Merge pull request #6828 from jlarroque/master

BAEL-2832: Check if a String contains a Substring

java-strings-2/pom.xml

@@ -0,0 +1,150 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>java-strings-2</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>java-strings-2</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>commons-io</groupId>
+            <artifactId>commons-io</artifactId>
+            <version>${commons-io.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>log4j</groupId>
+            <artifactId>log4j</artifactId>
+            <version>${log4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>commons-codec</groupId>
+            <artifactId>commons-codec</artifactId>
+            <version>${commons-codec.version}</version>
+        </dependency>
+        <!-- test scoped -->
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.ibm.icu</groupId>
+            <artifactId>icu4j</artifactId>
+            <version>${icu4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.vdurmont</groupId>
+            <artifactId>emoji-java</artifactId>
+            <version>${emoji-java.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>${junit-jupiter-api.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-library</artifactId>
+            <version>${hamcrest-library.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <!-- Added for password generation -->
+        <dependency>
+            <groupId>org.passay</groupId>
+            <artifactId>passay</artifactId>
+            <version>${passay.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-text</artifactId>
+            <version>${commons-text.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.ahocorasick</groupId>
+            <artifactId>ahocorasick</artifactId>
+            <version>${ahocorasick.version}</version>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <finalName>java-strings-2</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${java.version}</source>
+                    <target>${java.version}</target>
+                    <compilerArgument>-parameters</compilerArgument>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <!-- util -->
+        <commons-lang3.version>3.8.1</commons-lang3.version>
+        <commons-codec.version>1.10</commons-codec.version>
+        <!-- testing -->
+        <assertj.version>3.6.1</assertj.version>
+        <jmh-core.version>1.19</jmh-core.version>
+        <icu4j.version>61.1</icu4j.version>
+        <guava.version>27.0.1-jre</guava.version>
+        <emoji-java.version>4.0.0</emoji-java.version>
+        <junit-jupiter-api.version>5.3.1</junit-jupiter-api.version>
+        <hamcrest-library.version>1.3</hamcrest-library.version>
+        <passay.version>1.3.1</passay.version>
+        <commons-text.version>1.4</commons-text.version>
+        <ahocorasick.version>0.4.0</ahocorasick.version>
+    </properties>
+
+</project>

java-strings-2/src/main/java/com/baeldung/string/search/performance/SubstringSearchPerformanceComparison.java

@@ -0,0 +1,58 @@
+package com.baeldung.string.search.performance;
+
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+
+import org.apache.commons.lang3.StringUtils;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+
+/**
+ * Based on https://github.com/tedyoung/indexof-contains-benchmark
+ */
+@Fork(5)
+@State(Scope.Benchmark)
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+public class SubstringSearchPerformanceComparison {
+
+    private String message;
+
+    private Pattern pattern;
+
+    public static void main(String[] args) throws Exception {
+        org.openjdk.jmh.Main.main(args);
+    }
+
+    @Setup
+    public void setup() {
+        message = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum";
+        pattern = Pattern.compile("(?<!\\S)" + "eiusmod" + "(?!\\S)");
+    }
+
+    @Benchmark
+    public int indexOf() {
+        return message.indexOf("eiusmod");
+    }
+
+    @Benchmark
+    public boolean contains() {
+        return message.contains("eiusmod");
+    }
+
+    @Benchmark
+    public boolean containsStringUtilsIgnoreCase() {
+        return StringUtils.containsIgnoreCase(message, "eiusmod");
+    }
+
+    @Benchmark
+    public boolean searchWithPattern() {
+        return pattern.matcher(message).find();
+    }
+}

java-strings-2/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>

java-strings-2/src/test/java/com/baeldung/string/search/SubstringSearch.java

@@ -0,0 +1,70 @@
+package com.baeldung.string.search;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.apache.commons.lang3.StringUtils;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * BAEL-2832: Different ways to check if a Substring could be found in a String.
+ */
+public class SubstringSearch {
+
+    @Test
+    public void searchSubstringWithIndexOf() {
+        Assert.assertEquals(9, "Bohemian Rhapsodyan".indexOf("Rhap"));
+
+        // indexOf will return -1, because it's case sensitive
+        Assert.assertEquals(-1, "Bohemian Rhapsodyan".indexOf("rhap"));
+
+        // indexOf will return 9, because it's all lowercase
+        Assert.assertEquals(9, "Bohemian Rhapsodyan".toLowerCase()
+            .indexOf("rhap"));
+
+        // it will return 6, because it's the first occurrence. Sorry Queen for being blasphemic
+        Assert.assertEquals(6, "Bohemian Rhapsodyan".indexOf("an"));
+    }
+
+    @Test
+    public void searchSubstringWithContains() {
+        Assert.assertTrue("Hey Ho, let's go".contains("Hey"));
+
+        // contains will return false, because it's case sensitive
+        Assert.assertFalse("Hey Ho, let's go".contains("hey"));
+
+        // contains will return true, because it's all lowercase
+        Assert.assertTrue("Hey Ho, let's go".toLowerCase().contains("hey"));
+
+        // contains will return false, because 'jey' can't be found
+        Assert.assertFalse("Hey Ho, let's go".contains("jey"));
+    }
+
+    @Test
+    public void searchSubstringWithStringUtils() {
+        Assert.assertTrue(StringUtils.containsIgnoreCase("Runaway train", "train"));
+
+        // it will also be true, because ignores case ;)
+        Assert.assertTrue(StringUtils.containsIgnoreCase("Runaway train", "Train"));
+    }
+
+    @Test
+    public void searchUsingPattern() {
+
+        // We create the Pattern first
+        Pattern pattern = Pattern.compile("(?<!\\S)" + "road" + "(?!\\S)");
+
+        // We need to create the Matcher after
+        Matcher matcher = pattern.matcher("Hit the road Jack");
+
+        // find will return true when the first match is found
+        Assert.assertTrue(matcher.find());
+
+        // We will create a different matcher with a different text
+        matcher = pattern.matcher("and don't you come back no more");
+
+        // find will return false, because 'road' can't be find as a substring
+        Assert.assertFalse(matcher.find());
+    }
+}

java-strings-2/src/test/resources/.gitignore

@@ -0,0 +1,13 @@
+*.class
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear

pom.xml

@@ -462,6 +462,7 @@
                 <module>java-streams</module>
                 <module>java-streams-2</module>
                 <module>java-strings</module>
+                <module>java-strings-2</module>
                 <module>java-vavr-stream</module>
                 <module>java-websocket</module>
                 <module>javafx</module>
@@ -1134,6 +1135,7 @@
                 <module>java-streams</module>
                 <module>java-streams-2</module>
                 <module>java-strings</module>
+                <module>java-strings-2</module>
                 <module>java-vavr-stream</module>
                 <module>java-websocket</module>
                 <module>javafx</module>