com.twosigma.beaker.autocomplete.ClasspathScanner.java Source code

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Here is the source code for com.twosigma.beaker.autocomplete.ClasspathScanner.java

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/*
 *  Copyright 2014 TWO SIGMA OPEN SOURCE, LLC
 *
 *  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 com.twosigma.beaker.autocomplete;

import org.apache.commons.lang3.StringUtils;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.Manifest;

public class ClasspathScanner {
    protected Map<String, List<String>> packages;

    public ClasspathScanner() {
        packages = new HashMap<String, List<String>>();
        String classpath = System.getProperty("java.class.path");
        scanClasses(classpath);
    }

    public ClasspathScanner(String classpath) {
        packages = new HashMap<String, List<String>>();
        scanClasses(classpath);
    }

    public Set<String> getPackages() {
        return packages.keySet();
    }

    public List<String> getClasses(String p) {
        if (packages.containsKey(p))
            return packages.get(p);
        return null;
    }

    private void scanClasses(String classpath) {
        String[] paths = classpath.split(System.getProperty("path.separator"));

        String javaHome = System.getProperty("java.home");
        File file = new File(javaHome + File.separator + "lib");
        if (file.exists()) {
            findClasses(file, file, true);
        }

        for (String path : paths) {
            file = new File(path);
            if (file.exists()) {
                findClasses(file, file, true);
            }
        }
    }

    private boolean findClasses(File root, File file, boolean includeJars) {
        if (file != null && file.isDirectory()) {
            File[] lf = file.listFiles();
            if (lf != null)
                for (File child : lf) {
                    if (!findClasses(root, child, includeJars)) {
                        return false;
                    }
                }
        } else {
            if (file.getName().toLowerCase().endsWith(".jar") && includeJars) {
                JarFile jar = null;
                try {
                    jar = new JarFile(file);
                } catch (Exception ex) {
                }
                if (jar != null) {
                    try {
                        Manifest mf = jar.getManifest();
                        if (mf != null) {
                            String cp = mf.getMainAttributes().getValue("Class-Path");
                            if (StringUtils.isNotEmpty(cp)) {
                                for (String fn : cp.split(" ")) {
                                    File child = new File(
                                            file.getParent() + System.getProperty("file.separator") + fn);
                                    if (child.getAbsolutePath().equals(jar.getName())) {
                                        continue; //skip bad jars, that contain references to themselves in MANIFEST.MF
                                    }
                                    if (child.exists()) {
                                        if (!findClasses(root, child, includeJars)) {
                                            return false;
                                        }
                                    }
                                }
                            }
                        }
                    } catch (IOException e) {
                    }

                    Enumeration<JarEntry> entries = jar.entries();
                    while (entries.hasMoreElements()) {
                        JarEntry entry = entries.nextElement();
                        String name = entry.getName();
                        int extIndex = name.lastIndexOf(".class");
                        if (extIndex > 0 && !name.contains("$")) {
                            String cname = name.substring(0, extIndex).replace("/", ".");
                            int pIndex = cname.lastIndexOf('.');
                            if (pIndex > 0) {
                                String pname = cname.substring(0, pIndex);
                                cname = cname.substring(pIndex + 1);
                                if (!packages.containsKey(pname))
                                    packages.put(pname, new ArrayList<String>());
                                packages.get(pname).add(cname);
                            }
                        }
                    }
                }
            } else if (file.getName().toLowerCase().endsWith(".class")) {
                String cname = createClassName(root, file);
                if (!cname.contains("$")) {
                    int pIndex = cname.lastIndexOf('.');
                    if (pIndex > 0) {
                        String pname = cname.substring(0, pIndex + 1);
                        cname = cname.substring(pIndex);
                        if (!packages.containsKey(pname))
                            packages.put(pname, new ArrayList<String>());
                        packages.get(pname).add(cname);
                    }
                }
            } else {
                examineFile(root, file);
            }
        }

        return true;
    }

    /*
     * extension hook for languages that generate classes on the fly
     */
    protected void examineFile(File root, File file) {

    }

    private String createClassName(File root, File file) {
        StringBuffer sb = new StringBuffer();
        String fileName = file.getName();
        sb.append(fileName.substring(0, fileName.lastIndexOf(".class")));
        file = file.getParentFile();
        while (file != null && !file.equals(root)) {
            sb.insert(0, '.').insert(0, file.getName());
            file = file.getParentFile();
        }
        return sb.toString();
    }

}