Escape Character Utility for URL and JSON data – Feel free to use in your Java Project

What is escape character in Java?

Mainly escape characters are the characters which replaces existing character with new & provided character which works best without throwing any error at runtime.

Also, it’s required in order for inter systems/process transmission, i.e. same char works for C++, Java, etc programming language.

In this tutorial we will go over two Escape Character Utilities.

1. URLEscapeUtil
2. JSONEscapeUtil

Also this tutorial will help you if you have below questions:

• Java escape characters in string
• Which characters need to be escaped on HTML
• What does escape char means in java
• Java escape characters in string
• How do I escape a String for Java?
• Escape Sequences in Java with Examples

Let’s get started:

1. Create class CrunchifyEscapeCharUtility.java
2. Create method crunchifyURLEscapeUtil(String s) – which returns String with escape character in provided URL
3. Create method crunchifyJSONEscapeUtil(String s) – which returns String with escape character in provided JSON
4. In Main() –
   1. we will read the JSON data from file
   2. provide file name is Crunchify_Escape_Util.txt
5. We use java.net.URLEncoder to add URL escape char

In Java when we encode a String, the following rules apply:

Here is a Crunchify_Escape_Util.txt file content. Please put it into your laptop/desktop and update path location in program.

{
    "founder": "App Shah",
    "blogURL": "https://crunchify.com",
    "twitter": "https://twitter.com/Crunchify",
    "social": {
        "facebook": "http://facebook.com/Crunchify",
        "pinterest": "https://www.pinterest.com/Crunchify/crunchify-articles”,
        "rss": "https://crunchify.com/feed/"
    }
}

Option-1: Here is a complete Java Example.

• Create our own Escape JSON and URL methods.

package crunchify.com.tutorials;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.text.StringCharacterIterator;

/**
 * @author Crunchify.com
 * Version: 1.0
 * Program: Escape Character Utility for URL and JSON data - Feel free to use in your Java Project.
 */

public class CrunchifyEscapeCharUtility {

    public static void main(String[] args) {

        // URL Escape Utility
        String crunchifyURL = "https://crunchify.com/this is test";
        crunchifyLog("Sample URL: " + crunchifyURL);
        crunchifyLog("Escaped URL: " + crunchifyURLEscapeUtil(crunchifyURL));

        // JSON Escape Utility
        // We will read file first and then we will do escape char on that
        StringBuilder jsonData = new StringBuilder();
        BufferedReader crunchifyBufferReader = null;
        try {
            String crunchifyLine;
            crunchifyBufferReader = new BufferedReader(
                    new FileReader("/Users/app/Downloads/Crunchify_Escape_Util.txt"));
            while ((crunchifyLine = crunchifyBufferReader.readLine()) != null) {
                jsonData.append(crunchifyLine).append("\n");
            }

            // IOException: Signals that an I/O exception of some sort has occurred.
            // This class is the general class of exceptions produced by failed or interrupted I/O operations.
        } catch (IOException exception) {
            exception.printStackTrace();
        } finally {
            try {
                if (crunchifyBufferReader != null)
                    crunchifyBufferReader.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }

        // Let's print raw JSON file data
        crunchifyLog("\n Sample JSON: " + jsonData.toString().toString());

        // Let's print data after escaping JSON strings
        crunchifyLog("Escaped JSON: " + crunchifyJSONEscapeUtil(jsonData.toString().toString()));

    }

    // Used to ensure that HTTP query strings are in proper form, by escaping special characters such as spaces.
    // Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme
    public static String crunchifyURLEscapeUtil(String crunchifyURL) {
        String crunchifyNewURL;

		// UTF_8: Eight-bit UCS Transformation Format.
		crunchifyNewURL = URLEncoder.encode(crunchifyURL, StandardCharsets.UTF_8);
		return crunchifyNewURL;
    }

    // JSON Escape Utility
    public static String crunchifyJSONEscapeUtil(String crunchifyJSON) {

		// StringBuilder(): Constructs a string builder with no characters in it and an initial capacity of 16 characters.
        final StringBuilder crunchifyNewJSON = new StringBuilder();

        // StringCharacterIterator class iterates over the entire String
        StringCharacterIterator crunchifyIterator = new StringCharacterIterator(crunchifyJSON);

		// current(): Implements CharacterIterator.current() for String.
        char crunchifyChar = crunchifyIterator.current();

        // DONE = \\uffff (not a character)
        while (crunchifyChar != StringCharacterIterator.DONE) {
            if (crunchifyChar == '\"') {
                crunchifyNewJSON.append("\\\"");
            } else if (crunchifyChar == '\t') {
                crunchifyNewJSON.append("\\t");
            } else if (crunchifyChar == '\f') {
                crunchifyNewJSON.append("\\f");
            } else if (crunchifyChar == '\n') {
                crunchifyNewJSON.append("\\n");
            } else if (crunchifyChar == '\r') {
                crunchifyNewJSON.append("\\r");
            } else if (crunchifyChar == '\\') {
                crunchifyNewJSON.append("\\\\");
            } else if (crunchifyChar == '/') {
                crunchifyNewJSON.append("\\/");
            } else if (crunchifyChar == '\b') {
                crunchifyNewJSON.append("\\b");
            } else {

                // Nothing matched - just as text as it is.
				// next(): Implements CharacterIterator.next() for String.
                crunchifyNewJSON.append(crunchifyChar);
            }
            crunchifyChar = crunchifyIterator.next();
        }
        return crunchifyNewJSON.toString();
    }

    // Simple log utility
    private static void crunchifyLog(String crunchifyData) {

		System.out.println(crunchifyData);
    }

}

Eclipse Console Output:

Sample URL: https://crunchify.com/this is test
Escaped URL: https%3A%2F%2Fcrunchify.com%2Fthis+is+test

 Sample JSON: {
    "founder": "App Shah",
    "blogURL": "https://crunchify.com",
    "twitter": "https://twitter.com/Crunchify",
    "social": {
        "facebook": "http://facebook.com/Crunchify",
        "pinterest": "https://www.pinterest.com/Crunchify/crunchify-articles”,
        "rss": "https://crunchify.com/feed/"
    }
}

Escaped JSON: {\n    \"founder\": \"App Shah\",\n    \"blogURL\": \"https:\/\/crunchify.com\",\n    
\"twitter\": \"https:\/\/twitter.com\/Crunchify\",\n    \"social\": {\n        \"facebook\": 
\"http:\/\/facebook.com\/Crunchify\",\n        \"pinterest\": \"https:\/\/www.pinterest.com\/Crunchify\/crunchify-articles”,
\n        \"rss\": \"https:\/\/crunchify.com\/feed\/\"\n    }\n}\n

Process finished with exit code 0

---

Option-2: Using Apache Common’s commons-text dependency

• Add Maven’s pom.xml dependency

       <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-text</artifactId>
            <version>1.9</version>
        </dependency>

Complete code:

• Create class: CrunchifyEscapeJSONTutorial.java

package crunchify.com.java.tutorials;

import org.apache.commons.text.StringEscapeUtils;

/**
 * @author Crunchify.com
 * Program: In Java How to Escape JSON? Simple Tutorial using Apache Commons Library.
 */

public class CrunchifyEscapeJSONTutorial {

    public static void main(String[] args) {

        // StringEscapeUtils: Escapes and unescapes Strings for Java, Java Script, HTML and XML.
        // #ThreadSafe#
        // This code has been adapted from Apache Commons Lang 3.5.

        String crunchifyHTML = "{\n" +
                "    \"founder\": \"App Shah\",\n" +
                "    \"blogURL\": \"https://crunchify.com\",\n" +
                "    \"twitter\": \"https://twitter.com/Crunchify\",\n" +
                "    \"social\": {\n" +
                "        \"facebook\": \"http://facebook.com/Crunchify\",\n" +
                "        \"pinterest\": \"https://www.pinterest.com/Crunchify/crunchify-articles”,\n" +
                "        \"rss\": \"https://crunchify.com/feed/\"\n" +
                "    }\n" +
                "}";

        // escapeJson: Escapes the characters in a String using Json String rules.
        // Escapes any values it finds into their Json String form. Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.)

        // So a tab becomes the characters '\\' and 't'.
        // The only difference between Java strings and Json strings is that in Json, forward-slash (/) is escaped.
        String crunchifyResult = StringEscapeUtils.escapeJson(crunchifyHTML);

        crunchifyPrintUtils(crunchifyResult);

    }

    private static void crunchifyPrintUtils(String crunchifyResult) {
        System.out.println(crunchifyResult);
    }
}

IntelliJ IDEA Result:

We moved over to IntelliJ IDEA since last two years. Here is a console result.

{\n    \"founder\": \"App Shah\",\n    \"blogURL\": \"https:\/\/crunchify.com\",\n    \"twitter\": \"https:\/\/twitter.com\/Crunchify\",\n    \"social\": {\n        \"facebook\": \"http:\/\/facebook.com\/Crunchify\",\n        \"pinterest\": \"https:\/\/www.pinterest.com\/Crunchify\/crunchify-articles\u201D,\n        \"rss\": \"https:\/\/crunchify.com\/feed\/\"\n    }\n}

Process finished with exit code 0

Let me know if you face any issue running this Java Application.