西电JAVA程序上机作业1实验报告

JAVA程序上机作业1实验报告一．实验题目：文本统计器创建一个类，实现统计文本文件中各类字符和字符串的个数的功能，要求实现：按字符统计，输出各个字符的数量按单词统计，输出各个单词的数量在1(b)的基础上，实现一个类KeywordIdentifier，读入一个java程序源文件，输出各个关键字的个数（注意，注释中出现的关键字不计入关键字个数）二.实现过程及步骤：1.实现统计字符个数功能：publicstaticHashMap<Character,Integer>CharCounter(Strings){ for(inti=0;i<s.length();i++) { Characterc=s.charAt(i);//获得s中第i个字符;charAt(i)截取第i个字符 Integercountmap.get(c);//用字符c作为key值在map中查找value map.put(c,count==null?1:count+1);//如果value不为空,则表示出现过，数目会加1，如果为空，表示没出现，则数目为1 } returnmap;}2.实现统计单词个数功能：publicstaticvoidWordCounter(Stringstr){ String[]slist=str.split("\\b"); for(inti=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); } }}3.实现统计关键字个数功能：publicstaticvoidKeywordidentifier(Strings){String[]keyword={"public","static","int","if","else","for","class","break","return"};String[]slist=s.splist("\\b");for(inti=0;i<slist.length;i++){ for(Stringitem:keyword){if(item.equals(slist[i])){if(!key.containsKey(slist[i])){key.put(slist[i],1);}else{key.put(slist[i],key.get(slist[i])+1);}break;}}}}三．程序源代码：importjava.until.*;importjava.util.HashMap;importjava.io.*;publicclassCalculateWords{publicstaticHashMap<Character,Integer>map=newHashMap<Character,Integer>();publicstaticHashMap<String,Integer>has=newHashMap<String,Integer>();publicstaticHashMap<String,Integer>key=newHashMap<String,Integer>();//***********统计字符个数***************publicstaticHashMap<Character,Integer>CharCounter(Strings){ for(inti=0;i<s.length();i++) { Characterc=s.charAt(i);//获得s中第i个字符;charAt(i)截取第i个字符 Integercountmap.get(c);//用字符c作为key值在map中查找value map.put(c,count==null?1:count+1);//如果value不为空,则表示出现过，数目会加1，如果为空，表示没出现，则数目为1 } returnmap;}//************统计单词个数***************publicstaticvoidWordCounter(Stringstr){ String[]slist=str.split("\\b"); for(inti=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); } }}//***************统计关键字个数***************publicstaticvoidKeywordidentifier(Strings){String[]keyword={"public","static","int","if","else","for","class","break","return"};String[]slist=s.splist("\\b");for(inti=0;i<slist.length;i++){ for(Stringitem:keyword){if(item.equals(slist[i])){if(!key.containsKey(slist[i])){key.put(slist[i],1);}else{key.put(slist[i],key.get(slist[i])+1);}break;}}}}publicstaticvoidmain(String[]args)throwsIOException{longfilePoint=0;Strings;RandomAccessFilefile=newRandomAccessFile("in.txt","r");longfileLength=file.length();//获取文件长度while(filePoint<fileLength){s=file.readLine();//读取一行字符，并移动文件指针//统计每个字符的频率CharCounter(s);//统计每个单词的频率WordCounter(s);//统计关键字Keywordidentifier(s);filePoint=file.getFilePointer();}System.out.println(map);System.out.println(has);System.out.println(key);}}注：1.统计关键字时，只用了少量常见关键字；2.其中实验时读入文档“in.txt”为：“AlthoughastrongpoundandweakmarketsinAsiaplayaroleinthedownsizing,thelayoffsinStokehavetheirrootsinearthshakingsocialshifts.AspokesmanforRoyalDoultonadmittedthatthecompany"hasbeensomewhatslowincatchingupwiththetrend"towardcasualdining.Familieseattogetherlessoften,heexplained