groovy.md

description
Enhance the developer experience by scripting the Live API and make proof of concepts even faster

Groovy support

The groovy plugin is available for download on INTELIE Live Marketplace.

It provides the capability to register and run Groovy snippets, using the same API that is available to Java.

A Groovy snippet is limited to be a standalone piece of code, which means it is unable to declare and use other plugin dependencies. If you need to write a more advanced Groovy code, you must upload that code as a Groovy script in Plugins administration page.

For example, the snippet below adds a resource to get a thread dump.

import java.lang.management.LockInfo;
import java.lang.management.ManagementFactory;
import java.lang.management.MonitorInfo;
import java.lang.management.ThreadInfo;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;

live.web().addService("threaddump", new ThreadDumpService());

@Path("/")
@Produces("text/plain")
public class ThreadDumpService {

    @GET
    public String threadDump() {
        return formatStackTraces() + 
          "\n---------------------------------------------------\n" +
          memoryInformation() +
           "\n---------------------------------------------------\n" +
          garbageCollectorInformation()
    }
  
    String formatStackTraces() {
        ThreadInfo[] allThreads = ManagementFactory.getThreadMXBean().dumpAllThreads(true, true);

        StringBuilder dump = new StringBuilder();

        for (ThreadInfo threadInfo : allThreads) {
            dump.append("Thread: [").append(threadInfo.getThreadName())
                    .append("] state=").append(threadInfo.getThreadState()).append("\n");

            if (threadInfo.getLockInfo() != null) {
                dump.append("Waiting ").append(threadInfo.getLockInfo()).append("\n");
            }

            if (threadInfo.getLockedMonitors() != null && threadInfo.getLockedMonitors().length > 0) {
                dump.append("Currently locking monitors:\n");
                for(MonitorInfo monitor : threadInfo.getLockedMonitors()) {
                    dump.append(" - ").append(monitor).append("\n");
                }
            }

            if (threadInfo.getLockedSynchronizers() != null && threadInfo.getLockedSynchronizers().length > 0) {
                dump.append("Currently locking Synchronizers:\n");
                for(LockInfo synchronizer : threadInfo.getLockedSynchronizers()) {
                    dump.append(" - ").append(synchronizer).append("\n");
                }
            }

            for (StackTraceElement traceElement : threadInfo.getStackTrace()) {
                dump.append("    at ").append(traceElement).append("\n");
            }

            dump.append("\n");
        }

        return dump.toString();
    }
 
  String memoryInformation() {
    StringBuilder memInfo = new StringBuilder();
    
    def memMxBean = ManagementFactory.memoryMXBean
    
    memInfo.append("Head Memory Usage: ").append(memMxBean.heapMemoryUsage)
    	.append("\nNonHead Memory Usage: ").append(memMxBean.nonHeapMemoryUsage)
    
    return memInfo.toString();
  }
  
  String garbageCollectorInformation() {
    
    StringBuilder gcInfo = new StringBuilder();
    
    ManagementFactory.garbageCollectorMXBeans.each {gc ->
      gcInfo.append("MemoryManager: ").append(gc.name).append(" valid: ").append(gc.valid)
      	.append(" collectionCount: ").append(gc.collectionCount).append(" collectionTime: ").append(gc.collectionTime).append("\n")
    }
    
    return gcInfo.toString()
  }
}