CoreModMaker.java

package com.thedeviantnetwork.deviantfix.patcher;

import org.apache.commons.io.IOUtils;

import java.io.*;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipOutputStream;

public class CoreModMaker {

    private List<File> coremods = new ArrayList<File>();

    public void addMod(File mod){
        coremods.add(mod);
    }
    private boolean didPatch = false;

    public void addMod(String file){
        if (file.contains("*")) {
            file = file.substring(0, file.length() - 1).replace("mods/","");
            File folder = new File("mods/");
            for (File f : folder.listFiles()) {
                if (f.getName().startsWith(file)) {
                    addMod(f);
                    return;
                }
            }
        }
        else {
            addMod(new File("mods/" + file + ".jar"));
        }
    }

    private void bake(File file){
        try {
            System.out.println("Patching... " + file);
            ZipFile zip = new ZipFile(file);
            File zipTemp = new File("out.tmp");
            zipTemp.deleteOnExit();
            ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(zipTemp));
            String toModify = "META-INF/MANIFEST.MF";

            Enumeration<? extends ZipEntry> entities = zip.entries();
            int needpatch = 2;

            while (entities.hasMoreElements()) {
                ZipEntry e = entities.nextElement();
                zos.putNextEntry(new ZipEntry(e.getName()));
                if(!e.getName().equalsIgnoreCase(toModify)) {
                    byte[] bytes = IOUtils.toByteArray(zip.getInputStream(e));
                    zos.write(bytes, 0, bytes.length);
                } else {
                    BufferedReader reader = new BufferedReader(new InputStreamReader(zip.getInputStream(e)));
                    BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(zos));
                    while (reader.ready()) {
                        String line = reader.readLine();
                        if (line.contains("FMLCorePlugin"))
                            needpatch--;
                        if (line.length() > 0)
                            writer.write(line + "\n");
                    }
                    if (needpatch != 0) {
                        writer.write(   "FMLCorePlugin: com.thedeviantnetwork.deviantfix.patcher.FakeCoremod\n" +
                                        "FMLCorePluginContainsFMLMod: true\n");
                        writer.flush();
                    }
                }
                zos.closeEntry();
            }
            zos.close();
            zip.close();
            if (needpatch != 0){
                file.delete();
                System.out.println(zipTemp.renameTo(file));
                System.out.println("Patched: " + file);
                didPatch = true;
            }else {
                zipTemp.delete();
                System.out.println(file + " Already Patched!");
            }

        } catch (IOException e1) {
            e1.printStackTrace();
        }
    }

    public void bakeCoreMods(){
        for (File mod : coremods)
            bake(mod);
    }

    public boolean didPatch() {
        return didPatch;
    }
}