操作系统实验四文件管理.zip

import java.io.File; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.List; import java.util.Scanner; public class Test { static final int FATsize = 16; static final int blocksize = 1024; static final int EMPTY_BLOCK = 0;//块空标志 static final int LAST_BLOCK = -1;//文件结束标志 static FCB catalogue;//全局目录 static FATNode[] fattable;//FAT表 static FCB currentdir;//时刻指向当前目录 static FCB targetdir;//指向目标路径 static String path;//要现实的当前路径 static File curfile; static void Init(){ //初始化作用:1.创建根目录 2.创建FAT表 并给根目录分配 catalogue = new FCB("根目录",1024,2); catalogue.fathernode = null;//没有父亲 fattable = new FATNode[FATsize]; for(int i=0; i<FATsize; ++i){//初始化FAT表 FATNode fn = new FATNode(EMPTY_BLOCK,null); fattable[i] = fn; } allocationFat(catalogue); currentdir = catalogue; path = catalogue.name; curfile = new File("D://"+catalogue.name); if (!(curfile.exists())){//创建文件 curfile.mkdir(); } //showFat(); } static List<Integer> findBlock(int neednum){ List<Integer> list = new ArrayList<>(); for(int i=0; i<fattable.length; ++i){ if(fattable[i].nextnode == EMPTY_BLOCK){ if(neednum <= 0){ return list; } list.add(i); --neednum; } } return list; } static void allocationFat(FCB fcb){//为文件分配外存(修改FATtable) int blocnum = (int) Math.ceil((double) fcb.size/1024); int remainder = fcb.size%1024; List list = findBlock(blocnum);//返回空闲块的下标数组; if(fcb.type == 1){//文件 if(list.size() == 1){//list的大小为1 fcb.first_block = (int) list.get(0); fattable[(int) list.get(0)].nextnode = LAST_BLOCK; fattable[(int) list.get(0)].otherinfo = fcb.name; }else{//list的大小大于1 for(int i=0; i<list.size()-1; ++i){ if(i == 0){//首块 fcb.first_block = (int) list.get(i); } fattable[(int) list.get(i)].nextnode = (int) list.get(i+1); fattable[(int) list.get(i)].otherinfo = fcb.name; } //单独处理最后一个 fattable[(int) list.get(list.size()-1)].nextnode = LAST_BLOCK; fattable[(int) list.get(list.size()-1)].otherinfo = fcb.name; } }else if(fcb.type == 2){//目录 fcb.first_block = (int) list.get(list.size()-1); fattable[(int) list.get(list.size()-1)].nextnode = LAST_BLOCK; fattable[(int) list.get(list.size()-1)].otherinfo = fcb.name; }else{//已删除文件 } } static void removeFcb(FCB fcb){//从FAT表中删除某文件 int poshead = fcb.first_block; int posbehind; do { posbehind = fattable[poshead].nextnode;//记录下一块的下标 fattable[poshead].nextnode = EMPTY_BLOCK; fattable[poshead].otherinfo = null; poshead = posbehind; }while(poshead != LAST_BLOCK); } static void show(){ boolean flag = true; while(flag){ Scanner sc = new Scanner(System.in); System.out.print(path+"/>$"); String str = sc.nextLine();//输入的命令及路径 String[] strs = str.split("[ /]");//经路径拆分 switch (strs[0]){ case "md"://创建子目录 targetdir = currentdir; for(int i=1; i<strs.length; ++i){ if (".".equals(strs[i])){//在本目录下创建目录 targetdir = currentdir; }else if("..".equals(strs[i])){//去上层目录创建创建目录 targetdir = targetdir.fathernode; }else{ FCB fcb = new FCB(strs[i],1024,2); allocationFat(fcb); fcb.fathernode = targetdir; targetdir.childlist.add(fcb); File mdfile = new File(curfile,fcb.name); if(! mdfile.exists()){//创建子目录 mdfile.mkdir(); } } } //showFat(); break; case "rd"://删除子目录 System.out.print("确定要删除目录"+strs[1]+"吗(Y/N)?:"); String choice = sc.nextLine(); if ("Y".equals(choice)){ FCB rdfcb = new FCB(strs[1],1024,2); if (currentdir.childlist.contains(rdfcb)){//找到了,准备删除 rdfcb = currentdir.childlist.get(currentdir.childlist.indexOf(rdfcb)); if(rdfcb.childlist.size() > 0){ System.out.println("不能删除"); }else{ removeFcb(rdfcb); currentdir.childlist.remove(rdfcb); File rdfile = new File(curfile,rdfcb.name); if(rdfile.exists()){ rdfile.delete(); } rdfcb = null; } }else{ System.out.println("子目录不存在"); } }else{} //showFat(); break; case "mk": String mkfcbname = strs[1]; int mkfcbsize = Integer.parseInt(strs[2]); FCB mkfcb = new FCB(mkfcbname,mkfcbsize,1); System.out.print("输入文件内容:"); String neirong = sc.nextLine(); mkfcb.context = neirong; allocationFat(mkfcb); mkfcb.fathernode = currentdir; currentdir.childlist.add(mkfcb); //showFat(); break; case "del": String delname = strs[1]; FCB delfcb = new FCB(delname,1024,1); System.out.print("确定要删除文件"+delfcb.name+"(Y/N)?:"); choice = sc.nextLine(); if ("Y".equals(choice)){ if (currentdir.childlist.contains(delfcb)){ delfcb = currentdir.childlist.get(currentdir.childlist.indexOf(delfcb)); removeFcb(delfcb); currentdir.childlist.remove(delfcb); delfcb = null; //showFat(); }else{ System.out.println("文件不存在"); } }else {} break; case "dir": currentdir.showF(); break; case "tree": showTree(catalogue); break; case "cd": for (int i=1; i<strs.length; ++i){ if(".".equals(strs[i])){// }else if("..".equals(strs[i])){//返回上一级 currentdir = currentdir.fathernode; curfile = curfile.getParentFile();