SimpleJMXWriter.java

import io.vertx.core.Handler;
import io.vertx.core.json.JsonArray;
import io.vertx.core.json.JsonObject;
import io.vertx.ext.web.RoutingContext;

import java.lang.management.ManagementFactory;
import com.sun.management.OperatingSystemMXBean;
import java.lang.management.RuntimeMXBean;

public class SimpleJMXWriter implements Handler<RoutingContext> {
    private static final OperatingSystemMXBean osBean = (OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();
    private static final RuntimeMXBean runtimeBean = ManagementFactory.getRuntimeMXBean();

    @Override
    public void handle(RoutingContext ctx) {
        JsonArray statisticsRequested = ctx.getBodyAsJson().getJsonArray("statistics");
        JsonObject response = new JsonObject();
        for (Object obj : statisticsRequested.getList()) {
            if (obj instanceof String) {
                writeStatistic((String) obj, response);
            }
        }
        ctx.response().putHeader("Content-Type", "application/json").end(response.toString());
    }

    private void writeStatistic(String statistic, JsonObject jsonObject) {
        // Autogenerated
        // Could use cached reflection but slower
        switch (statistic) {
            case "availableProcessors":
                jsonObject.put(statistic, osBean.getAvailableProcessors());
                break;
            case "arch":
                jsonObject.put(statistic, osBean.getArch());
                break;
            case "name":
                jsonObject.put(statistic, osBean.getName());
                break;
            case "systemLoadAverage":
                jsonObject.put(statistic, osBean.getSystemLoadAverage());
                break;
            case "version":
                jsonObject.put(statistic, osBean.getVersion());
                break;
            case "committedVirtualMemorySize":
                jsonObject.put(statistic, osBean.getCommittedVirtualMemorySize());
                break;
            case "freePhysicalMemorySize":
                jsonObject.put(statistic, osBean.getFreePhysicalMemorySize());
                break;
            case "freeSwapSpaceSize":
                jsonObject.put(statistic, osBean.getFreeSwapSpaceSize());
                break;
            case "processCpuLoad":
                jsonObject.put(statistic, osBean.getProcessCpuLoad());
                break;
            case "processCpuTime":
                jsonObject.put(statistic, osBean.getProcessCpuTime());
                break;
            case "systemCpuLoad":
                jsonObject.put(statistic, osBean.getSystemCpuLoad());
                break;
            case "totalPhysicalMemorySize":
                jsonObject.put(statistic, osBean.getTotalPhysicalMemorySize());
                break;
            case "totalSwapSpaceSize":
                jsonObject.put(statistic, osBean.getTotalSwapSpaceSize());
                break;
            case "startTime":
                jsonObject.put(statistic, runtimeBean.getStartTime());
                break;
            case "uptime":
                jsonObject.put(statistic, runtimeBean.getUptime());
                break;
            case "vmVersion":
                jsonObject.put(statistic, runtimeBean.getVmVersion());
                break;
            default:
        }
    }
}