.setRunner(DataflowPipelineRunner.class);
//Creating pipeline with above options
Pipeline youTubeChannelPipeline = Pipeline.create(options);
PCollection<String> lines = null;
lines = youTubeChannelPipeline.apply(Create.of(allValues)).setCoder(StringUtf8Coder.of());
//Transforming PCollection<String> to PCollection<TableRow> and then writing to bq
bqRows = lines.apply（ParDo.named（“将字符串转换为TableRow”）。（new DoFn（）{ @覆盖 public void processElement（ProcessContext pc）throws Exception { TableRow tmpRow = new TableRow（）; String [] columns = pc.element（）。split（YoutubeConstants.COMA_DELIMITER）; for（int i = 0; i＆lt; no_of_col; i ++）{ tmpRow.set（YoutubeConstants.CHANNEL_LEVEL_HEADERS [i]，columns [i]）; } pc.output（tmpRow）; } }））;
//Writing the rows in bq table
bqRows.apply(BigQueryIO.Write
.named("Write To BQ")
.to(destination_path)
.withSchema(schema)
.withWriteDisposition(BigQueryIO.Write.WriteDisposition.WRITE_APPEND)
.withCreateDisposition(BigQueryIO.Write.CreateDisposition.CREATE_IF_NEEDED));
youTubeChannelPipeline.run();
W 12:36:16.124 /demo
java.lang.RuntimeException: Failed to construct instance from factory method com.google.cloud.dataflow.sdk.runners.DataflowPipelineRunner#fromOptions
at com.google.cloud.dataflow.sdk.util.InstanceBuilder.buildFromMethod(InstanceBuilder.java:228)
at com.google.cloud.dataflow.sdk.util.InstanceBuilder.build(InstanceBuilder.java:161)
at com.google.cloud.dataflow.sdk.runners.PipelineRunner.fromOptions(PipelineRunner.java:52)
at com.google.cloud.dataflow.sdk.Pipeline.create(Pipeline.java:117)
at myapp.DemoServlet.doGet(DemoServlet.java:91)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.JdbcMySqlConnectionCleanupFilter.doFilter(JdbcMySqlConnectionCleanupFilter.java:60)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:257)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:146)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:482)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:437)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:444)
at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:230)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:308)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:300)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:441)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:234)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at com.google.appengine.runtime.Request.process-8f9b045d763b7321(Request.java)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:45)
at com.google.cloud.dataflow.sdk.util.InstanceBuilder.buildFromMethod(InstanceBuilder.java:221)
at com.google.cloud.dataflow.sdk.util.InstanceBuilder.build(InstanceBuilder.java:161)
at com.google.cloud.dataflow.sdk.runners.PipelineRunner.fromOptions(PipelineRunner.java:52)
at com.google.cloud.dataflow.sdk.Pipeline.create(Pipeline.java:117)
at myapp.DemoServlet.doGet(DemoServlet.java:91)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:437)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:444)
at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:230)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:308)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:300)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:441)
... 1 more
Caused by: java.lang.RuntimeException: Unable to get application default credentials. Please see https://developers.google.com/accounts/docs/application-default-credentials for details on how to specify credentials. This version of the SDK is dependent on the gcloud core component version 2015.02.05 or newer to be able to get credentials from the currently authorized user via gcloud auth.
at com.google.cloud.dataflow.sdk.util.Credentials.getCredential(Credentials.java:122)
at com.google.cloud.dataflow.sdk.util.GcpCredentialFactory.getCredential(GcpCredentialFactory.java:43)
at com.google.cloud.dataflow.sdk.options.GcpOptions$GcpUserCredentialsFactory.create(GcpOptions.java:185)
at com.google.cloud.dataflow.sdk.options.GcpOptions$GcpUserCredentialsFactory.create(GcpOptions.java:175)
at com.google.cloud.dataflow.sdk.options.ProxyInvocationHandler.getDefault(ProxyInvocationHandler.java:288)
at com.google.cloud.dataflow.sdk.options.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:127)
at com.sun.proxy.$Proxy20.getGcpCredential(Unknown Source)
at com.google.cloud.dataflow.sdk.util.Transport.newDataflowClient(Transport.java:120)
at com.google.cloud.dataflow.sdk.options.DataflowPipelineDebugOptions$DataflowClientFactory.create(DataflowPipelineDebugOptions.java:157)
at com.google.cloud.dataflow.sdk.options.DataflowPipelineDebugOptions$DataflowClientFactory.create(DataflowPipelineDebugOptions.java:154)
at com.google.cloud.dataflow.sdk.options.ProxyInvocationHandler.getDefault(ProxyInvocationHandler.java:288)
at com.google.cloud.dataflow.sdk.options.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:127)
at com.sun.proxy.$Proxy20.getDataflowClient(Unknown Source)
at com.google.cloud.dataflow.sdk.runners.DataflowPipelineRunner.<init>(DataflowPipelineRunner.java:160)
<continued in next message>
W 12:36:16.124 <continued from previous message>
at com.google.cloud.dataflow.sdk.runners.DataflowPipelineRunner.fromOptions(DataflowPipelineRunner.java:155)
... 34 more
Caused by: java.io.IOException: Application Default Credentials failed to create the Google App Engine service account credentials class com.google.api.client.googleapis.extensions.appengine.auth.oauth2.AppIdentityCredential$AppEngineCredentialWrapper. Check that the component 'google-api-client-appengine' is deployed.
at com.google.api.client.googleapis.auth.oauth2.DefaultCredentialProvider.tryGetAppEngineCredential(DefaultCredentialProvider.java:274)
at com.google.api.client.googleapis.auth.oauth2.DefaultCredentialProvider.getDefaultCredentialUnsynchronized(DefaultCredentialProvider.java:159)
at com.google.api.client.googleapis.auth.oauth2.DefaultCredentialProvider.getDefaultCredential(DefaultCredentialProvider.java:86)
at com.google.api.client.googleapis.auth.oauth2.GoogleCredential.getApplicationDefault(GoogleCredential.java:213)
at com.google.api.client.googleapis.auth.oauth2.GoogleCredential.getApplicationDefault(GoogleCredential.java:191)
at com.google.cloud.dataflow.sdk.util.Credentials.getCredential(Credentials.java:120)
... 48 more
Caused by: java.lang.ClassNotFoundException: com.google.api.client.googleapis.extensions.appengine.auth.oauth2.AppIdentityCredential$AppEngineCredentialWrapper
at com.google.appengine.runtime.Request.process-8f9b045d763b7321(Request.java)
at java.lang.Class.forName(Class.java:136)
at com.google.api.client.googleapis.auth.oauth2.DefaultCredentialProvider.forName(DefaultCredentialProvider.java:208)
at com.google.api.client.googleapis.auth.oauth2.DefaultCredentialProvider.tryGetAppEngineCredential(DefaultCredentialProvider.java:259)
... 53 more
答案 0 :(得分：3)
支持在AppEngine中通过Application Default Credentials获取与数据流兼容的凭据，存在于1.9.20+版本的Google API库中。请确保您部署到AppEngine的WAR包含google-api-client版本1.9.20+和google-api-client-appengine版本1.9.20+。请注意，由于此更改，您可能需要升级其他依赖项。