CleanUp
diff --git a/core/org.eclipse.statet.rj.data-tests/META-INF/MANIFEST.MF b/core/org.eclipse.statet.rj.data-tests/META-INF/MANIFEST.MF
index 85e5423..2e1a1f4 100644
--- a/core/org.eclipse.statet.rj.data-tests/META-INF/MANIFEST.MF
+++ b/core/org.eclipse.statet.rj.data-tests/META-INF/MANIFEST.MF
@@ -7,7 +7,7 @@
 Bundle-Name: StatET RJ - Data - Tests  (Incubation)
 Fragment-Host: org.eclipse.statet.rj.services.core
 Bundle-RequiredExecutionEnvironment: JavaSE-11
-Import-Package: org.junit.jupiter.api;version="5.6.0",
- org.junit.jupiter.api.function;version="5.6.0",
- org.junit.jupiter.params;version="5.6.0",
- org.junit.jupiter.params.provider;version="5.6.0"
+Import-Package: org.junit.jupiter.api;version="[5.6.0,6.0.0)",
+ org.junit.jupiter.api.function;version="[5.6.0,6.0.0)",
+ org.junit.jupiter.params;version="[5.6.0,6.0.0)",
+ org.junit.jupiter.params.provider;version="[5.6.0,6.0.0)"
diff --git a/core/org.eclipse.statet.rj.data/src/org/eclipse/statet/rj/data/impl/RCharacterFix64Store.java b/core/org.eclipse.statet.rj.data/src/org/eclipse/statet/rj/data/impl/RCharacterFix64Store.java
index 4bd1fe4..5026b53 100644
--- a/core/org.eclipse.statet.rj.data/src/org/eclipse/statet/rj/data/impl/RCharacterFix64Store.java
+++ b/core/org.eclipse.statet.rj.data/src/org/eclipse/statet/rj/data/impl/RCharacterFix64Store.java
@@ -156,7 +156,7 @@
 	@Override
 	public @Nullable String [] toArray() {
 		final int l= checkToArrayLength();
-		final var array= new @Nullable String[l];
+		final var array= new @Nullable String [l];
 		for (int i= 0, destIdx= 0; i < this.charValues.length; i++) {
 			final String[] chars= this.charValues[i];
 			System.arraycopy(chars, 0, array, destIdx, chars.length);
diff --git a/core/org.eclipse.statet.rj.data/src/org/eclipse/statet/rj/data/impl/RIntegerFix64Store.java b/core/org.eclipse.statet.rj.data/src/org/eclipse/statet/rj/data/impl/RIntegerFix64Store.java
index c9bb1ac..da5fffb 100644
--- a/core/org.eclipse.statet.rj.data/src/org/eclipse/statet/rj/data/impl/RIntegerFix64Store.java
+++ b/core/org.eclipse.statet.rj.data/src/org/eclipse/statet/rj/data/impl/RIntegerFix64Store.java
@@ -181,7 +181,7 @@
 	@Override
 	public @Nullable Integer [] toArray() {
 		final int l= checkToArrayLength();
-		final var array= new @Nullable Integer[l];
+		final var array= new @Nullable Integer [l];
 		for (int i= 0, destIdx= 0; i < this.intValues.length; i++) {
 			final int[] ints= this.intValues[i];
 			for (int j= 0; j < ints.length; j++, destIdx++) {
diff --git a/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/BinExchange.java b/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/BinExchange.java
index 2c54f29..d94d7a7 100644
--- a/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/BinExchange.java
+++ b/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/BinExchange.java
@@ -114,7 +114,7 @@
 		if (path == null || out == null || ref == null) {
 			throw new NullPointerException();
 		}
-		if (path.length() == 0) {
+		if (path.isEmpty()) {
 			throw new IllegalArgumentException("Illegal path argument.");
 		}
 		
@@ -135,7 +135,7 @@
 		if (path == null || ref == null) {
 			throw new NullPointerException();
 		}
-		if (path.length() == 0) {
+		if (path.isEmpty()) {
 			throw new IllegalArgumentException("Illegal path argument.");
 		}
 		
diff --git a/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/srv/CliUtil.java b/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/srv/CliUtil.java
index 46f2d26..48e472f 100644
--- a/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/srv/CliUtil.java
+++ b/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/srv/CliUtil.java
@@ -58,7 +58,7 @@
 		this.options= new HashMap<>();
 		while (idx < args.length) {
 			final String arg= args[idx++];
-			if (arg.length() == 0 || arg.charAt(0) != '-') {
+			if (arg.isEmpty() || arg.charAt(0) != '-') {
 				continue;
 			}
 			final int split= arg.indexOf('=');
diff --git a/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/srvext/auth/SimpleNamePassAuthMethod.java b/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/srvext/auth/SimpleNamePassAuthMethod.java
index aa5e017..78c95b3 100644
--- a/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/srvext/auth/SimpleNamePassAuthMethod.java
+++ b/core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/srvext/auth/SimpleNamePassAuthMethod.java
@@ -84,7 +84,7 @@
 		final Properties read= new Properties();
 		if (config.getKey().equals("file")) {
 			final String fileName= config.getValue();
-			if (fileName == null || fileName.length() == 0) {
+			if (fileName == null || fileName.isEmpty()) {
 				throw new RjException("Missing password file name.", null);
 			}
 			final File file= new File(fileName);
diff --git a/core/org.eclipse.statet.rj.services.core/srcGraphic/org/eclipse/statet/rj/graphic/core/util/CodeGenAdbSymbol.java b/core/org.eclipse.statet.rj.services.core/srcGraphic/org/eclipse/statet/rj/graphic/core/util/CodeGenAdbSymbol.java
index dc9a0c8..af5e354 100644
--- a/core/org.eclipse.statet.rj.services.core/srcGraphic/org/eclipse/statet/rj/graphic/core/util/CodeGenAdbSymbol.java
+++ b/core/org.eclipse.statet.rj.services.core/srcGraphic/org/eclipse/statet/rj/graphic/core/util/CodeGenAdbSymbol.java
@@ -33,7 +33,7 @@
 		final BufferedReader reader= new BufferedReader(new FileReader(file));
 		String line;
 		while ((line= reader.readLine()) != null) {
-			if (line.length() == 0 || line.startsWith("#")) {
+			if (line.isEmpty() || line.startsWith("#")) {
 				continue;
 			}
 			final String[] columns= line.split("\t");
diff --git a/eclient/org.eclipse.statet.rj.eclient.core/srcRSetups/org/eclipse/statet/rj/rsetups/RSetupUtil.java b/eclient/org.eclipse.statet.rj.eclient.core/srcRSetups/org/eclipse/statet/rj/rsetups/RSetupUtil.java
index d305149..b9bab33 100644
--- a/eclient/org.eclipse.statet.rj.eclient.core/srcRSetups/org/eclipse/statet/rj/rsetups/RSetupUtil.java
+++ b/eclient/org.eclipse.statet.rj.eclient.core/srcRSetups/org/eclipse/statet/rj/rsetups/RSetupUtil.java
@@ -171,7 +171,7 @@
 					continue;
 				}
 				final String groupId= element.getAttribute(GROUP_ATTRIBUTE_NAME);
-				if (groupId == null || groupId.length() == 0 || groupId.equals("R_LIBS")) { //$NON-NLS-1$
+				if (groupId == null || groupId.isEmpty() || groupId.equals("R_LIBS")) { //$NON-NLS-1$
 					setup.getRLibs().add(path);
 				}
 				else if (groupId.equals("R_LIBS_SITE")) { //$NON-NLS-1$
diff --git a/eclient/org.eclipse.statet.rj.eclient.graphics/src/org/eclipse/statet/internal/rj/eclient/graphics/EclipseRGraphic.java b/eclient/org.eclipse.statet.rj.eclient.graphics/src/org/eclipse/statet/internal/rj/eclient/graphics/EclipseRGraphic.java
index 7298242..8bd78e4 100644
--- a/eclient/org.eclipse.statet.rj.eclient.graphics/src/org/eclipse/statet/internal/rj/eclient/graphics/EclipseRGraphic.java
+++ b/eclient/org.eclipse.statet.rj.eclient.graphics/src/org/eclipse/statet/internal/rj/eclient/graphics/EclipseRGraphic.java
@@ -757,7 +757,7 @@
 	}
 	
 	private String getFontName(final String family) {
-		if (family.length() == 0 || family.equals("sansserif")) {
+		if (family.isEmpty() || family.equals("sansserif")) {
 			return this.sansFontName;
 		}
 		else if (family.equals("serif")) {
diff --git a/servi/org.eclipse.statet.rj.servi/src/org/eclipse/statet/internal/rj/servi/LocalNodeFactory.java b/servi/org.eclipse.statet.rj.servi/src/org/eclipse/statet/internal/rj/servi/LocalNodeFactory.java
index 136df06..a152644 100644
--- a/servi/org.eclipse.statet.rj.servi/src/org/eclipse/statet/internal/rj/servi/LocalNodeFactory.java
+++ b/servi/org.eclipse.statet.rj.servi/src/org/eclipse/statet/internal/rj/servi/LocalNodeFactory.java
@@ -172,9 +172,9 @@
 		// R home
 		final String rHomeString;
 		{	String value= config.getRHome();
-			if (value == null || value.length() == 0) {
+			if (value == null || value.isEmpty()) {
 				value= config.getEnvironmentVariables().get("R_HOME");
-				if (value == null || value.length() == 0) {
+				if (value == null || value.isEmpty()) {
 					this.errorMessage= "Missing value for R_HOME.";
 					throw new RjInvalidConfigurationException(this.errorMessage);
 				}
@@ -211,7 +211,7 @@
 		
 		// Java
 		String javaHome= config.getJavaHome();
-		if (javaHome == null || javaHome.length() == 0) {
+		if (javaHome == null || javaHome.isEmpty()) {
 			javaHome= nonNullAssert(System.getProperty("java.home"));
 		}
 		p.addEnv.put("JAVA_HOME", javaHome);
@@ -294,7 +294,7 @@
 		}
 		
 		String rArch= config.getRArch();
-		if (rArch != null && rArch.length() == 0) {
+		if (rArch != null && rArch.isEmpty()) {
 			rArch= null;
 		}
 		boolean rArchAuto= false;
diff --git a/servi/org.eclipse.statet.rj.servi/src/org/eclipse/statet/rj/servi/node/RServiNodeConfig.java b/servi/org.eclipse.statet.rj.servi/src/org/eclipse/statet/rj/servi/node/RServiNodeConfig.java
index a76d02e..605f7e1 100644
--- a/servi/org.eclipse.statet.rj.servi/src/org/eclipse/statet/rj/servi/node/RServiNodeConfig.java
+++ b/servi/org.eclipse.statet.rj.servi/src/org/eclipse/statet/rj/servi/node/RServiNodeConfig.java
@@ -157,7 +157,7 @@
 		setRArch(map.getProperty(R_ARCH_ID));
 		setJavaHome(map.getProperty(JAVA_HOME_ID));
 		setJavaArgs(map.getProperty(JAVA_ARGS_ID));
-		if (this.javaArgs.length() == 0) {
+		if (this.javaArgs.isEmpty()) {
 			setJavaArgs(map.getProperty(JAVA_ARGS_OLD_ID));
 		}
 		this.environmentVariables.clear();
diff --git a/servi/org.eclipse.statet.rj.servi/srcServiPool/org/eclipse/statet/rj/servi/pool/NetConfig.java b/servi/org.eclipse.statet.rj.servi/srcServiPool/org/eclipse/statet/rj/servi/pool/NetConfig.java
index f4b4193..63fae88 100644
--- a/servi/org.eclipse.statet.rj.servi/srcServiPool/org/eclipse/statet/rj/servi/pool/NetConfig.java
+++ b/servi/org.eclipse.statet.rj.servi/srcServiPool/org/eclipse/statet/rj/servi/pool/NetConfig.java
@@ -215,7 +215,7 @@
 		boolean valid= true;
 		
 		String effective= this.hostAddress;
-		if (effective == null || effective.length() == 0) {
+		if (effective == null || effective.isEmpty()) {
 			effective= System.getProperty("java.rmi.server.hostname");
 		}
 		try {