源程序：
Text_2.java
import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.io.InputStreamReader; import java.text.DecimalFormat; import java.text.NumberFormat; import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.Scanner; public class Text_2 { static int N=5;public static String StatList(String str) {StringBuffer sb = new StringBuffer();HashMap<String ,Integer> has = new HashMap<String ,Integer> (); // 打开一个哈希表String[] slist = str.split("[^a-zA-Z\']+");for (int i = 0; i < slist.length; i++) {if (!has.containsKey(slist[i])) { has.put(slist[i], 1);} else {has.put(slist[i],has.get(slist[i])+1 );}}Iterator<String> iterator = has.keySet().iterator();String a[]=new String[100];int s[]=new int[100];int judge;int n;Scanner in=new Scanner(System.in);System.out.println("输入前n个最常出现的单词:");n=in.nextInt();for(int i=0;i<n;i++){iterator = has.keySet().iterator();while(iterator.hasNext()){String word = (String) iterator.next();if(s[i]<has.get(word)){s[i]=has.get(word);a[i]=word;}}judge=woor(a[i]);if(judge==1){n++;has.remove(a[i]);}else{sb.append("单词：").append(a[i]).append(" 次数").append(has.get(a[i])).append("\r\n");has.remove(a[i]);}}return sb.toString();}public static void main(String[] args) {display();// TODO Auto-generated method stub // ArrayList<String> fil=getFiles("a");//目录下的文件 // ArrayList<String> fil=getDirectory(file);//目录下的文件和子目录里的文件 // for(int i=0;i<fil.size();i++) // { // String filePath = fil.get(i); // String sz=writeFromFile.readTxtFile(filePath); // zimu(filePath); // String ltxt=null; // System.out.println(ltxt=StatList(sz)); // try { // writeFromFile.daochu(ltxt); // } catch (IOException e) { // // TODO Auto-generated catch block // e.printStackTrace(); // } // } }public static int woor(String a){int n=0;File ctoFile = new File("stopword.txt");InputStreamReader rdCto;try {rdCto = new InputStreamReader(new FileInputStream(ctoFile));BufferedReader bfReader = new BufferedReader(rdCto);String txtline = null;try {while ((txtline = bfReader.readLine()) != null) {if(txtline.equals(a)){n=1;}}bfReader.close();} catch (IOException e) {// TODO Auto-generated catch block e.printStackTrace();}} catch (FileNotFoundException e) {// TODO Auto-generated catch block e.printStackTrace();}// int n=0; // String[] biao= {"a","the","an","it","and","this","I","t","s"}; // for(int i=0;i<biao.length;i++) // { // if(biao[i].equals(a)) // { // n=1; // } // }return n;}public static ArrayList<String> getFiles(String path) {ArrayList<String> files = new ArrayList<String>();File file = new File(path);File[] tempList = file.listFiles();for (int i = 0; i < tempList.length; i++) {if (tempList[i].isFile()) {files.add(tempList[i].toString());}if (tempList[i].isDirectory()) {}}return files;}private static ArrayList<String> getDirectory(File file) {ArrayList<String> files = new ArrayList<String>();ArrayList<String> files1 = new ArrayList<String>();//获取该目录下的文件列表File flist[] = file.listFiles();for (File f : flist) {if (f.isDirectory()) {// 如果f是一个目录files1=getFiles(f.getAbsolutePath());files.addAll(files1);getDirectory(f);} else {//如果f是一个文件 files.add(f.getAbsolutePath());}}return files;}public static void zimu(String path){try {//IO操作读取文件内容FileReader fr = new FileReader(path);BufferedReader br = new BufferedReader(fr);DecimalFormat df = new DecimalFormat("#.00");HashMap<String, Integer> map = new HashMap<String, Integer>();String string =null;Integer count = 0;//每个字母的次数Integer total = 0;//总共多少个字母try {while ((string=br.readLine())!=null) {char[] ch = string.toCharArray();for (int i = 0; i < ch.length; i++) {if (ch[i] > 'A' && ch[i]< 'z') {total++;ch[i] = Character.toLowerCase(ch[i]);count = map.get(ch[i]+"");if (count == null) {count = 1;}else {count++;}map.put(ch[i]+"", count);}}}} catch (IOException e) {// TODO Auto-generated catch block e.printStackTrace();}ArrayList<String> list = new ArrayList<String>();list.addAll(map.keySet()); //将单词添加到list中NumberFormat numberFormat = NumberFormat.getInstance();// 设置精确到小数点后2位 numberFormat.setMaximumFractionDigits(2);//排序按照出现次数降序排列for(int i = 0;i < list.size();i++){for(int j = 0;j < (list.size() - i-1);j++) //list.size() - i-1因为要用到i+1要考虑是否超出范围的问题 {if(map.get(list.get(j)) < map.get(list.get(j+1))){String t = list.get(j);list.set(j, list.get(j+1));list.set( j+1, t);}}}for(int i = 0 ; i < list.size();i++){System.out.println(list.get(i) + ":" + map.get(list.get(i)) +" "+ df.format(((float)map.get(list.get(i)))*100/total) + "%");}} catch (FileNotFoundException e) {// TODO Auto-generated catch block e.printStackTrace();}}public static String StatList1(String str) {StringBuffer sb = new StringBuffer();HashMap<String ,Integer> has = new HashMap<String ,Integer> (); // 打开一个哈希表String[] slist = str.split("[^a-zA-Z\']+");for (int i = 0; i < slist.length; i++) {if (!has.containsKey(slist[i])) { has.put(slist[i], 1);} else {has.put(slist[i],has.get(slist[i])+1 );}}Iterator<String> iterator = has.keySet().iterator();String a[]=new String[100];int s[]=new int[100];int judge;int n=20;for(int i=0;i<n;i++){iterator = has.keySet().iterator();while(iterator.hasNext()){String word = (String) iterator.next();if(s[i]<has.get(word)){s[i]=has.get(word);a[i]=word;}}judge=woor(a[i]);if(judge==1){n++;has.remove(a[i]);}else{sb.append("单词：").append(a[i]).append(" 次数").append(has.get(a[i])).append("\r\n");has.remove(a[i]);}}return sb.toString();}public static String StatList2(String str) {StringBuffer sb = new StringBuffer();HashMap<String ,Integer> has = new HashMap<String ,Integer> (); // 打开一个哈希表String[] slist = str.split("[^a-zA-Z\']+");for (int i = 0; i < slist.length; i++) {if (!has.containsKey(slist[i])) { has.put(slist[i], 1);} else {has.put(slist[i],has.get(slist[i])+1 );}}Iterator<String> iterator = has.keySet().iterator();String a[]=new String[2000];int s[]=new int[2000];int judge;int n=1000;String duanyu="";for(int i=0;i<n;i++){iterator = has.keySet().iterator();while(iterator.hasNext()){String word = (String) iterator.next();if(s[i]<has.get(word)){s[i]=has.get(word);a[i]=word;}}judge=woor(a[i]);if(judge==1){n++;has.remove(a[i]);System.out.println(duanyu);duanyu="";}else{duanyu=duanyu+" "+a[i];has.remove(a[i]);}}return sb.toString();}public static void display(){File file = new File("a");int n=0;Scanner in=new Scanner(System.in);while(n!=5){System.out.println("请选择命令");System.out.println("5退出");System.out.println("1字母");System.out.println("2单词");System.out.println("3前n个单词");System.out.println("4短语");n=in.nextInt();if(n==1){zimu("a.txt");}if(n==2){String sz=writeFromFile.readTxtFile("a.txt");String ltxt=null;System.out.println(ltxt=StatList1(sz)); try {writeFromFile.daochu(ltxt);} catch (IOException e) {// TODO Auto-generated catch block e.printStackTrace();}}if(n==3){String sz=writeFromFile.readTxtFile("a.txt");String ltxt=null;System.out.println(ltxt=StatList(sz)); try {writeFromFile.daochu(ltxt);} catch (IOException e) {// TODO Auto-generated catch block e.printStackTrace();}}if(n==4){String sz=writeFromFile.readTxtFile("a.txt");String ltxt=null;System.out.println(ltxt=StatList2(sz)); try {writeFromFile.daochu(ltxt);} catch (IOException e) {// TODO Auto-generated catch block e.printStackTrace();}}}}}
writeFromFile.java
import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; //import java.io.Reader; //从文本文档中读入 public class writeFromFile {public static String readTxtFile(String filePath){ try { String encoding="GBK"; File file=new File(filePath); if(file.isFile() && file.exists()){ //判断文件是否存在 InputStreamReader read = new InputStreamReader( new FileInputStream(file),encoding);//考虑到编码格式 BufferedReader bufferedReader = new BufferedReader(read); String lineTxt = null;String lineText="";while((lineTxt = bufferedReader.readLine()) != null){ lineText+=(lineTxt); } read.close(); return lineText;}else{ System.out.println("找不到指定的文件"); } } catch (Exception e) { System.out.println("读取文件内容出错"); e.printStackTrace(); } return null;} public static void daochu(String a) throws IOException{File file=new File("b.txt");FileOutputStream fos=new FileOutputStream(file);OutputStreamWriter osw = new OutputStreamWriter(fos,"UTF-8");osw.append(a);osw.close();fos.close();} }
实验截图：
实验总结：
这次的实验在上次的基础上，要把上次的功能写成函数，分别进行调用，因为上次的实验我已经将功能写成函数，所以在这次的实验中写了一个界面，对函数进行了分别调用
