We provide free performance testing tools for Java applications to help you find performance problems in your Java applications. The JProfiler profiler is used for measuring application performance, including the performance of Java code.
The performance testing tools in this free download will help you quickly identify performance problems in Java applications. The tools are easy to set up and use, and provide immediate feedback on hotspots in your application.
QEngine (ManageEngine)

QEngine (ManageEngine) is the most common and easy-to-use automated testing tool that helps in performance testing and load testing of your web applications.
Many developers find it to be the most simple and easy tool to use for finding out any leakage in their web services or websites. The key important feature of this testing tool is its ability to perform remote testing of web services from any geographical location.
Other than that, QEngine (ManageEngine) also offers various other testing options such as Functional testing, compatibility testing, stress testing, load testing, and Regression testing. This automated testing tool has the capacity to generate and simulate a lot of users so that the performance can be well analyzed during the maximum load. This is a free software available for users online.
System Requirement: This tool works with Microsoft Windows and Linux.
Loadstorm

Cloud load testing for web applications: Loadstorm is the cheapest available performance and load testing tool. Here, you have the option of creating your own test plans, testing criteria and testing scenario. You can generate up to 50000 concurrent users by generating traffic to your website and then carry out the testing.
Through this tool, you can bring an end to all the expensive performance testing tools. The cloud infrastructure which is used in this tool enables you to send a huge amount of requests per second.
There are thousands of servers available around the world for this software. They are proudly known as the lowest cloud load testing tool. There is no need for any scripting knowledge for using this tool.
You will be provided with many graphs and reports which measure the performance of various metrics such as error rates, average response time and the number of users. This tool is available for free, but the premium account comes with some more added features.
System Requirement: Windows OS.
CloudTest

SOASTA CloudTest is a performance testing tool for websites, mobile apps, APIs, and much more. Users and developers can use the cloud platform as their virtual testing lab. The developers can carry out their performance or load testing in the cloud platform in a cost-effective way.
CloudTest has the capacity to enable a number of users to use the website at the same time. It also increases the traffic of the website to know the actual performance under stress and heavy load.
The credit for developing this software goes to an American Technology company, SOASTA Inc. They provide many services for testing the websites and other web applications and now they also help in testing mobile applications.
They are not free services, the price differs according to the number of load injector machines required per hour by you. The trial version with the power of 100 concurrent users is available for free.
System Requirement: It runs on Windows, Linux and Mac OS.
Spiceworks

Spiceworks offers many free IT management tools, including inventory management, help desk workflow, and even cloud monitoring, in addition to the network monitoring solution I’m focusing on here. Built on agentless techniques like WMI (for Windows machines) and SNMP (for network and *nix systems), this free tool can provide insights into many network performance issues. You can also set up customizable notifications and restart services from within the app.
Note that Spiceworks is free because most of its revenue comes from the sale of ad displays in its network. It’s a small price to pay for a free solution, but it’s something to think about before you install.
Observium Community

Observium follows the “freemium” model that is now espoused by most of the open-source community—a core set of features for free, with additional options if you pay for them. While the “Community” (i.e., free) version supports an unlimited number of devices, Observium is still careful to say that it’s meant for home lab use. This is bolstered by the fact that the free version cannot scale past a single server. Run this on your corporate network at your own risk!
The free version also enjoys a 6-month patch and update cycle. If you want fixes any faster than twice a year, you’ll have to pay for them. One of the most painful features held back from the free version is the lack of alerting capabilities. Those caveats aside, you get a full auto-discovery of your devices and metrics (using SNMP and standard protocols, as usual).
Wireshark

Wireshark® is an open-source packet analyzer that uses libpcap (*nix) or winpcap (Windows) to capture packets and display them on its graphical front-end, while also providing good filtering, grouping, and analysis capabilities. It lets users capture traffic at wire speed or read from packet dumps and analyze details at microscopic levels. Wireshark supports almost every protocol, and has functionalities that filter based on packet type, source, destination, etc. It can analyze VoIP calls, plot IO graphs for all traffic from an interface, decrypt many protocols, export the output, and lots more.
Wireshark provides unlimited opportunities to study packets, which makes it a solid go-to for network, system, and security admins.
Auvik

Auvik’s cloud-based network management & monitoring solution is easy to use. It gives you a complete network picture through automated network discovery, inventory, and documentation. All these components are updated in real-time.
Auvik analyzes the network intelligently and provides insights on who is on the network and what are they doing through Auvik Traffic Insights. With this solution, you will be able to automate configuration backup and recovery. Auvik API will let you create powerful workflows.
Conclusion
Performance Testing Tools for Java Applications is devised to help test the performance of J2EE applications. It can measure both web applications and traditional business applications, allowing developers to quickly integrate testing functionality into their applications without sacrificing quality.