DZone
Thanks for visiting DZone today,
Edit Profile
  • Manage Email Subscriptions
  • How to Post to DZone
  • Article Submission Guidelines
Sign Out View Profile
  • Post an Article
  • Manage My Drafts
Over 2 million developers have joined DZone.
Log In / Join
Please enter at least three characters to search
Refcards Trend Reports
Events Video Library
Refcards
Trend Reports

Events

View Events Video Library

Zones

Culture and Methodologies Agile Career Development Methodologies Team Management
Data Engineering AI/ML Big Data Data Databases IoT
Software Design and Architecture Cloud Architecture Containers Integration Microservices Performance Security
Coding Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks
Culture and Methodologies
Agile Career Development Methodologies Team Management
Data Engineering
AI/ML Big Data Data Databases IoT
Software Design and Architecture
Cloud Architecture Containers Integration Microservices Performance Security
Coding
Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance
Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks

Last call! Secure your stack and shape the future! Help dev teams across the globe navigate their software supply chain security challenges.

Modernize your data layer. Learn how to design cloud-native database architectures to meet the evolving demands of AI and GenAI workloads.

Releasing software shouldn't be stressful or risky. Learn how to leverage progressive delivery techniques to ensure safer deployments.

Avoid machine learning mistakes and boost model performance! Discover key ML patterns, anti-patterns, data strategies, and more.

Related

  • How to Convert Files to Thumbnail Images in Java
  • Understanding Floating-Point Precision Issues in Java
  • The Long Road to Java Virtual Threads
  • Exploring Exciting New Features in Java 17 With Examples

Trending

  • Immutable Secrets Management: A Zero-Trust Approach to Sensitive Data in Containers
  • AI, ML, and Data Science: Shaping the Future of Automation
  • A Modern Stack for Building Scalable Systems
  • Transforming AI-Driven Data Analytics with DeepSeek: A New Era of Intelligent Insights
  1. DZone
  2. Data Engineering
  3. Data
  4. A Complete Guide on How to Convert InputStream to String In Java

A Complete Guide on How to Convert InputStream to String In Java

Step-by-step instructions on How to Convert InputStream To String In Java. Understand Inputstream and convert it to String using BufferedReader.

By 
Eden Allen user avatar
Eden Allen
·
Mar. 02, 23 · Tutorial
Likes (3)
Comment
Save
Tweet
Share
7.2K Views

Join the DZone community and get the full member experience.

Join For Free

Java provides a wide range of I/O classes to help developers work with different data sources and destinations. One of the most common use cases is converting an InputStream to a String. This is particularly useful when working with data streams from a network connection or reading from a file. This article will explore different ways to convert an InputStream to a String in Java.

Understanding InputStream

Before we dive into converting InputStream to a String, let's take a moment to understand what InputStream is. In Java, an InputStream is an abstract class representing a stream of bytes. It is a superclass of all classes representing an input stream of bytes. An InputStream can be used to read data from various sources, such as a file, a network connection, or a byte array.

Some common methods available in InputStream are:

  • read() : Reads the next byte of data from the input stream.
  • read(byte[] b) : Reads up to b.length bytes of data from the input stream into an array of bytes.
  • skip(long n) : Skips over and discards n bytes of data from the input stream.

Converting InputStream to String

Now that we have a basic understanding of InputStream let's explore the different ways to convert an InputStream to a String.

Using BufferedReader

One of the simplest ways to convert an InputStream to a String is by using a BufferedReader. Here's an example code snippet:

 
public static String convertInputStreamToString(InputStream inputStream) throws IOException {
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
    StringBuilder stringBuilder = new StringBuilder();
    String line;
    while ((line = bufferedReader.readLine()) != null) {
        stringBuilder.append(line).append("\n");
    }
    bufferedReader.close();
    return stringBuilder.toString();
}


Here, we're creating a BufferedReader object by passing an InputStreamReader object that wraps the InputStream. We then read the contents of the BufferedReader line by line using. readLine() method, and append each line to a StringBuilder object. Finally, we close the BufferedReader and return the contents of the StringBuilder as a String.

Using Scanner

Another way to convert an InputStream to a String is by using a Scanner object. Here's an example code snippet:

 
public static String convertInputStreamToString(InputStream inputStream) {
    Scanner scanner = new Scanner(inputStream).useDelimiter("\\A");
    return scanner.hasNext() ? scanner.next() : "";
}


In this example, we're creating a Scanner object by passing the InputStream to its constructor. We then use the useDelimiter() method to set the delimiter to \\A, which is a regular expression that matches the beginning of the input. This tells the Scanner to read the entire input stream as a single token. Finally, we return the token as a String.

Using ByteArrayOutputStream

Another way to convert an InputStream to a String is by using a ByteArrayOutputStream. Here's an example code snippet:

 
public static String convertInputStreamToString(InputStream inputStream) throws IOException {
    ByteArrayOutputStream result = new ByteArrayOutputStream();
    byte[] buffer = new byte[1024];
    int length;
    while ((length = inputStream.read(buffer)) != -1) {
        result.write(buffer, 0, length);
    }
    return result.toString("UTF-8");
}


Here, we're creating a ByteArrayOutputStream object to which we're writing the contents of the InputStream. Next, we're reading the InputStream into a buffer of size 1024 bytes until we reach the end of the stream. Finally, we're returning the contents of the ByteArrayOutputStream as a String, specifying the character encoding as UTF-8.

Conclusion

In conclusion, converting an InputStream to a String is a common operation in Java when working with different data sources and destinations. In this article, we explored three different ways to achieve this; using BufferedReader, Scanner, and ByteArrayOutputStream. The choice of method depends on the specific use case, and developers should choose the method that works best for their needs. With these methods, developers can easily convert InputStreams to Strings and manipulate the data as needed in their Java applications.

Convert (command) Java (programming language) Strings Data Types

Opinions expressed by DZone contributors are their own.

Related

  • How to Convert Files to Thumbnail Images in Java
  • Understanding Floating-Point Precision Issues in Java
  • The Long Road to Java Virtual Threads
  • Exploring Exciting New Features in Java 17 With Examples

Partner Resources

×

Comments
Oops! Something Went Wrong

The likes didn't load as expected. Please refresh the page and try again.

ABOUT US

  • About DZone
  • Support and feedback
  • Community research
  • Sitemap

ADVERTISE

  • Advertise with DZone

CONTRIBUTE ON DZONE

  • Article Submission Guidelines
  • Become a Contributor
  • Core Program
  • Visit the Writers' Zone

LEGAL

  • Terms of Service
  • Privacy Policy

CONTACT US

  • 3343 Perimeter Hill Drive
  • Suite 100
  • Nashville, TN 37211
  • support@dzone.com

Let's be friends:

Likes
There are no likes...yet! 👀
Be the first to like this post!
It looks like you're not logged in.
Sign in to see who liked this post!