Maven coordinates: ```xml <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.15</version> </dependency> ``` Apache Commons Codec is a Java library that provides a set of universal encoding and decoding functions, including Base64, MD5, SHA, and more. Among them, Base64 is an encoding method that converts binary data into ASCII text format. The example code is as follows: ```java import org.apache.commons.codec.binary.Base64; public class Base64Example { public static void main(String[] args) { //Raw binary data byte[] binaryData = { 0x01, 0x02, 0x03, 0x04, 0x05 }; //Perform Base64 encoding String encodedString = Base64.encodeBase64String(binaryData); System. out. println ("Base64 encoding result:"+encodedString); //Perform Base64 decoding byte[] decodedData = Base64.decodeBase64(encodedString); System. out. print ("Base64 decoding result:"); for (byte b : decodedData) { System.out.print(String.format("0x%02X ", b)); } } } ``` Output results: ``` Base64 encoding result: AQIDBAU= Base64 decoding result: 0x01 0x02 0x03 0x04 0x05 ``` Summary: The Base64 class of the Apache Commons Codec library allows for easy conversion between binary data and ASCII text formats. The Base64. encodeBase64String method can be used for Base64 encoding, and the Base64. decodeBase64 method can be used for Base64 decoding.

The Maven coordinates of the dependent class library are: ``` <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.15</version> </dependency> ``` Apache Commons Codec is a Java library for encoding and decoding, providing implementations of various common encoding algorithms, including URL encoding. Its goal is to provide a set of easy-to-use tools that developers can easily perform encoding and decoding operations without worrying about the specific implementation details of the algorithm. The following is a complete example of using Apache Commons Codec to implement URL encoding/decoding: ```java import org.apache.commons.codec.CharEncoding; import org.apache.commons.codec.net.URLCodec; import java.io.UnsupportedEncodingException; public class UrlEncoderDecoderExample { public static void main(String[] args) throws UnsupportedEncodingException { String input = "This is a sample input with special characters: !@#$%^&*()"; //URL encoding URLCodec urlCodec = new URLCodec(CharEncoding.UTF_8); String encodedUrl = urlCodec.encode(input); System.out.println("Encoded URL: " + encodedUrl); //URL decoding String decodedUrl = urlCodec.decode(encodedUrl); System.out.println("Decoded URL: " + decodedUrl); } } ``` In the above code, we first created a 'URLCodec' object and specified the use of UTF-8 Character encoding. Then, use the 'encode' method to encode the input string and print the encoded URL string. Next, use the 'decode' method to decode the encoded URL string and print the decoded string. Finally, summarize the steps for implementing URL encoding/decoding using Apache Commons Codec: 1. Import Apache Commons Codec Maven dependencies. 2. Create a 'URLCodec' object and specify the Character encoding. 3. Use the 'encode' method to encode the URL of the string to be encoded. 4. Use the 'decode' method to decode the encoded URL string.

Maven coordinates: ``` <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.15</version> </dependency> ``` Apache Commons Codec is a Java based string encoding/decoding tool library. It provides a series of common encoding and decoding algorithms and string conversion functions, including Base64, Hex, HTML entity encoding, and so on. In this example, we will use Apache Commons Codec to implement HTML encoding/decoding, converting special characters into HTML entity format. Firstly, we need to import the required classes: ```java import org.apache.commons.codec.StringEscapeUtils; ``` Next, we can use the 'StringEscapeUtils' class for HTML encoding/decoding. Here is a complete example: ```java public class HtmlEncodingExample { public static void main(String[] args) { String input = "<h1>Hello, world!</h1>"; System.out.println("Input: " + input); //Encode HTML String encoded = StringEscapeUtils.escapeHtml(input); System.out.println("Encoded: " + encoded); //Perform HTML decoding String decoded = StringEscapeUtils.unescapeHtml(encoded); System.out.println("Decoded: " + decoded); } } ``` Running the above code will output the following content: ``` Input: <h1>Hello, world!</h1> Encoded: <h1>Hello, world!</h1> Decoded: <h1>Hello, world!</h1> ``` In this example, we first defined a string containing special characters. Then, we use the 'StringEscapeUtils. escapeHtml' method to HTML encode the string and decode it using the 'StringEscapeUtils. unescapeHtml' method. Summary: Apache Commons Codec is a powerful Java string encoding/decoding tool library that provides multiple encoding and decoding algorithms and string conversion functions. Using the 'StringEscapeUtils' class of this library, we can easily encode/decode HTML and convert special characters into HTML entity format.

Apache Commons Codec is a Java library that provides a series of encoding and decoding implementations, including Hex encoding and decoding. It is part of the Apache Commons project and can be used to manage dependencies through Apache Maven. 1. Maven coordinates: ```xml <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.15</version> </dependency> ``` 2. Brief introduction: Apache Commons Codec provides a variety of encoding and decoding implementations, including hex encoding and decoding (Hex), Base64 encoding and decoding, URL encoding and decoding, HTML encoding and decoding, and so on. Hex encoding is used to convert binary data into strings in hexadecimal format, which is one of the common data conversion methods. 3. Complete sample code: ```java import org.apache.commons.codec.DecoderException; import org.apache.commons.codec.binary.Hex; public class HexExample { public static void main(String[] args) { byte[] binaryData = {0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x2C, 0x20, 0x57, 0x6F, 0x72, 0x6C, 0x64}; // Hello, World //Encoding: converting binary data to hexadecimal strings String hexString = Hex.encodeHexString(binaryData); System. out. println ("Hex encoding string:"+hexString); //Decoding: converting hexadecimal strings to binary data try { byte[] decodedData = Hex.decodeHex(hexString); String decodedString = new String(decodedData); System. out. println ("Decoded string:"+decodedString); } catch (DecoderException e) { System. out. println ("Decoding failed:"+e.getMessage ()); } } } ``` 4. Summary: This article introduces how to use the Hex class of Apache Commons Codec for Hex encoding and decoding. Firstly, the dependency of Apache Commons Codec was added through Maven; Then, binary data can be encoded into hexadecimal strings through the 'encodeHexString' method of the Hex class; Finally, the hex string can be decoded into binary data through the 'decodeHex' method of the Hex class. Using Apache Commons Codec makes it easy to perform various encoding and decoding operations, which is very practical.

Apache Commons Codec is an open source Java class library that provides a set of easy-to-use encoding and decoding tools, including commonly used encoding algorithms such as Base64, MD5, SHA, etc. Before using Apache Commons Codec to implement MD5 encryption, it is necessary to add a dependency on Apache Commons Codec in the pom.xml file of the project. The following are the Maven coordinates of Apache Commons Codec: ```xml <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.15</version> </dependency> ``` Next, we will demonstrate how to implement MD5 encryption using Apache Commons Codec through a complete example. Firstly, import the required classes: ```java import org.apache.commons.codec.digest.DigestUtils; ``` Then, use the following code for MD5 encryption: ```java String input = "Hello World"; String md5Hex = DigestUtils.md5Hex(input); System. out. println ("MD5 encryption result:"+md5Hex); ``` Running the above code will output the following results: ``` MD5 encryption result: ed076287532e86365e841e92bfc50d8c ``` Finally, summarize the above examples: By using the 'DigestUtils. md5Hex()' method of Apache Commons Codec, we can easily achieve MD5 encryption of strings. Apache Commons Codec provides a series of encoding and decoding tools to facilitate the operation of commonly used encoding algorithms in Java programs. It is simple to use, easy to integrate, and has good performance.

Apache Commons Codec is a Java class library that provides implementations of common encoding and decoding algorithms, including BASE64, SHA, MD5, and more. It provides developers with a simple and convenient way to encode and encrypt data. The Maven coordinates of this class library are as follows: ``` <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.15</version> </dependency> ``` The following is a complete example of using Apache Commons Codec to implement SHA encryption: ```java import org.apache.commons.codec.digest.DigestUtils; public class SHAExample { public static void main(String[] args) { String input = "Hello World"; //Use SHA1 algorithm for encryption String sha1 = DigestUtils.sha1Hex(input); System.out.println("SHA1: " + sha1); //Encrypt using SHA256 algorithm String sha256 = DigestUtils.sha256Hex(input); System.out.println("SHA256: " + sha256); //Encrypt using SHA512 algorithm String sha512 = DigestUtils.sha512Hex(input); System.out.println("SHA512: " + sha512); } } ``` Executing the above code will output the following results: ``` SHA1: 2ef7bde608ce5404e97d5f042f95f89f1c232871 SHA256: 943a702d06f34599aee1f8da8ef9f7296031d699cc560ca44a5b0344a15ce3a4 SHA512: b7e23ec29af22b0b4e41da31e868d57226121c84e62c0511f85e6390388aaf3e2a5df6b08c7c6fa85904aee241cf7b015461f50b8bbf9bc82f9888e95b6158c3 ``` Summary: Apache Commons Codec is a very convenient Java class library that provides implementations of many commonly used encoding and encryption algorithms. When using SHA encryption, we can use the static method of the DigestUtils class to encrypt and obtain the encryption results. The use of this class library is simple and clear, and can be used by adding dependencies through Maven coordinates.

The Maven coordinates of the dependent class library are: ```xml <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.15</version> </dependency> ``` Apache Commons Codec is an open source Java class library that provides various encoding and decoding methods, including basic binary, hexadecimal, URL, Base64, etc. It also provides tool classes for implementing different hash and validation algorithms, such as MD5, SHA-1, CRC, etc. The following is a complete example of using Apache Commons Codec to implement CRC verification: ```java import org.apache.commons.codec.digest.CRC32; public class CRC32Checksum { public static void main(String[] args) { //Data to calculate checksum byte[] data = "Hello, World!".getBytes(); //Create CRC32 object CRC32 crc32 = new CRC32(); //Update checksum crc32.update(data); //Obtain checksum value long checksum = crc32.getValue(); System.out.println("CRC32 Checksum: " + checksum); } } ``` In the above example, we use the 'CRC32' class to calculate the CRC checksum of the data. Firstly, create a 'CRC32' object, then use the 'update' method to add data to the checksum, and finally obtain the checksum value through the 'getValue' method. Summary: This article introduces how to use Apache Commons Codec to implement CRC verification to detect the integrity of data transmission. By introducing relevant Maven dependencies and using the 'CRC32' class, we can conveniently calculate the CRC checksum of the data.

Maven coordinates: ``` <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.15</version> </dependency> ``` Apache Commons Codec is an open source Java class library used to solve some common encoding and decoding problems. It provides a series of tool classes for processing binary data, Character encoding, data checksum digest, encryption and decryption and other functions. Metaphone is a Character encoding algorithm used to convert English words into phonetic symbols. It is based on English pronunciation rules and is used to match similar English words. Metaphone encoding is not unique, but in some cases it can be used as an effective tool for string matching. The following is a complete example of using Apache Commons Codec to implement Metaphone encoding to convert English words into phonetic format: ```java import org.apache.commons.codec.language.Metaphone; public class MetaphoneExample { public static void main(String[] args) { Metaphone metaphone = new Metaphone(); String word = "hello"; String encodedWord = metaphone.encode(word); System.out.println("Original word: " + word); System.out.println("Encoded word: " + encodedWord); } } ``` Output results: ``` Original word: hello Encoded word: HL ``` In the above example, we first created a Metaphone object and then used the 'encode()' method to convert the specified English word into a Metaphone encoding format. Finally, we print out the original and encoded words. Summary: Apache Commons Codec provides a Metaphone class for converting English words into phonetic format. This is a very convenient tool that can be used to handle English string matching problems. Using Metaphone encoding can also improve the accuracy of string matching by reducing variations and normalizing characters.

Apache Commons Codec is a Java class library that provides various algorithm implementations for encoding and decoding, such as Base64, MD5, SHA, and Soundex. It can be used for encoding and decoding various binary and textual data. The Maven coordinates of the dependent class library are: ```xml <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.15</version> </dependency> ``` Soundex is an algorithm used to convert English words into a format similar to a phone number. It is mainly encoded based on the pronunciation of words, and words with similar pronunciations will have the same encoding. The result of Soundex encoding is a string of length 4. The following is a complete example of using Apache Commons Codec to implement Soundex encoding: ```java import org.apache.commons.codec.language.Soundex; public class SoundexExample { public static void main(String[] args) { String word = "hello"; Soundex soundex = new Soundex(); String soundexCode = soundex.encode(word); System.out.println("Word: " + word); System.out.println("Soundex Code: " + soundexCode); } } ``` Output results: ``` Word: hello Soundex Code: H400 ``` In the above example, a Soundex object was first created. Then, the 'encode' method was used to encode the specified English words, resulting in the corresponding Soundex encoding. Finally, output the original words and encoding results to the console. Summary: By using the Soundex class of Apache Commons Codec, we can easily convert English words into a format similar to a phone number. Soundex encoding can be used to process words with similar pronunciation in text data for some text processing operations. Using Apache Commons Codec can simplify encoding and decoding operations.