Add additional exclude property

The default value of `spring.devtools.restart.exclude` is quite long and
any override requires to copy/paste it to add additional exclusions. To
avoid that, a new `spring.devtools.restart.additional-exclude` property
has been added.

Both properties are now used to compute the full list of exclusions that
is used by PatternClassPathRestartStrategy.

Closes gh-3774

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/autoconfigure/DevToolsProperties.java

@@ -22,6 +22,7 @@ import java.util.List;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.NestedConfigurationProperty;
+import org.springframework.util.StringUtils;
 
 /**
  * Configuration properties for developer tools.
@@ -71,10 +72,15 @@ public class DevToolsProperties {
 		private boolean enabled = true;
 
 		/**
-		 * Patterns that should be excluding for triggering a full restart.
+		 * Patterns that should be excluded from triggering a full restart.
 		 */
 		private String exclude = DEFAULT_RESTART_EXCLUDES;
 
+		/**
+		 * Additional patterns that should be excluded from triggering a full restart.
+		 */
+		private String additionalExclude;
+
 		/**
 		 * Amount of time (in milliseconds) to wait between polling for classpath changes.
 		 */
@@ -105,6 +111,17 @@ public class DevToolsProperties {
 			this.enabled = enabled;
 		}
 
+		public String[] getAllExclude() {
+			List<String> allExclude = new ArrayList<String>();
+			if (StringUtils.hasText(this.exclude)) {
+				allExclude.addAll(StringUtils.commaDelimitedListToSet(this.exclude));
+			}
+			if (StringUtils.hasText(this.additionalExclude)) {
+				allExclude.addAll(StringUtils.commaDelimitedListToSet(this.additionalExclude));
+			}
+			return allExclude.toArray(new String[allExclude.size()]);
+		}
+
 		public String getExclude() {
 			return this.exclude;
 		}
@@ -113,6 +130,14 @@ public class DevToolsProperties {
 			this.exclude = exclude;
 		}
 
+		public String getAdditionalExclude() {
+			return this.additionalExclude;
+		}
+
+		public void setAdditionalExclude(String additionalExclude) {
+			this.additionalExclude = additionalExclude;
+		}
+
 		public long getPollInterval() {
 			return this.pollInterval;
 		}

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/autoconfigure/LocalDevToolsAutoConfiguration.java

@@ -123,7 +123,7 @@ public class LocalDevToolsAutoConfiguration {
 		@ConditionalOnMissingBean
 		public ClassPathRestartStrategy classPathRestartStrategy() {
 			return new PatternClassPathRestartStrategy(this.properties.getRestart()
-					.getExclude());
+					.getAllExclude());
 		}
 
 		@Bean

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/classpath/PatternClassPathRestartStrategy.java

@@ -33,9 +33,12 @@ public class PatternClassPathRestartStrategy implements ClassPathRestartStrategy
 
 	private final String[] excludePatterns;
 
+	public PatternClassPathRestartStrategy(String[] excludePatterns) {
+		this.excludePatterns = excludePatterns;
+	}
+
 	public PatternClassPathRestartStrategy(String excludePatterns) {
-		this.excludePatterns = StringUtils
-				.commaDelimitedListToStringArray(excludePatterns);
+		this(StringUtils.commaDelimitedListToStringArray(excludePatterns));
 	}
 
 	@Override

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/remote/client/RemoteClientConfiguration.java

@@ -214,7 +214,7 @@ public class RemoteClientConfiguration {
 		@Bean
 		public ClassPathRestartStrategy classPathRestartStrategy() {
 			return new PatternClassPathRestartStrategy(this.properties.getRestart()
-					.getExclude());
+					.getAllExclude());
 		}
 
 		@Bean

spring-boot-devtools/src/test/java/org/springframework/boot/devtools/autoconfigure/DevToolsPropertiesTests.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2012-2015 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.boot.devtools.autoconfigure;
+
+import org.junit.Test;
+
+import static org.hamcrest.Matchers.arrayContaining;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Tests for {@link DevToolsProperties}.
+ *
+ * @author Stephane Nicoll
+ */
+public class DevToolsPropertiesTests {
+
+	private final DevToolsProperties devToolsProperties = new DevToolsProperties();
+
+	@Test
+	public void additionalExcludeKeepsDefaults() {
+		DevToolsProperties.Restart restart = this.devToolsProperties.getRestart();
+		restart.setAdditionalExclude("foo/**,bar/**");
+		assertThat(restart.getAllExclude(), arrayContaining("META-INF/maven/**",
+				"META-INF/resources/**", "resources/**", "static/**", "public/**",
+				"templates/**", "foo/**", "bar/**"));
+	}
+
+	@Test
+	public void additionalExcludeNoDefault() {
+		DevToolsProperties.Restart restart = this.devToolsProperties.getRestart();
+		restart.setExclude("");
+		restart.setAdditionalExclude("foo/**,bar/**");
+		assertThat(restart.getAllExclude(), arrayContaining("foo/**", "bar/**"));
+	}
+
+	@Test
+	public void additionalExcludeCustomDefault() {
+		DevToolsProperties.Restart restart = this.devToolsProperties.getRestart();
+		restart.setExclude("biz/**");
+		restart.setAdditionalExclude("foo/**,bar/**");
+		assertThat(restart.getAllExclude(), arrayContaining("biz/**", "foo/**", "bar/**"));
+	}
+
+}