obfuscation mapper

package lx01.projects.obmap;

import java.io.File;
import java.nio.file.Files;
import java.util.List;

import static lx01.projects.jd.JavaDecompiler.decompile;

public class ObfuscationMapper {
    public static void main (String[] args) {
        if (args.length < 4) throw new IllegalArgumentException ("Usage: \"java -jar [jar file] [file to be mapped] [file with mappings] [output file] [decompile (true or false)]\"");
        File sourceFile = new File(args[0]);
        File mappingsFile = new File(args[1]);
        File out = new File(args[2]);
        boolean decompile = args[3] == true;
        String source = decompile ? decompile(source) : concat(Files.readAllLines(source.toPath()));
        Mapping.Set mappings = readMappings(Files.readAllLines(mappingsFile.toPath()));
        Mapper.map(source, mappings, out);
    }

    private static String concat (List<String> strings) {
        String s = "";
        strings.forEach((s2) -> { s = s.concat(s2); });
        return s;
    }

    private static Mapping.Set readMappings (List<String> strings) {
        Mapping.Set mappings = new Mapping.Set();
        strings.forEach((s) -> { mappings.put(readMapping(s)); });
        return mappings;
    }

    private static Mapping readMapping (String mapping) {
        String[] m = mapping.split("->");
        return new Mapping.Builder().setTarget(m[0]).setResult(m[1]).build();
    }
}

//

package lx01.projects.obmap;

import java.util.Set;

public class Mapping {
    private String target;
    private String output;

    public Mapping () {}

    public void setTarget (String nt) {
        this.target = nt;
    }

    public String getTarget () {
        return this.target;
    }

    public void setOutput (String no) {
        this.output = no;
    }

    public String getOutput () {
        return this.output;
    }

    public static class Builder {
        private Mapping m = new Mapping();

        public Builder () {};

        public Builder setTarget (String nt) {
            this.m.setTarget(nt);
            return this;
        }

        public Builder setOutput (String no) {
            this.m.setOutput(no);
            return this;
        }
    }

    public static class Set {
        private Set<Mapping> mappings = Set.<Mapping>of();

        public Set () {}

        public void put (Mapping m) {
            this.mappings.put(m);
        }

        public boolean applies (String s) {
            for (Mapping m : this.mappings)
                if (s.contains(m.getTarget()))
                    return true;
            return false;
        }

        public String applyAll (String s) {
            for (Mapping m : this.mappings)
                if (s.contains(m.getTarget()))
                    s = s.replaceAll(m.getTarget(), m.getOutput());
            return s;
        }
    }
}

//

package lx01.projects.obmap;

public class Mapper {
    public static void map (String source, Mapping.Set mappings, File out) {
        try {
            new FileWriter(out).write(mappings.applyAll(s));
        } catch (Exception e) {
            return;
        }
    }
}