Fix sonar findings

README.md

@@ -52,7 +52,14 @@ The `ExitGuard` temporarily replaces the existing security manager.
 
 From version 1.2.0 on if a security guard existed before, it serves as a delegate for all security checks with the exception of the `checkExit`.
 
-**Warning:** The JREs Security Manager used by `ExitGuard` is deprecated and is not supported by Java 21 and later.
+**Warning:** The JREs Security Manager used by `ExitGuard` is deprecated and is not supported by Java 21 and later. It still works with Java 17 but logs the following warning:
+
+```
+WARNING: A terminally deprecated method in java.lang.System has been called
+WARNING: System::setSecurityManager has been called by ...
+WARNING: Please consider reporting this to the maintainers of ...
+WARNING: System::setSecurityManager will be removed in a future release
+```
 
 ## Asserting Data Sent to `System.out`
 

src/main/java/org/itsallcode/io/CapturingOutputStream.java

@@ -1,6 +1,7 @@
 package org.itsallcode.io;
 
 import java.io.*;
+import java.nio.charset.StandardCharsets;
 import java.util.Objects;
 
 /**
@@ -9,9 +10,9 @@
  */
 public class CapturingOutputStream extends OutputStream implements Capturable
 {
-    private OutputStream targetStream = null;
-    private ByteArrayOutputStream internalStream = null;
-    private String captureBuffer = null;
+    private OutputStream targetStream;
+    private ByteArrayOutputStream internalStream;
+    private String captureBuffer;
     private boolean forwardOutputToTarget = true;
 
     /**
@@ -69,7 +70,7 @@ public synchronized void close() throws IOException
     {
         if (this.internalStream != null)
         {
-            this.captureBuffer = this.internalStream.toString();
+            this.captureBuffer = this.internalStream.toString(StandardCharsets.UTF_8);
             this.internalStream.close();
         }
         this.internalStream = null;
@@ -101,7 +102,7 @@ public String getCapturedData()
         }
         else
         {
-            return this.internalStream.toString();
+            return this.internalStream.toString(StandardCharsets.UTF_8);
         }
     }
 

src/main/java/org/itsallcode/junit/sysextensions/AbstractSystemOutputGuard.java

@@ -4,6 +4,7 @@
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Executable;
 import java.lang.reflect.Parameter;
+import java.nio.charset.StandardCharsets;
 
 import org.itsallcode.io.Capturable;
 import org.itsallcode.io.CapturingOutputStream;
@@ -67,7 +68,8 @@ private void replaceSystemStreamWithCapturingStream(final ExtensionContext conte
     {
         final CapturingOutputStream capturingStream = new CapturingOutputStream(getSystemStream());
         context.getStore(getNamespace()).put(CAPTURING_OUTPUT_STREAM_KEY, capturingStream);
-        final PrintStream printStream = new PrintStream(getCapturingOutputStream(context));
+        final PrintStream printStream = new PrintStream(getCapturingOutputStream(context), false,
+                StandardCharsets.UTF_8);
         setSystemStream(printStream);
     }
 

src/test/java/org/itsallcode/junit/sysextensions/TestSytemOutWithBuffer.java → src/test/java/org/itsallcode/junit/sysextensions/TestSystemOutWithBuffer.java

@@ -6,18 +6,12 @@
 import java.io.PrintStream;
 
 import org.itsallcode.io.Capturable;
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 
 @ExtendWith(SystemOutGuard.class)
-class TestSytemOutWithBuffer
+class TestSystemOutWithBuffer
 {
-    @BeforeEach
-    void beforeEach()
-    {
-    }
-
     @SuppressWarnings("squid:S2699")
     @Test
     void testGetCapturedRegular(final Capturable stream) throws IOException
@@ -27,7 +21,7 @@ void testGetCapturedRegular(final Capturable stream) throws IOException
     }
 
     @Test
-    void testGetCapturedDataWithPrintStreamAroundSystemOut(final Capturable stream) throws IOException
+    void testGetCapturedDataWithPrintStreamAroundSystemOut(final Capturable stream)
     {
         final PrintStream printStream = new PrintStream(System.out);
         stream.capture();