🔄 Recap: What We Did in Part 1?
In Part 1, we successfully set up MITM Proxy to intercept network requests from a mobile app running on an Android/iOS device. We learned how to:
✅ Install MITM Proxy and start a proxy server.
✅ Configure proxy settings on a real device/emulator.
✅ Intercept HTTP & HTTPS requests using a MITM CA Certificate.
🚀 That was fun, but now let’s take it to the next level!
🔥 What’s Next?
We don’t just want to view network logs—we want to capture them programmatically in our automation framework.
And for that, we’ll use MITM Proxy’s Java Client!
🤖 What is the MITM Proxy Java Client?
The MITM Proxy Java Client (mitmproxy-java) acts as a bridge between MITM Proxy and your Java-based automation framework.
💡 Here’s how it works:
✅ MITM Proxy starts a WebSocket server.
✅ A Python plugin inside MITM Proxy sends network traffic to the Java client.
✅ The Java client captures and stores network requests for analysis.
With this setup, we can:
🔍 Capture API calls made by the mobile app.
📄 Save network logs for debugging.
🔗 Attach logs to test reports.
⚙️ Step 1: Install the Required Dependencies
📌 Prerequisites
Before setting up the Java client, make sure you have:
1️⃣ MITM Proxy v9+ installed and working.
2️⃣ Python 3.6+ (MITM Proxy uses async WebSockets).
3️⃣ WebSockets module installed:
pip3 install websockets
📌 Add MITM Proxy Java Dependency to Your Project
If you’re using Maven, add this dependency to your pom.xml:
<dependency>
<groupId>io.appium</groupId>
<artifactId>mitmproxy-java</artifactId>
<version>2.0.2</version>
</dependency>
🚨 Note: The latest version is not yet available in the official repository, so you may need to clone the source code and build your own JAR.
📂 Step 2: Integrate MITM Proxy Java Client in Your Framework
🕒 Step 2.1: Create a Class to Store Intercepted Messages
To store network logs with timestamps, create InterceptedMessages.java:
import io.appium.mitmproxy.InterceptedMessage;
import lombok.Getter;
import lombok.Setter;
import lombok.experimental.Accessors;
import java.util.Date;
public class InterceptedMessages {
@Accessors(chain = true)
@Getter@Setter
private Date timestamp;
@Accessors(chain = true)
@Getter@Setter
private InterceptedMessage interceptedMessage;
}
🚀 Now every intercepted request will be saved with a timestamp!
🛠 Step 2.2: Add a Handler to Start & Stop MITM Proxy
Now, let’s create MITMProxy.java to:
✅ Start the proxy listener.
✅ Capture network traffic.
✅ Stop the proxy when needed.
import io.appium.mitmproxy.InterceptedMessage;
import io.appium.mitmproxy.MitmproxyJava;
import lombok.Getter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import java.util.concurrent.TimeoutException;
public class MITMProxy {
@Getter
private final List<InterceptedMessages> networkCalls = new ArrayList<>();
private static MITMProxy proxyInstance = null;
private MitmproxyJava proxy;
private MITMProxy() {
startProxyListener();
}
public static MITMProxy getProxy() {
if (proxyInstance == null)
proxyInstance = new MITMProxy();
return proxyInstance;
}
private void startProxyListener() {
System.out.println("🚀 Starting MITM Proxy Listener...");
List<String> extraMitmproxyParams = Arrays.asList("--showhost", "<domain-name-filter>");
int mitmproxyPort = 8090;
this.proxy = new MitmproxyJava(getMitmDumpPath(), (InterceptedMessage message) -> {
InterceptedMessages interceptedMessage = new InterceptedMessages()
.setTimestamp(new Date())
.setInterceptedMessage(message);
networkCalls.add(interceptedMessage);
System.out.println("🔍 Captured Network Request at: " + interceptedMessage.getTimestamp());
System.out.println("📡 Request Details: " + message);
return message;
}, mitmproxyPort, extraMitmproxyParams);
try {
String processId = ProcessExecutor.executeCommandSync("lsof -t -i:" + mitmproxyPort + " -sTCP:LISTEN").trim();
if (!processId.isEmpty())
ProcessExecutor.executeCommandSync("kill -9 " + processId);
this.proxy.start();
} catch (IOException | TimeoutException e) {
throw new RuntimeException("❌ Failed to Start Proxy: " + e.getMessage());
}
System.out.println("✅ Proxy Listener Started Successfully!");
}
private String getMitmDumpPath() {
String result = ProcessExecutor.executeCommandSync("whereis mitmdump");
return result.split("mitmdump: ")[1].split(" ")[0].trim();
}
public void stopProxyListener() {
System.out.println("🛑 Stopping MITM Proxy Listener...");
try {
this.proxy.stop();
} catch (InterruptedException e) {
throw new RuntimeException("❌ Failed to Stop Proxy: " + e.getMessage());
}
System.out.println("✅ Proxy Listener Stopped Successfully!");
}
public void printCapturedLogs() {
System.out.println("📜 Printing Captured Network Logs...");
if (networkCalls.isEmpty()) {
System.out.println("⚠️ No network requests were intercepted.");
return;
}
for (InterceptedMessages msg : networkCalls) {
System.out.println("⏳ Captured Request at: " + msg.getTimestamp());
System.out.println("📡 Request Details: " + msg.getInterceptedMessage());
System.out.println("--------------------------------------------------");
}
}
}
🔥 What Does This Class Do?
✅ Automatically starts MITM Proxy when called.
✅ Captures every intercepted request and stores it with a timestamp.
✅ Prevents port conflicts by killing any existing process on the same port.
🚀 Step 3: Start Capturing Network Logs
🎬 Start the Proxy
MITMProxy.getProxy();
👉 This starts the MITM Proxy and begins capturing network requests.
📄 Fetch Intercepted Logs
networkLogMessage = MITMProxy.getProxy().getNetworkCalls();
👉 This retrieves all captured network logs, which can be saved or attached to reports.
🛑 Stop the Proxy
MITMProxy.getProxy().stopProxyListener();
👉 This stops the proxy when tests are complete.
🔍 Verifying Captured Logs
Once your tests have run, print the captured logs to verify that requests are being intercepted:
for (InterceptedMessages msg : MITMProxy.getProxy().getNetworkCalls()) {
System.out.println("Captured Request at: " + msg.getTimestamp());
System.out.println("Request Details: " + msg.getInterceptedMessage());
}
🎉 Now you can capture and analyze every network request in your tests!
🎯 What’s Next?
✅ We can now intercept API calls from our mobile automation framework! 🎯
But what if we need to store these logs for later analysis? 🤔
👉 In Part 3, we’ll:
✅ Save network logs to files for debugging.
✅ Attach logs to automation test reports.
✅ Filter out unwanted noise from logs.
Stay tuned for Part 3! 🚀🔥
💬 Questions? Drop a comment below!
