com.redhat.developers.containers.MyController.java Source code

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Here is the source code for com.redhat.developers.containers.MyController.java

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/**
 * JBoss, Home of Professional Open Source
 * Copyright 2016, Red Hat, Inc. and/or its affiliates, and individual
 * contributors by the @authors tag. See the copyright.txt in the
 * distribution for a full listing of individual contributors.
 * <p/>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.redhat.developers.containers;

import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api")
public class MyController {

    @CrossOrigin
    @RequestMapping(method = RequestMethod.GET, value = "/hello", produces = "text/plain")
    public String hello() {
        String hostname = System.getenv().getOrDefault("HOSTNAME", "Unknown");
        return String.format("Hello world from %s", hostname);
    }

    @CrossOrigin
    @RequestMapping(method = RequestMethod.GET, value = "/memory", produces = "text/plain")
    public String memory() {
        System.out.println("Starting to allocate memory...");
        Runtime rt = Runtime.getRuntime();
        StringBuilder sb = new StringBuilder();
        long maxMemory = rt.maxMemory();
        long usedMemory = 0;
        while (((float) usedMemory / maxMemory) < 0.80) {
            sb.append(System.nanoTime() + sb.toString());
            usedMemory = rt.totalMemory();
        }
        String msg = "Allocated more than 80% (" + humanReadableByteCount(usedMemory, false)
                + ") of the max allowed JVM memory size (" + humanReadableByteCount(maxMemory, false) + ")";
        System.out.println(msg);
        return msg;
    }

    public static String humanReadableByteCount(long bytes, boolean si) {
        int unit = si ? 1000 : 1024;
        if (bytes < unit)
            return bytes + " B";
        int exp = (int) (Math.log(bytes) / Math.log(unit));
        String pre = (si ? "kMGTPE" : "KMGTPE").charAt(exp - 1) + (si ? "" : "i");
        return String.format("%.1f %sB", bytes / Math.pow(unit, exp), pre);
    }

    @RequestMapping(method = RequestMethod.GET, value = "/health")
    public String health() {
        return "I'm ok";
    }

}