以下是代码:
package misc;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.github.benmanes.caffeine.cache.Cache;
import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.RunnerException;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;
import java.util.function.Function;
@State(Scope.Thread)
public class caff {
public Cache<String, Integer> cache = Caffeine.newBuilder().build();
public ArrayList<String> k = new ArrayList<>();
int p;
@Setup(Level.Iteration)
public void setup(){
k.clear();
//cache.clear();
for(int m=0;m<1000;m++){
int j=ThreadLocalRandom.current().nextInt(0,10000);
String jk=Integer.toString(j);
k.add(jk);
cache.put(jk,j);
}
}
@Benchmark
@BenchmarkMode(Mode.Throughput)
@OperationsPerInvocation(10)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@Warmup(iterations = 3)
@Measurement(iterations = 100)
public void putKey() {
int n= ThreadLocalRandom.current().nextInt(0,10000);
String nk=Integer.toString(n);
k.add(nk);
cache.put(nk,n);
}
@Benchmark
@BenchmarkMode(Mode.Throughput)
@OperationsPerInvocation(10)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@Warmup(iterations = 3)
@Measurement(iterations = 100)
public void getKey() {
String j;
p = ThreadLocalRandom.current().nextInt(0, 10000);
p = p % k.size();
j = k.get(p);
cache.get(j);
}
public static void main(String[] args) throws RunnerException {
Options opt = new OptionsBuilder()
.include(".*" + caff.class.getSimpleName() + ".*")
.forks(1)
//.addProfiler(GCProfiler.class)
.jvmArgs("-Xmx1025M")
.build();
new Runner(opt).run();
}
}
问题是cache.get()给出了错误:
Error:(60, 14) java: method get in interface com.github.benmanes.caffeine.cache.Cache<K,V> cannot be applied to given types;
required: java.lang.String,java.util.function.Function<? super java.lang.String,? extends java.lang.Integer>
found: java.lang.String
reason: actual and formal argument lists differ in length
get()方法的确切期望是什么?我找不到任何例子,我也不明白为什么它需要另外一个功能。