dk.nversion.copybook.codegen.CopyBookConverter Maven / Gradle / Ivy

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package dk.nversion.copybook.codegen;

import dk.nversion.ByteUtils;
import jdk.nashorn.api.scripting.ScriptObjectMirror;
import jdk.nashorn.api.scripting.ScriptUtils;

import javax.script.*;
import java.io.*;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.nio.charset.StandardCharsets;
import java.nio.file.*;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

public class CopyBookConverter {
    private final ScriptEngineManager manager;
    private ScriptEngine engine;
    private final Invocable invocable;
    static Pattern re_className = Pattern.compile("^.*?\\s(?:class|@interface|enum)\\s*([^\\s]+)", Pattern.DOTALL);


    public CopyBookConverter() throws Exception {
        InputStream inputStream = this.getClass().getResourceAsStream("classconverter.html");
        String js = extractJS(inputStream);

        manager = new ScriptEngineManager();
        engine = manager.getEngineByName("nashorn");

        if(engine == null) {
            throw new Exception("Could not load the Nashorn script engine");
        }

        invocable = (Invocable) engine;
        engine.eval(js);
    }

    public void convertFiles(String inputPath, Pattern pattern, String outputPath, String packageRootName, String accessor, String charset, String subClassHandling) throws Exception {
        File inputFile = new File(inputPath);
        inputPath = inputFile.getCanonicalPath();
        List inputFiles = new ArrayList<>();

        if(inputFile.isDirectory()) {
             inputFiles = Files.walk(inputFile.toPath())
                    .filter(p -> pattern.matcher(p.toString()).find() && Files.isRegularFile(p))
                    .map(Path::toFile)
                    .collect(Collectors.toList());

        } else if (inputFile.isFile()) {
            inputFiles.add(inputFile);
        }

        for(File inFile : inputFiles) {
            String packageName = inFile.getCanonicalFile().getParent().substring(inputPath.length()).replace('\\', '.').replace('/', '.').replace('_', '.');
            packageName = packageName.isEmpty() ? packageRootName : packageRootName + "." + packageName.substring(1);
            String rootClassName = getClassNameFromFile(inFile);
            List outClasses = convert(new FileInputStream(inFile), packageName, rootClassName, accessor, charset, subClassHandling, rootClassName);
            for(String outClass : outClasses) {
                Matcher classNameMatcher = re_className.matcher(outClass);
                if (classNameMatcher.find()) {
                    String className = classNameMatcher.group(1);
                    Path outPath = Paths.get(outputPath, packageName.replace('.', '/'),className + ".java");
                    outPath.getParent().toFile().mkdirs();
                    System.out.println("  " + outPath);
                    Files.write(outPath, outClass.getBytes(StandardCharsets.UTF_8));
                }
            }
        }
    }

    public List convert(String copybookString, String packageName, String rootClassName, String accessor, String charset, String subClassHandling, String wrapperClassName) throws Exception {
        ScriptObjectMirror results = (ScriptObjectMirror) invocable.invokeFunction("convertCopybook", packageName, rootClassName, copybookString, accessor, charset, subClassHandling, wrapperClassName);
        return Arrays.asList(results.values().toArray(new String[results.size()]));
    }

    public List convert(InputStream copybookStream, String packageName, String rootClassName, String accessor, String charset, String subClassHandling, String wrapperClassName) throws Exception {
        return convert(new String(ByteUtils.toByteArray(copybookStream), StandardCharsets.UTF_8), packageName, rootClassName, accessor, charset, subClassHandling, wrapperClassName);
    }

    private String extractJS(InputStream inputStream) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        StringBuilder builder = new StringBuilder();
        String str;
        boolean capture = false;
        int whiteSpaceOffset = 0;
        while ((str = bufferedReader.readLine()) != null) {
            if(str.indexOf("/*** convertCopybook stop ***/") > 0) {
                capture = false;
            }

            if(capture) {
                builder.append(str.substring(str.length() > whiteSpaceOffset ? whiteSpaceOffset : 0) + "\n");
            }

            if(str.indexOf("/*** convertCopybook start ***/") > 0) {
                while (whiteSpaceOffset < str.length() && Character.isWhitespace(str.charAt(whiteSpaceOffset))) {
                    whiteSpaceOffset++;
                }
                capture = true;
            }
        }
        return builder.toString();
    }

    private String getClassNameFromFile(File file)
    {
        String className = file.getName();
        int i = className.lastIndexOf('.');
        if (i > 0) {
            className = className.substring(0, i);
        }
        try {
            className = (String) invocable.invokeFunction("toClassName", className);

        } catch (ScriptException | NoSuchMethodException e) {
            e.printStackTrace();
        }
        return className;
    }
}