Merge pull request #8125 from eugenp/revert-8119-BAEL-3275-2

Revert "BAEL-3275: Using blocking queue for pub-sub"

java-strings/src/main/java/com/baeldung/java9/compactstring/CompactStringDemo.java

@@ -0,0 +1,24 @@
+package com.baeldung.java9.compactstring;
+
+import java.util.List;
+import static java.util.stream.Collectors.toList;
+import java.util.stream.IntStream;
+
+public class CompactStringDemo {
+
+    public static void main(String[] args) {
+        long startTime = System.currentTimeMillis();
+        List strings = IntStream.rangeClosed(1, 10_000_000)
+          .mapToObj(Integer::toString).collect(toList());
+        long totalTime = System.currentTimeMillis() - startTime;
+        System.out.println("Generated " + strings.size() + " strings in " 
+          + totalTime + " ms.");
+
+        startTime = System.currentTimeMillis();
+        String appended = (String) strings.stream().limit(100_000)
+          .reduce("", (left, right) -> left.toString() + right.toString());
+        totalTime = System.currentTimeMillis() - startTime;
+        System.out.println("Created string of length " + appended.length() 
+          + " in " + totalTime + " ms.");
+    }
+}

java-strings/src/main/java/com/baeldung/string/StringPerformance.java

@@ -0,0 +1,196 @@
+package com.baeldung.string;
+
+import com.google.common.base.Splitter;
+import org.apache.commons.lang3.StringUtils;
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.StringTokenizer;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+
+@BenchmarkMode(Mode.SingleShotTime)
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+@Measurement(batchSize = 100000, iterations = 10)
+@Warmup(batchSize = 100000, iterations = 10)
+@State(Scope.Thread)
+public class StringPerformance {
+
+    protected String baeldung = "baeldung";
+    protected String longString = "Hello baeldung, I am a bit longer than other Strings";
+    protected String formatString = "hello %s, nice to meet you";
+    protected String formatDigit = "%d";
+    protected String emptyString = " ";
+    protected String result = "";
+
+    protected int sampleNumber = 100;
+
+    protected Pattern spacePattern = Pattern.compile(emptyString);
+    protected Pattern longPattern = Pattern.compile(longString);
+    protected List<String> stringSplit = new ArrayList<>();
+    protected List<String> stringTokenizer = new ArrayList<>();
+
+    @Benchmark
+    public String benchmarkStringDynamicConcat() {
+        result += baeldung;
+        return result;
+    }
+
+    @Benchmark
+    public StringBuilder  benchmarkStringBuilder() {
+        StringBuilder stringBuilder = new StringBuilder(result);
+        stringBuilder.append(baeldung);
+        return stringBuilder;
+    }
+
+    @Benchmark
+    public StringBuffer benchmarkStringBuffer() {
+        StringBuffer stringBuffer = new StringBuffer(result);
+        stringBuffer.append(baeldung);
+        return stringBuffer;
+    }
+
+    @Benchmark
+    public String benchmarkStringConstructor() {
+        String result = new String("baeldung");
+        return result;
+    }
+
+    @Benchmark
+    public String benchmarkStringLiteral() {
+        String result = "baeldung";
+        return result;
+    }
+
+    @Benchmark
+    public String benchmarkStringFormat_s() {
+        return String.format(formatString, baeldung);
+    }
+
+    @Benchmark
+    public String benchmarkStringConcat() {
+        result = result.concat(baeldung);
+        return result;
+    }
+
+    @Benchmark
+    public String benchmarkStringIntern() {
+        return baeldung.intern();
+    }
+
+    @Benchmark
+    public String benchmarkStringReplace() {
+        return longString.replace("average", " average !!!");
+    }
+
+    @Benchmark
+    public String benchmarkStringUtilsReplace() {
+        return StringUtils.replace(longString, "average", " average !!!");
+    }
+
+    @Benchmark
+    public List<String> benchmarkGuavaSplitter() {
+        return Splitter.on(" ").trimResults()
+                .omitEmptyStrings()
+                .splitToList(longString);
+    }
+
+    @Benchmark
+    public String [] benchmarkStringSplit() {
+        return longString.split(emptyString);
+    }
+
+    @Benchmark
+    public String [] benchmarkStringSplitPattern() {
+        return spacePattern.split(longString, 0);
+    }
+
+    @Benchmark
+    public List benchmarkStringTokenizer() {
+        StringTokenizer st = new StringTokenizer(longString);
+        while (st.hasMoreTokens()) {
+            stringTokenizer.add(st.nextToken());
+        }
+        return stringTokenizer;
+    }
+
+    @Benchmark
+    public List benchmarkStringIndexOf() {
+        int pos = 0, end;
+        while ((end = longString.indexOf(' ', pos)) >= 0) {
+            stringSplit.add(longString.substring(pos, end));
+            pos = end + 1;
+        }
+        return stringSplit;
+    }
+
+    @Benchmark
+    public String benchmarkIntegerToString() {
+        return Integer.toString(sampleNumber);
+    }
+
+    @Benchmark
+    public String benchmarkStringValueOf() {
+        return String.valueOf(sampleNumber);
+    }
+
+
+    @Benchmark
+    public String benchmarkStringConvertPlus() {
+        return sampleNumber + "";
+    }
+
+        @Benchmark
+    public String benchmarkStringFormat_d() {
+        return String.format(formatDigit, sampleNumber);
+    }
+
+    @Benchmark
+    public boolean benchmarkStringEquals() {
+        return longString.equals(baeldung);
+    }
+
+
+    @Benchmark
+    public boolean benchmarkStringEqualsIgnoreCase() {
+        return longString.equalsIgnoreCase(baeldung);
+    }
+
+    @Benchmark
+    public boolean benchmarkStringMatches() {
+        return longString.matches(baeldung);
+    }
+
+    @Benchmark
+    public boolean benchmarkPrecompiledMatches() {
+        return longPattern.matcher(baeldung).matches();
+    }
+
+    @Benchmark
+    public int benchmarkStringCompareTo() {
+        return longString.compareTo(baeldung);
+    }
+
+    @Benchmark
+    public boolean benchmarkStringIsEmpty() {
+        return longString.isEmpty();
+    }
+
+    @Benchmark
+    public boolean benchmarkStringLengthZero() {
+        return longString.length() == 0;
+    }
+
+    public static void main(String[] args) throws Exception {
+        Options options = new OptionsBuilder()
+                .include(StringPerformance.class.getSimpleName()).threads(1)
+                .forks(1).shouldFailOnError(true)
+                .shouldDoGC(true)
+                .jvmArgs("-server").build();
+        new Runner(options).run();
+    }
+}

java-strings/src/main/resources/data.csv

@@ -0,0 +1,3 @@
+1|IND|India
+2|MY|Malaysia
+3|AU|Australia

java-strings/src/main/resources/logback.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>