Add support to read (secure) input from commands

Author: fmbenhassine

spring-shell-core/src/main/java/org/springframework/shell/core/ConsoleInputReader.java

@@ -0,0 +1,58 @@
+/*
+ * 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.core;
+
+import java.io.Console;
+
+/**
+ * Implementation of {@link InputReader} that reads input from the system console.
+ *
+ * @author Mahmoud Ben Hassine
+ * @since 4.0.0
+ */
+public class ConsoleInputReader implements InputReader {
+
+	private final Console console;
+
+	/**
+	 * Create a new {@link ConsoleInputReader} instance.
+	 * @param console the system console
+	 */
+	public ConsoleInputReader(Console console) {
+		this.console = console;
+	}
+
+	@Override
+	public String readInput() {
+		return this.console.readLine();
+	}
+
+	@Override
+	public String readInput(String prompt) {
+		return this.console.readLine(prompt);
+	}
+
+	@Override
+	public char[] readPassword() {
+		return this.console.readPassword();
+	}
+
+	@Override
+	public char[] readPassword(String prompt) {
+		return this.console.readPassword(prompt);
+	}
+
+}

spring-shell-core/src/main/java/org/springframework/shell/core/InputReader.java

@@ -0,0 +1,64 @@
+/*
+ * 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.core;
+
+/**
+ * Interface for reading input from the user.
+ *
+ * @author Mahmoud Ben Hassine
+ * @since 4.0.0
+ */
+public interface InputReader {
+
+	/**
+	 * Read a line of input from the user.
+	 * @return the input line
+	 * @throws Exception if an error occurs while reading input
+	 */
+	default String readInput() throws Exception {
+		return readInput("");
+	}
+
+	/**
+	 * Read a line of input from the user with a prompt.
+	 * @param prompt the prompt to display to the user
+	 * @return the input line
+	 * @throws Exception if an error occurs while reading input
+	 */
+	default String readInput(String prompt) throws Exception {
+		throw new UnsupportedOperationException("readInput with prompt not implemented");
+	}
+
+	/**
+	 * Read a password from the user.
+	 * @return the password as a character array
+	 * @throws Exception if an error occurs while reading the password
+	 */
+	default char[] readPassword() throws Exception {
+		return readPassword("");
+	}
+
+	/**
+	 * Read a password from the user with a prompt.
+	 * @param prompt the prompt to display to the user
+	 * @return the password as a character array
+	 * @throws Exception if an error occurs while reading the password
+	 */
+	default char[] readPassword(String prompt) throws Exception {
+		throw new UnsupportedOperationException("readPassword with prompt not implemented");
+	}
+
+}

spring-shell-core/src/main/java/org/springframework/shell/core/InteractiveShellRunner.java

@@ -94,7 +94,8 @@ public void run(String[] args) throws Exception {
 			}
 			ParsedInput parsedInput = this.commandParser.parse(input);
 			try {
-				CommandContext commandContext = new CommandContext(parsedInput, this.commandRegistry, getWriter());
+				CommandContext commandContext = new CommandContext(parsedInput, this.commandRegistry, getWriter(),
+						getReader());
 				ExitStatus exitStatus = this.commandExecutor.execute(commandContext);
 				if (ExitStatus.OK.code() != exitStatus.code()) { // business error
 					print("Error while executing command " + parsedInput.commandName() + ": "
@@ -136,4 +137,10 @@ public void run(String[] args) throws Exception {
 	 */
 	public abstract PrintWriter getWriter();
 
+	/**
+	 * Get the input reader.
+	 * @return the input reader
+	 */
+	public abstract InputReader getReader();
+
 }

spring-shell-core/src/main/java/org/springframework/shell/core/NonInteractiveShellRunner.java

@@ -51,6 +51,10 @@ public class NonInteractiveShellRunner implements ShellRunner {
 	// Use a no-op PrintWriter since output is not needed in non-interactive mode
 	private final PrintWriter outputWriter = new PrintWriter(PrintWriter.nullWriter());
 
+	// Use a no-op InputReader since input is not needed in non-interactive mode
+	private final InputReader inputReader = new InputReader() {
+	};
+
 	/**
 	 * Create a new {@link NonInteractiveShellRunner} instance.
 	 * @param commandParser the command parser
@@ -105,7 +109,8 @@ private void executeScript(File script) {
 				break;
 			}
 			ParsedInput parsedInput = this.commandParser.parse(input);
-			CommandContext commandContext = new CommandContext(parsedInput, this.commandRegistry, this.outputWriter);
+			CommandContext commandContext = new CommandContext(parsedInput, this.commandRegistry, this.outputWriter,
+					this.inputReader);
 			ExitStatus exitStatus = this.commandExecutor.execute(commandContext);
 			if (ExitStatus.OK.code() != exitStatus.code()) { // business error
 				log.error("Command " + parsedInput.commandName() + " returned an error: " + exitStatus.description()
@@ -117,7 +122,8 @@ private void executeScript(File script) {
 
 	private void executeCommand(String primaryCommand) {
 		ParsedInput parsedInput = this.commandParser.parse(primaryCommand);
-		CommandContext commandContext = new CommandContext(parsedInput, this.commandRegistry, this.outputWriter);
+		CommandContext commandContext = new CommandContext(parsedInput, this.commandRegistry, this.outputWriter,
+				this.inputReader);
 		ExitStatus exitStatus = this.commandExecutor.execute(commandContext);
 		if (ExitStatus.OK.code() != exitStatus.code()) {
 			log.error("Command " + parsedInput.commandName() + " returned an error: " + exitStatus.description());

spring-shell-core/src/main/java/org/springframework/shell/core/SystemShellRunner.java

@@ -60,4 +60,9 @@ public PrintWriter getWriter() {
 		return this.console.writer();
 	}
 
+	@Override
+	public InputReader getReader() {
+		return new ConsoleInputReader(this.console);
+	}
+
 }

spring-shell-core/src/main/java/org/springframework/shell/core/command/CommandContext.java

@@ -19,13 +19,16 @@
 
 import org.jspecify.annotations.Nullable;
 
+import org.springframework.shell.core.InputReader;
+
 /**
  * Interface containing runtime information about the current command invocation.
  *
  * @author Mahmoud Ben Hassine
  * @since 4.0.0
  */
-public record CommandContext(ParsedInput parsedInput, CommandRegistry commandRegistry, PrintWriter outputWriter) {
+public record CommandContext(ParsedInput parsedInput, CommandRegistry commandRegistry, PrintWriter outputWriter,
+		InputReader inputReader) {
 
 	/**
 	 * Retrieve a command option by its name (long or short).

spring-shell-core/src/test/java/org/springframework/shell/core/command/CommandAvailabilityTests.java

@@ -20,6 +20,7 @@
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.shell.core.InputReader;
 import org.springframework.shell.core.command.availability.Availability;
 import org.springframework.shell.core.command.availability.AvailabilityProvider;
 
@@ -50,7 +51,7 @@ public ExitStatus doExecute(CommandContext commandContext) {
 		};
 		StringWriter stringWriter = new StringWriter();
 		CommandContext commandContext = new CommandContext(mock(ParsedInput.class), mock(CommandRegistry.class),
-				new PrintWriter(stringWriter));
+				new PrintWriter(stringWriter), mock(InputReader.class));
 
 		// when
 		ExitStatus exitStatus = command.execute(commandContext);

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

@@ -1,7 +1,6 @@
 package org.springframework.shell.jline;
 
 import org.jline.reader.LineReader;
-import org.jline.terminal.Terminal;
 import org.jline.utils.AttributedString;
 import org.jline.utils.AttributedStyle;
 
@@ -33,8 +32,8 @@ public void setPromptProvider(PromptProvider promptProvider) {
 		this.promptProvider = promptProvider;
 	}
 
-	public Terminal getTerminal() {
-		return this.lineReader.getTerminal();
+	public LineReader getLineReader() {
+		return this.lineReader;
 	}
 
 }

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

@@ -0,0 +1,61 @@
+/*
+ * 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 org.jline.reader.LineReader;
+
+import org.springframework.shell.core.InputReader;
+
+/**
+ * Implementation of {@link InputReader} that reads input using JLine's
+ * {@link LineReader}.
+ *
+ * @author Mahmoud Ben Hassine
+ * @since 4.0.0
+ */
+public class JLineInputReader implements InputReader {
+
+	private final LineReader lineReader;
+
+	/**
+	 * Create a new {@link JLineInputReader} instance.
+	 * @param lineReader the JLine line reader
+	 */
+	public JLineInputReader(LineReader lineReader) {
+		this.lineReader = lineReader;
+	}
+
+	@Override
+	public String readInput() {
+		return lineReader.readLine();
+	}
+
+	@Override
+	public String readInput(String prompt) {
+		return lineReader.readLine(prompt);
+	}
+
+	@Override
+	public char[] readPassword() {
+		return lineReader.readLine('*').toCharArray();
+	}
+
+	@Override
+	public char[] readPassword(String prompt) {
+		return lineReader.readLine(prompt, '*').toCharArray();
+	}
+
+}

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

@@ -18,8 +18,9 @@
 import java.io.Console;
 import java.io.PrintWriter;
 
-import org.jline.terminal.Terminal;
+import org.jline.reader.LineReader;
 
+import org.springframework.shell.core.InputReader;
 import org.springframework.shell.core.InteractiveShellRunner;
 import org.springframework.shell.core.command.CommandParser;
 import org.springframework.shell.core.command.CommandRegistry;
@@ -32,7 +33,7 @@
  */
 public class JLineShellRunner extends InteractiveShellRunner {
 
-	private final Terminal terminal;
+	private final LineReader lineReader;
 
 	/**
 	 * Create a new {@link JLineShellRunner} instance.
@@ -43,22 +44,27 @@ public class JLineShellRunner extends InteractiveShellRunner {
 	public JLineShellRunner(JLineInputProvider inputProvider, CommandParser commandParser,
 			CommandRegistry commandRegistry) {
 		super(inputProvider, commandParser, commandRegistry);
-		this.terminal = inputProvider.getTerminal();
+		this.lineReader = inputProvider.getLineReader();
 	}
 
 	@Override
 	public void print(String message) {
-		this.terminal.writer().println(message);
+		this.lineReader.getTerminal().writer().println(message);
 	}
 
 	@Override
 	public void flush() {
-		this.terminal.flush();
+		lineReader.getTerminal().flush();
 	}
 
 	@Override
 	public PrintWriter getWriter() {
-		return this.terminal.writer();
+		return this.lineReader.getTerminal().writer();
+	}
+
+	@Override
+	public InputReader getReader() {
+		return new JLineInputReader(this.lineReader);
 	}
 
 }