Fix latestDepTests and add readme.

Author: tylerbenson

instrumentation/servlet/servlet-3.0/library/README.md

@@ -0,0 +1,52 @@
+# Library Instrumentation for Java Servlet version 3.0 and higher
+
+Provides OpenTelemetry instrumentation for Java Servlets through a servlet filter.
+
+## Quickstart
+
+### Add these dependencies to your project
+
+Replace `OPENTELEMETRY_VERSION` with
+the [latest release](https://central.sonatype.com/artifact/io.opentelemetry.instrumentation/opentelemetry-lettuce-5.1).
+
+For Maven, add to your `pom.xml` dependencies:
+
+```xml
+
+<dependencies>
+  <dependency>
+    <groupId>io.opentelemetry.instrumentation</groupId>
+    <artifactId>opentelemetry-servlet-3.0</artifactId>
+    <version>OPENTELEMETRY_VERSION</version>
+  </dependency>
+</dependencies>
+```
+
+For Gradle, add to your dependencies:
+
+```kotlin
+implementation("io.opentelemetry.instrumentation:opentelemetry-servlet-3.0:OPENTELEMETRY_VERSION")
+```
+
+### Usage
+
+Add the filter to your `web.xml`
+
+```xml
+<web-app>
+  <filter>
+    <filter-name>OpenTelemetryServletFilter</filter-name>
+    <filter-class>io.opentelemetry.instrumentation.servlet.v3_0.OpenTelemetryServletFilter
+    </filter-class>
+    <async-supported>true</async-supported>
+  </filter>
+  <filter-mapping>
+    <filter-name>OpenTelemetryServletFilter</filter-name>
+    <url-pattern>/*</url-pattern>
+  </filter-mapping>
+</web-app>
+```
+
+Note: GlobalOpenTelemetry must be set before filter initialization. If you are unable to ensure it
+is set first, consider creating a subclass of `OpenTelemetryServletFilter` that handles
+initialization of GlobalOpenTelemetry in a static initializer or constructor.

instrumentation/servlet/servlet-3.0/library/build.gradle.kts

@@ -9,6 +9,12 @@ dependencies {
   testLibrary("org.eclipse.jetty:jetty-servlet:8.0.0.v20110901")
   testLibrary("org.apache.tomcat.embed:tomcat-embed-core:8.0.41")
   testLibrary("org.apache.tomcat.embed:tomcat-embed-jasper:8.0.41")
+
+  latestDepTestLibrary("org.eclipse.jetty:jetty-server:10.+")
+  latestDepTestLibrary("org.eclipse.jetty:jetty-servlet:10.+")
+
+  latestDepTestLibrary("org.apache.tomcat.embed:tomcat-embed-core:9.+")
+  latestDepTestLibrary("org.apache.tomcat.embed:tomcat-embed-jasper:9.+")
 }
 
 tasks {
@@ -18,3 +24,14 @@ tasks {
     jvmArgs("-XX:+IgnoreUnrecognizedVMOptions")
   }
 }
+
+// Servlet 3.0 in latest Jetty versions requires Java 11
+// However, projects that depend on this module are still be using Java 8 in testLatestDeps mode
+// Therefore, we need a separate project for servlet 3.0 tests
+val latestDepTest = findProperty("testLatestDeps") as Boolean
+
+if (latestDepTest) {
+  otelJava {
+    minJavaVersionSupported.set(JavaVersion.VERSION_11)
+  }
+}