Handle closed terminal gracefully on shell exit

spring-shell-jline/src/main/java/org/springframework/shell/jline/JLineInputProvider.java

@@ -23,9 +23,18 @@ public JLineInputProvider(LineReader lineReader) {
 
 	@Override
 	public String readInput() {
-		AttributedString prompt = this.promptProvider.getPrompt();
-		String ansiPrompt = prompt.toAnsi(this.lineReader.getTerminal());
-		return this.lineReader.readLine(ansiPrompt);
+		try {
+			AttributedString prompt = this.promptProvider.getPrompt();
+			String ansiPrompt = prompt.toAnsi(this.lineReader.getTerminal());
+			return this.lineReader.readLine(ansiPrompt);
+		}
+		catch (IllegalStateException ex) {
+			// Terminal closed externally (e.g. process killed from an IDE): treat as EOF.
+			if (ex.getMessage() != null && ex.getMessage().contains("closed")) {
+				return null;
+			}
+			throw ex;
+		}
 	}
 
 	public void setPromptProvider(PromptProvider promptProvider) {

spring-shell-jline/src/main/java/org/springframework/shell/jline/JLineShellRunner.java

@@ -55,12 +55,23 @@ public JLineShellRunner(JLineInputProvider inputProvider, CommandParser commandP
 
 	@Override
 	public void print(String message) {
-		this.lineReader.getTerminal().writer().println(message);
+		ignoringClosedTerminal(() -> this.lineReader.getTerminal().writer().println(message));
 	}
 
 	@Override
 	public void flush() {
-		lineReader.getTerminal().flush();
+		ignoringClosedTerminal(() -> this.lineReader.getTerminal().flush());
+	}
+
+	private void ignoringClosedTerminal(Runnable action) {
+		try {
+			action.run();
+		}
+		catch (IllegalStateException ex) {
+			if (ex.getMessage() == null || !ex.getMessage().contains("closed")) {
+				throw ex;
+			}
+		}
 	}
 
 	@Override

spring-shell-jline/src/test/java/org/springframework/shell/jline/JLineShellRunnerTests.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright 2025-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.shell.jline;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PipedInputStream;
+import java.io.PipedOutputStream;
+import java.nio.charset.StandardCharsets;
+
+import org.jline.reader.LineReader;
+import org.jline.reader.LineReaderBuilder;
+import org.jline.terminal.Terminal;
+import org.jline.terminal.impl.DumbTerminal;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.shell.core.command.CommandRegistry;
+import org.springframework.shell.core.command.DefaultCommandParser;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+class JLineShellRunnerTests {
+
+	private PipedInputStream pipedInputStream;
+
+	private PipedOutputStream pipedOutputStream;
+
+	private Terminal terminal;
+
+	private JLineInputProvider inputProvider;
+
+	private JLineShellRunner runner;
+
+	@BeforeEach
+	void setup() throws Exception {
+		this.pipedInputStream = new PipedInputStream();
+		this.pipedOutputStream = new PipedOutputStream();
+		this.pipedInputStream.connect(this.pipedOutputStream);
+		ByteArrayOutputStream consoleOut = new ByteArrayOutputStream();
+		this.terminal = new DumbTerminal("terminal", "ansi", this.pipedInputStream, consoleOut, StandardCharsets.UTF_8);
+		LineReader lineReader = LineReaderBuilder.builder().terminal(this.terminal).build();
+		this.inputProvider = new JLineInputProvider(lineReader);
+		CommandRegistry commandRegistry = new CommandRegistry();
+		this.runner = new JLineShellRunner(this.inputProvider, new DefaultCommandParser(commandRegistry),
+				commandRegistry);
+	}
+
+	@AfterEach
+	void cleanup() throws Exception {
+		this.pipedOutputStream.close();
+		this.pipedInputStream.close();
+	}
+
+	@Test
+	void runShouldExitGracefullyWhenTerminalIsClosed() throws Exception {
+		this.terminal.close();
+		assertDoesNotThrow(() -> this.runner.run(new String[0]));
+	}
+
+	@Test
+	void readInputShouldReturnNullWhenTerminalIsClosed() throws Exception {
+		this.terminal.close();
+		assertNull(this.inputProvider.readInput());
+	}
+
+	@Test
+	void printShouldNotThrowWhenTerminalIsClosed() throws Exception {
+		this.terminal.close();
+		assertDoesNotThrow(() -> this.runner.print("anything"));
+	}
+
+	@Test
+	void flushShouldNotThrowWhenTerminalIsClosed() throws Exception {
+		this.terminal.close();
+		assertDoesNotThrow(() -> this.runner.flush());
+	}
+
+}