org.springframework.tooling.jdt.ls.commons.java.JavaCodeCompletionUtils.java Source code

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Here is the source code for org.springframework.tooling.jdt.ls.commons.java.JavaCodeCompletionUtils.java

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/*******************************************************************************
 * Copyright (c) 2019 Pivotal, Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Pivotal, Inc. - initial API and implementation
 *******************************************************************************/
package org.springframework.tooling.jdt.ls.commons.java;

import org.eclipse.jdt.core.IBuffer;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IPackageFragment;
import org.eclipse.jdt.core.IPackageFragmentRoot;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.internal.core.DefaultWorkingCopyOwner;

/**
 * @author Martin Lippert
 */
@SuppressWarnings("restriction")
public class JavaCodeCompletionUtils {

    public static final String CLASS_NAME = "_xxx";

    private static final String CLASS_SOURCE_START = "public class " + CLASS_NAME + " {\n"
            + "    public void main(String[] args) {\n" + "        ";

    private static final String CLASS_SOURCE_END = "\n" + "    }\n" + "}";

    public static void codeComplete(IJavaProject project, String prefix,
            JavaCodeCompletionProposalCollector proposalCollector) {
        if (prefix == null || prefix.length() == 0) {
            return;
        }

        try {
            ICompilationUnit unit = createCompilationUnit(project, prefix);

            prefix = prefix.replace('$', '.');

            String sourceStart = CLASS_SOURCE_START + prefix;
            String packageName = null;

            int dot = prefix.lastIndexOf('.');
            if (dot > -1) {
                packageName = prefix.substring(0, dot);
                sourceStart = "package " + packageName + ";\n" + sourceStart;
            }

            String source = sourceStart + CLASS_SOURCE_END;
            setContents(unit, source);

            unit.codeComplete(sourceStart.length(), proposalCollector, DefaultWorkingCopyOwner.PRIMARY);
        } catch (Exception e) {
            // do nothing
        }
    }

    private static ICompilationUnit createCompilationUnit(IJavaProject project, String prefix)
            throws JavaModelException {
        IPackageFragment root = getPackageFragment(project, prefix);
        ICompilationUnit unit = root.getCompilationUnit("_xxx.java").getWorkingCopy(null);
        return unit;
    }

    private static IPackageFragment getPackageFragment(IJavaProject project, String prefix)
            throws JavaModelException {
        int dot = prefix.lastIndexOf('.');
        if (dot > -1) {
            String packageName = prefix.substring(0, dot);
            for (IPackageFragmentRoot root : project.getPackageFragmentRoots()) {
                IPackageFragment p = root.getPackageFragment(packageName);
                if (p != null && p.exists()) {
                    return p;
                }
            }
            IPackageFragment[] packages = project.getPackageFragments();
            for (IPackageFragment p : packages) {
                if (p.getElementName().equals(packageName))
                    return p;
            }
        } else {
            for (IPackageFragmentRoot p : project.getAllPackageFragmentRoots()) {
                if (p.getKind() == IPackageFragmentRoot.K_SOURCE) {
                    return p.getPackageFragment("");
                }
            }
        }
        return project.getPackageFragments()[0];
    }

    private static void setContents(ICompilationUnit cu, String source) {
        if (cu == null)
            return;

        synchronized (cu) {
            IBuffer buffer;
            try {

                buffer = cu.getBuffer();
            } catch (JavaModelException e) {
                e.printStackTrace();
                buffer = null;
            }

            if (buffer != null)
                buffer.setContents(source);
        }
    }

}