1 /*
   2  * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.openjdk.bench.java.lang;
  24 
  25 import org.openjdk.jmh.annotations.Benchmark;
  26 import org.openjdk.jmh.annotations.BenchmarkMode;
  27 import org.openjdk.jmh.annotations.Mode;
  28 import org.openjdk.jmh.annotations.OutputTimeUnit;
  29 import org.openjdk.jmh.annotations.Scope;
  30 import org.openjdk.jmh.annotations.Setup;
  31 import org.openjdk.jmh.annotations.State;
  32 import org.openjdk.jmh.infra.Blackhole;
  33 
  34 import java.util.Random;
  35 import java.util.concurrent.TimeUnit;
  36 
  37 /**
  38  * Trivial String concatenation benchmark.
  39  */
  40 @BenchmarkMode(Mode.AverageTime)
  41 @OutputTimeUnit(TimeUnit.NANOSECONDS)
  42 @State(Scope.Thread)
  43 public class StringConcat {
  44 
  45     public int intValue = 4711;
  46 
  47     public String stringValue = String.valueOf(intValue);
  48 
  49     public Object objectValue = Long.valueOf(intValue);
  50 
  51     public boolean boolValue = true;
  52 
  53     public byte byteValue = (byte)-128;
  54 
  55     @Benchmark
  56     public String concatConstInt() {
  57         return "string" + intValue;
  58     }
  59 
  60     @Benchmark
  61     public String concatConstString() {
  62         return "string" + stringValue;
  63     }
  64 
  65     @Benchmark
  66     public String concatMethodConstString() {
  67         return "string".concat(stringValue);
  68     }
  69 
  70     @Benchmark
  71     public String concatConstIntConstInt() {
  72         return "string" + intValue + "string" + intValue;
  73     }
  74 
  75     @Benchmark
  76     public String concatConstStringConstInt() {
  77         return "string" + stringValue + "string" + intValue;
  78     }
  79 
  80     @Benchmark
  81     public String concatConst4String() {
  82         return "string" + stringValue + stringValue + stringValue + stringValue;
  83     }
  84 
  85     @Benchmark
  86     public String concat4String() {
  87         return stringValue + stringValue + stringValue + stringValue;
  88     }
  89 
  90     @Benchmark
  91     public String concatConst2String() {
  92         return "string" + stringValue + stringValue;
  93     }
  94 
  95     @Benchmark
  96     public String concatConstBoolByte() {
  97         return "string" + boolValue + byteValue;
  98     }
  99 
 100     @Benchmark
 101     public String concatConst6String() {
 102         return "string" + stringValue + stringValue + stringValue + stringValue + stringValue + stringValue;
 103     }
 104 
 105     @Benchmark
 106     public String concat6String() {
 107         return stringValue + stringValue + stringValue + stringValue + stringValue + stringValue;
 108     }
 109 
 110     @Benchmark
 111     public String concatConst6Object() {
 112         return "string" + objectValue + objectValue + objectValue + objectValue + objectValue + objectValue;
 113     }
 114 
 115 }