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jvm diagnose tool by swapping bytecode

// repository documentation

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# JVM ByteSwap Tool
![logo](https://raw.githubusercontent.com/sunwu51/swapper/master/sw-ico.png)

![actions](https://github.com/sunwu51/JVMByteSwapTool/actions/workflows/main.yml/badge.svg)

A tool that can hot swap the class byte code while jvm is running. Very suitable for `SpringBoot framework`.

Based on the jvm instrumentation tech, ASM, javassist and JVMTI.

# Usage
Download `swapper.jar` from the [release](https://github.com/sunwu51/JVMByteSwapTool/releases) page.

Make sure you have a JDK >= 1.8.
```bash
$ java -jar swapper.jar

// All of the java processes will be listed
// Choose the pid you want to attach
// Then the backend service will start
```

If you want to change the HTTP server port or WebSocket port:
```bash
$ java -jar -Dw_http_port=9999 -Dw_ws_port=19999 swapper.jar
```

## Web UI
After `swapper.jar` starts, visit `http://localhost:8000` and use the Web UI.

![image](https://i.imgur.com/WSKkrxX.png)

Now you can enjoy the functionalities of swapper tool.

For example, `Watch` some methods. Trigger this method, and then the params and return value and execution time cost will be printed.

![image](https://i.imgur.com/RaEZ1w5.png)

It's `Watch` one of the functions provided by swapper tool.

Get more functions and details from the [wiki](https://github.com/sunwu51/JVMByteSwapTool/wiki).

## TUI CLI
You can use the TUI client in the same way as the Web UI.

Install it from npm:
```bash
$ npm i -g jbs-client
$ jbs-client
```

Or download the standalone binary for your platform from the [swapper-tui releases](https://github.com/sunwu51/swapper-tui/releases), then run:
```bash
$ jbs-client
```

The interaction flow is consistent with the Web UI.

![img](https://i.imgur.com/5HTimiI.png)

swapper

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