[Stackdriver Error Reporting][error-reporting] Stackdriver Error Reporting counts, analyzes and aggregates the crashes in your running cloud services.

A [centralized error management interface](https://console.cloud.google.com/errors) displays the results with sorting and filtering capabilities.

This sample Java application demonstrates how errors are automatically sent to Error reporting in applications running in [App Engine Flex environment][ae-flex].

It also demonstrates how to send custom error events using the Error Reporting API.

[error-reporting]: https://cloud.google.com/error-reporting/

[ae-flex]: https://cloud.google.com/appengine/docs/flexible/java

[google-cloud-java]: https://github.com/GoogleCloudPlatform/google-cloud-java

1. Install [Maven](http://maven.apache.org/).

1. Install and initialize [GCloud SDK](https://cloud.google.com/sdk/downloads).

1. [Enable](https://console.cloud.google.com/apis/api/clouderrorreporting.googleapis.com/overview) Stack Driver Error Reporting API.

(Note : only required for logging custom events using the Error Reporting API)

Build your project with:

1. Authorize the local environment

For local testing, we will be using the [Jetty Maven plugin](http://www.eclipse.org/jetty/documentation/9.4.x/jetty-maven-plugin.html).

Run:

Access [http://localhost:8080/error](http://localhost:8080/error) endpoint.

After accessing the `/error` endpoint, check the [error reporting console](https://console.cloud.google.com/errors).

Confirm that you see the custom error reported using the error reporting API.

Run:

Access [https://YOUR_PROJECT_ID.appspot.com/error] endpoint.

After accessing the `/error` endpoint, check the [error reporting console](https://console.cloud.google.com/errors).

Confirm that you see:

1. IllegalArgumentException logged via the standard logging framework.

1. Custom error reported using the error reporting API.

1. Runtime exception.

<project>

<modelVersion>4.0.0</modelVersion>

<packaging>war</packaging>

<version>1.0-SNAPSHOT</version>

<groupId>com.example.flexible</groupId>

<artifactId>flexible-error-reporting</artifactId>

<parent>

<artifactId>doc-samples</artifactId>

<groupId>com.google.cloud</groupId>

<version>1.0.0</version>

<relativePath>../..</relativePath>

</parent>

<properties>

<appengine.maven.plugin>1.3.1</appengine.maven.plugin>

<maven.compiler.target>1.8</maven.compiler.target>

<maven.compiler.source>1.8</maven.compiler.source>

<failOnMissingWebXml>false</failOnMissingWebXml>

<jetty.maven.plugin>9.4.6.v20170531</jetty.maven.plugin>

</properties>

<!-- Temporary workaround for known issue : https://github.com/GoogleCloudPlatform/google-cloud-java/issues/2192 -->

<dependencyManagement>

<dependencies>

<dependency>

<groupId>com.google.auth</groupId>

<artifactId>google-auth-library-credentials</artifactId>

<version>0.6.1</version>

</dependency>

<dependency>

<groupId>com.google.auth</groupId>

<artifactId>google-auth-library-oauth2-http</artifactId>

<version>0.6.1</version>

</dependency>

</dependencies>

</dependencyManagement>

<dependencies>

<dependency>

<groupId>javax.servlet</groupId>

<artifactId>javax.servlet-api</artifactId>

<version>3.1.0</version>

<type>jar</type>

<scope>provided</scope>

</dependency>

<dependency>

<groupId>com.google.cloud</groupId>

<artifactId>google-cloud-errorreporting</artifactId>

<version>0.20.0-alpha</version>

</dependency>

</dependencies>

<build>

<!-- for hot reload of the web application -->

<outputDirectory>${project.build.directory}/${project.build.finalName}/WEB-INF/classes</outputDirectory>

<plugins>

<plugin>

<groupId>com.google.cloud.tools</groupId>

<artifactId>appengine-maven-plugin</artifactId>

<version>${appengine.maven.plugin}</version>

<configuration>

<!-- deploy configuration -->

</configuration>

</plugin>

<plugin>

<groupId>org.eclipse.jetty</groupId>

<artifactId>jetty-maven-plugin</artifactId>

<version>${jetty.maven.plugin}</version>

</plugin>

</plugins>

</build>

</project>

runtime: java

env: flex

handlers:

- url: /.*

script: this field is required, but ignored

package com.example.flexible.errorreporting;

import com.google.cloud.ServiceOptions;

import com.google.cloud.errorreporting.v1beta1.ReportErrorsServiceClient;

import com.google.devtools.clouderrorreporting.v1beta1.ProjectName;

import com.google.devtools.clouderrorreporting.v1beta1.ReportedErrorEvent;

import java.io.IOException;

import java.io.PrintWriter;

import java.io.StringWriter;

import java.util.logging.Level;

import java.util.logging.Logger;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

@WebServlet(name = "Error reporting", value = "/error")

public class ErrorReportingExample extends HttpServlet {

private Logger logger = Logger.getLogger(ErrorReportingExample.class.getName());

@Override

public void doGet(HttpServletRequest req, HttpServletResponse resp)

throws IOException, ServletException {

// errors logged to stderr / Cloud logging with exceptions are automatically reported.

logger.log(Level.SEVERE, "exception using log framework", new IllegalArgumentException());

// use the error-reporting client library to log custom error events

logCustomErrorEvent();

// runtime exceptions are also automatically picked up by error reporting.

throw new RuntimeException("this is a runtime exception");

}

private void logCustomErrorEvent() {

try (ReportErrorsServiceClient reportErrorsServiceClient = ReportErrorsServiceClient.create()) {

// custom exception logged using the API

Exception e = new Exception("custom event reported using the API");

// Events reported using the API must contain a stack trace message

StringWriter stackTrace = new StringWriter();

e.printStackTrace(new PrintWriter(stackTrace));

ReportedErrorEvent errorEvent =

ReportedErrorEvent.getDefaultInstance()

.toBuilder()

.setMessage(stackTrace.toString())

.build();

// default project id

ProjectName projectName = ProjectName.create(ServiceOptions.getDefaultProjectId());

reportErrorsServiceClient.reportErrorEvent(projectName, errorEvent);

} catch (Exception e) {

logger.log(Level.SEVERE, "Exception encountered logging custom event", e);

}

}

}

<module>flexible/errorreporting</module>