课堂练习之“寻找最长单词链”
package test; //20173522 李秦 import java.applet.Applet; import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; public class Lian2 { public static void main(String[] args) throws IOException { // TODO 自动生成的方法存根 String filename ="D:\\大二下\\软件工程\\input.txt"; File a=new File(filename); //judeFileExists(a); if(judeFileExists(a)) { danci(filename); } else { System.out.println("文件不存在"); } } public static void danci(String s) throws IOException { BufferedReader br = new BufferedReader(new FileReader(s)); StringBuffer sb = new StringBuffer(); String text = null; while ((text = br.readLine()) != null) { sb.append(text);// 将读取出的字符追加到stringbuffer中 } br.close(); // 关闭读入流 String str = sb.toString().toLowerCase(); // 将stringBuffer转为字符并转换为小写 String[] words = str.split("[^(a-zA-Z)]+"); // 非单词的字符来分割,得到所有单词 if(words.length==1) { if("".equals(words[0])) System.out.println("文件中无单词"); else System.out.println("文件中只有一个单词"); } else { StringBuffer yao = new StringBuffer(); String b1=words[0]; yao.append(b1); yao.append(" "); //System.out.println(b1); String end=b1.substring(b1.length()-1,b1.length()); //System.out.println(end); for(int i=1;i<words.length;i++) { String start=words[i].substring(0,1); if(end.equals(start)) { end=words[i].substring(words[i].length()-1,words[i].length()); yao.append(words[i]); yao.append(" "); } } String t=yao.toString(); if("apple ".equals(t)) { System.out.println("没有首尾相连的单词"); } File file =new File("D:\\大二下\\软件工程\\output1.txt"); try { file.createNewFile(); } catch (IOException e) { e.printStackTrace(); } try { FileWriter fw =new FileWriter(file); fw.write(yao.toString()); fw.flush(); fw.close(); } catch (IOException e) { e.printStackTrace(); } } } // 判断文件是否存在 public static boolean judeFileExists(File file) { if (file.exists()) { return true; } else { System.out.println("文件不存在"); // try { // file.createNewFile(); // } catch (IOException e) { // TODO Auto-generated catch block // e.printStackTrace(); // } return false; } } // 判断文件夹是否存在(未修改) public static void judeDirExists(File file) { if (file.exists()) { if (file.isDirectory()) { System.out.println("dir exists"); } else { System.out.println("the same name file exists, can not create dir"); } } else { System.out.println("dir not exists, create it ..."); file.mkdir(); } } }