Adds ResultHandler, a way to dynamically deal with method execution results

src/main/java/org/springframework/shell2/Bootstrap.java

@@ -16,6 +16,11 @@
 
 package org.springframework.shell2;
 
+import java.io.IOException;
+
+import org.jline.terminal.Terminal;
+import org.jline.terminal.TerminalBuilder;
+
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.ConfigurableApplicationContext;
@@ -51,4 +56,9 @@ public class Bootstrap {
 		return new DefaultParameterResolver(conversionService);
 	}
 
+	@Bean
+	public Terminal terminal() throws IOException {
+		return TerminalBuilder.builder().build();
+	}
+
 }

src/main/java/org/springframework/shell2/JLineShell.java

@@ -40,8 +40,6 @@ import org.jline.reader.LineReaderBuilder;
 import org.jline.reader.ParsedLine;
 import org.jline.reader.impl.DefaultParser;
 import org.jline.terminal.Terminal;
-import org.jline.terminal.TerminalBuilder;
-import org.jline.utils.AttributedCharSequence;
 import org.jline.utils.AttributedString;
 import org.jline.utils.AttributedStringBuilder;
 import org.jline.utils.AttributedStyle;
@@ -50,7 +48,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ApplicationContext;
 import org.springframework.core.DefaultParameterNameDiscoverer;
 import org.springframework.core.MethodParameter;
-import org.springframework.core.convert.ConversionService;
+import org.springframework.shell2.result.ResultHandlers;
 import org.springframework.stereotype.Component;
 import org.springframework.util.ReflectionUtils;
 
@@ -61,17 +59,18 @@ import org.springframework.util.ReflectionUtils;
 public class JLineShell implements Shell {
 
 	@Autowired
-	private ApplicationContext applicationContext;
+	private ResultHandlers resultHandlers;
 
 	@Autowired
-	private ConversionService conversionService;
-
-	private Map<String, Object> commandBeans;
+	private ApplicationContext applicationContext;
 
 	private Map<String, MethodTarget> methodTargets = new HashMap<>();
 
 	private LineReader lineReader;
 
+	@Autowired
+	private Terminal terminal;
+
 	@Autowired
 	private List<ParameterResolver> parameterResolvers = new ArrayList<>();
 
@@ -86,7 +85,6 @@ public class JLineShell implements Shell {
 			methodTargets.putAll(resolver.resolve(applicationContext));
 		}
 
-		Terminal terminal = TerminalBuilder.builder().build();
 		LineReaderBuilder lineReaderBuilder = LineReaderBuilder.builder()
 				.terminal(terminal)
 				.appName("Foo")
@@ -189,12 +187,7 @@ public class JLineShell implements Shell {
 					result = e;
 				}
 
-				if (result instanceof AttributedCharSequence) {
-					System.out.println(((AttributedCharSequence) result).toAnsi(lineReader.getTerminal()));
-				}
-				else {
-					System.out.println(String.valueOf(result));
-				}
+				resultHandlers.handleResult(result);
 
 			}
 			else {
@@ -202,4 +195,5 @@ public class JLineShell implements Shell {
 			}
 		}
 	}
+
 }

src/main/java/org/springframework/shell2/result/AttributedCharSequenceResultHandler.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2015 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
+ *
+ *      http://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.shell2.result;
+
+import org.jline.terminal.Terminal;
+import org.jline.utils.AttributedCharSequence;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+/**
+ * A {@link ResultHandler} that knows how to render JLine's {@link AttributedCharSequence}.
+ *
+ * @author Eric Bottard
+ */
+@Component
+public class AttributedCharSequenceResultHandler implements ResultHandler<AttributedCharSequence> {
+
+	private final Terminal terminal;
+
+	@Autowired
+	public AttributedCharSequenceResultHandler(Terminal terminal) {
+		this.terminal = terminal;
+	}
+
+	@Override
+	public void handleResult(AttributedCharSequence result) {
+		System.out.println(result.toAnsi(terminal));
+	}
+}

src/main/java/org/springframework/shell2/result/DefaultResultHandler.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2015 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
+ *
+ *      http://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.shell2.result;
+
+import org.springframework.stereotype.Component;
+
+/**
+ * A simple {@link ResultHandler} that deals with Objects (hence comes as a last resort)
+ * and prints the {@link Object#toString()} value of results to standard out.
+ *
+ * @author Eric Bottard
+ */
+@Component
+public class DefaultResultHandler implements ResultHandler<Object> {
+
+	@Override
+	public void handleResult(Object result) {
+		System.out.println(String.valueOf(result));
+	}
+}

src/main/java/org/springframework/shell2/result/IterableResultHandler.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2015 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
+ *
+ *      http://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.shell2.result;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+/**
+ * A {@link ResultHandler} that deals with {@link Iterable}s and delegates to
+ * {@link ResultHandlers} for each element in turn.
+ *
+ * @author Eric Bottard
+ */
+@Component
+public class IterableResultHandler implements ResultHandler<Iterable> {
+
+	private ResultHandlers resultHandlers;
+
+	@Autowired
+	public void setResultHandlers(ResultHandlers resultHandlers) {
+		this.resultHandlers = resultHandlers;
+	}
+
+	@Override
+	public void handleResult(Iterable result) {
+		for (Object o : result) {
+			resultHandlers.handleResult(o);
+		}
+	}
+}

src/main/java/org/springframework/shell2/result/ResultHandler.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2015 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
+ *
+ *      http://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.shell2.result;
+
+/**
+ * Implementations know how to deal with results of method invocations, whether normal results or exceptions thrown.
+ *
+ * @author Eric Bottard
+ */
+public interface ResultHandler<T> {
+
+	/**
+	 * Deal with some method execution result, whether it was the normal return value, or some kind
+	 * of {@link Throwable}.
+	 */
+	void handleResult(T result);
+
+}

src/main/java/org/springframework/shell2/result/ResultHandlers.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2015 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
+ *
+ *      http://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.shell2.result;
+
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+/**
+ * A unique entry point delegating to the most appropriate {@link ResultHandler},
+ * according to the type of result to handle.
+ *
+ * @author Eric Bottard
+ */
+@Component
+public class ResultHandlers {
+
+	private Map<Class<?>, ResultHandler<?>> resultHandlers = new HashMap<>();
+
+	@SuppressWarnings("unchecked")
+	public void handleResult(Object result) {
+		Class<?> clazz = result == null ? null : result.getClass();
+		ResultHandler handler = getResultHandler(clazz);
+		handler.handleResult(result);
+	}
+
+	private ResultHandler getResultHandler(Class<?> clazz) {
+		ResultHandler handler = resultHandlers.get(clazz);
+		if (handler != null) {
+			return handler;
+		}
+		else {
+			for (Class type : clazz.getInterfaces()) {
+				handler = getResultHandler(type);
+				if (handler != null) {
+					return handler;
+				}
+			}
+			return clazz.getSuperclass() != null ? getResultHandler(clazz.getSuperclass()) : null;
+		}
+	}
+
+	@Autowired
+	public void setResultHandlers(Set<ResultHandler<?>> resultHandlers) {
+		for (ResultHandler<?> resultHandler : resultHandlers) {
+			Type type = ((ParameterizedType) resultHandler.getClass().getGenericInterfaces()[0]).getActualTypeArguments()[0];
+			this.resultHandlers.put((Class<?>) type, resultHandler);
+		}
+	}
+
+}

src/main/java/org/springframework/shell2/result/ThrowableResultHandler.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2015 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
+ *
+ *      http://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.shell2.result;
+
+import org.jline.utils.AttributedString;
+import org.jline.utils.AttributedStyle;
+
+import org.springframework.stereotype.Component;
+
+/**
+ * A {@link ResultHandler} that prints thrown exceptions messages in red.
+ *
+ * @author Eric Bottard
+ */
+@Component
+public class ThrowableResultHandler implements ResultHandler<Throwable> {
+
+	@Override
+	public void handleResult(Throwable result) {
+		System.out.println(new AttributedString(result.getMessage(),
+				AttributedStyle.DEFAULT.foreground(AttributedStyle.RED)).toAnsi());
+	}
+}