山东大学计算机网络课程设计Java实现FTP的类似的功能

package bean; import com.google.gson.Gson; import com.google.gson.JsonArray; import com.google.gson.internal.LinkedTreeMap; import com.sun.org.apache.regexp.internal.RE; import java.io.*; import java.math.RoundingMode; import java.nio.channels.NonWritableChannelException; import java.text.DecimalFormat; import java.util.*; /** * Created by 53196 on 2017/10/27. */ public class jsonUtil { private static DecimalFormat df = null; static { // 设置数字格式，保留一位有效小数 df = new DecimalFormat("#0.0"); df.setRoundingMode(RoundingMode.HALF_UP); df.setMinimumFractionDigits(1); df.setMaximumFractionDigits(1); } /** * 格式化文件大小 * @param length * @return */ public static String getFormatFileSize(long length) { double size = ((double) length) / (1 << 30); if(size >= 1) { return df.format(size) + "GB"; } size = ((double) length) / (1 << 20); if(size >= 1) { return df.format(size) + "MB"; } size = ((double) length) / (1 << 10); if(size >= 1) { return df.format(size) + "KB"; } return length + "B"; } public static user fromJson(String s){ Gson gson = new Gson(); user u = gson.fromJson(s , user.class); return u; } public static String toJson(user user){ Gson gson = new Gson(); return gson.toJson(user); } public static String JSONTokener(String in) { // consume an optional byte order mark (BOM) if it exists if (in != null && in.startsWith("\ufeff")) { in = in.substring(1); } return in; } // 读文件，返回字符串 public static String ReadFile(String path) { File file = new File(path); BufferedReader reader = null; String laststr = ""; try { // System.out.println("以行为单位读取文件内容，一次读一整行："); reader = new BufferedReader(new FileReader(file)); String tempString = null; // 一次读入一行，直到读入null为文件结束 while ((tempString = reader.readLine()) != null) { // 显示行号 laststr = laststr + tempString; } reader.close(); } catch (IOException e) { e.printStackTrace(); } finally { if (reader != null) { try { reader.close(); } catch (IOException e1) { } } } return laststr; } // 把json格式的字符串写到文件 public static boolean writeFile(String filePath, String sets) { FileWriter fw; try { fw = new FileWriter(filePath); PrintWriter out = new PrintWriter(fw); out.write(sets); out.println(); fw.close(); out.close(); return true; } catch (IOException e) { e.printStackTrace(); return false; } } //使用泛型的方法，恢复类型。 private static <T> List<T> StringTolist(String jsonString, Class<T[]> type) { Gson gson = new Gson(); T[] list = gson.fromJson(jsonString, type); return Arrays.asList(list); } public static boolean WriterUserMap(HashMap<String , user> userMap) { for (String key:userMap.keySet()){ for (int i = 0 ;i<userMap.get(key).getFileList().size();i++) { userMap.get(key).getFileList().get(i).setFilePath("path"); } } Gson gson = new Gson(); return jsonUtil.writeFile(System.getProperty("user.dir")+"/src/userMap",gson.toJson(userMap)); } public static HashMap<String , user> ReadJsonForUserMap(){ Gson gson = new Gson(); String s = jsonUtil.ReadFile(System.getProperty("user.dir")+"/src/userMap"); HashMap<String ,user> userMap = new HashMap<>(); HashMap map = gson.fromJson(s,HashMap.class); for (Object key:map.keySet()) { user u = new user(); LinkedTreeMap linkedTreeMap = (LinkedTreeMap)map.get(key.toString()); u.setUserName(linkedTreeMap.get("userName").toString()); u.setPassWord(linkedTreeMap.get("passWord").toString()); u.setOperate(0); String jsonString = linkedTreeMap.get("fileList").toString(); List<file> list = jsonUtil.StringTolist(jsonString,file[].class); ArrayList<file> fl = new ArrayList<>(); for (int i = 0;i<list.size();i++){ fl.add(list.get(i)); } u.setFileList(fl); userMap.put(u.getUserName(),u); } return userMap; } //获取时间 public static String time(){ String nowTime = ""; Calendar now = Calendar.getInstance(); nowTime += now.get(Calendar.HOUR_OF_DAY) +"时"; nowTime += now.get(Calendar.MINUTE) +"分"; nowTime += now.get(Calendar.YEAR) ; nowTime += (now.get(Calendar.MONTH)+1) ; nowTime += now.get(Calendar.DATE) ; return nowTime; } public static void main(String[] args){ /*user u = new user("username1","password"); file f = new file("filename","","","0"); u.getFileList().add(f); String s = jsonUtil.toJson(u); System.out.println(s); user u1 = jsonUtil.fromJson("{\"userName\":\"username233\",\"passWord\":\"password\",\"operate\":1,\"fileList\":[{\"fileName\":\"clientFile\",\"filePath\":\"\",\"fileSize\":\"\",\"filedate\":\"\"}],\"LOGIN\":1,\"UPLOAD\":2,\"DOWNLOAD\":3,\"DELETE\":4}"); System.out.println(u1.getUserName());*/ Gson gson = new Gson(); HashMap<String,user> userMap = new HashMap<>(); user u1 = new user("username","password"); user u2 = new user("leyinggang","123456"); userMap.put(u1.getUserName(),u1); userMap.put(u2.getUserName(),u2); jsonUtil.writeFile(System.getProperty("user.dir")+"/src/userMap",gson.toJson(userMap)); /*HashMap<String , user> map = jsonUtil.ReadJsonForUserMap(); System.out.println(map.get("username")); */ } }