MiniProfiler-JVM

This library provides (some of) the functionality of the StackExchange MiniProfiler for JVM-based applications.

(Screenshot)

Installation

The JVM MiniProfiler is deployed to Maven Central and can be added to your project as a dependency using the following coordinates:

groupId: io.jdev.miniprofiler
artifactId: miniprofiler-core
version: 0.8.2

Or just download the jar from http://search.maven.org/ if your build system is a bit less connected.

Basic Usage

Once installed, start using the profiler thusly:

Profiler profiler = MiniProfiler.start("/url/my web request");
try {
    // do some stuff
} finally {
    profiler.stop();
}

To profile individual parts of your program, create and stop individual timings:

Timing t = MiniProfiler.current().step("My complicated step");
try {
    // stuff
} finally {
    timing.stop();
}

If you are using Java 7, you can use Java 7 auto-closable resource blocks for even cleaner code:

try (Timing t = MiniProfiler.current().step("My complicated step")) {
    // stuff
}

Steps are nestable, and will appear nested in profiler output:

try (Timing t = MiniProfiler.current().step("My complicated step")) {
    // stuff
    try (Timing t1 = MiniProfiler.current().step("A sub-part of the complicated step")) {
        // sub-stuff 1
    }
    try (Timing t2 = MiniProfiler.current().step("A second, sibling sub-part of the complicated step")) {
        // sub-stuff 2
    }
}

Usage with Dependency Injection

The default code above uses a static reference to a global ProfilerProvider object. If you are using a dependency injection framework such as Spring or Guice, or if you just like more testable code, then create a ProfilerProvider and inject it into your code. The included DefaultProfilerProvider should be enough for most purposes. Then use it in your code like this:

// at start of request
Profiler profiler = profilerProvider.start("/url/my web request");
try {
    // do some stuff
} finally {
    profiler.stop();
}


// further in where stuff is happening
Timing t = profilerProvider.current().step("My complicated step");
try {
    // stuff
} finally {
    timing.stop();
}

Profiling JDBC Queries

To see your SQL queries in your profiling output, just wrap your JDBC DataSource in the ProfilingDataSource, and call getConnection() on that data source as normal.

Seeing the output

To see the output of the profiled request on your web page, add a script tag to the bottom of your HTML page, just inside the body tag. The library comes with a ScriptTagWriter class to help with this:

<%= new ScriptTagWriter().printScriptTag(MiniProfiler.current(), request.getContextPath() + "/miniprofiler")%>

This will output a javascript script tag which will load the necessary javascript, css and data from under /miniprofiler in your web app.

Inclusion in Servlet Web App

The core library includes a ProfilingFilter which does several jobs:

• Start and stop profiling for all web requests, excluding anything that looks like a file to be served up directly
• Serve up front-end javascript, CSS and templates used for displaying the profiling info in a web page
• Serve up profiling data as JSON

The filter can be included in your web.xml like this:

<filter>
	<filter-name>miniprofiler</filter-name>
	<filter-class>io.jdev.miniprofiler.servlet.ProfilingFilter</filter-class>
</filter>

<filter-mapping>
	<filter-name>miniprofiler</filter-name>
	<url-pattern>/*</url-pattern>
</filter-mapping>

By default, the filter will expect requests for the static resources and data under /miniprofiler in your web app. You can change this by passing it an init-param of path. Be sure to pass the same value to the ScriptTagWriter if you are using that.

The filter can also be configured to accept cross-origin requests by passing an allowed-origin init-param with the value that you would like the Access-Control-Allow-Origin header to be.

Inclusion in Java EE applications with CDI

There are a couple of extra pieces of support for modern Java EE applications. Simply include the miniprofiler-javaee module:

groupId: io.jdev.miniprofiler
artifactId: miniprofiler-javaee
version: 0.8.2

That module contains a DefaultCDIProfilerProvider which is a ProfilerProvider instance ready to be injected into your CDI-managed beans.

It also contains an interceptor for profiling EJB calls. Add the following to your beans.xml:

<interceptors>
    <class>io.jdev.miniprofiler.javaee.ProfilingEJBInterceptor</class>
</interceptors>

Then add the @Profiled annotation to any EJB that you want profiled, and EJB method calls will appear in your profiler output.

Feedback / Contributions

Please raise issues in the GitHub issue tracker