Why does JD-GUI prefix every line with a comment and line number?

Question

I've encountered this problem several times. Whenever I decompile something and save all the sources using JD-GUI, it prefixes each line with a block comment and inserts line numbers for code in the body of methods. Here is an example from a jar I just decompiled:

/*    */   public void onEnable()
/*    */   {
/* 25 */     List DropList = new ArrayList();
/* 26 */     DropList.add(Integer.valueOf(264));
/* 27 */     DropList.add(Integer.valueOf(57));
/* 28 */     DropList.add(Integer.valueOf(278));
/*    */ 
/* 30 */     this.config = getConfig();
/*    */ 
/* 32 */     this.config.addDefault("GiftDrops", DropList);
/* 33 */     this.config.addDefault("DropRate", Integer.valueOf(0));
/* 34 */     this.config.addDefault("GiftBoxPlayerSkin", "lol768");
/* 35 */     this.config.addDefault("CraftingRecipe.LineOne", "339,339,339");
/* 36 */     this.config.addDefault("CraftingRecipe.LineTwo", "339,264,339");
/* 37 */     this.config.addDefault("CraftingRecipe.LineThree", "339,339,339");
/*    */ 
/* 39 */     this.config.options().copyDefaults(true);
/* 40 */     saveConfig();
/*    */ 
/* 43 */     SkullMeta giftboxskull = (SkullMeta)this.giftbox.getItemMeta();
/*    */ 
/* 45 */     giftboxskull.setOwner(this.config.getString("GiftBoxPlayerSkin"));
/* 46 */     giftboxskull.setDisplayName(ChatColor.GREEN + "Gift Box");
/* 47 */     this.giftbox.setItemMeta(giftboxskull);
/*    */ 
/* 49 */     this.giftboxrecipe = new ShapedRecipe(this.giftbox);
/* 50 */     this.giftboxrecipe.shape(new String[] { "123", "456", "789" });
/*    */ 
/* 52 */     String[] LineOne = getConfig().getString("CraftingRecipe.LineOne").split(",");
/* 53 */     String[] LineTwo = getConfig().getString("CraftingRecipe.LineTwo").split(",");
/* 54 */     String[] LineThree = getConfig().getString("CraftingRecipe.LineThree").split(",");
/*    */ 
/* 56 */     this.giftboxrecipe.setIngredient('1', new ItemStack(Integer.parseInt(LineOne[0])).getData());
/* 57 */     this.giftboxrecipe.setIngredient('2', new ItemStack(Integer.parseInt(LineOne[1])).getData());
/* 58 */     this.giftboxrecipe.setIngredient('3', new ItemStack(Integer.parseInt(LineOne[2])).getData());
/* 59 */     this.giftboxrecipe.setIngredient('4', new ItemStack(Integer.parseInt(LineTwo[0])).getData());
/* 60 */     this.giftboxrecipe.setIngredient('5', new ItemStack(Integer.parseInt(LineTwo[1])).getData());
/* 61 */     this.giftboxrecipe.setIngredient('6', new ItemStack(Integer.parseInt(LineTwo[2])).getData());
/* 62 */     this.giftboxrecipe.setIngredient('7', new ItemStack(Integer.parseInt(LineThree[0])).getData());
/* 63 */     this.giftboxrecipe.setIngredient('8', new ItemStack(Integer.parseInt(LineThree[1])).getData());
/* 64 */     this.giftboxrecipe.setIngredient('9', new ItemStack(Integer.parseInt(LineThree[2])).getData());
/*    */ 
/* 66 */     getServer().addRecipe(this.giftboxrecipe);
/*    */ 
/* 68 */     getServer().getPluginManager().registerEvents(new GiftBoxEventListener(this), this);
/*    */   }

This seems to be a feature JD-GUI has to stop people from using the source files they obtain by compiling. I can fairly easily remove all of these comments using a bash command, but it's still an annoyance. Is there a way to disable this functionality?

Ratal

I'm curious: why do you call it a "problem" and jump to such an uncharitable conclusion? First of all: it doesn't stop you from compiling the files; they compile fine even with the comments there. And why would JD-GUI even care whether you compile the sources it creates? They aren't their sources. It's pretty obvious to me why it does it: because it's convenient, especially for debugging. Stack traces and debug info contain line numbers, and it can be extremely useful to know on which line of third party code an exception occurred or the program pointer is located during debugging... – Pungy

I agree it is annoying some times. For instance if you want to decompile 2 versions of the same jar and compare them using a merge tool. A single extra line in one class file will cause every line in the files to show as different. Zufuliu's answer really helps me! – Unlike

Answer 1

In "Help" -> "Preferences", under "Sources saving" group, uncheck "Display line numbers"

Axe

Thanks, this worked. I saw this option earlier but thought it was for the line numbers displayed next to the code in the GUI and not the line numbers in the saved sources. – Ratal

who thought that preferences would be in help menu !!!!!!! thanks for the tip – Munitions