Easiest Way to Convert Stack Trace to String

The easiest way to convert the result of Throwable.getStackTrace() to a string is by using Apache Commons Lang’s ExceptionUtils.getStackTrace() method, which provides a one-line solution without manual string manipulation. For projects without external dependencies, you can use a StringWriter with PrintWriter to capture the stack trace output, though this requires more code. Both approaches convert the stack trace to a readable string format suitable for logging or display purposes.

Contents

• Apache Commons Lang Method - Easiest Approach
• Core Java StringWriter Approach
• Manual StringBuilder Approach
• Google Guava Alternative
• Comparison of Methods
• Practical Examples

Apache Commons Lang Method - Easiest Approach

The simplest and most straightforward method to convert a stack trace to a string is using Apache Commons Lang’s ExceptionUtils.getStackTrace(). This utility method handles all the complexity internally and returns a properly formatted stack trace string.

import org.apache.commons.lang3.exception.ExceptionUtils;

// When catching an exception
try {
    // Your code that might throw an exception
} catch (Exception e) {
    String stackTraceAsString = ExceptionUtils.getStackTrace(e);
    // Use the stack trace string
    System.out.println(stackTraceAsString);
}

Key advantages:

• Single line of code
• Properly formatted output
• Handles nested exceptions
• Widely used and well-tested
• Available in most Java projects

To use this method, you need to include the Apache Commons Lang dependency in your project:

Maven:

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>

Gradle:

implementation 'org.apache.commons:commons-lang3:3.12.0'

As Baeldung explains, “Getting the stack trace of an exception as a String isn’t difficult, but it’s far from being intuitive. This article presents two ways of doing it, either using core Java or using Apache Commons-Lang.”

Core Java StringWriter Approach

If you prefer not to use external libraries, Java provides a built-in approach using StringWriter and PrintWriter. This method captures the standard output of printStackTrace() into a string.

import java.io.StringWriter;
import java.io.PrintWriter;

try {
    // Your code that might throw an exception
} catch (Exception e) {
    StringWriter sw = new StringWriter();
    PrintWriter pw = new PrintWriter(sw);
    e.printStackTrace(pw);
    String stackTraceAsString = sw.toString();
    
    // Use the stack trace string
    System.out.println(stackTraceAsString);
}

Using try-with-resources (Java 7+):

try (StringWriter sw = new StringWriter();
     PrintWriter pw = new PrintWriter(sw)) {
    e.printStackTrace(pw);
    String stackTraceAsString = sw.toString();
    // Use the stack trace string
}

According to Stack Overflow, this approach “prints the exception backtrace to the specified print Writer such as a PrintWriter.”

Advantages:

• No external dependencies required
• Standard Java API
• Reliable and well-tested

Disadvantages:

• More verbose than Apache Commons solution
• Requires resource management

Manual StringBuilder Approach

You can also manually convert the StackTraceElement[] array returned by getStackTrace() to a string using StringBuilder. This gives you more control over the formatting.

try {
    // Your code that might throw an exception
} catch (Exception e) {
    StringBuilder sb = new StringBuilder();
    sb.append(e.toString()).append("\n");
    
    for (StackTraceElement element : e.getStackTrace()) {
        sb.append("\tat ").append(element.toString()).append("\n");
    }
    
    String stackTraceAsString = sb.toString();
    // Use the stack trace string
}

As Java Practices demonstrates, you can create a custom method like:

public static String getCustomStackTrace(Throwable throwable) {
    StringBuilder result = new StringBuilder(throwable.toString());
    String NL = System.getProperty("line.separator");
    result.append(NL);
    
    for (StackTraceElement element : throwable.getStackTrace()) {
        result.append(element);
        result.append(NL);
    }
    return result.toString();
}

Advantages:

• Full control over formatting
• No external dependencies
• Easy to customize output format

Disadvantages:

• Most verbose approach
• Requires manual formatting
• Prone to formatting errors

Google Guava Alternative

Another excellent library-based solution is Google Guava’s Throwables.getStackTraceAsString() method, which provides similar functionality to Apache Commons Lang.

import com.google.common.base.Throwables;

try {
    // Your code that might throw an exception
} catch (Exception e) {
    String stackTraceAsString = Throwables.getStackTraceAsString(e);
    // Use the stack trace string
}

Maven dependency:

<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>32.1.2-jre</version>
</dependency>

As Java Development Journal mentions, “Google Guava class provide Throwable utility class to convert stack trace to String.”

Comparison of Methods

Best choice recommendations:

• For simplicity: Apache Commons Lang
• For minimal dependencies: StringWriter approach
• For maximum control: Manual StringBuilder
• For Guava users: Google Guava’s Throwables class

Practical Examples

Example 1: Basic Exception Handling

public class StackTraceConverter {
    public static void main(String[] args) {
        try {
            int result = 10 / 0; // This will cause ArithmeticException
        } catch (Exception e) {
            // Using Apache Commons Lang (easiest)
            String commonsTrace = ExceptionUtils.getStackTrace(e);
            System.out.println("Apache Commons:\n" + commonsTrace);
            
            // Using core Java
            StringWriter sw = new StringWriter();
            e.printStackTrace(new PrintWriter(sw));
            String javaTrace = sw.toString();
            System.out.println("Core Java:\n" + javaTrace);
        }
    }
}

Example 2: Logging Integration

import org.apache.commons.lang3.exception.ExceptionUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class LoggingExample {
    private static final Logger logger = LoggerFactory.getLogger(LoggingExample.class);
    
    public void processData(String input) {
        try {
            // Process data
            int result = Integer.parseInt(input) / 0;
        } catch (Exception e) {
            // Log full stack trace
            logger.error("Error processing input: {}\n{}", input, ExceptionUtils.getStackTrace(e));
            
            // Or log just the exception message
            // logger.error("Error processing input: " + input, e);
        }
    }
}

Example 3: Custom Error Reporting

import org.apache.commons.lang3.exception.ExceptionUtils;

public class ErrorReporter {
    public String generateErrorReport(Exception e) {
        return "Error Report\n" +
               "============\n" +
               "Exception: " + e.getClass().getSimpleName() + "\n" +
               "Message: " + e.getMessage() + "\n" +
               "Stack Trace:\n" + 
               ExceptionUtils.getStackTrace(e);
    }
}

As LambdaTest Community notes, developers often need to “transform [the stack trace] into a single string that clearly shows the full trace” for logging or display purposes.

Sources

1. Stack Overflow - How can I convert a stack trace to a string?
2. Baeldung - Converting a Stack Trace to a String in Java
3. Java Practices - Stack trace as String
4. Vultr Docs - Java Program to Convert a Stack Trace to a String
5. Java Development Journal - Convert Stack Trace to String in Java
6. GeeksforGeeks - Throwable getStackTrace() method in Java
7. LambdaTest Community - What is the easiest way to convert a Java stack trace to string

Conclusion

Converting a Throwable.getStackTrace() result to a string is straightforward with the right approach. The easiest method is using Apache Commons Lang’s ExceptionUtils.getStackTrace(), which provides a clean, one-line solution that handles all formatting automatically. For projects without external dependencies, the StringWriter and PrintWriter approach offers a reliable core Java alternative that captures the standard stack trace output.

Key recommendations:

• Use Apache Commons Lang for maximum simplicity and reliability
• Consider Google Guava’s Throwables.getStackTraceAsString() if already using Guava
• Use core Java approaches when external dependencies are not an option
• Choose the manual StringBuilder approach only when you need custom formatting

All methods provide readable stack trace strings suitable for logging, error reporting, or display purposes. The choice ultimately depends on your project’s dependencies and coding preferences.