Provide a Java process command builder.

org.eclipse.lsp4e/src/org/eclipse/lsp4e/server/java/JavaProcessCommandBuilder.java

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+/*******************************************************************************
+ * Copyright (c) 2023 Red Hat Inc. and others.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *  Angelo ZERR (Red Hat Inc.) - initial implementation
+ *******************************************************************************/
+package org.eclipse.lsp4e.server.java;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.eclipse.core.runtime.Platform;
+
+/**
+ * A builder to create Java process command.
+ */
+public class JavaProcessCommandBuilder {
+
+    private String javaPath;
+
+    private String debugPort;
+
+    private boolean debugSuspend;
+    private String jar;
+
+    private String cp;
+
+    public JavaProcessCommandBuilder() {
+        setJavaPath(computeJavaPath());
+    }
+
+    public JavaProcessCommandBuilder setJavaPath(String javaPath) {
+        this.javaPath = javaPath;
+        return this;
+    }
+
+    public JavaProcessCommandBuilder setDebugPort(String debugPort) {
+        this.debugPort = debugPort;
+        return this;
+    }
+
+    public JavaProcessCommandBuilder setDebugSuspend(boolean debugSuspend) {
+        this.debugSuspend = debugSuspend;
+        return this;
+    }
+
+    public JavaProcessCommandBuilder setJar(String jar) {
+        this.jar = jar;
+        return this;
+    }
+
+    public JavaProcessCommandBuilder setCp(String cp) {
+        this.cp = cp;
+        return this;
+    }
+
+    public List<String> create() {
+        List<String> commands = new ArrayList<>();
+        commands.add(javaPath);
+        if (debugPort != null && !debugPort.isEmpty()) {
+            String suspend = debugSuspend ? "y" : "n"; //$NON-NLS-1$ //$NON-NLS-2$
+            commands.add("-agentlib:jdwp=transport=dt_socket,server=y,suspend=" + suspend + ",address=" + debugPort); //$NON-NLS-1$ //$NON-NLS-2$
+        }
+        if (jar != null) {
+            commands.add("-jar"); //$NON-NLS-1$
+            commands.add(jar);
+        }
+        if (cp != null) {
+            commands.add("-cp"); //$NON-NLS-1$
+            commands.add(cp);
+        }
+        return commands;
+    }
+
+    private static String computeJavaPath() {
+    	return new File(System.getProperty("java.home"), //$NON-NLS-1$
+				"bin/java" + (Platform.getOS().equals(Platform.OS_WIN32) ? ".exe" : "")).getAbsolutePath(); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+    }
+}