ClassLoader Leak Example

ClassLoaderLeakExample.java

// modify from https://gist.github.com/dpryden/b2bb29ee2d146901b4ae

import java.io.IOException;
import java.lang.management.ManagementFactory;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;

/**
 * @author caorong
 */
public final class ClassLoaderLeakExample {


  public static final String PID = ManagementFactory.getRuntimeMXBean().getName().split("@")[0];

  static volatile boolean running = true;

  public static void main(String[] args) throws Exception {
    for (int i = 0; i < 10; i++) {
      System.out.println("=========================" + PID);
    }
    Thread.sleep(1000 * 8);
    Thread thread = new LongRunningThread();
    try {
      thread.start();
      System.out.println("Running, press any key to stop.");
      System.in.read();
    } finally {
      running = false;
      thread.join();
    }
  }

  /**
   * Implementation of the thread. It just calls {@link #loadAndDiscard()}
   * in a loop.
   */
  static final class LongRunningThread extends Thread {
    @Override public void run() {
      while(running) {
        try {
          loadAndDiscard();
        } catch (Throwable ex) {
          ex.printStackTrace();
        }
        try {
          Thread.sleep(60);
        } catch (InterruptedException ex) {
          System.out.println("Caught InterruptedException, shutting down.");
          running = false;
        }
      }
    }
  }

  /**
   * A simple ClassLoader implementation that is only able to load one
   * class, the LoadedInChildClassLoader class. We have to jump through
   * some hoops here because we explicitly want to ensure we get a new
   * class each time (instead of reusing the class loaded by the system
   * class loader). If this child class were in a JAR file that wasn't
   * part of the system classpath, we wouldn't need this mechanism.
   */
  static final class ChildOnlyClassLoader extends ClassLoader {
    ChildOnlyClassLoader() {
      super(ClassLoaderLeakExample.class.getClassLoader());
    }

    @Override protected Class<?> loadClass(String name, boolean resolve)
        throws ClassNotFoundException {
      if (!ExampleClz.class.getName().equals(name)) {
        return super.loadClass(name, resolve);
      }
      try {
        Path path = Paths.get("/Users/caorong/Documents/workspace_java/tester/target/classes",ExampleClz.class.getName()
            + ".class");
        byte[] classBytes = Files.readAllBytes(path);
        Class<?> c = defineClass(name, classBytes, 0, classBytes.length);
        if (resolve) {
          resolveClass(c);
        }
        return c;
      } catch (IOException ex) {
        throw new ClassNotFoundException("Could not load " + name, ex);
      }
    }
  }

  /**
   * Helper method that constructs a new ClassLoader, loads a single class,
   * and then discards any reference to them. Theoretically, there should
   * be no GC impact, since no references can escape this method! But in
   * practice this will leak memory like a sieve.
   */

  static ArrayList<ClassLoader> childClassLoaders = new ArrayList<ClassLoader>(33333);
  static void loadAndDiscard() throws Exception {
    ClassLoader childClassLoader = new ChildOnlyClassLoader();

    childClassLoaders.add(childClassLoader);
    Class<?> childClass = Class.forName(
        ExampleClz.class.getName(), true, childClassLoader);
    childClass.newInstance();

    // When this method returns, there will be no way to reference
    // childClassLoader or childClass at all, but they will still be
    // rooted for GC purposes!
  }
}

ExampleClz.java

/**
 * @author caorong
 */
public class ExampleClz {

  private static final int x0=0;
  private static final int x1=100;
  private static final int x2=200;
  private static final int x3=300;
  private static final int x4=400;
  private static final int x5=500;
  private static final int x6=600;
  private static final int x7=700;
  private static final int x8=800;
  private static final int x9=900;
  private static final int x10=1000;
  private static final int x11=1100;
  private static final int x12=1200;
  private static final int x13=1300;
  private static final int x14=1400;
  private static final int x15=1500;
  private static final int x16=1600;
  private static final int x17=1700;
  private static final int x18=1800;
  private static final int x19=1900;
  private static final int x20=2000;
  private static final int x21=2100;
  private static final int x22=2200;
  private static final int x23=2300;
  private static final int x24=2400;
  private static final int x25=2500;
  private static final int x26=2600;
  private static final int x27=2700;
  private static final int x28=2800;
  private static final int x29=2900;
  private static final int x30=3000;
  private static final int x31=3100;
  private static final int x32=3200;
  private static final int x33=3300;
  private static final int x34=3400;
  private static final int x35=3500;
  private static final int x36=3600;
  private static final int x37=3700;
  private static final int x38=3800;
  private static final int x39=3900;
  private static final int x40=4000;
  private static final int x41=4100;
  private static final int x42=4200;
  private static final int x43=4300;
  private static final int x44=4400;
  private static final int x45=4500;
  private static final int x46=4600;
  private static final int x47=4700;
  private static final int x48=4800;
  private static final int x49=4900;
  private static final int x50=5000;
  private static final int x51=5100;
  private static final int x52=5200;
  private static final int x53=5300;
  private static final int x54=5400;
  private static final int x55=5500;
  private static final int x56=5600;
  private static final int x57=5700;
  private static final int x58=5800;
  private static final int x59=5900;
  private static final int x60=6000;
  private static final int x61=6100;
  private static final int x62=6200;
  private static final int x63=6300;
  private static final int x64=6400;
  private static final int x65=6500;
  private static final int x66=6600;
  private static final int x67=6700;
  private static final int x68=6800;
  private static final int x69=6900;
  private static final int x70=7000;
  private static final int x71=7100;
  private static final int x72=7200;
  private static final int x73=7300;
  private static final int x74=7400;
  private static final int x75=7500;
  private static final int x76=7600;
  private static final int x77=7700;
  private static final int x78=7800;
  private static final int x79=7900;
  private static final int x80=8000;
  private static final int x81=8100;
  private static final int x82=8200;
  private static final int x83=8300;
  private static final int x84=8400;
  private static final int x85=8500;
  private static final int x86=8600;
  private static final int x87=8700;
  private static final int x88=8800;
  private static final int x89=8900;
  private static final int x90=9000;
  private static final int x91=9100;
  private static final int x92=9200;
  private static final int x93=9300;
  private static final int x94=9400;
  private static final int x95=9500;
  private static final int x96=9600;
  private static final int x97=9700;
  private static final int x98=9800;
  private static final int x99=9900;
  private static final int x100=10000;
  private static final int x101=10100;
  private static final int x102=10200;
  private static final int x103=10300;
  private static final int x104=10400;
  private static final int x105=10500;
  private static final int x106=10600;
  private static final int x107=10700;
  private static final int x108=10800;
  private static final int x109=10900;
  private static final int x110=11000;
  private static final int x111=11100;
  private static final int x112=11200;
  private static final int x113=11300;
  private static final int x114=11400;
  private static final int x115=11500;
  private static final int x116=11600;
  private static final int x117=11700;
  private static final int x118=11800;
  private static final int x119=11900;
  private static final int x120=12000;
  private static final int x121=12100;
  private static final int x122=12200;
  private static final int x123=12300;
  private static final int x124=12400;
  private static final int x125=12500;
  private static final int x126=12600;
  private static final int x127=12700;
  private static final int x128=12800;
  private static final int x129=12900;
  private static final int x130=13000;
  private static final int x131=13100;
  private static final int x132=13200;
  private static final int x133=13300;
  private static final int x134=13400;
  private static final int x135=13500;
  private static final int x136=13600;
  private static final int x137=13700;
  private static final int x138=13800;
  private static final int x139=13900;
  private static final int x140=14000;
  private static final int x141=14100;
  private static final int x142=14200;
  private static final int x143=14300;
  private static final int x144=14400;
  private static final int x145=14500;
  private static final int x146=14600;
  private static final int x147=14700;
  private static final int x148=14800;
  private static final int x149=14900;
  private static final int x150=15000;
  private static final int x151=15100;
  private static final int x152=15200;
  private static final int x153=15300;
  private static final int x154=15400;
  private static final int x155=15500;
  private static final int x156=15600;
  private static final int x157=15700;
  private static final int x158=15800;
  private static final int x159=15900;
  private static final int x160=16000;
  private static final int x161=16100;
  private static final int x162=16200;
  private static final int x163=16300;
  private static final int x164=16400;
  private static final int x165=16500;
  private static final int x166=16600;
  private static final int x167=16700;
  private static final int x168=16800;
  private static final int x169=16900;
  private static final int x170=17000;
  private static final int x171=17100;
  private static final int x172=17200;
  private static final int x173=17300;
  private static final int x174=17400;
  private static final int x175=17500;
  private static final int x176=17600;
  private static final int x177=17700;
  private static final int x178=17800;
  private static final int x179=17900;
  private static final int x180=18000;
  private static final int x181=18100;
  private static final int x182=18200;
  private static final int x183=18300;
  private static final int x184=18400;
  private static final int x185=18500;
  private static final int x186=18600;
  private static final int x187=18700;
  private static final int x188=18800;
  private static final int x189=18900;
  private static final int x190=19000;
  private static final int x191=19100;
  private static final int x192=19200;
  private static final int x193=19300;
  private static final int x194=19400;
  private static final int x195=19500;
  private static final int x196=19600;
  private static final int x197=19700;
  private static final int x198=19800;
  private static final int x199=19900;
  private static final int x200=20000;
  private static final int x201=20100;
  private static final int x202=20200;
  private static final int x203=20300;
  private static final int x204=20400;
  private static final int x205=20500;
  private static final int x206=20600;
  private static final int x207=20700;
  private static final int x208=20800;
  private static final int x209=20900;
  private static final int x210=21000;
  private static final int x211=21100;
  private static final int x212=21200;
  private static final int x213=21300;
  private static final int x214=21400;
  private static final int x215=21500;
  private static final int x216=21600;
  private static final int x217=21700;
  private static final int x218=21800;
  private static final int x219=21900;
  private static final int x220=22000;
  private static final int x221=22100;
  private static final int x222=22200;
  private static final int x223=22300;
  private static final int x224=22400;
  private static final int x225=22500;
  private static final int x226=22600;
  private static final int x227=22700;
  private static final int x228=22800;
  private static final int x229=22900;
  private static final int x230=23000;
  private static final int x231=23100;
  private static final int x232=23200;
  private static final int x233=23300;
  private static final int x234=23400;
  private static final int x235=23500;
  private static final int x236=23600;
  private static final int x237=23700;
  private static final int x238=23800;
  private static final int x239=23900;
  private static final int x240=24000;
  private static final int x241=24100;
  private static final int x242=24200;
  private static final int x243=24300;
  private static final int x244=24400;
  private static final int x245=24500;
  private static final int x246=24600;
  private static final int x247=24700;
  private static final int x248=24800;
  private static final int x249=24900;
  private static final int x250=25000;
  private static final int x251=25100;
  private static final int x252=25200;
  private static final int x253=25300;
  private static final int x254=25400;
  private static final int x255=25500;
  private static final int x256=25600;
  private static final int x257=25700;
  private static final int x258=25800;
  private static final int x259=25900;
  private static final int x260=26000;
  private static final int x261=26100;
  private static final int x262=26200;
  private static final int x263=26300;
  private static final int x264=26400;
  private static final int x265=26500;
  private static final int x266=26600;
  private static final int x267=26700;
  private static final int x268=26800;
  private static final int x269=26900;
  private static final int x270=27000;
  private static final int x271=27100;
  private static final int x272=27200;
  private static final int x273=27300;
  private static final int x274=27400;
  private static final int x275=27500;
  private static final int x276=27600;
  private static final int x277=27700;
  private static final int x278=27800;
  private static final int x279=27900;
  private static final int x280=28000;
  private static final int x281=28100;
  private static final int x282=28200;
  private static final int x283=28300;
  private static final int x284=28400;
  private static final int x285=28500;
  private static final int x286=28600;
  private static final int x287=28700;
  private static final int x288=28800;
  private static final int x289=28900;
  private static final int x290=29000;
  private static final int x291=29100;
  private static final int x292=29200;
  private static final int x293=29300;
  private static final int x294=29400;
  private static final int x295=29500;
  private static final int x296=29600;
  private static final int x297=29700;
  private static final int x298=29800;
  private static final int x299=29900;

  public String echo0(String echo) {
    return echo;
  }

  public String echo1(String echo) {
    return echo;
  }

  public String echo2(String echo) {
    return echo;
  }

  public String echo3(String echo) {
    return echo;
  }

  public String echo4(String echo) {
    return echo;
  }

  public String echo5(String echo) {
    return echo;
  }

  public String echo6(String echo) {
    return echo;
  }

  public String echo7(String echo) {
    return echo;
  }

  public String echo8(String echo) {
    return echo;
  }

  public String echo9(String echo) {
    return echo;
  }

  public String echo10(String echo) {
    return echo;
  }

  public String echo11(String echo) {
    return echo;
  }

  public String echo12(String echo) {
    return echo;
  }

  public String echo13(String echo) {
    return echo;
  }

  public String echo14(String echo) {
    return echo;
  }

  public String echo15(String echo) {
    return echo;
  }

  public String echo16(String echo) {
    return echo;
  }

  public String echo17(String echo) {
    return echo;
  }

  public String echo18(String echo) {
    return echo;
  }

  public String echo19(String echo) {
    return echo;
  }

  public String echo20(String echo) {
    return echo;
  }

  public String echo21(String echo) {
    return echo;
  }

  public String echo22(String echo) {
    return echo;
  }

  public String echo23(String echo) {
    return echo;
  }

  public String echo24(String echo) {
    return echo;
  }

  public String echo25(String echo) {
    return echo;
  }

  public String echo26(String echo) {
    return echo;
  }

  public String echo27(String echo) {
    return echo;
  }

  public String echo28(String echo) {
    return echo;
  }

  public String echo29(String echo) {
    return echo;
  }

  public String echo30(String echo) {
    return echo;
  }

  public String echo31(String echo) {
    return echo;
  }

  public String echo32(String echo) {
    return echo;
  }

  public String echo33(String echo) {
    return echo;
  }

  public String echo34(String echo) {
    return echo;
  }

  public String echo35(String echo) {
    return echo;
  }

  public String echo36(String echo) {
    return echo;
  }

  public String echo37(String echo) {
    return echo;
  }

  public String echo38(String echo) {
    return echo;
  }

  public String echo39(String echo) {
    return echo;
  }

  public String echo40(String echo) {
    return echo;
  }

  public String echo41(String echo) {
    return echo;
  }

  public String echo42(String echo) {
    return echo;
  }

  public String echo43(String echo) {
    return echo;
  }

  public String echo44(String echo) {
    return echo;
  }

  public String echo45(String echo) {
    return echo;
  }

  public String echo46(String echo) {
    return echo;
  }

  public String echo47(String echo) {
    return echo;
  }

  public String echo48(String echo) {
    return echo;
  }

  public String echo49(String echo) {
    return echo;
  }

  public String echo50(String echo) {
    return echo;
  }

  public String echo51(String echo) {
    return echo;
  }

  public String echo52(String echo) {
    return echo;
  }

  public String echo53(String echo) {
    return echo;
  }

  public String echo54(String echo) {
    return echo;
  }

  public String echo55(String echo) {
    return echo;
  }

  public String echo56(String echo) {
    return echo;
  }

  public String echo57(String echo) {
    return echo;
  }

  public String echo58(String echo) {
    return echo;
  }

  public String echo59(String echo) {
    return echo;
  }

  public String echo60(String echo) {
    return echo;
  }

  public String echo61(String echo) {
    return echo;
  }

  public String echo62(String echo) {
    return echo;
  }

  public String echo63(String echo) {
    return echo;
  }

  public String echo64(String echo) {
    return echo;
  }

  public String echo65(String echo) {
    return echo;
  }

  public String echo66(String echo) {
    return echo;
  }

  public String echo67(String echo) {
    return echo;
  }

  public String echo68(String echo) {
    return echo;
  }

  public String echo69(String echo) {
    return echo;
  }

  public String echo70(String echo) {
    return echo;
  }

  public String echo71(String echo) {
    return echo;
  }

  public String echo72(String echo) {
    return echo;
  }

  public String echo73(String echo) {
    return echo;
  }

  public String echo74(String echo) {
    return echo;
  }

  public String echo75(String echo) {
    return echo;
  }

  public String echo76(String echo) {
    return echo;
  }

  public String echo77(String echo) {
    return echo;
  }

  public String echo78(String echo) {
    return echo;
  }

  public String echo79(String echo) {
    return echo;
  }

  public String echo80(String echo) {
    return echo;
  }

  public String echo81(String echo) {
    return echo;
  }

  public String echo82(String echo) {
    return echo;
  }

  public String echo83(String echo) {
    return echo;
  }

  public String echo84(String echo) {
    return echo;
  }

  public String echo85(String echo) {
    return echo;
  }

  public String echo86(String echo) {
    return echo;
  }

  public String echo87(String echo) {
    return echo;
  }

  public String echo88(String echo) {
    return echo;
  }

  public String echo89(String echo) {
    return echo;
  }

  public String echo90(String echo) {
    return echo;
  }

  public String echo91(String echo) {
    return echo;
  }

  public String echo92(String echo) {
    return echo;
  }

  public String echo93(String echo) {
    return echo;
  }

  public String echo94(String echo) {
    return echo;
  }

  public String echo95(String echo) {
    return echo;
  }

  public String echo96(String echo) {
    return echo;
  }

  public String echo97(String echo) {
    return echo;
  }

  public String echo98(String echo) {
    return echo;
  }

  public String echo99(String echo) {
    return echo;
  }

  public String echo100(String echo) {
    return echo;
  }

  public String echo101(String echo) {
    return echo;
  }

  public String echo102(String echo) {
    return echo;
  }

  public String echo103(String echo) {
    return echo;
  }

  public String echo104(String echo) {
    return echo;
  }

  public String echo105(String echo) {
    return echo;
  }

  public String echo106(String echo) {
    return echo;
  }

  public String echo107(String echo) {
    return echo;
  }

  public String echo108(String echo) {
    return echo;
  }

  public String echo109(String echo) {
    return echo;
  }

  public String echo110(String echo) {
    return echo;
  }

  public String echo111(String echo) {
    return echo;
  }

  public String echo112(String echo) {
    return echo;
  }

  public String echo113(String echo) {
    return echo;
  }

  public String echo114(String echo) {
    return echo;
  }

  public String echo115(String echo) {
    return echo;
  }

  public String echo116(String echo) {
    return echo;
  }

  public String echo117(String echo) {
    return echo;
  }

  public String echo118(String echo) {
    return echo;
  }

  public String echo119(String echo) {
    return echo;
  }

  public String echo120(String echo) {
    return echo;
  }

  public String echo121(String echo) {
    return echo;
  }

  public String echo122(String echo) {
    return echo;
  }

  public String echo123(String echo) {
    return echo;
  }

  public String echo124(String echo) {
    return echo;
  }

  public String echo125(String echo) {
    return echo;
  }

  public String echo126(String echo) {
    return echo;
  }

  public String echo127(String echo) {
    return echo;
  }

  public String echo128(String echo) {
    return echo;
  }

  public String echo129(String echo) {
    return echo;
  }

  public String echo130(String echo) {
    return echo;
  }

  public String echo131(String echo) {
    return echo;
  }

  public String echo132(String echo) {
    return echo;
  }

  public String echo133(String echo) {
    return echo;
  }

  public String echo134(String echo) {
    return echo;
  }

  public String echo135(String echo) {
    return echo;
  }

  public String echo136(String echo) {
    return echo;
  }

  public String echo137(String echo) {
    return echo;
  }

  public String echo138(String echo) {
    return echo;
  }

  public String echo139(String echo) {
    return echo;
  }

  public String echo140(String echo) {
    return echo;
  }

  public String echo141(String echo) {
    return echo;
  }

  public String echo142(String echo) {
    return echo;
  }

  public String echo143(String echo) {
    return echo;
  }

  public String echo144(String echo) {
    return echo;
  }

  public String echo145(String echo) {
    return echo;
  }

  public String echo146(String echo) {
    return echo;
  }

  public String echo147(String echo) {
    return echo;
  }

  public String echo148(String echo) {
    return echo;
  }

  public String echo149(String echo) {
    return echo;
  }

  public String echo150(String echo) {
    return echo;
  }

  public String echo151(String echo) {
    return echo;
  }

  public String echo152(String echo) {
    return echo;
  }

  public String echo153(String echo) {
    return echo;
  }

  public String echo154(String echo) {
    return echo;
  }

  public String echo155(String echo) {
    return echo;
  }

  public String echo156(String echo) {
    return echo;
  }

  public String echo157(String echo) {
    return echo;
  }

  public String echo158(String echo) {
    return echo;
  }

  public String echo159(String echo) {
    return echo;
  }

  public String echo160(String echo) {
    return echo;
  }

  public String echo161(String echo) {
    return echo;
  }

  public String echo162(String echo) {
    return echo;
  }

  public String echo163(String echo) {
    return echo;
  }

  public String echo164(String echo) {
    return echo;
  }

  public String echo165(String echo) {
    return echo;
  }

  public String echo166(String echo) {
    return echo;
  }

  public String echo167(String echo) {
    return echo;
  }

  public String echo168(String echo) {
    return echo;
  }

  public String echo169(String echo) {
    return echo;
  }

  public String echo170(String echo) {
    return echo;
  }

  public String echo171(String echo) {
    return echo;
  }

  public String echo172(String echo) {
    return echo;
  }

  public String echo173(String echo) {
    return echo;
  }

  public String echo174(String echo) {
    return echo;
  }

  public String echo175(String echo) {
    return echo;
  }

  public String echo176(String echo) {
    return echo;
  }

  public String echo177(String echo) {
    return echo;
  }

  public String echo178(String echo) {
    return echo;
  }

  public String echo179(String echo) {
    return echo;
  }

  public String echo180(String echo) {
    return echo;
  }

  public String echo181(String echo) {
    return echo;
  }

  public String echo182(String echo) {
    return echo;
  }

  public String echo183(String echo) {
    return echo;
  }

  public String echo184(String echo) {
    return echo;
  }

  public String echo185(String echo) {
    return echo;
  }

  public String echo186(String echo) {
    return echo;
  }

  public String echo187(String echo) {
    return echo;
  }

  public String echo188(String echo) {
    return echo;
  }

  public String echo189(String echo) {
    return echo;
  }

  public String echo190(String echo) {
    return echo;
  }

  public String echo191(String echo) {
    return echo;
  }

  public String echo192(String echo) {
    return echo;
  }

  public String echo193(String echo) {
    return echo;
  }

  public String echo194(String echo) {
    return echo;
  }

  public String echo195(String echo) {
    return echo;
  }

  public String echo196(String echo) {
    return echo;
  }

  public String echo197(String echo) {
    return echo;
  }

  public String echo198(String echo) {
    return echo;
  }

  public String echo199(String echo) {
    return echo;
  }

  public String echo200(String echo) {
    return echo;
  }

  public String echo201(String echo) {
    return echo;
  }

  public String echo202(String echo) {
    return echo;
  }

  public String echo203(String echo) {
    return echo;
  }

  public String echo204(String echo) {
    return echo;
  }

  public String echo205(String echo) {
    return echo;
  }

  public String echo206(String echo) {
    return echo;
  }

  public String echo207(String echo) {
    return echo;
  }

  public String echo208(String echo) {
    return echo;
  }

  public String echo209(String echo) {
    return echo;
  }

  public String echo210(String echo) {
    return echo;
  }

  public String echo211(String echo) {
    return echo;
  }

  public String echo212(String echo) {
    return echo;
  }

  public String echo213(String echo) {
    return echo;
  }

  public String echo214(String echo) {
    return echo;
  }

  public String echo215(String echo) {
    return echo;
  }

  public String echo216(String echo) {
    return echo;
  }

  public String echo217(String echo) {
    return echo;
  }

  public String echo218(String echo) {
    return echo;
  }

  public String echo219(String echo) {
    return echo;
  }

  public String echo220(String echo) {
    return echo;
  }

  public String echo221(String echo) {
    return echo;
  }

  public String echo222(String echo) {
    return echo;
  }

  public String echo223(String echo) {
    return echo;
  }

  public String echo224(String echo) {
    return echo;
  }

  public String echo225(String echo) {
    return echo;
  }

  public String echo226(String echo) {
    return echo;
  }

  public String echo227(String echo) {
    return echo;
  }

  public String echo228(String echo) {
    return echo;
  }

  public String echo229(String echo) {
    return echo;
  }

  public String echo230(String echo) {
    return echo;
  }

  public String echo231(String echo) {
    return echo;
  }

  public String echo232(String echo) {
    return echo;
  }

  public String echo233(String echo) {
    return echo;
  }

  public String echo234(String echo) {
    return echo;
  }

  public String echo235(String echo) {
    return echo;
  }

  public String echo236(String echo) {
    return echo;
  }

  public String echo237(String echo) {
    return echo;
  }

  public String echo238(String echo) {
    return echo;
  }

  public String echo239(String echo) {
    return echo;
  }

  public String echo240(String echo) {
    return echo;
  }

  public String echo241(String echo) {
    return echo;
  }

  public String echo242(String echo) {
    return echo;
  }

  public String echo243(String echo) {
    return echo;
  }

  public String echo244(String echo) {
    return echo;
  }

  public String echo245(String echo) {
    return echo;
  }

  public String echo246(String echo) {
    return echo;
  }

  public String echo247(String echo) {
    return echo;
  }

  public String echo248(String echo) {
    return echo;
  }

  public String echo249(String echo) {
    return echo;
  }

  public String echo250(String echo) {
    return echo;
  }

  public String echo251(String echo) {
    return echo;
  }

  public String echo252(String echo) {
    return echo;
  }

  public String echo253(String echo) {
    return echo;
  }

  public String echo254(String echo) {
    return echo;
  }

  public String echo255(String echo) {
    return echo;
  }

  public String echo256(String echo) {
    return echo;
  }

  public String echo257(String echo) {
    return echo;
  }

  public String echo258(String echo) {
    return echo;
  }

  public String echo259(String echo) {
    return echo;
  }

  public String echo260(String echo) {
    return echo;
  }

  public String echo261(String echo) {
    return echo;
  }

  public String echo262(String echo) {
    return echo;
  }

  public String echo263(String echo) {
    return echo;
  }

  public String echo264(String echo) {
    return echo;
  }

  public String echo265(String echo) {
    return echo;
  }

  public String echo266(String echo) {
    return echo;
  }

  public String echo267(String echo) {
    return echo;
  }

  public String echo268(String echo) {
    return echo;
  }

  public String echo269(String echo) {
    return echo;
  }

  public String echo270(String echo) {
    return echo;
  }

  public String echo271(String echo) {
    return echo;
  }

  public String echo272(String echo) {
    return echo;
  }

  public String echo273(String echo) {
    return echo;
  }

  public String echo274(String echo) {
    return echo;
  }

  public String echo275(String echo) {
    return echo;
  }

  public String echo276(String echo) {
    return echo;
  }

  public String echo277(String echo) {
    return echo;
  }

  public String echo278(String echo) {
    return echo;
  }

  public String echo279(String echo) {
    return echo;
  }

  public String echo280(String echo) {
    return echo;
  }

  public String echo281(String echo) {
    return echo;
  }

  public String echo282(String echo) {
    return echo;
  }

  public String echo283(String echo) {
    return echo;
  }

  public String echo284(String echo) {
    return echo;
  }

  public String echo285(String echo) {
    return echo;
  }

  public String echo286(String echo) {
    return echo;
  }

  public String echo287(String echo) {
    return echo;
  }

  public String echo288(String echo) {
    return echo;
  }

  public String echo289(String echo) {
    return echo;
  }

  public String echo290(String echo) {
    return echo;
  }

  public String echo291(String echo) {
    return echo;
  }

  public String echo292(String echo) {
    return echo;
  }

  public String echo293(String echo) {
    return echo;
  }

  public String echo294(String echo) {
    return echo;
  }

  public String echo295(String echo) {
    return echo;
  }

  public String echo296(String echo) {
    return echo;
  }

  public String echo297(String echo) {
    return echo;
  }

  public String echo298(String echo) {
    return echo;
  }

  public String echo299(String echo) {
    return echo;
  }

}