Export Java Telemetry to Azure Monitor

This skill covers com.azure:azure-monitor-opentelemetry-exporter for Java, which exports OpenTelemetry telemetry (spans and metrics) to Azure Monitor / Application Insights. The package is deprecated in favor of azure-monitor-opentelemetry-autoconfigure, and the recommended setup wires the autoconfigure package into an AutoConfiguredOpenTelemetrySdkBuilder via AzureMonitorExporter.customize(sdkBuilder), reading the connection string from APPLICATIONINSIGHTS_CONNECTION_STRING or passing it explicitly. From there the skill covers standard OpenTelemetry usage: creating spans with a Tracer, setting attributes during a span's lifetime, nesting child spans that link to a parent via Context, recording exceptions with span.recordException() and setStatus(StatusCode.ERROR, ...), writing a custom SpanProcessor (implementing onStart/onEnd and isStartRequired/isEndRequired) to add attributes to every span and registering it via addTracerProviderCustomizer, and creating counter and histogram metrics with a Meter. Nested spans link automatically to their parent through the ambient Context when a child span is started while the parent's Scope is current, which is how a parentOperation/childOperation call chain produces a connected trace rather than two unrelated spans.

Do not start new work on azure-monitor-opentelemetry-exporter - it is explicitly deprecated. Use this skill only to understand or migrate an existing integration; new Application Insights instrumentation in Java should go directly through azure-monitor-opentelemetry-autoconfigure, which adds automatic instrumentation of common libraries and simplified configuration on top of the same OpenTelemetry SDK concepts documented here.

Configuration is the APPLICATIONINSIGHTS_CONNECTION_STRING environment variable (an InstrumentationKey plus IngestionEndpoint). A span with attributes and exception handling looks like this:

Span span = tracer.spanBuilder("processOrder")
    .setAttribute("order.id", "12345")
    .setAttribute("customer.tier", "premium")
    .startSpan();

try (Scope scope = span.makeCurrent()) {
    span.setAttribute("items.count", 3);
    span.setAttribute("total.amount", 99.99);
    processOrder();
} finally {
    span.end();
}

A LongCounter (built via meter.counterBuilder(...)) records event counts with attributes like http.method and http.status_code, and a LongHistogram (via meter.histogramBuilder(...).ofLongs()) records distributions like request latency in milliseconds - both flow through the same exporter to Azure Monitor once telemetry is generated.

Builds on the OpenTelemetry Java SDK (Tracer, Span, SpanProcessor, Meter) and exports to Azure Monitor / Application Insights; distributed via Maven Central as com.azure:azure-monitor-opentelemetry-exporter, with migration guidance pointing to the azure-monitor-opentelemetry-autoconfigure replacement package and its own Maven Central artifact.

Java developers maintaining or migrating an existing Application Insights integration built on this exporter - not a starting point for new instrumentation, which should target azure-monitor-opentelemetry-autoconfigure instead - and who follow OpenTelemetry conventions: meaningful span names, contextual attributes, exceptions always recorded, spans always ended in a finally block, and Scope managed via try-with-resources.