Introduction:

Java developers often encounter the need to convert plain strings to HTML strings for rendering dynamic content in web applications. While this process may seem straightforward, there are several approaches to achieve it, each with its advantages and disadvantages. In this blog, we will explore multiple methods to convert Java strings to HTML strings, focusing on simplicity, efficiency, and code readability. 

Method 1: Using String Concatenation

The simplest approach to convert a Java string to an HTML string is by manually concatenating the HTML tags to the original string. We will use the + operator to combine the necessary tags with the content.

public class StringToHTMLConverter {
    public static String convertToHTMLStringUsingConcatenation(String content) {
        return "<p>" + content + "</p>";
    }

    public static void main(String[] args) {
        String input = "This is a simple Java String.";
        String htmlString = convertToHTMLStringUsingConcatenation(input);
        System.out.println(htmlString);
    }
}

Output:

<p>This is a simple Java String.</p>

Method 2: Using StringBuilder

While the string concatenation method is straightforward, it becomes inefficient when dealing with large strings or multiple concatenations. To overcome this, we can use StringBuilder, which provides better performance for string manipulations.

public class StringToHTMLConverter {
    public static String convertToHTMLStringUsingStringBuilder(String content) {
        StringBuilder htmlBuilder = new StringBuilder();
        htmlBuilder.append("<p>").append(content).append("</p>");
        return htmlBuilder.toString();
    }

    public static void main(String[] args) {
        String input = "This is a simple Java String.";
        String htmlString = convertToHTMLStringUsingStringBuilder(input);
        System.out.println(htmlString);
    }
}

Output:

<p>This is a simple Java String.</p>

Method 3: Using Java String.format()

Java's String.format() method allows us to construct formatted strings easily. We can leverage this method to create HTML strings by providing the content as a parameter.

public class StringToHTMLConverter {
    public static String convertToHTMLStringUsingFormat(String content) {
        return String.format("<p>%s</p>", content);
    }

    public static void main(String[] args) {
        String input = "This is a simple Java String.";
        String htmlString = convertToHTMLStringUsingFormat(input);
        System.out.println(htmlString);
    }
}

Output:

<p>This is a simple Java String.</p>

Method 4: Using Java StringEscapeUtils

Java provides the StringEscapeUtils class in the Apache Commons Text library, which simplifies the process of escaping special characters in HTML strings.

import org.apache.commons.text.StringEscapeUtils;

public class StringToHTMLConverter {
    public static String convertToHTMLStringUsingEscapeUtils(String content) {
        return "<p>" + StringEscapeUtils.escapeHtml4(content) + "</p>";
    }

    public static void main(String[] args) {
        String input = "<h1>Hello, World!</h1>";
        String htmlString = convertToHTMLStringUsingEscapeUtils(input);
        System.out.println(htmlString);
    }
}

Output:

<p>&lt;h1&gt;Hello, World!&lt;/h1&gt;</p>

Conclusion:

In this blog, we explored various methods to convert Java strings to HTML strings. We started with simple string concatenation and demonstrated how to use StringBuilder for improved performance. We then learned how to use String.format() to create formatted HTML strings. Finally, we utilized the StringEscapeUtils from the Apache Commons Text library to safely escape special characters in the HTML content.