SyspathJavaLoader.java

// Copyright (c) Corporation for National Research Initiatives
// Copyright 2000 Samuele Pedroni

package org.python.core;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.StringTokenizer;
import java.util.zip.ZipEntry;

public class SyspathJavaLoader extends ClassLoader {

    private static final char SLASH_CHAR = '/';

    public InputStream getResourceAsStream(String res) {
        Py.writeDebug("resource", "trying resource: " + res);
        ClassLoader classLoader = Py.getSystemState().getClassLoader();
        if (classLoader != null) {
            return classLoader.getResourceAsStream(res);
        }

        classLoader = this.getClass().getClassLoader();

        InputStream ret;

        if (classLoader != null) {
            ret = classLoader.getResourceAsStream(res);
        } else {
            ret = ClassLoader.getSystemResourceAsStream(res);
        }
        if (ret != null) {
            return ret;
        }

        if (res.charAt(0) == SLASH_CHAR) {
            res = res.substring(1);
        }
        String entryRes = res;
        if (File.separatorChar != SLASH_CHAR) {
            res = res.replace(SLASH_CHAR, File.separatorChar);
            entryRes = entryRes.replace(File.separatorChar, SLASH_CHAR);
        }

        PyList path = Py.getSystemState().path;
        for (int i = 0; i < path.__len__(); i++) {
            PyObject entry = path.__getitem__(i);
            if (entry instanceof SyspathArchive) {
                SyspathArchive archive = (SyspathArchive) entry;
                ZipEntry ze = archive.getEntry(entryRes);
                if (ze != null) {
                    try {
                        return new ByteArrayInputStream(archive.getInputStream(ze));
                    } catch (IOException e) {
                        ;
                    }
                }
                continue;
            }
            String dir = entry.__str__().toString();
            if (dir.length() == 0) {
                dir = null;
            }
            try {
                return new BufferedInputStream(new FileInputStream(new File(dir, res)));
            } catch (IOException e) {
                continue;
            }
        }

        return null;
    }

    // override from abstract base class
    protected Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
        // First, if the Python runtime system has a default class loader,
        // defer to it.
        ClassLoader classLoader = Py.getSystemState().getClassLoader();
        if (classLoader != null) {
            return classLoader.loadClass(name);
        }

        // Search the sys.path for a .class file matching the named class.
        try {
            return Class.forName(name);
        } catch (ClassNotFoundException e) {
        }

        Class c = findLoadedClass(name);
        if (c != null) {
            return c;
        }

        PyList path = Py.getSystemState().path;
        for (int i = 0; i < path.__len__(); i++) {
            InputStream fis = null;
            File file = null;
            int size = 0;
            PyObject entry = path.__getitem__(i);
            if (entry instanceof SyspathArchive) {
                SyspathArchive archive = (SyspathArchive) entry;
                String entryname = name.replace('.', SLASH_CHAR) + ".class";
                ZipEntry ze = archive.getEntry(entryname);
                if (ze != null) {
                    try {
                        fis = new ByteArrayInputStream(archive.getInputStream(ze));
                        size = (int) ze.getSize();
                    } catch (IOException exc) {
                        ;
                    }
                }
            } else {
                String dir = entry.__str__().toString();
                file = getFile(dir, name);
                if (file != null) {
                    size = (int) file.length();
                    try {
                        fis = new FileInputStream(file);
                    } catch (FileNotFoundException e) {
                        ;
                    }
                }
            }
            if (fis == null) {
                continue;
            }
            try {
                byte[] buffer = new byte[size];
                int nread = 0;
                while (nread < size) {
                    nread += fis.read(buffer, nread, size - nread);
                }
                fis.close();
                return loadClassFromBytes(name, buffer);
            } catch (IOException e) {
                continue;
            } finally {
                try {
                    fis.close();
                } catch (IOException e) {
                    continue;
                }
            }
        }

        // couldn't find the .class file on sys.path
        throw new ClassNotFoundException(name);
    }

    private File getFile(String dir, String name) {
        String accum = "";
        boolean first = true;
        for (StringTokenizer t = new StringTokenizer(name, "."); t.hasMoreTokens();) {
            String token = t.nextToken();
            if (!first) {
                accum += File.separator;
            }
            accum += token;
            first = false;
        }
        if (dir.length() == 0) {
            dir = null;
        }
        return new File(dir, accum + ".class");
    }

    private Class loadClassFromBytes(String name, byte[] data) {
        // System.err.println("loadClassFromBytes("+name+", byte[])");
        Class c = defineClass(name, data, 0, data.length);
        resolveClass(c);
        // This method has caused much trouble. Using it breaks jdk1.2rc1
        // Not using it can make SUN's jdk1.1.6 JIT slightly unhappy.
        // Don't use by default, but allow python.options.compileClass to
        // override
        if (!Options.skipCompile) {
            // System.err.println("compile: "+name);
            Compiler.compileClass(c);
        }
        return c;
    }

}